Unexpected error: LLVM ERROR: expected relocatable expression

[llvmbot]

Bugzilla Link	16176
Version	trunk
OS	Linux
Attachments	2 tests a.s and d.s both show the same error.
Reporter	LLVM Bugzilla Contributor

Extended Description

foo:
.word -foo

The above should be legal but I get a
LLVM ERROR: expected relocatable expression when using:

llvm-mc -filetype=obj

This is another example and generates the same error:

.Ltmp3:
.Ltmp5:
.Ltmp13:
.word (.Ltmp5-.Ltmp3)-.Ltmp13

[arsenm]

I see the error on a.s, don't know if it's valid or not. I see no error on d.s

[MaskRay]

Both examples are invalid. An expression that resolves to the negation of a label is usually rejected by gas.

gas reports Error: can't resolve L0 - .Ltmp13 for

.Ltmp3:
.Ltmp5:
.Ltmp13:
.data
.word (.Ltmp5-.Ltmp3)-.Ltmp13

but not when .data is deleted. Seems like a gas bug. LLVM integrated assembler rejects both cases as intended.