[Driver] Fix -working-directory issues

Currently the `-working-directory` option does not actually impact the working
directory for all of the clang driver, it only impacts how files are looked up
to make sure they exist.  This means that that clang passes the wrong paths
to -fdebug-compilation-dir and -coverage-notes-file.

This patch fixes that by changing all the places in the driver where we convert
to absolute paths to use the VFS, and then calling setCurrentWorkingDirectory on
the VFS.  This also changes the default VFS for `Driver` to use a virtualized
working directory, instead of changing the process's working directory.

Differential Revision: https://reviews.llvm.org/D62271

llvm-svn: 361885

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -91,6 +91,8 @@ def err_no_external_assembler : Error<
   "there is no external assembler that can be used on this platform">;
 def err_drv_unable_to_remove_file : Error<
   "unable to remove file: %0">;
+def err_drv_unable_to_set_working_directory : Error <
+  "unable to set working directory: %0">;
 def err_drv_command_failure : Error<
   "unable to execute command: %0">;
 def err_drv_invalid_darwin_version : Error<

clang/lib/Driver/Driver.cpp

@@ -133,7 +133,7 @@ Driver::Driver(StringRef ClangExecutable, StringRef TargetTriple,
 
   // Provide a sane fallback if no VFS is specified.
   if (!this->VFS)
-    this->VFS = llvm::vfs::getRealFileSystem();
+    this->VFS = llvm::vfs::createPhysicalFileSystem().release();
 
   Name = llvm::sys::path::filename(ClangExecutable);
   Dir = llvm::sys::path::parent_path(ClangExecutable);
@@ -1005,6 +1005,11 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
     }
   }
 
+  // Check for working directory option before accessing any files
+  if (Arg *WD = Args.getLastArg(options::OPT_working_directory))
+    if (std::error_code EC = VFS->setCurrentWorkingDirectory(WD->getValue()))
+      Diag(diag::err_drv_unable_to_set_working_directory) << WD->getValue();
+
   // FIXME: This stuff needs to go into the Compilation, not the driver.
   bool CCCPrintPhases;
 
@@ -1984,20 +1989,11 @@ bool Driver::DiagnoseInputExistence(const DerivedArgList &Args, StringRef Value,
   if (Value == "-")
     return true;
 
-  SmallString<64> Path(Value);
-  if (Arg *WorkDir = Args.getLastArg(options::OPT_working_directory)) {
-    if (!llvm::sys::path::is_absolute(Path)) {
-      SmallString<64> Directory(WorkDir->getValue());
-      llvm::sys::path::append(Directory, Value);
-      Path.assign(Directory);
-    }
-  }
-
-  if (getVFS().exists(Path))
+  if (getVFS().exists(Value))
     return true;
 
   if (IsCLMode()) {
-    if (!llvm::sys::path::is_absolute(Twine(Path)) &&
+    if (!llvm::sys::path::is_absolute(Twine(Value)) &&
         llvm::sys::Process::FindInEnvPath("LIB", Value))
       return true;
 
@@ -2023,12 +2019,12 @@ bool Driver::DiagnoseInputExistence(const DerivedArgList &Args, StringRef Value,
     if (getOpts().findNearest(Value, Nearest, IncludedFlagsBitmask,
                               ExcludedFlagsBitmask) <= 1) {
       Diag(clang::diag::err_drv_no_such_file_with_suggestion)
-          << Path << Nearest;
+          << Value << Nearest;
       return false;
     }
   }
 
-  Diag(clang::diag::err_drv_no_such_file) << Path;
+  Diag(clang::diag::err_drv_no_such_file) << Value;
   return false;
 }
 

clang/lib/Driver/ToolChains/Clang.cpp

@@ -616,11 +616,11 @@ static bool shouldUseLeafFramePointer(const ArgList &Args,
 }
 
 /// Add a CC1 option to specify the debug compilation directory.
-static void addDebugCompDirArg(const ArgList &Args, ArgStringList &CmdArgs) {
-  SmallString<128> cwd;
-  if (!llvm::sys::fs::current_path(cwd)) {
+static void addDebugCompDirArg(const ArgList &Args, ArgStringList &CmdArgs,
+                               const llvm::vfs::FileSystem &VFS) {
+  if (llvm::ErrorOr<std::string> CWD = VFS.getCurrentWorkingDirectory()) {
     CmdArgs.push_back("-fdebug-compilation-dir");
-    CmdArgs.push_back(Args.MakeArgString(cwd));
+    CmdArgs.push_back(Args.MakeArgString(*CWD));
   }
 }
 
@@ -885,13 +885,8 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
       else
         OutputFilename = llvm::sys::path::filename(Output.getBaseInput());
       SmallString<128> CoverageFilename = OutputFilename;
-      if (llvm::sys::path::is_relative(CoverageFilename)) {
-        SmallString<128> Pwd;
-        if (!llvm::sys::fs::current_path(Pwd)) {
-          llvm::sys::path::append(Pwd, CoverageFilename);
-          CoverageFilename.swap(Pwd);
-        }
-      }
+      if (llvm::sys::path::is_relative(CoverageFilename))
+        (void)D.getVFS().makeAbsolute(CoverageFilename);
       llvm::sys::path::replace_extension(CoverageFilename, "gcno");
       CmdArgs.push_back(Args.MakeArgString(CoverageFilename));
 
@@ -4354,7 +4349,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-fno-autolink");
 
   // Add in -fdebug-compilation-dir if necessary.
-  addDebugCompDirArg(Args, CmdArgs);
+  addDebugCompDirArg(Args, CmdArgs, D.getVFS());
 
   addDebugPrefixMapArg(D, Args, CmdArgs);
 
@@ -6065,7 +6060,7 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
     DebugInfoKind = (WantDebug ? codegenoptions::LimitedDebugInfo
                                : codegenoptions::NoDebugInfo);
     // Add the -fdebug-compilation-dir flag if needed.
-    addDebugCompDirArg(Args, CmdArgs);
+    addDebugCompDirArg(Args, CmdArgs, C.getDriver().getVFS());
 
     addDebugPrefixMapArg(getToolChain().getDriver(), Args, CmdArgs);
 

clang/test/Driver/working-directory.c

@@ -1,3 +1,11 @@
 // RUN: %clang -### -working-directory /no/such/dir/ input 2>&1 | FileCheck %s
+// RUN: %clang -### -working-directory %p/Inputs no_such_file.cpp -c 2>&1 | FileCheck %s --check-prefix=CHECK_NO_FILE
+// RUN: %clang -### -working-directory %p/Inputs pchfile.cpp -c 2>&1 | FileCheck %s --check-prefix=CHECK_WORKS
 
-//CHECK: no such file or directory: '/no/such/dir/input'
+// CHECK: unable to set working directory: /no/such/dir/
+
+// CHECK_NO_FILE: no such file or directory: 'no_such_file.cpp'
+
+// CHECK_WORKS: "-coverage-notes-file" "{{[^"]+}}test{{/|\\\\}}Driver{{/|\\\\}}Inputs{{/|\\\\}}pchfile.gcno"
+// CHECK_WORKS: "-working-directory" "{{[^"]+}}test{{/|\\\\}}Driver{{/|\\\\}}Inputs"
+// CHECK_WORKS: "-fdebug-compilation-dir" "{{[^"]+}}test{{/|\\\\}}Driver{{/|\\\\}}Inputs"