This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
[PATCH 3/3] 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: Sun, 30 Sep 2018 15:53:55 +0000
- Subject: [PATCH 3/3] locale: prevent maybe-uninitialized errors with -Os [BZ #19444]
- References: <alpine.DEB.2.21.1809191323000.14910@digraph.polyomino.org.uk>
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 #23716]
* locale/weight.h: Fix build with -Os.
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
---
ChangeLog | 4 ++++
locale/weight.h | 7 +++++++
2 files changed, 11 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index 9cdf59c9ab..ef506309aa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2018-09-30 Martin Jansa <Martin.Jansa@gmail.com>
+ Partial fix for [BZ #23716]
+ * locale/weight.h: Fix build with -Os.
+
2018-09-30 Martin Jansa <Martin.Jansa@gmail.com>
Partial fix for [BZ #23716]
* sysdeps/ieee754/soft-fp/s_fdiv.c: Fix build with -O.
diff --git a/locale/weight.h b/locale/weight.h
index 6028d3595e..10bcea25e5 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