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From: Yang Yanchao <yangyanchao6@huawei.com>
To: <libc-alpha@sourceware.org>
Cc: <linfeilong@huawei.com>, <fweimer@redhat.com>, <schwab@linux-m68k.org>
Subject: [PATCH v3] elf: fixes compile error when both enable -Werror and -DNDEBUG
Date: Sat, 2 Apr 2022 17:51:52 +0800	[thread overview]
Message-ID: <20220402095152.3063-1-yangyanchao6@huawei.com> (raw)

Use -Werror and -DNDEBUG at the same time will
causes the following compilation errors:

cache.c: In function 'save_cache':
cache.c:758:15: error: unused variable 'old_offset' [-Werror=unused-variable]
  758 |       off64_t old_offset = lseek64 (fd, extension_offset, SEEK_SET);
      |               ^~~~~~~~~~

-DNDEBUG will disables the assertion.
Therefore, only the variables used by assertions do not take effect.
Fooling the Compiler with Type Conversions.
---
 elf/cache.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/elf/cache.c b/elf/cache.c
index dbf4c83a7a..68cd4d0828 100644
--- a/elf/cache.c
+++ b/elf/cache.c
@@ -754,6 +754,7 @@ save_cache (const char *cache_name)
     {
       /* Align file position to 4.  */
       off64_t old_offset = lseek64 (fd, extension_offset, SEEK_SET);
+      (void) old_offset;
       assert ((unsigned long long int) (extension_offset - old_offset) < 4);
       write_extensions (fd, str_offset, extension_offset);
     }
-- 
2.33.0


             reply	other threads:[~2022-04-02  9:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-02  9:51 Yang Yanchao [this message]
2022-04-11 14:29 ` Carlos O'Donell

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