Downgrade DWARF2 section limit error to a warning

We currently emit an error when trying to assemble a file with more
than one section using DWARF2 debug info. This should be a warning
instead, as the resulting file will still be usable, but with a
degraded debug illusion.

llvm-svn: 218241

1 files changed, 6 insertions, 4 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 95cfe24eaae..9993588cfab 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -536,7 +536,8 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
   MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
   MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1);
   EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4);
-  if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1) {
+  if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
+      MCOS->getContext().getDwarfVersion() >= 3) {
     EmitAbbrev(MCOS, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4);
   } else {
     EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
@@ -873,10 +874,11 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) {
   if (MCOS->getContext().getGenDwarfSectionSyms().empty())
     return;
 
-  // We only need to use the .debug_ranges section if we have multiple
-  // code sections.
+  // We only use the .debug_ranges section if we have multiple code sections,
+  // and we are emitting a DWARF version which supports it.
   const bool UseRangesSection =
-      MCOS->getContext().getGenDwarfSectionSyms().size() > 1;
+      MCOS->getContext().getGenDwarfSectionSyms().size() > 1 &&
+      MCOS->getContext().getDwarfVersion() >= 3;
   CreateDwarfSectionSymbols |= UseRangesSection;
 
   MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection());