Merge pull request #20 from llvm/main

[pull] main from llvm:main

clang-tools-extra/clang-doc/HTMLGenerator.cpp

@@ -579,8 +579,8 @@ genHTML(const Index &Index, StringRef InfoPath, bool IsOutermostList) {
     if (!Index.JumpToSection)
       SpanBody->Children.emplace_back(genReference(Index, InfoPath));
     else
-      SpanBody->Children.emplace_back(genReference(
-          Index, InfoPath, StringRef{Index.JumpToSection.getValue()}));
+      SpanBody->Children.emplace_back(
+          genReference(Index, InfoPath, Index.JumpToSection.getValue().str()));
   }
   if (Index.Children.empty())
     return Out;

clang-tools-extra/clangd/JSONTransport.cpp

@@ -230,7 +230,7 @@ bool JSONTransport::readStandardMessage(std::string &JSON) {
       return false;
     InMirror << Line;
 
-    llvm::StringRef LineRef(Line);
+    llvm::StringRef LineRef = Line;
 
     // We allow comments in headers. Technically this isn't part
 
@@ -298,7 +298,7 @@ bool JSONTransport::readDelimitedMessage(std::string &JSON) {
   llvm::SmallString<128> Line;
   while (readLine(In, Line)) {
     InMirror << Line;
-    auto LineRef = llvm::StringRef(Line).trim();
+    auto LineRef = Line.str().trim();
     if (LineRef.startswith("#")) // comment
       continue;
 

clang-tools-extra/clangd/QueryDriverDatabase.cpp

@@ -175,8 +175,7 @@ extractSystemIncludesAndTarget(llvm::SmallString<128> Driver,
   auto CleanUp = llvm::make_scope_exit(
       [&StdErrPath]() { llvm::sys::fs::remove(StdErrPath); });
 
-  llvm::Optional<llvm::StringRef> Redirects[] = {
-      {""}, {""}, llvm::StringRef(StdErrPath)};
+  llvm::Optional<llvm::StringRef> Redirects[] = {{""}, {""}, StdErrPath.str()};
 
   llvm::SmallVector<llvm::StringRef> Args = {Driver, "-E", "-x",
                                              Lang,   "-",  "-v"};

clang-tools-extra/clangd/Selection.cpp

@@ -771,8 +771,7 @@ llvm::SmallString<256> abbreviatedString(DynTypedNode N,
   }
   auto Pos = Result.find('\n');
   if (Pos != llvm::StringRef::npos) {
-    bool MoreText =
-        !llvm::all_of(llvm::StringRef(Result).drop_front(Pos), llvm::isSpace);
+    bool MoreText = !llvm::all_of(Result.str().drop_front(Pos), llvm::isSpace);
     Result.resize(Pos);
     if (MoreText)
       Result.append(" …");

clang-tools-extra/clangd/support/Threading.cpp

@@ -3,6 +3,7 @@
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Threading.h"
+#include "llvm/Support/thread.h"
 #include <atomic>
 #include <thread>
 #ifdef __USE_POSIX
@@ -95,8 +96,10 @@ void AsyncTaskRunner::runAsync(const llvm::Twine &Name,
   };
 
   // Ensure our worker threads have big enough stacks to run clang.
-  llvm::llvm_execute_on_thread_async(std::move(Task),
-                                     /*clang::DesiredStackSize*/ 8 << 20);
+  llvm::thread Thread(
+      /*clang::DesiredStackSize*/ llvm::Optional<unsigned>(8 << 20),
+      std::move(Task));
+  Thread.detach();
 }
 
 Deadline timeoutSeconds(llvm::Optional<double> Seconds) {

clang/docs/AddressSanitizer.rst

@@ -14,8 +14,9 @@ following types of bugs:
 
 * Out-of-bounds accesses to heap, stack and globals
 * Use-after-free
-* Use-after-return (runtime flag `ASAN_OPTIONS=detect_stack_use_after_return=1`)
-* Use-after-scope (clang flag `-fsanitize-address-use-after-scope`)
+* Use-after-return (clang flag ``-fsanitize-address-use-after-return=(never|runtime|always)`` default: ``runtime``)
+    * Enable ``runtime`` with: ``ASAN_OPTIONS=detect_stack_use_after_return=1``
+* Use-after-scope (clang flag ``-fsanitize-address-use-after-scope``)
 * Double-free, invalid free
 * Memory leaks (experimental)
 
@@ -136,6 +137,26 @@ you should set environment variable
 
 Note that this option is not supported on macOS.
 
+Stack Use After Return (UAR)
+----------------------------
+
+AddressSanitizer can optionally detect stack use after return problems.
+This is available by default, or explicitly
+(``-fsanitize-address-use-after-return=runtime``).
+To enable this check at runtime, set the environment variable
+``ASAN_OPTIONS=detect_stack_use_after_return=1``.
+
+Enabling this check (``-fsanitize-address-use-after-return=always``) will
+reduce code size.  The code size may be reduced further by completely
+eliminating this check (``-fsanitize-address-use-after-return=never``).
+
+To summarize: ``-fsanitize-address-use-after-return=<mode>``
+  * ``never``: Completely disables detection of UAR errors (reduces code size).
+  * ``runtime``: Adds the code for detection, but must be enabled via the
+    runtime environment (``ASAN_OPTIONS=detect_stack_use_after_return=1``).
+  * ``always``: Enables detection of UAR errors in all cases. (reduces code
+    size, but not as much as ``never``).
+
 Memory leak detection
 ---------------------
 

clang/docs/UsersManual.rst

@@ -3744,6 +3744,8 @@ Execute ``clang-cl /?`` to see a list of supported options:
                               Enable linker dead stripping of globals in AddressSanitizer
       -fsanitize-address-poison-custom-array-cookie
                               Enable poisoning array cookies when using custom operator new[] in AddressSanitizer
+      -fsanitize-address-use-after-return=<mode>
+                              Select the mode of detecting stack use-after-return in AddressSanitizer: never | runtime (default) | always
       -fsanitize-address-use-after-scope
                               Enable use-after-scope detection in AddressSanitizer
       -fsanitize-address-use-odr-indicator

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -6744,13 +6744,13 @@ def ext_typecheck_indirection_through_void_pointer : ExtWarn<
   "ISO C++ does not allow indirection on operand of type %0">,
   InGroup<DiagGroup<"void-ptr-dereference">>;
 def warn_indirection_through_null : Warning<
-  "indirection of non-volatile null pointer will be deleted, not trap">,
+  "indirection of null pointer will be deleted, not trap">,
   InGroup<NullDereference>;
 def warn_binding_null_to_reference : Warning<
   "binding dereferenced null pointer to reference has undefined behavior">,
   InGroup<NullDereference>;
 def note_indirection_through_null : Note<
-  "consider using __builtin_trap() or qualifying pointer with 'volatile'">;
+  "consider using __builtin_trap()">;
 def warn_pointer_indirection_from_incompatible_type : Warning<
   "dereference of type %1 that was reinterpret_cast from type %0 has undefined "
   "behavior">,

clang/include/clang/Driver/Options.td

@@ -1584,7 +1584,7 @@ def sanitize_address_use_after_return_EQ
   : Joined<["-"], "fsanitize-address-use-after-return=">,
     MetaVarName<"<mode>">,
     Flags<[CC1Option]>,
-    HelpText<"Select the mode of detecting stack use-after-return in AddressSanitizer">,
+    HelpText<"Select the mode of detecting stack use-after-return in AddressSanitizer: never | runtime (default) | always">,
     Group<f_clang_Group>,
     Values<"never,runtime,always">,
     NormalizedValuesScope<"llvm::AsanDetectStackUseAfterReturnMode">,

clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h

@@ -65,7 +65,7 @@ class CachedFileSystemEntry {
       return MaybeStat.getError();
     assert(!MaybeStat->isDirectory() && "not a file");
     assert(isValid() && "not initialized");
-    return StringRef(Contents);
+    return Contents.str();
   }
 
   /// \returns The error or the status of the entry.

clang/lib/AST/Expr.cpp

@@ -1913,6 +1913,7 @@ Expr *CastExpr::getSubExprAsWritten() {
       SubExpr =
         skipImplicitTemporary(cast<CXXConstructExpr>(SubExpr->IgnoreImplicit())->getArg(0));
     else if (E->getCastKind() == CK_UserDefinedConversion) {
+      SubExpr = SubExpr->IgnoreImplicit();
       assert((isa<CXXMemberCallExpr>(SubExpr) ||
               isa<BlockExpr>(SubExpr)) &&
              "Unexpected SubExpr for CK_UserDefinedConversion.");

clang/lib/AST/MicrosoftMangle.cpp

@@ -3676,7 +3676,7 @@ void MicrosoftMangleContextImpl::mangleCXXRTTICompleteObjectLocator(
   assert(VFTableMangling.startswith("??_7") ||
          VFTableMangling.startswith("??_S"));
 
-  Out << "??_R4" << StringRef(VFTableMangling).drop_front(4);
+  Out << "??_R4" << VFTableMangling.str().drop_front(4);
 }
 
 void MicrosoftMangleContextImpl::mangleSEHFilterExpression(

clang/lib/Analysis/MacroExpansionContext.cpp

@@ -111,7 +111,7 @@ MacroExpansionContext::getExpandedText(SourceLocation MacroExpansionLoc) const {
     return StringRef{""};
 
   // Otherwise we have the actual token sequence as string.
-  return StringRef{It->getSecond()};
+  return It->getSecond().str();
 }
 
 Optional<StringRef>

clang/lib/Basic/FileManager.cpp

@@ -611,7 +611,7 @@ StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) {
 
   SmallString<4096> CanonicalNameBuf;
   if (!FS->getRealPath(Dir->getName(), CanonicalNameBuf))
-    CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
+    CanonicalName = CanonicalNameBuf.str().copy(CanonicalNameStorage);
 
   CanonicalNames.insert({Dir, CanonicalName});
   return CanonicalName;
@@ -627,7 +627,7 @@ StringRef FileManager::getCanonicalName(const FileEntry *File) {
 
   SmallString<4096> CanonicalNameBuf;
   if (!FS->getRealPath(File->getName(), CanonicalNameBuf))
-    CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
+    CanonicalName = CanonicalNameBuf.str().copy(CanonicalNameStorage);
 
   CanonicalNames.insert({File, CanonicalName});
   return CanonicalName;

clang/lib/CodeGen/CGCall.cpp

@@ -1012,8 +1012,8 @@ static void forConstantArrayExpansion(CodeGenFunction &CGF,
     BaseAddr.getAlignment().alignmentOfArrayElement(EltSize);
 
   for (int i = 0, n = CAE->NumElts; i < n; i++) {
-    llvm::Value *EltAddr =
-      CGF.Builder.CreateConstGEP2_32(nullptr, BaseAddr.getPointer(), 0, i);
+    llvm::Value *EltAddr = CGF.Builder.CreateConstGEP2_32(
+        BaseAddr.getElementType(), BaseAddr.getPointer(), 0, i);
     Fn(Address(EltAddr, EltAlign));
   }
 }
@@ -3437,7 +3437,8 @@ void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
       --EI;
       llvm::Value *ArgStruct = &*EI;
       llvm::Value *SRet = Builder.CreateStructGEP(
-          nullptr, ArgStruct, RetAI.getInAllocaFieldIndex());
+          EI->getType()->getPointerElementType(), ArgStruct,
+          RetAI.getInAllocaFieldIndex());
       llvm::Type *Ty =
           cast<llvm::GetElementPtrInst>(SRet)->getResultElementType();
       RV = Builder.CreateAlignedLoad(Ty, SRet, getPointerAlign(), "sret");

clang/lib/CodeGen/CGObjCGNU.cpp

@@ -739,9 +739,11 @@ class CGObjCGNUstep : public CGObjCGNU {
     /// Function to perform atomic copies of C++ objects with nontrivial copy
     /// constructors to Objective-C ivars.
     LazyRuntimeFunction CxxAtomicObjectSetFn;
-    /// Type of an slot structure pointer.  This is returned by the various
+    /// Type of a slot structure pointer.  This is returned by the various
     /// lookup functions.
     llvm::Type *SlotTy;
+    /// Type of a slot structure.
+    llvm::Type *SlotStructTy;
 
   public:
     llvm::Constant *GetEHType(QualType T) override;
@@ -780,7 +782,7 @@ class CGObjCGNUstep : public CGObjCGNU {
 
       // Load the imp from the slot
       llvm::Value *imp = Builder.CreateAlignedLoad(
-          IMPTy, Builder.CreateStructGEP(nullptr, slot, 4),
+          IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
           CGF.getPointerAlign());
 
       // The lookup function may have changed the receiver, so make sure we use
@@ -800,7 +802,7 @@ class CGObjCGNUstep : public CGObjCGNU {
       slot->setOnlyReadsMemory();
 
       return Builder.CreateAlignedLoad(
-          IMPTy, Builder.CreateStructGEP(nullptr, slot, 4),
+          IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
           CGF.getPointerAlign());
     }
 
@@ -811,8 +813,7 @@ class CGObjCGNUstep : public CGObjCGNU {
       CGObjCGNU(Mod, ABI, ProtocolABI, ClassABI) {
       const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
 
-      llvm::StructType *SlotStructTy =
-          llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
+      SlotStructTy = llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
       SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
       // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
       SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,

clang/lib/CodeGen/CGStmtOpenMP.cpp

@@ -786,6 +786,9 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
                                                 OMPPrivateScope &PrivateScope) {
   if (!HaveInsertPoint())
     return false;
+  bool DeviceConstTarget =
+      getLangOpts().OpenMPIsDevice &&
+      isOpenMPTargetExecutionDirective(D.getDirectiveKind());
   bool FirstprivateIsLastprivate = false;
   llvm::DenseMap<const VarDecl *, OpenMPLastprivateModifier> Lastprivates;
   for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
@@ -818,6 +821,16 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
         ++InitsRef;
         continue;
       }
+      // Do not emit copy for firstprivate constant variables in target regions,
+      // captured by reference.
+      if (DeviceConstTarget && OrigVD->getType().isConstant(getContext()) &&
+          FD && FD->getType()->isReferenceType() &&
+          (!VD || !VD->hasAttr<OMPAllocateDeclAttr>())) {
+        EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl());
+        ++IRef;
+        ++InitsRef;
+        continue;
+      }
       FirstprivateIsLastprivate =
           FirstprivateIsLastprivate || ThisFirstprivateIsLastprivate;
       if (EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl()).second) {

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -1084,7 +1084,8 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
     unsigned Idx = CurFnInfo->getReturnInfo().getInAllocaFieldIndex();
     llvm::Function::arg_iterator EI = CurFn->arg_end();
     --EI;
-    llvm::Value *Addr = Builder.CreateStructGEP(nullptr, &*EI, Idx);
+    llvm::Value *Addr = Builder.CreateStructGEP(
+        EI->getType()->getPointerElementType(), &*EI, Idx);
     llvm::Type *Ty =
         cast<llvm::GetElementPtrInst>(Addr)->getResultElementType();
     ReturnValuePointer = Address(Addr, getPointerAlign());

clang/lib/CodeGen/ItaniumCXXABI.cpp

@@ -1535,7 +1535,7 @@ llvm::Value *ItaniumCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF,
 
     // Get the offset-to-top from the vtable.
     OffsetToTop =
-        CGF.Builder.CreateConstInBoundsGEP1_32(/*Type=*/nullptr, VTable, -2U);
+        CGF.Builder.CreateConstInBoundsGEP1_32(CGM.Int32Ty, VTable, -2U);
     OffsetToTop = CGF.Builder.CreateAlignedLoad(
         CGM.Int32Ty, OffsetToTop, CharUnits::fromQuantity(4), "offset.to.top");
   } else {

clang/lib/CodeGen/MicrosoftCXXABI.cpp

@@ -4338,7 +4338,7 @@ llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
   };
   auto *GV = new llvm::GlobalVariable(
       CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
-      llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
+      llvm::ConstantStruct::get(TIType, Fields), MangledName.str());
   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
   GV->setSection(".xdata");
   if (GV->isWeakForLinker())

clang/lib/CrossTU/CrossTranslationUnit.cpp

@@ -634,7 +634,7 @@ parseInvocationList(StringRef FileContent, llvm::sys::path::Style PathStyle) {
     SmallString<32> NativeSourcePath(SourcePath);
     llvm::sys::path::native(NativeSourcePath, PathStyle);
 
-    StringRef InvocationKey(NativeSourcePath);
+    StringRef InvocationKey = NativeSourcePath;
 
     if (InvocationList.find(InvocationKey) != InvocationList.end())
       return llvm::make_error<IndexError>(

clang/lib/Driver/ToolChains/AMDGPU.cpp

@@ -748,7 +748,7 @@ AMDGPUToolChain::detectSystemGPUs(const ArgList &Args,
   llvm::FileRemover OutputRemover(OutputFile.c_str());
   llvm::Optional<llvm::StringRef> Redirects[] = {
       {""},
-      StringRef(OutputFile),
+      OutputFile.str(),
       {""},
   };
 

clang/lib/Lex/HeaderSearch.cpp

@@ -727,7 +727,7 @@ diagnoseFrameworkInclude(DiagnosticsEngine &Diags, SourceLocation IncludeLoc,
   if (!isAngled && !FoundByHeaderMap) {
     SmallString<128> NewInclude("<");
     if (IsIncludeeInFramework) {
-      NewInclude += StringRef(ToFramework).drop_back(10); // drop .framework
+      NewInclude += ToFramework.str().drop_back(10); // drop .framework
       NewInclude += "/";
     }
     NewInclude += IncludeFilename;

clang/lib/Lex/PPDirectives.cpp

@@ -1480,7 +1480,7 @@ void Preprocessor::HandleUserDiagnosticDirective(Token &Tok,
 
   // Find the first non-whitespace character, so that we can make the
   // diagnostic more succinct.
-  StringRef Msg = StringRef(Message).ltrim(' ');
+  StringRef Msg = Message.str().ltrim(' ');
 
   if (isWarning)
     Diag(Tok, diag::pp_hash_warning) << Msg;

clang/lib/Sema/SemaExpr.cpp

@@ -533,21 +533,16 @@ ExprResult Sema::DefaultFunctionArrayConversion(Expr *E, bool Diagnose) {
 }
 
 static void CheckForNullPointerDereference(Sema &S, Expr *E) {
-  // Check to see if we are dereferencing a null pointer.  If so,
-  // and if not volatile-qualified, this is undefined behavior that the
-  // optimizer will delete, so warn about it.  People sometimes try to use this
-  // to get a deterministic trap and are surprised by clang's behavior.  This
-  // only handles the pattern "*null", which is a very syntactic check.
+  // Check to see if we are dereferencing a null pointer.
+  // If so, this is undefined behavior that the optimizer will delete,
+  // so warn about it. People sometimes try to use this to get a deterministic
+  // trap and are surprised by clang's behavior. This only handles the pattern
+  // "*null", which is a very syntactic check.
   const auto *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts());
   if (UO && UO->getOpcode() == UO_Deref &&
       UO->getSubExpr()->getType()->isPointerType()) {
-    const LangAS AS =
-        UO->getSubExpr()->getType()->getPointeeType().getAddressSpace();
-    if ((!isTargetAddressSpace(AS) ||
-         (isTargetAddressSpace(AS) && toTargetAddressSpace(AS) == 0)) &&
-        UO->getSubExpr()->IgnoreParenCasts()->isNullPointerConstant(
-            S.Context, Expr::NPC_ValueDependentIsNotNull) &&
-        !UO->getType().isVolatileQualified()) {
+    if (UO->getSubExpr()->IgnoreParenCasts()->isNullPointerConstant(
+            S.Context, Expr::NPC_ValueDependentIsNotNull)) {
       S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
                             S.PDiag(diag::warn_indirection_through_null)
                                 << UO->getSubExpr()->getSourceRange());

clang/lib/Sema/SemaExprCXX.cpp

@@ -7786,7 +7786,7 @@ ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
                         Method->getType()->castAs<FunctionProtoType>()))
     return ExprError();
 
-  return CE;
+  return CheckForImmediateInvocation(CE, CE->getMethodDecl());
 }
 
 ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
@@ -8343,6 +8343,7 @@ class TransformTypos : public TreeTransform<TransformTypos> {
 
         AmbiguousTypoExprs.remove(TE);
         SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition();
+        TransformCache[TE] = SavedTransformCache[TE];
       }
       TransformCache = std::move(SavedTransformCache);
     }