Merge branch 'main' into amd/dev/tnowicki/coro-docs-parameter-attribs

Author: Tyler Nowicki

bolt/lib/Core/BinaryEmitter.cpp

@@ -416,17 +416,6 @@ void BinaryEmitter::emitFunctionBody(BinaryFunction &BF, FunctionFragment &FF,
     BF.duplicateConstantIslands();
   }
 
-  if (!FF.empty() && FF.front()->isLandingPad()) {
-    assert(!FF.front()->isEntryPoint() &&
-           "Landing pad cannot be entry point of function");
-    // If the first block of the fragment is a landing pad, it's offset from the
-    // start of the area that the corresponding LSDA describes is zero. In this
-    // case, the call site entries in that LSDA have 0 as offset to the landing
-    // pad, which the runtime interprets as "no handler". To prevent this,
-    // insert some padding.
-    Streamer.emitBytes(BC.MIB->getTrapFillValue());
-  }
-
   // Track the first emitted instruction with debug info.
   bool FirstInstr = true;
   for (BinaryBasicBlock *const BB : FF) {
@@ -926,39 +915,54 @@ void BinaryEmitter::emitLSDA(BinaryFunction &BF, const FunctionFragment &FF) {
   // Emit the LSDA header.
 
   // If LPStart is omitted, then the start of the FDE is used as a base for
-  // landing pad displacements. Then if a cold fragment starts with
-  // a landing pad, this means that the first landing pad offset will be 0.
-  // As a result, the exception handling runtime will ignore this landing pad
-  // because zero offset denotes the absence of a landing pad.
-  // For this reason, when the binary has fixed starting address we emit LPStart
-  // as 0 and output the absolute value of the landing pad in the table.
+  // landing pad displacements. Then, if a cold fragment starts with a landing
+  // pad, this means that the first landing pad offset will be 0. However, C++
+  // runtime treats 0 as if there is no landing pad present, thus we *must* emit
+  // non-zero offsets for all valid LPs.
   //
-  // If the base address can change, we cannot use absolute addresses for
-  // landing pads (at least not without runtime relocations). Hence, we fall
-  // back to emitting landing pads relative to the FDE start.
-  // As we are emitting label differences, we have to guarantee both labels are
-  // defined in the same section and hence cannot place the landing pad into a
-  // cold fragment when the corresponding call site is in the hot fragment.
-  // Because of this issue and the previously described issue of possible
-  // zero-offset landing pad we have to place landing pads in the same section
-  // as the corresponding invokes for shared objects.
+  // As a solution, for fixed-address binaries we set LPStart to 0, and for
+  // position-independent binaries we set LP start to FDE start minus one byte
+  // for FDEs that start with a landing pad.
+  const bool NeedsLPAdjustment = !FF.empty() && FF.front()->isLandingPad();
   std::function<void(const MCSymbol *)> emitLandingPad;
   if (BC.HasFixedLoadAddress) {
     Streamer.emitIntValue(dwarf::DW_EH_PE_udata4, 1); // LPStart format
     Streamer.emitIntValue(0, 4);                      // LPStart
     emitLandingPad = [&](const MCSymbol *LPSymbol) {
-      if (!LPSymbol)
-        Streamer.emitIntValue(0, 4);
-      else
+      if (LPSymbol)
         Streamer.emitSymbolValue(LPSymbol, 4);
+      else
+        Streamer.emitIntValue(0, 4);
     };
   } else {
-    Streamer.emitIntValue(dwarf::DW_EH_PE_omit, 1); // LPStart format
+    if (NeedsLPAdjustment) {
+      // Use relative LPStart format and emit LPStart as [SymbolStart - 1].
+      Streamer.emitIntValue(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4, 1);
+      MCSymbol *DotSymbol = BC.Ctx->createTempSymbol("LPBase");
+      Streamer.emitLabel(DotSymbol);
+
+      const MCExpr *LPStartExpr = MCBinaryExpr::createSub(
+          MCSymbolRefExpr::create(StartSymbol, *BC.Ctx),
+          MCSymbolRefExpr::create(DotSymbol, *BC.Ctx), *BC.Ctx);
+      LPStartExpr = MCBinaryExpr::createSub(
+          LPStartExpr, MCConstantExpr::create(1, *BC.Ctx), *BC.Ctx);
+      Streamer.emitValue(LPStartExpr, 4);
+    } else {
+      // DW_EH_PE_omit means FDE start (StartSymbol) will be used as LPStart.
+      Streamer.emitIntValue(dwarf::DW_EH_PE_omit, 1);
+    }
     emitLandingPad = [&](const MCSymbol *LPSymbol) {
-      if (!LPSymbol)
-        Streamer.emitIntValue(0, 4);
-      else
-        Streamer.emitAbsoluteSymbolDiff(LPSymbol, StartSymbol, 4);
+      if (LPSymbol) {
+        const MCExpr *LPOffsetExpr = MCBinaryExpr::createSub(
+            MCSymbolRefExpr::create(LPSymbol, *BC.Ctx),
+            MCSymbolRefExpr::create(StartSymbol, *BC.Ctx), *BC.Ctx);
+        if (NeedsLPAdjustment)
+          LPOffsetExpr = MCBinaryExpr::createAdd(
+              LPOffsetExpr, MCConstantExpr::create(1, *BC.Ctx), *BC.Ctx);
+        Streamer.emitULEB128Value(LPOffsetExpr);
+      } else {
+        Streamer.emitULEB128IntValue(0);
+      }
     };
   }
 
@@ -972,10 +976,12 @@ void BinaryEmitter::emitLSDA(BinaryFunction &BF, const FunctionFragment &FF) {
     Streamer.emitLabel(TTBaseRefLabel);
   }
 
-  // Emit the landing pad call site table. We use signed data4 since we can emit
-  // a landing pad in a different part of the split function that could appear
-  // earlier in the address space than LPStart.
-  Streamer.emitIntValue(dwarf::DW_EH_PE_sdata4, 1);
+  // Emit encoding of entries in the call site table. The format is used for the
+  // call site start, length, and corresponding landing pad.
+  if (BC.HasFixedLoadAddress)
+    Streamer.emitIntValue(dwarf::DW_EH_PE_sdata4, 1);
+  else
+    Streamer.emitIntValue(dwarf::DW_EH_PE_uleb128, 1);
 
   MCSymbol *CSTStartLabel = BC.Ctx->createTempSymbol("CSTStart");
   MCSymbol *CSTEndLabel = BC.Ctx->createTempSymbol("CSTEnd");
@@ -992,8 +998,13 @@ void BinaryEmitter::emitLSDA(BinaryFunction &BF, const FunctionFragment &FF) {
 
     // Start of the range is emitted relative to the start of current
     // function split part.
-    Streamer.emitAbsoluteSymbolDiff(BeginLabel, StartSymbol, 4);
-    Streamer.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 4);
+    if (BC.HasFixedLoadAddress) {
+      Streamer.emitAbsoluteSymbolDiff(BeginLabel, StartSymbol, 4);
+      Streamer.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 4);
+    } else {
+      Streamer.emitAbsoluteSymbolDiffAsULEB128(BeginLabel, StartSymbol);
+      Streamer.emitAbsoluteSymbolDiffAsULEB128(EndLabel, BeginLabel);
+    }
     emitLandingPad(CallSite.LP);
     Streamer.emitULEB128IntValue(CallSite.Action);
   }

clang-tools-extra/clang-include-fixer/IncludeFixer.cpp

@@ -95,7 +95,8 @@ bool IncludeFixerActionFactory::runInvocation(
 
   // Create the compiler's actual diagnostics engine. We want to drop all
   // diagnostics here.
-  Compiler.createDiagnostics(new clang::IgnoringDiagConsumer,
+  Compiler.createDiagnostics(Files->getVirtualFileSystem(),
+                             new clang::IgnoringDiagConsumer,
                              /*ShouldOwnClient=*/true);
   Compiler.createSourceManager(*Files);
 

clang-tools-extra/clang-tidy/modernize/UseStdPrintCheck.cpp

@@ -23,7 +23,7 @@ AST_MATCHER(StringLiteral, isOrdinary) { return Node.isOrdinary(); }
 } // namespace
 
 UseStdPrintCheck::UseStdPrintCheck(StringRef Name, ClangTidyContext *Context)
-    : ClangTidyCheck(Name, Context),
+    : ClangTidyCheck(Name, Context), PP(nullptr),
       StrictMode(Options.getLocalOrGlobal("StrictMode", false)),
       PrintfLikeFunctions(utils::options::parseStringList(
           Options.get("PrintfLikeFunctions", ""))),
@@ -131,6 +131,7 @@ void UseStdPrintCheck::check(const MatchFinder::MatchResult &Result) {
   utils::FormatStringConverter::Configuration ConverterConfig;
   ConverterConfig.StrictMode = StrictMode;
   ConverterConfig.AllowTrailingNewlineRemoval = true;
+  assert(PP && "Preprocessor should be set by registerPPCallbacks");
   utils::FormatStringConverter Converter(
       Result.Context, Printf, FormatArgOffset, ConverterConfig, getLangOpts(),
       *Result.SourceManager, *PP);

clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp

@@ -320,6 +320,12 @@ bool isQualificationConvertiblePointer(QualType From, QualType To,
 } // namespace
 
 static bool canThrow(const FunctionDecl *Func) {
+  // consteval specifies that every call to the function must produce a
+  // compile-time constant, which cannot evaluate a throw expression without
+  // producing a compilation error.
+  if (Func->isConsteval())
+    return false;
+
   const auto *FunProto = Func->getType()->getAs<FunctionProtoType>();
   if (!FunProto)
     return true;

clang-tools-extra/clangd/Compiler.cpp

@@ -110,8 +110,8 @@ buildCompilerInvocation(const ParseInputs &Inputs, clang::DiagnosticConsumer &D,
   CIOpts.VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   CIOpts.CC1Args = CC1Args;
   CIOpts.RecoverOnError = true;
-  CIOpts.Diags =
-      CompilerInstance::createDiagnostics(new DiagnosticOptions, &D, false);
+  CIOpts.Diags = CompilerInstance::createDiagnostics(
+      *CIOpts.VFS, new DiagnosticOptions, &D, false);
   CIOpts.ProbePrecompiled = false;
   std::unique_ptr<CompilerInvocation> CI = createInvocation(ArgStrs, CIOpts);
   if (!CI)
@@ -148,7 +148,7 @@ prepareCompilerInstance(std::unique_ptr<clang::CompilerInvocation> CI,
   auto Clang = std::make_unique<CompilerInstance>(
       std::make_shared<PCHContainerOperations>());
   Clang->setInvocation(std::move(CI));
-  Clang->createDiagnostics(&DiagsClient, false);
+  Clang->createDiagnostics(*VFS, &DiagsClient, false);
 
   if (auto VFSWithRemapping = createVFSFromCompilerInvocation(
           Clang->getInvocation(), Clang->getDiagnostics(), VFS))

clang-tools-extra/clangd/ModulesBuilder.cpp

@@ -188,7 +188,8 @@ bool IsModuleFileUpToDate(PathRef ModuleFilePath,
 
   clang::clangd::IgnoreDiagnostics IgnoreDiags;
   IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
-      CompilerInstance::createDiagnostics(new DiagnosticOptions, &IgnoreDiags,
+      CompilerInstance::createDiagnostics(*VFS, new DiagnosticOptions,
+                                          &IgnoreDiags,
                                           /*ShouldOwnClient=*/false);
 
   LangOptions LangOpts;

clang-tools-extra/clangd/Preamble.cpp

@@ -613,8 +613,9 @@ buildPreamble(PathRef FileName, CompilerInvocation CI,
         for (const auto &L : ASTListeners)
           L->sawDiagnostic(D, Diag);
       });
+  auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   llvm::IntrusiveRefCntPtr<DiagnosticsEngine> PreambleDiagsEngine =
-      CompilerInstance::createDiagnostics(&CI.getDiagnosticOpts(),
+      CompilerInstance::createDiagnostics(*VFS, &CI.getDiagnosticOpts(),
                                           &PreambleDiagnostics,
                                           /*ShouldOwnClient=*/false);
   const Config &Cfg = Config::current();
@@ -651,7 +652,6 @@ buildPreamble(PathRef FileName, CompilerInvocation CI,
         for (const auto &L : ASTListeners)
           L->beforeExecute(CI);
       });
-  auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   llvm::SmallString<32> AbsFileName(FileName);
   VFS->makeAbsolute(AbsFileName);
   auto StatCache = std::make_shared<PreambleFileStatusCache>(AbsFileName);

clang-tools-extra/clangd/refactor/tweaks/DefineOutline.cpp

@@ -239,6 +239,8 @@ getFunctionSourceCode(const FunctionDecl *FD, const DeclContext *TargetContext,
           return;
 
         for (const NamedDecl *ND : Ref.Targets) {
+          if (ND->getKind() == Decl::TemplateTypeParm)
+            return;
           if (ND->getDeclContext() != Ref.Targets.front()->getDeclContext()) {
             elog("Targets from multiple contexts: {0}, {1}",
                  printQualifiedName(*Ref.Targets.front()),

clang-tools-extra/clangd/unittests/tweaks/DefineOutlineTests.cpp

@@ -411,29 +411,29 @@ inline typename O1<T, U...>::template O2<V, A>::E O1<T, U...>::template O2<V, A>
           R"cpp(
             struct Foo {
               template <typename T, bool B = true>
-              void ^bar() {}
+              T ^bar() { return {}; }
             };)cpp",
           R"cpp(
             struct Foo {
               template <typename T, bool B = true>
-              void bar() ;
+              T bar() ;
             };template <typename T, bool B>
-inline void Foo::bar() {}
+inline T Foo::bar() { return {}; }
 )cpp",
           ""},
 
       // Class template with member template
       {
           R"cpp(
             template <typename T> struct Foo {
-              template <typename U> void ^bar(const T& t, const U& u) {}
+              template <typename U> T ^bar(const T& t, const U& u) { return {}; }
             };)cpp",
           R"cpp(
             template <typename T> struct Foo {
-              template <typename U> void bar(const T& t, const U& u) ;
+              template <typename U> T bar(const T& t, const U& u) ;
             };template <typename T>
 template <typename U>
-inline void Foo<T>::bar(const T& t, const U& u) {}
+inline T Foo<T>::bar(const T& t, const U& u) { return {}; }
 )cpp",
           ""},
   };

clang-tools-extra/docs/ReleaseNotes.rst

@@ -162,6 +162,10 @@ Changes in existing checks
   <clang-tidy/checks/bugprone/dangling-handle>` check to treat `std::span` as a
   handle class.
 
+- Improved :doc:`bugprone-exception-escape
+  <clang-tidy/checks/bugprone/exception-escape>` by fixing false positives
+  when a consteval function with throw statements.
+
 - Improved :doc:`bugprone-forwarding-reference-overload
   <clang-tidy/checks/bugprone/forwarding-reference-overload>` check by fixing
   a crash when determining if an ``enable_if[_t]`` was found.