code review 13248046: go.tools/addr2line: Fix compatibility with external lin...

libmach: accept OS X binary generated by external linker

Fixes cpu subtype check when using external linker which sets the CPU_SUBTYPE_LIB64 bit (1<<31).
Fixes issue 6197.

[stacktic, 2013-09-07 15:45:18]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[minux1, 2013-09-07 19:38:27]

https://codereview.appspot.com/13248046/diff/6001/src/libmach/executable.c
File src/libmach/executable.c (right):

https://codereview.appspot.com/13248046/diff/6001/src/libmach/executable.c#ne...
src/libmach/executable.c:1079: if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86 &&
mp->cpusubtype != MACH_CPU_SUBTYPE_X86_64) {
i'm wondering if we should write this:
if ((mp->cpusubtype & ~CPU_SUBTYPE_MASK) != MACH_CPU_SUBTYPE_X86)

to be future-extension proof.

[rsc, 2013-09-09 19:50:38]

LGTM

Please complete a CLA as described at golang.org/doc/contribute.html#copyright

[rsc, 2013-09-09 19:51:00]

Also please change the first line of the description to

libmach: accept OS X binary generated by external linker

There is no "go.tools/addr2line".

[bradfitz, 2013-09-10 18:50:34]

*** Submitted as https://code.google.com/p/go/source/detail?r=f22ec517eda6 ***

libmach: accept OS X binary generated by external linker

Fixes cpu subtype check when using external linker which sets the
CPU_SUBTYPE_LIB64 bit (1<<31).
Fixes issue 6197.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://codereview.appspot.com/13248046

Committer: Brad Fitzpatrick <bradfitz@golang.org>