Merge from head up to r262611.

3 files changed, 9 insertions, 5 deletions

diff --git a/contrib/llvm/include/llvm/MC/MCContext.h b/contrib/llvm/include/llvm/MC/MCContext.h
index c8b6626..17a37ed 100644
--- a/contrib/llvm/include/llvm/MC/MCContext.h
+++ b/contrib/llvm/include/llvm/MC/MCContext.h
@@ -278,6 +278,7 @@ namespace llvm {
     /// This can be overridden by clients which want to control the reported
     /// compilation directory and have it be something other than the current
     /// working directory.
+    /// Returns an empty string if the current directory cannot be determined.
     StringRef getCompilationDir() const { return CompilationDir; }
 
     /// \brief Set the compilation directory for DW_AT_comp_dir
diff --git a/contrib/llvm/lib/MC/MCContext.cpp b/contrib/llvm/lib/MC/MCContext.cpp
index 3b45d16..a0acda5 100644
--- a/contrib/llvm/lib/MC/MCContext.cpp
+++ b/contrib/llvm/lib/MC/MCContext.cpp
@@ -47,8 +47,8 @@ MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
   AllowTemporaryLabels(true), DwarfCompileUnitID(0), AutoReset(DoAutoReset) {
 
   error_code EC = llvm::sys::fs::current_path(CompilationDir);
-  assert(!EC && "Could not determine the current directory");
-  (void)EC;
+  if (EC)
+    CompilationDir.clear();
 
   MachOUniquingMap = 0;
   ELFUniquingMap = 0;
diff --git a/contrib/llvm/lib/MC/MCDwarf.cpp b/contrib/llvm/lib/MC/MCDwarf.cpp
index 1e5c2e3..479f445 100644
--- a/contrib/llvm/lib/MC/MCDwarf.cpp
+++ b/contrib/llvm/lib/MC/MCDwarf.cpp
@@ -467,7 +467,8 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
   EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
   EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
   EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
-  EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
+  if (!context.getCompilationDir().empty())
+    EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
   StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
   if (!DwarfDebugFlags.empty())
     EmitAbbrev(MCOS, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string);
@@ -643,8 +644,10 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS,
   MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
 
   // AT_comp_dir, the working directory the assembly was done in.
-  MCOS->EmitBytes(context.getCompilationDir());
-  MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
+  if (!context.getCompilationDir().empty()) {
+    MCOS->EmitBytes(context.getCompilationDir());
+    MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
+  }
 
   // AT_APPLE_flags, the command line arguments of the assembler tool.
   StringRef DwarfDebugFlags = context.getDwarfDebugFlags();