On 2023-05-23 09:46, Bruno Haible wrote:
The diffutils CI reports a build failure:
CC diff.o
../../../sources/diffutils/src/diff.c: In function 'compare_files':
../../../sources/diffutils/src/diff.c:1209:8: error: missing initializer for
field 'name' of 'struct file_data' [-Werror=missing-field-initializers]
I don't know how to find out the details of the diffutils CI build.
However, I think the bug is probably that the build was using GCC 11.1
or 11.2, which is buggy in this area. I installed the attached patches
to Gnulib to work around that problem.
If you're configuring with --enable-gcc-warnings or equivalent, it's
better to use current GCC. Older versions of GCC have several problems
in this area, and although I went to the trouble of working around this
particular problem I doubt whether it's worth our time to worry about
all false positives generated by older GCC versions, so it might be
better to build with --disable-gcc-warnings on older platforms.From 46a4745434bb3620f5c67df29969fe8bd311870c Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Wed, 24 May 2023 09:20:48 -0700
Subject: [PATCH 1/3] manywarnings: port better to GCC 11.2 and earlier
Problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-diffutils/2023-05/msg00015.html
* m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC):
Also test for GCC bug 82283
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82283>.
---
ChangeLog | 9 +++++++++
m4/manywarnings.m4 | 7 +++++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 01944021be..81057be3d6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2023-05-24 Paul Eggert <egg...@cs.ucla.edu>
+
+ manywarnings: port better to GCC 11.2 and earlier
+ Problem reported by Bruno Haible in:
+ https://lists.gnu.org/r/bug-diffutils/2023-05/msg00015.html
+ * m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC):
+ Also test for GCC bug 82283
+ <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82283>.
+
2023-05-24 Bruno Haible <br...@clisp.org>
asyncsafe-spin, simple-atomic: Don't use -mcpu-v9 on NetBSD/sparc.
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 13db996516..77b96295df 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -69,11 +69,14 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
CFLAGS="$CFLAGS -Wextra -Werror"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
- [[int f (void)
+ [[struct file_data { int desc, name; };
+ struct cmp { struct file_data file[1]; };
+ void f (struct cmp *r)
{
typedef struct { int a; int b; } s_t;
s_t s1 = { 0, };
- return s1.b;
+ struct cmp cmp = { .file[0].desc = r->file[0].desc + s1.a };
+ *r = cmp;
}
]],
[[]])],
--
2.39.2
From b00ffa282f3c494012a127919f8625e14d89f80d Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Wed, 24 May 2023 09:23:01 -0700
Subject: [PATCH 2/3] Simplify -Wno-missing-field-initializers checking
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
* m4/gnulib-common.m4 (gl_CC_GNULIB_WARNINGS): Don’t worry about
-Wmissing-field-initializers, as this is no longer needed now that
gl_MANYWARN_ALL_GCC is fixed.
---
ChangeLog | 5 +++++
m4/gnulib-common.m4 | 4 ----
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 81057be3d6..e09a981eec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
2023-05-24 Paul Eggert <egg...@cs.ucla.edu>
+ Simplify -Wno-missing-field-initializers checking
+ * m4/gnulib-common.m4 (gl_CC_GNULIB_WARNINGS): Don’t worry about
+ -Wmissing-field-initializers, as this is no longer needed now that
+ gl_MANYWARN_ALL_GCC is fixed.
+
manywarnings: port better to GCC 11.2 and earlier
Problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-diffutils/2023-05/msg00015.html
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index a2b53d33dc..2426eb6398 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1053,7 +1053,6 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
dnl -Wno-float-conversion >= 4.9 >= 3.9
dnl -Wno-float-equal >= 3 >= 3.9
dnl -Wimplicit-fallthrough >= 7 >= 3.9
- dnl -Wno-missing-field-initializers >= 4.0, < 11
dnl -Wno-pedantic >= 4.8 >= 3.9
dnl -Wno-sign-compare >= 3 >= 3.9
dnl -Wno-sign-conversion >= 4.3 >= 3.9
@@ -1079,9 +1078,6 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
#if __GNUC__ >= 7 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
-Wimplicit-fallthrough
#endif
- #if __GNUC__ >= 4 && __GNUC__ < 11 && !defined __clang__
- -Wno-missing-field-initializers
- #endif
#if __GNUC__ + (__GNUC_MINOR__ >= 8) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
-Wno-pedantic
#endif
--
2.39.2
From d7fd9391132a93ae482a003a81bd25afcf1973f8 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Wed, 24 May 2023 10:10:18 -0700
Subject: [PATCH 3/3] manywarnings: speed up nomfi test
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
* m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC): Simplify and speed up
on current platforms, by seeing first whether
-Wno-missing-field-initializers is needed (it isn’t), so that
later we don’t need to determine whether it’s supported.
---
ChangeLog | 6 +++++
m4/manywarnings.m4 | 56 +++++++++++++++++-----------------------------
2 files changed, 27 insertions(+), 35 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index e09a981eec..95302733ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
2023-05-24 Paul Eggert <egg...@cs.ucla.edu>
+ manywarnings: speed up nomfi test
+ * m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC): Simplify and speed up
+ on current platforms, by seeing first whether
+ -Wno-missing-field-initializers is needed (it isn’t), so that
+ later we don’t need to determine whether it’s supported.
+
Simplify -Wno-missing-field-initializers checking
* m4/gnulib-common.m4 (gl_CC_GNULIB_WARNINGS): Don’t worry about
-Wmissing-field-initializers, as this is no longer needed now that
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 77b96295df..7792b4f3b4 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -47,43 +47,29 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
dnl gcc warning categories.
AC_REQUIRE([AC_PROG_CC])
AS_IF([test -n "$GCC"], [
- dnl Check if -Wextra -Werror -Wno-missing-field-initializers is supported
- dnl with the current $CC $CFLAGS $CPPFLAGS.
- AC_CACHE_CHECK([whether -Wno-missing-field-initializers is supported],
- [gl_cv_cc_nomfi_supported],
- [gl_save_CFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS -Wextra -Werror -Wno-missing-field-initializers"
+ AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
+ [gl_cv_cc_nomfi_needed],
+ [gl_cv_cc_nomfi_needed=no
+ gl_save_CFLAGS="$CFLAGS"
+ CFLAGS="$CFLAGS -Wextra -Werror"
AC_COMPILE_IFELSE(
- [AC_LANG_PROGRAM([[]], [[]])],
- [gl_cv_cc_nomfi_supported=yes],
- [gl_cv_cc_nomfi_supported=no])
+ [AC_LANG_PROGRAM(
+ [[struct file_data { int desc, name; };
+ struct cmp { struct file_data file[1]; };
+ void f (struct cmp *r)
+ {
+ typedef struct { int a; int b; } s_t;
+ s_t s1 = { 0, };
+ struct cmp cmp = { .file[0].desc = r->file[0].desc + s1.a };
+ *r = cmp;
+ }
+ ]],
+ [[]])],
+ [],
+ [CFLAGS="$CFLAGS -Wno-missing-field-initializers"
+ AC_COMPILE_IFELSE([],
+ [gl_cv_cc_nomfi_needed=yes])])
CFLAGS="$gl_save_CFLAGS"
- ])
-
- AS_IF([test "$gl_cv_cc_nomfi_supported" = yes], [
- dnl Now check whether -Wno-missing-field-initializers is needed
- dnl for the { 0, } construct.
- AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
- [gl_cv_cc_nomfi_needed],
- [gl_save_CFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS -Wextra -Werror"
- AC_COMPILE_IFELSE(
- [AC_LANG_PROGRAM(
- [[struct file_data { int desc, name; };
- struct cmp { struct file_data file[1]; };
- void f (struct cmp *r)
- {
- typedef struct { int a; int b; } s_t;
- s_t s1 = { 0, };
- struct cmp cmp = { .file[0].desc = r->file[0].desc + s1.a };
- *r = cmp;
- }
- ]],
- [[]])],
- [gl_cv_cc_nomfi_needed=no],
- [gl_cv_cc_nomfi_needed=yes])
- CFLAGS="$gl_save_CFLAGS"
- ])
])
dnl Next, check if -Werror -Wuninitialized is useful with the
--
2.39.2
