Re: AC_TRY_COMPILE() annoyances with 2.63b

[Eric Blake]

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According to Mike Frysinger on 4/14/2009 8:11 PM:
> well, is there any real need to preserve the exit value of the if statement ? 
>  
> in other words, past implementations of autoconf didnt preserve it and it 
> isnt 
> like anyone complained.  the old generated code:

for AC_TRY_COMPILE, but not for other clients of AS_IF

> .......
> else
>   echo "$as_me: failed program was:" >&5
> sed 's/^/| /' conftest.$ac_ext >&5
> 
>       <stuff from user 4th arg -- $? is now set to exit value of `sed`, not 
> the if>

The AC_RUN_IFELSE test in the testsuite if a valid test that showed
someone caring about the exit status:

AC_RUN_IFELSE([AC_LANG_PROGRAM([], [return 2])],
              [AC_MSG_ERROR([saw `return 2' as a success])],
              [estatus=$?
test $estatus != 2 &&
  AC_MSG_ERROR([did not get as 2 exit status: $estatus])])

When running a test program, you really can care about $?, more than just
the fact that you hit the else branch of the AS_IF.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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