Implement -working-directory.

When -working-directory is passed in command line, file paths are resolved relative to the specified directory.
This helps both when using libclang (where we can't require the user to actually change the working directory)
and to help reproduce test cases when the reproduction work comes along.

--FileSystemOptions is introduced which controls how file system operations are performed (currently it just contains
 the working directory value if set).
--FileSystemOptions are passed around to various interfaces that perform file operations.
--Opening & reading the content of files should be done only through FileManager. This is useful in general since
 file operations will be abstracted in the future for the reproduction mechanism.

FileSystemOptions is independent of FileManager so that we can have multiple translation units sharing the same
FileManager but with different FileSystemOptions.

Addresses rdar://8583824.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118203 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ASTMerge.cpp b/lib/Frontend/ASTMerge.cpp
index b46212f..f270846 100644
--- a/lib/Frontend/ASTMerge.cpp
+++ b/lib/Frontend/ASTMerge.cpp
@@ -40,7 +40,8 @@
                                        &CI.getASTContext());
   llvm::IntrusiveRefCntPtr<Diagnostic> Diags(&CI.getDiagnostics());
   for (unsigned I = 0, N = ASTFiles.size(); I != N; ++I) {
-    ASTUnit *Unit = ASTUnit::LoadFromASTFile(ASTFiles[I], Diags, false);
+    ASTUnit *Unit = ASTUnit::LoadFromASTFile(ASTFiles[I], Diags,
+                                             CI.getFileSystemOpts(), false);
     if (!Unit)
       continue;
 
@@ -53,8 +54,10 @@
     ASTImporter Importer(CI.getDiagnostics(),
                          CI.getASTContext(), 
                          CI.getFileManager(),
+                         CI.getFileSystemOpts(),
                          Unit->getASTContext(), 
-                         Unit->getFileManager());
+                         Unit->getFileManager(),
+                         Unit->getFileSystemOpts());
 
     TranslationUnitDecl *TU = Unit->getASTContext().getTranslationUnitDecl();
     for (DeclContext::decl_iterator D = TU->decls_begin(), 
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index b07ed12..bbee11b 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -449,8 +449,17 @@
   return static_cast<ASTReader *>(Ctx->getExternalSource())->getFileName();
 }
 
+llvm::MemoryBuffer *ASTUnit::getBufferForFile(llvm::StringRef Filename,
+                                              std::string *ErrorStr,
+                                              int64_t FileSize,
+                                              struct stat *FileInfo) {
+  return FileMgr->getBufferForFile(Filename, FileSystemOpts,
+                                   ErrorStr, FileSize, FileInfo);
+}
+
 ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
                                   llvm::IntrusiveRefCntPtr<Diagnostic> Diags,
+                                  const FileSystemOptions &FileSystemOpts,
                                   bool OnlyLocalDecls,
                                   RemappedFile *RemappedFiles,
                                   unsigned NumRemappedFiles,
@@ -467,9 +476,13 @@
   AST->CaptureDiagnostics = CaptureDiagnostics;
   AST->OnlyLocalDecls = OnlyLocalDecls;
   AST->Diagnostics = Diags;
+  AST->FileSystemOpts = FileSystemOpts;
   AST->FileMgr.reset(new FileManager);
-  AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics()));
-  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager()));
+  AST->SourceMgr.reset(new SourceManager(AST->getDiagnostics(),
+                                         AST->getFileManager(),
+                                         AST->getFileSystemOpts()));
+  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager(),
+                                         AST->getFileSystemOpts()));
   
   // If requested, capture diagnostics in the ASTUnit.
   CaptureDroppedDiagnostics Capture(CaptureDiagnostics, AST->getDiagnostics(),
@@ -480,7 +493,8 @@
     const FileEntry *FromFile
       = AST->getFileManager().getVirtualFile(RemappedFiles[I].first,
                                     RemappedFiles[I].second->getBufferSize(),
-                                             0);
+                                             0,
+                                             AST->getFileSystemOpts());
     if (!FromFile) {
       AST->getDiagnostics().Report(diag::err_fe_remap_missing_from_file)
         << RemappedFiles[I].first;
@@ -505,7 +519,7 @@
   llvm::OwningPtr<ASTReader> Reader;
 
   Reader.reset(new ASTReader(AST->getSourceManager(), AST->getFileManager(),
-                             AST->getDiagnostics()));
+                             AST->getFileSystemOpts(), AST->getDiagnostics()));
   Reader->setListener(new ASTInfoCollector(LangInfo, HeaderInfo, TargetTriple,
                                            Predefines, Counter));
 
@@ -732,7 +746,8 @@
   // Configure the various subsystems.
   // FIXME: Should we retain the previous file manager?
   FileMgr.reset(new FileManager);
-  SourceMgr.reset(new SourceManager(getDiagnostics()));
+  FileSystemOpts = Clang.getFileSystemOpts();
+  SourceMgr.reset(new SourceManager(getDiagnostics(), *FileMgr, FileSystemOpts));
   TheSema.reset();
   Ctx.reset();
   PP.reset();
@@ -908,7 +923,7 @@
             CreatedBuffer = false;
           }
           
-          Buffer = llvm::MemoryBuffer::getFile(M->second);
+          Buffer = getBufferForFile(M->second);
           if (!Buffer)
             return std::make_pair((llvm::MemoryBuffer*)0, 
                                   std::make_pair(0, true));
@@ -941,7 +956,7 @@
   
   // If the main source file was not remapped, load it now.
   if (!Buffer) {
-    Buffer = llvm::MemoryBuffer::getFile(FrontendOpts.Inputs[0].second);
+    Buffer = getBufferForFile(FrontendOpts.Inputs[0].second);
     if (!Buffer)
       return std::make_pair((llvm::MemoryBuffer*)0, std::make_pair(0, true));    
     
@@ -1240,7 +1255,9 @@
   Clang.setFileManager(new FileManager);
   
   // Create the source manager.
-  Clang.setSourceManager(new SourceManager(getDiagnostics()));
+  Clang.setSourceManager(new SourceManager(getDiagnostics(),
+                                           Clang.getFileManager(),
+                                           Clang.getFileSystemOpts()));
   
   llvm::OwningPtr<PrecompilePreambleAction> Act;
   Act.reset(new PrecompilePreambleAction(*this));
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 95d417f..c5e5d7f 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -148,8 +148,9 @@
 
 // Source Manager
 
-void CompilerInstance::createSourceManager() {
-  SourceMgr.reset(new SourceManager(getDiagnostics()));
+void CompilerInstance::createSourceManager(FileManager &FileMgr,
+                                           const FileSystemOptions &FSOpts) {
+  SourceMgr.reset(new SourceManager(getDiagnostics(), FileMgr, FSOpts));
 }
 
 // Preprocessor
@@ -158,8 +159,8 @@
   PP.reset(createPreprocessor(getDiagnostics(), getLangOpts(),
                               getPreprocessorOpts(), getHeaderSearchOpts(),
                               getDependencyOutputOpts(), getTarget(),
-                              getFrontendOpts(), getSourceManager(),
-                              getFileManager()));
+                              getFrontendOpts(), getFileSystemOpts(),
+                              getSourceManager(), getFileManager()));
 }
 
 Preprocessor *
@@ -170,15 +171,16 @@
                                      const DependencyOutputOptions &DepOpts,
                                      const TargetInfo &Target,
                                      const FrontendOptions &FEOpts,
+                                     const FileSystemOptions &FSOpts,
                                      SourceManager &SourceMgr,
                                      FileManager &FileMgr) {
   // Create a PTH manager if we are using some form of a token cache.
   PTHManager *PTHMgr = 0;
   if (!PPOpts.TokenCache.empty())
-    PTHMgr = PTHManager::Create(PPOpts.TokenCache, Diags);
+    PTHMgr = PTHManager::Create(PPOpts.TokenCache, FileMgr, FSOpts, Diags);
 
   // Create the Preprocessor.
-  HeaderSearch *HeaderInfo = new HeaderSearch(FileMgr);
+  HeaderSearch *HeaderInfo = new HeaderSearch(FileMgr, FSOpts);
   Preprocessor *PP = new Preprocessor(Diags, LangInfo, Target,
                                       SourceMgr, *HeaderInfo, PTHMgr,
                                       /*OwnsHeaderSearch=*/true);
@@ -194,7 +196,7 @@
   if (PPOpts.DetailedRecord)
     PP->createPreprocessingRecord();
   
-  InitializePreprocessor(*PP, PPOpts, HSOpts, FEOpts);
+  InitializePreprocessor(*PP, FSOpts, PPOpts, HSOpts, FEOpts);
 
   // Handle generating dependencies, if requested.
   if (!DepOpts.OutputFile.empty())
@@ -271,7 +273,8 @@
                                  unsigned Column) {
   // Tell the source manager to chop off the given file at a specific
   // line and column.
-  const FileEntry *Entry = PP.getFileManager().getFile(Filename);
+  const FileEntry *Entry = PP.getFileManager().getFile(Filename,
+                                                       PP.getFileSystemOpts());
   if (!Entry) {
     PP.getDiagnostics().Report(diag::err_fe_invalid_code_complete_file)
       << Filename;
@@ -352,7 +355,11 @@
         TempPath.eraseFromDisk();
       else {
         std::string Error;
-        if (TempPath.renamePathOnDisk(llvm::sys::Path(it->Filename), &Error)) {
+        llvm::sys::Path NewOutFile(it->Filename);
+        // If '-working-directory' was passed, the output filename should be
+        // relative to that.
+        FileManager::FixupRelativePath(NewOutFile, getFileSystemOpts());
+        if (TempPath.renamePathOnDisk(NewOutFile, &Error)) {
           getDiagnostics().Report(diag::err_fe_unable_to_rename_temp)
             << it->TempFilename << it->Filename << Error;
           TempPath.eraseFromDisk();
@@ -457,17 +464,19 @@
 
 bool CompilerInstance::InitializeSourceManager(llvm::StringRef InputFile) {
   return InitializeSourceManager(InputFile, getDiagnostics(), getFileManager(),
+                                 getFileSystemOpts(),
                                  getSourceManager(), getFrontendOpts());
 }
 
 bool CompilerInstance::InitializeSourceManager(llvm::StringRef InputFile,
                                                Diagnostic &Diags,
                                                FileManager &FileMgr,
+                                               const FileSystemOptions &FSOpts,
                                                SourceManager &SourceMgr,
                                                const FrontendOptions &Opts) {
   // Figure out where to get and map in the main file.
   if (InputFile != "-") {
-    const FileEntry *File = FileMgr.getFile(InputFile);
+    const FileEntry *File = FileMgr.getFile(InputFile, FSOpts);
     if (!File) {
       Diags.Report(diag::err_fe_error_reading) << InputFile;
       return false;
@@ -480,7 +489,8 @@
       return false;
     }
     const FileEntry *File = FileMgr.getVirtualFile(SB->getBufferIdentifier(),
-                                                   SB->getBufferSize(), 0);
+                                                   SB->getBufferSize(), 0,
+                                                   FSOpts);
     SourceMgr.createMainFileID(File);
     SourceMgr.overrideFileContents(File, SB);
   }
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 561555a..b20520b 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -10,6 +10,7 @@
 #include "clang/Frontend/CompilerInvocation.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/Version.h"
+#include "clang/Basic/FileManager.h"
 #include "clang/Driver/Arg.h"
 #include "clang/Driver/ArgList.h"
 #include "clang/Driver/CC1Options.h"
@@ -351,6 +352,14 @@
   return 0;
 }
 
+static void FileSystemOptsToArgs(const FileSystemOptions &Opts,
+                                 std::vector<std::string> &Res) {
+  if (!Opts.WorkingDir.empty()) {
+    Res.push_back("-working-directory");
+    Res.push_back(Opts.WorkingDir);
+  }
+}
+
 static void FrontendOptsToArgs(const FrontendOptions &Opts,
                                std::vector<std::string> &Res) {
   if (Opts.DisableFree)
@@ -743,6 +752,7 @@
   CodeGenOptsToArgs(getCodeGenOpts(), Res);
   DependencyOutputOptsToArgs(getDependencyOutputOpts(), Res);
   DiagnosticOptsToArgs(getDiagnosticOpts(), Res);
+  FileSystemOptsToArgs(getFileSystemOpts(), Res);
   FrontendOptsToArgs(getFrontendOpts(), Res);
   HeaderSearchOptsToArgs(getHeaderSearchOpts(), Res);
   LangOptsToArgs(getLangOpts(), Res);
@@ -979,6 +989,10 @@
   Opts.Warnings = Args.getAllArgValues(OPT_W);
 }
 
+static void ParseFileSystemArgs(FileSystemOptions &Opts, ArgList &Args) {
+  Opts.WorkingDir = Args.getLastArgValue(OPT_working_directory);
+}
+
 static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
                                    Diagnostic &Diags) {
   using namespace cc1options;
@@ -1402,6 +1416,8 @@
 }
 
 static void ParsePreprocessorArgs(PreprocessorOptions &Opts, ArgList &Args,
+                                  FileManager &FileMgr,
+                                  const FileSystemOptions &FSOpts,
                                   Diagnostic &Diags) {
   using namespace cc1options;
   Opts.ImplicitPCHInclude = Args.getLastArgValue(OPT_include_pch);
@@ -1456,7 +1472,8 @@
     // PCH is handled specially, we need to extra the original include path.
     if (A->getOption().matches(OPT_include_pch)) {
       std::string OriginalFile =
-        ASTReader::getOriginalSourceFile(A->getValue(Args), Diags);
+        ASTReader::getOriginalSourceFile(A->getValue(Args), FileMgr, FSOpts,
+                                         Diags);
       if (OriginalFile.empty())
         continue;
 
@@ -1535,11 +1552,18 @@
   ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, Diags);
   ParseDependencyOutputArgs(Res.getDependencyOutputOpts(), *Args);
   ParseDiagnosticArgs(Res.getDiagnosticOpts(), *Args, Diags);
+  ParseFileSystemArgs(Res.getFileSystemOpts(), *Args);
   InputKind DashX = ParseFrontendArgs(Res.getFrontendOpts(), *Args, Diags);
   ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), *Args);
   if (DashX != IK_AST && DashX != IK_LLVM_IR)
     ParseLangArgs(Res.getLangOpts(), *Args, DashX, Diags);
-  ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args, Diags);
+  // FIXME: ParsePreprocessorArgs uses the FileManager to read the contents of
+  // PCH file and find the original header name. Remove the need to do that in
+  // ParsePreprocessorArgs and remove the FileManager & FileSystemOptions
+  // parameters from the function and the "FileManager.h" #include.
+  FileManager FileMgr;
+  ParsePreprocessorArgs(Res.getPreprocessorOpts(), *Args,
+                        FileMgr, Res.getFileSystemOpts(), Diags);
   ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args);
   ParseTargetArgs(Res.getTargetOpts(), *Args);
 }
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 48f115f..cfa0b6d 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -103,7 +103,8 @@
 
     llvm::IntrusiveRefCntPtr<Diagnostic> Diags(&CI.getDiagnostics());
     std::string Error;
-    ASTUnit *AST = ASTUnit::LoadFromASTFile(Filename, Diags);
+    ASTUnit *AST = ASTUnit::LoadFromASTFile(Filename, Diags,
+                                            CI.getFileSystemOpts());
     if (!AST)
       goto failure;
 
@@ -132,7 +133,7 @@
   if (!CI.hasFileManager())
     CI.createFileManager();
   if (!CI.hasSourceManager())
-    CI.createSourceManager();
+    CI.createSourceManager(CI.getFileManager(), CI.getFileSystemOpts());
 
   // IR files bypass the rest of initialization.
   if (InputKind == IK_LLVM_IR) {
diff --git a/lib/Frontend/FrontendActions.cpp b/lib/Frontend/FrontendActions.cpp
index 5bc6506..9ef1ca6 100644
--- a/lib/Frontend/FrontendActions.cpp
+++ b/lib/Frontend/FrontendActions.cpp
@@ -207,7 +207,10 @@
     return;
   }
   
-  llvm::MemoryBuffer *Buffer = llvm::MemoryBuffer::getFile(getCurrentFile());
+  CompilerInstance &CI = getCompilerInstance();
+  llvm::MemoryBuffer *Buffer
+      = CI.getFileManager().getBufferForFile(getCurrentFile(),
+                                             CI.getFileSystemOpts());
   if (Buffer) {
     unsigned Preamble = Lexer::ComputePreamble(Buffer).first;
     llvm::outs().write(Buffer->getBufferStart(), Preamble);
diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index 97157b3..e47381e 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -99,6 +99,7 @@
                                bool IgnoreSysRoot) {
   assert(!Path.isTriviallyEmpty() && "can't handle empty path here");
   FileManager &FM = Headers.getFileMgr();
+  const FileSystemOptions &FSOpts = Headers.getFileSystemOpts();
 
   // Compute the actual path, taking into consideration -isysroot.
   llvm::SmallString<256> MappedPathStr;
@@ -125,7 +126,7 @@
 
 
   // If the directory exists, add it.
-  if (const DirectoryEntry *DE = FM.getDirectory(MappedPath.str())) {
+  if (const DirectoryEntry *DE = FM.getDirectory(MappedPath.str(), FSOpts)) {
     IncludeGroup[Group].push_back(DirectoryLookup(DE, Type, isUserSupplied,
                                                   isFramework));
     return;
@@ -134,7 +135,7 @@
   // Check to see if this is an apple-style headermap (which are not allowed to
   // be frameworks).
   if (!isFramework) {
-    if (const FileEntry *FE = FM.getFile(MappedPath.str())) {
+    if (const FileEntry *FE = FM.getFile(MappedPath.str(), FSOpts)) {
       if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
         // It is a headermap, add it to the search path.
         IncludeGroup[Group].push_back(DirectoryLookup(HM, Type,isUserSupplied));
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 181f671..7275733 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -478,6 +478,7 @@
 static void InitializeFileRemapping(Diagnostic &Diags,
                                     SourceManager &SourceMgr,
                                     FileManager &FileMgr,
+                                    const FileSystemOptions &FSOpts,
                                     const PreprocessorOptions &InitOpts) {
   // Remap files in the source manager (with buffers).
   for (PreprocessorOptions::const_remapped_file_buffer_iterator
@@ -488,7 +489,7 @@
     // Create the file entry for the file that we're mapping from.
     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
                                                 Remap->second->getBufferSize(),
-                                                       0);
+                                                       0, FSOpts);
     if (!FromFile) {
       Diags.Report(diag::err_fe_remap_missing_from_file)
         << Remap->first;
@@ -510,7 +511,7 @@
        Remap != RemapEnd;
        ++Remap) {
     // Find the file that we're mapping to.
-    const FileEntry *ToFile = FileMgr.getFile(Remap->second);
+    const FileEntry *ToFile = FileMgr.getFile(Remap->second, FSOpts);
     if (!ToFile) {
       Diags.Report(diag::err_fe_remap_missing_to_file)
       << Remap->first << Remap->second;
@@ -520,7 +521,7 @@
     // Create the file entry for the file that we're mapping from.
     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
                                                        ToFile->getSize(),
-                                                       0);
+                                                       0, FSOpts);
     if (!FromFile) {
       Diags.Report(diag::err_fe_remap_missing_from_file)
       << Remap->first;
@@ -530,7 +531,7 @@
     // Load the contents of the file we're mapping to.
     std::string ErrorStr;
     const llvm::MemoryBuffer *Buffer
-    = llvm::MemoryBuffer::getFile(ToFile->getName(), &ErrorStr);
+    = FileMgr.getBufferForFile(ToFile->getName(), FSOpts, &ErrorStr);
     if (!Buffer) {
       Diags.Report(diag::err_fe_error_opening)
         << Remap->second << ErrorStr;
@@ -547,6 +548,7 @@
 /// environment ready to process a single file. This returns true on error.
 ///
 void clang::InitializePreprocessor(Preprocessor &PP,
+                                   const FileSystemOptions &FSOpts,
                                    const PreprocessorOptions &InitOpts,
                                    const HeaderSearchOptions &HSOpts,
                                    const FrontendOptions &FEOpts) {
@@ -556,7 +558,7 @@
   MacroBuilder Builder(Predefines);
 
   InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
-                          PP.getFileManager(), InitOpts);
+                          PP.getFileManager(), FSOpts, InitOpts);
 
   // Emit line markers for various builtin sections of the file.  We don't do
   // this in asm preprocessor mode, because "# 4" is not a line marker directive