Re: [ada, patch] fix libgnat build on x86_64-linux-gnux32 with glibc <= 2.31

[Arnaud Charlet <charlet@adacore.com>]

> This was introduced with the fix and backports of PR103530 on
> x86_64-linux-gnux32 with older glibc versions (checked with 2.31), where
> dladdr is still in the libdl.so library, and not included in libc.so as in
> newer glibc versions.
> Linking of libgnat.so fails with
> 
> [...]
> /usr/x86_64-linux-gnux32/bin/ld: s-trasym.o: in function
> `system__traceback__symbolic__module_na
> me__getXnn':
> collect2: error: ld returned 1 exit status
> make[8]: *** [gcc-interface/Makefile:677: gnatlib-shared-default] Error 1
> 
> https://gcc.gnu.org/git/?p=gcc.git;a=patch;h=9d6c63ba490ec92245f04b5cbafc56abd28e8d22
> 
> -- a/gcc/ada/Makefile.rtl
> +++ b/gcc/ada/Makefile.rtl
> @@ -2650,13 +2650,18 @@ ifeq ($(strip $(filter-out %x32 linux%,$(target_cpu)
> $(target_os))),)
>    s-tasinf.adb<libgnarl/s-tasinf__linux.adb \
>    s-tpopsp.adb<libgnarl/s-tpopsp__tls.adb \
>    s-taspri.ads<libgnarl/s-taspri__posix.ads \
> +  $(TRASYM_DWARF_UNIX_PAIRS) \
> +  s-tsmona.adb<libgnat/s-tsmona__linux.adb \
>    $(ATOMICS_TARGET_PAIRS) \
>    $(X86_64_TARGET_PAIRS) \
> +  $(GNATRTL_128BIT_PAIRS) \
>    system.ads<libgnat/system-linux-x86.ads
> 
> The addition of s-tsmona.adb<libgnat/s-tsmona__linux.adb pulls in the
> reference to dladdr, however not setting MISCLIB to -ldl as on other
> architectures
> 
> Proposed patch:
> 
> 
>  PR ada/107475
>  * Makefile.rtl: Set MISCLIB for x86_64-linux-gnux32.
> 
> 
> --- a/gcc/ada/Makefile.rtl
> +++ b/gcc/ada/Makefile.rtl
> @@ -2584,6 +2584,7 @@ ifeq ($(strip $(filter-out %x32 linux%,$(target_cpu)
> $(target_os))),)
>    EXTRA_GNATRTL_TASKING_OBJS=s-linux.o a-exetim.o
>    EH_MECHANISM=-gcc
>    THREADSLIB=-lpthread -lrt
> +  MISCLIB = -ldl
>    GNATLIB_SHARED=gnatlib-shared-dual
>    GMEM_LIB = gmemlib
>    LIBRARY_VERSION := $(LIB_VERSION)
> 
> Ok for the trunk and the branches?

Yes, thanks.