Add support for passing the main file name down to the assembler

for location information.

Part of PR14624

llvm-svn: 170391

clang/include/clang/Driver/CC1AsOptions.td

@@ -37,6 +37,8 @@ def L : Flag<["-"], "L">,
   HelpText<"Save temporary labels in the symbol table. "
            "Note this may change .s semantics, it should almost never be used "
            "on compiler generated code!">;
+def main_file_name : Separate<["-"], "main-file-name">,
+  HelpText<"Main file name to use for debug info">;
 
 //===----------------------------------------------------------------------===//
 // Frontend Options

clang/lib/Driver/Tools.cpp

@@ -3278,6 +3278,11 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back("-filetype");
   CmdArgs.push_back("obj");
 
+  // Set the main file name, so that debug info works even with
+  // -save-temps or preprocessed assembly.
+  CmdArgs.push_back("-main-file-name");
+  CmdArgs.push_back(Clang::getBaseInputName(Args, Inputs));
+
   if (UseRelaxAll(C, Args))
     CmdArgs.push_back("-relax-all");
 

clang/lib/Driver/Tools.h

@@ -30,6 +30,7 @@ namespace tools {
 
   /// \brief Clang compiler tool.
   class LLVM_LIBRARY_VISIBILITY Clang : public Tool {
+  public:
     static const char *getBaseInputName(const ArgList &Args,
                                         const InputInfoList &Inputs);
     static const char *getBaseInputStem(const ArgList &Args,
@@ -37,6 +38,7 @@ namespace tools {
     static const char *getDependencyFileName(const ArgList &Args,
                                              const InputInfoList &Inputs);
 
+  private:
     void AddPreprocessingOptions(Compilation &C,
                                  const Driver &D,
                                  const ArgList &Args,

clang/test/Driver/debug-main-file.S

@@ -0,0 +1,12 @@
+// REQUIRES: clang-driver
+// RUN: %clang -### -c -save-temps -integrated-as -g %s 2>&1 \
+// RUN:   | FileCheck %s
+
+// CHECK: main-file-name
+
+#ifdef(1)
+foo:
+        nop
+        nop
+        nop
+#endif

clang/tools/driver/cc1as_main.cpp

@@ -84,6 +84,7 @@ struct AssemblerInvocation {
   unsigned GenDwarfForAssembly : 1;
   std::string DwarfDebugFlags;
   std::string DebugCompilationDir;
+  std::string MainFileName;
 
   /// @}
   /// @name Frontend Options
@@ -183,6 +184,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
   Opts.GenDwarfForAssembly = Args->hasArg(OPT_g);
   Opts.DwarfDebugFlags = Args->getLastArgValue(OPT_dwarf_debug_flags);
   Opts.DebugCompilationDir = Args->getLastArgValue(OPT_fdebug_compilation_dir);
+  Opts.MainFileName = Args->getLastArgValue(OPT_main_file_name);
 
   // Frontend Options
   if (Args->hasArg(OPT_INPUT)) {
@@ -309,6 +311,8 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts,
     Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
   if (!Opts.DebugCompilationDir.empty())
     Ctx.setCompilationDir(Opts.DebugCompilationDir);
+  if (!Opts.MainFileName.empty())
+    Ctx.setMainFileName(StringRef(Opts.MainFileName));
 
   // Build up the feature string from the target feature list.
   std::string FS;