From e1a4bf6492ea235b19fe1b390116b1973749466f Mon Sep 17 00:00:00 2001 From: Erik Desjardins Date: Fri, 4 Mar 2022 23:14:38 -0500 Subject: [PATCH] cleanup: remove unused ability to have LLVM null-terminate const strings --- compiler/rustc_codegen_gcc/src/common.rs | 20 +++------- compiler/rustc_codegen_gcc/src/context.rs | 4 +- compiler/rustc_codegen_llvm/src/common.rs | 44 ++++++++-------------- compiler/rustc_codegen_llvm/src/context.rs | 4 +- 4 files changed, 26 insertions(+), 46 deletions(-) diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs index 5851826147dfa..3c0dad13deac6 100644 --- a/compiler/rustc_codegen_gcc/src/common.rs +++ b/compiler/rustc_codegen_gcc/src/common.rs @@ -26,18 +26,6 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> { bytes_in_context(self, bytes) } - fn const_cstr(&self, symbol: Symbol, _null_terminated: bool) -> LValue<'gcc> { - // TODO(antoyo): handle null_terminated. - if let Some(&value) = self.const_cstr_cache.borrow().get(&symbol) { - return value; - } - - let global = self.global_string(symbol.as_str()); - - self.const_cstr_cache.borrow_mut().insert(symbol, global); - global - } - fn global_string(&self, string: &str) -> LValue<'gcc> { // TODO(antoyo): handle non-null-terminated strings. let string = self.context.new_string_literal(&*string); @@ -171,8 +159,12 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> { } fn const_str(&self, s: Symbol) -> (RValue<'gcc>, RValue<'gcc>) { - let len = s.as_str().len(); - let cs = self.const_ptrcast(self.const_cstr(s, false).get_address(None), + let s_str = s.as_str(); + let str_global = *self.const_str_cache.borrow_mut().entry(s).or_insert_with(|| { + self.global_string(s_str) + }); + let len = s_str.len(); + let cs = self.const_ptrcast(str_global.get_address(None), self.type_ptr_to(self.layout_of(self.tcx.types.str_).gcc_type(self, true)), ); (cs, self.const_usize(len as u64)) diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs index dfcd1b6231216..6c1dce969f0f5 100644 --- a/compiler/rustc_codegen_gcc/src/context.rs +++ b/compiler/rustc_codegen_gcc/src/context.rs @@ -85,7 +85,7 @@ pub struct CodegenCx<'gcc, 'tcx> { pub const_globals: RefCell, RValue<'gcc>>>, /// Cache of constant strings, - pub const_cstr_cache: RefCell>>, + pub const_str_cache: RefCell>>, /// Cache of globals. pub globals: RefCell>>, @@ -195,7 +195,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> { function_instances: Default::default(), vtables: Default::default(), const_globals: Default::default(), - const_cstr_cache: Default::default(), + const_str_cache: Default::default(), globals: Default::default(), scalar_types: Default::default(), types: Default::default(), diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs index 9d34734f4e59a..8b8d770433227 100644 --- a/compiler/rustc_codegen_llvm/src/common.rs +++ b/compiler/rustc_codegen_llvm/src/common.rs @@ -106,32 +106,6 @@ impl<'ll> CodegenCx<'ll, '_> { bytes_in_context(self.llcx, bytes) } - fn const_cstr(&self, s: Symbol, null_terminated: bool) -> &'ll Value { - unsafe { - if let Some(&llval) = self.const_cstr_cache.borrow().get(&s) { - return llval; - } - - let s_str = s.as_str(); - let sc = llvm::LLVMConstStringInContext( - self.llcx, - s_str.as_ptr() as *const c_char, - s_str.len() as c_uint, - !null_terminated as Bool, - ); - let sym = self.generate_local_symbol_name("str"); - let g = self.define_global(&sym, self.val_ty(sc)).unwrap_or_else(|| { - bug!("symbol `{}` is already defined", sym); - }); - llvm::LLVMSetInitializer(g, sc); - llvm::LLVMSetGlobalConstant(g, True); - llvm::LLVMRustSetLinkage(g, llvm::Linkage::InternalLinkage); - - self.const_cstr_cache.borrow_mut().insert(s, g); - g - } - } - pub fn const_get_elt(&self, v: &'ll Value, idx: u64) -> &'ll Value { unsafe { assert_eq!(idx as c_uint as u64, idx); @@ -204,9 +178,23 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> { } fn const_str(&self, s: Symbol) -> (&'ll Value, &'ll Value) { - let len = s.as_str().len(); + let s_str = s.as_str(); + let str_global = *self.const_str_cache.borrow_mut().entry(s).or_insert_with(|| { + let sc = self.const_bytes(s_str.as_bytes()); + let sym = self.generate_local_symbol_name("str"); + let g = self.define_global(&sym, self.val_ty(sc)).unwrap_or_else(|| { + bug!("symbol `{}` is already defined", sym); + }); + unsafe { + llvm::LLVMSetInitializer(g, sc); + llvm::LLVMSetGlobalConstant(g, True); + llvm::LLVMRustSetLinkage(g, llvm::Linkage::InternalLinkage); + } + g + }); + let len = s_str.len(); let cs = consts::ptrcast( - self.const_cstr(s, false), + str_global, self.type_ptr_to(self.layout_of(self.tcx.types.str_).llvm_type(self)), ); (cs, self.const_usize(len as u64)) diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs index f102becf2bdba..52e03e0ad3d6b 100644 --- a/compiler/rustc_codegen_llvm/src/context.rs +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -55,7 +55,7 @@ pub struct CodegenCx<'ll, 'tcx> { pub vtables: RefCell, Option>), &'ll Value>>, /// Cache of constant strings, - pub const_cstr_cache: RefCell>, + pub const_str_cache: RefCell>, /// Reverse-direction for const ptrs cast from globals. /// @@ -415,7 +415,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> { codegen_unit, instances: Default::default(), vtables: Default::default(), - const_cstr_cache: Default::default(), + const_str_cache: Default::default(), const_unsized: Default::default(), const_globals: Default::default(), statics_to_rauw: RefCell::new(Vec::new()),