Clang integrated assembler does not handle :vararg macro arguments

[llvmbot]

Bugzilla Link	18919
Resolution	FIXED
Resolved on	Jun 19, 2014 21:46
Version	trunk
OS	Linux
Blocks	#19300
Attachments	example assembly code (ARM).
Reporter	LLVM Bugzilla Contributor
CC	@compnerd,@rengolin

Extended Description

I use an assembly macro like this:
.if cc
\zzz
.endif
.endm

.set cc,1 /* normally something complicated */
...
ifcc sub r12, r5, LSL #​6
bx r12

This way I can stub out several instructions in a routine without needing to cloud the code with lots of conditional assembly. Typically I set cc to some macro parameter to get different variants without excessive copy-paste.

Unfortunately:
% clang --target=arm-linux-gnueabihf -integrated-as ifcc.S
ifcc.S:1:17: error: vararg is not a valid parameter qualifier for 'zzz' in macro 'ifcc'
.macro ifcc zzz:vararg
^
ifcc.S:2:5: error: expected absolute expression
.if cc
^
ifcc.S:3:13: error: unexpected token at start of statement
\zzz
^
ifcc.S:5:6: error: unexpected '.endm' in file, no current macro definition
.endm
^
ifcc.S:12:14: error: unexpected token in argument list
ifcc sub r12, r5, LSL #​6
^

While the GNU assembler sees no problems.

[llvmbot]

I seem to have a cut and paste error, there, completely hiding the point of the bug report. My macro should look like this:

.macro ifcc zzz:vararg
.if cc
        \zzz
.endif
.endm

It's that :vararg that's the problem.

[compnerd]

Fixed in SVN r206951.

[rengolin]

mentioned in issue #19300