[CodeGen] Add to emitted DebugLoc information about coverage when it's required

[calixte]

Summary

Some lines have a hit counter where they should not have one.
Cleanup stuff is located to the last line of the body which is most of the time a '}'.
And Exception stuff is added at the beginning of a function and at the end (represented by '{' and '}').
So in such cases, the DebugLoc used in GCOVProfiling.cpp must be marked as not covered.
This patch is a followup of https://reviews.llvm.org/D49915.
Tests in projects/compiler_rt are fixed by: https://reviews.llvm.org/D49917

[dblaikie]

Test coverage?

[calixte]

• Use ImplicitCode instead of Covered
• Set Artificial location as ImplicitCode to avoid coverage on landing pads

[calixte]

• Add some ImplicitCode when there is some stuff at the end of a function
• Fix the tests

[calixte]

• only put an ImplicitCode for EmitLandingPad
• fix tests (were broken with clanf-format-diff)

[MaskRay]

@calixte This was reverted and never relanded. Is D49915 (DILocation::ImplicitCode) still needed?

lib/CodeGen/CGDebugInfo.h

public:
   llvm::MDNode *getInlinedAt() const { return CurInlinedAt; }
 
   // Converts a SourceLocation to a DebugLoc
   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Loc);
 
   /// Emit metadata to indicate a change in line/column information in
   /// the source file. If the location is invalid, the previous
   /// location will be reused.
-  void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc);
+  /// \param Covered   True if the Loc must have coverage information 
+  void EmitLocation(CGBuilderTy &Builder, SourceLocation Loc, bool Covered = true);
 
   /// Emit a call to llvm.dbg.function.start to indicate
   /// start of a new function.
   /// \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, bool CurFnIsThunk,
StringRef internString(StringRef A, StringRef B = StringRef()) {
     return StringRef(Data, A.size() + B.size());
   }
 };
 
 /// A scoped helper to set the current debug location to the specified
 /// location or preferred location of the specified Expr.
 class ApplyDebugLocation {
 private:
-  void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false);
+  void init(SourceLocation TemporaryLocation, bool DefaultToEmpty = false, bool Covered = true);
   ApplyDebugLocation(CodeGenFunction &CGF, bool DefaultToEmpty,
                      SourceLocation TemporaryLocation);
 
   llvm::DebugLoc OriginalLocation;
   CodeGenFunction *CGF;
 
 public:
   /// Set the location to the (valid) TemporaryLocation.
-  ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation);
+  ApplyDebugLocation(CodeGenFunction &CGF, SourceLocation TemporaryLocation, bool Covered = true);
   ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
   ApplyDebugLocation(ApplyDebugLocation &&Other) : CGF(Other.CGF) {
     Other.CGF = nullptr;
   }
 
   ~ApplyDebugLocation();
 

lib/CodeGen/CGDebugInfo.cpp

 }
 
 CGDebugInfo::~CGDebugInfo() {
   assert(LexicalBlockStack.empty() &&
          "Region stack mismatch, stack not empty!");
 }
 
 ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF,
-                                       SourceLocation TemporaryLocation)
+                                       SourceLocation TemporaryLocation,
+                                       bool Covered)
     : CGF(&CGF) {
-  init(TemporaryLocation);
+  init(TemporaryLocation, false /* DefaultToEmpty */, Covered);
 }
 
 ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF,
                                        bool DefaultToEmpty,
                                        SourceLocation TemporaryLocation)
     : CGF(&CGF) {
   init(TemporaryLocation, DefaultToEmpty);
 }
 
 void ApplyDebugLocation::init(SourceLocation TemporaryLocation,
-                              bool DefaultToEmpty) {
+                              bool DefaultToEmpty,
+                              bool Covered) {
   auto *DI = CGF->getDebugInfo();
   if (!DI) {
     CGF = nullptr;
     return;
   }
 
   OriginalLocation = CGF->Builder.getCurrentDebugLocation();
 
   if (OriginalLocation && !DI->CGM.getExpressionLocationsEnabled())
     return;
 
   if (TemporaryLocation.isValid()) {
-    DI->EmitLocation(CGF->Builder, TemporaryLocation);
+    DI->EmitLocation(CGF->Builder, TemporaryLocation, Covered);
     return;
   }
 
   if (DefaultToEmpty) {
     CGF->Builder.SetCurrentDebugLocation(llvm::DebugLoc());
     return;
   }
 

 }
 
 void CGDebugInfo::EmitInlineFunctionEnd(CGBuilderTy &Builder) {
   assert(CurInlinedAt && "unbalanced inline scope stack");
   EmitFunctionEnd(Builder, nullptr);
   setInlinedAt(llvm::DebugLoc(CurInlinedAt).getInlinedAt());
 }
 
-void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc) {
+void CGDebugInfo::EmitLocation(CGBuilderTy &Builder, SourceLocation Loc, bool Covered) {
   // Update our current location
   setLocation(Loc);
 
   if (CurLoc.isInvalid() || CurLoc.isMacroID())
     return;
 
   llvm::MDNode *Scope = LexicalBlockStack.back();
   Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(
-      getLineNumber(CurLoc), getColumnNumber(CurLoc), Scope, CurInlinedAt));
+      getLineNumber(CurLoc), getColumnNumber(CurLoc), Scope, CurInlinedAt, Covered));
 }
 
 void CGDebugInfo::CreateLexicalBlock(SourceLocation Loc) {
   llvm::MDNode *Back = nullptr;
   if (!LexicalBlockStack.empty())
     Back = LexicalBlockStack.back().get();
   LexicalBlockStack.emplace_back(DBuilder.createLexicalBlock(
       cast<llvm::DIScope>(Back), getOrCreateFile(CurLoc), getLineNumber(CurLoc),
void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder,
   CreateLexicalBlock(Loc);
 }
 
 void CGDebugInfo::EmitLexicalBlockEnd(CGBuilderTy &Builder,
                                       SourceLocation Loc) {
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
 
   // Provide an entry in the line table for the end of the block.
-  EmitLocation(Builder, Loc);
+  EmitLocation(Builder, Loc, false /* Covered */);
 
   if (DebugKind <= codegenoptions::DebugLineTablesOnly)
     return;
 
   LexicalBlockStack.pop_back();
 }
 
 void CGDebugInfo::EmitFunctionEnd(CGBuilderTy &Builder, llvm::Function *Fn) {
   assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
   unsigned RCount = FnBeginRegionCount.back();
   assert(RCount <= LexicalBlockStack.size() && "Region stack mismatch");
 
   // Pop all regions for this function.
   while (LexicalBlockStack.size() != RCount) {
     // Provide an entry in the line table for the end of the block.
-    EmitLocation(Builder, CurLoc);
+    EmitLocation(Builder, CurLoc, false /* Covered */);
     LexicalBlockStack.pop_back();
   }
   FnBeginRegionCount.pop_back();
 
   if (Fn && Fn->getSubprogram())
     DBuilder.finalizeSubprogram(Fn->getSubprogram());
 }
 

lib/CodeGen/CodeGenFunction.h

public:
     /// cleanups.
     ~LexicalScope() {
       if (CGDebugInfo *DI = CGF.getDebugInfo())
         DI->EmitLexicalBlockEnd(CGF.Builder, Range.getEnd());
 
       // If we should perform a cleanup, force them now.  Note that
       // this ends the cleanup scope before rescoping any labels.
       if (PerformCleanup) {
-        ApplyDebugLocation DL(CGF, Range.getEnd());
+        ApplyDebugLocation DL(CGF, Range.getEnd(), false /* Covered */);
         ForceCleanup();
       }
     }
 
     /// Force the emission of cleanups now, instead of waiting
     /// until this object is destroyed.
     void ForceCleanup() {
       CGF.CurLexicalScope = ParentScope;

lib/CodeGen/CodeGenFunction.cpp

for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
     else
       Ty = VD->getType();
 
     if (Ty->isVariablyModifiedType())
       EmitVariablyModifiedType(Ty);
   }
   // Emit a location at the end of the prologue.
   if (CGDebugInfo *DI = getDebugInfo())
-    DI->EmitLocation(Builder, StartLoc);
+    DI->EmitLocation(Builder, StartLoc, false /* Covered */);
 
   // TODO: Do we need to handle this in two places like we do with
   // target-features/target-cpu?
   if (CurFuncDecl)
     if (const auto *VecWidth = CurFuncDecl->getAttr<MinVectorWidthAttr>())
       LargestVectorWidth = VecWidth->getVectorWidth();
 }