This is the mail archive of the
glibc-cvs@sourceware.org
mailing list for the glibc project.
[glibc/zack/no-nested-includes] Linux: Fix __glibc_has_include use for <sys/stat.h> and statx
- From: Zack Weinberg <zack at sourceware dot org>
- To: glibc-cvs at sourceware dot org
- Date: 18 Jun 2019 15:32:09 -0000
- Subject: [glibc/zack/no-nested-includes] Linux: Fix __glibc_has_include use for <sys/stat.h> and statx
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=48c3c1238925410b4e777dc94e2fde4cc9132d44
commit 48c3c1238925410b4e777dc94e2fde4cc9132d44
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Jun 14 16:28:41 2019 +0200
Linux: Fix __glibc_has_include use for <sys/stat.h> and statx
The identifier linux is used as a predefined macro, so the actually
used path is 1/stat.h or 1/stat64.h. Using the quote-based version
triggers a file lookup for /usr/include/bits/linux/stat.h (or whatever
directory is used to store bits/statx.h), but since bits/ is pretty
much reserved by glibc, this appears to be acceptable.
This is related to GCC PR 80005: incorrect macro expansion of the
argument of __has_include.
Suggested by Zack Weinberg.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diff:
---
ChangeLog | 5 +++++
sysdeps/unix/sysv/linux/bits/statx.h | 7 +++++--
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 4aae5e7..efd86e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
2019-06-14 Florian Weimer <fweimer@redhat.com>
+ * sysdeps/unix/sysv/linux/bits/statx.h: Use string literal in
+ argument to __glibc_has_include to inhibit macro expansion.
+
+2019-06-14 Florian Weimer <fweimer@redhat.com>
+
* misc/sys/cdefs.h (__glibc_has_include): Do not use a
function-like macro, so that __has_include can inhibit expansion
of its argument.
diff --git a/sysdeps/unix/sysv/linux/bits/statx.h b/sysdeps/unix/sysv/linux/bits/statx.h
index d36f44e..2068787 100644
--- a/sysdeps/unix/sysv/linux/bits/statx.h
+++ b/sysdeps/unix/sysv/linux/bits/statx.h
@@ -23,8 +23,11 @@
#endif
/* Use the Linux kernel header if available. */
-#if __glibc_has_include (<linux/stat.h>)
-# include <linux/stat.h>
+
+/* Use "" to work around incorrect macro expansion of the
+ __has_include argument (GCC PR 80005). */
+#if __glibc_has_include ("linux/stat.h")
+# include "linux/stat.h"
# ifdef STATX_TYPE
# define __statx_timestamp_defined 1
# define __statx_defined 1