Fix PR14625 by teaching the driver to detect PWD for assembly files.

This also requires adding support to -cc1as for passing the detecting
PWD down through LLVM's debug info (which in turn required the LLVM
change in r170371).

The test case is weak (we only test the driver behavior) because there
is currently to infrastructure for running cc1as in the test suite. So
those four lines are untested (much like all other lines in that file),
but we have a test for the same pattern using llvm-mc in the LLVM
repository.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170373 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 39 insertions, 10 deletions

diff --git a/include/clang/Driver/CC1AsOptions.td b/include/clang/Driver/CC1AsOptions.td
index 9fd855a9ce..620d721506 100644
--- a/include/clang/Driver/CC1AsOptions.td
+++ b/include/clang/Driver/CC1AsOptions.td
@@ -86,5 +86,8 @@ def fatal_warnings : Flag<["--"], "fatal-warnings">,
 
 def g : Flag<["-"], "g">, HelpText<"Generate source level debug information">;
 
+def fdebug_compilation_dir : Separate<["-"], "fdebug-compilation-dir">,
+  HelpText<"The compilation directory to embed in the debug info.">;
+
 def dwarf_debug_flags : Separate<["-"], "dwarf-debug-flags">,
   HelpText<"The string to embed in the Dwarf debug flags record.">;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 2737c1a88a..bbc3cccef3 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1611,6 +1611,20 @@ static bool shouldUseFramePointer(const ArgList &Args,
   return true;
 }
 
+/// If the PWD environment variable is set, add a CC1 option to specify the
+/// debug compilation directory.
+static void addDebugCompDirArg(const ArgList &Args, ArgStringList &CmdArgs) {
+  if (const char *pwd = ::getenv("PWD")) {
+    // GCC also verifies that stat(pwd) and stat(".") have the same inode
+    // number. Not doing those because stats are slow, but we could.
+    if (llvm::sys::path::is_absolute(pwd)) {
+      std::string CompDir = pwd;
+      CmdArgs.push_back("-fdebug-compilation-dir");
+      CmdArgs.push_back(Args.MakeArgString(CompDir));
+    }
+  }
+}
+
 void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                          const InputInfo &Output,
                          const InputInfoList &Inputs,
@@ -2362,15 +2376,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (ShouldDisableDwarfDirectory(Args, getToolChain()))
     CmdArgs.push_back("-fno-dwarf-directory-asm");
 
-  if (const char *pwd = ::getenv("PWD")) {
-    // GCC also verifies that stat(pwd) and stat(".") have the same inode
-    // number. Not doing those because stats are slow, but we could.
-    if (llvm::sys::path::is_absolute(pwd)) {
-      std::string CompDir = pwd;
-      CmdArgs.push_back("-fdebug-compilation-dir");
-      CmdArgs.push_back(Args.MakeArgString(CompDir));
-    }
-  }
+  // Add in -fdebug-compilation-dir if necessary.
+  addDebugCompDirArg(Args, CmdArgs);
 
   if (Arg *A = Args.getLastArg(options::OPT_ftemplate_depth_,
                                options::OPT_ftemplate_depth_EQ)) {
@@ -3295,13 +3302,17 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
     SourceAction = SourceAction->getInputs()[0];
   }
 
-  // Forward -g, assuming we are dealing with an actual assembly file.
+  // Forward -g and handle debug info related flags, assuming we are dealing
+  // with an actual assembly file.
   if (SourceAction->getType() == types::TY_Asm ||
       SourceAction->getType() == types::TY_PP_Asm) {
     Args.ClaimAllArgs(options::OPT_g_Group);
     if (Arg *A = Args.getLastArg(options::OPT_g_Group))
       if (!A->getOption().matches(options::OPT_g0))
         CmdArgs.push_back("-g");
+
+    // Add the -fdebug-compilation-dir flag if needed.
+    addDebugCompDirArg(Args, CmdArgs);
   }
 
   // Optionally embed the -cc1as level arguments into the debug info, for build
diff --git a/test/Driver/debug-comp-dir.S b/test/Driver/debug-comp-dir.S
new file mode 100644
index 0000000000..ca1ca30ae6
--- /dev/null
+++ b/test/Driver/debug-comp-dir.S
@@ -0,0 +1,11 @@
+// RUN: cd %S && %clang -### -g %s -c 2>&1 | FileCheck -check-prefix=CHECK-PWD %s
+// CHECK-PWD: {{"-fdebug-compilation-dir" ".*Driver.*"}}
+
+// RUN: env PWD=/foo %clang -### -g %s -c 2>&1 | FileCheck -check-prefix=CHECK-FOO %s
+// CHECK-FOO: {{"-fdebug-compilation-dir" ".*foo"}}
+
+// "PWD=/foo gcc" wouldn't necessarily work. You would need to pick a different
+// path to the same directory (try a symlink).
+
+// This depends on host's behavior how $PWD would be set.
+// REQUIRES: shell
diff --git a/tools/driver/cc1as_main.cpp b/tools/driver/cc1as_main.cpp
index 87e3bfba84..73be56c2b4 100644
--- a/tools/driver/cc1as_main.cpp
+++ b/tools/driver/cc1as_main.cpp
@@ -83,6 +83,7 @@ struct AssemblerInvocation {
   unsigned SaveTemporaryLabels : 1;
   unsigned GenDwarfForAssembly : 1;
   std::string DwarfDebugFlags;
+  std::string DebugCompilationDir;
 
   /// @}
   /// @name Frontend Options
@@ -181,6 +182,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
   Opts.SaveTemporaryLabels = Args->hasArg(OPT_L);
   Opts.GenDwarfForAssembly = Args->hasArg(OPT_g);
   Opts.DwarfDebugFlags = Args->getLastArgValue(OPT_dwarf_debug_flags);
+  Opts.DebugCompilationDir = Args->getLastArgValue(OPT_fdebug_compilation_dir);
 
   // Frontend Options
   if (Args->hasArg(OPT_INPUT)) {
@@ -305,6 +307,8 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts,
     Ctx.setGenDwarfForAssembly(true);
   if (!Opts.DwarfDebugFlags.empty())
     Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
+  if (!Opts.DebugCompilationDir.empty())
+    Ctx.setCompilationDir(Opts.DebugCompilationDir);
 
   // Build up the feature string from the target feature list.
   std::string FS;