[gcc r12-8055] libgcc: IA64: don't compile glibc-based unwinder without libc headers

[gcc r12-8055] libgcc: IA64: don't compile glibc-based unwinder without libc headers

[Sergei Trofimovich]

https://gcc.gnu.org/g:cef03728234644b1a9ad5bd8e94daeac8650a71b

commit r12-8055-gcef03728234644b1a9ad5bd8e94daeac8650a71b
Author: Sergei Trofimovich <siarheit@google.com>
Date:   Thu Apr 7 08:36:23 2022 +0100

    libgcc: IA64: don't compile glibc-based unwinder without libc headers
    
    In --without-headers mode gcc fails to bootstrap on libgcc as:
    
        /build/build/./gcc/xgcc -B/build/build/./gcc/ ... -Dinhibit_libc -c fde-glibc.c
        ../../../gcc-12-20220403/libgcc/config/ia64/fde-glibc.c:33:10:
            fatal error: stdlib.h: No such file or directory
    
    Most other linux targets are able to build the --without-headers
    compiler without additional effort. This change adds IA64 to the fold.
    
    The change drops part of the code that relies on DYNAMIC glibc
    section traversal for backtraces.
    
    Tested bootstrap of ia64-unknown-linux-gnu with and without libc
    headers present.
    
    libgcc/
            * config/ia64/fde-glibc.c: Make a no-op in inhibit_libc mode.

Diff:
---
 libgcc/config/ia64/fde-glibc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libgcc/config/ia64/fde-glibc.c b/libgcc/config/ia64/fde-glibc.c
index 9caac2bca24..bd74847fa85 100644
--- a/libgcc/config/ia64/fde-glibc.c
+++ b/libgcc/config/ia64/fde-glibc.c
@@ -29,6 +29,7 @@
 #define _GNU_SOURCE 1
 #endif
 #include "config.h"
+#ifndef inhibit_libc
 #include <stddef.h>
 #include <stdlib.h>
 #include <link.h>
@@ -159,3 +160,4 @@ _Unwind_FindTableEntry (void *pc, unw_word *segment_base, unw_word *gp,
 
   return data.ret;
 }
+#endif