There is only one current section.

Both MCStreamer and MCObjectStreamer were maintaining a current section
variable and they were slightly out of sync. I don't think this was observable,
but was inefficient and error prone.

Changing this requires a few cascading changes:

* SwitchSection has to call ChangeSection earlier for ChangeSection to see
  the old section.
* With that change, ChangeSection cannot call EmitLabel, since during
  ChangeSection we are still in the old section.
* When the object streamer requires a begin label, just reused the existing
  generic support for begin labels instead of calling EmitLabel directly.

llvm-svn: 238357

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
index 87b15ff..fa124f3 100644
--- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -537,9 +537,11 @@ EndStmt:
       if (getContext().getDwarfVersion() <= 2)
         Warning(loc, "DWARF2 only supports one section per compilation unit");
 
-      MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
-      getStreamer().EmitLabel(SectionStartSymbol);
-      ELFSection->setBeginSymbol(SectionStartSymbol);
+      if (!ELFSection->getBeginSymbol()) {
+        MCSymbol *SectionStartSymbol = getContext().createTempSymbol();
+        getStreamer().EmitLabel(SectionStartSymbol);
+        ELFSection->setBeginSymbol(SectionStartSymbol);
+      }
     }
   }