Auto merge of rust-lang#122117 - matthiaskrgr:rollup-3yrv3j6, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#122015 (Add better explanation for `rustc_index::IndexVec`)
 - rust-lang#122061 (Clarify FatalErrorHandler)
 - rust-lang#122062 (Explicitly assign constructed C++ classes)
 - rust-lang#122072 (Refer to "slice" instead of "vector" in Ord and PartialOrd trait impl of slices)
 - rust-lang#122088 (Remove unnecessary fixme on new thread stack size)
 - rust-lang#122094 (Remove outdated footnote "missing-stack-probe" in platform-support)
 - rust-lang#122107 (Temporarily make allow-by-default the `non_local_definitions` lint)
 - rust-lang#122109 (compiletest: Add a `//@ needs-threads` directive)

Failed merges:

 - rust-lang#122104 (Rust is a proper name: rust → Rust)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_index/src/vec.rs

@@ -12,7 +12,24 @@ use std::vec;
 use crate::{Idx, IndexSlice};
 
 /// An owned contiguous collection of `T`s, indexed by `I` rather than by `usize`.
-/// Its purpose is to avoid mixing indexes.
+///
+/// ## Why use this instead of a `Vec`?
+///
+/// An `IndexVec` allows element access only via a specific associated index type, meaning that
+/// trying to use the wrong index type (possibly accessing an invalid element) will fail at
+/// compile time.
+///
+/// It also documents what the index is indexing: in a `HashMap<usize, Something>` it's not
+/// immediately clear what the `usize` means, while a `HashMap<FieldIdx, Something>` makes it obvious.
+///
+/// ```compile_fail
+/// use rustc_index::{Idx, IndexVec};
+///
+/// fn f<I1: Idx, I2: Idx>(vec1: IndexVec<I1, u8>, idx1: I1, idx2: I2) {
+///   &vec1[idx1]; // Ok
+///   &vec1[idx2]; // Compile error!
+/// }
+/// ```
 ///
 /// While it's possible to use `u32` or `usize` directly for `I`,
 /// you almost certainly want to use a [`newtype_index!`]-generated type instead.

compiler/rustc_lint/src/non_local_def.rs

@@ -14,6 +14,7 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust
+    /// #![warn(non_local_definitions)]
     /// trait MyTrait {}
     /// struct MyStruct;
     ///
@@ -36,7 +37,7 @@ declare_lint! {
     /// All nested bodies (functions, enum discriminant, array length, consts) (expect for
     /// `const _: Ty = { ... }` in top-level module, which is still undecided) are checked.
     pub NON_LOCAL_DEFINITIONS,
-    Warn,
+    Allow,
     "checks for non-local definitions",
     report_in_external_macro
 }

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -120,7 +120,7 @@ extern "C" void LLVMRustCoverageWriteFilenamesSectionToBuffer(
   }
   auto FilenamesWriter =
       coverage::CoverageFilenamesSectionWriter(ArrayRef<std::string>(FilenameRefs));
-  RawRustStringOstream OS(BufferOut);
+  auto OS = RawRustStringOstream(BufferOut);
   FilenamesWriter.write(OS);
 }
 
@@ -160,31 +160,31 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
       ArrayRef<unsigned>(VirtualFileMappingIDs, NumVirtualFileMappingIDs),
       Expressions,
       MappingRegions);
-  RawRustStringOstream OS(BufferOut);
+  auto OS = RawRustStringOstream(BufferOut);
   CoverageMappingWriter.write(OS);
 }
 
 extern "C" LLVMValueRef LLVMRustCoverageCreatePGOFuncNameVar(
     LLVMValueRef F,
     const char *FuncName,
     size_t FuncNameLen) {
-  StringRef FuncNameRef(FuncName, FuncNameLen);
+  auto FuncNameRef = StringRef(FuncName, FuncNameLen);
   return wrap(createPGOFuncNameVar(*cast<Function>(unwrap(F)), FuncNameRef));
 }
 
 extern "C" uint64_t LLVMRustCoverageHashByteArray(
     const char *Bytes,
     size_t NumBytes) {
-  StringRef StrRef(Bytes, NumBytes);
+  auto StrRef = StringRef(Bytes, NumBytes);
   return IndexedInstrProf::ComputeHash(StrRef);
 }
 
 static void WriteSectionNameToString(LLVMModuleRef M,
                                      InstrProfSectKind SK,
                                      RustStringRef Str) {
-  Triple TargetTriple(unwrap(M)->getTargetTriple());
+  auto TargetTriple = Triple(unwrap(M)->getTargetTriple());
   auto name = getInstrProfSectionName(SK, TargetTriple.getObjectFormat());
-  RawRustStringOstream OS(Str);
+  auto OS = RawRustStringOstream(Str);
   OS << name;
 }
 
@@ -200,7 +200,7 @@ extern "C" void LLVMRustCoverageWriteFuncSectionNameToString(LLVMModuleRef M,
 
 extern "C" void LLVMRustCoverageWriteMappingVarNameToString(RustStringRef Str) {
   auto name = getCoverageMappingVarName();
-  RawRustStringOstream OS(Str);
+  auto OS = RawRustStringOstream(Str);
   OS << name;
 }
 

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -77,9 +77,9 @@ extern "C" void LLVMRustTimeTraceProfilerFinishThread() {
 }
 
 extern "C" void LLVMRustTimeTraceProfilerFinish(const char* FileName) {
-  StringRef FN(FileName);
+  auto FN = StringRef(FileName);
   std::error_code EC;
-  raw_fd_ostream OS(FN, EC, sys::fs::CD_CreateAlways);
+  auto OS = raw_fd_ostream(FN, EC, sys::fs::CD_CreateAlways);
 
   timeTraceProfilerWrite(OS);
   timeTraceProfilerCleanup();
@@ -424,7 +424,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   auto CM = fromRust(RustCM);
 
   std::string Error;
-  Triple Trip(Triple::normalize(TripleStr));
+  auto Trip = Triple(Triple::normalize(TripleStr));
   const llvm::Target *TheTarget =
       TargetRegistry::lookupTarget(Trip.getTriple(), Error);
   if (TheTarget == nullptr) {
@@ -537,8 +537,8 @@ extern "C" void LLVMRustDisposeTargetMachine(LLVMTargetMachineRef TM) {
 // TargetLibraryInfo pass, so we use this method to do so.
 extern "C" void LLVMRustAddLibraryInfo(LLVMPassManagerRef PMR, LLVMModuleRef M,
                                        bool DisableSimplifyLibCalls) {
-  Triple TargetTriple(unwrap(M)->getTargetTriple());
-  TargetLibraryInfoImpl TLII(TargetTriple);
+  auto TargetTriple = Triple(unwrap(M)->getTargetTriple());
+  auto TLII = TargetLibraryInfoImpl(TargetTriple);
   if (DisableSimplifyLibCalls)
     TLII.disableAllFunctions();
   unwrap(PMR)->add(new TargetLibraryInfoWrapperPass(TLII));
@@ -589,25 +589,25 @@ LLVMRustWriteOutputFile(LLVMTargetMachineRef Target, LLVMPassManagerRef PMR,
 
   std::string ErrorInfo;
   std::error_code EC;
-  raw_fd_ostream OS(Path, EC, sys::fs::OF_None);
+  auto OS = raw_fd_ostream(Path, EC, sys::fs::OF_None);
   if (EC)
     ErrorInfo = EC.message();
   if (ErrorInfo != "") {
     LLVMRustSetLastError(ErrorInfo.c_str());
     return LLVMRustResult::Failure;
   }
 
-  buffer_ostream BOS(OS);
+  auto BOS = buffer_ostream(OS);
   if (DwoPath) {
-    raw_fd_ostream DOS(DwoPath, EC, sys::fs::OF_None);
+    auto DOS = raw_fd_ostream(DwoPath, EC, sys::fs::OF_None);
     EC.clear();
     if (EC)
         ErrorInfo = EC.message();
     if (ErrorInfo != "") {
       LLVMRustSetLastError(ErrorInfo.c_str());
       return LLVMRustResult::Failure;
     }
-    buffer_ostream DBOS(DOS);
+    auto DBOS = buffer_ostream(DOS);
     unwrap(Target)->addPassesToEmitFile(*PM, BOS, &DBOS, FileType, false);
     PM->run(*unwrap(M));
   } else {
@@ -796,7 +796,7 @@ LLVMRustOptimize(
                         DebugInfoForProfiling);
   }
 
-  PassBuilder PB(TM, PTO, PGOOpt, &PIC);
+  auto PB = PassBuilder(TM, PTO, PGOOpt, &PIC);
   LoopAnalysisManager LAM;
   FunctionAnalysisManager FAM;
   CGSCCAnalysisManager CGAM;
@@ -1112,16 +1112,16 @@ extern "C" LLVMRustResult
 LLVMRustPrintModule(LLVMModuleRef M, const char *Path, DemangleFn Demangle) {
   std::string ErrorInfo;
   std::error_code EC;
-  raw_fd_ostream OS(Path, EC, sys::fs::OF_None);
+  auto OS = raw_fd_ostream(Path, EC, sys::fs::OF_None);
   if (EC)
     ErrorInfo = EC.message();
   if (ErrorInfo != "") {
     LLVMRustSetLastError(ErrorInfo.c_str());
     return LLVMRustResult::Failure;
   }
 
-  RustAssemblyAnnotationWriter AAW(Demangle);
-  formatted_raw_ostream FOS(OS);
+  auto AAW = RustAssemblyAnnotationWriter(Demangle);
+  auto FOS = formatted_raw_ostream(OS);
   unwrap(M)->print(FOS, &AAW);
 
   return LLVMRustResult::Success;
@@ -1281,8 +1281,8 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
   // Load each module's summary and merge it into one combined index
   for (int i = 0; i < num_modules; i++) {
     auto module = &modules[i];
-    StringRef buffer(module->data, module->len);
-    MemoryBufferRef mem_buffer(buffer, module->identifier);
+    auto buffer = StringRef(module->data, module->len);
+    auto mem_buffer = MemoryBufferRef(buffer, module->identifier);
 
     Ret->ModuleMap[module->identifier] = mem_buffer;
 
@@ -1485,7 +1485,7 @@ LLVMRustPrepareThinLTOImport(const LLVMRustThinLTOData *Data, LLVMModuleRef M,
     return MOrErr;
   };
   bool ClearDSOLocal = clearDSOLocalOnDeclarations(Mod, Target);
-  FunctionImporter Importer(Data->Index, Loader, ClearDSOLocal);
+  auto Importer = FunctionImporter(Data->Index, Loader, ClearDSOLocal);
   Expected<bool> Result = Importer.importFunctions(Mod, ImportList);
   if (!Result) {
     LLVMRustSetLastError(toString(Result.takeError()).c_str());
@@ -1510,7 +1510,7 @@ extern "C" LLVMRustThinLTOBuffer*
 LLVMRustThinLTOBufferCreate(LLVMModuleRef M, bool is_thin) {
   auto Ret = std::make_unique<LLVMRustThinLTOBuffer>();
   {
-    raw_string_ostream OS(Ret->data);
+    auto OS = raw_string_ostream(Ret->data);
     {
       if (is_thin) {
         PassBuilder PB;
@@ -1557,8 +1557,8 @@ LLVMRustParseBitcodeForLTO(LLVMContextRef Context,
                            const char *data,
                            size_t len,
                            const char *identifier) {
-  StringRef Data(data, len);
-  MemoryBufferRef Buffer(Data, identifier);
+  auto Data = StringRef(data, len);
+  auto Buffer = MemoryBufferRef(Data, identifier);
   unwrap(Context)->enableDebugTypeODRUniquing();
   Expected<std::unique_ptr<Module>> SrcOrError =
       parseBitcodeFile(Buffer, *unwrap(Context));
@@ -1576,8 +1576,8 @@ extern "C" const char *LLVMRustGetSliceFromObjectDataByName(const char *data,
                                                             const char *name,
                                                             size_t *out_len) {
   *out_len = 0;
-  StringRef Data(data, len);
-  MemoryBufferRef Buffer(Data, ""); // The id is unused.
+  auto Data = StringRef(data, len);
+  auto Buffer = MemoryBufferRef(Data, ""); // The id is unused.
   file_magic Type = identify_magic(Buffer.getBuffer());
   Expected<std::unique_ptr<object::ObjectFile>> ObjFileOrError =
       object::ObjectFile::createObjectFile(Buffer, Type);