[PATCH] Use a non-empty test program to test ability to link

[Sandra Loosemore]

On 2/7/20 3:24 PM, Joseph Myers wrote:
> On Wed, 5 Feb 2020, Sandra Loosemore wrote:
> 
>> This patch is for PR 79193 and 88999, problems where libstdc++ is
>> mis-configuring itself when building for a bare-metal target because it thinks
>> it can link programs without pulling in the BSP that provides low-level I/O
>> support.  (Specifically, this was observed on nios2-elf with Newlib and GDB
>> semihosting.)  It'll build just fine if it recognizes that it can only compile
>> programs and not link them, but it's confused because using an empty program
>> to test for ability to link succeeds.
>>
>> Is this configure change OK, and suitable for stage 4?
>>
>> BTW, I did run autoconf in every subdirectory that contains a configure.ac,
>> but it appears only libstc++-v3 actually uses this test; all the other
>> regenerated configure scripts were unchanged.
> 
> There's some problem with that regeneration, then; every directory where
> configure.ac mentions GCC_NO_EXECUTABLES should have a resulting change (I
> tested regenerating in libgcc/ with this patch applied and got such a
> change, for example).

Hmmm.  I just tried that again and got nothing.  Do I have to do 
something other than just run "autoconf" in that directory?  I'm always 
confused by anything involving configuration changes.  :-(

-Sandra