patchGNU Autoconf Archive - Patches: patch #8515, AX_GCC_ARCHFLAG: reorder option...


patch #8515: AX_GCC_ARCHFLAG: reorder option checking for Clang

Submitter:  Tsukasa OI <a4lg>
Submitted:  Fri 15 Aug 2014 09:51:01 AM UTC
Priority:  5 - Normal Status:  Done
Assigned to:  simons Open/Closed:  Closed
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Wed 15 Oct 2014 09:10:10 AM UTC, comment #2: 

I pushed your patches in 7354d36 and 570de78. Thank you very much!

Peter Simons <simons>
Group administrator
Mon 25 Aug 2014 04:40:31 AM UTC, comment #1: 

Added a workaround for Clang compiler.


We need support for C++. For various language support, requiring AC_PROG_CC in this macro may be inappropriate. But we have to check first whether removing this AC_REQUIRE causes issues before we do so.

(file #31957)

Tsukasa OI <a4lg>
Fri 15 Aug 2014 09:51:01 AM UTC, original submission:

As I mentioned in the submission above, LLVM Clang support on this macro is partially corrupt because of different error handling from GCC.

For instance, in my Ivy Bridge environment with Clang compiler,

  • AX_GCC_ARCHFLAG([no]) selects option `-mcpu=ivybridge' which is not really supported by LLVM Clang
  • AX_GCC_ARCHFLAG([yes]) selects option `-mtune=ivybridge' which is not really support by LLVM Clang (as well)

This is because Clang does not fail on unknown processor type specified in -mcpu=... and -mtune=... options. This fix (changes order of option checking) does not resolve all the problems (AX_GCC_ARCHFLAG([yes]) still selects `-mtune=ivybridge') but it will solve some of them.

Please note that the submitted patch is expected to be applied after the patch #8514 but you could apply this patch first (with small modifications).

Tsukasa OI <a4lg>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

Attached Files
file #31957:  0002-AX_GCC_ARCHFLAG-add-workaround-for-Clang.patch added by a4lg (2KiB - application/octet-stream - version 1 patchset patch 2 (after file #31904), Clang workaround)


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  • -email is unavailable- added by simons (Posted a comment)
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    Follow 7 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2014-10-16 simons StatusReady For Test Done
        Open/ClosedOpen Closed
    2014-10-15 simons StatusNone Ready For Test
        Assigned toNone simons
        Carbon-Copy- Added steven g. johnson <>
    2014-08-25 a4lg Attached File- Added 0002-AX_GCC_ARCHFLAG-add-workaround-for-Clang.patch, #31957
    2014-08-15 a4lg Attached File- Added 0001-AX_GCC_ARCHFLAG-reorder-option-checking-for-Clang.patch, #31904

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