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[PATCH] locale: prevent maybe-uninitialized errors with -Os [BZ #19444]
- From: Martin Jansa <martin dot jansa at gmail dot com>
- To: libc-alpha at sourceware dot org
- Cc: Martin Jansa <Martin dot Jansa at gmail dot com>
- Date: Wed, 27 Feb 2019 22:31:40 +0000
- Subject: [PATCH] locale: prevent maybe-uninitialized errors with -Os [BZ #19444]
Fixes following error when building for aarch64 with -Os:
| In file included from strcoll_l.c:43:
| strcoll_l.c: In function '__strcoll_l':
| ../locale/weight.h:31:26: error: 'seq2.back_us' may be used uninitialized in this function [-Werror=maybe-uninitialized]
| int_fast32_t i = table[*(*cpp)++];
| ^~~~~~~~~
| strcoll_l.c:304:18: note: 'seq2.back_us' was declared here
| coll_seq seq1, seq2;
| ^~~~
| In file included from strcoll_l.c:43:
| ../locale/weight.h:31:26: error: 'seq1.back_us' may be used uninitialized in this function [-Werror=maybe-uninitialized]
| int_fast32_t i = table[*(*cpp)++];
| ^~~~~~~~~
| strcoll_l.c:304:12: note: 'seq1.back_us' was declared here
| coll_seq seq1, seq2;
| ^~~~
Partial fix for [BZ #19444]
* locale/weight.h: Fix build with -Os.
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
---
ChangeLog | 5 +++++
locale/weight.h | 7 +++++++
2 files changed, 12 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index ed05044fe8..f08196da7e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-28 Martin Jansa <Martin.Jansa@gmail.com>
+
+ Partial fix for [BZ #19444]
+ * locale/weight.h: Fix build with -Os.
+
2019-02-27 H.J. Lu <hongjiu.lu@intel.com>
* configure.ac (have-ifunc): New LIBC_CONFIG_VAR.
diff --git a/locale/weight.h b/locale/weight.h
index 7ca81498b2..d608ca70bb 100644
--- a/locale/weight.h
+++ b/locale/weight.h
@@ -28,7 +28,14 @@ findidx (const int32_t *table,
const unsigned char *extra,
const unsigned char **cpp, size_t len)
{
+ /* With GCC 8 when compiling with -Os the compiler warns that
+ seq1.back_us and seq2.back_us might be used uninitialized.
+ This uninitialized use is impossible for the same reason
+ as described in comments in locale/weightwc.h. */
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_Os_NEEDS_COMMENT (8, "-Wmaybe-uninitialized");
int_fast32_t i = table[*(*cpp)++];
+ DIAG_POP_NEEDS_COMMENT;
const unsigned char *cp;
const unsigned char *usrc;
--
2.17.1