pp-trace/PPCallbacksTracker.cpp - clang-tools-extra - Git at Google

 //===--- PPCallbacksTracker.cpp - Preprocessor tracker -*--*-------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===--------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Implementations for preprocessor tracking.
 ///
 /// See the header for details.
 ///
 //===--------------------------------------------------------------------===//

 #include "PPCallbacksTracker.h"
 #include "clang/Lex/MacroArgs.h"
 #include "llvm/Support/raw_ostream.h"
 #include <stdarg.h>
 #include <stdio.h>

 // Utility functions.

 // Get a "file:line:column" source location string.
 static std::string getSourceLocationString(clang::Preprocessor &PP,
                                            clang::SourceLocation Loc) {
   if (Loc.isInvalid())
     return std::string("(none)");

   if (Loc.isFileID()) {
     clang::PresumedLoc PLoc = PP.getSourceManager().getPresumedLoc(Loc);

     if (PLoc.isInvalid()) {
       return std::string("(invalid)");
     }

     std::string Str;
     llvm::raw_string_ostream SS(Str);

     // The macro expansion and spelling pos is identical for file locs.
     SS << "\"" << PLoc.getFilename() << ':' << PLoc.getLine() << ':'
        << PLoc.getColumn() << "\"";

     std::string Result = SS.str();

     // YAML treats backslash as escape, so use forward slashes.
     std::replace(Result.begin(), Result.end(), '\\', '/');

     return Result;
   }

   return std::string("(nonfile)");
 }

 // Enum string tables.

 // FileChangeReason strings.
 static const char *FileChangeReasonStrings[] = {
   "EnterFile", "ExitFile", "SystemHeaderPragma", "RenameFile"
 };

 // CharacteristicKind strings.
 static const char *CharacteristicKindStrings[] = { "C_User", "C_System",
                                                    "C_ExternCSystem" };

 // MacroDirective::Kind strings.
 static const char *MacroDirectiveKindStrings[] = { "MD_Define", "MD_Undefine",
                                                    "MD_Visibility" };

 // PragmaIntroducerKind strings.
 static const char *PragmaIntroducerKindStrings[] = { "PIK_HashPragma",
                                                      "PIK__Pragma",
                                                      "PIK___pragma" };

 // PragmaMessageKind strings.
 static const char *PragmaMessageKindStrings[] = { "PMK_Message", "PMK_Warning",
                                                   "PMK_Error" };

 // ConditionValueKind strings.
 const char *
 ConditionValueKindStrings[] = {
   "CVK_NotEvaluated", "CVK_False", "CVK_True"
 };

 // Mapping strings.
 static const char *MappingStrings[] = { "0",          "MAP_IGNORE",
                                         "MAP_REMARK", "MAP_WARNING",
                                         "MAP_ERROR",  "MAP_FATAL" };

 // PPCallbacksTracker functions.

 PPCallbacksTracker::PPCallbacksTracker(llvm::SmallSet<std::string, 4> &Ignore,
                                        std::vector<CallbackCall> &CallbackCalls,
                                        clang::Preprocessor &PP)
     : CallbackCalls(CallbackCalls), Ignore(Ignore), PP(PP) {}

 PPCallbacksTracker::~PPCallbacksTracker() {}

 // Callback functions.

 // Callback invoked whenever a source file is entered or exited.
 void PPCallbacksTracker::FileChanged(
     clang::SourceLocation Loc, clang::PPCallbacks::FileChangeReason Reason,
     clang::SrcMgr::CharacteristicKind FileType, clang::FileID PrevFID) {
   beginCallback("FileChanged");
   appendArgument("Loc", Loc);
   appendArgument("Reason", Reason, FileChangeReasonStrings);
   appendArgument("FileType", FileType, CharacteristicKindStrings);
   appendArgument("PrevFID", PrevFID);
 }

 // Callback invoked whenever a source file is skipped as the result
 // of header guard optimization.
 void
 PPCallbacksTracker::FileSkipped(const clang::FileEntry &ParentFile,
                                 const clang::Token &FilenameTok,
                                 clang::SrcMgr::CharacteristicKind FileType) {
   beginCallback("FileSkipped");
   appendArgument("ParentFile", &ParentFile);
   appendArgument("FilenameTok", FilenameTok);
   appendArgument("FileType", FileType, CharacteristicKindStrings);
 }

 // Callback invoked whenever an inclusion directive results in a
 // file-not-found error.
 bool
 PPCallbacksTracker::FileNotFound(llvm::StringRef FileName,
                                  llvm::SmallVectorImpl<char> &RecoveryPath) {
   beginCallback("FileNotFound");
   appendFilePathArgument("FileName", FileName);
   return false;
 }

 // Callback invoked whenever an inclusion directive of
 // any kind (#include, #import, etc.) has been processed, regardless
 // of whether the inclusion will actually result in an inclusion.
 void PPCallbacksTracker::InclusionDirective(
     clang::SourceLocation HashLoc, const clang::Token &IncludeTok,
     llvm::StringRef FileName, bool IsAngled,
     clang::CharSourceRange FilenameRange, const clang::FileEntry *File,
     llvm::StringRef SearchPath, llvm::StringRef RelativePath,
     const clang::Module *Imported) {
   beginCallback("InclusionDirective");
   appendArgument("IncludeTok", IncludeTok);
   appendFilePathArgument("FileName", FileName);
   appendArgument("IsAngled", IsAngled);
   appendArgument("FilenameRange", FilenameRange);
   appendArgument("File", File);
   appendFilePathArgument("SearchPath", SearchPath);
   appendFilePathArgument("RelativePath", RelativePath);
   appendArgument("Imported", Imported);
 }

 // Callback invoked whenever there was an explicit module-import
 // syntax.
 void PPCallbacksTracker::moduleImport(clang::SourceLocation ImportLoc,
                                       clang::ModuleIdPath Path,
                                       const clang::Module *Imported) {
   beginCallback("moduleImport");
   appendArgument("ImportLoc", ImportLoc);
   appendArgument("Path", Path);
   appendArgument("Imported", Imported);
 }

 // Callback invoked when the end of the main file is reached.
 // No subsequent callbacks will be made.
 void PPCallbacksTracker::EndOfMainFile() { beginCallback("EndOfMainFile"); }

 // Callback invoked when a #ident or #sccs directive is read.
 void PPCallbacksTracker::Ident(clang::SourceLocation Loc,
                                const std::string &Str) {
   beginCallback("Ident");
   appendArgument("Loc", Loc);
   appendArgument("Str", Str);
 }

 // Callback invoked when start reading any pragma directive.
 void
 PPCallbacksTracker::PragmaDirective(clang::SourceLocation Loc,
                                     clang::PragmaIntroducerKind Introducer) {
   beginCallback("PragmaDirective");
   appendArgument("Loc", Loc);
   appendArgument("Introducer", Introducer, PragmaIntroducerKindStrings);
 }

 // Callback invoked when a #pragma comment directive is read.
 void PPCallbacksTracker::PragmaComment(clang::SourceLocation Loc,
                                        const clang::IdentifierInfo *Kind,
                                        const std::string &Str) {
   beginCallback("PragmaComment");
   appendArgument("Loc", Loc);
   appendArgument("Kind", Kind);
   appendArgument("Str", Str);
 }

 // Callback invoked when a #pragma detect_mismatch directive is
 // read.
 void PPCallbacksTracker::PragmaDetectMismatch(clang::SourceLocation Loc,
                                               const std::string &Name,
                                               const std::string &Value) {
   beginCallback("PragmaDetectMismatch");
   appendArgument("Loc", Loc);
   appendArgument("Name", Name);
   appendArgument("Value", Value);
 }

 // Callback invoked when a #pragma clang __debug directive is read.
 void PPCallbacksTracker::PragmaDebug(clang::SourceLocation Loc,
                                      llvm::StringRef DebugType) {
   beginCallback("PragmaDebug");
   appendArgument("Loc", Loc);
   appendArgument("DebugType", DebugType);
 }

 // Callback invoked when a #pragma message directive is read.
 void PPCallbacksTracker::PragmaMessage(
     clang::SourceLocation Loc, llvm::StringRef Namespace,
     clang::PPCallbacks::PragmaMessageKind Kind, llvm::StringRef Str) {
   beginCallback("PragmaMessage");
   appendArgument("Loc", Loc);
   appendArgument("Namespace", Namespace);
   appendArgument("Kind", Kind, PragmaMessageKindStrings);
   appendArgument("Str", Str);
 }

 // Callback invoked when a #pragma gcc dianostic push directive
 // is read.
 void PPCallbacksTracker::PragmaDiagnosticPush(clang::SourceLocation Loc,
                                               llvm::StringRef Namespace) {
   beginCallback("PragmaDiagnosticPush");
   appendArgument("Loc", Loc);
   appendArgument("Namespace", Namespace);
 }

 // Callback invoked when a #pragma gcc dianostic pop directive
 // is read.
 void PPCallbacksTracker::PragmaDiagnosticPop(clang::SourceLocation Loc,
                                              llvm::StringRef Namespace) {
   beginCallback("PragmaDiagnosticPop");
   appendArgument("Loc", Loc);
   appendArgument("Namespace", Namespace);
 }

 // Callback invoked when a #pragma gcc dianostic directive is read.
 void PPCallbacksTracker::PragmaDiagnostic(clang::SourceLocation Loc,
                                           llvm::StringRef Namespace,
                                           clang::diag::Severity Mapping,
                                           llvm::StringRef Str) {
   beginCallback("PragmaDiagnostic");
   appendArgument("Loc", Loc);
   appendArgument("Namespace", Namespace);
   appendArgument("Mapping", (unsigned)Mapping, MappingStrings);
   appendArgument("Str", Str);
 }

 // Called when an OpenCL extension is either disabled or
 // enabled with a pragma.
 void PPCallbacksTracker::PragmaOpenCLExtension(
     clang::SourceLocation NameLoc, const clang::IdentifierInfo *Name,
     clang::SourceLocation StateLoc, unsigned State) {
   beginCallback("PragmaOpenCLExtension");
   appendArgument("NameLoc", NameLoc);
   appendArgument("Name", Name);
   appendArgument("StateLoc", StateLoc);
   appendArgument("State", (int)State);
 }

 // Callback invoked when a #pragma warning directive is read.
 void PPCallbacksTracker::PragmaWarning(clang::SourceLocation Loc,
                                        llvm::StringRef WarningSpec,
                                        llvm::ArrayRef<int> Ids) {
   beginCallback("PragmaWarning");
   appendArgument("Loc", Loc);
   appendArgument("WarningSpec", WarningSpec);

   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << "[";
   for (int i = 0, e = Ids.size(); i != e; ++i) {
     if (i)
       SS << ", ";
     SS << Ids[i];
   }
   SS << "]";
   appendArgument("Ids", SS.str());
 }

 // Callback invoked when a #pragma warning(push) directive is read.
 void PPCallbacksTracker::PragmaWarningPush(clang::SourceLocation Loc,
                                            int Level) {
   beginCallback("PragmaWarningPush");
   appendArgument("Loc", Loc);
   appendArgument("Level", Level);
 }

 // Callback invoked when a #pragma warning(pop) directive is read.
 void PPCallbacksTracker::PragmaWarningPop(clang::SourceLocation Loc) {
   beginCallback("PragmaWarningPop");
   appendArgument("Loc", Loc);
 }

 // Called by Preprocessor::HandleMacroExpandedIdentifier when a
 // macro invocation is found.
 void
 PPCallbacksTracker::MacroExpands(const clang::Token &MacroNameTok,
                                  const clang::MacroDirective *MacroDirective,
                                  clang::SourceRange Range,
                                  const clang::MacroArgs *Args) {
   beginCallback("MacroExpands");
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
   appendArgument("Range", Range);
   appendArgument("Args", Args);
 }

 // Hook called whenever a macro definition is seen.
 void
 PPCallbacksTracker::MacroDefined(const clang::Token &MacroNameTok,
                                  const clang::MacroDirective *MacroDirective) {
   beginCallback("MacroDefined");
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
 }

 // Hook called whenever a macro #undef is seen.
 void PPCallbacksTracker::MacroUndefined(
     const clang::Token &MacroNameTok,
     const clang::MacroDirective *MacroDirective) {
   beginCallback("MacroUndefined");
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
 }

 // Hook called whenever the 'defined' operator is seen.
 void PPCallbacksTracker::Defined(const clang::Token &MacroNameTok,
                                  const clang::MacroDirective *MacroDirective,
                                  clang::SourceRange Range) {
   beginCallback("Defined");
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
   appendArgument("Range", Range);
 }

 // Hook called when a source range is skipped.
 void PPCallbacksTracker::SourceRangeSkipped(clang::SourceRange Range) {
   beginCallback("SourceRangeSkipped");
   appendArgument("Range", Range);
 }

 // Hook called whenever an #if is seen.
 void PPCallbacksTracker::If(clang::SourceLocation Loc,
                             clang::SourceRange ConditionRange,
                             ConditionValueKind ConditionValue) {
   beginCallback("If");
   appendArgument("Loc", Loc);
   appendArgument("ConditionRange", ConditionRange);
   appendArgument("ConditionValue", ConditionValue, ConditionValueKindStrings);
 }

 // Hook called whenever an #elif is seen.
 void PPCallbacksTracker::Elif(clang::SourceLocation Loc,
                               clang::SourceRange ConditionRange,
                               ConditionValueKind ConditionValue,
                               clang::SourceLocation IfLoc) {
   beginCallback("Elif");
   appendArgument("Loc", Loc);
   appendArgument("ConditionRange", ConditionRange);
   appendArgument("ConditionValue", ConditionValue, ConditionValueKindStrings);
   appendArgument("IfLoc", IfLoc);
 }

 // Hook called whenever an #ifdef is seen.
 void PPCallbacksTracker::Ifdef(clang::SourceLocation Loc,
                                const clang::Token &MacroNameTok,
                                const clang::MacroDirective *MacroDirective) {
   beginCallback("Ifdef");
   appendArgument("Loc", Loc);
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
 }

 // Hook called whenever an #ifndef is seen.
 void PPCallbacksTracker::Ifndef(clang::SourceLocation Loc,
                                 const clang::Token &MacroNameTok,
                                 const clang::MacroDirective *MacroDirective) {
   beginCallback("Ifndef");
   appendArgument("Loc", Loc);
   appendArgument("MacroNameTok", MacroNameTok);
   appendArgument("MacroDirective", MacroDirective);
 }

 // Hook called whenever an #else is seen.
 void PPCallbacksTracker::Else(clang::SourceLocation Loc,
                               clang::SourceLocation IfLoc) {
   beginCallback("Else");
   appendArgument("Loc", Loc);
   appendArgument("IfLoc", IfLoc);
 }

 // Hook called whenever an #endif is seen.
 void PPCallbacksTracker::Endif(clang::SourceLocation Loc,
                                clang::SourceLocation IfLoc) {
   beginCallback("Endif");
   appendArgument("Loc", Loc);
   appendArgument("IfLoc", IfLoc);
 }

 // Helper functions.

 // Start a new callback.
 void PPCallbacksTracker::beginCallback(const char *Name) {
   DisableTrace = Ignore.count(std::string(Name));
   if (DisableTrace)
     return;
   CallbackCalls.push_back(CallbackCall(Name));
 }

 // Append a bool argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name, bool Value) {
   appendArgument(Name, (Value ? "true" : "false"));
 }

 // Append an int argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name, int Value) {
   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << Value;
   appendArgument(Name, SS.str());
 }

 // Append a string argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name, const char *Value) {
   if (DisableTrace)
     return;
   CallbackCalls.back().Arguments.push_back(Argument(Name, Value));
 }

 // Append a string object argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         llvm::StringRef Value) {
   appendArgument(Name, Value.str());
 }

 // Append a string object argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const std::string &Value) {
   appendArgument(Name, Value.c_str());
 }

 // Append a token argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::Token &Value) {
   appendArgument(Name, PP.getSpelling(Value));
 }

 // Append an enum argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name, int Value,
                                         const char *Strings[]) {
   appendArgument(Name, Strings[Value]);
 }

 // Append a FileID argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name, clang::FileID Value) {
   if (Value.isInvalid()) {
     appendArgument(Name, "(invalid)");
     return;
   }
   const clang::FileEntry *FileEntry =
       PP.getSourceManager().getFileEntryForID(Value);
   if (!FileEntry) {
     appendArgument(Name, "(getFileEntryForID failed)");
     return;
   }
   appendFilePathArgument(Name, FileEntry->getName());
 }

 // Append a FileEntry argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::FileEntry *Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
   appendFilePathArgument(Name, Value->getName());
 }

 // Append a SourceLocation argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         clang::SourceLocation Value) {
   if (Value.isInvalid()) {
     appendArgument(Name, "(invalid)");
     return;
   }
   appendArgument(Name, getSourceLocationString(PP, Value).c_str());
 }

 // Append a SourceRange argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         clang::SourceRange Value) {
   if (DisableTrace)
     return;
   if (Value.isInvalid()) {
     appendArgument(Name, "(invalid)");
     return;
   }
   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << "[" << getSourceLocationString(PP, Value.getBegin()) << ", "
      << getSourceLocationString(PP, Value.getEnd()) << "]";
   appendArgument(Name, SS.str());
 }

 // Append a CharSourceRange argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         clang::CharSourceRange Value) {
   if (Value.isInvalid()) {
     appendArgument(Name, "(invalid)");
     return;
   }
   appendArgument(Name, getSourceString(Value).str().c_str());
 }

 // Append a SourceLocation argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         clang::ModuleIdPath Value) {
   if (DisableTrace)
     return;
   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << "[";
   for (int I = 0, E = Value.size(); I != E; ++I) {
     if (I)
       SS << ", ";
     SS << "{"
        << "Name: " << Value[I].first->getName() << ", "
        << "Loc: " << getSourceLocationString(PP, Value[I].second) << "}";
   }
   SS << "]";
   appendArgument(Name, SS.str());
 }

 // Append an IdentifierInfo argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::IdentifierInfo *Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
   appendArgument(Name, Value->getName().str().c_str());
 }

 // Append a MacroDirective argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::MacroDirective *Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
   appendArgument(Name, MacroDirectiveKindStrings[Value->getKind()]);
 }

 // Append a MacroArgs argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::MacroArgs *Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << "[";
   // The argument tokens might include end tokens, so we reflect how
   // how getUnexpArgument provides the arguments.
   for (int I = 0, E = Value->getNumArguments(); I < E; ++I) {
     const clang::Token *Current = Value->getUnexpArgument(I);
     int TokenCount = Value->getArgLength(Current) + 1; // include EOF
     E -= TokenCount;
     if (I)
       SS << ", ";
     // We're assuming tokens are contiguous, as otherwise we have no
     // other way to get at them.
     --TokenCount;
     for (int TokenIndex = 0; TokenIndex < TokenCount; ++TokenIndex, ++Current) {
       if (TokenIndex)
         SS << " ";
       // We need to be careful here because the arguments might not be legal in
       // YAML, so we use the token name for anything but identifiers and
       // numeric literals.
       if (Current->isAnyIdentifier() ||
           Current->is(clang::tok::numeric_constant)) {
         SS << PP.getSpelling(*Current);
       } else {
         SS << "<" << Current->getName() << ">";
       }
     }
   }
   SS << "]";
   appendArgument(Name, SS.str());
 }

 // Append a Module argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
                                         const clang::Module *Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
   appendArgument(Name, Value->Name.c_str());
 }

 // Append a double-quoted argument to the top trace item.
 void PPCallbacksTracker::appendQuotedArgument(const char *Name,
                                               const std::string &Value) {
   std::string Str;
   llvm::raw_string_ostream SS(Str);
   SS << "\"" << Value << "\"";
   appendArgument(Name, SS.str());
 }

 // Append a double-quoted file path argument to the top trace item.
 void PPCallbacksTracker::appendFilePathArgument(const char *Name,
                                                 llvm::StringRef Value) {
   std::string Path(Value);
   // YAML treats backslash as escape, so use forward slashes.
   std::replace(Path.begin(), Path.end(), '\\', '/');
   appendQuotedArgument(Name, Path);
 }

 // Get the raw source string of the range.
 llvm::StringRef
 PPCallbacksTracker::getSourceString(clang::CharSourceRange Range) {
   const char *B = PP.getSourceManager().getCharacterData(Range.getBegin());
   const char *E = PP.getSourceManager().getCharacterData(Range.getEnd());
   return llvm::StringRef(B, E - B);
 }
	//===--- PPCallbacksTracker.cpp - Preprocessor tracker ----------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===--------------------------------------------------------------------===//
	///
	/// \file
	/// \brief Implementations for preprocessor tracking.
	///
	/// See the header for details.
	///
	//===--------------------------------------------------------------------===//

	#include "PPCallbacksTracker.h"
	#include "clang/Lex/MacroArgs.h"
	#include "llvm/Support/raw_ostream.h"
	#include <stdarg.h>
	#include <stdio.h>

	// Utility functions.

	// Get a "file:line:column" source location string.
	static std::string getSourceLocationString(clang::Preprocessor &PP,
	clang::SourceLocation Loc) {
	if (Loc.isInvalid())
	return std::string("(none)");

	if (Loc.isFileID()) {
	clang::PresumedLoc PLoc = PP.getSourceManager().getPresumedLoc(Loc);

	if (PLoc.isInvalid()) {
	return std::string("(invalid)");
	}

	std::string Str;
	llvm::raw_string_ostream SS(Str);

	// The macro expansion and spelling pos is identical for file locs.
	SS << "\"" << PLoc.getFilename() << ':' << PLoc.getLine() << ':'
	<< PLoc.getColumn() << "\"";

	std::string Result = SS.str();

	// YAML treats backslash as escape, so use forward slashes.
	std::replace(Result.begin(), Result.end(), '\\', '/');

	return Result;
	}

	return std::string("(nonfile)");
	}

	// Enum string tables.

	// FileChangeReason strings.
	static const char *FileChangeReasonStrings[] = {
	"EnterFile", "ExitFile", "SystemHeaderPragma", "RenameFile"
	};

	// CharacteristicKind strings.
	static const char *CharacteristicKindStrings[] = { "C_User", "C_System",
	"C_ExternCSystem" };

	// MacroDirective::Kind strings.
	static const char *MacroDirectiveKindStrings[] = { "MD_Define", "MD_Undefine",
	"MD_Visibility" };

	// PragmaIntroducerKind strings.
	static const char *PragmaIntroducerKindStrings[] = { "PIK_HashPragma",
	"PIK__Pragma",
	"PIK___pragma" };

	// PragmaMessageKind strings.
	static const char *PragmaMessageKindStrings[] = { "PMK_Message", "PMK_Warning",
	"PMK_Error" };

	// ConditionValueKind strings.
	const char *
	ConditionValueKindStrings[] = {
	"CVK_NotEvaluated", "CVK_False", "CVK_True"
	};

	// Mapping strings.
	static const char *MappingStrings[] = { "0", "MAP_IGNORE",
	"MAP_REMARK", "MAP_WARNING",
	"MAP_ERROR", "MAP_FATAL" };

	// PPCallbacksTracker functions.

	PPCallbacksTracker::PPCallbacksTracker(llvm::SmallSet<std::string, 4> &Ignore,
	std::vector<CallbackCall> &CallbackCalls,
	clang::Preprocessor &PP)
	: CallbackCalls(CallbackCalls), Ignore(Ignore), PP(PP) {}

	PPCallbacksTracker::~PPCallbacksTracker() {}

	// Callback functions.

	// Callback invoked whenever a source file is entered or exited.
	void PPCallbacksTracker::FileChanged(
	clang::SourceLocation Loc, clang::PPCallbacks::FileChangeReason Reason,
	clang::SrcMgr::CharacteristicKind FileType, clang::FileID PrevFID) {
	beginCallback("FileChanged");
	appendArgument("Loc", Loc);
	appendArgument("Reason", Reason, FileChangeReasonStrings);
	appendArgument("FileType", FileType, CharacteristicKindStrings);
	appendArgument("PrevFID", PrevFID);
	}

	// Callback invoked whenever a source file is skipped as the result
	// of header guard optimization.
	void
	PPCallbacksTracker::FileSkipped(const clang::FileEntry &ParentFile,
	const clang::Token &FilenameTok,
	clang::SrcMgr::CharacteristicKind FileType) {
	beginCallback("FileSkipped");
	appendArgument("ParentFile", &ParentFile);
	appendArgument("FilenameTok", FilenameTok);
	appendArgument("FileType", FileType, CharacteristicKindStrings);
	}

	// Callback invoked whenever an inclusion directive results in a
	// file-not-found error.
	bool
	PPCallbacksTracker::FileNotFound(llvm::StringRef FileName,
	llvm::SmallVectorImpl<char> &RecoveryPath) {
	beginCallback("FileNotFound");
	appendFilePathArgument("FileName", FileName);
	return false;
	}

	// Callback invoked whenever an inclusion directive of
	// any kind (#include, #import, etc.) has been processed, regardless
	// of whether the inclusion will actually result in an inclusion.
	void PPCallbacksTracker::InclusionDirective(
	clang::SourceLocation HashLoc, const clang::Token &IncludeTok,
	llvm::StringRef FileName, bool IsAngled,
	clang::CharSourceRange FilenameRange, const clang::FileEntry *File,
	llvm::StringRef SearchPath, llvm::StringRef RelativePath,
	const clang::Module *Imported) {
	beginCallback("InclusionDirective");
	appendArgument("IncludeTok", IncludeTok);
	appendFilePathArgument("FileName", FileName);
	appendArgument("IsAngled", IsAngled);
	appendArgument("FilenameRange", FilenameRange);
	appendArgument("File", File);
	appendFilePathArgument("SearchPath", SearchPath);
	appendFilePathArgument("RelativePath", RelativePath);
	appendArgument("Imported", Imported);
	}

	// Callback invoked whenever there was an explicit module-import
	// syntax.
	void PPCallbacksTracker::moduleImport(clang::SourceLocation ImportLoc,
	clang::ModuleIdPath Path,
	const clang::Module *Imported) {
	beginCallback("moduleImport");
	appendArgument("ImportLoc", ImportLoc);
	appendArgument("Path", Path);
	appendArgument("Imported", Imported);
	}

	// Callback invoked when the end of the main file is reached.
	// No subsequent callbacks will be made.
	void PPCallbacksTracker::EndOfMainFile() { beginCallback("EndOfMainFile"); }

	// Callback invoked when a #ident or #sccs directive is read.
	void PPCallbacksTracker::Ident(clang::SourceLocation Loc,
	const std::string &Str) {
	beginCallback("Ident");
	appendArgument("Loc", Loc);
	appendArgument("Str", Str);
	}

	// Callback invoked when start reading any pragma directive.
	void
	PPCallbacksTracker::PragmaDirective(clang::SourceLocation Loc,
	clang::PragmaIntroducerKind Introducer) {
	beginCallback("PragmaDirective");
	appendArgument("Loc", Loc);
	appendArgument("Introducer", Introducer, PragmaIntroducerKindStrings);
	}

	// Callback invoked when a #pragma comment directive is read.
	void PPCallbacksTracker::PragmaComment(clang::SourceLocation Loc,
	const clang::IdentifierInfo *Kind,
	const std::string &Str) {
	beginCallback("PragmaComment");
	appendArgument("Loc", Loc);
	appendArgument("Kind", Kind);
	appendArgument("Str", Str);
	}

	// Callback invoked when a #pragma detect_mismatch directive is
	// read.
	void PPCallbacksTracker::PragmaDetectMismatch(clang::SourceLocation Loc,
	const std::string &Name,
	const std::string &Value) {
	beginCallback("PragmaDetectMismatch");
	appendArgument("Loc", Loc);
	appendArgument("Name", Name);
	appendArgument("Value", Value);
	}

	// Callback invoked when a #pragma clang __debug directive is read.
	void PPCallbacksTracker::PragmaDebug(clang::SourceLocation Loc,
	llvm::StringRef DebugType) {
	beginCallback("PragmaDebug");
	appendArgument("Loc", Loc);
	appendArgument("DebugType", DebugType);
	}

	// Callback invoked when a #pragma message directive is read.
	void PPCallbacksTracker::PragmaMessage(
	clang::SourceLocation Loc, llvm::StringRef Namespace,
	clang::PPCallbacks::PragmaMessageKind Kind, llvm::StringRef Str) {
	beginCallback("PragmaMessage");
	appendArgument("Loc", Loc);
	appendArgument("Namespace", Namespace);
	appendArgument("Kind", Kind, PragmaMessageKindStrings);
	appendArgument("Str", Str);
	}

	// Callback invoked when a #pragma gcc dianostic push directive
	// is read.
	void PPCallbacksTracker::PragmaDiagnosticPush(clang::SourceLocation Loc,
	llvm::StringRef Namespace) {
	beginCallback("PragmaDiagnosticPush");
	appendArgument("Loc", Loc);
	appendArgument("Namespace", Namespace);
	}

	// Callback invoked when a #pragma gcc dianostic pop directive
	// is read.
	void PPCallbacksTracker::PragmaDiagnosticPop(clang::SourceLocation Loc,
	llvm::StringRef Namespace) {
	beginCallback("PragmaDiagnosticPop");
	appendArgument("Loc", Loc);
	appendArgument("Namespace", Namespace);
	}

	// Callback invoked when a #pragma gcc dianostic directive is read.
	void PPCallbacksTracker::PragmaDiagnostic(clang::SourceLocation Loc,
	llvm::StringRef Namespace,
	clang::diag::Severity Mapping,
	llvm::StringRef Str) {
	beginCallback("PragmaDiagnostic");
	appendArgument("Loc", Loc);
	appendArgument("Namespace", Namespace);
	appendArgument("Mapping", (unsigned)Mapping, MappingStrings);
	appendArgument("Str", Str);
	}

	// Called when an OpenCL extension is either disabled or
	// enabled with a pragma.
	void PPCallbacksTracker::PragmaOpenCLExtension(
	clang::SourceLocation NameLoc, const clang::IdentifierInfo *Name,
	clang::SourceLocation StateLoc, unsigned State) {
	beginCallback("PragmaOpenCLExtension");
	appendArgument("NameLoc", NameLoc);
	appendArgument("Name", Name);
	appendArgument("StateLoc", StateLoc);
	appendArgument("State", (int)State);
	}

	// Callback invoked when a #pragma warning directive is read.
	void PPCallbacksTracker::PragmaWarning(clang::SourceLocation Loc,
	llvm::StringRef WarningSpec,
	llvm::ArrayRef<int> Ids) {
	beginCallback("PragmaWarning");
	appendArgument("Loc", Loc);
	appendArgument("WarningSpec", WarningSpec);

	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << "[";
	for (int i = 0, e = Ids.size(); i != e; ++i) {
	if (i)
	SS << ", ";
	SS << Ids[i];
	}
	SS << "]";
	appendArgument("Ids", SS.str());
	}

	// Callback invoked when a #pragma warning(push) directive is read.
	void PPCallbacksTracker::PragmaWarningPush(clang::SourceLocation Loc,
	int Level) {
	beginCallback("PragmaWarningPush");
	appendArgument("Loc", Loc);
	appendArgument("Level", Level);
	}

	// Callback invoked when a #pragma warning(pop) directive is read.
	void PPCallbacksTracker::PragmaWarningPop(clang::SourceLocation Loc) {
	beginCallback("PragmaWarningPop");
	appendArgument("Loc", Loc);
	}

	// Called by Preprocessor::HandleMacroExpandedIdentifier when a
	// macro invocation is found.
	void
	PPCallbacksTracker::MacroExpands(const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective,
	clang::SourceRange Range,
	const clang::MacroArgs *Args) {
	beginCallback("MacroExpands");
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	appendArgument("Range", Range);
	appendArgument("Args", Args);
	}

	// Hook called whenever a macro definition is seen.
	void
	PPCallbacksTracker::MacroDefined(const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective) {
	beginCallback("MacroDefined");
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	}

	// Hook called whenever a macro #undef is seen.
	void PPCallbacksTracker::MacroUndefined(
	const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective) {
	beginCallback("MacroUndefined");
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	}

	// Hook called whenever the 'defined' operator is seen.
	void PPCallbacksTracker::Defined(const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective,
	clang::SourceRange Range) {
	beginCallback("Defined");
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	appendArgument("Range", Range);
	}

	// Hook called when a source range is skipped.
	void PPCallbacksTracker::SourceRangeSkipped(clang::SourceRange Range) {
	beginCallback("SourceRangeSkipped");
	appendArgument("Range", Range);
	}

	// Hook called whenever an #if is seen.
	void PPCallbacksTracker::If(clang::SourceLocation Loc,
	clang::SourceRange ConditionRange,
	ConditionValueKind ConditionValue) {
	beginCallback("If");
	appendArgument("Loc", Loc);
	appendArgument("ConditionRange", ConditionRange);
	appendArgument("ConditionValue", ConditionValue, ConditionValueKindStrings);
	}

	// Hook called whenever an #elif is seen.
	void PPCallbacksTracker::Elif(clang::SourceLocation Loc,
	clang::SourceRange ConditionRange,
	ConditionValueKind ConditionValue,
	clang::SourceLocation IfLoc) {
	beginCallback("Elif");
	appendArgument("Loc", Loc);
	appendArgument("ConditionRange", ConditionRange);
	appendArgument("ConditionValue", ConditionValue, ConditionValueKindStrings);
	appendArgument("IfLoc", IfLoc);
	}

	// Hook called whenever an #ifdef is seen.
	void PPCallbacksTracker::Ifdef(clang::SourceLocation Loc,
	const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective) {
	beginCallback("Ifdef");
	appendArgument("Loc", Loc);
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	}

	// Hook called whenever an #ifndef is seen.
	void PPCallbacksTracker::Ifndef(clang::SourceLocation Loc,
	const clang::Token &MacroNameTok,
	const clang::MacroDirective *MacroDirective) {
	beginCallback("Ifndef");
	appendArgument("Loc", Loc);
	appendArgument("MacroNameTok", MacroNameTok);
	appendArgument("MacroDirective", MacroDirective);
	}

	// Hook called whenever an #else is seen.
	void PPCallbacksTracker::Else(clang::SourceLocation Loc,
	clang::SourceLocation IfLoc) {
	beginCallback("Else");
	appendArgument("Loc", Loc);
	appendArgument("IfLoc", IfLoc);
	}

	// Hook called whenever an #endif is seen.
	void PPCallbacksTracker::Endif(clang::SourceLocation Loc,
	clang::SourceLocation IfLoc) {
	beginCallback("Endif");
	appendArgument("Loc", Loc);
	appendArgument("IfLoc", IfLoc);
	}

	// Helper functions.

	// Start a new callback.
	void PPCallbacksTracker::beginCallback(const char *Name) {
	DisableTrace = Ignore.count(std::string(Name));
	if (DisableTrace)
	return;
	CallbackCalls.push_back(CallbackCall(Name));
	}

	// Append a bool argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name, bool Value) {
	appendArgument(Name, (Value ? "true" : "false"));
	}

	// Append an int argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name, int Value) {
	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << Value;
	appendArgument(Name, SS.str());
	}

	// Append a string argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char Name, const char Value) {
	if (DisableTrace)
	return;
	CallbackCalls.back().Arguments.push_back(Argument(Name, Value));
	}

	// Append a string object argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	llvm::StringRef Value) {
	appendArgument(Name, Value.str());
	}

	// Append a string object argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const std::string &Value) {
	appendArgument(Name, Value.c_str());
	}

	// Append a token argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::Token &Value) {
	appendArgument(Name, PP.getSpelling(Value));
	}

	// Append an enum argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name, int Value,
	const char *Strings[]) {
	appendArgument(Name, Strings[Value]);
	}

	// Append a FileID argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name, clang::FileID Value) {
	if (Value.isInvalid()) {
	appendArgument(Name, "(invalid)");
	return;
	}
	const clang::FileEntry *FileEntry =
	PP.getSourceManager().getFileEntryForID(Value);
	if (!FileEntry) {
	appendArgument(Name, "(getFileEntryForID failed)");
	return;
	}
	appendFilePathArgument(Name, FileEntry->getName());
	}

	// Append a FileEntry argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::FileEntry *Value) {
	if (!Value) {
	appendArgument(Name, "(null)");
	return;
	}
	appendFilePathArgument(Name, Value->getName());
	}

	// Append a SourceLocation argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	clang::SourceLocation Value) {
	if (Value.isInvalid()) {
	appendArgument(Name, "(invalid)");
	return;
	}
	appendArgument(Name, getSourceLocationString(PP, Value).c_str());
	}

	// Append a SourceRange argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	clang::SourceRange Value) {
	if (DisableTrace)
	return;
	if (Value.isInvalid()) {
	appendArgument(Name, "(invalid)");
	return;
	}
	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << "[" << getSourceLocationString(PP, Value.getBegin()) << ", "
	<< getSourceLocationString(PP, Value.getEnd()) << "]";
	appendArgument(Name, SS.str());
	}

	// Append a CharSourceRange argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	clang::CharSourceRange Value) {
	if (Value.isInvalid()) {
	appendArgument(Name, "(invalid)");
	return;
	}
	appendArgument(Name, getSourceString(Value).str().c_str());
	}

	// Append a SourceLocation argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	clang::ModuleIdPath Value) {
	if (DisableTrace)
	return;
	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << "[";
	for (int I = 0, E = Value.size(); I != E; ++I) {
	if (I)
	SS << ", ";
	SS << "{"
	<< "Name: " << Value[I].first->getName() << ", "
	<< "Loc: " << getSourceLocationString(PP, Value[I].second) << "}";
	}
	SS << "]";
	appendArgument(Name, SS.str());
	}

	// Append an IdentifierInfo argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::IdentifierInfo *Value) {
	if (!Value) {
	appendArgument(Name, "(null)");
	return;
	}
	appendArgument(Name, Value->getName().str().c_str());
	}

	// Append a MacroDirective argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::MacroDirective *Value) {
	if (!Value) {
	appendArgument(Name, "(null)");
	return;
	}
	appendArgument(Name, MacroDirectiveKindStrings[Value->getKind()]);
	}

	// Append a MacroArgs argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::MacroArgs *Value) {
	if (!Value) {
	appendArgument(Name, "(null)");
	return;
	}
	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << "[";
	// The argument tokens might include end tokens, so we reflect how
	// how getUnexpArgument provides the arguments.
	for (int I = 0, E = Value->getNumArguments(); I < E; ++I) {
	const clang::Token *Current = Value->getUnexpArgument(I);
	int TokenCount = Value->getArgLength(Current) + 1; // include EOF
	E -= TokenCount;
	if (I)
	SS << ", ";
	// We're assuming tokens are contiguous, as otherwise we have no
	// other way to get at them.
	--TokenCount;
	for (int TokenIndex = 0; TokenIndex < TokenCount; ++TokenIndex, ++Current) {
	if (TokenIndex)
	SS << " ";
	// We need to be careful here because the arguments might not be legal in
	// YAML, so we use the token name for anything but identifiers and
	// numeric literals.
	if (Current->isAnyIdentifier() \|\|
	Current->is(clang::tok::numeric_constant)) {
	SS << PP.getSpelling(*Current);
	} else {
	SS << "<" << Current->getName() << ">";
	}
	}
	}
	SS << "]";
	appendArgument(Name, SS.str());
	}

	// Append a Module argument to the top trace item.
	void PPCallbacksTracker::appendArgument(const char *Name,
	const clang::Module *Value) {
	if (!Value) {
	appendArgument(Name, "(null)");
	return;
	}
	appendArgument(Name, Value->Name.c_str());
	}

	// Append a double-quoted argument to the top trace item.
	void PPCallbacksTracker::appendQuotedArgument(const char *Name,
	const std::string &Value) {
	std::string Str;
	llvm::raw_string_ostream SS(Str);
	SS << "\"" << Value << "\"";
	appendArgument(Name, SS.str());
	}

	// Append a double-quoted file path argument to the top trace item.
	void PPCallbacksTracker::appendFilePathArgument(const char *Name,
	llvm::StringRef Value) {
	std::string Path(Value);
	// YAML treats backslash as escape, so use forward slashes.
	std::replace(Path.begin(), Path.end(), '\\', '/');
	appendQuotedArgument(Name, Path);
	}

	// Get the raw source string of the range.
	llvm::StringRef
	PPCallbacksTracker::getSourceString(clang::CharSourceRange Range) {
	const char *B = PP.getSourceManager().getCharacterData(Range.getBegin());
	const char *E = PP.getSourceManager().getCharacterData(Range.getEnd());
	return llvm::StringRef(B, E - B);
	}