call to stdcall-named function causes AsmParser to choke

[llvmbot]

Bugzilla Link	9067
Version	trunk
OS	Windows XP
Reporter	LLVM Bugzilla Contributor

Extended Description

Hello,
Recently there has been revision 114154 - MC/AsmParser: Add support for 'a + 4@GOTPCREL' added to the trunk. The submitted patch adds check whether @ suffix is one of list of predefined ones (done in lib/MC/MCParser/AsmParser.cpp around line 512).

Code (reformated for bugzilla) goes like this:
MCSymbol *Sym = getContext().GetOrCreateSymbol(Split.first);
...
MCSymbolRefExpr::VariantKind Variant =
MCSymbolRefExpr::getVariantKindForName(Split.second);
if (Variant == MCSymbolRefExpr::VK_Invalid)
{
Variant = MCSymbolRefExpr::VK_None;
return TokError("invalid variant '" + Split.second + "'");
}
....

Problem is when stdcall function on wincoff gets called from assembly with similar assembly line: calll *_GetTickCount@0, the '0' after '@' will obviously cause VK_Invalid to be set on Variant, user gets:
... invalid variant '0'.

I propose to add a reference to MCAsmInfo to AsmParser, initialize it in constructor and add check for MAI.hasMicrosoftFastStdCallMangling() to AsmParser::ParsePrimaryExpr, then call GetOrCreateSymbol on whole Identifier without splitting it around '@' for wincoff case.

I can send patch for revision in around 10 hours. I can then try to support with extensions for cc1as for Wincoff (1 .section doesnt get parsed, 2 zerofill from coffasmparser causes llvm_unreachable).

What do You guys think of proposed change?

Regards,

[llvmbot]

Hello, not sure if thats the right place to post, but I finally prepared tiny little patch, that makes AsmParser accept again the identifiers following stdcall convention i.e. __imp__EnterCriticalSection@4 (wincoff based). Hopefully this one will work better than my first attempt at contributing to this great project from some late 2007. Please start a review or suggest a better place to start things going.

At later time, I might provide a tiny testcase that will prove, pre-114154 versions accepted those identifiers, 114154 till this one dont, and after my patch its accepted again.

All the best,

[llvmbot]

patch to fix AsmParser not accepting stdcall-based identifiers

[lattner]

Hi Pawel,

Please send patches to llvm-commits. People often miss them when filed as bugs.