[ARM] Use dwarf exception handling on MinGW

Enabling and using dwarf exceptions seems like an easier path
to take, than to make the COFF/ARM backend output EHABI directives.
Previously, no EH model was enabled at all on this target.

There's no point in setting UseIntegratedAssembler to false since
GNU binutils doesn't support Windows on ARM, and since we don't
need to support external assembler, we don't need to use register
numbers in cfi directives.

Differential Revision: https://reviews.llvm.org/D39532

llvm-svn: 318510

2 files changed, 10 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
index 608e1e01f8c..177b636077b 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
@@ -105,10 +105,10 @@ ARMCOFFMCAsmInfoGNU::ARMCOFFMCAsmInfoGNU() {
   PrivateLabelPrefix = ".L";
 
   SupportsDebugInformation = true;
-  ExceptionsType = ExceptionHandling::None;
+  ExceptionsType = ExceptionHandling::DwarfCFI;
   UseParensForSymbolVariant = true;
 
-  UseIntegratedAssembler = false;
-  DwarfRegNumForCFI = true;
+  UseIntegratedAssembler = true;
+  DwarfRegNumForCFI = false;
 }
 
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFStreamer.cpp
index ba9246eafa9..a2424e1abab 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFStreamer.cpp
@@ -23,6 +23,7 @@ public:
 
   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
   void EmitThumbFunc(MCSymbol *Symbol) override;
+  void FinishImpl() override;
 };
 
 void ARMWinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
@@ -37,6 +38,12 @@ void ARMWinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
 void ARMWinCOFFStreamer::EmitThumbFunc(MCSymbol *Symbol) {
   getAssembler().setIsThumbFunc(Symbol);
 }
+
+void ARMWinCOFFStreamer::FinishImpl() {
+  EmitFrames(nullptr);
+
+  MCWinCOFFStreamer::FinishImpl();
+}
 }
 
 MCStreamer *llvm::createARMWinCOFFStreamer(