[PATCH] AsmParser: add support for .end directive

[David Peixotto]

Hi Saleem,

Thank you for implementing support for this directive. I think it is nice to have for completness with gas. 

My main question is how does this directive interact with .include'd files. If we have .end in a file that is being processed because of a .include will it stop processing everything, or only that file. I think gas will stop processing everything, even the original file.

Please add a test case that shows the behavior to expect when processing a .end directive in a .include file. I think it is ok to follow what gas does here.

-David


> -----Original Message-----
> From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-
> bounces at cs.uiuc.edu] On Behalf Of Saleem Abdulrasool
> Sent: Sunday, December 15, 2013 7:28 PM
> To: compnerd at compnerd.org
> Cc: llvm-commits at cs.uiuc.edu
> Subject: Re: [PATCH] AsmParser: add support for .end directive
> 
>   Fix for target specific handling of end directive (e.g. MIPS).
> 
> http://llvm-reviews.chandlerc.com/D2414
> 
> CHANGE SINCE LAST DIFF
>   http://llvm-reviews.chandlerc.com/D2414?vs=6109&id=6112#toc
> 
> Files:
>   lib/MC/MCParser/AsmParser.cpp
>   test/MC/AsmParser/directive_end.s
> 
> Index: lib/MC/MCParser/AsmParser.cpp
> ===================================================================
> --- lib/MC/MCParser/AsmParser.cpp
> +++ lib/MC/MCParser/AsmParser.cpp
> @@ -358,7 +358,8 @@
>      DK_CFI_RESTORE, DK_CFI_ESCAPE, DK_CFI_SIGNAL_FRAME, DK_CFI_UNDEFINED,
>      DK_CFI_REGISTER, DK_CFI_WINDOW_SAVE,
>      DK_MACROS_ON, DK_MACROS_OFF, DK_MACRO, DK_ENDM, DK_ENDMACRO,
> DK_PURGEM,
> -    DK_SLEB128, DK_ULEB128
> +    DK_SLEB128, DK_ULEB128,
> +    DK_END
>    };
> 
>    /// \brief Maps directive name --> DirectiveKind enum, for @@ -464,6
> +465,9 @@
>    // "align"
>    bool parseDirectiveMSAlign(SMLoc DirectiveLoc, ParseStatementInfo
> &Info);
> 
> +  // "end"
> +  bool parseDirectiveEnd(SMLoc DirectiveLoc);
> +
>    void initializeDirectiveKindMap();
>  };
>  }
> @@ -1516,6 +1520,8 @@
>        return parseDirectiveEndMacro(IDVal);
>      case DK_PURGEM:
>        return parseDirectivePurgeMacro(IDLoc);
> +    case DK_END:
> +      return parseDirectiveEnd(IDLoc);
>      }
> 
>      return Error(IDLoc, "unknown directive"); @@ -3751,6 +3757,20 @@
>    return false;
>  }
> 
> +/// parseDirectiveEnd
> +/// ::= .end
> +bool AsmParser::parseDirectiveEnd(SMLoc DirectiveLoc) {
> +  if (getLexer().isNot(AsmToken::EndOfStatement))
> +    return TokError("unexpected token in '.end' directive");
> +
> +  Lex();
> +
> +  while (Lexer.isNot(AsmToken::Eof))
> +    Lex();
> +
> +  return false;
> +}
> +
>  /// parseDirectiveEndIf
>  /// ::= .endif
>  bool AsmParser::parseDirectiveEndIf(SMLoc DirectiveLoc) { @@ -3836,6
> +3856,7 @@
>    DirectiveKindMap[".ifnotdef"] = DK_IFNOTDEF;
>    DirectiveKindMap[".elseif"] = DK_ELSEIF;
>    DirectiveKindMap[".else"] = DK_ELSE;
> +  DirectiveKindMap[".end"] = DK_END;
>    DirectiveKindMap[".endif"] = DK_ENDIF;
>    DirectiveKindMap[".skip"] = DK_SKIP;
>    DirectiveKindMap[".space"] = DK_SPACE;
> Index: test/MC/AsmParser/directive_end.s
> ===================================================================
> --- /dev/null
> +++ test/MC/AsmParser/directive_end.s
> @@ -0,0 +1,11 @@
> +# RUN: llvm-mc -triple i386-unknown-unknown %s -filetype obj -o - \
> +# RUN:   | llvm-readobj -t | FileCheck %s
> +
> +	.end
> +
> +its_a_tarp:
> +	int $0x3
> +
> +# CHECK: Symbol {
> +# CHECK-NOT:   Name: its_a_tarp
> +