[PATCH] configure: check for -march and -mtune passed via CC

[PATCH] configure: check for -march and -mtune passed via CC

[Andre McCurdy]

Some build environments pass -march and -mtune as part of CC, therefore
update configure to check both CC and CFLAGS before making the decision
to fall back to generic -march and -mtune options for x86.

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
---
 configure | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index e35c9b6..f325cda 100755
--- a/configure
+++ b/configure
@@ -391,10 +391,12 @@ tryflag CFLAGS_AUTO -Wa,--noexecstack
 # extensions enabled by default. This is bad for making static binaries.
 # We cheat and use i486 rather than i386 because i386 really does not
 # work anyway (issues with atomic ops).
+# Some build environments pass -march and -mtune options via CC, so
+# check both CC and CFLAGS.
 #
 if test "$ARCH" = "i386" ; then
-fnmatch '-march=*|*\ -march=*' "$CFLAGS" || tryldflag CFLAGS_AUTO -march=i486
-fnmatch '-mtune=*|*\ -mtune=*' "$CFLAGS" || tryldflag CFLAGS_AUTO -mtune=generic
+fnmatch '-march=*|*\ -march=*' "$CC $CFLAGS" || tryldflag CFLAGS_AUTO -march=i486
+fnmatch '-mtune=*|*\ -mtune=*' "$CC $CFLAGS" || tryldflag CFLAGS_AUTO -mtune=generic
 fi
 
 #
-- 
1.9.1

Re: [PATCH] configure: check for -march and -mtune passed via CC

[Rich Felker]

On Tue, Apr 21, 2015 at 10:34:05AM -0700, Andre McCurdy wrote:
> Some build environments pass -march and -mtune as part of CC, therefore
> update configure to check both CC and CFLAGS before making the decision
> to fall back to generic -march and -mtune options for x86.
> 
> Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
> ---
>  configure | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/configure b/configure
> index e35c9b6..f325cda 100755
> --- a/configure
> +++ b/configure
> @@ -391,10 +391,12 @@ tryflag CFLAGS_AUTO -Wa,--noexecstack
>  # extensions enabled by default. This is bad for making static binaries.
>  # We cheat and use i486 rather than i386 because i386 really does not
>  # work anyway (issues with atomic ops).
> +# Some build environments pass -march and -mtune options via CC, so
> +# check both CC and CFLAGS.
>  #
>  if test "$ARCH" = "i386" ; then
> -fnmatch '-march=*|*\ -march=*' "$CFLAGS" || tryldflag CFLAGS_AUTO -march=i486
> -fnmatch '-mtune=*|*\ -mtune=*' "$CFLAGS" || tryldflag CFLAGS_AUTO -mtune=generic
> +fnmatch '-march=*|*\ -march=*' "$CC $CFLAGS" || tryldflag CFLAGS_AUTO -march=i486
> +fnmatch '-mtune=*|*\ -mtune=*' "$CC $CFLAGS" || tryldflag CFLAGS_AUTO -mtune=generic

It's questionable whether we should have this code to begin with, but
as long as we do, I agree the change you proposed is correct. I'll
apply it. Thanks!

Rich