Debug info: (Bugfix) Make sure artificial functions like _GLOBAL__I_a

are not associated with any source lines.

Previously, if the Location of a Decl was empty, EmitFunctionStart would
just keep using CurLoc, which would sometimes be correct (e.g., thunks)
but in other cases would just point to a hilariously random location.

This patch fixes this by completely eliminating all uses of CurLoc from
EmitFunctionStart and rather have clients explicitly pass in a
SourceLocation for the function header and the function body.

rdar://problem/14985269

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@205999 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 15b08d476c7a49cbc2af6f27b88be6e853fb35ec..c1cbfde4b5e2c90c379be847f4e05eafdef303e0 100644 (file)
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -1135,6 +1135,7 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
 
   // Begin generating the function.
   StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
+                blockDecl->getLocation(),
                 blockInfo.getBlockExpr()->getBody()->getLocStart());
 
   // Okay.  Undo some of what StartFunction did.
@@ -1306,7 +1307,7 @@ CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
                                           false);
   // Create a scope with an artificial location for the body of this function.
   ArtificialLocation AL(*this, Builder);
-  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation(), SourceLocation());
   AL.Emit();
 
   llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
@@ -1476,7 +1477,7 @@ CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
                                           false, false);
   // Create a scope with an artificial location for the body of this function.
   ArtificialLocation AL(*this, Builder);
-  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation(), SourceLocation());
   AL.Emit();
 
   llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
@@ -1765,7 +1766,7 @@ generateByrefCopyHelper(CodeGenFunction &CGF,
                                           SC_Static,
                                           false, false);
 
-  CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation());
+  CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation(), SourceLocation());
 
   if (byrefInfo.needsCopy()) {
     llvm::Type *byrefPtrType = byrefType.getPointerTo(0);
@@ -1834,7 +1835,7 @@ generateByrefDisposeHelper(CodeGenFunction &CGF,
                                           SourceLocation(), II, R, 0,
                                           SC_Static,
                                           false, false);
-  CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation());
+  CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation(), SourceLocation());
 
   if (byrefInfo.needsDispose()) {
     llvm::Value *V = CGF.GetAddrOfLocalVar(&src);

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 45c78064aac15dbd66c56cd44a40a838ad29ee9b..8e06bbd34b6f1d60df6aec9bc7092b7c5c014244 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -2504,7 +2504,10 @@ llvm::DICompositeType CGDebugInfo::getOrCreateFunctionType(const Decl *D,
 }
 
 /// EmitFunctionStart - Constructs the debug code for entering a function.
-void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
+void CGDebugInfo::EmitFunctionStart(GlobalDecl GD,
+                                    SourceLocation Loc,
+                                    SourceLocation ScopeLoc,
+                                    QualType FnType,
                                     llvm::Function *Fn,
                                     CGBuilderTy &Builder) {
 
@@ -2514,24 +2517,7 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
   FnBeginRegionCount.push_back(LexicalBlockStack.size());
 
   const Decl *D = GD.getDecl();
-
-  // Use the location of the start of the function to determine where
-  // the function definition is located. By default use the location
-  // of the declaration as the location for the subprogram. A function
-  // may lack a declaration in the source code if it is created by code
-  // gen. (examples: _GLOBAL__I_a, __cxx_global_array_dtor, thunk).
   bool HasDecl = (D != 0);
-  SourceLocation Loc;
-  if (HasDecl) {
-    Loc = D->getLocation();
-
-    // If this is a function specialization then use the pattern body
-    // as the location for the function.
-    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
-      if (const FunctionDecl *SpecDecl = FD->getTemplateInstantiationPattern())
-        if (SpecDecl->hasBody(SpecDecl))
-          Loc = SpecDecl->getLocation();
-  }
 
   unsigned Flags = 0;
   llvm::DIFile Unit = getOrCreateFile(Loc);
@@ -2591,9 +2577,14 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
   if (!Name.empty() && Name[0] == '\01')
     Name = Name.substr(1);
 
-  unsigned LineNo = getLineNumber(Loc);
-  if (!HasDecl || D->isImplicit())
+  if (!HasDecl || D->isImplicit()) {
     Flags |= llvm::DIDescriptor::FlagArtificial;
+    // Artificial functions without a location should not silently reuse CurLoc.
+    if (Loc.isInvalid())
+      CurLoc = SourceLocation();
+  }
+  unsigned LineNo = getLineNumber(Loc);
+  unsigned ScopeLine = getLineNumber(ScopeLoc);
 
   // FIXME: The function declaration we're constructing here is mostly reusing
   // declarations from CXXMethodDecl and not constructing new ones for arbitrary
@@ -2604,7 +2595,7 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, QualType FnType,
       DBuilder.createFunction(FDContext, Name, LinkageName, Unit, LineNo,
                               getOrCreateFunctionType(D, FnType, Unit),
                               Fn->hasInternalLinkage(), true /*definition*/,
-                              getLineNumber(CurLoc), Flags,
+                              ScopeLine, Flags,
                               CGM.getLangOpts().Optimize, Fn, TParamsArray,
                               getFunctionDeclaration(D));
   if (HasDecl)

diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index 7f2ddd06367c8bf2c15105d0ddb03040cb23e10f..2fc35d5b87c6fa1ab031756088f49daa0af24e2d 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -220,8 +220,12 @@ public:
 
   /// EmitFunctionStart - Emit a call to llvm.dbg.function.start to indicate
   /// start of a new function.
-  void EmitFunctionStart(GlobalDecl GD, QualType FnType,
-                         llvm::Function *Fn, CGBuilderTy &Builder);
+  /// \param Loc       The location of the function header.
+  /// \param ScopeLoc  The location of the function body.
+  void EmitFunctionStart(GlobalDecl GD,
+                         SourceLocation Loc, SourceLocation ScopeLoc,
+                         QualType FnType, llvm::Function *Fn,
+                         CGBuilderTy &Builder);
 
   /// EmitFunctionEnd - Constructs the debug code for exiting a function.
   void EmitFunctionEnd(CGBuilderTy &Builder);

diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index bc8620d4424de2e31a005e09c66068869c77c44b..558c91be955f96c8b3d82196fc10c3b9adf06614 100644 (file)
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -179,7 +179,7 @@ static llvm::Constant *createAtExitStub(CodeGenModule &CGM, const VarDecl &VD,
 
   CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn,
                     CGM.getTypes().arrangeNullaryFunction(), FunctionArgList(),
-                    SourceLocation());
+                    SourceLocation(), SourceLocation());
 
   llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
  
@@ -412,7 +412,8 @@ void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
 
   StartFunction(GlobalDecl(D), getContext().VoidTy, Fn,
                 getTypes().arrangeNullaryFunction(),
-                FunctionArgList(), D->getInit()->getExprLoc());
+                FunctionArgList(), D->getLocation(),
+                D->getInit()->getExprLoc());
 
   // Use guarded initialization if the global variable is weak. This
   // occurs for, e.g., instantiated static data members and
@@ -433,7 +434,7 @@ CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
                                            llvm::GlobalVariable *Guard) {
   StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                 getTypes().arrangeNullaryFunction(),
-                FunctionArgList(), SourceLocation());
+                FunctionArgList(), SourceLocation(), SourceLocation());
 
   llvm::BasicBlock *ExitBlock = 0;
   if (Guard) {
@@ -479,7 +480,7 @@ void CodeGenFunction::GenerateCXXGlobalDtorsFunc(llvm::Function *Fn,
                                                 &DtorsAndObjects) {
   StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                 getTypes().arrangeNullaryFunction(),
-                FunctionArgList(), SourceLocation());
+                FunctionArgList(), SourceLocation(), SourceLocation());
 
   // Emit the dtors, in reverse order from construction.
   for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) {
@@ -509,7 +510,8 @@ llvm::Function *CodeGenFunction::generateDestroyHelper(
   llvm::Function *fn = 
     CreateGlobalInitOrDestructFunction(CGM, FTy, "__cxx_global_array_dtor");
 
-  StartFunction(VD, getContext().VoidTy, fn, FI, args, SourceLocation());
+  StartFunction(VD, getContext().VoidTy, fn, FI, args,
+                SourceLocation(), SourceLocation());
 
   emitDestroy(addr, type, destroyer, useEHCleanupForArray);
   

diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index f78bb0b3106f1aa9052aec4d7f8e9f5d65480bda..b34c19cb942e094ebee76b8a0daf500fdcab40d6 100644 (file)
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -481,7 +481,8 @@ void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
 
   CurGD = OMD;
 
-  StartFunction(OMD, OMD->getReturnType(), Fn, FI, args, StartLoc);
+  StartFunction(OMD, OMD->getReturnType(), Fn, FI, args,
+                OMD->getLocation(), StartLoc);
 
   // In ARC, certain methods get an extra cleanup.
   if (CGM.getLangOpts().ObjCAutoRefCount &&
@@ -2915,7 +2916,7 @@ CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
                            "__assign_helper_atomic_property_",
                            &CGM.getModule());
   
-  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation(), SourceLocation());
   
   DeclRefExpr DstExpr(&dstDecl, false, DestTy,
                       VK_RValue, SourceLocation());
@@ -2993,7 +2994,7 @@ CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
   llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
                          "__copy_helper_atomic_property_", &CGM.getModule());
   
-  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation(), SourceLocation());
   
   DeclRefExpr SrcExpr(&srcDecl, false, SrcTy,
                       VK_RValue, SourceLocation());

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index cba9e6cd4d3098faca60d0e6b95d9da0090efd01..d50d8b959a880fe6ca7f0481208b2880f0bceb05 100644 (file)
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -1944,7 +1944,9 @@ CodeGenFunction::GenerateCapturedStmtFunction(const CapturedDecl *CD,
   CGM.SetInternalFunctionAttributes(CD, F, FuncInfo);
 
   // Generate the function.
-  StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getBody()->getLocStart());
+  StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args,
+                CD->getLocation(),
+                CD->getBody()->getLocStart());
 
   // Set the context parameter in CapturedStmtInfo.
   llvm::Value *DeclPtr = LocalDeclMap[CD->getContextParam()];

diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index 0ad765ce22b82b7845c661bffe5455408bb32a79..08537d5f25cbd5cf1b6b83601ae895a852148d96 100644 (file)
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -217,7 +217,7 @@ void CodeGenFunction::StartThunk(llvm::Function *Fn, GlobalDecl GD,
 
   // Start defining the function.
   StartFunction(GlobalDecl(), ResultType, Fn, FnInfo, FunctionArgs,
-                SourceLocation());
+                MD->getLocation(), SourceLocation());
 
   // Since we didn't pass a GlobalDecl to StartFunction, do this ourselves.
   CGM.getCXXABI().EmitInstanceFunctionProlog(*this);

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index ffaba958fb313d970e78b0f2d1b4f49bcdfba870..95e4ee498d23caf93fdf2402e54e6e2e65362880 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -503,6 +503,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
                                     llvm::Function *Fn,
                                     const CGFunctionInfo &FnInfo,
                                     const FunctionArgList &Args,
+                                    SourceLocation Loc,
                                     SourceLocation StartLoc) {
   const Decl *D = GD.getDecl();
 
@@ -580,9 +581,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
     QualType FnType =
       getContext().getFunctionType(RetTy, ArgTypes,
                                    FunctionProtoType::ExtProtoInfo());
-
-    DI->setLocation(StartLoc);
-    DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
+    DI->EmitFunctionStart(GD, Loc, StartLoc, FnType, CurFn, Builder);
   }
 
   if (ShouldInstrumentFunction())
@@ -759,8 +758,24 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
   CurEHLocation = BodyRange.getEnd();
 
+  // Use the location of the start of the function to determine where
+  // the function definition is located. By default use the location
+  // of the declaration as the location for the subprogram. A function
+  // may lack a declaration in the source code if it is created by code
+  // gen. (examples: _GLOBAL__I_a, __cxx_global_array_dtor, thunk).
+  SourceLocation Loc;
+  if (FD) {
+    Loc = FD->getLocation();
+
+    // If this is a function specialization then use the pattern body
+    // as the location for the function.
+    if (const FunctionDecl *SpecDecl = FD->getTemplateInstantiationPattern())
+      if (SpecDecl->hasBody(SpecDecl))
+        Loc = SpecDecl->getLocation();
+  }
+
   // Emit the standard function prologue.
-  StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
+  StartFunction(GD, ResTy, Fn, FnInfo, Args, Loc, BodyRange.getBegin());
 
   // Generate the body of the function.
   PGO.assignRegionCounters(GD.getDecl(), CurFn);

diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 5b0653adc69055f80a5dd5b8bd8202be742bfde0..56ad76ae926443bd10b03a0a0dd1ae94554f7ec3 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1140,11 +1140,15 @@ public:
 
   void GenerateCode(GlobalDecl GD, llvm::Function *Fn,
                     const CGFunctionInfo &FnInfo);
+  /// \brief Emit code for the start of a function.
+  /// \param Loc       The location to be associated with the function.
+  /// \param StartLoc  The location of the function body.
   void StartFunction(GlobalDecl GD,
                      QualType RetTy,
                      llvm::Function *Fn,
                      const CGFunctionInfo &FnInfo,
                      const FunctionArgList &Args,
+                     SourceLocation Loc,
                      SourceLocation StartLoc);
 
   void EmitConstructorBody(FunctionArgList &Args);

diff --git a/test/CodeGenCXX/globalinit-loc.cpp b/test/CodeGenCXX/globalinit-loc.cpp
new file mode 100644 (file)
index 0000000..bf3340c
--- /dev/null
+++ b/test/CodeGenCXX/globalinit-loc.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -emit-llvm -g %s -o - | FileCheck %s
+// rdar://problem/14985269.
+//
+// Verify that the global init helper function does not get associated
+// with any source location.
+//
+// CHECK: define internal void @_GLOBAL__I_a
+// CHECK-NOT: !dbg
+// CHECK: "_GLOBAL__I_a", i32 0, {{.*}}, i32 0} ; [ DW_TAG_subprogram ] [line 0] [local] [def]
+# 99 "someheader.h"
+class A {
+public:
+  A();
+  int foo() { return 0; }
+};
+# 5 "main.cpp"
+A a;
+
+int f() {
+  return a.foo();
+}
+