tools/driver/driver.cpp - platform/external/clang - Gitiles

 //===-- driver.cpp - Clang GCC-Compatible Driver --------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This is the entry point to the clang driver; it is a thin wrapper
 // for functionality in the Driver clang library.
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/Option.h"
 #include "clang/Frontend/DiagnosticOptions.h"
 #include "clang/Frontend/TextDiagnosticPrinter.h"

 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/system_error.h"
 #include "llvm/Target/TargetRegistry.h"
 #include "llvm/Target/TargetSelect.h"
 #include <cctype>
 using namespace clang;
 using namespace clang::driver;

 llvm::sys::Path GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
   if (!CanonicalPrefixes)
     return llvm::sys::Path(Argv0);

   // This just needs to be some symbol in the binary; C++ doesn't
   // allow taking the address of ::main however.
   void *P = (void*) (intptr_t) GetExecutablePath;
   return llvm::sys::Path::GetMainExecutable(Argv0, P);
 }

 static const char *SaveStringInSet(std::set<std::string> &SavedStrings,
                                    llvm::StringRef S) {
   return SavedStrings.insert(S).first->c_str();
 }

 /// ApplyQAOverride - Apply a list of edits to the input argument lists.
 ///
 /// The input string is a space separate list of edits to perform,
 /// they are applied in order to the input argument lists. Edits
 /// should be one of the following forms:
 ///
 ///  '#': Silence information about the changes to the command line arguments.
 ///
 ///  '^': Add FOO as a new argument at the beginning of the command line.
 ///
 ///  '+': Add FOO as a new argument at the end of the command line.
 ///
 ///  's/XXX/YYY/': Substitute the regular expression XXX with YYY in the command
 ///  line.
 ///
 ///  'xOPTION': Removes all instances of the literal argument OPTION.
 ///
 ///  'XOPTION': Removes all instances of the literal argument OPTION,
 ///  and the following argument.
 ///
 ///  'Ox': Removes all flags matching 'O' or 'O[sz0-9]' and adds 'Ox'
 ///  at the end of the command line.
 ///
 /// \param OS - The stream to write edit information to.
 /// \param Args - The vector of command line arguments.
 /// \param Edit - The override command to perform.
 /// \param SavedStrings - Set to use for storing string representations.
 static void ApplyOneQAOverride(llvm::raw_ostream &OS,
                                llvm::SmallVectorImpl<const char*> &Args,
                                llvm::StringRef Edit,
                                std::set<std::string> &SavedStrings) {
   // This does not need to be efficient.

   if (Edit[0] == '^') {
     const char *Str =
       SaveStringInSet(SavedStrings, Edit.substr(1));
     OS << "### Adding argument " << Str << " at beginning\n";
     Args.insert(Args.begin() + 1, Str);
   } else if (Edit[0] == '+') {
     const char *Str =
       SaveStringInSet(SavedStrings, Edit.substr(1));
     OS << "### Adding argument " << Str << " at end\n";
     Args.push_back(Str);
   } else if (Edit[0] == 's' && Edit[1] == '/' && Edit.endswith("/") &&
              Edit.slice(2, Edit.size()-1).find('/') != llvm::StringRef::npos) {
     llvm::StringRef MatchPattern = Edit.substr(2).split('/').first;
     llvm::StringRef ReplPattern = Edit.substr(2).split('/').second;
     ReplPattern = ReplPattern.slice(0, ReplPattern.size()-1);

     for (unsigned i = 1, e = Args.size(); i != e; ++i) {
       std::string Repl = llvm::Regex(MatchPattern).sub(ReplPattern, Args[i]);

       if (Repl != Args[i]) {
         OS << "### Replacing '" << Args[i] << "' with '" << Repl << "'\n";
         Args[i] = SaveStringInSet(SavedStrings, Repl);
       }
     }
   } else if (Edit[0] == 'x' || Edit[0] == 'X') {
     std::string Option = Edit.substr(1, std::string::npos);
     for (unsigned i = 1; i < Args.size();) {
       if (Option == Args[i]) {
         OS << "### Deleting argument " << Args[i] << '\n';
         Args.erase(Args.begin() + i);
         if (Edit[0] == 'X') {
           if (i < Args.size()) {
             OS << "### Deleting argument " << Args[i] << '\n';
             Args.erase(Args.begin() + i);
           } else
             OS << "### Invalid X edit, end of command line!\n";
         }
       } else
         ++i;
     }
   } else if (Edit[0] == 'O') {
     for (unsigned i = 1; i < Args.size();) {
       const char *A = Args[i];
       if (A[0] == '-' && A[1] == 'O' &&
           (A[2] == '\0' ||
            (A[3] == '\0' && (A[2] == 's' || A[2] == 'z' ||
                              ('0' <= A[2] && A[2] <= '9'))))) {
         OS << "### Deleting argument " << Args[i] << '\n';
         Args.erase(Args.begin() + i);
       } else
         ++i;
     }
     OS << "### Adding argument " << Edit << " at end\n";
     Args.push_back(SaveStringInSet(SavedStrings, '-' + Edit.str()));
   } else {
     OS << "### Unrecognized edit: " << Edit << "\n";
   }
 }

 /// ApplyQAOverride - Apply a comma separate list of edits to the
 /// input argument lists. See ApplyOneQAOverride.
 static void ApplyQAOverride(llvm::SmallVectorImpl<const char*> &Args,
                             const char *OverrideStr,
                             std::set<std::string> &SavedStrings) {
   llvm::raw_ostream *OS = &llvm::errs();

   if (OverrideStr[0] == '#') {
     ++OverrideStr;
     OS = &llvm::nulls();
   }

   *OS << "### QA_OVERRIDE_GCC3_OPTIONS: " << OverrideStr << "\n";

   // This does not need to be efficient.

   const char *S = OverrideStr;
   while (*S) {
     const char *End = ::strchr(S, ' ');
     if (!End)
       End = S + strlen(S);
     if (End != S)
       ApplyOneQAOverride(*OS, Args, std::string(S, End), SavedStrings);
     S = End;
     if (*S != '\0')
       ++S;
   }
 }

 extern int cc1_main(const char **ArgBegin, const char **ArgEnd,
                     const char *Argv0, void *MainAddr);
 extern int cc1as_main(const char **ArgBegin, const char **ArgEnd,
                       const char *Argv0, void *MainAddr);

 static void ExpandArgsFromBuf(const char *Arg,
                               llvm::SmallVectorImpl<const char*> &ArgVector,
                               std::set<std::string> &SavedStrings) {
   const char *FName = Arg + 1;
   llvm::OwningPtr<llvm::MemoryBuffer> MemBuf;
   if (llvm::MemoryBuffer::getFile(FName, MemBuf)) {
     ArgVector.push_back(SaveStringInSet(SavedStrings, Arg));
     return;
   }

   const char *Buf = MemBuf->getBufferStart();
   char InQuote = ' ';
   std::string CurArg;

   for (const char *P = Buf; ; ++P) {
     if (*P == '\0' || (isspace(*P) && InQuote == ' ')) {
       if (!CurArg.empty()) {

         if (CurArg[0] != '@') {
           ArgVector.push_back(SaveStringInSet(SavedStrings, CurArg));
         } else {
           ExpandArgsFromBuf(CurArg.c_str(), ArgVector, SavedStrings);
         }

         CurArg = "";
       }
       if (*P == '\0')
         break;
       else
         continue;
     }

     if (isspace(*P)) {
       if (InQuote != ' ')
         CurArg.push_back(*P);
       continue;
     }

     if (*P == '"' || *P == '\'') {
       if (InQuote == *P)
         InQuote = ' ';
       else if (InQuote == ' ')
         InQuote = *P;
       else
         CurArg.push_back(*P);
       continue;
     }

     if (*P == '\\') {
       ++P;
       if (*P != '\0')
         CurArg.push_back(*P);
       continue;
     }
     CurArg.push_back(*P);
   }
 }

 static void ExpandArgv(int argc, const char **argv,
                        llvm::SmallVectorImpl<const char*> &ArgVector,
                        std::set<std::string> &SavedStrings) {
   for (int i = 0; i < argc; ++i) {
     const char *Arg = argv[i];
     if (Arg[0] != '@') {
       ArgVector.push_back(SaveStringInSet(SavedStrings, std::string(Arg)));
       continue;
     }

     ExpandArgsFromBuf(Arg, ArgVector, SavedStrings);
   }
 }

 static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
                           std::set<std::string> &SavedStrings,
                           Driver &TheDriver)
 {
   // Try to infer frontend type and default target from the program name.

   // suffixes[] contains the list of known driver suffixes.
   // Suffixes are compared against the program name in order.
   // If there is a match, the frontend type is updated as necessary (CPP/C++).
   // If there is no match, a second round is done after stripping the last
   // hyphen and everything following it. This allows using something like
   // "clang++-2.9".

   // If there is a match in either the first or second round,
   // the function tries to identify a target as prefix. E.g.
   // "x86_64-linux-clang" as interpreted as suffix "clang" with
   // target prefix "x86_64-linux". If such a target prefix is found,
   // is gets added via -ccc-host-triple as implicit first argument.
   static const struct {
     const char *Suffix;
     bool IsCXX;
     bool IsCPP;
   } suffixes [] = {
     { "clang", false, false },
     { "clang++", true, false },
     { "clang-c++", true, false },
     { "clang-cc", false, false },
     { "clang-cpp", false, true },
     { "clang-g++", true, false },
     { "clang-gcc", false, false },
     { "cc", false, false },
     { "cpp", false, true },
     { "++", true, false },
   };
   std::string ProgName(llvm::sys::path::stem(ArgVector[0]));
   llvm::StringRef ProgNameRef(ProgName);
   llvm::StringRef Prefix;

   for (int Components = 2; Components; --Components) {
     bool FoundMatch = false;
     size_t i;

     for (i = 0; i < sizeof(suffixes) / sizeof(suffixes[0]); ++i) {
       if (ProgNameRef.endswith(suffixes[i].Suffix)) {
         FoundMatch = true;
         if (suffixes[i].IsCXX)
           TheDriver.CCCIsCXX = true;
         if (suffixes[i].IsCPP)
           TheDriver.CCCIsCPP = true;
         break;
       }
     }

     if (FoundMatch) {
       llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-',
         ProgNameRef.size() - strlen(suffixes[i].Suffix));
       if (LastComponent != llvm::StringRef::npos)
         Prefix = ProgNameRef.slice(0, LastComponent);
       break;
     }

     llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-');
     if (LastComponent == llvm::StringRef::npos)
       break;
     ProgNameRef = ProgNameRef.slice(0, LastComponent);
   }

   if (Prefix.empty())
     return;

   std::string IgnoredError;
   if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
     llvm::SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
     if (it != ArgVector.end())
       ++it;
     ArgVector.insert(it, SaveStringInSet(SavedStrings, Prefix));
     ArgVector.insert(it,
       SaveStringInSet(SavedStrings, std::string("-ccc-host-triple")));
   }
 }

 int main(int argc_, const char **argv_) {
   llvm::sys::PrintStackTraceOnErrorSignal();
   llvm::PrettyStackTraceProgram X(argc_, argv_);

   std::set<std::string> SavedStrings;
   llvm::SmallVector<const char*, 256> argv;

   ExpandArgv(argc_, argv_, argv, SavedStrings);

   // Handle -cc1 integrated tools.
   if (argv.size() > 1 && llvm::StringRef(argv[1]).startswith("-cc1")) {
     llvm::StringRef Tool = argv[1] + 4;

     if (Tool == "")
       return cc1_main(argv.data()+2, argv.data()+argv.size(), argv[0],
                       (void*) (intptr_t) GetExecutablePath);
     if (Tool == "as")
       return cc1as_main(argv.data()+2, argv.data()+argv.size(), argv[0],
                       (void*) (intptr_t) GetExecutablePath);

     // Reject unknown tools.
     llvm::errs() << "error: unknown integrated tool '" << Tool << "'\n";
     return 1;
   }

   bool CanonicalPrefixes = true;
   for (int i = 1, size = argv.size(); i < size; ++i) {
     if (llvm::StringRef(argv[i]) == "-no-canonical-prefixes") {
       CanonicalPrefixes = false;
       break;
     }
   }

   llvm::sys::Path Path = GetExecutablePath(argv[0], CanonicalPrefixes);

   TextDiagnosticPrinter *DiagClient
     = new TextDiagnosticPrinter(llvm::errs(), DiagnosticOptions());
   DiagClient->setPrefix(llvm::sys::path::stem(Path.str()));
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
   Diagnostic Diags(DiagID, DiagClient);

 #ifdef CLANG_IS_PRODUCTION
   const bool IsProduction = true;
 #  ifdef CLANGXX_IS_PRODUCTION
   const bool CXXIsProduction = true;
 #  else
   const bool CXXIsProduction = false;
 #  endif
 #else
   const bool IsProduction = false;
   const bool CXXIsProduction = false;
 #endif
   Driver TheDriver(Path.str(), llvm::sys::getHostTriple(),
                    "a.out", IsProduction, CXXIsProduction,
                    Diags);

   // Attempt to find the original path used to invoke the driver, to determine
   // the installed path. We do this manually, because we want to support that
   // path being a symlink.
   {
     llvm::SmallString<128> InstalledPath(argv[0]);

     // Do a PATH lookup, if there are no directory components.
     if (llvm::sys::path::filename(InstalledPath) == InstalledPath) {
       llvm::sys::Path Tmp = llvm::sys::Program::FindProgramByName(
         llvm::sys::path::filename(InstalledPath.str()));
       if (!Tmp.empty())
         InstalledPath = Tmp.str();
     }
     llvm::sys::fs::make_absolute(InstalledPath);
     InstalledPath = llvm::sys::path::parent_path(InstalledPath);
     bool exists;
     if (!llvm::sys::fs::exists(InstalledPath.str(), exists) && exists)
       TheDriver.setInstalledDir(InstalledPath);
   }

   llvm::InitializeAllTargets();
   ParseProgName(argv, SavedStrings, TheDriver);

   // Handle CC_PRINT_OPTIONS and CC_PRINT_OPTIONS_FILE.
   TheDriver.CCPrintOptions = !!::getenv("CC_PRINT_OPTIONS");
   if (TheDriver.CCPrintOptions)
     TheDriver.CCPrintOptionsFilename = ::getenv("CC_PRINT_OPTIONS_FILE");

   // Handle CC_PRINT_HEADERS and CC_PRINT_HEADERS_FILE.
   TheDriver.CCPrintHeaders = !!::getenv("CC_PRINT_HEADERS");
   if (TheDriver.CCPrintHeaders)
     TheDriver.CCPrintHeadersFilename = ::getenv("CC_PRINT_HEADERS_FILE");

   // Handle CC_LOG_DIAGNOSTICS and CC_LOG_DIAGNOSTICS_FILE.
   TheDriver.CCLogDiagnostics = !!::getenv("CC_LOG_DIAGNOSTICS");
   if (TheDriver.CCLogDiagnostics)
     TheDriver.CCLogDiagnosticsFilename = ::getenv("CC_LOG_DIAGNOSTICS_FILE");

   // Handle QA_OVERRIDE_GCC3_OPTIONS and CCC_ADD_ARGS, used for editing a
   // command line behind the scenes.
   if (const char *OverrideStr = ::getenv("QA_OVERRIDE_GCC3_OPTIONS")) {
     // FIXME: Driver shouldn't take extra initial argument.
     ApplyQAOverride(argv, OverrideStr, SavedStrings);
   } else if (const char *Cur = ::getenv("CCC_ADD_ARGS")) {
     // FIXME: Driver shouldn't take extra initial argument.
     std::vector<const char*> ExtraArgs;

     for (;;) {
       const char *Next = strchr(Cur, ',');

       if (Next) {
         ExtraArgs.push_back(SaveStringInSet(SavedStrings,
                                             std::string(Cur, Next)));
         Cur = Next + 1;
       } else {
         if (*Cur != '\0')
           ExtraArgs.push_back(SaveStringInSet(SavedStrings, Cur));
         break;
       }
     }

     argv.insert(&argv[1], ExtraArgs.begin(), ExtraArgs.end());
   }

   llvm::OwningPtr<Compilation> C(TheDriver.BuildCompilation(argv));
   int Res = 0;
   if (C.get())
     Res = TheDriver.ExecuteCompilation(*C);

   // If any timers were active but haven't been destroyed yet, print their
   // results now.  This happens in -disable-free mode.
   llvm::TimerGroup::printAll(llvm::errs());

   llvm::llvm_shutdown();

   return Res;
 }
	//===-- driver.cpp - Clang GCC-Compatible Driver --------------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This is the entry point to the clang driver; it is a thin wrapper
	// for functionality in the Driver clang library.
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Driver/Compilation.h"
	#include "clang/Driver/Driver.h"
	#include "clang/Driver/Option.h"
	#include "clang/Frontend/DiagnosticOptions.h"
	#include "clang/Frontend/TextDiagnosticPrinter.h"

	#include "llvm/ADT/ArrayRef.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/ADT/OwningPtr.h"
	#include "llvm/Config/config.h"
	#include "llvm/Support/ErrorHandling.h"
	#include "llvm/Support/FileSystem.h"
	#include "llvm/Support/ManagedStatic.h"
	#include "llvm/Support/MemoryBuffer.h"
	#include "llvm/Support/PrettyStackTrace.h"
	#include "llvm/Support/Regex.h"
	#include "llvm/Support/Timer.h"
	#include "llvm/Support/raw_ostream.h"
	#include "llvm/Support/Host.h"
	#include "llvm/Support/Path.h"
	#include "llvm/Support/Program.h"
	#include "llvm/Support/Signals.h"
	#include "llvm/Support/system_error.h"
	#include "llvm/Target/TargetRegistry.h"
	#include "llvm/Target/TargetSelect.h"
	#include <cctype>
	using namespace clang;
	using namespace clang::driver;

	llvm::sys::Path GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
	if (!CanonicalPrefixes)
	return llvm::sys::Path(Argv0);

	// This just needs to be some symbol in the binary; C++ doesn't
	// allow taking the address of ::main however.
	void P = (void) (intptr_t) GetExecutablePath;
	return llvm::sys::Path::GetMainExecutable(Argv0, P);
	}

	static const char *SaveStringInSet(std::set<std::string> &SavedStrings,
	llvm::StringRef S) {
	return SavedStrings.insert(S).first->c_str();
	}

	/// ApplyQAOverride - Apply a list of edits to the input argument lists.
	///
	/// The input string is a space separate list of edits to perform,
	/// they are applied in order to the input argument lists. Edits
	/// should be one of the following forms:
	///
	/// '#': Silence information about the changes to the command line arguments.
	///
	/// '^': Add FOO as a new argument at the beginning of the command line.
	///
	/// '+': Add FOO as a new argument at the end of the command line.
	///
	/// 's/XXX/YYY/': Substitute the regular expression XXX with YYY in the command
	/// line.
	///
	/// 'xOPTION': Removes all instances of the literal argument OPTION.
	///
	/// 'XOPTION': Removes all instances of the literal argument OPTION,
	/// and the following argument.
	///
	/// 'Ox': Removes all flags matching 'O' or 'O[sz0-9]' and adds 'Ox'
	/// at the end of the command line.
	///
	/// \param OS - The stream to write edit information to.
	/// \param Args - The vector of command line arguments.
	/// \param Edit - The override command to perform.
	/// \param SavedStrings - Set to use for storing string representations.
	static void ApplyOneQAOverride(llvm::raw_ostream &OS,
	llvm::SmallVectorImpl<const char*> &Args,
	llvm::StringRef Edit,
	std::set<std::string> &SavedStrings) {
	// This does not need to be efficient.

	if (Edit[0] == '^') {
	const char *Str =
	SaveStringInSet(SavedStrings, Edit.substr(1));
	OS << "### Adding argument " << Str << " at beginning\n";
	Args.insert(Args.begin() + 1, Str);
	} else if (Edit[0] == '+') {
	const char *Str =
	SaveStringInSet(SavedStrings, Edit.substr(1));
	OS << "### Adding argument " << Str << " at end\n";
	Args.push_back(Str);
	} else if (Edit[0] == 's' && Edit[1] == '/' && Edit.endswith("/") &&
	Edit.slice(2, Edit.size()-1).find('/') != llvm::StringRef::npos) {
	llvm::StringRef MatchPattern = Edit.substr(2).split('/').first;
	llvm::StringRef ReplPattern = Edit.substr(2).split('/').second;
	ReplPattern = ReplPattern.slice(0, ReplPattern.size()-1);

	for (unsigned i = 1, e = Args.size(); i != e; ++i) {
	std::string Repl = llvm::Regex(MatchPattern).sub(ReplPattern, Args[i]);

	if (Repl != Args[i]) {
	OS << "### Replacing '" << Args[i] << "' with '" << Repl << "'\n";
	Args[i] = SaveStringInSet(SavedStrings, Repl);
	}
	}
	} else if (Edit[0] == 'x' \|\| Edit[0] == 'X') {
	std::string Option = Edit.substr(1, std::string::npos);
	for (unsigned i = 1; i < Args.size();) {
	if (Option == Args[i]) {
	OS << "### Deleting argument " << Args[i] << '\n';
	Args.erase(Args.begin() + i);
	if (Edit[0] == 'X') {
	if (i < Args.size()) {
	OS << "### Deleting argument " << Args[i] << '\n';
	Args.erase(Args.begin() + i);
	} else
	OS << "### Invalid X edit, end of command line!\n";
	}
	} else
	++i;
	}
	} else if (Edit[0] == 'O') {
	for (unsigned i = 1; i < Args.size();) {
	const char *A = Args[i];
	if (A[0] == '-' && A[1] == 'O' &&
	(A[2] == '\0' \|\|
	(A[3] == '\0' && (A[2] == 's' \|\| A[2] == 'z' \|\|
	('0' <= A[2] && A[2] <= '9'))))) {
	OS << "### Deleting argument " << Args[i] << '\n';
	Args.erase(Args.begin() + i);
	} else
	++i;
	}
	OS << "### Adding argument " << Edit << " at end\n";
	Args.push_back(SaveStringInSet(SavedStrings, '-' + Edit.str()));
	} else {
	OS << "### Unrecognized edit: " << Edit << "\n";
	}
	}

	/// ApplyQAOverride - Apply a comma separate list of edits to the
	/// input argument lists. See ApplyOneQAOverride.
	static void ApplyQAOverride(llvm::SmallVectorImpl<const char*> &Args,
	const char *OverrideStr,
	std::set<std::string> &SavedStrings) {
	llvm::raw_ostream *OS = &llvm::errs();

	if (OverrideStr[0] == '#') {
	++OverrideStr;
	OS = &llvm::nulls();
	}

	*OS << "### QA_OVERRIDE_GCC3_OPTIONS: " << OverrideStr << "\n";

	// This does not need to be efficient.

	const char *S = OverrideStr;
	while (*S) {
	const char *End = ::strchr(S, ' ');
	if (!End)
	End = S + strlen(S);
	if (End != S)
	ApplyOneQAOverride(*OS, Args, std::string(S, End), SavedStrings);
	S = End;
	if (*S != '\0')
	++S;
	}
	}

	extern int cc1_main(const char ArgBegin, const char ArgEnd,
	const char Argv0, void MainAddr);
	extern int cc1as_main(const char ArgBegin, const char ArgEnd,
	const char Argv0, void MainAddr);

	static void ExpandArgsFromBuf(const char *Arg,
	llvm::SmallVectorImpl<const char*> &ArgVector,
	std::set<std::string> &SavedStrings) {
	const char *FName = Arg + 1;
	llvm::OwningPtr<llvm::MemoryBuffer> MemBuf;
	if (llvm::MemoryBuffer::getFile(FName, MemBuf)) {
	ArgVector.push_back(SaveStringInSet(SavedStrings, Arg));
	return;
	}

	const char *Buf = MemBuf->getBufferStart();
	char InQuote = ' ';
	std::string CurArg;

	for (const char *P = Buf; ; ++P) {
	if (P == '\0' \|\| (isspace(P) && InQuote == ' ')) {
	if (!CurArg.empty()) {

	if (CurArg[0] != '@') {
	ArgVector.push_back(SaveStringInSet(SavedStrings, CurArg));
	} else {
	ExpandArgsFromBuf(CurArg.c_str(), ArgVector, SavedStrings);
	}

	CurArg = "";
	}
	if (*P == '\0')
	break;
	else
	continue;
	}

	if (isspace(*P)) {
	if (InQuote != ' ')
	CurArg.push_back(*P);
	continue;
	}

	if (P == '"' \|\| P == '\'') {
	if (InQuote == *P)
	InQuote = ' ';
	else if (InQuote == ' ')
	InQuote = *P;
	else
	CurArg.push_back(*P);
	continue;
	}

	if (*P == '\\') {
	++P;
	if (*P != '\0')
	CurArg.push_back(*P);
	continue;
	}
	CurArg.push_back(*P);
	}
	}

	static void ExpandArgv(int argc, const char **argv,
	llvm::SmallVectorImpl<const char*> &ArgVector,
	std::set<std::string> &SavedStrings) {
	for (int i = 0; i < argc; ++i) {
	const char *Arg = argv[i];
	if (Arg[0] != '@') {
	ArgVector.push_back(SaveStringInSet(SavedStrings, std::string(Arg)));
	continue;
	}

	ExpandArgsFromBuf(Arg, ArgVector, SavedStrings);
	}
	}

	static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
	std::set<std::string> &SavedStrings,
	Driver &TheDriver)
	{
	// Try to infer frontend type and default target from the program name.

	// suffixes[] contains the list of known driver suffixes.
	// Suffixes are compared against the program name in order.
	// If there is a match, the frontend type is updated as necessary (CPP/C++).
	// If there is no match, a second round is done after stripping the last
	// hyphen and everything following it. This allows using something like
	// "clang++-2.9".

	// If there is a match in either the first or second round,
	// the function tries to identify a target as prefix. E.g.
	// "x86_64-linux-clang" as interpreted as suffix "clang" with
	// target prefix "x86_64-linux". If such a target prefix is found,
	// is gets added via -ccc-host-triple as implicit first argument.
	static const struct {
	const char *Suffix;
	bool IsCXX;
	bool IsCPP;
	} suffixes [] = {
	{ "clang", false, false },
	{ "clang++", true, false },
	{ "clang-c++", true, false },
	{ "clang-cc", false, false },
	{ "clang-cpp", false, true },
	{ "clang-g++", true, false },
	{ "clang-gcc", false, false },
	{ "cc", false, false },
	{ "cpp", false, true },
	{ "++", true, false },
	};
	std::string ProgName(llvm::sys::path::stem(ArgVector[0]));
	llvm::StringRef ProgNameRef(ProgName);
	llvm::StringRef Prefix;

	for (int Components = 2; Components; --Components) {
	bool FoundMatch = false;
	size_t i;

	for (i = 0; i < sizeof(suffixes) / sizeof(suffixes[0]); ++i) {
	if (ProgNameRef.endswith(suffixes[i].Suffix)) {
	FoundMatch = true;
	if (suffixes[i].IsCXX)
	TheDriver.CCCIsCXX = true;
	if (suffixes[i].IsCPP)
	TheDriver.CCCIsCPP = true;
	break;
	}
	}

	if (FoundMatch) {
	llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-',
	ProgNameRef.size() - strlen(suffixes[i].Suffix));
	if (LastComponent != llvm::StringRef::npos)
	Prefix = ProgNameRef.slice(0, LastComponent);
	break;
	}

	llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-');
	if (LastComponent == llvm::StringRef::npos)
	break;
	ProgNameRef = ProgNameRef.slice(0, LastComponent);
	}

	if (Prefix.empty())
	return;

	std::string IgnoredError;
	if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
	llvm::SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
	if (it != ArgVector.end())
	++it;
	ArgVector.insert(it, SaveStringInSet(SavedStrings, Prefix));
	ArgVector.insert(it,
	SaveStringInSet(SavedStrings, std::string("-ccc-host-triple")));
	}
	}

	int main(int argc_, const char **argv_) {
	llvm::sys::PrintStackTraceOnErrorSignal();
	llvm::PrettyStackTraceProgram X(argc_, argv_);

	std::set<std::string> SavedStrings;
	llvm::SmallVector<const char*, 256> argv;

	ExpandArgv(argc_, argv_, argv, SavedStrings);

	// Handle -cc1 integrated tools.
	if (argv.size() > 1 && llvm::StringRef(argv[1]).startswith("-cc1")) {
	llvm::StringRef Tool = argv[1] + 4;

	if (Tool == "")
	return cc1_main(argv.data()+2, argv.data()+argv.size(), argv[0],
	(void*) (intptr_t) GetExecutablePath);
	if (Tool == "as")
	return cc1as_main(argv.data()+2, argv.data()+argv.size(), argv[0],
	(void*) (intptr_t) GetExecutablePath);

	// Reject unknown tools.
	llvm::errs() << "error: unknown integrated tool '" << Tool << "'\n";
	return 1;
	}

	bool CanonicalPrefixes = true;
	for (int i = 1, size = argv.size(); i < size; ++i) {
	if (llvm::StringRef(argv[i]) == "-no-canonical-prefixes") {
	CanonicalPrefixes = false;
	break;
	}
	}

	llvm::sys::Path Path = GetExecutablePath(argv[0], CanonicalPrefixes);

	TextDiagnosticPrinter *DiagClient
	= new TextDiagnosticPrinter(llvm::errs(), DiagnosticOptions());
	DiagClient->setPrefix(llvm::sys::path::stem(Path.str()));
	llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
	Diagnostic Diags(DiagID, DiagClient);

	#ifdef CLANG_IS_PRODUCTION
	const bool IsProduction = true;
	# ifdef CLANGXX_IS_PRODUCTION
	const bool CXXIsProduction = true;
	# else
	const bool CXXIsProduction = false;
	# endif
	#else
	const bool IsProduction = false;
	const bool CXXIsProduction = false;
	#endif
	Driver TheDriver(Path.str(), llvm::sys::getHostTriple(),
	"a.out", IsProduction, CXXIsProduction,
	Diags);

	// Attempt to find the original path used to invoke the driver, to determine
	// the installed path. We do this manually, because we want to support that
	// path being a symlink.
	{
	llvm::SmallString<128> InstalledPath(argv[0]);

	// Do a PATH lookup, if there are no directory components.
	if (llvm::sys::path::filename(InstalledPath) == InstalledPath) {
	llvm::sys::Path Tmp = llvm::sys::Program::FindProgramByName(
	llvm::sys::path::filename(InstalledPath.str()));
	if (!Tmp.empty())
	InstalledPath = Tmp.str();
	}
	llvm::sys::fs::make_absolute(InstalledPath);
	InstalledPath = llvm::sys::path::parent_path(InstalledPath);
	bool exists;
	if (!llvm::sys::fs::exists(InstalledPath.str(), exists) && exists)
	TheDriver.setInstalledDir(InstalledPath);
	}

	llvm::InitializeAllTargets();
	ParseProgName(argv, SavedStrings, TheDriver);

	// Handle CC_PRINT_OPTIONS and CC_PRINT_OPTIONS_FILE.
	TheDriver.CCPrintOptions = !!::getenv("CC_PRINT_OPTIONS");
	if (TheDriver.CCPrintOptions)
	TheDriver.CCPrintOptionsFilename = ::getenv("CC_PRINT_OPTIONS_FILE");

	// Handle CC_PRINT_HEADERS and CC_PRINT_HEADERS_FILE.
	TheDriver.CCPrintHeaders = !!::getenv("CC_PRINT_HEADERS");
	if (TheDriver.CCPrintHeaders)
	TheDriver.CCPrintHeadersFilename = ::getenv("CC_PRINT_HEADERS_FILE");

	// Handle CC_LOG_DIAGNOSTICS and CC_LOG_DIAGNOSTICS_FILE.
	TheDriver.CCLogDiagnostics = !!::getenv("CC_LOG_DIAGNOSTICS");
	if (TheDriver.CCLogDiagnostics)
	TheDriver.CCLogDiagnosticsFilename = ::getenv("CC_LOG_DIAGNOSTICS_FILE");

	// Handle QA_OVERRIDE_GCC3_OPTIONS and CCC_ADD_ARGS, used for editing a
	// command line behind the scenes.
	if (const char *OverrideStr = ::getenv("QA_OVERRIDE_GCC3_OPTIONS")) {
	// FIXME: Driver shouldn't take extra initial argument.
	ApplyQAOverride(argv, OverrideStr, SavedStrings);
	} else if (const char *Cur = ::getenv("CCC_ADD_ARGS")) {
	// FIXME: Driver shouldn't take extra initial argument.
	std::vector<const char*> ExtraArgs;

	for (;;) {
	const char *Next = strchr(Cur, ',');

	if (Next) {
	ExtraArgs.push_back(SaveStringInSet(SavedStrings,
	std::string(Cur, Next)));
	Cur = Next + 1;
	} else {
	if (*Cur != '\0')
	ExtraArgs.push_back(SaveStringInSet(SavedStrings, Cur));
	break;
	}
	}

	argv.insert(&argv[1], ExtraArgs.begin(), ExtraArgs.end());
	}

	llvm::OwningPtr<Compilation> C(TheDriver.BuildCompilation(argv));
	int Res = 0;
	if (C.get())
	Res = TheDriver.ExecuteCompilation(*C);

	// If any timers were active but haven't been destroyed yet, print their
	// results now. This happens in -disable-free mode.
	llvm::TimerGroup::printAll(llvm::errs());

	llvm::llvm_shutdown();

	return Res;
	}