[Clang] Use -main-file-name for source filename if not set

-main-file-name is currently used to set the source name used in debug
information.

If the source filename is "-" and -main-file-name is set, then use the
filename also for source_filename and ModuleID of the output.

The argument is generally used outside the internal clang calls when
running clang in a wrapper like icecc which gives the source via stdin
but still wants to get a object file with the original source filename
both in debug info and IR code.

Patch by: the_jk (Joel Klinghed)

Differential Revision: https://reviews.llvm.org/D67592

llvm-svn: 373217

1 files changed, 10 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 414a6b8..4154f6eb 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -65,6 +65,13 @@ namespace {
   private:
     SmallVector<FunctionDecl *, 8> DeferredInlineMemberFuncDefs;
 
+    static llvm::StringRef ExpandModuleName(llvm::StringRef ModuleName,
+                                            const CodeGenOptions &CGO) {
+      if (ModuleName == "-" && !CGO.MainFileName.empty())
+        return CGO.MainFileName;
+      return ModuleName;
+    }
+
   public:
     CodeGeneratorImpl(DiagnosticsEngine &diags, llvm::StringRef ModuleName,
                       const HeaderSearchOptions &HSO,
@@ -73,7 +80,8 @@ namespace {
                       CoverageSourceInfo *CoverageInfo = nullptr)
         : Diags(diags), Ctx(nullptr), HeaderSearchOpts(HSO),
           PreprocessorOpts(PPO), CodeGenOpts(CGO), HandlingTopLevelDecls(0),
-          CoverageInfo(CoverageInfo), M(new llvm::Module(ModuleName, C)) {
+          CoverageInfo(CoverageInfo),
+          M(new llvm::Module(ExpandModuleName(ModuleName, CGO), C)) {
       C.setDiscardValueNames(CGO.DiscardValueNames);
     }
 
@@ -121,7 +129,7 @@ namespace {
     llvm::Module *StartModule(llvm::StringRef ModuleName,
                               llvm::LLVMContext &C) {
       assert(!M && "Replacing existing Module?");
-      M.reset(new llvm::Module(ModuleName, C));
+      M.reset(new llvm::Module(ExpandModuleName(ModuleName, CodeGenOpts), C));
       Initialize(*Ctx);
       return M.get();
     }