[PATCH] include_next: pacify clang -Winclude-next-absolute-path

[Paul Eggert]

Without this change, Ubuntu clang version 16.0.6 (15) issues
warnings like this: “In file included from xalloc-die.c:25:
./error.h:28:3: warning: #include_next in file found relative to
primary source file or found by absolute path; will search from
start of include path [-Winclude-next-absolute-path]”.
And sure enough, each file includes itself rather than the
next include file and it’s only the subsidiary include that
gets around to including the next include file.
* lib/argmatch.c, lib/chdir-long.c, lib/clean-temp-simple.c:
* lib/clean-temp.c, lib/closein.c, lib/closeout.c, lib/copy-acl.c:
* lib/copy-file.c, lib/creat.c, lib/csharpcomp.c:
* lib/csharpexec.c, lib/error.c, lib/exclude.c, lib/execute.c:
* lib/faccessat.c, lib/fopen.c, lib/freopen.c, lib/getopt.c:
* lib/getopt1.c, lib/git-merge-changelog.c, lib/javacomp.c:
* lib/javaexec.c, lib/javaversion.c, lib/mkdir-p.c, lib/open.c:
* lib/openat-die.c, lib/openat.c, lib/os2-spawn.c:
* lib/pagealign_alloc.c, lib/pipe-filter-gi.c:
* lib/pipe-filter-ii.c, lib/same.c, lib/set-acl.c:
* lib/sigpipe-die.c, lib/spawn-pipe.c, lib/sys_socket.c, lib/truncate.c:
* lib/unistd.c, lib/verror.c, lib/wait-process.c, lib/wctype-h.c:
* lib/xalloc-die.c, lib/xfreopen.c, lib/xmemcoll.c, lib/xprintf.c:
* lib/xsetenv.c, lib/xstdopen.c, lib/xstrtol-error.c:
Use ‘#include <foo.h>’ instead of ‘#include "foo.h"’ if foo.h
possibly uses #include_next.  (However, don’t do this on OSF/1
which has its own problems.)
---
 ChangeLog                 | 27 +++++++++++++++++++++++++++
 lib/argmatch.c            |  2 +-
 lib/chdir-long.c          |  2 +-
 lib/clean-temp-simple.c   |  2 +-
 lib/clean-temp.c          |  2 +-
 lib/closein.c             |  2 +-
 lib/closeout.c            |  2 +-
 lib/copy-acl.c            |  2 +-
 lib/copy-file.c           |  2 +-
 lib/creat.c               |  6 +++++-
 lib/csharpcomp.c          |  2 +-
 lib/csharpexec.c          |  2 +-
 lib/error.c               |  2 +-
 lib/exclude.c             |  2 +-
 lib/execute.c             |  2 +-
 lib/faccessat.c           |  6 +++++-
 lib/fopen.c               |  6 +++++-
 lib/freopen.c             |  6 +++++-
 lib/getopt.c              |  2 +-
 lib/getopt1.c             |  2 +-
 lib/git-merge-changelog.c |  2 +-
 lib/javacomp.c            |  2 +-
 lib/javaexec.c            |  2 +-
 lib/javaversion.c         |  2 +-
 lib/mkdir-p.c             |  2 +-
 lib/open.c                |  6 +++++-
 lib/openat-die.c          |  2 +-
 lib/openat.c              |  6 +++++-
 lib/os2-spawn.c           |  2 +-
 lib/pagealign_alloc.c     |  2 +-
 lib/pipe-filter-gi.c      |  2 +-
 lib/pipe-filter-ii.c      |  2 +-
 lib/same.c                |  2 +-
 lib/set-acl.c             |  2 +-
 lib/sigpipe-die.c         |  2 +-
 lib/spawn-pipe.c          |  2 +-
 lib/sys_socket.c          |  2 +-
 lib/truncate.c            |  6 +++++-
 lib/unistd.c              |  2 +-
 lib/verror.c              |  2 +-
 lib/wait-process.c        |  2 +-
 lib/wctype-h.c            |  2 +-
 lib/xalloc-die.c          |  2 +-
 lib/xfreopen.c            |  2 +-
 lib/xmemcoll.c            |  2 +-
 lib/xprintf.c             |  2 +-
 lib/xsetenv.c             |  2 +-
 lib/xstdopen.c            |  2 +-
 lib/xstrtol-error.c       |  2 +-
 49 files changed, 103 insertions(+), 48 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 746a1ea70f..d07835db5b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,32 @@
 2023-12-28  Paul Eggert  <eggert@cs.ucla.edu>
 
+       include_next: pacify clang -Winclude-next-absolute-path
+       Without this change, Ubuntu clang version 16.0.6 (15) issues
+       warnings like this: “In file included from xalloc-die.c:25:
+       ./error.h:28:3: warning: #include_next in file found relative to
+       primary source file or found by absolute path; will search from
+       start of include path [-Winclude-next-absolute-path]”.
+       And sure enough, each file includes itself rather than the
+       next include file and it’s only the subsidiary include that
+       gets around to including the next include file.
+       * lib/argmatch.c, lib/chdir-long.c, lib/clean-temp-simple.c:
+       * lib/clean-temp.c, lib/closein.c, lib/closeout.c, lib/copy-acl.c:
+       * lib/copy-file.c, lib/creat.c, lib/csharpcomp.c:
+       * lib/csharpexec.c, lib/error.c, lib/exclude.c, lib/execute.c:
+       * lib/faccessat.c, lib/fopen.c, lib/freopen.c, lib/getopt.c:
+       * lib/getopt1.c, lib/git-merge-changelog.c, lib/javacomp.c:
+       * lib/javaexec.c, lib/javaversion.c, lib/mkdir-p.c, lib/open.c:
+       * lib/openat-die.c, lib/openat.c, lib/os2-spawn.c:
+       * lib/pagealign_alloc.c, lib/pipe-filter-gi.c:
+       * lib/pipe-filter-ii.c, lib/same.c, lib/set-acl.c:
+       * lib/sigpipe-die.c, lib/spawn-pipe.c, lib/sys_socket.c, lib/truncate.c:
+       * lib/unistd.c, lib/verror.c, lib/wait-process.c, lib/wctype-h.c:
+       * lib/xalloc-die.c, lib/xfreopen.c, lib/xmemcoll.c, lib/xprintf.c:
+       * lib/xsetenv.c, lib/xstdopen.c, lib/xstrtol-error.c:
+       Use ‘#include <foo.h>’ instead of ‘#include "foo.h"’ if foo.h
+       possibly uses #include_next.  (However, don’t do this on OSF/1
+       which has its own problems.)
+
        stat-time: fix macOS bug with negative file times
        macOS has a bug similar (but not identical) to Solaris when
        file timestamps are negative: tv_nsec might go negative.
diff --git a/lib/argmatch.c b/lib/argmatch.c
index 9cddb37d69..ad2b269055 100644
--- a/lib/argmatch.c
+++ b/lib/argmatch.c
@@ -30,7 +30,7 @@
 
 #define _(msgid) gettext (msgid)
 
-#include "error.h"
+#include <error.h>
 #include "quotearg.h"
 
 #if USE_UNLOCKED_IO
diff --git a/lib/chdir-long.c b/lib/chdir-long.c
index 8a25538b3f..de5aaee74f 100644
--- a/lib/chdir-long.c
+++ b/lib/chdir-long.c
@@ -209,7 +209,7 @@ chdir_long (char *dir)
 #if TEST_CHDIR
 
 # include "closeout.h"
-# include "error.h"
+# include <error.h>
 
 int
 main (int argc, char *argv[])
diff --git a/lib/clean-temp-simple.c b/lib/clean-temp-simple.c
index 66eeb1ea69..9e9beb829d 100644
--- a/lib/clean-temp-simple.c
+++ b/lib/clean-temp-simple.c
@@ -28,7 +28,7 @@
 #include <string.h>
 #include <unistd.h>
 
-#include "error.h"
+#include <error.h>
 #include "fatal-signal.h"
 #include "asyncsafe-spin.h"
 #include "glthread/lock.h"
diff --git a/lib/clean-temp.c b/lib/clean-temp.c
index de16292b36..ec7fb4b319 100644
--- a/lib/clean-temp.c
+++ b/lib/clean-temp.c
@@ -36,7 +36,7 @@
 
 #include "clean-temp-simple.h"
 #include "clean-temp-private.h"
-#include "error.h"
+#include <error.h>
 #include "fatal-signal.h"
 #include "asyncsafe-spin.h"
 #include "pathmax.h"
diff --git a/lib/closein.c b/lib/closein.c
index d26de8d078..930169a1d6 100644
--- a/lib/closein.c
+++ b/lib/closein.c
@@ -28,7 +28,7 @@
 
 #include "close-stream.h"
 #include "closeout.h"
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "freadahead.h"
 #include "quotearg.h"
diff --git a/lib/closeout.c b/lib/closeout.c
index d9e8211303..813869a3ac 100644
--- a/lib/closeout.c
+++ b/lib/closeout.c
@@ -28,7 +28,7 @@
 #define _(msgid) gettext (msgid)
 
 #include "close-stream.h"
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "quotearg.h"
 
diff --git a/lib/copy-acl.c b/lib/copy-acl.c
index 3606a5017d..d7beececb6 100644
--- a/lib/copy-acl.c
+++ b/lib/copy-acl.c
@@ -24,7 +24,7 @@
 #include <errno.h>
 
 #include "quote.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 #define _(msgid) gettext (msgid)
 
diff --git a/lib/copy-file.c b/lib/copy-file.c
index 78da3996bb..4132f69dff 100644
--- a/lib/copy-file.c
+++ b/lib/copy-file.c
@@ -28,7 +28,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "error.h"
+#include <error.h>
 #include "ignore-value.h"
 #include "safe-read.h"
 #include "full-write.h"
diff --git a/lib/creat.c b/lib/creat.c
index dad7b2da45..49b7a453a4 100644
--- a/lib/creat.c
+++ b/lib/creat.c
@@ -36,9 +36,13 @@ orig_creat (const char *filename, mode_t mode)
 }
 
 /* Specification.  */
+#ifdef __osf__
 /* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
    this include because of the preliminary #include <fcntl.h> above.  */
-#include "fcntl.h"
+# include "fcntl.h"
+#else
+# include <fcntl.h>
+#endif
 
 #include <errno.h>
 #include <string.h>
diff --git a/lib/csharpcomp.c b/lib/csharpcomp.c
index 03b7da1f7b..89f7a7c10d 100644
--- a/lib/csharpcomp.c
+++ b/lib/csharpcomp.c
@@ -32,7 +32,7 @@
 #include "sh-quote.h"
 #include "safe-read.h"
 #include "xmalloca.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 #define _(str) gettext (str)
diff --git a/lib/csharpexec.c b/lib/csharpexec.c
index 2e30198c29..bf85ab849e 100644
--- a/lib/csharpexec.c
+++ b/lib/csharpexec.c
@@ -27,7 +27,7 @@
 #include "execute.h"
 #include "sh-quote.h"
 #include "xmalloca.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 /* Handling of MONO_PATH is just like Java CLASSPATH.  */
diff --git a/lib/error.c b/lib/error.c
index 9e26391e98..72f248f157 100644
--- a/lib/error.c
+++ b/lib/error.c
@@ -22,7 +22,7 @@
 # define _GL_NO_INLINE_ERROR
 #endif
 
-#include "error.h"
+#include <error.h>
 
 #include <stdarg.h>
 #include <stdio.h>
diff --git a/lib/exclude.c b/lib/exclude.c
index a3479db8a6..43456a3fd5 100644
--- a/lib/exclude.c
+++ b/lib/exclude.c
@@ -34,7 +34,7 @@
 
 #include "exclude.h"
 #include "filename.h"
-#include "fnmatch.h"
+#include <fnmatch.h>
 #include "hash.h"
 #if GNULIB_MCEL_PREFER
 # include "mcel.h"
diff --git a/lib/execute.c b/lib/execute.c
index b2164f1688..33d98a4175 100644
--- a/lib/execute.c
+++ b/lib/execute.c
@@ -31,7 +31,7 @@
 #include <sys/wait.h>
 
 #include "canonicalize.h"
-#include "error.h"
+#include <error.h>
 #include "fatal-signal.h"
 #include "filename.h"
 #include "findprog.h"
diff --git a/lib/faccessat.c b/lib/faccessat.c
index ac8977cfd6..ee83806844 100644
--- a/lib/faccessat.c
+++ b/lib/faccessat.c
@@ -40,10 +40,14 @@ orig_faccessat (int fd, char const *name, int mode, int 
flag)
 }
 #endif
 
+#ifdef __osf__
 /* Write "unistd.h" here, not <unistd.h>, otherwise OSF/1 5.1 DTK cc
    eliminates this include because of the preliminary #include <unistd.h>
    above.  */
-#include "unistd.h"
+# include "unistd.h"
+#else
+# include <unistd.h>
+#endif
 
 #ifndef HAVE_ACCESS
 /* Mingw lacks access, but it also lacks real vs. effective ids, so
diff --git a/lib/fopen.c b/lib/fopen.c
index e1e4cdbd23..9cb6176fb0 100644
--- a/lib/fopen.c
+++ b/lib/fopen.c
@@ -33,9 +33,13 @@ orig_fopen (const char *filename, const char *mode)
 }
 
 /* Specification.  */
+#ifdef __osf__
 /* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
    this include because of the preliminary #include <stdio.h> above.  */
-#include "stdio.h"
+# include "stdio.h"
+#else
+# include <stdio.h>
+#endif
 
 #include <errno.h>
 #include <fcntl.h>
diff --git a/lib/freopen.c b/lib/freopen.c
index 646aa7c817..52332b74d6 100644
--- a/lib/freopen.c
+++ b/lib/freopen.c
@@ -35,9 +35,13 @@ orig_freopen (const char *filename, const char *mode, FILE 
*stream)
 }
 
 /* Specification.  */
+#ifdef __osf__
 /* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
    this include because of the preliminary #include <stdio.h> above.  */
-#include "stdio.h"
+# include "stdio.h"
+#else
+# include <stdio.h>
+#endif
 
 #include <fcntl.h>
 #include <string.h>
diff --git a/lib/getopt.c b/lib/getopt.c
index a2a291d697..43dd5dad61 100644
--- a/lib/getopt.c
+++ b/lib/getopt.c
@@ -21,7 +21,7 @@
 # include <config.h>
 #endif
 
-#include "getopt.h"
+#include <getopt.h>
 
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/lib/getopt1.c b/lib/getopt1.c
index 49323aa8ed..587daa2a6f 100644
--- a/lib/getopt1.c
+++ b/lib/getopt1.c
@@ -21,7 +21,7 @@
 # include <config.h>
 #endif
 
-#include "getopt.h"
+#include <getopt.h>
 #include "getopt_int.h"
 
 int
diff --git a/lib/git-merge-changelog.c b/lib/git-merge-changelog.c
index 2ef745ec9d..c701d29942 100644
--- a/lib/git-merge-changelog.c
+++ b/lib/git-merge-changelog.c
@@ -164,7 +164,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include "error.h"
+#include <error.h>
 #include "idx.h"
 #include "read-file.h"
 #include "gl_xlist.h"
diff --git a/lib/javacomp.c b/lib/javacomp.c
index b4bf298d29..e55b18e2e8 100644
--- a/lib/javacomp.c
+++ b/lib/javacomp.c
@@ -44,7 +44,7 @@
 #include "concat-filename.h"
 #include "fwriteerror.h"
 #include "clean-temp.h"
-#include "error.h"
+#include <error.h>
 #include "xvasprintf.h"
 #include "verify.h"
 #include "c-strstr.h"
diff --git a/lib/javaexec.c b/lib/javaexec.c
index 6f4af37485..20d0068fe9 100644
--- a/lib/javaexec.c
+++ b/lib/javaexec.c
@@ -32,7 +32,7 @@
 #include "concat-filename.h"
 #include "xalloc.h"
 #include "xmalloca.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 #define _(str) gettext (str)
diff --git a/lib/javaversion.c b/lib/javaversion.c
index aef1be3077..9c1225e7c7 100644
--- a/lib/javaversion.c
+++ b/lib/javaversion.c
@@ -34,7 +34,7 @@
 #include "javaexec.h"
 #include "spawn-pipe.h"
 #include "wait-process.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 #define _(str) gettext (str)
diff --git a/lib/mkdir-p.c b/lib/mkdir-p.c
index 67e9050ad6..2cb0bc9bc1 100644
--- a/lib/mkdir-p.c
+++ b/lib/mkdir-p.c
@@ -31,7 +31,7 @@
 
 #include "dirchownmod.h"
 #include "dirname.h"
-#include "error.h"
+#include <error.h>
 #include "quote.h"
 #include "mkancesdirs.h"
 #include "savewd.h"
diff --git a/lib/open.c b/lib/open.c
index 7ec8fdc35d..d9af5a2a35 100644
--- a/lib/open.c
+++ b/lib/open.c
@@ -38,9 +38,13 @@ orig_open (const char *filename, int flags, mode_t mode)
 }
 
 /* Specification.  */
+#ifdef __osf__
 /* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
    this include because of the preliminary #include <fcntl.h> above.  */
-#include "fcntl.h"
+# include "fcntl.h"
+#else
+# include <fcntl.h>
+#endif
 
 #include "cloexec.h"
 
diff --git a/lib/openat-die.c b/lib/openat-die.c
index df3dbc9b66..84bc543706 100644
--- a/lib/openat-die.c
+++ b/lib/openat-die.c
@@ -22,7 +22,7 @@
 #include <stdlib.h>
 
 #ifndef GNULIB_LIBPOSIX
-# include "error.h"
+# include <error.h>
 #endif
 
 #include "exitfail.h"
diff --git a/lib/openat.c b/lib/openat.c
index f28b10e138..160a02e5d5 100644
--- a/lib/openat.c
+++ b/lib/openat.c
@@ -35,9 +35,13 @@ orig_openat (int fd, char const *filename, int flags, mode_t 
mode)
 }
 #endif
 
+#ifdef __osf__
 /* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
    this include because of the preliminary #include <fcntl.h> above.  */
-#include "fcntl.h"
+# include "fcntl.h"
+#else
+# include <fcntl.h>
+#endif
 
 #include "openat.h"
 
diff --git a/lib/os2-spawn.c b/lib/os2-spawn.c
index c47f33afc3..305226288c 100644
--- a/lib/os2-spawn.c
+++ b/lib/os2-spawn.c
@@ -29,7 +29,7 @@
 #include <errno.h>
 
 #include "cloexec.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 #define _(str) gettext (str)
diff --git a/lib/pagealign_alloc.c b/lib/pagealign_alloc.c
index fa74c09fd4..73ebd9d74a 100644
--- a/lib/pagealign_alloc.c
+++ b/lib/pagealign_alloc.c
@@ -31,7 +31,7 @@
 # include <sys/mman.h>
 #endif
 
-#include "error.h"
+#include <error.h>
 #include "xalloc.h"
 #include "gettext.h"
 
diff --git a/lib/pipe-filter-gi.c b/lib/pipe-filter-gi.c
index 5b04bf7c7d..94b562286a 100644
--- a/lib/pipe-filter-gi.c
+++ b/lib/pipe-filter-gi.c
@@ -33,7 +33,7 @@
 # include <sys/select.h>
 #endif
 
-#include "error.h"
+#include <error.h>
 #include "spawn-pipe.h"
 #include "wait-process.h"
 #include "xalloc.h"
diff --git a/lib/pipe-filter-ii.c b/lib/pipe-filter-ii.c
index 1730e8175b..abc76c284c 100644
--- a/lib/pipe-filter-ii.c
+++ b/lib/pipe-filter-ii.c
@@ -153,7 +153,7 @@ WaitForMultipleObjects (DWORD nCount, const HANDLE 
*pHandles, BOOL bWaitAll,
 # include <sys/select.h>
 #endif
 
-#include "error.h"
+#include <error.h>
 #include "spawn-pipe.h"
 #include "wait-process.h"
 #include "gettext.h"
diff --git a/lib/same.c b/lib/same.c
index 82a5cc3cff..c6426087f9 100644
--- a/lib/same.c
+++ b/lib/same.c
@@ -37,7 +37,7 @@
 
 #include "same.h"
 #include "dirname.h"
-#include "error.h"
+#include <error.h>
 #include "same-inode.h"
 
 #ifndef MIN
diff --git a/lib/set-acl.c b/lib/set-acl.c
index fac5665df2..19bc4aaf31 100644
--- a/lib/set-acl.c
+++ b/lib/set-acl.c
@@ -24,7 +24,7 @@
 #include <errno.h>
 
 #include "quote.h"
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 #define _(msgid) gettext (msgid)
 
diff --git a/lib/sigpipe-die.c b/lib/sigpipe-die.c
index 3202eac4cd..b2d7ab71f3 100644
--- a/lib/sigpipe-die.c
+++ b/lib/sigpipe-die.c
@@ -24,7 +24,7 @@
 #include <signal.h>
 #include <stdlib.h>
 
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 
 #include "gettext.h"
diff --git a/lib/spawn-pipe.c b/lib/spawn-pipe.c
index d2d21e6e8e..42d713817e 100644
--- a/lib/spawn-pipe.c
+++ b/lib/spawn-pipe.c
@@ -33,7 +33,7 @@
 #include <unistd.h>
 
 #include "canonicalize.h"
-#include "error.h"
+#include <error.h>
 #include "fatal-signal.h"
 #include "filename.h"
 #include "findprog.h"
diff --git a/lib/sys_socket.c b/lib/sys_socket.c
index b7388ceccf..a4e845957f 100644
--- a/lib/sys_socket.c
+++ b/lib/sys_socket.c
@@ -18,5 +18,5 @@
 #include <config.h>
 
 #define _GL_SYS_SOCKET_INLINE _GL_EXTERN_INLINE
-#include "sys/socket.h"
+#include <sys/socket.h>
 typedef int dummy;
diff --git a/lib/truncate.c b/lib/truncate.c
index 0541e346d3..a04bff3fd5 100644
--- a/lib/truncate.c
+++ b/lib/truncate.c
@@ -37,10 +37,14 @@ orig_truncate (const char *filename, off_t length)
 }
 #endif
 
+#ifdef __osf__
 /* Write "unistd.h" here, not <unistd.h>, otherwise OSF/1 5.1 DTK cc
    eliminates this include because of the preliminary #include <unistd.h>
    above.  */
-#include "unistd.h"
+# include "unistd.h"
+#else
+# include <unistd.h>
+#endif
 
 int
 truncate (const char *filename, off_t length)
diff --git a/lib/unistd.c b/lib/unistd.c
index be7a825503..98bdb4e265 100644
--- a/lib/unistd.c
+++ b/lib/unistd.c
@@ -18,5 +18,5 @@
 #include <config.h>
 
 #define _GL_UNISTD_INLINE _GL_EXTERN_INLINE
-#include "unistd.h"
+#include <unistd.h>
 typedef int dummy;
diff --git a/lib/verror.c b/lib/verror.c
index 46bb230443..acaa6e0a40 100644
--- a/lib/verror.c
+++ b/lib/verror.c
@@ -25,7 +25,7 @@
 #include <stdarg.h>
 #include <stdlib.h>
 
-#include "error.h"
+#include <error.h>
 #include "xvasprintf.h"
 
 #if ENABLE_NLS
diff --git a/lib/wait-process.c b/lib/wait-process.c
index 3e95b4efb5..012c52ae6c 100644
--- a/lib/wait-process.c
+++ b/lib/wait-process.c
@@ -29,7 +29,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 
-#include "error.h"
+#include <error.h>
 #include "fatal-signal.h"
 #include "xalloc.h"
 #include "gettext.h"
diff --git a/lib/wctype-h.c b/lib/wctype-h.c
index 7d3e14a6b5..c8f1eb4905 100644
--- a/lib/wctype-h.c
+++ b/lib/wctype-h.c
@@ -20,4 +20,4 @@
 #include <config.h>
 
 #define _GL_WCTYPE_INLINE _GL_EXTERN_INLINE
-#include "wctype.h"
+#include <wctype.h>
diff --git a/lib/xalloc-die.c b/lib/xalloc-die.c
index 7605eee151..d4461c793d 100644
--- a/lib/xalloc-die.c
+++ b/lib/xalloc-die.c
@@ -22,7 +22,7 @@
 
 #include <stdlib.h>
 
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 
 #include "gettext.h"
diff --git a/lib/xfreopen.c b/lib/xfreopen.c
index e776ff70c1..5620d214b6 100644
--- a/lib/xfreopen.c
+++ b/lib/xfreopen.c
@@ -18,7 +18,7 @@
 #include "xfreopen.h"
 
 #include <errno.h>
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "quote.h"
 
diff --git a/lib/xmemcoll.c b/lib/xmemcoll.c
index 5a15d2b221..02bf66b60f 100644
--- a/lib/xmemcoll.c
+++ b/lib/xmemcoll.c
@@ -25,7 +25,7 @@
 #include "gettext.h"
 #define _(msgid) gettext (msgid)
 
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "memcoll.h"
 #include "quotearg.h"
diff --git a/lib/xprintf.c b/lib/xprintf.c
index fbdd96cce4..ef4a619960 100644
--- a/lib/xprintf.c
+++ b/lib/xprintf.c
@@ -20,7 +20,7 @@
 
 #include <errno.h>
 
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "gettext.h"
 
diff --git a/lib/xsetenv.c b/lib/xsetenv.c
index 2763997df6..b01f2945e8 100644
--- a/lib/xsetenv.c
+++ b/lib/xsetenv.c
@@ -21,7 +21,7 @@
 
 #include <stdlib.h>
 
-#include "error.h"
+#include <error.h>
 #include "gettext.h"
 
 #define _(str) gettext (str)
diff --git a/lib/xstdopen.c b/lib/xstdopen.c
index 76d4781528..0cf4053ac1 100644
--- a/lib/xstdopen.c
+++ b/lib/xstdopen.c
@@ -20,7 +20,7 @@
 #include "xstdopen.h"
 
 #include "stdopen.h"
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 
 #include "gettext.h"
diff --git a/lib/xstrtol-error.c b/lib/xstrtol-error.c
index 7749e02137..5100542236 100644
--- a/lib/xstrtol-error.c
+++ b/lib/xstrtol-error.c
@@ -21,7 +21,7 @@
 
 #include <stdlib.h>
 
-#include "error.h"
+#include <error.h>
 #include "exitfail.h"
 #include "gettext.h"
 
-- 
2.40.1