Use .cfi_sections to put the unwind info in .debug_frame when possible. With

this clang will use .debug_frame in, for example,
clang -g -c -m32 test.c
This matches gcc's behaviour. It looks like .debug_frame is a bit bigger
than .eh_frame, but has the big advantage of not being allocated.

llvm-svn: 131140

1 files changed, 10 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index dbd52c4981b..e7a7593be3b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -49,6 +49,9 @@ DwarfCFIException::~DwarfCFIException() {}
 /// EndModule - Emit all exception information that should come after the
 /// content.
 void DwarfCFIException::EndModule() {
+  if (moveTypeModule == AsmPrinter::CFI_M_Debug)
+    Asm->OutStreamer.EmitCFISections(false, true);
+
   if (!Asm->MAI->isExceptionHandlingDwarf())
     return;
 
@@ -87,7 +90,13 @@ void DwarfCFIException::BeginFunction(const MachineFunction *MF) {
   bool hasLandingPads = !MMI->getLandingPads().empty();
 
   // See if we need frame move info.
-  shouldEmitMoves = Asm->needsCFIMoves();
+  AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
+  if (MoveType == AsmPrinter::CFI_M_EH ||
+      (MoveType == AsmPrinter::CFI_M_Debug &&
+       moveTypeModule == AsmPrinter::CFI_M_None))
+    moveTypeModule = MoveType;
+
+  shouldEmitMoves = MoveType != AsmPrinter::CFI_M_None;
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   unsigned PerEncoding = TLOF.getPersonalityEncoding();