[CodeGen] prevent abnormal on invalid attributes

Currently, when an invalid attribute is encountered on processing a .s file,
clang will abort due to llvm_unreachable.  Invalid user input should not cause
an abnormal termination of the compiler.  Change the interface to return a
boolean to indicate the failure as a first step towards improving hanlding of
malformed user input to clang.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 188047

1 files changed, 6 insertions, 4 deletions

diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index 6e5ff50e378..4661d503c37 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -148,8 +148,8 @@ static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) {
   return T2;
 }
 
-void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
-                                          MCSymbolAttr Attribute) {
+bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
+                                        MCSymbolAttr Attribute) {
   // Indirect symbols are handled differently, to match how 'as' handles
   // them. This makes writing matching .o files easier.
   if (Attribute == MCSA_IndirectSymbol) {
@@ -159,7 +159,7 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
     ISD.Symbol = Symbol;
     ISD.SectionData = getCurrentSectionData();
     getAssembler().getIndirectSymbols().push_back(ISD);
-    return;
+    return true;
   }
 
   // Adding a symbol attribute always introduces the symbol, note that an
@@ -182,7 +182,7 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
   case MCSA_WeakDefAutoPrivate:
   case MCSA_Invalid:
   case MCSA_IndirectSymbol:
-    llvm_unreachable("Invalid symbol attribute for ELF!");
+    return false;
 
   case MCSA_NoDeadStrip:
   case MCSA_ELF_TypeGnuUniqueObject:
@@ -251,6 +251,8 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
     MCELF::SetVisibility(SD, ELF::STV_INTERNAL);
     break;
   }
+
+  return true;
 }
 
 void MCELFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,