Auto merge of #47327 - MaloJaffre:beta-backport, r=Mark-Simulacrum

[beta] Backports

Cherry-picked (cleanly) into beta:
- #46916
- #47161
- #47208
- #47269

src/bootstrap/channel.rs

@@ -29,7 +29,7 @@ pub const CFG_RELEASE_NUM: &str = "1.24.0";
 // An optional number to put after the label, e.g. '.2' -> '-beta.2'
 // Be sure to make this starts with a dot to conform to semver pre-release
 // versions (section 9)
-pub const CFG_PRERELEASE_VERSION: &str = ".1";
+pub const CFG_PRERELEASE_VERSION: &str = ".2";
 
 pub struct GitInfo {
     inner: Option<Info>,

src/libcore/str/pattern.rs

@@ -284,7 +284,7 @@ unsafe impl<'a> Searcher<'a> for CharSearcher<'a> {
     #[inline]
     fn next(&mut self) -> SearchStep {
         let old_finger = self.finger;
-        let slice = unsafe { self.haystack.get_unchecked(old_finger..self.haystack.len()) };
+        let slice = unsafe { self.haystack.get_unchecked(old_finger..self.finger_back) };
         let mut iter = slice.chars();
         let old_len = iter.iter.len();
         if let Some(ch) = iter.next() {
@@ -304,7 +304,8 @@ unsafe impl<'a> Searcher<'a> for CharSearcher<'a> {
     fn next_match(&mut self) -> Option<(usize, usize)> {
         loop {
             // get the haystack after the last character found
-            let bytes = if let Some(slice) = self.haystack.as_bytes().get(self.finger..) {
+            let bytes = if let Some(slice) = self.haystack.as_bytes()
+                                                 .get(self.finger..self.finger_back) {
                 slice
             } else {
                 return None;
@@ -340,7 +341,7 @@ unsafe impl<'a> Searcher<'a> for CharSearcher<'a> {
                 }
             } else {
                 // found nothing, exit
-                self.finger = self.haystack.len();
+                self.finger = self.finger_back;
                 return None;
             }
         }
@@ -353,7 +354,7 @@ unsafe impl<'a> ReverseSearcher<'a> for CharSearcher<'a> {
     #[inline]
     fn next_back(&mut self) -> SearchStep {
         let old_finger = self.finger_back;
-        let slice = unsafe { self.haystack.slice_unchecked(0, old_finger) };
+        let slice = unsafe { self.haystack.slice_unchecked(self.finger, old_finger) };
         let mut iter = slice.chars();
         let old_len = iter.iter.len();
         if let Some(ch) = iter.next_back() {
@@ -374,14 +375,17 @@ unsafe impl<'a> ReverseSearcher<'a> for CharSearcher<'a> {
         let haystack = self.haystack.as_bytes();
         loop {
             // get the haystack up to but not including the last character searched
-            let bytes = if let Some(slice) = haystack.get(..self.finger_back) {
+            let bytes = if let Some(slice) = haystack.get(self.finger..self.finger_back) {
                 slice
             } else {
                 return None;
             };
             // the last byte of the utf8 encoded needle
             let last_byte = unsafe { *self.utf8_encoded.get_unchecked(self.utf8_size - 1) };
             if let Some(index) = memchr::memrchr(last_byte, bytes) {
+                // we searched a slice that was offset by self.finger,
+                // add self.finger to recoup the original index
+                let index = self.finger + index;
                 // memrchr will return the index of the byte we wish to
                 // find. In case of an ASCII character, this is indeed
                 // were we wish our new finger to be ("after" the found
@@ -412,7 +416,7 @@ unsafe impl<'a> ReverseSearcher<'a> for CharSearcher<'a> {
                 // found the last byte when searching in reverse.
                 self.finger_back = index;
             } else {
-                self.finger_back = 0;
+                self.finger_back = self.finger;
                 // found nothing, exit
                 return None;
             }

src/libcore/tests/pattern.rs

@@ -262,3 +262,41 @@ fn test_reverse_search_shared_bytes() {
         [InRange(37, 40), Rejects(34, 37), InRange(10, 13), Rejects(8, 10), Done]
     );
 }
+
+#[test]
+fn double_ended_regression_test() {
+    // https://github.com/rust-lang/rust/issues/47175
+    // Ensures that double ended searching comes to a convergence
+    search_asserts!("abcdeabcdeabcde", 'a', "alternating double ended search",
+        [next_match,    next_match_back,    next_match,      next_match_back],
+        [InRange(0, 1), InRange(10, 11), InRange(5, 6), Done]
+    );
+    search_asserts!("abcdeabcdeabcde", 'a', "triple double ended search for a",
+        [next_match,    next_match_back,    next_match_back,      next_match_back],
+        [InRange(0, 1), InRange(10, 11), InRange(5, 6), Done]
+    );
+    search_asserts!("abcdeabcdeabcde", 'd', "triple double ended search for d",
+        [next_match,    next_match_back,    next_match_back,      next_match_back],
+        [InRange(3, 4), InRange(13, 14), InRange(8, 9), Done]
+    );
+    search_asserts!(STRESS, 'Á', "Double ended search for two-byte Latin character",
+        [next_match,    next_match_back,     next_match,      next_match_back],
+        [InRange(0, 2), InRange(32, 34), InRange(8, 10), Done]
+    );
+    search_asserts!(STRESS, '각', "Reverse double ended search for three-byte Hangul character",
+        [next_match_back, next_back,       next_match,      next,            next_match_back, next_match],
+        [InRange(34, 37), Rejects(32, 34), InRange(19, 22), Rejects(22, 25), InRange(28, 31), Done]
+    );
+    search_asserts!(STRESS, 'ก', "Double ended search for three-byte Thai character",
+        [next_match,      next_back,       next,            next_match_back, next_match],
+        [InRange(22, 25), Rejects(47, 48), Rejects(25, 28), InRange(40, 43), Done]
+    );
+    search_asserts!(STRESS, '😁', "Double ended search for four-byte emoji",
+        [next_match_back, next,          next_match,      next_back,       next_match],
+        [InRange(43, 47), Rejects(0, 2), InRange(15, 19), Rejects(40, 43), Done]
+    );
+    search_asserts!(STRESS, 'ꁁ', "Double ended search for three-byte Yi character with repeated bytes",
+        [next_match,      next,            next_match_back, next_back,       next_match],
+        [InRange(10, 13), Rejects(13, 14), InRange(37, 40), Rejects(34, 37), Done]
+    );
+}

src/librustc/Cargo.toml

@@ -14,7 +14,7 @@ bitflags = "1.0"
 fmt_macros = { path = "../libfmt_macros" }
 graphviz = { path = "../libgraphviz" }
 jobserver = "0.1"
-log = "0.3"
+log = "0.4"
 rustc_apfloat = { path = "../librustc_apfloat" }
 rustc_back = { path = "../librustc_back" }
 rustc_const_math = { path = "../librustc_const_math" }

src/librustc/hir/map/mod.rs

@@ -1068,7 +1068,7 @@ pub fn map_crate<'hir>(sess: &::session::Session,
                                                   cmdline_args)
     };
 
-    if log_enabled!(::log::LogLevel::Debug) {
+    if log_enabled!(::log::Level::Debug) {
         // This only makes sense for ordered stores; note the
         // enumerate to count the number of entries.
         let (entries_less_1, _) = map.iter().filter(|&x| {

src/librustc/mir/mono.rs

@@ -12,9 +12,11 @@ use syntax::ast::NodeId;
 use syntax::symbol::InternedString;
 use ty::Instance;
 use util::nodemap::FxHashMap;
+use rustc_data_structures::base_n;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasherResult,
                                            StableHasher};
 use ich::{Fingerprint, StableHashingContext, NodeIdHashingMode};
+use std::hash::Hash;
 
 #[derive(PartialEq, Eq, Clone, Copy, Debug, Hash)]
 pub enum MonoItem<'tcx> {
@@ -119,6 +121,16 @@ impl<'tcx> CodegenUnit<'tcx> {
     {
         &mut self.items
     }
+
+    pub fn mangle_name(human_readable_name: &str) -> String {
+        // We generate a 80 bit hash from the name. This should be enough to
+        // avoid collisions and is still reasonably short for filenames.
+        let mut hasher = StableHasher::new();
+        human_readable_name.hash(&mut hasher);
+        let hash: u128 = hasher.finish();
+        let hash = hash & ((1u128 << 80) - 1);
+        base_n::encode(hash, base_n::CASE_INSENSITIVE)
+    }
 }
 
 impl<'tcx> HashStable<StableHashingContext<'tcx>> for CodegenUnit<'tcx> {

src/librustc/session/config.rs

@@ -1234,6 +1234,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "rewrite operators on i128 and u128 into lang item calls (typically provided \
          by compiler-builtins) so translation doesn't need to support them,
          overriding the default for the current target"),
+    human_readable_cgu_names: bool = (false, parse_bool, [TRACKED],
+        "generate human-readable, predictable names for codegen units"),
 }
 
 pub fn default_lib_output() -> CrateType {

src/librustc_back/Cargo.toml

@@ -11,7 +11,7 @@ crate-type = ["dylib"]
 [dependencies]
 syntax = { path = "../libsyntax" }
 serialize = { path = "../libserialize" }
-log = "0.3"
+log = "0.4"
 rand = "0.3"
 
 [features]

src/librustc_borrowck/Cargo.toml

@@ -10,7 +10,7 @@ crate-type = ["dylib"]
 test = false
 
 [dependencies]
-log = "0.3"
+log = "0.4"
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
 graphviz = { path = "../libgraphviz" }

src/librustc_const_eval/Cargo.toml

@@ -10,7 +10,7 @@ crate-type = ["dylib"]
 
 [dependencies]
 arena = { path = "../libarena" }
-log = "0.3"
+log = "0.4"
 rustc = { path = "../librustc" }
 rustc_const_math = { path = "../librustc_const_math" }
 rustc_data_structures = { path = "../librustc_data_structures" }

src/librustc_data_structures/Cargo.toml

@@ -9,12 +9,12 @@ path = "lib.rs"
 crate-type = ["dylib"]
 
 [dependencies]
-log = "0.3"
+log = "0.4"
 serialize = { path = "../libserialize" }
 cfg-if = "0.1.2"
 stable_deref_trait = "1.0.0"
 parking_lot_core = "0.2.8"
 
 [dependencies.parking_lot]
 version = "0.5"
-features = ["nightly"]
+features = ["nightly"]