sets bit 0 of the function address of thumb function in .symtab

("T is 1 if the target symbol S has type STT_FUNC and the
symbol addresses a Thumb instruction ;it is 0 otherwise."
from "ELF for the ARM Architecture" 4.7.1.2)

Patch by Koan-Sin Tan!

llvm-svn: 131406

2 files changed, 21 insertions, 6 deletions

diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index f90d3756b37..93282701d85 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -274,7 +274,7 @@ void ARMAsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
 void ARMAsmPrinter::EmitFunctionEntryLabel() {
   if (AFI->isThumbFunction()) {
     OutStreamer.EmitAssemblerFlag(MCAF_Code16);
-    OutStreamer.EmitThumbFunc(Subtarget->isTargetDarwin()? CurrentFnSym : 0);
+    OutStreamer.EmitThumbFunc(CurrentFnSym);
   }
 
   OutStreamer.EmitLabel(CurrentFnSym);
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 29ecc182d31..401894e75e1 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -15,6 +15,7 @@
 #include "llvm/MC/MCParser/MCAsmLexer.h"
 #include "llvm/MC/MCParser/MCAsmParser.h"
 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
+#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCExpr.h"
@@ -2099,15 +2100,29 @@ bool ARMAsmParser::ParseDirectiveThumb(SMLoc L) {
 /// ParseDirectiveThumbFunc
 ///  ::= .thumbfunc symbol_name
 bool ARMAsmParser::ParseDirectiveThumbFunc(SMLoc L) {
-  const AsmToken &Tok = Parser.getTok();
-  if (Tok.isNot(AsmToken::Identifier) && Tok.isNot(AsmToken::String))
-    return Error(L, "unexpected token in .thumb_func directive");
-  StringRef Name = Tok.getString();
-  Parser.Lex(); // Consume the identifier token.
+  const MCAsmInfo &MAI = getParser().getStreamer().getContext().getAsmInfo();
+  bool isMachO = MAI.hasSubsectionsViaSymbols();
+  StringRef Name;
+
+  // Darwin asm has function name after .thumb_func direction
+  // ELF doesn't
+  if (isMachO) {
+    const AsmToken &Tok = Parser.getTok();
+    if (Tok.isNot(AsmToken::Identifier) && Tok.isNot(AsmToken::String))
+      return Error(L, "unexpected token in .thumb_func directive");
+    Name = Tok.getString();
+    Parser.Lex(); // Consume the identifier token.
+  }
+
   if (getLexer().isNot(AsmToken::EndOfStatement))
     return Error(L, "unexpected token in directive");
   Parser.Lex();
 
+  // FIXME: assuming function name will be the line following .thumb_func
+  if (!isMachO) {
+    Name = Parser.getTok().getString();
+  }
+
   // Mark symbol as a thumb symbol.
   MCSymbol *Func = getParser().getContext().GetOrCreateSymbol(Name);
   getParser().getStreamer().EmitThumbFunc(Func);