[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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@359148 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 120 insertions, 15 deletions

diff --git a/include/clang/AST/GlobalDecl.h b/include/clang/AST/GlobalDecl.h
index b40099f509..86fd0f6aa9 100644
--- a/include/clang/AST/GlobalDecl.h
+++ b/include/clang/AST/GlobalDecl.h
@@ -27,6 +27,12 @@
 
 namespace clang {
 
+enum class DynamicInitKind : unsigned {
+  NoStub = 0,
+  Initializer,
+  AtExit,
+};
+
 /// GlobalDecl - represents a global declaration. This can either be a
 /// CXXConstructorDecl and the constructor type (Base, Complete).
 /// a CXXDestructorDecl and the destructor type (Base, Complete) or
@@ -55,6 +61,8 @@ public:
   GlobalDecl(const OMPDeclareReductionDecl *D) { Init(D); }
   GlobalDecl(const CXXConstructorDecl *D, CXXCtorType Type) : Value(D, Type) {}
   GlobalDecl(const CXXDestructorDecl *D, CXXDtorType Type) : Value(D, Type) {}
+  GlobalDecl(const VarDecl *D, DynamicInitKind StubKind)
+      : Value(D, unsigned(StubKind)) {}
 
   GlobalDecl getCanonicalDecl() const {
     GlobalDecl CanonGD;
@@ -77,6 +85,13 @@ public:
     return static_cast<CXXDtorType>(Value.getInt());
   }
 
+  DynamicInitKind getDynamicInitKind() const {
+    assert(isa<VarDecl>(getDecl()) &&
+           cast<VarDecl>(getDecl())->hasGlobalStorage() &&
+           "Decl is not a global variable!");
+    return static_cast<DynamicInitKind>(Value.getInt());
+  }
+
   unsigned getMultiVersionIndex() const {
     assert(isa<FunctionDecl>(getDecl()) &&
            !isa<CXXConstructorDecl>(getDecl()) &&
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 95ec4fa690..d62757ec91 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/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/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index fd7df08919..054df01d97 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/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/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index cd3301bd6c..15ab1638c6 100644
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/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());
 
diff --git a/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp b/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
index 0ede3c6e48..e3df9ca9ae 100644
--- a/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
+++ b/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
@@ -2,11 +2,14 @@
 // RUN:     | FileCheck %s --check-prefix=CHECK-NOKEXT
 // RUN: %clang_cc1 %s -debug-info-kind=limited -triple %itanium_abi_triple -fno-use-cxa-atexit -fapple-kext -S -disable-O0-optnone -emit-llvm -o - \
 // RUN:     | FileCheck %s --check-prefix=CHECK-KEXT
+// RUN: %clang_cc1 %s -gcodeview -debug-info-kind=limited -triple x86_64-windows-msvc -fno-use-cxa-atexit -S -disable-O0-optnone  -emit-llvm -o - \
+// RUN:     | FileCheck %s --check-prefix=CHECK-MSVC
 
 class A {
- public:
-  A() {}
-  virtual ~A() {}
+public:
+  A();
+  A(int x);
+  virtual ~A();
 };
 
 A glob;
@@ -16,12 +19,35 @@ void foo() {
   static A stat;
 }
 
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init",{{.*}} line: 12,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor_glob",{{.*}} line: 12,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init.1",{{.*}} line: 13,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} line: 13,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor_array",{{.*}} line: 13,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
-// CHECK-NOKEXT: !DISubprogram(name: "__dtor__ZZ3foovE4stat",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+template <typename T>
+struct FooTpl {
+  template <typename U>
+  static A sdm_tpl;
+};
+template <typename T>
+template <typename U>
+A FooTpl<T>::sdm_tpl(sizeof(U) + sizeof(T));
+template A FooTpl<int>::sdm_tpl<int>;
+
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init",{{.*}} line: 15,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor_glob",{{.*}} line: 15,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_var_init.1",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor_array",{{.*}} line: 16,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-NOKEXT: !DISubprogram(name: "__dtor__ZZ3foovE4stat",{{.*}} line: 19,{{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
 // CHECK-NOKEXT: !DISubprogram({{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
 
 // CHECK-KEXT: !DISubprogram({{.*}} DISPFlagLocalToUnit | DISPFlagDefinition
+
+// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'glob'",{{.*}} line: 15,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'glob'",{{.*}} line: 15,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic initializer for 'array'",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "__cxx_global_array_dtor",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'array'",{{.*}} line: 16,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "`dynamic atexit destructor for 'stat'",{{.*}} line: 19,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+
+// MSVC does weird stuff when templates are involved, so we don't match exactly,
+// but these names are reasonable.
+// FIXME: These should not be marked DISPFlagLocalToUnit.
+// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic initializer for 'sdm_tpl<int>'",{{.*}} line: 29,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition
+// CHECK-MSVC: !DISubprogram(name: "FooTpl<int>::`dynamic atexit destructor for 'sdm_tpl<int>'",{{.*}} line: 29,{{.*}}: DISPFlagLocalToUnit | DISPFlagDefinition