Compiler Features:
- Assembler: Use
push0
for placing0
on the stack for EVM versions starting from "Shanghai". This decreases the deployment and runtime costs. - EVM: Set default EVM version to "Shanghai".
- EVM: Support for the EVM Version "Shanghai".
- NatSpec: Add support for NatSpec documentation in
enum
definitions. - NatSpec: Add support for NatSpec documentation in
struct
definitions. - NatSpec: Include NatSpec from events that are emitted by a contract but defined outside of it in userdoc and devdoc output.
- Optimizer: Re-implement simplified version of
UnusedAssignEliminator
andUnusedStoreEliminator
. It can correctly remove some unused assignments in deeply nested loops that were ignored by the old version. - Parser: Unary plus is no longer recognized as a unary operator in the AST and triggers an error at the parsing stage (rather than later during the analysis).
- SMTChecker: Group all messages about unsupported language features in a single warning. The CLI option
--model-checker-show-unsupported
and the JSON optionsettings.modelChecker.showUnsupported
can be enabled to show the full list. - SMTChecker: Properties that are proved safe are now reported explicitly at the end of analysis. By default, only the number of safe properties is shown. The CLI option
--model-checker-show-proved-safe
and the JSON optionsettings.modelChecker.showProvedSafe
can be enabled to show the full list of safe properties. - Standard JSON Interface: Add experimental support for importing ASTs via Standard JSON.
- Yul EVM Code Transform: If available, use
push0
instead ofcodesize
to produce an arbitrary value on stack in order to create equal stack heights between branches.
Bugfixes:
- ABI: Include events in the ABI that are emitted by a contract but defined outside of it.
- Immutables: Disallow initialization of immutables in try/catch statements.
- SMTChecker: Fix false positives in ternary operators that contain verification targets in its branches, directly or indirectly.
AST Changes:
- AST: Add the
internalFunctionIDs
field to the AST nodes of contracts containing IDs of functions that may be called via the internal dispatch. The field is a map from function AST IDs to internal dispatch function IDs. These IDs are always generated, but they are only used in via-IR code generation. - AST: Add the
usedEvents
field toContractDefinition
which contains the AST IDs of all events emitted by the contract as well as all events defined and inherited by the contract.
Language Features:
- Allow defining custom operators for user-defined value types via
using {f as +} for T global
syntax.
Compiler Features:
- SMTChecker: New trusted mode that assumes that any compile-time available code is the actual used code even in external calls. This can be used via the CLI option
--model-checker-ext-calls trusted
or the JSON fieldsettings.modelChecker.extCalls: "trusted"
.
Bugfixes:
- Assembler: Avoid duplicating subassembly bytecode where possible.
- Code Generator: Avoid including references to the deployed label of referenced functions if they are called right away.
- ContractLevelChecker: Properly distinguish the case of missing base constructor arguments from having an unimplemented base function.
- SMTChecker: Fix internal error caused by unhandled
z3
expressions that come from the solver when bitwise operators are used. - SMTChecker: Fix internal error when using the custom NatSpec annotation to abstract free functions.
- TypeChecker: Also allow external library functions in
using for
.
AST Changes:
- AST: Add
function
field toUnaryOperation
andBinaryOperation
AST nodes.functionList
inUsingForDirective
AST nodes will now containoperator
anddefinition
members instead offunction
when the list entry defines an operator.
Language Features:
- Allow named parameters in mapping types.
Compiler Features:
- Commandline Interface: Add
--no-cbor-metadata
that skips CBOR metadata from getting appended at the end of the bytecode. - Commandline Interface: Return exit code
2
on uncaught exceptions. - EVM: Deprecate
block.difficulty
and disallowdifficulty()
in inline assembly for EVM versions >= paris. The change is due to the renaming introduced by EIP-4399. - EVM: Introduce
block.prevrandao
in Solidity andprevrandao()
in inline assembly for EVM versions >= paris. - EVM: Set the default EVM version to "Paris".
- EVM: Support for the EVM version "Paris".
- Language Server: Add basic document hover support.
- Natspec: Add event Natspec inheritance for devdoc.
- Optimizer: Added optimization rule
and(shl(X, Y), shl(X, Z)) => shl(X, and(Y, Z))
. - Parser: More detailed error messages about invalid version pragmas.
- SMTChecker: Make
z3
the default solver for the BMC and CHC engines instead of all solvers. - SMTChecker: Support Eldarica as a Horn solver for the CHC engine when using the CLI option
--model-checker-solvers eld
. The binaryeld
must be available in the system. - Solidity Upgrade Tool: Remove
solidity-upgrade
tool. - Standard JSON: Add a boolean field
settings.metadata.appendCBOR
that skips CBOR metadata from getting appended at the end of the bytecode. - TypeChecker: Warn when using deprecated builtin
selfdestruct
. - Yul EVM Code Transform: Generate more optimal code for user-defined functions that always terminate a transaction. No return labels will be pushed for calls to functions that always terminate.
- Yul Optimizer: Allow replacing the previously hard-coded cleanup sequence by specifying custom steps after a colon delimiter (
:
) in the sequence string. - Yul Optimizer: Eliminate
keccak256
calls if the value was already calculated by a previous call and can be reused.
Bugfixes:
- Parser: Disallow several
indexed
attributes for the same event parameter. - Parser: Disallow usage of the
indexed
attribute for modifier parameters. - SMTChecker: Fix display error for negative integers that are one more than powers of two.
- SMTChecker: Fix internal error on chain assignments using static fully specified state variables.
- SMTChecker: Fix internal error on multiple wrong SMTChecker natspec entries.
- SMTChecker: Fix internal error when a public library function is called internally.
- SMTChecker: Fix internal error when deleting struct member of function type.
- SMTChecker: Fix internal error when using user-defined types as mapping indices or struct members.
- SMTChecker: Improved readability for large integers that are powers of two or almost powers of two in error messages.
- TypeChecker: Fix bug where private library functions could be attached with
using for
outside of their declaration scope. - Yul Optimizer: Hash hex and decimal literals according to their value instead of their representation, improving the detection of equivalent functions.
Important Bugfixes:
- Yul Optimizer: Prevent the incorrect removal of storage writes before calls to Yul functions that conditionally terminate the external EVM call.
Compiler Features:
- Code Generator: More efficient overflow checks for multiplication.
- Language Server: Analyze all files in a project by default (can be customized by setting
'file-load-strategy'
to'directly-opened-and-on-import'
in LSP settings object). - Yul Optimizer: Simplify the starting offset of zero-length operations to zero.
Bugfixes:
- Type Checker: Fix internal compiler error on tuple assignments with invalid left-hand side.
- Yul IR Code Generation: Fix internal compiler error when accessing the
.slot
member of a mapping through a storage reference in inline assembly.
Build System:
- Allow disabling pedantic warnings and do not treat warnings as errors during compiler build when
-DPEDANTIC=OFF
flag is passed to CMake. - Update emscripten to version 3.1.19.
Important Bugfixes:
- Code Generation: Fix data corruption that affected ABI-encoding of calldata values represented by tuples: structs at any nesting level; argument lists of external functions, events and errors; return value lists of external functions. The 32 leading bytes of the first dynamically-encoded value in the tuple would get zeroed when the last component contained a statically-encoded array.
Compiler Features:
- Code Generator: More efficient code for checked addition and subtraction.
- TypeChecker: Support using library constants in initializers of other constants.
- Yul IR Code Generation: Improved copy routines for arrays with packed storage layout.
- Yul Optimizer: Add rule to convert
mod(add(X, Y), A)
intoaddmod(X, Y, A)
, ifA
is a power of two. - Yul Optimizer: Add rule to convert
mod(mul(X, Y), A)
intomulmod(X, Y, A)
, ifA
is a power of two.
Bugfixes:
- Commandline Interface: Disallow the following options outside of the compiler mode:
--via-ir
,--metadata-literal
,--metadata-hash
,--model-checker-show-unproved
,--model-checker-div-mod-no-slacks
,--model-checker-engine
,--model-checker-invariants
,--model-checker-solvers
,--model-checker-timeout
,--model-checker-contracts
,--model-checker-targets
. - Type Checker: Fix compiler crash on tuple assignments involving certain patterns with unary tuples on the left-hand side.
- Type Checker: Fix compiler crash when
abi.encodeCall
received a tuple expression instead of an inline tuple. - Type Checker: Fix null dereference in
abi.encodeCall
type checking of free function.
Important Bugfixes:
- Code Generation: Avoid writing dirty bytes to storage when copying
bytes
arrays. - Yul Optimizer: Keep all memory side-effects of inline assembly blocks.
Language Features:
- Add
E.selector
for a non-anonymous eventE
to access the 32-byte selector topic.
Compiler Features:
- Language Server: Add rudimentary support for semantic highlighting.
- Language Server: Adds support for configuring
include-paths
JSON settings object that can be passed during LSP configuration stage. - Language Server: Always add
{project_root}/node_modules
to include search paths. - Type Checker: Warn about assignments involving multiple pushes to storage
bytes
that may invalidate references. - Yul Optimizer: Improve inlining heuristics for via IR code generation and pure Yul compilation.
Bugfixes:
- ABI Encoder: When encoding an empty string coming from storage do not add a superfluous empty slot for data.
- Common Subexpression Eliminator: Process assembly items in chunks with maximum size of 2000. It helps to avoid extremely time-consuming searches during code optimization.
- DocString Parser: Fix ICE caused by an immutable struct with mapping.
- Yul IR Code Generation: More robust cleanup in corner cases during memory to storage copies.
- Yul Optimizer: Do not remove
returndatacopy
in cases in which it might perform out-of-bounds reads that unconditionally revert as out-of-gas. Previously, anyreturndatacopy
that wrote to memory that was never read from was removed without accounting for the out-of-bounds condition.
Important Bugfixes:
- ABI Encoder: When ABI-encoding values from calldata that contain nested arrays, correctly validate the nested array length against
calldatasize()
in all cases. - Override Checker: Allow changing data location for parameters only when overriding external functions.
Compiler Features:
- Assembly-Json Exporter: Include source list in
sourceList
field. - Commandline Interface: Option
--pretty-json
works also with the following options:--abi
,--asm-json
,--ast-compact-json
,--devdoc
,--storage-layout
,--userdoc
. - Language Server: Allow full filesystem access to language server.
- Peephole Optimizer: Remove operations without side effects before simple terminations.
- SMTChecker: Support
abi.encodeCall
taking into account the called selector.
Bugfixes:
- Assembly-Json Exporter: Fix assembly json export to store jump types of operations in
jumpType
field instead ofvalue
. - SMTChecker: Fix ABI compatibility with z3 >=4.8.16.
- SMTChecker: Fix bug when z3 is selected but not available at runtime.
- Type Checker: Properly check restrictions of
using ... global
in conjunction with libraries. - TypeChecker: Convert parameters of function type to how they would be called for
abi.encodeCall
.
Important Bugfixes:
- Code Generator: Correctly encode literals used in
abi.encodeCall
in place of fixed bytes arguments.
Language Features:
- General: Allow annotating inline assembly as memory-safe to allow optimizations and stack limit evasion that rely on respecting Solidity's memory model.
- General:
using M for Type;
is allowed at file level andM
can now also be a brace-enclosed list of free functions or library functions. - General:
using ... for T global;
is allowed at file level where the user-defined typeT
has been defined, resulting in the effect of the statement being available everywhereT
is available.
Compiler Features:
- Commandline Interface: Allow the use of
--via-ir
in place of--experimental-via-ir
. - Compilation via Yul IR is no longer marked as experimental.
- JSON-AST: Added selector field for errors and events.
- Language Server: Implements goto-definition.
- Peephole Optimizer: Optimize comparisons in front of conditional jumps and conditional jumps across a single unconditional jump.
- Yul EVM Code Transform: Avoid unnecessary
pop
s on terminating control flow. - Yul IR Code Generation: When the result of an external call is statically-sized, ignore any returndata past the size expected by the compiler.
- Yul Optimizer: Remove
sstore
andmstore
operations that are never read from.
Bugfixes:
- General: Fix internal error for locales with unusual capitalization rules. Locale set in the environment is now completely ignored.
- Type Checker: Fix incorrect type checker errors when importing overloaded functions.
- Yul IR Code Generation: Optimize embedded creation code with correct settings. This fixes potential mismatches between the constructor code of a contract compiled in isolation and the bytecode in
type(C).creationCode
, resp. the bytecode used fornew C(...)
.
Language Features:
- General: Add equality-comparison operators for external function types.
- General: Support
ContractName.functionName
forabi.encodeCall
, in addition to external function pointers.
Compiler Features:
- Commandline Interface: Event and error signatures are also returned when using
--hashes
. - Yul Optimizer: Remove
mstore
andsstore
operations if the slot already contains the same value. - Yul: Emit immutable references for pure yul code when requested.
Bugfixes:
- Antlr Grammar: Allow builtin names in
yulPath
to support.address
in function pointers. - Code Generator: Fix internal error when accessing the members of external functions occupying more than two stack slots.
- Code Generator: Fix internal error when doing an explicit conversion from
string calldata
tobytes
. - Control Flow Graph: Perform proper virtual lookup for modifiers for uninitialized variable and unreachable code analysis.
- General:
string.concat
now properly takes strings as arguments and returnsstring memory
. It was accidentally introduced as a copy ofbytes.concat
before. - Immutables: Fix wrong error when the constructor of a base contract uses
return
and the derived contract contains immutable variables. - Inheritance: Consider functions in all ancestors during override analysis.
- IR Generator: Add missing cleanup during the conversion of fixed bytes types to smaller fixed bytes types.
- IR Generator: Add missing cleanup for indexed event arguments of value type.
- IR Generator: Fix internal error when copying reference types in calldata and storage to struct or array members in memory.
- IR Generator: Fix IR syntax error when copying storage arrays of structs containing functions.
- Natspec: Fix internal error when overriding a struct getter with a Natspec-documented return value and the name in the struct is different.
- Type Checker: Fix internal error when a constant variable declaration forward references a struct.
- Yul EVM Code Transform: Improved stack shuffling in corner cases.
Solc-Js:
- The wrapper now requires at least nodejs v10.
- The code has been ported to TypeScript.
Build System:
- Emscripten builds store the embedded WebAssembly binary in LZ4 compressed format and transparently decompress on loading.
Language Features:
- General: New builtin function
abi.encodeCall(functionPointer, (arg1, arg2, ...))
that type-checks the arguments and returns the ABI-encoded function call data.
Compiler Features:
- Commandline Interface: Add
--lsp
option to getsolc
to act as a Language Server (LSP) communicating over stdio.
Bugfixes:
- Code Generator: Fix a crash when using
@use-src
and compiling from Yul to ewasm. - SMTChecker: Fix internal error when an unsafe target is solved more than once and the counterexample messages are different.
- SMTChecker: Fix soundness of assigned storage/memory local pointers that were not erasing enough knowledge.
- Fix internal error when a function has a calldata struct argument with an internal type inside.
- IR Generator: Fix IR syntax error when copying storage arrays of functions.
Language Features:
- Inline Assembly: Support
.address
and.selector
on external function pointers to access their address and function selector.
Compiler Features:
- Code Generator: Skip existence check for external contract if return data is expected. In this case, the ABI decoder will revert if the contract does not exist.
- Commandline Interface: Accept nested brackets in step sequences passed to
--yul-optimizations
. - Commandline Interface: Add
--debug-info
option for selecting how much extra debug information should be included in the produced EVM assembly and Yul code. - Commandline Interface: Support
--asm
,--bin
,--ir-optimized
,--ewasm
and--ewasm-ir
output selection options in assembler mode. - Commandline Interface: Use different colors when printing errors, warnings and infos.
- JSON AST: Set absolute paths of imports earlier, in the
parsing
stage. - SMTChecker: Output values for
block.*
,msg.*
andtx.*
variables that are present in the called functions. - SMTChecker: Report contract invariants and reentrancy properties. This can be enabled via the CLI option
--model-checker-invariants
or the Standard JSON optionsettings.modelChecker.invariants
. - Standard JSON: Accept nested brackets in step sequences passed to
settings.optimizer.details.yulDetails.optimizerSteps
. - Standard JSON: Add
settings.debug.debugInfo
option for selecting how much extra debug information should be included in the produced EVM assembly and Yul code. - Yul EVM Code Transform: Switch to new optimized code transform when compiling via Yul with enabled optimizer.
- Yul Optimizer: Take control-flow side-effects of user-defined functions into account in various optimizer steps.
Bugfixes:
- Code Generator: Fix constructor source mappings for immutables.
- Commandline Interface: Disallow
--error-recovery
option outside of the compiler mode. - Commandline Interface: Don't return zero exit code when writing linked files to disk fails.
- Commandline Interface: Fix extra newline character being appended to sources passed through standard input, affecting their hashes.
- Commandline Interface: Report output selection options unsupported by the selected input mode instead of ignoring them.
- Commandline Interface: When linking only accept exact matches for library names passed to the
--libraries
option. Library names not prefixed with a file name used to match any library with that name. - SMTChecker: Fix internal error in magic type access (
block
,msg
,tx
). - SMTChecker: Fix internal error in the CHC engine when passing gas in the function options.
- TypeChecker: Fix internal error when using arrays and structs with user defined value types before declaration.
- TypeChecker: Fix internal error when using user defined value types in public library functions.
- TypeChecker: Improved error message for constant variables with (nested) mapping types.
- Yul Assembler: Fix internal error when function names are not unique.
- Yul IR Generator: Do not output empty switches/if-bodies for empty contracts.
Important Bugfixes in Experimental Features:
- Yul IR Generator: Changes to function return variables referenced in modifier invocation arguments were not properly forwarded if there was more than one return variable.
Build System:
- Pass linker-only emscripten options only when linking.
- Remove obsolete compatibility workaround for emscripten builds.
- Update emscripten to version 2.0.33.
Important Bugfixes:
- Immutables: Properly perform sign extension on signed immutables.
- User Defined Value Type: Fix storage layout of user defined value types for underlying types shorter than 32 bytes.
Bugfixes:
- AST: Export
canonicalName
forUserDefinedValueTypeDefinition
andContractDefinition
.
Language Features:
- Inheritance: A function that overrides only a single interface function does not require the
override
specifier. - Type System: Support
type(E).min
andtype(E).max
for enums. - User Defined Value Type: allows creating a zero cost abstraction over a value type with stricter type requirements.
Compiler Features:
- Commandline Interface: Add
--include-path
option for specifying extra directories that may contain importable code (e.g. packaged third-party libraries). - Commandline Interface: Do not implicitly run evm bytecode generation unless needed for the requested output.
- Commandline Interface: Normalize paths specified on the command line and make them relative for files located inside base path and/or include paths.
- Immutable variables can be read at construction time once they are initialized.
- SMTChecker: Add constraints to better correlate
address(this).balance
andmsg.value
. - SMTChecker: Support constants via modules.
- SMTChecker: Support low level
call
as external calls to unknown code. - SMTChecker: Support the
value
option for external function calls. - SMTChecker: Support user defined value types.
Bugfixes:
- Code Generator: Fix ICE on assigning to calldata structs and statically-sized calldata arrays in inline assembly.
- Code Generator: Use stable source order for ABI functions.
- Commandline Interface: Disallow the
--experimental-via-ir
option in Standard JSON, Assembler and Linker modes. - Commandline Interface: Fix resolution of paths whitelisted with
--allowed-paths
or implicitly due to base path, remappings and files being compiled. Correctly handle paths that do not match imports exactly due to being relative, non-normalized or empty. - Commandline Interface: Report optimizer options as invalid in Standard JSON and linker modes instead of ignoring them.
- Name Resolver: Fix that when importing an aliased symbol using
import {AliasedName} from "a.sol"
it would use the original name of the symbol and not the aliased one. - Opcode Optimizer: Prevent the optimizer from running multiple times to avoid potential bytecode differences for referenced code.
- Parser: Properly check for multiple SPDX license identifiers next to each other and validate them.
- SMTChecker: Fix BMC's constraints regarding internal functions.
- SMTChecker: Fix false negative caused by
push
on storage array references returned by internal functions. - SMTChecker: Fix false positive in external calls from constructors.
- SMTChecker: Fix internal error on some multi-source uses of
abi.*
, cryptographic functions and constants. - Standard JSON: Fix non-fatal errors in Yul mode being discarded if followed by a fatal error.
- Type Checker: Correct wrong error message in inline assembly complaining about
.slot
or.offset
not valid when actually.length
was used. - Type Checker: Disallow modifier declarations and definitions in interfaces.
- Yul Optimizer: Fix a crash in LoadResolver, when
keccak256
has particular non-identifier arguments.
Language Features:
- Introduce global
block.basefee
for retrieving the base fee of the current block. - Yul: Introduce builtin
basefee()
for retrieving the base fee of the current block.
Compiler Features:
- AssemblyStack: Also run opcode-based optimizer when compiling Yul code.
- Commandline Interface: option
--pretty-json
works also with--standard--json
. - EVM: Set the default EVM version to "London".
- SMTChecker: Do not check underflow and overflow by default.
- SMTChecker: Unproved targets are hidden by default, and the SMTChecker only states how many unproved targets there are. They can be listed using the command line option
--model-checker-show-unproved
or the JSON optionsettings.modelChecker.showUnproved
. - SMTChecker: new setting to enable/disable encoding of division and modulo with slack variables. The command line option is
--model-checker-div-mod-slacks
and the JSON option issettings.modelChecker.divModWithSlacks
. - Yul EVM Code Transform: Also pop unused argument slots for functions without return variables (under the same restrictions as for functions with return variables).
- Yul EVM Code Transform: Do not reuse stack slots that immediately become unreachable.
- Yul Optimizer: Move function arguments and return variables to memory with the experimental Stack Limit Evader (which is not enabled by default).
Bugfixes:
- Code Generator: Fix crash when passing an empty string literal to
bytes.concat()
. - Code Generator: Fix internal compiler error when calling functions bound to calldata structs and arrays.
- Code Generator: Fix internal compiler error when passing a 32-byte hex literal or a zero literal to
bytes.concat()
by disallowing such literals. - Commandline Interface: Apply
--optimizer-runs
option in assembly / yul mode. - Commandline Interface: Fix crash when a directory path is passed to
--standard-json
. - Commandline Interface: Read JSON from standard input when
--standard-json
gets-
as a file name. - Standard JSON: Include source location for errors in files with empty name.
- Type Checker: Fix internal error and prevent static calls to unimplemented modifiers.
- Yul Code Generator: Fix internal compiler error when using a long literal with bitwise negation.
- Yul Code Generator: Fix source location references for calls to builtin functions.
- Yul Parser: Fix source location references for
if
statements.
Language Features:
- Yul: Special meaning of
".metadata"
data object in Yul object.
Bugfixes:
- Control Flow Graph: Fix incorrectly reported unreachable code.
- Solc-Js: When running
solcjs
without the--optimize
flag, usesettings.optimizer.enabled=false
in Standard JSON instead of omitting the key. - Standard JSON: Omitting
settings.optimizer.enabled
was not equivalent to setting it tofalse
. It meant disabling also the peephole optimizer and jumpdest remover which by default still run withenabled=false
.
Language Features:
- Allowing conversion from
bytes
andbytes
slices tobytes1
/.../bytes32
. - Yul: Add
verbatim
builtin function to inject arbitrary bytecode.
Compiler Features:
- Code Generator: Insert helper functions for panic codes instead of inlining unconditionally. This can reduce costs if many panics (checks) are inserted, but can increase costs where few panics are used.
- EVM: Set the default EVM version to "Berlin".
- SMTChecker: Function definitions can be annotated with the custom Natspec tag
custom:smtchecker abstract-function-nondet
to be abstracted by a nondeterministic value when called. - Standard JSON / combined JSON: New artifact "functionDebugData" that contains bytecode offsets of entry points of functions and potentially more information in the future.
- Yul Optimizer: Evaluate
keccak256(a, c)
, when the value at memory locationa
is known at compile time andc
is a constant<= 32
.
Bugfixes:
- AST: Do not output value of Yul literal if it is not a valid UTF-8 string.
- Code Generator: Fix internal error when function arrays are assigned to storage variables and the function types can be implicitly converted but are not identical.
- Code Generator: Fix internal error when super would have to skip an unimplemented function in the virtual resolution order.
- Control Flow Graph: Assume unimplemented modifiers use a placeholder.
- Control Flow Graph: Take internal calls to functions that always revert into account for reporting unused or unassigned variables.
- Function Call Graph: Fix internal error connected with circular constant references.
- Name Resolver: Do not issue shadowing warning if the shadowing name is not directly accessible.
- Natspec: Allow multiple
@return
tags on public state variable documentation. - SMTChecker: Fix internal error on conversion from
bytes
tofixed bytes
. - SMTChecker: Fix internal error on external calls from the constructor.
- SMTChecker: Fix internal error on struct constructor with fixed bytes member initialized with string literal.
- Source Locations: Properly set source location of scoped blocks.
- Standard JSON: Properly allow the
inliner
setting undersettings.optimizer.details
. - Type Checker: Fix internal compiler error related to having mapping types in constructor parameter for abstract contracts.
- Type Checker: Fix internal compiler error when attempting to use an invalid external function type on pre-byzantium EVMs.
- Type Checker: Fix internal compiler error when overriding receive ether function with one having different parameters during inheritance.
- Type Checker: Make errors about (nested) mapping type in event or error parameter into fatal type errors.
- Type Checker: Fix internal compiler error when overriding an implemented modifier with an unimplemented one.
AST Changes:
- Add member
hexValue
for Yul string and hex literals.
Important Bugfixes:
- ABI Decoder V2: For two-dimensional arrays and specially crafted data in memory, the result of
abi.decode
can depend on data elsewhere in memory. Calldata decoding is not affected.
Language Features:
- Assembly / Yul: Allow hex string literals.
- Possibility to use
bytes.concat
with variable number ofbytes
andbytesNN
arguments which behaves as a restricted version ofabi.encodePacked
with a more descriptive name. - Support custom errors via the
error
keyword and introduce therevert
statement.
Compiler Features:
- Analysis: Properly detect circular references to the bytecode of other contracts across all function calls.
- Commandline Interface: Model checker option
--model-checker-targets
also acceptsoutOfBounds
. - Commandline Interface: New model checker option
--model-checker-contracts
allows users to select which contracts should be analyzed as the most derived. - Low-Level Inliner: Inline ordinary jumps to small blocks and jumps to small blocks that terminate.
- NatSpec: Allow
@notice
tag on non-public state variables and local variable declarations. The documentation will only be part of the AST, under the fielddocumentation
. - SMTChecker: Deprecate
pragma experimental SMTChecker;
and set default model checker engine tonone
. - SMTChecker: Report local variables in CHC counterexamples.
- SMTChecker: Report out of bounds index access for arrays and fixed bytes.
- SMTChecker: Support file level functions and constants.
- Standard JSON: Model checker option
settings.modelChecker.targets
also acceptsoutOfBounds
. - Standard JSON: Model checker option
settings.modelChecker.targets
takes an array of string targets instead of string of comma separated targets. - Standard JSON: New model checker option
settings.modelChecker.contracts
allows users to select which contracts should be analyzed as the most derived. - Yul EVM Code Transform: Stack Optimization: Reuse slots of unused function arguments and defer allocating stack slots for return variables until after expression statements and assignments that do not reference them.
- Yul Optimizer: Added a new step FunctionSpecializer, that specializes a function with its literal arguments.
Bugfixes:
- Antlr Grammar: Fix parsing of import paths involving properly distinguishing between empty and non-empty string literals in general.
- AST Output: Fix
kind
field ofModifierInvocation
for base constructor calls. - Commandline interface: Fix internal error when printing AST and using
--base-path
orfile://
prefix in imports. - Commandline interface: Fix standard input bypassing allowed path checks.
- Natspec: Fix internal error related to the
@returns
documentation for a public state variable overriding a function. - SMTChecker: Fix false positive and false negative on
push
as LHS of a compound assignment. - SMTChecker: Fix false positive in contracts that cannot be deployed.
- SMTChecker: Fix internal error on public getter returning dynamic data on older EVM versions where these are not available.
- SMTChecker: Fix internal error on try-catch with function call in catch block.
- Type Checker: Fix missing error when events are used without an emit statement.
AST Changes:
- New property for
ContractDefinition
nodes:usedErrors
lists AST IDs of all errors used by the contract (even if defined outside).
Important Bugfixes:
- Optimizer: Fix bug on incorrect caching of Keccak-256 hashes.
Compiler Features:
- Command Line Interface: Drop experimental support for
--machine evm15
. - Optimizer: Try to move
and
with constant insideor
to improve storage writes of small types. - Optimizer: Replace multiplications and divisions with powers of two by shifts.
Bugfixes:
- AST Import: For constructors, a public visibility is ignored during importing.
- Error Reporter: Fix handling of carriage return.
- SMTChecker: Fix internal error in BMC on resolving virtual functions inside branches.
- SMTChecker: Fix internal error on
array.pop
nested inside 1-tuple. - SMTChecker: Fix internal error on
FixedBytes
constant initialized with string literal. - SMTChecker: Fix internal error on array slices.
- SMTChecker: Fix internal error on calling public getter on a state variable of type array (possibly nested) of structs.
- SMTChecker: Fix internal error on pushing to
string
casted tobytes
. - SMTChecker: Fix bug in virtual functions called by constructors.
AST Changes:
- ModifierInvocation: Add
kind
field which can bemodifierInvocation
orbaseConstructorSpecifier
.
Compiler Features:
- AST: Export NatSpec comments above each statement as their documentation.
- Inline Assembly: Do not warn anymore about variables or functions being shadowed by EVM opcodes.
- NatSpec: Provide source locations for parsing errors.
- Optimizer: Simple inlining when jumping to small blocks that jump again after a few side-effect free opcodes.
- NatSpec: Allow and export all tags that start with
@custom:
.
Bugfixes:
- AST: Added
referencedDeclaration
for enum members. - Code Generator: Fix internal error when functions are passed as parameters of other callables, when the function types can be implicitly converted, but not identical.
- Parser: Properly parse
.address
in some situations. - SMTChecker: Fix missing type constraints on block and transaction variables in the deployment phase.
- Type Checker: Fix internal error when override specifier is not a contract.
- Type Checker: Make function-hash collision errors into fatal type errors.
AST Changes:
- Adds
nameLocation
to declarations to represent the exact location of the symbolic name. - Removed the redundant function type "bytearraypush" - replaced by "arraypush".
- Support field
documentation
to hold NatSpec comments above each statement.
Language Features:
- Possibility to use
catch Panic(uint code)
to catch a panic failure from an external call.
Compiler Features:
- Code Generator: Reduce the cost of
<address>.code.length
by usingextcodesize
directly. - Command Line Interface: Allow
=
as separator between library name and address in--libraries
commandline option. - Command Line Interface: New option
--model-checker-targets
allows specifying which targets should be checked. The valid options areall
,constantCondition
,underflow
,overflow
,divByZero
,balance
,assert
,popEmptyArray
, where the default isall
. Multiple targets can be chosen at the same time, separated by a comma without spaces:underflow,overflow,assert
. - Command Line Interface: Only accept library addresses with a prefix of
0x
in--libraries
commandline option. - Optimizer: Add rule to replace
iszero(sub(x,y))
byeq(x,y)
. - Parser: Report meaningful error if parsing a version pragma failed.
- SMTChecker: Output internal and trusted external function calls in a counterexample's transaction trace.
- SMTChecker: Show
msg.value
in counterexample transaction traces when greater than 0. - SMTChecker: Show contract name in counterexample function call.
- SMTChecker: Support ABI functions as uninterpreted functions.
- SMTChecker: Support try/catch statements.
- SMTChecker: Synthesize untrusted functions called externally.
- SMTChecker: Use checked arithmetic by default and support
unchecked
blocks. - Standard JSON: New option
modelCheckerSettings.targets
allows specifying which targets should be checked. The valid options areall
,constantCondition
,underflow
,overflow
,divByZero
,balance
,assert
,popEmptyArray
, where the default isall
. Multiple targets can be chosen at the same time, separated by a comma without spaces:underflow,overflow,assert
.
Bugfixes:
- Code Generator: Fix length check when decoding malformed error data in catch clause.
- Control Flow Graph: Fix missing error caused by read from/write to uninitialized variables.
- SMTChecker: Fix false negatives in overriding modifiers and functions.
- SMTChecker: Fix false negatives in the presence of inline assembly.
- SMTChecker: Fix false negatives when analyzing external function calls.
- SMTChecker: Fix internal error on
block.chainid
. - SMTChecker: Fix internal error on pushing string literal to
bytes
array. - SMTChecker: Fix missing type constraints for block variables.
- Type Checker: Fix infinite loop when accessing circular constants from inline assembly.
- Type Checker: Fix internal error caused by constant structs containing mappings.
- Type System: Disallow implicit conversion from
uintN
tointM
whenM > N
, and by extension, explicit conversion between the same types is also disallowed.
Build System:
- Update the soljson.js build to emscripten 2.0.12 and boost 1.75.0.
Breaking Changes:
- Code Generator: All arithmetic is checked by default. These checks can be disabled using
unchecked { ... }
. - Code Generator: Cause a panic if a byte array in storage is accessed whose length is encoded incorrectly.
- Code Generator: Use
revert
with error signaturePanic(uint256)
and error codes instead of invalid opcode on failing assertions. - Command Line Interface: JSON fields
abi
,devdoc
,userdoc
andstorage-layout
are now sub-objects rather than strings. - Command Line Interface: Remove the
--old-reporter
option. - Command Line Interface: Remove the legacy
--ast-json
option. Only the--ast-compact-json
option is supported now. - General: Enable ABI coder v2 by default.
- General: Remove global functions
log0
,log1
,log2
,log3
andlog4
. - Parser: Exponentiation is right associative.
a**b**c
is parsed asa**(b**c)
. - Scanner: Remove support for the
\b
,\f
, and\v
escape sequences. - Standard JSON: Remove the
legacyAST
option. - Type Checker: Function call options can only be given once.
- Type System: Declarations with the name
this
,super
and_
are disallowed, with the exception of public functions and events. - Type System: Disallow
msg.data
inreceive()
function. - Type System: Disallow
type(super)
. - Type System: Disallow enums with more than 256 members.
- Type System: Disallow explicit conversions from negative literals and literals larger than
type(uint160).max
toaddress
type. - Type System: Disallow the
byte
type. It was an alias tobytes1
. - Type System: Explicit conversion to
address
type always returns a non-payableaddress
type. In particular,address(u)
,address(b)
,address(c)
andaddress(this)
have the typeaddress
instead ofaddress payable
(Hereu
,b
, andc
are arbitrary variables of typeuint160
,bytes20
and contract type respectively.) - Type System: Explicit conversions between two types are disallowed if it changes more than one of sign, width or kind at the same time.
- Type System: Explicit conversions from literals to enums are only allowed if the value fits in the enum.
- Type System: Explicit conversions from literals to integer type is as strict as implicit conversions.
- Type System: Introduce
address(...).code
to retrieve the code asbytes memory
. The size can be obtained viaaddress(...).code.length
, but it will currently always include copying the code. - Type System: Introduce
block.chainid
for retrieving the current chain id. - Type System: Support
address(...).codehash
to retrieve the codehash of an account. - Type System: The global variables
tx.origin
andmsg.sender
have typeaddress
instead ofaddress payable
. - Type System: Unary negation can only be used on signed integers, not on unsigned integers.
- View Pure Checker: Mark
chainid
as view. - Yul: Disallow the use of reserved identifiers, such as EVM instructions, even if they are not available in the given dialect / EVM version.
- Yul: The
assignimmutable
builtin in the "EVM with objects" dialect takes the base offset of the code to modify as an additional argument.
Language Features:
- Super constructors can now be called using the member notation e.g.
M.C(123)
.
Bugfixes:
- Type Checker: Perform proper truncating integer arithmetic when using constants in array length expressions.
AST Changes:
- New AST Node
IdentifierPath
replacing in many places theUserDefinedTypeName
. - New AST Node
UncheckedBlock
used forunchecked { ... }
.
Language Features:
- Code generator: Support conversion from calldata slices to memory and storage arrays.
- Code generator: Support copying dynamically encoded structs from calldata to memory.
- Code generator: Support copying of nested arrays from calldata to memory.
- Scanner: Generate a parser error when comments or unicode strings contain an unbalanced or underflowing set of unicode direction override markers (LRO, RLO, LRE, RLE, PDF).
- The fallback function can now also have a single
calldata
argument (equalingmsg.data
) and returnbytes memory
(which will not be ABI-encoded but returned as-is). - Wasm backend: Add
i32.select
andi64.select
instructions.
Compiler Features:
- Build System: Optionally support dynamic loading of Z3 and use that mechanism for Linux release builds.
- Code Generator: Avoid memory allocation for default value if it is not used.
- SMTChecker: Apply constant evaluation on binary arithmetic expressions.
- SMTChecker: Create underflow and overflow verification targets for increment/decrement in the CHC engine.
- SMTChecker: Report struct values in counterexamples from CHC engine.
- SMTChecker: Support early returns in the CHC engine.
- SMTChecker: Support getters.
- SMTChecker: Support named arguments in function calls.
- SMTChecker: Support struct constructor.
- Standard-Json: Move the recently introduced
modelCheckerSettings
key tosettings.modelChecker
. - Standard-Json: Properly filter the requested output artifacts.
Bugfixes:
- Code generator: Do not pad empty string literals with a single 32-byte zero field in the ABI coder v1.
- NatSpec: Fix segfault when inheriting return parameter documentation for modifiers with no parameters.
- SMTChecker: Fix cast string literals to byte arrays.
- SMTChecker: Fix internal compiler error when doing bitwise compound assignment with string literals.
- SMTChecker: Fix internal error when trying to generate counterexamples with old z3.
- SMTChecker: Fix segmentation fault that could occur on certain SMT-enabled sources when no SMT solver was available.
- SMTChecker: Fix internal error when
bytes.push()
is used as the LHS of an assignment. - Type Checker:
super
is not available in libraries. - Type Checker: Disallow leading zeroes in sized-types (e.g.
bytes000032
), but allow them to be treated as identifiers. - Yul Optimizer: Fix a bug in NameSimplifier where a new name created by NameSimplifier could also be created by NameDispenser.
- Yul Optimizer: Removed NameSimplifier from optimization steps available to users.
Language Features:
- Ability to select the abi coder using
pragma abicoder v1
andpragma abicoder v2
. - Inline Assembly: Use
.offset
and.length
for calldata variables of dynamic array type to access their calldata offset and length (number of elements). Both of them can also be assigned to. - Immutable variables with literal number values are considered pure.
Compiler Features:
- Assembler: Perform linking in assembly mode when library addresses are provided.
- Command Line Interface: New option
--experimental-via-ir
allows switching compilation process to go through the Yul intermediate representation. This is highly experimental and is used for development purposes. - Command Line Interface: New option
--model-checker-timeout
sets a timeout in milliseconds for each individual query performed by the SMTChecker. - Command Line Interface: Report error if file could not be read in
--standard-json
mode. - Command Line interface: Report proper error for each output file which could not be written. Previously an exception was thrown, and execution aborted, on the first error.
- SMTChecker: Add division by zero checks in the CHC engine.
- SMTChecker: More precise analysis of external calls using
this
. - SMTChecker: Support
selector
for expressions with value known at compile-time. - Standard JSON: New option
modelCheckerSettings.timeout
sets a timeout in milliseconds for each individual query performed by the SMTChecker. - Standard JSON: New option
settings.viaIR
allows the same switch as--experimental-via-ir
on the commandline.
Bugfixes:
- Code generator: Fix missing creation dependency tracking for abstract contracts.
- Command Line Interface: Fix write error when the directory passed to
--output-dir
ends with a slash. - Command Line Interface: Reject duplicate libraries in
--libraries
option instead of arbitrarily choosing one. - NatSpec: Fix internal error when inheriting return parameter documentation but the parameter names differ between base and inherited.
- SMTChecker: Fix CHC false positives when branches are used inside modifiers.
- SMTChecker: Fix false negative in modifier applied multiple times.
- SMTChecker: Fix incorrect counterexamples reported by the CHC engine.
- SMTChecker: Fix internal error in the BMC engine when inherited contract from a different source unit has private state variables.
- SMTChecker: Fix internal error on conversion from string literal to byte.
- SMTChecker: Fix internal error when
array.push()
is used as the LHS of an assignment. - SMTChecker: Fix internal error when assigning state variable via contract's name.
- SMTChecker: Fix internal error when using tuples of rational literals inside the conditional operator.
- SMTChecker: Fix lack of reporting potential violations when using only the CHC engine.
- Standard JSON: Fix library addresses specified in
libraries
being used for linking even if the file names do not match.
AST Changes:
- New member
suffix
for inline assembly identifiers. Currently supported values are"slot"
,"offset"
and"length"
to access the components of a Solidity variable.
Important Bugfixes:
- Code Generator: Fix data corruption bug when copying empty byte arrays from memory or calldata to storage.
Language Features:
- Constants can be defined at file level.
Compiler Features:
- Command Line Interface: New option
--model-checker-engine
allows to choose a specific SMTChecker engine. Options areall
(default),bmc
,chc
andnone
. - Control Flow Graph: Print warning for non-empty functions with unnamed return parameters that are not assigned a value in all code paths.
- SMTChecker: Support
keccak256
,sha256
,ripemd160
andecrecover
in the CHC engine. - SMTChecker: Support inline arrays.
- SMTChecker: Support variables
block
,msg
andtx
in the CHC engine. - Standard JSON: New option
modelCheckerSettings.engine
allows to choose a specific SMTChecker engine. Options areall
(default),bmc
,chc
andnone
.
Bugfixes:
- Code generator: Fix
ABIEncoderV2
pragma from the current module affecting inherited functions and applied modifiers. - Code generator: Fix internal compiler error when referencing members via module name but not using the reference.
- Code generator: Fix internal error on returning structs containing mappings from library function.
- Code generator: Use revert instead of invalid opcode for out-of-bounds array index access in getter.
- Contract Level Checker: Add missing check against inheriting functions with ABIEncoderV2 return types in ABIEncoderV1 contracts.
- Name Resolver: Fix shadowing/same-name warnings for later declarations.
- Type Checker: Allow arrays of contract types as type expressions and as arguments for
abi.decode
. - Type Checker: Disallow invalid use of library names as type name.
- Type Checker: Fix internal compiler error caused by storage parameters with nested mappings in libraries.
Important Bugfixes:
- Code Generator: Properly cleanup after copying dynamic-array to storage for packed types.
Compiler Features:
- Code generator: Implemented events with function type as one of its indexed parameters.
- General: Option to stop compilation after parsing stage. Can be used with
solc --stop-after parsing
- Optimizer: Optimize
exp
when base is-1
. - SMTChecker: Support
addmod
andmulmod
. - SMTChecker: Support array slices.
- SMTChecker: Support type conversions.
Bugfixes:
- Fixed internal compiler errors for certain contracts involving the
new
expression. - JSON AST: Fix internal error when using
--ast-json
on a function with memory arguments in ABIEncoderV2 contracts. - Type Checker: Add missing checks for calls using types incompatible with ABIEncoderV1 in modules where ABIEncoderV2 is not enabled.
- Type Checker: Fix internal compiler error when calling
.push(<arg>)
for a storage array with a nested mapping.
Important Bugfixes:
- Type Checker: Disallow two or more free functions with identical name (potentially imported and aliased) and parameter types.
Compiler Features:
- Export compiler-generated utility sources via standard-json or combined-json.
- Optimizer: Optimize
exp
when base is 0, 1 or 2. - SMTChecker: Keep knowledge about string literals, even through assignment, and thus support the
.length
property properly. - SMTChecker: Support
address
type conversion with literals, e.g.address(0)
. - SMTChecker: Support
revert()
. - SMTChecker: Support
type(T).min
,type(T).max
, andtype(I).interfaceId
. - SMTChecker: Support compound and, or, and xor operators.
- SMTChecker: Support events and low-level logs.
- SMTChecker: Support fixed bytes index access.
- SMTChecker: Support memory allocation, e.g.
new bytes(123)
. - SMTChecker: Support shifts.
- SMTChecker: Support structs.
- Type Checker: Explain why oversized hex string literals can not be explicitly converted to a shorter
bytesNN
type. - Type Checker: More detailed error messages why implicit conversions fail.
- Type Checker: Report position of first invalid UTF-8 sequence in
unicode""
literals. - Yul IR Generator: Report source locations related to unimplemented features.
- Yul Optimizer: Inline into functions further down in the call graph first.
- Yul Optimizer: Prune unused parameters in functions.
- Yul Optimizer: Try to simplify function names.
Bugfixes:
- Code generator: Fix internal error on stripping dynamic types from return parameters on EVM versions without
RETURNDATACOPY
. - Type Checker: Add missing check against nested dynamic arrays in ABI encoding functions when ABIEncoderV2 is disabled.
- Type Checker: Correct the error message for invalid named parameter in a call to refer to the right argument.
- Type Checker: Disallow
virtual
for modifiers in libraries. - Name Resolver: Correct the warning for homonymous, but not shadowing declarations.
- Type system: Fix internal error on implicit conversion of contract instance to the type of its
super
. - Type system: Fix internal error on implicit conversion of string literal to a calldata string.
- Type system: Fix named parameters in overloaded function and event calls being matched incorrectly if the order differs from the declaration.
- ViewPureChecker: Prevent visibility check on constructors.
Language Features:
- Allow function definitions outside of contracts, behaving much like internal library functions.
- Code generator: Implementing copying structs from calldata to storage.
Compiler Features:
- SMTChecker: Add underflow and overflow as verification conditions in the CHC engine.
- SMTChecker: Support bitwise or, xor and not operators.
- SMTChecker: Support conditional operator.
- Standard JSON Interface: Do not run EVM bytecode code generation, if only Yul IR or EWasm output is requested.
- Yul Optimizer: LoopInvariantCodeMotion can move reading operations outside for-loops as long as the affected area is not modified inside the loop.
- Yul: Report error when using non-string literals for
datasize()
,dataoffset()
,linkersymbol()
,loadimmutable()
,setimmutable()
.
Bugfixes:
- AST: Remove
null
member values also when the compiler is used in standard-json-mode. - General: Allow
type(Contract).name
for abstract contracts and interfaces. - Immutables: Disallow assigning immutables more than once during their declaration.
- Immutables: Properly treat complex assignment and increment/decrement as both reading and writing and thus disallow it everywhere for immutable variables.
- Optimizer: Keep side-effects of
x
inbyte(a, shr(b, x))
even if the constantsa
andb
would make the expression zero unconditionally. This optimizer rule is very hard if not impossible to trigger in a way that it can result in invalid code, though. - References Resolver: Fix internal bug when using constructor for library.
- Scanner: Fix bug where whitespace would be allowed within the
->
token (e.g.function f() - > x {}
becomes invalid in inline assembly and Yul). - SMTChecker: Fix internal error in BMC function inlining.
- SMTChecker: Fix internal error on array implicit conversion.
- SMTChecker: Fix internal error on fixed bytes index access.
- SMTChecker: Fix internal error on lvalue unary operators with tuples.
- SMTChecker: Fix internal error on tuple assignment.
- SMTChecker: Fix internal error on tuples of one element that have tuple type.
- SMTChecker: Fix internal error when using imported code.
- SMTChecker: Fix soundness of array
pop
. - Type Checker: Disallow
using for
directive inside interfaces. - Type Checker: Disallow signed literals as exponent in exponentiation operator.
- Type Checker: Disallow structs containing nested mapping in memory as parameters for library functions.
- Yul Optimizer: Ensure that Yul keywords are not mistakenly used by the NameDispenser and VarNameCleaners. The bug would manifest as uncompilable code.
- Yul Optimizer: Make function inlining order more resilient to whether or not unrelated source files are present.
Breaking changes:
- Inline Assembly: Disallow
.
in user-defined function and variable names. - Inline Assembly: Slot and offset of storage pointer variable
x
are accessed viax.slot
andx.offset
instead ofx_slot
andx_offset
. - JSON AST: Mark hex string literals with
kind: "hexString"
. - JSON AST: Remove members with
null
value from JSON output. - Parser: Disallow
gwei
as identifier. - Parser: Disallow dot syntax for
value
andgas
. - Parser: Disallow non-printable characters in string literals.
- Parser: Introduce Unicode string literals:
unicode"😃"
. - Parser: NatSpec comments on variables are only allowed for public state variables.
- Parser: Remove the
finney
andszabo
denominations. - Parser: Remove the identifier
now
(replaced byblock.timestamp
). - Reference Resolver:
using A for B
only affects the contract it is mentioned in and not all derived contracts - Type Checker: Disallow
virtual
for library functions. - Type Checker: Disallow assignments to state variables that contain nested mappings.
- Type checker: Disallow events with same name and parameter types in inheritance hierarchy.
- Type Checker: Disallow shifts by signed types.
- Type Checker: Disallow structs and arrays in memory or calldata if they contain nested mappings.
- Type Checker: Exponentiation and shifts of literals by non-literals will always use
uint256
orint256
as a type. - Yul: Disallow consecutive and trailing dots in identifiers. Leading dots were already disallowed.
- Yul: Disallow EVM instruction
pc()
.
Language Features:
- Inheritance: Allow overrides to have stricter state mutability:
view
can overridenonpayable
andpure
can overrideview
. - Parser: Deprecate visibility for constructors.
- State mutability: Do not issue recommendation for stricter mutability for virtual functions but do issue it for functions that override.
Compiler Features:
- SMTChecker: Report multi-transaction counterexamples including the function calls that initiate the transactions. This does not include concrete values for reference types and reentrant calls.
- Variable declarations using the
var
keyword are not recognized anymore.
Bugfixes:
- Immutables: Fix internal compiler error when immutables are not assigned.
- Inheritance: Disallow public state variables overwriting
pure
functions. - NatSpec: Constructors and functions have consistent userdoc output.
- SMTChecker: Fix internal error when assigning to a 1-tuple.
- SMTChecker: Fix internal error when tuples have extra effectless parenthesis.
- State Mutability: Constant public state variables are considered
pure
functions. - Type Checker: Fixing deduction issues on function types when function call has named arguments.
Language Features:
- NatSpec: Implement tag
@inheritdoc
to copy documentation from a specific base contract. - Wasm backend: Add
i32.ctz
,i64.ctz
,i32.popcnt
, andi64.popcnt
.
Compiler Features:
- Code Generator: Avoid double cleanup when copying to memory.
- Code Generator: Evaluate
keccak256
of string literals at compile-time. - Optimizer: Add rule to remove shifts inside the byte opcode.
- Peephole Optimizer: Add rule to remove swap after dup.
- Peephole Optimizer: Remove unnecessary masking of tags.
- Yul EVM Code Transform: Free stack slots directly after visiting the right-hand-side of variable declarations instead of at the end of the statement only.
Bugfixes:
- SMTChecker: Fix error in events with indices of type static array.
- SMTChecker: Fix internal error in sequential storage array pushes (
push().push()
). - SMTChecker: Fix internal error when using bitwise operators on fixed bytes type.
- SMTChecker: Fix internal error when using compound bitwise operator assignments on array indices inside branches.
- Type Checker: Fix internal compiler error related to oversized types.
- Type Checker: Fix overload resolution in combination with
{value: ...}
.
Build System:
- Update internal dependency of jsoncpp to 1.9.3.
Language Features:
- General: Add unit denomination
gwei
- Yul: Support
linkersymbol
builtin in standalone assembly mode to refer to library addresses. - Yul: Support using string literals exceeding 32 bytes as literal arguments for builtins.
Compiler Features:
- NatSpec: Add fields
kind
andversion
to the JSON output. - NatSpec: Inherit tags from unique base functions if derived function does not provide any.
- Commandline Interface: Prevent some incompatible commandline options from being used together.
- NatSpec: Support NatSpec comments on events.
- Yul Optimizer: Store knowledge about storage / memory after
a := sload(x)
/a := mload(x)
. - SMTChecker: Support external calls to unknown code.
- Source Maps: Also tag jumps into and out of Yul functions as jumps into and out of functions.
Bugfixes:
- NatSpec: Do not consider
////
and/***
as NatSpec comments. - Type Checker: Disallow constructor parameters with
calldata
data location. - Type Checker: Do not disallow assigning to calldata variables.
- Type Checker: Fix internal error related to
using for
applied to non-libraries. - Wasm backend: Fix code generation for for-loops with pre statements.
- Wasm backend: Properly support both
i32.drop
andi64.drop
, and removedrop
. - Yul: Disallow the same variable to occur multiple times on the left-hand side of an assignment.
- Yul: Fix source location of variable multi-assignment.
Important Bugfixes:
- Fixed a bug related to internal library functions with
calldata
parameters called viausing for
.
Compiler Features:
- Commandline Interface: Re-group help screen.
- Output compilation error codes in standard-json and when using
--error-codes
. - Yul: Raise warning for switch statements that only have a default and no other cases.
Bugfixes:
- SMTChecker: Fix internal error when encoding tuples of tuples.
- SMTChecker: Fix aliasing soundness after pushing to an array pointer.
- Type system: Fix internal compiler error on calling externally a function that returns variables with calldata location.
- Type system: Fix bug where a bound function was not found if
using for
is applied to explicit reference types.
Language Features:
- Permit calldata location for all variables.
- NatSpec: Support NatSpec comments on state variables.
- Yul: EVM instruction
pc()
is marked deprecated and will be removed in the next breaking release.
Compiler Features:
- Build system: Update the soljson.js build to emscripten 1.39.15 and boost 1.73.0 and include Z3 for integrated SMTChecker support without the callback mechanism.
- Build system: Switch the emscripten build from the fastcomp backend to the upstream backend.
- Code Generator: Do not introduce new internal source references for small compiler routines.
- Commandline Interface: Adds new option
--base-path PATH
to use the given path as the root of the source tree (defaults to the root of the filesystem). - SMTChecker: Support array
length
. - SMTChecker: Support array
push
andpop
. - SMTChecker: General support to BitVectors and the bitwise
and
operator.
Bugfixes:
- Code Generator: Trigger proper unimplemented errors on certain array copy operations.
- Commandline Interface: Fix internal error when using
--assemble
or--yul
options with--machine ewasm
but without specifying--yul-dialect
. - NatSpec: DocString block is terminated when encountering an empty line.
- Optimizer: Fixed a bug in BlockDeDuplicator.
- Scanner: Fix bug when two empty NatSpec comments lead to scanning past EOL.
- SMTChecker: Fix internal error on try/catch clauses with parameters.
- SMTChecker: Fix internal error when applying arithmetic operators to fixed point variables.
- SMTChecker: Fix internal error when assigning to index access inside branches.
- SMTChecker: Fix internal error when short circuiting Boolean expressions with function calls in state variable initialization.
- Type Checker: Disallow assignments to storage variables of type
mapping
. - Type Checker: Disallow inline arrays of non-nameable types.
- Type Checker: Disallow usage of override with non-public state variables.
- Type Checker: Fix internal compiler error when accessing members of array slices.
- Type Checker: Fix internal compiler error when forward referencing non-literal constants from inline assembly.
- Type Checker: Fix internal compiler error when trying to decode too large static arrays.
- Type Checker: Fix wrong compiler error when referencing an overridden function without calling it.
Important Bugfixes:
- Add missing callvalue check to the creation code of a contract that does not define a constructor but has a base that does define a constructor.
- Disallow array slices of arrays with dynamically encoded base types.
- String literals containing backslash characters can no longer cause incorrect code to be generated when passed directly to function calls or encoding functions when ABIEncoderV2 is active.
Language Features:
- Implemented
type(T).min
andtype(T).max
for every integer typeT
that returns the smallest and largest value representable by the type.
Compiler Features:
- Commandline Interface: Don't ignore
--yul-optimizations
in assembly mode. - Allow using abi encoding functions for calldata array slices without explicit casts.
- Wasm binary output: Implement
br
andbr_if
.
Bugfixes:
- ABI: Skip
private
orinternal
constructors. - Fixed an "Assembly Exception in Bytecode" error where requested functions were generated twice.
- Natspec: Fixed a bug that ignored
@return
tag when no other developer-documentation tags were present. - Type Checker: Checks if a literal exponent in the
**
operation is too large or fractional. - Type Checker: Disallow accessing
runtimeCode
for contract types that contain immutable state variables. - Yul Assembler: Fix source location of variable declarations without value.
Language Features:
- Add support for EIP 165 interface identifiers with
type(I).interfaceId
. - Allow virtual modifiers inside abstract contracts to have empty body.
Compiler Features:
- Optimizer: Simplify repeated AND and OR operations.
- Standard Json Input: Support the prefix
file://
in the fieldurls
. - Add option to specify optimization steps to be performed by Yul optimizer with
--yul-optimizations
in the commandline interface oroptimizer.details.yulDetails.optimizerSteps
in standard-json.
Bugfixes:
- SMTChecker: Fix internal error when fixed points are used.
- SMTChecker: Fix internal error when using array slices.
- Type Checker: Disallow
virtual
andoverride
for constructors. - Type Checker: Fix several internal errors by performing size and recursiveness checks of types before the full type checking.
- Type Checker: Fix internal error when assigning to empty tuples.
- Type Checker: Fix internal error when applying unary operators to tuples with empty components.
- Type Checker: Perform recursiveness check on structs declared at the file level.
Build System:
- soltest.sh:
SOLIDITY_BUILD_DIR
is no longer relative toREPO_ROOT
to allow for build directories outside of the source tree.
Important Bugfixes:
- Fix tuple assignments with components occupying multiple stack slots and different stack size on left- and right-hand-side.
Bugfixes:
- AST export: Export
immutable
property in the fieldmutability
. - SMTChecker: Fix internal error in the CHC engine when calling inherited functions internally.
- Type Checker: Error when trying to encode functions with call options gas and value set.
Important Bugfixes:
- Code Generator: Restrict the length of dynamic memory arrays to 64 bits during creation at runtime fixing a possible overflow.
Language Features:
- Allow local storage variables to be declared without initialization, as long as they are assigned before they are accessed.
- State variables can be marked
immutable
which causes them to be read-only, but assignable in the constructor. The value will be stored directly in the code.
Compiler Features:
- Commandline Interface: Enable output of storage layout with
--storage-layout
. - Metadata: Added support for IPFS hashes of large files that need to be split in multiple chunks.
Bugfixes:
- Inheritance: Allow public state variables to override functions with dynamic memory types in their return values.
- Inline Assembly: Fix internal error when accessing invalid constant variables.
- Inline Assembly: Fix internal error when accessing functions.
- JSON AST: Always add pointer suffix for memory reference types.
- Reference Resolver: Fix internal error when accessing invalid struct members.
- Type Checker: Fix internal errors when assigning nested tuples.
Language Features:
- General: Deprecated
value(...)
andgas(...)
in favor of{value: ...}
and{gas: ...}
- Inline Assembly: Allow assigning to
_slot
of local storage variable pointers. - Inline Assembly: Perform control flow analysis on inline assembly. Allows storage returns to be set in assembly only.
Compiler Features:
- AssemblyStack: Support for source locations (source mappings) and thus debugging Yul sources.
- Commandline Interface: Enable output of experimental optimized IR via
--ir-optimized
.
Bugfixes:
- Inheritance: Fix incorrect error on calling unimplemented base functions.
- Reference Resolver: Fix scoping issue following try/catch statements.
- Standard-JSON-Interface: Fix a bug related to empty filenames and imports.
- SMTChecker: Fix internal errors when analysing tuples.
- Yul AST Import: correctly import blocks as statements, switch statements and string literals.
Language Features:
- Allow contract types and enums as keys for mappings.
- Allow function selectors to be used as compile-time constants.
- Report source locations for structured documentation errors.
Compiler Features:
- AST: Add a new node for doxygen-style, structured documentation that can be received by contract, function, event and modifier definitions.
- Code Generator: Use
calldatacopy
instead ofcodecopy
to zero out memory past input. - Debug: Provide reason strings for compiler-generated internal reverts when using the
--revert-strings
option or thesettings.debug.revertStrings
setting ondebug
mode. - Yul Optimizer: Prune functions that call each other but are otherwise unreferenced.
- SMTChecker: CHC support to internal function calls.
Bugfixes:
- Assembly: Added missing
source
field to legacy assembly json output to complete the source reference. - Parser: Fix an internal error for
abstract
withoutcontract
. - Type Checker: Make invalid calls to uncallable types fatal errors instead of regular.
Language Features:
- Allow accessing external functions via contract and interface names to obtain their selector.
- Allow interfaces to inherit from other interfaces
- Allow gas and value to be set in external function calls using
c.f{gas: 10000, value: 4 ether}()
. - Allow specifying the
salt
for contract creations and thus thecreate2
opcode usingnew C{salt: 0x1234, value: 1 ether}(arg1, arg2)
. - Inline Assembly: Support literals
true
andfalse
.
Compiler Features:
- LLL: The LLL compiler has been removed.
- General: Raise warning if runtime bytecode exceeds 24576 bytes (a limit introduced in Spurious Dragon).
- General: Support compiling starting from an imported AST. Among others, this can be used for mutation testing.
- Yul Optimizer: Apply penalty when trying to rematerialize into loops.
Bugfixes:
- Commandline interface: Only activate yul optimizer if
--optimize
is given. - Fixes internal compiler error on explicitly calling unimplemented base functions.
Build System:
- Switch to building soljson.js with an embedded base64-encoded wasm binary.
Bugfixes:
- Yul Optimizer: Fix bug in redundant assignment remover in combination with break and continue statements.
Breaking changes:
- ABI: Remove the deprecated
constant
andpayable
fields. - ABI: The
type
field is now required and no longer specified to default tofunction
. - AST: Inline assembly is exported as structured JSON instead of plain string.
- C API (
libsolc
): Introduce context parameter to bothsolidity_compile
and the callback. - C API (
libsolc
): The provided callback now takes two parameters, kind and data. The callback can then be used for multiple purposes, such has file imports and SMT queries. - C API (
libsolc
):solidity_free
was renamed tosolidity_reset
. Functionssolidity_alloc
andsolidity_free
were added. - C API (
libsolc
):solidity_compile
now returns a string that must be explicitly freed viasolidity_free()
- Commandline Interface: Remove the text-based AST printer (
--ast
). - Commandline Interface: Switch to the new error reporter by default.
--old-reporter
falls back to the deprecated old error reporter. - Commandline Interface: Add option to disable or choose hash method between IPFS and Swarm for the bytecode metadata.
- General: Disallow explicit conversions from external function types to
address
and add a member calledaddress
to them as replacement. - General: Enable Yul optimizer as part of standard optimization.
- General: New reserved keywords:
override
,receive
, andvirtual
. - General:
private
cannot be used together withvirtual
. - General: Split unnamed fallback functions into two cases defined using
fallback()
andreceive()
. - Inheritance: State variable shadowing is now disallowed.
- Inline Assembly: Only strict inline assembly is allowed.
- Inline Assembly: Variable declarations cannot shadow declarations outside the assembly block.
- JSON AST: Replace
superFunction
attribute bybaseFunctions
. - Natspec JSON Interface: Properly support multiple
@return
statements in@dev
documentation and enforce named return parameters to be mentioned documentation. - Source mappings: Add "modifier depth" as a fifth field in the source mappings.
- Standard JSON Interface: Add option to disable or choose hash method between IPFS and Swarm for the bytecode metadata.
- Syntax:
push(element)
for dynamic storage arrays do not return the new length anymore. - Syntax: Abstract contracts need to be marked explicitly as abstract by using the
abstract
keyword. - Syntax:
length
member of arrays is now always read-only, even for storage arrays. - Type Checker: Resulting type of exponentiation is equal to the type of the base. Also allow signed types for the base.
Language Features:
- Allow explicit conversions from
address
toaddress payable
viapayable(...)
. - Allow global enums and structs.
- Allow public variables to override external functions.
- Allow underscores as delimiters in hex strings.
- Allow to react on failing external calls using
try
andcatch
. - Introduce syntax for array slices and implement them for dynamic calldata arrays.
- Introduce
push()
for dynamic storage arrays. It returns a reference to the newly allocated element, if applicable. - Introduce
virtual
andoverride
keywords. - Modify
push(element)
for dynamic storage arrays such that it does not return the new length anymore. - Yul: Introduce
leave
statement that exits the current function. - JSON AST: Add the function selector of each externally-visible FunctonDefinition to the AST JSON export.
Compiler Features:
- Allow revert strings to be stripped from the binary using the
--revert-strings
option or thesettings.debug.revertStrings
setting. - ABIEncoderV2: Do not warn about enabled ABIEncoderV2 anymore (the pragma is still needed, though).
Bugfixes:
- Type Checker: Disallow overriding of private functions.
Backported Bugfixes:
- Yul Optimizer: Fix bug in redundant assignment remover in combination with break and continue statements.
Bugfixes:
- Yul Optimizer: Fix incorrect redundant load optimization crossing user-defined functions that contain for-loops with memory / storage writes.
Language Features:
- Allow to obtain the selector of public or external library functions via a member
.selector
. - Inline Assembly: Support constants that reference other constants.
- Parser: Allow splitting hexadecimal and regular string literals into multiple parts.
Compiler Features:
- Commandline Interface: Allow translation from yul / strict assembly to EWasm using
solc --yul --yul-dialect evm --machine ewasm
- Set the default EVM version to "Istanbul".
- SMTChecker: Add support to constructors including constructor inheritance.
- Yul: When compiling via Yul, string literals from the Solidity code are kept as string literals if every character is safely printable.
- Yul Optimizer: Perform loop-invariant code motion.
Bugfixes:
- SMTChecker: Fix internal error when using
abi.decode
. - SMTChecker: Fix internal error when using arrays or mappings of functions.
- SMTChecker: Fix internal error in array of structs type.
- Version Checker:
^0
should match0.5.0
, but no prerelease. - Yul: Consider infinite loops and recursion to be not removable.
Build System:
- Update to emscripten version 1.39.3.
Language Features:
- Allow to obtain the address of a linked library with
address(LibraryName)
.
Compiler Features:
- Code Generator: Use SELFBALANCE opcode for
address(this).balance
if using Istanbul EVM. - EWasm: Experimental EWasm binary output via
--ewasm
and as documented in standard-json. - SMTChecker: Add break/continue support to the CHC engine.
- SMTChecker: Support assignments to multi-dimensional arrays and mappings.
- SMTChecker: Support inheritance and function overriding.
- Standard JSON Interface: Output the storage layout of a contract when artifact
storageLayout
is requested. - TypeChecker: List possible candidates when overload resolution fails.
- TypeChecker: Disallow variables of library types.
Bugfixes:
- Code Generator: Fixed a faulty assert that would wrongly trigger for array sizes exceeding unsigned integer.
- SMTChecker: Fix internal error when accessing indices of fixed bytes.
- SMTChecker: Fix internal error when using function pointers as arguments.
- SMTChecker: Fix internal error when implicitly converting string literals to fixed bytes.
- Type Checker: Disallow constructor of the same class to be used as modifier.
- Type Checker: Treat magic variables as unknown identifiers in inline assembly.
- Code Generator: Fix internal error when trying to convert
super
to a different type
Language Features:
- Type Checker: Allow assignment to external function arguments except for reference types.
Compiler Features:
- ABI Output: Change sorting order of functions from selector to kind, name.
- Optimizer: Add rule that replaces the BYTE opcode by 0 if the first argument is larger than 31.
- SMTChecker: Add loop support to the CHC engine.
- Yul Optimizer: Take side-effect-freeness of user-defined functions into account.
- Yul Optimizer: Remove redundant mload/sload operations.
- Yul Optimizer: Use the fact that branch conditions have certain value inside the branch.
Bugfixes:
- Code Generator: Fix internal error when popping a dynamic storage array of mappings.
- Name Resolver: Fix wrong source location when warning on shadowed aliases in import declarations.
- Scanner: Fix multi-line natspec comment parsing with triple slashes when file is encoded with CRLF instead of LF.
- Type System: Fix arrays of recursive structs.
- Yul Optimizer: Fix reordering bug in connection with shifted one and mul/div-instructions in for loop conditions.
Language Features:
- Inline Assembly: Support direct constants of value type in inline assembly.
Compiler Features:
- ABI: Additional internal type info in the field
internalType
. - eWasm: Highly experimental eWasm output using
--ewasm
in the commandline interface or output selection ofewasm.wast
in standard-json. - Metadata: Update the swarm hash to the current specification, changes
bzzr0
tobzzr1
and urls to usebzz-raw://
. - Standard JSON Interface: Compile only selected sources and contracts.
- Standard JSON Interface: Provide secondary error locations (e.g. the source position of other conflicting declarations).
- SMTChecker: Do not erase knowledge about storage pointers if another storage pointer is assigned.
- SMTChecker: Support string literal type.
- SMTChecker: New Horn-based algorithm that proves assertions via multi-transaction contract invariants.
- Standard JSON Interface: Provide AST even on errors if
--error-recovery
commandline switch or StandardCompilersettings.parserErrorRecovery
is true. - Yul Optimizer: Do not inline function if it would result in expressions being duplicated that are not cheap.
Bugfixes:
- ABI decoder: Ensure that decoded arrays always point to distinct memory locations.
- Code Generator: Treat dynamically encoded but statically sized arrays and structs in calldata properly.
- SMTChecker: Fix internal error when inlining functions that contain tuple expressions.
- SMTChecker: Fix pointer knowledge erasing in loops.
- SMTChecker: Fix internal error when using compound bitwise assignment operators inside branches.
- SMTChecker: Fix internal error when inlining a function that returns a tuple containing an unsupported type inside a branch.
- SMTChecker: Fix internal error when inlining functions that use state variables and belong to a different source.
- SMTChecker: Fix internal error when reporting counterexamples concerning state variables from different source files.
- SMTChecker: Fix SMT sort mismatch when using string literals.
- View/Pure Checker: Properly detect state variable access through base class.
- Yul Analyzer: Check availability of data objects already in analysis phase.
- Yul Optimizer: Fix an issue where memory-accessing code was removed even though
msize
was used in the program.
Important Bugfixes:
- ABIEncoderV2: Fix incorrect abi encoding of storage array of data type that occupy multiple storage slots
- Code Generator: Properly zero out higher order bits in elements of an array of negative numbers when assigning to storage and converting the type at the same time.
Compiler Features:
- Commandline Interface: Experimental parser error recovery via the
--error-recovery
commandline switch or StandardCompilersettings.parserErrorRecovery
boolean. - Optimizer: Add rule to simplify
SUB(~0, X)
toNOT(X)
. - Yul Optimizer: Make the optimizer work for all dialects of Yul including eWasm.
Bugfixes:
- Type Checker: Set state mutability of the function type members
gas
andvalue
to pure (while their return type inherits state mutability from the function type). - Yul / Inline Assembly Parser: Disallow trailing commas in function call arguments.
Build System:
- Attempt to use stock Z3 cmake files to find Z3 and only fall back to manual discovery.
- CMake: use imported targets for boost.
- Emscripten build: upgrade to boost 1.70.
- Generate a cmake error for gcc versions older than 5.0.
Language Features:
- Inline Assembly: Revert change introduced in 0.5.7: The
callvalue()
instruction does not requirepayable
anymore. - Static Analyzer: Disallow libraries calling themselves externally.
Compiler Features:
- Assembler: Encode the compiler version in the deployed bytecode.
- Code Generator: Fix handling of structs of dynamic size as constructor parameters.
- Inline Assembly: Disallow the combination of
msize()
and the Yul optimizer. - Metadata: Add IPFS hashes of source files.
- Optimizer: Add rule to simplify SHL/SHR combinations.
- Optimizer: Add rules for multiplication and division by left-shifted one.
- SMTChecker: Support inherited state variables.
- SMTChecker: Support tuples and function calls with multiple return values.
- SMTChecker: Support
delete
. - SMTChecker: Inline external function calls to
this
. - Yul Optimizer: Simplify single-run
for
loops toif
statements. - Yul Optimizer: Optimize representation of numbers.
- Yul Optimizer: Do not inline recursive functions.
- Yul Optimizer: Do not remove instructions that affect
msize()
ifmsize()
is used.
Bugfixes:
- Code Generator: Explicitly turn uninitialized internal function pointers into invalid functions when loaded from storage.
- Code Generator: Fix assertion failure when assigning structs containing array of mapping.
- Compiler Internals: Reset the Yul string repository before each compilation, freeing up memory.
- SMTChecker: Fix bad cast in base constructor modifier.
- SMTChecker: Fix internal error when visiting state variable inherited from base class.
- SMTChecker: Fix internal error in fixed point operations.
- SMTChecker: Fix internal error in assignment to unsupported type.
- SMTChecker: Fix internal error in branching when inlining function calls that modify local variables.
Important Bugfixes:
- Code Generator: Fix initialization routine of uninitialized internal function pointers in constructor context.
- Yul Optimizer: Fix SSA transform for multi-assignments.
Language Features:
- ABIEncoderV2: Implement encoding of calldata arrays and structs.
- Code Generation: Implement copying recursive structs from storage to memory.
- Yul: Disallow function definitions inside for-loop init blocks.
Compiler Features:
- ABI Decoder: Raise a runtime error on dirty inputs when using the experimental decoder.
- Optimizer: Add rule for shifts by constants larger than 255 for Constantinople.
- Optimizer: Add rule to simplify certain ANDs and SHL combinations
- SMTChecker: Support arithmetic compound assignment operators.
- SMTChecker: Support unary increment and decrement for array and mapping access.
- SMTChecker: Show unsupported warning for inline assembly blocks.
- SMTChecker: Support mod.
- SMTChecker: Support
contract
type. - SMTChecker: Support
this
as address. - SMTChecker: Support address members.
- Standard JSON Interface: Metadata settings now re-produce the original
"useLiteralContent"
setting from the compilation input. - Yul: Adds break and continue keywords to for-loop syntax.
- Yul: Support
.
as part of identifiers. - Yul Optimizer: Adds steps for detecting and removing of dead code.
- Yul Code Generator: Directly jump over a series of function definitions (instead of jumping over each one)
Bugfixes:
- SMTChecker: Implement Boolean short-circuiting.
- SMTChecker: SSA control-flow did not take into account state variables that were modified inside inlined functions that were called inside branches.
- Type System: Use correct type name for contracts in event parameters when used in libraries. This affected code generation.
- Type System: Allow direct call to base class functions that have overloads.
- Type System: Warn about shadowing builtin variables if user variables are named
this
orsuper
. - Yul: Properly register functions and disallow shadowing between function variables and variables in the outside scope.
Build System:
- Soltest: Add commandline option
--test
/-t
to isoltest which takes a string that allows filtering unit tests. - soltest.sh: allow environment variable
SOLIDITY_BUILD_DIR
to specify build folder and add--help
usage.
Important Bugfixes:
- ABIEncoderV2: Fix bugs related to loading short value types from storage when encoding an array or struct from storage.
- ABIEncoderV2: Fix buffer overflow problem when encoding packed array from storage.
- Optimizer: Fix wrong ordering of arguments in byte optimization rule for constants.
Language Features:
- Function calls with named arguments now work with overloaded functions.
Compiler Features:
- Inline Assembly: Issue error when using
callvalue()
inside nonpayable function (in the same way thatmsg.value
already does). - Standard JSON Interface: Support "Yul" as input language.
- SMTChecker: Show callstack together with model if applicable.
- SMTChecker: Support modifiers.
- Yul Optimizer: Enable stack allocation optimization by default if Yul optimizer is active (disable in
yulDetails
).
Bugfixes:
- Code Generator: Defensively pad memory for
type(Contract).name
to multiples of 32. - Type System: Detect and disallow internal function pointers as parameters for public/external library functions, even when they are nested/wrapped in structs, arrays or other types.
- Yul Optimizer: Properly determine whether a variable can be eliminated during stack compression pass.
- Yul / Inline Assembly Parser: Disallow more than one case statement with the same label inside a switch based on the label's integer value.
Build System:
- Install scripts: Fix boost repository URL for CentOS 6.
- Soltest: Fix hex string update in soltest.
Important Bugfixes:
- Yul Optimizer: Fix visitation order bug for the structural simplifier.
- Optimizer: Fix overflow in optimization rule that simplifies double shift by constant.
Language Features:
- Allow calldata arrays with dynamically encoded base types with ABIEncoderV2.
- Allow dynamically encoded calldata structs with ABIEncoderV2.
Compiler Features:
- Optimizer: Add rules for
lt
-comparisons with constants. - Peephole Optimizer: Remove double
iszero
beforejumpi
. - SMTChecker: Support enums without typecast.
- SMTChecker: Support one-dimensional arrays.
- Type Checker: Provide better error messages for some literal conversions.
- Yul Optimizer: Add rule to remove empty default switch cases.
- Yul Optimizer: Add rule to remove empty cases if no default exists.
- Yul Optimizer: Add rule to replace a switch with no cases with
pop(expression)
.
Bugfixes:
- JSON ABI: Json description of library ABIs no longer contains functions with internal types like storage structs.
- SMTChecker: Fix internal compiler error when contract contains too large rational number.
- Type system: Detect if a contract's base uses types that require the experimental abi encoder while the contract still uses the old encoder.
Build System:
- Soltest: Add support for arrays in function signatures.
- Soltest: Add support for struct arrays in function signatures.
- Soltest: Add support for left-aligned, unpadded hex string literals.
Language Features:
- Add support for getters of mappings with
string
orbytes
key types. - Meta programming: Provide access to the name of contracts via
type(C).name
.
Compiler Features:
- Support
petersburg
asevmVersion
and set as default. - Commandline Interface: Option to activate the experimental yul optimizer using
-optimize-yul
. - Inline Assembly: Consider
extcodehash
as part of Constantinople. - Inline Assembly: Instructions unavailable to the currently configured EVM are errors now.
- SMTChecker: Do not report underflow/overflow if they always revert. This removes false positives when using
SafeMath
. - Standard JSON Interface: Allow retrieving metadata without triggering bytecode generation.
- Standard JSON Interface: Provide fine-grained control over the optimizer via the settings.
- Static Analyzer: Warn about expressions with custom types when they have no effect.
- Optimizer: Add new rules with constants including
LT
,GT
,AND
andBYTE
. - Optimizer: Add rule for shifts with constants for Constantinople.
- Optimizer: Combine multiple shifts with constant shift-by values into one.
- Optimizer: Do not mask with 160-bits after
CREATE
andCREATE2
as they are guaranteed to return an address or 0. - Optimizer: Support shifts in the constant optimiser for Constantinople.
- Yul Optimizer: Add rule to replace switch statements with literals by matching case body.
Bugfixes:
- ABIEncoderV2: Fix internal error related to bare delegatecall.
- ABIEncoderV2: Fix internal error related to ecrecover.
- ABIEncoderV2: Fix internal error related to mappings as library parameters.
- ABIEncoderV2: Fix invalid signature for events containing structs emitted in libraries.
- Inline Assembly: Proper error message for missing variables.
- Optimizer: Fix internal error related to unused tag removal across assemblies. This never generated any invalid code.
- SMTChecker: Fix crash related to statically-sized arrays.
- TypeChecker: Fix internal error and disallow index access on contracts and libraries.
- Yul: Properly detect name clashes with functions before their declaration.
- Yul: Take built-in functions into account in the compilability checker.
- Yul Optimizer: Properly take reassignments to variables in sub-expressions into account when replacing in the ExpressionSimplifier.
Build System:
- Soltest: Add support for left-aligned, padded hex literals.
- Soltest: Add support for right-aligned, padded boolean literals.
Language Features:
- Allow calldata structs without dynamically encoded members with ABIEncoderV2.
Compiler Features:
- ABIEncoderV2: Implement packed encoding.
- C API (
libsolc
/ rawsoljson.js
): Introducesolidity_free
method which releases all internal buffers to save memory. - Commandline Interface: Adds new option
--new-reporter
for improved diagnostics formatting along with--color
and--no-color
for colorized output to be forced (or explicitly disabled).
Bugfixes:
- Code Generator: Defensively pad allocation of creationCode and runtimeCode to multiples of 32 bytes.
- Commandline Interface: Allow yul optimizer only for strict assembly.
- Parser: Disallow empty import statements.
- Type Checker: Disallow mappings with data locations other than
storage
. - Type Checker: Fix internal error when a struct array index does not fit into a uint256.
- Type System: Properly report packed encoded size for arrays and structs (mostly unused until now).
Build System:
- Add support for continuous fuzzing via Google oss-fuzz
- SMT: If using Z3, require version 4.6.0 or newer.
- Soltest: Add parser that is used in the file-based unit test environment.
- Ubuntu PPA Packages: Use CVC4 as SMT solver instead of Z3
Language Features:
- Provide access to creation and runtime code of contracts via
type(C).creationCode
/type(C).runtimeCode
.
Compiler Features:
- Control Flow Graph: Warn about unreachable code.
- SMTChecker: Support basic typecasts without truncation.
- SMTChecker: Support external function calls and erase all knowledge regarding storage variables and references.
Bugfixes:
- Emscripten: Split simplification rule initialization up further to work around issues with soljson.js in some browsers.
- Type Checker: Disallow calldata structs until implemented.
- Type Checker: Return type error if fixed point encoding is attempted instead of throwing
UnimplementedFeatureError
. - Yul: Check that arguments to
dataoffset
anddatasize
are literals at parse time and properly take this into account in the optimizer. - Yul: Parse number literals for detecting duplicate switch cases.
- Yul: Require switch cases to have the same type.
Build System:
- Emscripten: Upgrade to emscripten 1.38.8 on travis and circleci.
Language Features:
- Control Flow Graph: Detect every access to uninitialized storage pointers.
Compiler Features:
- Inline Assembly: Improve error messages around invalid function argument count.
- Code Generator: Only check callvalue once if all functions are non-payable.
- Code Generator: Use codecopy for string constants more aggressively.
- Code Generator: Use binary search for dispatch function if more efficient. The size/speed tradeoff can be tuned using
--optimize-runs
. - SMTChecker: Support mathematical and cryptographic functions in an uninterpreted way.
- SMTChecker: Support one-dimensional mappings.
- Standard JSON Interface: Disallow unknown keys in standard JSON input.
- Standard JSON Interface: Only run code generation if it has been requested. This could lead to unsupported feature errors only being reported at the point where you request bytecode.
- Static Analyzer: Do not warn about unused variables or state mutability for functions with an empty body.
- Type Checker: Add an additional reason to be displayed when type conversion fails.
- Yul: Support object access via
datasize
,dataoffset
anddatacopy
in standalone assembly mode.
Bugfixes:
- Standard JSON Interface: Report specific error message for json input errors instead of internal compiler error.
Build System:
- Replace the trusty PPA build by a static build on cosmic that is used for the trusty package instead.
- Remove support for Visual Studio 2015.
Language Features:
- Allow mapping type for parameters and return variables of public and external library functions.
- Allow public functions to override external functions.
Compiler Features:
- Code generator: Do not perform redundant double cleanup on unsigned integers when loading from calldata.
- Commandline interface: Experimental
--optimize
option for assembly mode (--strict-assembly
and--yul
). - SMTChecker: SMTLib2 queries and responses passed via standard JSON compiler interface.
- SMTChecker: Support
msg
,tx
andblock
member variables. - SMTChecker: Support
gasleft()
andblockhash()
functions. - SMTChecker: Support internal bound function calls.
- Yul: Support Yul objects in
--assemble
,--strict-assembly
and--yul
commandline options.
Bugfixes:
- Assembly output: Do not mix in/out jump annotations with arguments.
- Commandline interface: Fix crash when using
--ast
on empty runtime code. - Code Generator: Annotate jump from calldata decoder to function as "jump in".
- Code Generator: Fix internal error related to state variables of function type access via base contract name.
- Optimizer: Fix nondeterminism bug related to the boost version and constants representation. The bug only resulted in less optimal but still correct code because the generated routine is always verified to be correct.
- Type Checker: Properly detect different return types when overriding an external interface function with a public contract function.
- Type Checker: Disallow struct return types for getters of public state variables unless the new ABI encoder is active.
- Type Checker: Fix internal compiler error when a field of a struct used as a parameter in a function type has a non-existent type.
- Type Checker: Disallow functions
sha3
andsuicide
also without a function call. - Type Checker: Fix internal compiler error with
super
when base contract function is not implemented. - Type Checker: Fixed internal error when trying to create abstract contract in some cases.
- Type Checker: Fixed internal error related to double declaration of events.
- Type Checker: Disallow inline arrays of mapping type.
- Type Checker: Consider abstract function to be implemented by public state variable.
Build System:
- CMake: LLL is not built anymore by default. Must configure it with CMake as
-DLLL=ON
. - Docker: Includes both Scratch and Alpine images.
- Emscripten: Upgrade to Emscripten SDK 1.37.21 and boost 1.67.
Solc-Js:
- Fix handling of standard-json in the commandline executable.
- Remove support of nodejs 4.
How to update your code:
- Change every
.call()
to a.call("")
and every.call(signature, a, b, c)
to use.call(abi.encodeWithSignature(signature, a, b, c))
(the last one only works for value types). - Change every
keccak256(a, b, c)
tokeccak256(abi.encodePacked(a, b, c))
. - Add
public
to every function andexternal
to every fallback or interface function that does not specify its visibility already. - Make your fallback functions
external
. - Explicitly state the data location for all variables of struct, array or mapping types (including function parameters), e.g. change
uint[] x = m_x
touint[] storage x = m_x
. Note thatexternal
functions require parameters with a data location ofcalldata
. - Explicitly convert values of contract type to addresses before using an
address
member. Example: ifc
is a contract, changec.transfer(...)
toaddress(c).transfer(...)
. - Declare variables and especially function arguments as
address payable
, if you want to calltransfer
on them.
Breaking Changes:
- ABI Encoder: Properly pad data from calldata (
msg.data
and external function parameters). Useabi.encodePacked
for unpadded encoding. - C API (
libsolc
/ rawsoljson.js
): Removed theversion
,license
,compileSingle
,compileJSON
,compileJSONCallback
methods and replaced them with thesolidity_license
,solidity_version
andsolidity_compile
methods. - Code Generator: Signed right shift uses proper arithmetic shift, i.e. rounding towards negative infinity. Warning: this may silently change the semantics of existing code!
- Code Generator: Revert at runtime if calldata is too short or points out of bounds. This is done inside the
ABI decoder
and therefore also applies toabi.decode()
. - Code Generator: Use
STATICCALL
forpure
andview
functions. This was already the case in the experimental 0.5.0 mode. - Commandline interface: Remove obsolete
--formal
option. - Commandline interface: Rename the
--julia
option to--yul
. - Commandline interface: Require
-
if standard input is used as source. - Commandline interface: Use hash of library name for link placeholder instead of name itself.
- Compiler interface: Disallow remappings with empty prefix.
- Control Flow Analyzer: Consider mappings as well when checking for uninitialized return values.
- Control Flow Analyzer: Turn warning about returning uninitialized storage pointers into an error.
- General:
continue
in ado...while
loop jumps to the condition (it used to jump to the loop body). Warning: this may silently change the semantics of existing code. - General: Disallow declaring empty structs.
- General: Disallow raw
callcode
(was already deprecated in 0.4.12). It is still possible to use it via inline assembly. - General: Disallow
var
keyword. - General: Disallow
sha3
andsuicide
aliases. - General: Disallow the
throw
statement. This was already the case in the experimental 0.5.0 mode. - General: Disallow the
years
unit denomination (was already deprecated in 0.4.24) - General: Introduce
emit
as a keyword instead of parsing it as identifier. - General: New keywords:
calldata
andconstructor
- General: New reserved keywords:
alias
,apply
,auto
,copyof
,define
,immutable
,implements
,macro
,mutable
,override
,partial
,promise
,reference
,sealed
,sizeof
,supports
,typedef
andunchecked
. - General: Remove assembly instruction aliases
sha3
andsuicide
- General: C99-style scoping rules are enforced now. This was already the case in the experimental 0.5.0 mode.
- General: Disallow combining hex numbers with unit denominations (e.g.
0x1e wei
). This was already the case in the experimental 0.5.0 mode. - JSON AST: Remove
constant
andpayable
fields (the information is encoded in thestateMutability
field). - JSON AST: Replace the
isConstructor
field by a newkind
field, which can beconstructor
,fallback
orfunction
. - Interface: Remove "clone contract" feature. The
--clone-bin
and--combined-json clone-bin
commandline options are not available anymore. - Name Resolver: Do not exclude public state variables when looking for conflicting declarations.
- Optimizer: Remove the no-op
PUSH1 0 NOT AND
sequence. - Parser: Disallow trailing dots that are not followed by a number.
- Parser: Remove
constant
as function state mutability modifier. - Parser: Disallow uppercase X in hex number literals
- Type Checker: Disallow assignments between tuples with different numbers of components. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow values for constants that are not compile-time constants. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow arithmetic operations for boolean variables.
- Type Checker: Disallow tight packing of literals. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow calling base constructors without parentheses. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow conversions between
bytesX
anduintY
of different size. - Type Checker: Disallow conversions between unrelated contract types. Explicit conversion via
address
can still achieve it. - Type Checker: Disallow empty return statements for functions with one or more return values.
- Type Checker: Disallow empty tuple components. This was partly already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow multi-variable declarations with mismatching number of values. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow specifying base constructor arguments multiple times in the same inheritance hierarchy. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow calling constructor with wrong argument count. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Disallow uninitialized storage variables. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Detecting cyclic dependencies in variables and structs is limited in recursion to 256.
- Type Checker: Require explicit data location for all variables, including function parameters. This was partly already the case in the experimental 0.5.0 mode.
- Type Checker: Only accept a single
bytes
type for.call()
(and family),keccak256()
,sha256()
andripemd160()
. - Type Checker: Fallback function must be external. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Interface functions must be declared external. This was already the case in the experimental 0.5.0 mode.
- Type Checker: Address members are not included in contract types anymore. An explicit conversion is now required before invoking an
address
member from a contract. - Type Checker: Disallow "loose assembly" syntax entirely. This means that jump labels, jumps and non-functional instructions cannot be used anymore.
- Type System: Disallow explicit and implicit conversions from decimal literals to
bytesXX
types. - Type System: Disallow explicit and implicit conversions from hex literals to
bytesXX
types of different size. - Type System: Distinguish between payable and non-payable address types.
- View Pure Checker: Disallow
msg.value
in (or introducing it via a modifier to) a non-payable function. - Remove obsolete
std
directory from the Solidity repository. This means accessinghttps://github.com/ethereum/solidity/blob/develop/std/*.sol
(orhttps://github.com/ethereum/solidity/std/*.sol
in Remix) will not be possible. - References Resolver: Turn missing storage locations into an error. This was already the case in the experimental 0.5.0 mode.
- Syntax Checker: Disallow functions without implementation to use modifiers. This was already the case in the experimental 0.5.0 mode.
- Syntax Checker: Named return values in function types are an error.
- Syntax Checker: Strictly require visibility specifier for functions. This was already the case in the experimental 0.5.0 mode.
- Syntax Checker: Disallow unary
+
. This was already the case in the experimental 0.5.0 mode. - Syntax Checker: Disallow single statement variable declaration inside if/while/for bodies that are not blocks.
- View Pure Checker: Strictly enforce state mutability. This was already the case in the experimental 0.5.0 mode.
Language Features:
- General: Add
staticcall
toaddress
. - General: Allow appending
calldata
keyword to types, to explicitly specify data location for arguments of external functions. - General: Support
pop()
for storage arrays. - General: Scoping rules now follow the C99-style.
- General: Allow
enum
s in interfaces. - General: Allow
mapping
storage pointers as arguments and return values in all internal functions. - General: Allow
struct
s in interfaces. - General: Provide access to the ABI decoder through
abi.decode(bytes memory data, (...))
. - General: Disallow zero length for fixed-size arrays.
- Parser: Accept the
address payable
type during parsing.
Compiler Features:
- Build System: Support for Mojave version of macOS added.
- Code Generator:
CREATE2
instruction has been updated to match EIP1014 (aka "Skinny CREATE2"). It also is accepted as part of Constantinople. - Code Generator:
EXTCODEHASH
instruction has been added based on EIP1052. - Type Checker: Nicer error message when trying to reference overloaded identifiers in inline assembly.
- Type Checker: Show named argument in case of error.
- Type System: IntegerType is split into IntegerType and AddressType internally.
- Tests: Determine transaction status during IPC calls.
- Code Generator: Allocate and free local variables according to their scope.
- Removed
pragma experimental "v0.5.0";
. - Syntax Checker: Improved error message for lookup in function types.
- Name Resolver: Updated name suggestion look up function to take into account length of the identifier: 1: no search, 2-3: at most one change, 4-: at most two changes
- SMTChecker: Support calls to internal functions that return none or a single value.
Bugfixes:
- Build System: Support versions of CVC4 linked against CLN instead of GMP. In case of compilation issues due to the experimental SMT solver support, the solvers can be disabled when configuring the project with CMake using
-DUSE_CVC4=OFF
or-DUSE_Z3=OFF
. - Tests: Fix chain parameters to make ipc tests work with newer versions of cpp-ethereum.
- Code Generator: Fix allocation of byte arrays (zeroed out too much memory).
- Code Generator: Properly handle negative number literals in ABIEncoderV2.
- Code Generator: Do not crash on using a length of zero for multidimensional fixed-size arrays.
- Commandline Interface: Correctly handle paths with backslashes on windows.
- Control Flow Analyzer: Ignore unimplemented functions when detecting uninitialized storage pointer returns.
- Fix NatSpec json output for
@notice
and@dev
tags on contract definitions. - Optimizer: Correctly estimate gas costs of constants for special cases.
- Optimizer: Fix simplification rule initialization bug that appeared on some emscripten platforms.
- References Resolver: Do not crash on using
_slot
and_offset
suffixes on their own. - References Resolver: Enforce
storage
as data location for mappings. - References Resolver: Properly handle invalid references used together with
_slot
and_offset
. - References Resolver: Report error instead of assertion fail when FunctionType has an undeclared type as parameter.
- References Resolver: Fix high CPU usage when using large variable names issue. Only suggest similar name if identifiers shorter than 80 characters.
- Type Checker: Default data location for type conversions (e.g. from literals) is memory and not storage.
- Type Checker: Disallow assignments to mappings within tuple assignments as well.
- Type Checker: Disallow packed encoding of arrays of structs.
- Type Checker: Allow assignments to local variables of mapping types.
- Type Checker: Consider fixed size arrays when checking for recursive structs.
- Type Checker: Fix crashes in erroneous tuple assignments in which the type of the right hand side cannot be determined.
- Type Checker: Fix freeze for negative fixed-point literals very close to
0
, such as-1e-100
. - Type Checker: Dynamic types as key for public mappings return error instead of assertion fail.
- Type Checker: Fix internal error when array index value is too large.
- Type Checker: Fix internal error when fixed-size array is too large to be encoded.
- Type Checker: Fix internal error for array type conversions.
- Type Checker: Fix internal error when array index is not an unsigned.
- Type System: Allow arbitrary exponents for literals with a mantissa of zero.
- Parser: Fix incorrect source location for nameless parameters.
- Command Line Interface: Fix internal error when compiling stdin with no content and --ast option.
Important Bugfixes:
- Code Generator: Fix initialization routine of uninitialized internal function pointers in constructor context.
- Type System: Use correct type name for contracts in event parameters when used in libraries. This affected code generation.
Bugfixes:
- ABIEncoderV2: Refuse to generate code that is known to be potentially buggy.
- General: Split rule list such that JavaScript environments with small stacks can use the compiler.
Note: The above changes are not included in 0.5.0, because they were backported.
Important Bugfixes:
- Code Generator: Properly perform cleanup for exponentiation and non-256 bit types.
- Type Checker: Report error when using indexed structs in events with experimental ABIEncoderV2. This used to log wrong values.
- Type Checker: Report error when using structs in events without experimental ABIEncoderV2. This used to crash or log the wrong values.
- Parser: Consider all unicode line terminators (LF, VF, FF, CR, NEL, LS, PS) for single-line comments and string literals. They are invalid in strings and will end comments.
- Parser: Disallow unterminated multi-line comments at the end of input.
- Parser: Treat
/** /
as unterminated multi-line comment.
Language Features:
- Code Generator: Use native shift instructions on target Constantinople.
- General: Allow multiple variables to be declared as part of a tuple assignment, e.g.
(uint a, uint b) = ...
. - General: Remove deprecated
constant
as function state modifier from documentation and tests (but still leave it as a valid feature). - Type Checker: Deprecate the
years
unit denomination and raise a warning for it (or an error as experimental 0.5.0 feature). - Type Checker: Make literals (without explicit type casting) an error for tight packing as experimental 0.5.0 feature.
- Type Checker: Warn about wildcard tuple assignments (this will turn into an error with version 0.5.0).
- Type Checker: Warn when
keccak256
,sha256
andripemd160
are not used with a single bytes argument (suggest to useabi.encodePacked(...)
). This will turn into an error with version 0.5.0.
Compiler Features:
- Build System: Update internal dependency of jsoncpp to 1.8.4, which introduces more strictness and reduces memory usage.
- Control Flow Graph: Add Control Flow Graph as analysis structure.
- Control Flow Graph: Warn about returning uninitialized storage pointers.
- Gas Estimator: Only explore paths with higher gas costs. This reduces accuracy but greatly improves the speed of gas estimation.
- Optimizer: Remove unnecessary masking of the result of known short instructions (
ADDRESS
,CALLER
,ORIGIN
andCOINBASE
). - Parser: Display nicer error messages by showing the actual tokens and not internal names.
- Parser: Use the entire location of the token instead of only its starting position as source location for parser errors.
- SMT Checker: Support state variables of integer and bool type.
Bugfixes:
- Code Generator: Fix
revert
with reason coming from a state or local string variable. - Type Checker: Show proper error when trying to
emit
a non-event. - Type Checker: Warn about empty tuple components (this will turn into an error with version 0.5.0).
- Type Checker: The ABI encoding functions are pure and thus can be used for constants.
Features:
- Build system: Support Ubuntu Bionic.
- SMTChecker: Integration with CVC4 SMT solver
- Syntax Checker: Warn about functions named "constructor".
Bugfixes:
- Type Checker: Improve error message for failed function overload resolution.
- Type Checker: Do not complain about new-style constructor and fallback function to have the same name.
- Type Checker: Detect multiple constructor declarations in the new syntax and old syntax.
- Type Checker: Explicit conversion of
bytesXX
tocontract
is properly disallowed.
Features:
- Code Generator: Initialize arrays without using
msize()
. - Code Generator: More specialized and thus optimized implementation for
x.push(...)
- Commandline interface: Error when missing or inaccessible file detected. Suppress it with the
--ignore-missing
flag. - Constant Evaluator: Fix evaluation of single element tuples.
- General: Add encoding routines
abi.encodePacked
,abi.encode
,abi.encodeWithSelector
andabi.encodeWithSignature
. - General: Add global function
gasleft()
and deprecatemsg.gas
. - General: Add global function
blockhash(uint)
and deprecateblock.hash(uint)
. - General: Allow providing reason string for
revert()
andrequire()
. - General: Introduce new constructor syntax using the
constructor
keyword as experimental 0.5.0 feature. - General: Limit the number of errors output in a single run to 256.
- General: Support accessing dynamic return data in post-byzantium EVMs.
- General: Allow underscores in numeric and hex literals to separate thousands and quads.
- Inheritance: Error when using empty parentheses for base class constructors that require arguments as experimental 0.5.0 feature.
- Inheritance: Error when using no parentheses in modifier-style constructor calls as experimental 0.5.0 feature.
- Interfaces: Allow overriding external functions in interfaces with public in an implementing contract.
- Optimizer: Optimize
SHL
andSHR
only involving constants (Constantinople only). - Optimizer: Remove useless
SWAP1
instruction preceding a commutative instruction (such asADD
,MUL
, etc). - Optimizer: Replace comparison operators (
LT
,GT
, etc) with opposites if preceded bySWAP1
, e.g.SWAP1 LT
is replaced withGT
. - Optimizer: Optimize across
mload
ifmsize()
is not used. - Static Analyzer: Error on duplicated super constructor calls as experimental 0.5.0 feature.
- Syntax Checker: Issue warning for empty structs (or error as experimental 0.5.0 feature).
- Syntax Checker: Warn about modifiers on functions without implementation (this will turn into an error with version 0.5.0).
- Syntax Tests: Add source locations to syntax test expectations.
- Type Checker: Improve documentation and warnings for accessing contract members inherited from
address
.
Bugfixes:
- Code Generator: Allow
block.blockhash
without being called. - Code Generator: Do not include internal functions in the runtime bytecode which are only referenced in the constructor.
- Code Generator: Properly skip unneeded storage array cleanup when not reducing length.
- Code Generator: Bugfix in modifier lookup in libraries.
- Code Generator: Implement packed encoding of external function types.
- Code Generator: Treat empty base constructor argument list as not provided.
- Code Generator: Properly force-clean bytesXX types for shortening conversions.
- Commandline interface: Fix error messages for imported files that do not exist.
- Commandline interface: Support
--evm-version constantinople
properly. - DocString Parser: Fix error message for empty descriptions.
- Gas Estimator: Correctly ignore costs of fallback function for other functions.
- JSON AST: Remove storage qualifier for type name strings.
- Parser: Fix internal compiler error when parsing
var
declaration without identifier. - Parser: Fix parsing of getters for function type variables.
- Standard JSON: Support
constantinople
asevmVersion
properly. - Static Analyzer: Fix non-deterministic order of unused variable warnings.
- Static Analyzer: Invalid arithmetic with constant expressions causes errors.
- Type Checker: Fix detection of recursive structs.
- Type Checker: Fix asymmetry bug when comparing with literal numbers.
- Type System: Improve error message when attempting to shift by a fractional amount.
- Type System: Make external library functions accessible.
- Type System: Prevent encoding of weird types.
- Type System: Restrict rational numbers to 4096 bits.
Features:
- Code Generator: Assert that
k != 0
formulmod(a, b, k)
andaddmod(a, b, k)
as experimental 0.5.0 feature. - Code Generator: Do not retain any gas in calls (except if EVM version is set to homestead).
- Code Generator: Use
STATICCALL
opcode for callingview
andpure
functions as experimental 0.5.0 feature. - General: C99/C++-style scoping rules (instead of JavaScript function scoping) take effect as experimental v0.5.0 feature.
- General: Improved messaging when error spans multiple lines of a sourcefile
- General: Support and recommend using
emit EventName();
to call events explicitly. - Inline Assembly: Enforce strict mode as experimental 0.5.0 feature.
- Interface: Provide ability to select target EVM version (homestead or byzantium, with byzantium being the default).
- Standard JSON: Reject badly formatted invalid JSON inputs.
- Type Checker: Disallow uninitialized storage pointers as experimental 0.5.0 feature.
- Syntax Analyser: Do not warn about experimental features if they do not concern code generation.
- Syntax Analyser: Do not warn about
pragma experimental "v0.5.0"
and do not set the experimental flag in the bytecode for this. - Syntax Checker: Mark
throw
as an error as experimental 0.5.0 feature. - Syntax Checker: Issue error if no visibility is specified on contract functions as experimental 0.5.0 feature.
- Syntax Checker: Issue warning when using overloads of
address
on contract instances. - Type Checker: disallow combining hex numbers and unit denominations as experimental 0.5.0 feature.
Bugfixes:
- Assembly: Raise error on oversized number literals in assembly.
- JSON-AST: Add "documentation" property to function, event and modifier definition.
- Resolver: Properly determine shadowing for imports with aliases.
- Standalone Assembly: Do not ignore input after closing brace of top level block.
- Standard JSON: Catch errors properly when invalid "sources" are passed.
- Standard JSON: Ensure that library addresses supplied are of correct length and hex prefixed.
- Type Checker: Properly detect which array and struct types are unsupported by the old ABI encoder.
- Type Checker: Properly warn when using
_offset
and_slot
for constants in inline assembly. - Commandline interface: throw error if option is unknown
Features:
- Code Generator: Prevent non-view functions in libraries from being called directly (as opposed to via delegatecall).
- Commandline interface: Support strict mode of assembly (disallowing jumps,
instructional opcodes, etc) with the
--strict-assembly
switch. - Inline Assembly: Issue warning for using jump labels (already existed for jump instructions).
- Inline Assembly: Support some restricted tokens (return, byte, address) as identifiers in Iulia mode.
- Optimiser: Replace
x % 2**i
byx & (2**i-1)
. - Resolver: Continue resolving references after the first error.
- Resolver: Suggest alternative identifiers if a given identifier is not found.
- SMT Checker: Take if-else branch conditions into account in the SMT encoding of the program variables.
- Syntax Checker: Deprecate the
var
keyword (and mark it an error as experimental 0.5.0 feature). - Type Checker: Allow
this.f.selector
to be a pure expression. - Type Checker: Issue warning for using
public
visibility for interface functions. - Type Checker: Limit the number of warnings raised for creating abstract contracts.
Bugfixes:
- Error Output: Truncate huge number literals in the middle to avoid output blow-up.
- Parser: Disallow event declarations with no parameter list.
- Standard JSON: Populate the
sourceLocation
field in the error list. - Standard JSON: Properly support contract and library file names containing a colon (such as URLs).
- Type Checker: Suggest the experimental ABI encoder if using
struct
s as function parameters (instead of an internal compiler error). - Type Checker: Improve error message for wrong struct initialization.
Features:
- Code Generator: New ABI decoder which supports structs and arbitrarily nested
arrays and checks input size (activate using
pragma experimental ABIEncoderV2;
). - General: Allow constant variables to be used as array length.
- Inline Assembly:
if
statement. - Standard JSON: Support the
outputSelection
field for selective compilation of target artifacts. - Syntax Checker: Turn the usage of
callcode
into an error as experimental 0.5.0 feature. - Type Checker: Improve address checksum warning.
- Type Checker: More detailed errors for invalid array lengths (such as division by zero).
Bugfixes:
Features:
- Code Generator: Always use all available gas for calls as experimental 0.5.0 feature (previously, some amount was retained in order to work in pre-Tangerine-Whistle EVM versions)
- Parser: Better error message for unexpected trailing comma in parameter lists.
- Standard JSON: Support the
outputSelection
field for selective compilation of supplied sources. - Syntax Checker: Unary
+
is now a syntax error as experimental 0.5.0 feature. - Type Checker: Disallow non-pure constant state variables as experimental 0.5.0 feature.
- Type Checker: Do not add members of
address
to contracts as experimental 0.5.0 feature. - Type Checker: Force interface functions to be external as experimental 0.5.0 feature.
- Type Checker: Require
storage
ormemory
keyword for local variables as experimental 0.5.0 feature. - Compiler Interface: Better formatted error message for long source snippets
Bugfixes:
- Code Generator: Allocate one byte per memory byte array element instead of 32.
- Code Generator: Do not accept data with less than four bytes (truncated function signature) for regular function calls - fallback function is invoked instead.
- Optimizer: Remove unused stack computation results.
- Parser: Fix source location of VariableDeclarationStatement.
- Type Checker: Allow
gas
in view functions. - Type Checker: Do not mark event parameters as shadowing state variables.
- Type Checker: Prevent duplicate event declarations.
- Type Checker: Properly check array length and don't rely on an assertion in code generation.
- Type Checker: Properly support overwriting members inherited from
address
in a contract (such asbalance
,transfer
, etc.) - Type Checker: Validate each number literal in tuple expressions even if they are not assigned from.
Features:
- Assembly Parser: Support multiple assignment (
x, y := f()
). - Code Generator: Keep a single copy of encoding functions when using the experimental "ABIEncoderV2".
- Code Generator: Partial support for passing
structs
as arguments and return parameters (requirespragma experimental ABIEncoderV2;
for now). - General: Support
pragma experimental "v0.5.0";
to activate upcoming breaking changes. - General: Added
.selector
member on external function types to retrieve their signature. - Optimizer: Add new optimization step to remove unused
JUMPDEST
s. - Static Analyzer: Warn when using deprecated builtins
sha3
andsuicide
(replaced bykeccak256
andselfdestruct
, introduced in 0.4.2 and 0.2.0, respectively). - Syntax Checker: Warn if no visibility is specified on contract functions.
- Type Checker: Display helpful warning for unused function arguments/return parameters.
- Type Checker: Do not show the same error multiple times for events.
- Type Checker: Greatly reduce the number of duplicate errors shown for duplicate constructors and functions.
- Type Checker: Warn on using literals as tight packing parameters in
keccak256
,sha3
,sha256
andripemd160
. - Type Checker: Enforce
view
andpure
. - Type Checker: Enforce
view
/constant
with error as experimental 0.5.0 feature. - Type Checker: Enforce fallback functions to be
external
as experimental 0.5.0 feature.
Bugfixes:
- ABI JSON: Include all overloaded events.
- Parser: Crash fix related to parseTypeName.
- Type Checker: Allow constant byte arrays.
Features:
- ABI JSON: Include new field
stateMutability
with valuespure
,view
,nonpayable
andpayable
. - Analyzer: Experimental partial support for Z3 SMT checker ("SMTChecker").
- Build System: Shared libraries (
libsolutil
,libevmasm
,libsolidity
andliblll
) are no longer produced during the build process. - Code generator: Experimental new implementation of ABI encoder that can encode arbitrarily nested arrays ("ABIEncoderV2")
- Metadata: Store experimental flag in metadata CBOR.
- Parser: Display previous visibility specifier in error if multiple are found.
- Parser: Introduce
pure
andview
keyword for functions,constant
remains an alias forview
and pureness is not enforced yet, so use with care. - Static Analyzer: Warn about large storage structures.
- Syntax Checker: Support
pragma experimental <feature>;
to turn on experimental features. - Type Checker: More detailed error message for invalid overrides.
- Type Checker: Warn about shifting a literal.
Bugfixes:
- Assembly Parser: Be more strict about number literals.
- Assembly Parser: Limit maximum recursion depth.
- Parser: Enforce commas between array and tuple elements.
- Parser: Limit maximum recursion depth.
- Type Checker: Crash fix related to
using
. - Type Checker: Disallow constructors in libraries.
- Type Checker: Reject the creation of interface contracts using the
new
statement.
Features:
- Type Checker: Show unimplemented function if trying to instantiate an abstract class.
Bugfixes:
- Code Generator:
.delegatecall()
should always return execution outcome. - Code Generator: Provide "new account gas" for low-level
callcode
anddelegatecall
. - Type Checker: Constructors must be implemented if declared.
- Type Checker: Disallow the
.gas()
modifier onecrecover
,sha256
andripemd160
. - Type Checker: Do not mark overloaded functions as shadowing other functions.
- Type Checker: Internal library functions must be implemented if declared.
Features:
- C API (
jsonCompiler
): Export thelicense
method. - Code Generator: Optimise the fallback function, by removing a useless jump.
- Inline Assembly: Show useful error message if trying to access calldata variables.
- Inline Assembly: Support variable declaration without initial value (defaults to 0).
- Metadata: Only include files which were used to compile the given contract.
- Type Checker: Disallow value transfers to contracts without a payable fallback function.
- Type Checker: Include types in explicit conversion error message.
- Type Checker: Raise proper error for arrays too large for ABI encoding.
- Type checker: Warn if using
this
in a constructor. - Type checker: Warn when existing symbols, including builtins, are overwritten.
Bugfixes:
- Code Generator: Properly clear return memory area for ecrecover.
- Type Checker: Fix crash for some assignment to non-lvalue.
- Type Checker: Fix invalid "specify storage keyword" warning for reference members of structs.
- Type Checker: Mark modifiers as internal.
- Type Checker: Re-allow multiple mentions of the same modifier per function.
Features:
- Syntax Checker: Deprecated "throw" in favour of require(), assert() and revert().
- Type Checker: Warn if a local storage reference variable does not explicitly use the keyword
storage
.
Bugfixes:
- Code Generator: Correctly unregister modifier variables.
- Compiler Interface: Only output AST if analysis was successful.
- Error Output: Do not omit the error type.
Features:
- Assembly: Add
CREATE2
(EIP86),STATICCALL
(EIP214),RETURNDATASIZE
andRETURNDATACOPY
(EIP211) instructions. - Assembly: Display auxiliary data in the assembly output.
- Assembly: Renamed
SHA3
toKECCAK256
. - AST: export all attributes to JSON format.
- C API (
jsonCompiler
): Use the Standard JSON I/O internally. - Code Generator: Added the Whiskers template system.
- Inline Assembly:
for
andswitch
statements. - Inline Assembly: Function definitions and function calls.
- Inline Assembly: Introduce
keccak256
as an opcode.sha3
is still a valid alias. - Inline Assembly: Present proper error message when not supplying enough arguments to a functional instruction.
- Inline Assembly: Warn when instructions shadow Solidity variables.
- Inline Assembly: Warn when using
jump
s. - Remove obsolete Why3 output.
- Type Checker: Enforce strict UTF-8 validation.
- Type Checker: Warn about copies in storage that might overwrite unexpectedly.
- Type Checker: Warn about type inference from literal numbers.
- Static Analyzer: Warn about deprecation of
callcode
.
Bugfixes:
- Assembly: mark
MLOAD
to have side effects in the optimiser. - Code Generator: Fix ABI encoding of empty literal string.
- Code Generator: Fix negative stack size checks.
- Code generator: Use
REVERT
instead ofINVALID
for generated input validation routines. - Inline Assembly: Enforce function arguments when parsing functional instructions.
- Optimizer: Disallow optimizations involving
MLOAD
because it changesMSIZE
. - Static Analyzer: Unused variable warnings no longer issued for variables used inside inline assembly.
- Type Checker: Fix address literals not being treated as compile-time constants.
- Type Checker: Fixed crash concerning non-callable types.
- Type Checker: Fixed segfault with constant function parameters
- Type Checker: Disallow comparisons between mapping and non-internal function types.
- Type Checker: Disallow invoking the same modifier multiple times.
- Type Checker: Do not treat strings that look like addresses as addresses.
- Type Checker: Support valid, but incorrectly rejected UTF-8 sequences.
Features:
- Implement the Standard JSON Input / Output API
- Support
interface
contracts. - C API (
jsonCompiler
): Add thecompileStandard()
method to process a Standard JSON I/O. - Commandline interface: Add the
--standard-json
parameter to process a Standard JSON I/O. - Commandline interface: Support
--allow-paths
to define trusted import paths. Note: the path(s) of the supplied source file(s) is always trusted. - Inline Assembly: Storage variable access using
_slot
and_offset
suffixes. - Inline Assembly: Disallow blocks with unbalanced stack.
- Static analyzer: Warn about statements without effects.
- Static analyzer: Warn about unused local variables, parameters, and return parameters.
- Syntax checker: issue deprecation warning for unary '+'
Bugfixes:
- Assembly output: Implement missing AssemblyItem types.
- Compiler interface: Fix a bug where source indexes could be inconsistent between Solidity compiled with different compilers (clang vs. gcc) or compiler settings. The bug was visible in AST and source mappings.
- Gas Estimator: Reflect the most recent fee schedule.
- Type system: Contract inheriting from base with unimplemented constructor should be abstract.
- Optimizer: Number representation bug in the constant optimizer fixed.
Features:
- Add
assert(condition)
, which throws if condition is false (meant for internal errors). - Add
require(condition)
, which throws if condition is false (meant for invalid input). - Commandline interface: Do not overwrite files unless forced.
- Introduce
.transfer(value)
for sending Trx. - Code generator: Support
revert()
to abort with rolling back, but not consuming all gas. - Inline assembly: Support
revert
(EIP140) as an opcode. - Parser: Support scientific notation in numbers (e.g.
2e8
and200e-2
). - Type system: Support explicit conversion of external function to address.
- Type system: Warn if base of exponentiation is literal (result type might be unexpected).
- Type system: Warn if constant state variables are not compile-time constants.
Bugfixes:
- Commandline interface: Always escape filenames (replace
/
,:
and.
with_
). - Commandline interface: Do not try creating paths
.
and..
. - Commandline interface: Allow long library names.
- Parser: Disallow octal literals.
- Type system: Fix a crash caused by continuing on fatal errors in the code.
- Type system: Disallow compound assignment for tuples.
- Type system: Detect cyclic dependencies between constants.
- Type system: Disallow arrays with negative length.
- Type system: Fix a crash related to invalid binary operators.
- Type system: Disallow
var
declaration with empty tuple type. - Type system: Correctly convert function argument types to pointers for member functions.
- Type system: Move privateness of constructor into AST itself.
- Inline assembly: Charge one stack slot for non-value types during analysis.
- Assembly output: Print source location before the operation it refers to instead of after.
- Optimizer: Stop trying to optimize tricky constants after a while.
Features:
- Compiler interface: Contracts and libraries can be referenced with a
file:
prefix to make them unique. - Compiler interface: Report source location for "stack too deep" errors.
- AST: Use deterministic node identifiers.
- Inline assembly: introduce
invalid
(EIP141) as an opcode. - Type system: Introduce type identifier strings.
- Type checker: Warn about invalid checksum for addresses and deduce type from valid ones.
- Metadata: Do not include platform in the version number.
- Metadata: Add option to store sources as literal content.
- Code generator: Extract array utils into low-level functions.
- Code generator: Internal errors (array out of bounds, etc.) now cause a reversion by using an invalid instruction (0xfe - EIP141) instead of an invalid jump. Invalid jump is still kept for explicit throws.
Bugfixes:
- Code generator: Allow recursive structs.
- Inline assembly: Disallow variables named like opcodes.
- Type checker: Allow multiple events of the same name (but with different arities or argument types)
- Natspec parser: Fix error with
@param
parsing and whitespace.
Features:
- Optimiser: Performance improvements.
- Output: Print assembly in new standardized Solidity assembly format.
Bugfixes:
- Remappings: Prefer longer context over longer prefix.
- Type checker, code generator: enable access to events of base contracts' names.
- Imports:
import ".dir/a"
is not a relative path. Relative paths begin with directory.
or..
. - Type checker, disallow inheritances of different kinds (e.g. a function and a modifier) of members of the same name
Features:
- Bitshift operators.
- Type checker: Warn when
msg.value
is used in non-payable function. - Code generator: Inject the Swarm hash of a metadata file into the bytecode.
- Code generator: Replace expensive memcpy precompile by simple assembly loop.
- Optimizer: Some dead code elimination.
Bugfixes:
- Code generator: throw if calling the identity precompile failed during memory (array) copying.
- Type checker: string literals that are not valid UTF-8 cannot be converted to string type
- Code generator: any non-zero value given as a boolean argument is now converted into 1.
- AST Json Converter: replace
VariableDefinitionStatement
nodes withVariableDeclarationStatement
- AST Json Converter: fix the camel case in
ElementaryTypeNameExpression
- AST Json Converter: replace
public
field withvisibility
in the function definition nodes
Bugfixes:
- Optimizer: Knowledge about state was not correctly cleared for JUMPDESTs (introduced in 0.4.5)
Features:
- Function types
- Do-while loops: support for a
do <block> while (<expr>);
control structure - Inline assembly: support
invalidJumpLabel
as a jump label. - Type checker: now more eagerly searches for a common type of an inline array with mixed types
- Code generator: generates a runtime error when an out-of-range value is converted into an enum type.
Bugfixes:
- Inline assembly: calculate stack height warning correctly even when local variables are used.
- Code generator: check for value transfer in non-payable constructors.
- Parser: disallow empty enum definitions.
- Type checker: disallow conversion between different enum types.
- Interface JSON: do not include trailing new line.
Bugfixes:
- Type checker: forbid signed exponential that led to an incorrect use of EXP opcode.
- Code generator: properly clean higher order bytes before storing in storage.
Features:
- Inline assembly: support both
suicide
andselfdestruct
opcodes (note:suicide
is deprecated). - Inline assembly: issue warning if stack is not balanced after block.
- Include
keccak256()
as an alias tosha3()
. - Support shifting constant numbers.
Bugfixes:
- Commandline interface: Disallow unknown options in
solc
. - Name resolver: Allow inheritance of
enum
definitions. - Type checker: Proper type checking for bound functions.
- Type checker: fixed crash related to invalid fixed point constants
- Type checker: fixed crash related to invalid literal numbers.
- Type checker:
super.x
does not look upx
in the current contract. - Code generator: expect zero stack increase after
super
as an expression. - Code generator: fix an internal compiler error for
L.Foo
forenum Foo
defined in libraryL
. - Code generator: allow inheritance of
enum
definitions. - Inline assembly: support the
address
opcode. - Inline assembly: fix parsing of assignment after a label.
- Inline assembly: external variables of unsupported type (such as
this
,super
, etc.) are properly detected as unusable. - Inline assembly: support variables within modifiers.
- Optimizer: fix related to stale knowledge about SHA3 operations
Bugfixes:
- Code Generator: Fix library functions being called from payable functions.
- Type Checker: Fixed a crash about invalid array types.
- Code Generator: Fixed a call gas bug that became visible after version 0.4.0 for calls where the output is larger than the input.
- Build System: Fixes to allow library compilation.
This release deliberately breaks backwards compatibility mostly to
enforce some safety features. The most important change is that you have
to explicitly specify if functions can receive trx via the payable
modifier. Furthermore, more situations cause exceptions to be thrown.
Minimal changes to be made for upgrade:
- Add
payable
to all functions that want to receive Trx (including the constructor and the fallback function). - Change
_
to_;
in modifiers. - Add version pragma to each file:
pragma solidity ^0.4.0;
Breaking Changes:
- Source files have to specify the compiler version they are
compatible with using e.g.
pragma solidity ^0.4.0;
orpragma solidity >=0.4.0 <0.4.8;
- Functions that want to receive Trx have to specify the
new
payable
modifier (otherwise they throw). - Contracts that want to receive Trx with a plain "send"
have to implement a fallback function with the
payable
modifier. Contracts now throw if no payable fallback function is defined and no function matches the signature. - Failing contract creation through "new" throws.
- Division / modulus by zero throws.
- Function call throws if target contract does not have code
- Modifiers are required to contain
_
(useif (false) _
as a workaround if needed). - Modifiers: return does not skip part in modifier after
_
. - Placeholder statement
_
in modifier now requires explicit;
. ecrecover
now returns zero if the input is malformed (it previously returned garbage).- The
constant
keyword cannot be used for constructors or the fallback function. - Removed
--interface
(Solidity interface) output option - JSON AST: General cleanup, renamed many nodes to match their C++ names.
- JSON output:
srcmap-runtime
renamed tosrcmapRuntime
. - Moved (and reworked) standard library contracts from inside the compiler to github.com/ethereum/solidity/std
(
import "std";
orimport owned;
do not work anymore). - Confusing and undocumented keyword
after
was removed. - New reserved words:
abstract
,hex
,interface
,payable
,pure
,static
,view
.
Features:
- Hexadecimal string literals:
hex"ab1248fe"
- Internal: Inline assembly usable by the code generator.
- Commandline interface: Using
-
as filename allows reading from stdin. - Interface JSON: Fallback function is now part of the ABI.
- Interface: Version string now SemVer compatible.
- Code generator: Do not provide "new account gas" if we know the called account exists.
Bugfixes:
- JSON AST: Nodes were added at wrong parent
- Why3 translator: Crash fix for exponentiation
- Commandline Interface: linking libraries with underscores in their name.
- Type Checker: Fallback function cannot return data anymore.
- Code Generator: Fix crash when
sha3()
was used on unsupported types. - Code Generator: Manually set gas stipend for
.send(0)
.
Lots of changes to the documentation mainly by voluntary external contributors.
Features:
- Formal verification: Take external effects on a contract into account.
- Type Checker: Warning about unused return value of low-level calls and send.
- Output: Source location and node id as part of AST output
- Output: Source location mappings for bytecode
- Output: Formal verification as part of json compiler output.
Bugfixes:
- Commandline Interface: Do not crash if input is taken from stdin.
- Scanner: Correctly support unicode escape codes in strings.
- JSON output: Fix error about relative / absolute source file names.
- JSON output: Fix error about invalid utf8 strings.
- Code Generator: Dynamic allocation of empty array caused infinite loop.
- Code Generator: Correctly calculate gas requirements for memcpy precompile.
- Optimizer: Clear known state if two code paths are joined.
Features:
- Context-dependent path remappings (different modules can use the same library in different versions)
Bugfixes:
- Type Checking: Dynamic return types were removed when fetching data from external calls, now they are replaced by an "unusable" type.
- Type Checking: Overrides by constructors were considered making a function non-abstract.
No change outside documentation.
- Allow internal library functions to be called (by "inlining")
- Fractional/rational constants (only usable with fixed point types, which are still in progress)
- Inline assembly has access to internal functions (as jump labels)
- Running
solc
without arguments on a terminal will print help. - Bugfix: Remove some non-determinism in code generation.
- Bugfix: Corrected usage of not / bnot / iszero in inline assembly
- Bugfix: Correctly clean bytesNN types before comparison
- Bugfix: Inline assembly parser:
byte
opcode was unusable - Bugfix: Error reporting: tokens for variably-sized types were not converted to string properly
- Bugfix: Dynamic arrays of structs were not deleted correctly.
- Bugfix: Static arrays in constructor parameter list were not decoded correctly.
- Inline assembly
- Bugfix: Code generation: array access with narrow types did not clean higher order bits
- Bugfix: Error reporting: error reporting with unknown source location caused a crash
BREAKING CHANGES:
- Added new keywords
assembly
,foreign
,fixed
,ufixed
,fixedNxM
,ufixedNxM
(for various values of M and N),timestamp
- Number constant division does not round to integer, but to a fixed point type (e.g.
1 / 2 != 1
, but1 / 2 == 0.5
). - Library calls now default to use DELEGATECALL (e.g. called library functions see the same value as the calling function for
msg.value
andmsg.sender
). <address>.delegatecall
as a low-level calling interface
Bugfixes:
- Fixed a bug in the optimizer that resulted in comparisons being wrong.
- Index access for types
bytes1
, ...,bytes32
(only read access for now). - Bugfix: Type checker crash for wrong number of base constructor parameters.
- Inline arrays, i.e.
var y = [1,x,f()];
if there is a common type for1
,x
andf()
. Note that the result is always a fixed-length memory array and conversion to dynamic-length memory arrays is not yet possible. - Import similar to ECMAScript6 import (
import "abc.sol" as d
andimport {x, y} from "abc.sol"
). - Commandline compiler solc automatically resolves missing imports and allows for "include directories".
- Conditional:
x ? y : z
- Bugfix: Fixed several bugs where the optimizer generated invalid code.
- Bugfix: Enums and structs were not accessible to other contracts.
- Bugfix: Fixed segfault connected to function parameter types, appeared during gas estimation.
- Bugfix: Type checker crash for wrong number of base constructor parameters.
- Bugfix: Allow function overloads with different array types.
- Bugfix: Allow assignments of type
(x) = 7
. - Bugfix: Type
uint176
was not available. - Bugfix: Fixed crash during type checking concerning constructor calls.
- Bugfix: Fixed crash during code generation concerning invalid accessors for struct types.
- Bugfix: Fixed crash during code generating concerning computing a hash of a struct type.
- Breaking Change:
new ContractName.value(10)()
has to be written as(new ContractName).value(10)()
- Added
selfdestruct
as an alias forsuicide
. - Allocation of memory arrays using
new
. - Binding library functions to types via
using x for y
addmod
andmulmod
(modular addition and modular multiplication with arbitrary intermediate precision)- Bugfix: Constructor arguments of fixed array type were not read correctly.
- Bugfix: Memory allocation of structs containing arrays or strings.
- Bugfix: Data location for explicit memory parameters in libraries was set to storage.
- Improved error messages for unexpected tokens.
- Proof-of-concept transcompilation to why3 for formal verification of contracts.
- Bugfix: Arrays (also strings) as indexed parameters of events.
- Bugfix: Writing to elements of
bytes
orstring
overwrite others. - Bugfix: "Successor block not found" on Windows.
- Bugfix: Using string literals in tuples.
- Bugfix: Cope with invalid commit hash in version for libraries.
- Bugfix: Some test framework fixes on windows.
.push()
for dynamic storage arrays.- Tuple expressions (
(1,2,3)
orreturn (1,2,3);
) - Declaration and assignment of multiple variables (
var (x,y,) = (1,2,3,4,5);
orvar (x,y) = f();
) - Destructuring assignment (
(x,y,) = (1,2,3)
) - Bugfix: Internal error about usage of library function with invalid types.
- Bugfix: Correctly parse
Library.structType a
at statement level. - Bugfix: Correctly report source locations of parenthesized expressions (as part of "tuple" story).
- Breaking change in storage encoding: Encode short byte arrays and strings together with their length in storage.
- Report warnings
- Allow storage reference types for public library functions.
- Access to types declared in other contracts and libraries via
.
. - Version stamp at beginning of runtime bytecode of libraries.
- Bugfix: Problem with initialized string state variables and dynamic data in constructor.
- Bugfix: Resolve dependencies concerning
new
automatically. - Bugfix: Allow four indexed arguments for anonymous events.
- Bugfix: Detect too large integer constants in functions that accept arbitrary parameters.
- Bugfix: Returning fixed-size arrays.
- Bugfix: combined-json output of solc.
- Bugfix: Accessing fixed-size array return values.
- Bugfix: Disallow assignment from literal strings to storage pointers.
- Refactoring: Move type checking into its own module.
throw
statement.- Libraries that contain functions which are called via CALLCODE.
- Linker stage for compiler to insert other contract's addresses (used for libraries).
- Compiler option to output runtime part of contracts.
- Compile-time out of bounds check for access to fixed-size arrays by integer constants.
- Version string includes libevmasm/libethereum's version (contains the optimizer).
- Bugfix: Accessors for constant public state variables.
- Bugfix: Propagate exceptions in clone contracts.
- Bugfix: Empty single-line comments are now treated properly.
- Bugfix: Properly check the number of indexed arguments for events.
- Bugfix: Strings in struct constructors.
- Improved commandline interface.
- Explicit conversion between
bytes
andstring
. - Bugfix: Value transfer used in clone contracts.
- Bugfix: Problem with strings as mapping keys.
- Bugfix: Prevent usage of some operators.
- Strings can be used as mapping keys.
- Clone contracts.
- Mapping members are skipped for structs in memory.
- Use only a single stack slot for storage references.
- Improved error message for wrong argument count. (#2456)
- Bugfix: Fix comparison between
bytesXX
types. (#2087) - Bugfix: Do not allow floats for integer literals. (#2078)
- Bugfix: Some problem with many local variables. (#2478)
- Bugfix: Correctly initialise
string
andbytes
state variables. - Bugfix: Correctly compute gas requirements for callcode.