[mc] no support for .macro with arguments

[nlewycky]

Bugzilla Link	9248
Resolution	FIXED
Resolved on	Apr 17, 2016 13:30
Version	unspecified
OS	Linux
Blocks	#4440 llvm/llvm-bugzilla-archive#18918
CC	@compnerd,@edwintorok,@kjwinchester

Extended Description

llvm-mc rejects this file:

.macro macroname argone argtwo
.endm

with:

$ llvm-mc -assemble -filetype=obj y.s
y.s:1:19: error: unexpected token in '.macro' directive
.macro macroname argone argtwo
^
y.s:2:7: error: unexpected '.endm' in file, no current macro definition
.endm
^

while as is fine with it. The unknown tokens are arguments to the macro, documented in GAS here: http://sourceware.org/binutils/docs-2.21/as/Macro.html

This is blocking arch/x86/include/asm/inst.h in the linux kernel.

[edwintorok]

Needs:

• new token for \ in asmlexer
• parse macro argument names
• handle arguments with default values
• handle non-blank arguments (:req)
• support () in macro body

GAS also supports :vararg, and .altmacro but that doesn't seem to be required for the kernel.

[llvmbot]

I am implementing this (maybe just a subset).

[llvmbot]

I implemented the basics in 132656, but don't intend to implement the rest right now.

[compnerd]

Im going to close this off as the list that is mentioned is pretty out of date. The only feature from that list which is currently unsupported is the alternate mode assembly input.