[NVPTX] Initial adaptation of MCAsmStreamer/MCTargetStreamer for debug info in Cuda.

Summary:
Initial changes in interfaces of MCAsmStreamer/MCTargetStreamer for
correct debug info emission for Cuda.
1. PTX foramt does not support `.ascii` directives. Added the ability to
nullify it.
2. The initial function label must follow the first debug `.loc`
directive, not be followed by.
3. DWARF sections must be enclosed in braces.

Reviewers: hfinkel, probinson, jlebar, rafael, echristo

Subscribers: sdardis, nemanjai, llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D40033

llvm-svn: 321178

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 6f3647d6193..6e801ed8777 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -49,6 +49,28 @@ void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
 
 void MCTargetStreamer::finish() {}
 
+void MCTargetStreamer::changeSection(const MCSection *CurSection,
+                                     MCSection *Section,
+                                     const MCExpr *Subsection,
+                                     raw_ostream &OS) {
+  Section->PrintSwitchToSection(
+      *Streamer.getContext().getAsmInfo(),
+      Streamer.getContext().getObjectFileInfo()->getTargetTriple(), OS,
+      Subsection);
+}
+
+void MCTargetStreamer::emitDwarfFileDirective(StringRef Directive) {
+  Streamer.EmitRawText(Directive);
+}
+
+void MCTargetStreamer::emitValue(const MCExpr *Value) {
+  SmallString<128> Str;
+  raw_svector_ostream OS(Str);
+
+  Value->print(OS, Streamer.getContext().getAsmInfo());
+  Streamer.EmitRawText(OS.str());
+}
+
 void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
 
 MCStreamer::MCStreamer(MCContext &Ctx)