[DebugInfo] Added support to Clang FE for generating debug info for preprocessor macros.

Added "-fdebug-macro" flag (and "-fno-debug-macro" flag) to enable (and to disable) emitting macro debug info.
Added CC1 "-debug-info-macro" flag that enables emitting macro debug info.

Differential Revision: https://reviews.llvm.org/D16135

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@294637 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 377 insertions, 0 deletions

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 7eb0af2d37..b48714f69b 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -2419,6 +2419,21 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
                                         FullName);
 }
 
+llvm::DIMacro *CGDebugInfo::CreateMacro(llvm::DIMacroFile *Parent,
+                                        unsigned MType, SourceLocation LineLoc,
+                                        StringRef Name, StringRef Value) {
+  unsigned Line = LineLoc.isInvalid() ? 0 : getLineNumber(LineLoc);
+  return DBuilder.createMacro(Parent, Line, MType, Name, Value);
+}
+
+llvm::DIMacroFile *CGDebugInfo::CreateTempMacroFile(llvm::DIMacroFile *Parent,
+                                                    SourceLocation LineLoc,
+                                                    SourceLocation FileLoc) {
+  llvm::DIFile *FName = getOrCreateFile(FileLoc);
+  unsigned Line = LineLoc.isInvalid() ? 0 : getLineNumber(LineLoc);
+  return DBuilder.createTempMacroFile(Parent, Line, FName);
+}
+
 static QualType UnwrapTypeForDebugInfo(QualType T, const ASTContext &C) {
   Qualifiers Quals;
   do {
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index ea451d0548..050665e92e 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -413,6 +413,16 @@ public:
 
   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
 
+  /// Create debug info for a macro defined by a #define directive or a macro
+  /// undefined by a #undef directive.
+  llvm::DIMacro *CreateMacro(llvm::DIMacroFile *Parent, unsigned MType,
+                             SourceLocation LineLoc, StringRef Name,
+                             StringRef Value);
+
+  /// Create debug info for a file referenced by an #include directive.
+  llvm::DIMacroFile *CreateTempMacroFile(llvm::DIMacroFile *Parent,
+                                         SourceLocation LineLoc,
+                                         SourceLocation FileLoc);
 private:
   /// Emit call to llvm.dbg.declare for a variable declaration.
   void EmitDeclare(const VarDecl *decl, llvm::Value *AI,
diff --git a/lib/CodeGen/CMakeLists.txt b/lib/CodeGen/CMakeLists.txt
index 1e9a43af52..f34456e9fa 100644
--- a/lib/CodeGen/CMakeLists.txt
+++ b/lib/CodeGen/CMakeLists.txt
@@ -77,6 +77,7 @@ add_clang_library(clangCodeGen
   CodeGenTypes.cpp
   CoverageMappingGen.cpp
   ItaniumCXXABI.cpp
+  MacroPPCallbacks.cpp
   MicrosoftCXXABI.cpp
   ModuleBuilder.cpp
   ObjectFilePCHContainerOperations.cpp
diff --git a/lib/CodeGen/CodeGenAction.cpp b/lib/CodeGen/CodeGenAction.cpp
index 3828c5e170..89a7c7c727 100644
--- a/lib/CodeGen/CodeGenAction.cpp
+++ b/lib/CodeGen/CodeGenAction.cpp
@@ -10,6 +10,7 @@
 #include "clang/CodeGen/CodeGenAction.h"
 #include "CodeGenModule.h"
 #include "CoverageMappingGen.h"
+#include "MacroPPCallbacks.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclCXX.h"
@@ -97,6 +98,8 @@ namespace clang {
       return std::unique_ptr<llvm::Module>(Gen->ReleaseModule());
     }
 
+    CodeGenerator *getCodeGenerator() { return Gen.get(); }
+
     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
       Gen->HandleCXXStaticMemberVarInstantiation(VD);
     }
@@ -830,6 +833,17 @@ CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
       CI.getLangOpts(), CI.getFrontendOpts().ShowTimers, InFile,
       std::move(LinkModules), std::move(OS), *VMContext, CoverageInfo));
   BEConsumer = Result.get();
+
+  // Enable generating macro debug info only when debug info is not disabled and
+  // also macro debug info is enabled.
+  if (CI.getCodeGenOpts().getDebugInfo() != codegenoptions::NoDebugInfo &&
+      CI.getCodeGenOpts().MacroDebugInfo) {
+    std::unique_ptr<PPCallbacks> Callbacks =
+        llvm::make_unique<MacroPPCallbacks>(BEConsumer->getCodeGenerator(),
+                                            CI.getPreprocessor());
+    CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
+  }
+
   return std::move(Result);
 }
 
diff --git a/lib/CodeGen/MacroPPCallbacks.cpp b/lib/CodeGen/MacroPPCallbacks.cpp
new file mode 100644
index 0000000000..71eb55ca2f
--- /dev/null
+++ b/lib/CodeGen/MacroPPCallbacks.cpp
@@ -0,0 +1,211 @@
+//===--- MacroPPCallbacks.cpp ---------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file contains implementation for the macro preprocessors callbacks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MacroPPCallbacks.h"
+#include "CGDebugInfo.h"
+#include "clang/CodeGen/ModuleBuilder.h"
+#include "clang/Parse/Parser.h"
+
+using namespace clang;
+
+void MacroPPCallbacks::writeMacroDefinition(const IdentifierInfo &II,
+                                            const MacroInfo &MI,
+                                            Preprocessor &PP, raw_ostream &Name,
+                                            raw_ostream &Value) {
+  Name << II.getName();
+
+  if (MI.isFunctionLike()) {
+    Name << '(';
+    if (!MI.arg_empty()) {
+      MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
+      for (; AI + 1 != E; ++AI) {
+        Name << (*AI)->getName();
+        Name << ',';
+      }
+
+      // Last argument.
+      if ((*AI)->getName() == "__VA_ARGS__")
+        Name << "...";
+      else
+        Name << (*AI)->getName();
+    }
+
+    if (MI.isGNUVarargs())
+      // #define foo(x...)
+      Name << "...";
+
+    Name << ')';
+  }
+
+  SmallString<128> SpellingBuffer;
+  bool First = true;
+  for (const auto &T : MI.tokens()) {
+    if (!First && T.hasLeadingSpace())
+      Value << ' ';
+
+    Value << PP.getSpelling(T, SpellingBuffer);
+    First = false;
+  }
+}
+
+MacroPPCallbacks::MacroPPCallbacks(CodeGenerator *Gen, Preprocessor &PP)
+    : Gen(Gen), PP(PP), Status(NoScope) {}
+
+/*
+  This is the expected flow of enter/exit compiler and user files:
+  - Main File Enter
+    - <built-in> file enter
+      {Compiler macro definitions} - (Line=0, no scope)
+      - (Optional) <command line> file enter
+      {Command line macro definitions} - (Line=0, no scope)
+      - (Optional) <command line> file exit
+      {Command line file includes} - (Line=0, Main file scope)
+        {macro definitions and file includes} - (Line!=0, Parent scope)
+    - <built-in> file exit
+    {User code macro definitions and file includes} - (Line!=0, Parent scope)
+*/
+
+llvm::DIMacroFile *MacroPPCallbacks::getCurrentScope() {
+  if (Status == MainFileScope || Status == CommandLineIncludeScope)
+    return Scopes.back();
+  return nullptr;
+}
+
+SourceLocation MacroPPCallbacks::getCorrectLocation(SourceLocation Loc) {
+  if (Status == MainFileScope || EnteredCommandLineIncludeFiles)
+    return Loc;
+
+  // While parsing skipped files, location of macros is invalid.
+  // Invalid location represents line zero.
+  return SourceLocation();
+}
+
+static bool isBuiltinFile(SourceManager &SM, SourceLocation Loc) {
+  StringRef Filename(SM.getPresumedLoc(Loc).getFilename());
+  return Filename.equals("<built-in>");
+}
+
+static bool isCommandLineFile(SourceManager &SM, SourceLocation Loc) {
+  StringRef Filename(SM.getPresumedLoc(Loc).getFilename());
+  return Filename.equals("<command line>");
+}
+
+void MacroPPCallbacks::updateStatusToNextScope() {
+  switch (Status) {
+  case NoScope:
+    Status = InitializedScope;
+    break;
+  case InitializedScope:
+    Status = BuiltinScope;
+    break;
+  case BuiltinScope:
+    Status = CommandLineIncludeScope;
+    break;
+  case CommandLineIncludeScope:
+    Status = MainFileScope;
+    break;
+  case MainFileScope:
+    llvm_unreachable("There is no next scope, already in the final scope");
+  }
+}
+
+void MacroPPCallbacks::FileEntered(SourceLocation Loc) {
+  SourceLocation LineLoc = getCorrectLocation(LastHashLoc);
+  switch (Status) {
+  default:
+    llvm_unreachable("Do not expect to enter a file from current scope");
+  case NoScope:
+    updateStatusToNextScope();
+    break;
+  case InitializedScope:
+    updateStatusToNextScope();
+    return;
+  case BuiltinScope:
+    if (isCommandLineFile(PP.getSourceManager(), Loc))
+      return;
+    updateStatusToNextScope();
+    LLVM_FALLTHROUGH;
+  case CommandLineIncludeScope:
+    EnteredCommandLineIncludeFiles++;
+    break;
+  case MainFileScope:
+    break;
+  }
+
+  Scopes.push_back(Gen->getCGDebugInfo()->CreateTempMacroFile(getCurrentScope(),
+                                                              LineLoc, Loc));
+}
+
+void MacroPPCallbacks::FileExited(SourceLocation Loc) {
+  switch (Status) {
+  default:
+    llvm_unreachable("Do not expect to exit a file from current scope");
+  case BuiltinScope:
+    if (!isBuiltinFile(PP.getSourceManager(), Loc))
+      // Skip next scope and change status to MainFileScope.
+      Status = MainFileScope;
+    return;
+  case CommandLineIncludeScope:
+    if (!EnteredCommandLineIncludeFiles) {
+      updateStatusToNextScope();
+      return;
+    }
+    EnteredCommandLineIncludeFiles--;
+    break;
+  case MainFileScope:
+    break;
+  }
+
+  Scopes.pop_back();
+}
+
+void MacroPPCallbacks::FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                                   SrcMgr::CharacteristicKind FileType,
+                                   FileID PrevFID) {
+  // Only care about enter file or exit file changes.
+  if (Reason == EnterFile)
+    FileEntered(Loc);
+  else if (Reason == ExitFile)
+    FileExited(Loc);
+}
+
+void MacroPPCallbacks::InclusionDirective(
+    SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
+    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    StringRef SearchPath, StringRef RelativePath, const Module *Imported) {
+
+  // Record the line location of the current included file.
+  LastHashLoc = HashLoc;
+}
+
+void MacroPPCallbacks::MacroDefined(const Token &MacroNameTok,
+                                    const MacroDirective *MD) {
+  IdentifierInfo *Id = MacroNameTok.getIdentifierInfo();
+  SourceLocation location = getCorrectLocation(MacroNameTok.getLocation());
+  std::string NameBuffer, ValueBuffer;
+  llvm::raw_string_ostream Name(NameBuffer);
+  llvm::raw_string_ostream Value(ValueBuffer);
+  writeMacroDefinition(*Id, *MD->getMacroInfo(), PP, Name, Value);
+  Gen->getCGDebugInfo()->CreateMacro(getCurrentScope(),
+                                     llvm::dwarf::DW_MACINFO_define, location,
+                                     Name.str(), Value.str());
+}
+
+void MacroPPCallbacks::MacroUndefined(const Token &MacroNameTok,
+                                      const MacroDefinition &MD) {
+  IdentifierInfo *Id = MacroNameTok.getIdentifierInfo();
+  SourceLocation location = getCorrectLocation(MacroNameTok.getLocation());
+  Gen->getCGDebugInfo()->CreateMacro(getCurrentScope(),
+                                     llvm::dwarf::DW_MACINFO_undef, location,
+                                     Id->getName(), "");
+}
diff --git a/lib/CodeGen/MacroPPCallbacks.h b/lib/CodeGen/MacroPPCallbacks.h
new file mode 100644
index 0000000000..f02801dc32
--- /dev/null
+++ b/lib/CodeGen/MacroPPCallbacks.h
@@ -0,0 +1,118 @@
+//===--- MacroPPCallbacks.h -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines implementation for the macro preprocessors callbacks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/PPCallbacks.h"
+
+namespace llvm {
+class DIMacroFile;
+class DIMacroNode;
+}
+namespace clang {
+class Preprocessor;
+class MacroInfo;
+class CodeGenerator;
+
+class MacroPPCallbacks : public PPCallbacks {
+  /// A pointer to code generator, where debug info generator can be found.
+  CodeGenerator *Gen;
+
+  /// Preprocessor.
+  Preprocessor &PP;
+
+  /// Location of recent included file, used for line number.
+  SourceLocation LastHashLoc;
+
+  /// Counts current number of command line included files, which were entered
+  /// and were not exited yet.
+  int EnteredCommandLineIncludeFiles = 0;
+
+  enum FileScopeStatus {
+    NoScope = 0,              // Scope is not initialized yet.
+    InitializedScope,         // Main file scope is initialized but not set yet.
+    BuiltinScope,             // <built-in> and <command line> file scopes.
+    CommandLineIncludeScope,  // Included file, from <command line> file, scope.
+    MainFileScope             // Main file scope.
+  };
+  FileScopeStatus Status;
+
+  /// Parent contains all entered files that were not exited yet according to
+  /// the inclusion order.
+  llvm::SmallVector<llvm::DIMacroFile *, 4> Scopes;
+
+  /// Get current DIMacroFile scope.
+  /// \return current DIMacroFile scope or nullptr if there is no such scope.
+  llvm::DIMacroFile *getCurrentScope();
+
+  /// Get current line location or invalid location.
+  /// \param Loc current line location.
+  /// \return current line location \p `Loc`, or invalid location if it's in a
+  ///         skipped file scope.
+  SourceLocation getCorrectLocation(SourceLocation Loc);
+
+  /// Use the passed preprocessor to write the macro name and value from the
+  /// given macro info and identifier info into the given \p `Name` and \p
+  /// `Value` output streams.
+  ///
+  /// \param II Identifier info, used to get the Macro name.
+  /// \param MI Macro info, used to get the Macro argumets and values.
+  /// \param PP Preprocessor.
+  /// \param [out] Name Place holder for returned macro name and arguments.
+  /// \param [out] Value Place holder for returned macro value.
+  static void writeMacroDefinition(const IdentifierInfo &II,
+                                   const MacroInfo &MI, Preprocessor &PP,
+                                   raw_ostream &Name, raw_ostream &Value);
+
+  /// Update current file scope status to next file scope.
+  void updateStatusToNextScope();
+
+  /// Handle the case when entering a file.
+  ///
+  /// \param Loc Indicates the new location.
+  /// \Return true if file scope status should be updated.
+  void FileEntered(SourceLocation Loc);
+
+  /// Handle the case when exiting a file.
+  ///
+  /// \Return true if file scope status should be updated.
+  void FileExited(SourceLocation Loc);
+
+public:
+  MacroPPCallbacks(CodeGenerator *Gen, Preprocessor &PP);
+
+  /// Callback invoked whenever a source file is entered or exited.
+  ///
+  /// \param Loc Indicates the new location.
+  /// \param PrevFID the file that was exited if \p Reason is ExitFile.
+  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                   SrcMgr::CharacteristicKind FileType,
+                   FileID PrevFID = FileID()) override;
+
+  /// Callback invoked whenever a directive (#xxx) is processed.
+  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
+                          StringRef FileName, bool IsAngled,
+                          CharSourceRange FilenameRange, const FileEntry *File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported) override;
+
+  /// Hook called whenever a macro definition is seen.
+  void MacroDefined(const Token &MacroNameTok,
+                    const MacroDirective *MD) override;
+
+  /// Hook called whenever a macro \#undef is seen.
+  ///
+  /// MD is released immediately following this callback.
+  void MacroUndefined(const Token &MacroNameTok,
+                      const MacroDefinition &MD) override;
+};
+
+} // end namespace clang
diff --git a/lib/CodeGen/ModuleBuilder.cpp b/lib/CodeGen/ModuleBuilder.cpp
index f925c25491..89090c8b6a 100644
--- a/lib/CodeGen/ModuleBuilder.cpp
+++ b/lib/CodeGen/ModuleBuilder.cpp
@@ -92,6 +92,10 @@ namespace {
       return M.get();
     }
 
+    CGDebugInfo *getCGDebugInfo() {
+      return Builder->getModuleDebugInfo();
+    }
+
     llvm::Module *ReleaseModule() {
       return M.release();
     }
@@ -299,6 +303,10 @@ llvm::Module *CodeGenerator::ReleaseModule() {
   return static_cast<CodeGeneratorImpl*>(this)->ReleaseModule();
 }
 
+CGDebugInfo *CodeGenerator::getCGDebugInfo() {
+  return static_cast<CodeGeneratorImpl*>(this)->getCGDebugInfo();
+}
+
 const Decl *CodeGenerator::GetDeclForMangledName(llvm::StringRef name) {
   return static_cast<CodeGeneratorImpl*>(this)->GetDeclForMangledName(name);
 }