[glibc/azanella/clang] elf: Supress clang -Wsometimes-uninitialized on _dl_debug_initialize

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=2542d3ad1594dcac24a2e31aab21cc22ce4f2501

commit 2542d3ad1594dcac24a2e31aab21cc22ce4f2501
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Wed Aug 24 12:25:05 2022 -0300

    elf: Supress clang -Wsometimes-uninitialized on _dl_debug_initialize
    
    Clang issues an warning where variable 'r' is used uninitialized
    whenever 'if' condition is false.  The _dl_debug_initialize is called
    for static case always with LM_ID_BASE (csu/libc-start.c and
    elf/dl-reloc-static-pie.c) and DL_NSS will be always larger than 1
    for shared case.

Diff:
---
 elf/dl-debug.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/elf/dl-debug.c b/elf/dl-debug.c
index 538468dc0b..74aabeed0d 100644
--- a/elf/dl-debug.c
+++ b/elf/dl-debug.c
@@ -54,7 +54,15 @@ _dl_debug_update (Lmid_t ns)
 struct r_debug *
 _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
 {
-  struct r_debug_extended *r, **pp = NULL;
+  /* clang issues an warning where variable 'r' is used uninitialized whenever
+     'if' condition is false.  The _dl_debug_initialize is called for static
+     case always with LM_ID_BASE (csu/libc-start.c and
+     elf/dl-reloc-static-pie.c) and DL_NSS will be always larger than 1 for
+     shared case.  */
+  DIAG_PUSH_NEEDS_COMMENT_CLANG;
+  DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wsometimes-uninitialized");
+  struct r_debug_extended *r;
+  struct r_debug_extended **pp = NULL;
 
   if (ns == LM_ID_BASE)
     {
@@ -81,6 +89,7 @@ _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
 	  r->base.r_version = 2;
 	}
     }
+  DIAG_POP_NEEDS_COMMENT_CLANG;
 
   if (r->base.r_brk == 0)
     {