824633 - clang++ chokes on bignum-dtoa.cc on powerpc

Status: RESOLVED INVALID

(Core :: MFBT, defect)

Description

[Landry Breuil (:gaston)]

Attachment: bignum-dtoa assembly file

Pretty sure that's an llvm/clang bug, but filing here for tracking purposes. mozilla-central builds fine with clang 3.1 & clang 3.2 on OpenBSD/amd64/i386 but fails on OpenBSD/powerpc (32), on bignum-dtoa.cc. the generated assembly contains .loc lines with 'prologue_end' at the end, and apparently this is the issue.

bignum-dtoa.s: Assembler messages:
bignum-dtoa.s:55: Error: junk at end of line, first unrecognized character is `p'
bignum-dtoa.s:362: Warning: setting incorrect section attributes for .text._ZN17double_conversion6Sing
leC1Ef
bignum-dtoa.s:388: Error: junk at end of line, first unrecognized character is `p'
bignum-dtoa.s:408: Warning: setting incorrect section attributes for .text._ZNK17double_conversion6Sin
gle11SignificandEv
....
....
mfbt/bignum-dtoa.s:3003: Error: unknown pseudo-op: `.cfi_sections'

This of course with our ancient as 2.15:
$as -v
GNU assembler version 2.15 (powerpc-unknown-openbsd5.2) using BFD version 2.15

removing the 'prologue_end' part still lefts the 'unknown pseudo-op .cfi_sections' error.

I've found llvm bug http://llvm.org/bugs/show_bug.cgi?id=11867 to look related, and i've tried with & without the following chunk (poke compiler with random sticks..) :

--- tools/clang/lib/Basic/Targets.cpp.orig      Tue Dec 25 10:48:34 2012
+++ tools/clang/lib/Basic/Targets.cpp   Tue Dec 25 10:49:14 2012
@@ -1025,6 +1025,7 @@ class PPC32TargetInfo : public PPCTargetInfo { (public
     case llvm::Triple::Linux:
     case llvm::Triple::FreeBSD:
     case llvm::Triple::NetBSD:
+    case llvm::Triple::OpenBSD:
       SizeType = UnsignedInt;
       PtrDiffType = SignedInt;
       IntPtrType = SignedInt;

That didnt help.

Anyone tried building m-c on linux/ppc with clang ?

Comment 1

[Rafael Ávila de Espíndola (:espindola) (not reading bugmail)]

llvm.org/pr11867 looks unrelated.  I would suggest reporting a bug in llvm with a preprocessed source file where clang produces an assembly with prologue_end and gcc does not.

What assembler are you trying to use? gas supports . cfi_* for quiet some time now. If the one on openbsd doesn't support that, please open another bug about disabling it.

Comment 2

[Brad Smith]

These are issues with LLVM and nothing to do Firefox. This bug report can be closed.

Comment 3

[Landry Breuil (:gaston)]

(In reply to brad from comment #2)
> These are issues with LLVM and nothing to do Firefox. This bug report can be
> closed.

Then i'll close it when i'm able to build mozilla-central with clang on powerpc. In the meantime it's a tracking bug.

Comment 4

[Simon Giesecke [:sg] [he/him]]

I think after 8 years this can be closed. If there's still an issue with a current clang/LLVM version, please reopen.