ARM: allow .thumb_func to be separated from symbol definition

When assembling, a .thumb_func directive is supposed to be applicable to the
next symbol definition, even if there are intervening directives. We were
racing ahead to try and find it, and this commit should fix the issue.

Patch by Gabor Ballabas

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193403 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCTargetAsmParser.h

@@ -181,6 +181,8 @@ public:
                                             MCContext &Ctx) {
     return 0;
   }
+
+  virtual void onLabelParsed(MCSymbol *Symbol) { };
 };
 
 } // End llvm namespace

lib/MC/MCParser/AsmParser.cpp

@@ -1262,6 +1262,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info) {
       MCGenDwarfLabelEntry::Make(Sym, &getStreamer(), getSourceManager(),
                                  IDLoc);
 
+    getTargetParser().onLabelParsed(Sym);
+
     // Consume any end of statement token, if present, to avoid spurious
     // AddBlankLine calls().
     if (Lexer.is(AsmToken::EndOfStatement)) {

lib/Target/ARM/AsmParser/ARMAsmParser.cpp

@@ -74,6 +74,8 @@ class ARMAsmParser : public MCTargetAsmParser {
   // Map of register aliases registers via the .req directive.
   StringMap<unsigned> RegisterReqs;
 
+  bool NextSymbolIsThumb;
+
   struct {
     ARMCC::CondCodes Cond;    // Condition for IT block.
     unsigned Mask:4;          // Condition mask for instructions.
@@ -268,6 +270,8 @@ public:
 
     // Not in an ITBlock to start with.
     ITState.CurPosition = ~0U;
+
+    NextSymbolIsThumb = false;
   }
 
   // Implementation of the MCTargetAsmParser interface:
@@ -284,6 +288,8 @@ public:
                                SmallVectorImpl<MCParsedAsmOperand*> &Operands,
                                MCStreamer &Out, unsigned &ErrorInfo,
                                bool MatchingInlineAsm);
+  void onLabelParsed(MCSymbol *Symbol);
+
 };
 } // end anonymous namespace
 
@@ -7837,13 +7843,18 @@ bool ARMAsmParser::parseDirectiveARM(SMLoc L) {
   return false;
 }
 
+void ARMAsmParser::onLabelParsed(MCSymbol *Symbol) {
+  if (NextSymbolIsThumb) {
+    getParser().getStreamer().EmitThumbFunc(Symbol);
+    NextSymbolIsThumb = false;
+  }
+}
+
 /// parseDirectiveThumbFunc
 ///  ::= .thumbfunc symbol_name
 bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
   const MCAsmInfo *MAI = getParser().getStreamer().getContext().getAsmInfo();
   bool isMachO = MAI->hasSubsectionsViaSymbols();
-  StringRef Name;
-  bool needFuncName = true;
 
   // Darwin asm has (optionally) function name after .thumb_func direction
   // ELF doesn't
@@ -7852,29 +7863,19 @@ bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
     if (Tok.isNot(AsmToken::EndOfStatement)) {
       if (Tok.isNot(AsmToken::Identifier) && Tok.isNot(AsmToken::String))
         return Error(L, "unexpected token in .thumb_func directive");
-      Name = Tok.getIdentifier();
+      MCSymbol *Func =
+          getParser().getContext().GetOrCreateSymbol(Tok.getIdentifier());
+      getParser().getStreamer().EmitThumbFunc(Func);
       Parser.Lex(); // Consume the identifier token.
-      needFuncName = false;
+      return false;
     }
   }
 
   if (getLexer().isNot(AsmToken::EndOfStatement))
     return Error(L, "unexpected token in directive");
 
-  // Eat the end of statement and any blank lines that follow.
+  NextSymbolIsThumb = true;
-  while (getLexer().is(AsmToken::EndOfStatement))
-    Parser.Lex();
 
-  // FIXME: assuming function name will be the line following .thumb_func
-  // We really should be checking the next symbol definition even if there's
-  // stuff in between.
-  if (needFuncName) {
-    Name = Parser.getTok().getIdentifier();
-  }
-
-  // Mark symbol as a thumb symbol.
-  MCSymbol *Func = getParser().getContext().GetOrCreateSymbol(Name);
-  getParser().getStreamer().EmitThumbFunc(Func);
   return false;
 }
 

test/MC/ARM/elf-thumbfunc.s

@@ -5,9 +5,9 @@
 	.text
 	.globl	foo
 	.align	2
-	.type	foo,%function
 	.code	16
 	.thumb_func
+	.type	foo,%function
 foo:
 	bx	lr