correct target directive handling error handling

The target specific parser should return `false' if the target AsmParser handles
the directive, and `true' if the generic parser should handle the directive.
Many of the target specific directive handlers would `return Error' which does
not follow these semantics.  This change simply changes the target specific
routines to conform to the semantis of the ParseDirective correctly.

Conformance to the semantics improves diagnostics emitted for the invalid
directives.  X86 is taken as a sample to ensure that multiple diagnostics are
not presented for a single error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199068 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 119 insertions, 64 deletions

diff --git a/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index 8c144a625b..e335361530 100644
--- a/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -2291,7 +2291,7 @@ bool AArch64AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
     for (;;) {
       const MCExpr *Value;
       if (getParser().parseExpression(Value))
-        return true;
+        return false;
 
       getParser().getStreamer().EmitValue(Value, Size);
 
@@ -2299,8 +2299,10 @@ bool AArch64AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
         break;
 
       // FIXME: Improve diagnostic.
-      if (getLexer().isNot(AsmToken::Comma))
-        return Error(L, "unexpected token in directive");
+      if (getLexer().isNot(AsmToken::Comma)) {
+        Error(L, "unexpected token in directive");
+        return false;
+      }
       Parser.Lex();
     }
   }
@@ -2313,8 +2315,10 @@ bool AArch64AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
 //   ::= .tlsdesccall symbol
 bool AArch64AsmParser::ParseDirectiveTLSDescCall(SMLoc L) {
   StringRef Name;
-  if (getParser().parseIdentifier(Name))
-    return Error(L, "expected symbol after directive");
+  if (getParser().parseIdentifier(Name)) {
+    Error(L, "expected symbol after directive");
+    return false;
+  }
 
   MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
   const MCSymbolRefExpr *Expr = MCSymbolRefExpr::Create(Sym, getContext());
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index b8890a37df..6cd3657ff3 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -8072,7 +8072,7 @@ bool ARMAsmParser::parseDirectiveWord(unsigned Size, SMLoc L) {
     for (;;) {
       const MCExpr *Value;
       if (getParser().parseExpression(Value))
-        return true;
+        return false;
 
       getParser().getStreamer().EmitValue(Value, Size);
 
@@ -8080,8 +8080,10 @@ bool ARMAsmParser::parseDirectiveWord(unsigned Size, SMLoc L) {
         break;
 
       // FIXME: Improve diagnostic.
-      if (getLexer().isNot(AsmToken::Comma))
-        return Error(L, "unexpected token in directive");
+      if (getLexer().isNot(AsmToken::Comma)) {
+        Error(L, "unexpected token in directive");
+        return false;
+      }
       Parser.Lex();
     }
   }
@@ -8093,12 +8095,16 @@ bool ARMAsmParser::parseDirectiveWord(unsigned Size, SMLoc L) {
 /// parseDirectiveThumb
 ///  ::= .thumb
 bool ARMAsmParser::parseDirectiveThumb(SMLoc L) {
-  if (getLexer().isNot(AsmToken::EndOfStatement))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
   Parser.Lex();
 
-  if (!hasThumb())
-    return Error(L, "target does not support Thumb mode");
+  if (!hasThumb()) {
+    Error(L, "target does not support Thumb mode");
+    return false;
+  }
 
   if (!isThumb())
     SwitchMode();
@@ -8109,12 +8115,16 @@ bool ARMAsmParser::parseDirectiveThumb(SMLoc L) {
 /// parseDirectiveARM
 ///  ::= .arm
 bool ARMAsmParser::parseDirectiveARM(SMLoc L) {
-  if (getLexer().isNot(AsmToken::EndOfStatement))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
   Parser.Lex();
 
-  if (!hasARM())
-    return Error(L, "target does not support ARM mode");
+  if (!hasARM()) {
+    Error(L, "target does not support ARM mode");
+    return false;
+  }
 
   if (isThumb())
     SwitchMode();
@@ -8140,8 +8150,11 @@ bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
   if (isMachO) {
     const AsmToken &Tok = Parser.getTok();
     if (Tok.isNot(AsmToken::EndOfStatement)) {
-      if (Tok.isNot(AsmToken::Identifier) && Tok.isNot(AsmToken::String))
-        return Error(L, "unexpected token in .thumb_func directive");
+      if (Tok.isNot(AsmToken::Identifier) && Tok.isNot(AsmToken::String)) {
+        Error(L, "unexpected token in .thumb_func directive");
+        return false;
+      }
+
       MCSymbol *Func =
           getParser().getContext().GetOrCreateSymbol(Tok.getIdentifier());
       getParser().getStreamer().EmitThumbFunc(Func);
@@ -8150,11 +8163,12 @@ bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
     }
   }
 
-  if (getLexer().isNot(AsmToken::EndOfStatement))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
 
   NextSymbolIsThumb = true;
-
   return false;
 }
 
@@ -8162,15 +8176,21 @@ bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
 ///  ::= .syntax unified | divided
 bool ARMAsmParser::parseDirectiveSyntax(SMLoc L) {
   const AsmToken &Tok = Parser.getTok();
-  if (Tok.isNot(AsmToken::Identifier))
-    return Error(L, "unexpected token in .syntax directive");
+  if (Tok.isNot(AsmToken::Identifier)) {
+    Error(L, "unexpected token in .syntax directive");
+    return false;
+  }
+
   StringRef Mode = Tok.getString();
-  if (Mode == "unified" || Mode == "UNIFIED")
+  if (Mode == "unified" || Mode == "UNIFIED") {
     Parser.Lex();
-  else if (Mode == "divided" || Mode == "DIVIDED")
-    return Error(L, "'.syntax divided' arm asssembly not supported");
-  else
-    return Error(L, "unrecognized syntax mode in .syntax directive");
+  } else if (Mode == "divided" || Mode == "DIVIDED") {
+    Error(L, "'.syntax divided' arm asssembly not supported");
+    return false;
+  } else {
+    Error(L, "unrecognized syntax mode in .syntax directive");
+    return false;
+  }
 
   if (getLexer().isNot(AsmToken::EndOfStatement)) {
     Error(Parser.getTok().getLoc(), "unexpected token in directive");
@@ -8676,7 +8696,7 @@ bool ARMAsmParser::parseDirectiveRegSave(SMLoc L, bool IsVector) {
 
   // Parse the register list
   if (parseRegisterList(CO.Operands))
-    return true;
+    return false;
   ARMOperand *Op = (ARMOperand*)CO.Operands[0];
   if (!IsVector && !Op->isRegList()) {
     Error(L, ".save expects GPR registers");
diff --git a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index de39107441..9df2df2dac 100644
--- a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -2407,13 +2407,17 @@ bool MipsAsmParser::parseDirectiveMipsHackStocg() {
     reportParseError("expected identifier");
 
   MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
-  if (getLexer().isNot(AsmToken::Comma))
-    return TokError("unexpected token");
+  if (getLexer().isNot(AsmToken::Comma)) {
+    TokError("unexpected token");
+    return false;
+  }
   Lex();
 
   int64_t Flags = 0;
-  if (Parser.parseAbsoluteExpression(Flags))
-    return TokError("unexpected token");
+  if (Parser.parseAbsoluteExpression(Flags)) {
+    TokError("unexpected token");
+    return false;
+  }
 
   getTargetStreamer().emitMipsHackSTOCG(Sym, Flags);
   return false;
@@ -2421,8 +2425,10 @@ bool MipsAsmParser::parseDirectiveMipsHackStocg() {
 
 bool MipsAsmParser::parseDirectiveMipsHackELFFlags() {
   int64_t Flags = 0;
-  if (Parser.parseAbsoluteExpression(Flags))
-    return TokError("unexpected token");
+  if (Parser.parseAbsoluteExpression(Flags)) {
+    TokError("unexpected token");
+    return false;
+  }
 
   getTargetStreamer().emitMipsHackELFFlags(Flags);
   return false;
@@ -2499,7 +2505,6 @@ bool MipsAsmParser::parseDirectiveOption() {
 }
 
 bool MipsAsmParser::ParseDirective(AsmToken DirectiveID) {
-
   StringRef IDVal = DirectiveID.getString();
 
   if (IDVal == ".ent") {
diff --git a/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp b/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
index a027606f1e..0455686599 100644
--- a/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
+++ b/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
@@ -1373,7 +1373,7 @@ bool PPCAsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
     for (;;) {
       const MCExpr *Value;
       if (getParser().parseExpression(Value))
-        return true;
+        return false;
 
       getParser().getStreamer().EmitValue(Value, Size);
 
@@ -1397,8 +1397,10 @@ bool PPCAsmParser::ParseDirectiveTC(unsigned Size, SMLoc L) {
   while (getLexer().isNot(AsmToken::EndOfStatement)
          && getLexer().isNot(AsmToken::Comma))
     Parser.Lex();
-  if (getLexer().isNot(AsmToken::Comma))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::Comma)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
   Parser.Lex();
 
   // Align to word size.
@@ -1412,8 +1414,10 @@ bool PPCAsmParser::ParseDirectiveTC(unsigned Size, SMLoc L) {
 ///  ::= .machine [ cpu | "push" | "pop" ]
 bool PPCAsmParser::ParseDirectiveMachine(SMLoc L) {
   if (getLexer().isNot(AsmToken::Identifier) &&
-      getLexer().isNot(AsmToken::String))
-    return Error(L, "unexpected token in directive");
+      getLexer().isNot(AsmToken::String)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
 
   StringRef CPU = Parser.getTok().getIdentifier();
   Parser.Lex();
@@ -1423,11 +1427,15 @@ bool PPCAsmParser::ParseDirectiveMachine(SMLoc L) {
   // Implement ".machine any" (by doing nothing) for the benefit
   // of existing assembler code.  Likewise, we can then implement
   // ".machine push" and ".machine pop" as no-op.
-  if (CPU != "any" && CPU != "push" && CPU != "pop")
-    return Error(L, "unrecognized machine type");
+  if (CPU != "any" && CPU != "push" && CPU != "pop") {
+    Error(L, "unrecognized machine type");
+    return false;
+  }
 
-  if (getLexer().isNot(AsmToken::EndOfStatement))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
 
   return false;
 }
@@ -1436,8 +1444,10 @@ bool PPCAsmParser::ParseDirectiveMachine(SMLoc L) {
 ///  ::= .machine cpu-identifier
 bool PPCAsmParser::ParseDarwinDirectiveMachine(SMLoc L) {
   if (getLexer().isNot(AsmToken::Identifier) &&
-      getLexer().isNot(AsmToken::String))
-    return Error(L, "unexpected token in directive");
+      getLexer().isNot(AsmToken::String)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
 
   StringRef CPU = Parser.getTok().getIdentifier();
   Parser.Lex();
@@ -1445,16 +1455,24 @@ bool PPCAsmParser::ParseDarwinDirectiveMachine(SMLoc L) {
   // FIXME: this is only the 'default' set of cpu variants.
   // However we don't act on this information at present, this is simply
   // allowing parsing to proceed with minimal sanity checking.
-  if (CPU != "ppc7400" && CPU != "ppc" && CPU != "ppc64")
-    return Error(L, "unrecognized cpu type");
+  if (CPU != "ppc7400" && CPU != "ppc" && CPU != "ppc64") {
+    Error(L, "unrecognized cpu type");
+    return false;
+  }
 
-  if (isPPC64() && (CPU == "ppc7400" || CPU == "ppc"))
-    return Error(L, "wrong cpu type specified for 64bit");
-  if (!isPPC64() && CPU == "ppc64")
-    return Error(L, "wrong cpu type specified for 32bit");
+  if (isPPC64() && (CPU == "ppc7400" || CPU == "ppc")) {
+    Error(L, "wrong cpu type specified for 64bit");
+    return false;
+  }
+  if (!isPPC64() && CPU == "ppc64") {
+    Error(L, "wrong cpu type specified for 32bit");
+    return false;
+  }
 
-  if (getLexer().isNot(AsmToken::EndOfStatement))
-    return Error(L, "unexpected token in directive");
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    Error(L, "unexpected token in directive");
+    return false;
+  }
 
   return false;
 }
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 3ed20d99f5..cbddec42cb 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -2693,11 +2693,9 @@ bool X86AsmParser::ParseDirective(AsmToken DirectiveID) {
   } else if (IDVal.startswith(".intel_syntax")) {
     getParser().setAssemblerDialect(1);
     if (getLexer().isNot(AsmToken::EndOfStatement)) {
-      if(Parser.getTok().getString() == "noprefix") {
-        // FIXME : Handle noprefix
+      // FIXME: Handle noprefix
+      if (Parser.getTok().getString() == "noprefix")
         Parser.Lex();
-      } else
-        return true;
     }
     return false;
   }
@@ -2711,7 +2709,7 @@ bool X86AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
     for (;;) {
       const MCExpr *Value;
       if (getParser().parseExpression(Value))
-        return true;
+        return false;
 
       getParser().getStreamer().EmitValue(Value, Size);
 
@@ -2719,8 +2717,10 @@ bool X86AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
         break;
 
       // FIXME: Improve diagnostic.
-      if (getLexer().isNot(AsmToken::Comma))
-        return Error(L, "unexpected token in directive");
+      if (getLexer().isNot(AsmToken::Comma)) {
+        Error(L, "unexpected token in directive");
+        return false;
+      }
       Parser.Lex();
     }
   }
@@ -2738,7 +2738,7 @@ bool X86AsmParser::ParseDirectiveCode(StringRef IDVal, SMLoc L) {
       SwitchMode(X86::Mode16Bit);
       getParser().getStreamer().EmitAssemblerFlag(MCAF_Code16);
     }
-  } else  if (IDVal == ".code32") {
+  } else if (IDVal == ".code32") {
     Parser.Lex();
     if (!is32BitMode()) {
       SwitchMode(X86::Mode32Bit);
@@ -2751,7 +2751,8 @@ bool X86AsmParser::ParseDirectiveCode(StringRef IDVal, SMLoc L) {
       getParser().getStreamer().EmitAssemblerFlag(MCAF_Code64);
     }
   } else {
-    return Error(L, "unexpected directive " + IDVal);
+    Error(L, "unknown directive " + IDVal);
+    return false;
   }
 
   return false;
diff --git a/test/MC/X86/x86-target-directives.s b/test/MC/X86/x86-target-directives.s
new file mode 100644
index 0000000000..b6c7e78406
--- /dev/null
+++ b/test/MC/X86/x86-target-directives.s
@@ -0,0 +1,7 @@
+# RUN: not llvm-mc -triple i386 -filetype asm -o - %s 2>&1 | FileCheck %s
+
+	.code42
+
+# CHECK: unknown directive .code42
+# CHECK-NOT: unknown directive
+