[codeview] Fix symbol names for dynamic initializers and atexit stubs

Summary:
Add a new variant to GlobalDecl for these so that we can detect them
more easily during debug info emission and handle them appropriately.

Reviewers: rsmith, rjmccall, jyu2

Subscribers: aprantl, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60930

llvm-svn: 359148

3 files changed, 70 insertions, 6 deletions

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 95ec4fa690c..d62757ec917 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1880,6 +1880,58 @@ StringRef CGDebugInfo::getVTableName(const CXXRecordDecl *RD) {
   return internString("_vptr$", RD->getNameAsString());
 }
 
+StringRef CGDebugInfo::getDynamicInitializerName(const VarDecl *VD,
+                                                 DynamicInitKind StubKind,
+                                                 llvm::Function *InitFn) {
+  // If we're not emitting codeview, use the mangled name. For Itanium, this is
+  // arbitrary.
+  if (!CGM.getCodeGenOpts().EmitCodeView)
+    return InitFn->getName();
+
+  // Print the normal qualified name for the variable, then break off the last
+  // NNS, and add the appropriate other text. Clang always prints the global
+  // variable name without template arguments, so we can use rsplit("::") and
+  // then recombine the pieces.
+  SmallString<128> QualifiedGV;
+  StringRef Quals;
+  StringRef GVName;
+  {
+    llvm::raw_svector_ostream OS(QualifiedGV);
+    VD->printQualifiedName(OS, getPrintingPolicy());
+    std::tie(Quals, GVName) = OS.str().rsplit("::");
+    if (GVName.empty())
+      std::swap(Quals, GVName);
+  }
+
+  SmallString<128> InitName;
+  llvm::raw_svector_ostream OS(InitName);
+  if (!Quals.empty())
+    OS << Quals << "::";
+
+  switch (StubKind) {
+  case DynamicInitKind::NoStub:
+    llvm_unreachable("not an initializer");
+  case DynamicInitKind::Initializer:
+    OS << "`dynamic initializer for '";
+    break;
+  case DynamicInitKind::AtExit:
+    OS << "`dynamic atexit destructor for '";
+    break;
+  }
+
+  OS << GVName;
+
+  // Add any template specialization args.
+  if (const auto *VTpl = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
+    printTemplateArgumentList(OS, VTpl->getTemplateArgs().asArray(),
+                              getPrintingPolicy());
+  }
+
+  OS << '\'';
+
+  return internString(OS.str());
+}
+
 void CGDebugInfo::CollectVTableInfo(const CXXRecordDecl *RD, llvm::DIFile *Unit,
                                     SmallVectorImpl<llvm::Metadata *> &EltTys,
                                     llvm::DICompositeType *RecordTy) {
@@ -3470,6 +3522,11 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, SourceLocation Loc,
   } else if (const auto *OMD = dyn_cast<ObjCMethodDecl>(D)) {
     Name = getObjCMethodName(OMD);
     Flags |= llvm::DINode::FlagPrototyped;
+  } else if (isa<VarDecl>(D) &&
+             GD.getDynamicInitKind() != DynamicInitKind::NoStub) {
+    // This is a global initializer or atexit destructor for a global variable.
+    Name = getDynamicInitializerName(cast<VarDecl>(D), GD.getDynamicInitKind(),
+                                     Fn);
   } else {
     // Use llvm function name.
     Name = Fn->getName();
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index fd7df089190..054df01d97c 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -41,6 +41,7 @@ class ObjCInterfaceDecl;
 class ObjCIvarDecl;
 class UsingDecl;
 class VarDecl;
+enum class DynamicInitKind : unsigned;
 
 namespace CodeGen {
 class CodeGenModule;
@@ -648,6 +649,12 @@ private:
   /// Get the vtable name for the given class.
   StringRef getVTableName(const CXXRecordDecl *Decl);
 
+  /// Get the name to use in the debug info for a dynamic initializer or atexit
+  /// stub function.
+  StringRef getDynamicInitializerName(const VarDecl *VD,
+                                      DynamicInitKind StubKind,
+                                      llvm::Function *InitFn);
+
   /// Get line number for the location. If location is invalid
   /// then use current location.
   unsigned getLineNumber(SourceLocation Loc);
diff --git a/clang/lib/CodeGen/CGDeclCXX.cpp b/clang/lib/CodeGen/CGDeclCXX.cpp
index cd3301bd6ca..15ab1638c67 100644
--- a/clang/lib/CodeGen/CGDeclCXX.cpp
+++ b/clang/lib/CodeGen/CGDeclCXX.cpp
@@ -226,13 +226,13 @@ llvm::Function *CodeGenFunction::createAtExitStub(const VarDecl &VD,
   }
 
   const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
-  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(ty, FnName.str(),
-                                                              FI,
-                                                              VD.getLocation());
+  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
+      ty, FnName.str(), FI, VD.getLocation());
 
   CodeGenFunction CGF(CGM);
 
-  CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn, FI, FunctionArgList());
+  CGF.StartFunction(GlobalDecl(&VD, DynamicInitKind::AtExit),
+                    CGM.getContext().VoidTy, fn, FI, FunctionArgList());
 
   llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
 
@@ -603,8 +603,8 @@ void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
 
   CurEHLocation = D->getBeginLoc();
 
-  StartFunction(GlobalDecl(D), getContext().VoidTy, Fn,
-                getTypes().arrangeNullaryFunction(),
+  StartFunction(GlobalDecl(D, DynamicInitKind::Initializer),
+                getContext().VoidTy, Fn, getTypes().arrangeNullaryFunction(),
                 FunctionArgList(), D->getLocation(),
                 D->getInit()->getExprLoc());