* glob-h: Avoid conflict with preprocessor macros owned by the system
@ 2021-06-06 22:50 Bruno Haible
2021-06-06 23:22 ` dynarray, scratch_buffer: " Bruno Haible
0 siblings, 1 reply; 3+ messages in thread
From: Bruno Haible @ 2021-06-06 22:50 UTC (permalink / raw)
To: bug-gnulib
Building a testdir created with
./gnulib-tool --create-testdir --dir=../testdir --with-c++-tests \
--without-privileged-tests --single-configure \
dynarray glob scratch_buffer
on DragonFly BSD 6.0, I see this error:
In file included from ../../gltests/../gllib/libc-config.h:158,
from ../gllib/glob.h:581,
from ../../gltests/test-glob-h-c++.cc:22:
/usr/include/machine/endian.h:152:17: error: duplicate 'inline'
static __inline __always_inline __uint64_t
^~~~~~~~~~~~~~~
/usr/include/machine/endian.h:162:17: error: duplicate 'inline'
static __inline __always_inline __uint32_t
^~~~~~~~~~~~~~~
/usr/include/machine/endian.h:172:17: error: duplicate 'inline'
static __inline __always_inline __uint16_t
^~~~~~~~~~~~~~~
What happens here is a conflict between the definition of
'__always_inline' in gnulib's <cdefs.h> (included from
glob.h -> libc-config.h -> cdefs.h) and the definition of
'__always_inline' in DragonFly's <sys/cdefs.h>.
In C++ it is invalid to write
static __inline __inline ... some_function (...) { ... }
The DragonFly headers are consistent: They define
#define __always_inline __attribute__((__always_inline__))
and use it like this in <machine/endian.h>:
static __inline __always_inline __uint64_t __bswap64 ...
Gnulib's <cdefs.h> definition of __always_inline is tailored for
glibc sources, which do
static __always_inline bool ...
Therefore it defines it as
#define __always_inline __inline __attribute__ ((__always_inline__))
But gnulib's <cdefs.h> *overrides* the system's definition. And it
is visible after any of these header files has been included:
lib/dynarray.h
lib/glob.in.h
lib/scratch_buffer.h
After one of these files has been included, the application can
include any system include file, and these system include files will
typically rely on the system's definition of __* macros from <sys/cdefs.h>.
It's a different thing to include <cdefs.h> for the compilation of
a Gnulib .c file than to expose it through a .h file that the application
can include. In the first case, the Gnulib .c file includes a small set
of system's .h files, and therefore we can hope to have resolved the
possible conflicts in a reasonable amount of time. In the second case,
there is an uncountable number of conflicts; so, this problem will
haunt us for years if we don't fix it.
My fix here is to process the glob-libc.h file so that it does not
rely on __* macros (that belong to the system's namespace), only on
Gnulib macros, which we haven't seen conflict with system headers in
17 years.
When glob-libc.h changes (following merges from glibc), the processing
steps in modules/glob-h might need changes, but they will typically
be small and straightforward.
2021-06-06 Bruno Haible <bruno@clisp.org>
glob-h: Avoid conflict with preprocessor macros owned by the system.
This fixes a compilation error on DragonFly BSD 6.0.
* lib/glob.in.h: Don't include <libc-config.h>. Don't define __USE_GNU.
Include glob-libc.gl.h instead of glob-libc.h.
* modules/glob-h (Makefile.am): Arrange to create glob-libc.gl.h from
glob-libc.h.
* lib/libc-config.h: Add comment.
diff --git a/lib/glob.in.h b/lib/glob.in.h
index 4952666..dbc5b63 100644
--- a/lib/glob.in.h
+++ b/lib/glob.in.h
@@ -70,10 +70,6 @@ typedef int (*_gl_glob_errfunc_fn) (const char *, int);
/* Preparations for including the standard GNU C Library header. */
-# ifndef __attribute_maybe_unused__
-# include <libc-config.h>
-# endif
-
# include <stddef.h>
/* On some systems, such as AIX 5.1, <sys/stat.h> does a "#define stat stat64".
@@ -81,10 +77,6 @@ typedef int (*_gl_glob_errfunc_fn) (const char *, int);
rely on 'struct stat'. */
# include <sys/stat.h>
-# ifndef __USE_GNU
-# define __USE_GNU 1
-# endif
-
# if @REPLACE_GLOB@
# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
# define glob rpl_glob
@@ -102,7 +94,7 @@ typedef int (*_gl_glob_errfunc_fn) (const char *, int);
/* Now the standard GNU C Library header should work. */
-# include "glob-libc.h"
+# include "glob-libc.gl.h"
#endif
diff --git a/lib/libc-config.h b/lib/libc-config.h
index fabca2f..f68749f 100644
--- a/lib/libc-config.h
+++ b/lib/libc-config.h
@@ -28,7 +28,10 @@
When compiled as part of glibc this is a no-op; when compiled as
part of Gnulib this includes Gnulib's <config.h> and defines macros
- that glibc library code would normally assume. */
+ that glibc library code would normally assume.
+
+ Note: This header file MUST NOT be included by public header files
+ of Gnulib. */
#include <config.h>
diff --git a/modules/glob-h b/modules/glob-h
index 40df48f..0b71fd2 100644
--- a/modules/glob-h
+++ b/modules/glob-h
@@ -51,6 +51,23 @@ glob.h: $(top_builddir)/config.status
endif
MOSTLYCLEANFILES += glob.h glob.h-t
+BUILT_SOURCES += glob-libc.gl.h
+
+glob-libc.gl.h: glob-libc.h
+ $(AM_V_GEN)rm -f $@-t $@ && \
+ { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+ sed -e '/__BEGIN_DECLS/{ s/__BEGIN_DECLS/#ifdef __cplusplus%extern "C" {%#endif/; y/%/\n/; }' \
+ -e '/__END_DECLS/{ s/__END_DECLS/#ifdef __cplusplus%}%#endif/; y/%/\n/; }' \
+ -e 's|__THROW||g' \
+ -e 's|defined __USE_MISC|1|' \
+ -e 's|ifdef __USE_GNU|if 1|' \
+ -e 's|ifdef __USE_LARGEFILE64|if 0|' \
+ < $(srcdir)/glob-libc.h; \
+ } > $@-t && \
+ mv $@-t $@
+MOSTLYCLEANFILES += glob-libc.gl.h glob-libc.gl.h-t
+
+
Include:
<glob.h>
^ permalink raw reply related [flat|nested] 3+ messages in thread
* dynarray, scratch_buffer: Avoid conflict with preprocessor macros owned by the system
2021-06-06 22:50 glob-h: Avoid conflict with preprocessor macros owned by the system Bruno Haible
@ 2021-06-06 23:22 ` Bruno Haible
2021-06-08 0:41 ` Bruno Haible
0 siblings, 1 reply; 3+ messages in thread
From: Bruno Haible @ 2021-06-06 23:22 UTC (permalink / raw)
To: bug-gnulib
[-- Attachment #1: Type: text/plain, Size: 2051 bytes --]
> But gnulib's <cdefs.h> *overrides* the system's definition. And it
> is visible after any of these header files has been included:
>
> lib/dynarray.h
> lib/glob.in.h
> lib/scratch_buffer.h
>
> After one of these files has been included, the application can
> include any system include file, and these system include files will
> typically rely on the system's definition of __* macros from <sys/cdefs.h>.
>
> It's a different thing to include <cdefs.h> for the compilation of
> a Gnulib .c file than to expose it through a .h file that the application
> can include. In the first case, the Gnulib .c file includes a small set
> of system's .h files, and therefore we can hope to have resolved the
> possible conflicts in a reasonable amount of time. In the second case,
> there is an uncountable number of conflicts; so, this problem will
> haunt us for years if we don't fix it.
>
> My fix here is to process the glob-libc.h file so that it does not
> rely on __* macros (that belong to the system's namespace)
And likewise for dynarray.h and scratch_buffer.h.
2021-06-06 Bruno Haible <bruno@clisp.org>
scratch_buffer: Avoid conflict with prepr. macros owned by the system.
* lib/scratch_buffer.h: Don't include <libc-config.h>. Define
_GL_LIKELY, _GL_UNLIKELY. Include malloc/scratch_buffer.gl.h instead of
malloc/scratch_buffer.h.
* modules/scratch_buffer (Depends-on): Add builtin-expect.
(Makefile.am): Arrange to create malloc/scratch_buffer.gl.h from
malloc/scratch_buffer.h.
2021-06-06 Bruno Haible <bruno@clisp.org>
dynarray: Avoid conflict with preprocessor macros owned by the system.
* lib/dynarray.h: Don't include <libc-config.h>. Define _GL_LIKELY,
_GL_UNLIKELY. Include malloc/dynarray.gl.h instead of malloc/dynarray.h.
Include malloc/dynarray-skeleton.gl.h instead of
malloc/dynarray-skeleton.c.
* modules/dynarray (Depends-on): Add builtin-expect.
(Makefile.am): Arrange to create malloc/dynarray.gl.h from
malloc/dynarray.h and malloc/dynarray-skeleton.gl.h from
malloc/dynarray-skeleton.c.
[-- Attachment #2: 0001-dynarray-Avoid-conflict-with-preprocessor-macros-own.patch --]
[-- Type: text/x-patch, Size: 4155 bytes --]
From 0c907f7da13232908f05c415b8cec56024071906 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Mon, 7 Jun 2021 00:54:25 +0200
Subject: [PATCH 1/3] dynarray: Avoid conflict with preprocessor macros owned
by the system.
* lib/dynarray.h: Don't include <libc-config.h>. Define _GL_LIKELY,
_GL_UNLIKELY. Include malloc/dynarray.gl.h instead of malloc/dynarray.h.
Include malloc/dynarray-skeleton.gl.h instead of
malloc/dynarray-skeleton.c.
* modules/dynarray (Depends-on): Add builtin-expect.
(Makefile.am): Arrange to create malloc/dynarray.gl.h from
malloc/dynarray.h and malloc/dynarray-skeleton.gl.h from
malloc/dynarray-skeleton.c.
---
ChangeLog | 12 ++++++++++++
lib/dynarray.h | 10 +++++++---
modules/dynarray | 25 +++++++++++++++++++++++++
3 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 79fc6ff..b354ff0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
2021-06-06 Bruno Haible <bruno@clisp.org>
+ dynarray: Avoid conflict with preprocessor macros owned by the system.
+ * lib/dynarray.h: Don't include <libc-config.h>. Define _GL_LIKELY,
+ _GL_UNLIKELY. Include malloc/dynarray.gl.h instead of malloc/dynarray.h.
+ Include malloc/dynarray-skeleton.gl.h instead of
+ malloc/dynarray-skeleton.c.
+ * modules/dynarray (Depends-on): Add builtin-expect.
+ (Makefile.am): Arrange to create malloc/dynarray.gl.h from
+ malloc/dynarray.h and malloc/dynarray-skeleton.gl.h from
+ malloc/dynarray-skeleton.c.
+
+2021-06-06 Bruno Haible <bruno@clisp.org>
+
glob-h: Avoid conflict with preprocessor macros owned by the system.
This fixes a compilation error on DragonFly BSD 6.0.
* lib/glob.in.h: Don't include <libc-config.h>. Don't define __USE_GNU.
diff --git a/lib/dynarray.h b/lib/dynarray.h
index 375d3da..ec64273 100644
--- a/lib/dynarray.h
+++ b/lib/dynarray.h
@@ -257,18 +257,22 @@ static DYNARRAY_ELEMENT *
#if defined DYNARRAY_STRUCT || defined DYNARRAY_ELEMENT || defined DYNARRAY_PREFIX
-# include <libc-config.h>
+# ifndef _GL_LIKELY
+/* Rely on __builtin_expect, as provided by the module 'builtin-expect'. */
+# define _GL_LIKELY(cond) __builtin_expect ((cond), 1)
+# define _GL_UNLIKELY(cond) __builtin_expect ((cond), 0)
+# endif
/* Define auxiliary structs and declare auxiliary functions, common to all
instantiations of dynarray. */
-# include <malloc/dynarray.h>
+# include <malloc/dynarray.gl.h>
/* Define the instantiation, specified through
DYNARRAY_STRUCT
DYNARRAY_ELEMENT
DYNARRAY_PREFIX
etc. */
-# include <malloc/dynarray-skeleton.c>
+# include <malloc/dynarray-skeleton.gl.h>
#else
diff --git a/modules/dynarray b/modules/dynarray
index dcdcba4..7fd444f 100644
--- a/modules/dynarray
+++ b/modules/dynarray
@@ -13,6 +13,7 @@ lib/malloc/dynarray_resize_clear.c
Depends-on:
c99
+builtin-expect
libc-config
stdbool
stddef
@@ -21,6 +22,30 @@ intprops
configure.ac:
Makefile.am:
+BUILT_SOURCES += malloc/dynarray.gl.h malloc/dynarray-skeleton.gl.h
+
+malloc/dynarray.gl.h: malloc/dynarray.h
+ $(AM_V_GEN)rm -f $@-t $@ && \
+ { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+ sed -e '/libc_hidden_proto/d' < $(srcdir)/malloc/dynarray.h; \
+ } > $@-t && \
+ mv $@-t $@
+MOSTLYCLEANFILES += malloc/dynarray.gl.h malloc/dynarray.gl.h-t
+
+malloc/dynarray-skeleton.gl.h: malloc/dynarray-skeleton.c
+ $(AM_V_GEN)rm -f $@-t $@ && \
+ { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+ sed -e 's|<malloc/dynarray\.h>|<malloc/dynarray.gl.h>|g' \
+ -e 's|__attribute_maybe_unused__|_GL_ATTRIBUTE_MAYBE_UNUSED|g' \
+ -e 's|__attribute_nonnull__|_GL_ATTRIBUTE_NONNULL|g' \
+ -e 's|__attribute_warn_unused_result__|_GL_ATTRIBUTE_NODISCARD|g' \
+ -e 's|__glibc_likely|_GL_LIKELY|g' \
+ -e 's|__glibc_unlikely|_GL_UNLIKELY|g' \
+ < $(srcdir)/malloc/dynarray-skeleton.c; \
+ } > $@-t && \
+ mv $@-t $@
+MOSTLYCLEANFILES += malloc/dynarray-skeleton.gl.h malloc/dynarray-skeleton.gl.h-t
+
lib_SOURCES += malloc/dynarray_at_failure.c \
malloc/dynarray_emplace_enlarge.c \
malloc/dynarray_finalize.c \
--
2.7.4
[-- Attachment #3: 0002-scratch_buffer-Avoid-conflict-with-prepr.-macros-own.patch --]
[-- Type: text/x-patch, Size: 3597 bytes --]
From 469f9f3685c4026e79ccc8f3fb35c3eb25fd3716 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Mon, 7 Jun 2021 00:56:50 +0200
Subject: [PATCH 2/3] scratch_buffer: Avoid conflict with prepr. macros owned
by the system.
* lib/scratch_buffer.h: Don't include <libc-config.h>. Define
_GL_LIKELY, _GL_UNLIKELY. Include malloc/scratch_buffer.gl.h instead of
malloc/scratch_buffer.h.
* modules/scratch_buffer (Depends-on): Add builtin-expect.
(Makefile.am): Arrange to create malloc/scratch_buffer.gl.h from
malloc/scratch_buffer.h.
---
ChangeLog | 10 ++++++++++
lib/scratch_buffer.h | 10 +++++++---
modules/scratch_buffer | 15 +++++++++++++++
3 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index b354ff0..16132b1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
2021-06-06 Bruno Haible <bruno@clisp.org>
+ scratch_buffer: Avoid conflict with prepr. macros owned by the system.
+ * lib/scratch_buffer.h: Don't include <libc-config.h>. Define
+ _GL_LIKELY, _GL_UNLIKELY. Include malloc/scratch_buffer.gl.h instead of
+ malloc/scratch_buffer.h.
+ * modules/scratch_buffer (Depends-on): Add builtin-expect.
+ (Makefile.am): Arrange to create malloc/scratch_buffer.gl.h from
+ malloc/scratch_buffer.h.
+
+2021-06-06 Bruno Haible <bruno@clisp.org>
+
dynarray: Avoid conflict with preprocessor macros owned by the system.
* lib/dynarray.h: Don't include <libc-config.h>. Define _GL_LIKELY,
_GL_UNLIKELY. Include malloc/dynarray.gl.h instead of malloc/dynarray.h.
diff --git a/lib/scratch_buffer.h b/lib/scratch_buffer.h
index 7bb6fe8..8873577 100644
--- a/lib/scratch_buffer.h
+++ b/lib/scratch_buffer.h
@@ -110,14 +110,18 @@ extern void *scratch_buffer_dupfree (struct scratch_buffer *buffer,
/* The implementation is imported from glibc. */
-#include <libc-config.h>
-
/* Avoid possible conflicts with symbols exported by the GNU libc. */
#define __libc_scratch_buffer_dupfree gl_scratch_buffer_dupfree
#define __libc_scratch_buffer_grow gl_scratch_buffer_grow
#define __libc_scratch_buffer_grow_preserve gl_scratch_buffer_grow_preserve
#define __libc_scratch_buffer_set_array_size gl_scratch_buffer_set_array_size
-#include <malloc/scratch_buffer.h>
+#ifndef _GL_LIKELY
+/* Rely on __builtin_expect, as provided by the module 'builtin-expect'. */
+# define _GL_LIKELY(cond) __builtin_expect ((cond), 1)
+# define _GL_UNLIKELY(cond) __builtin_expect ((cond), 0)
+#endif
+
+#include <malloc/scratch_buffer.gl.h>
#endif /* _GL_SCRATCH_BUFFER_H */
diff --git a/modules/scratch_buffer b/modules/scratch_buffer
index cf83ab5..ede77a9 100644
--- a/modules/scratch_buffer
+++ b/modules/scratch_buffer
@@ -11,6 +11,7 @@ lib/malloc/scratch_buffer_set_array_size.c
Depends-on:
c99
+builtin-expect
libc-config
stdbool
stddef
@@ -21,6 +22,20 @@ free-posix
configure.ac:
Makefile.am:
+BUILT_SOURCES += malloc/scratch_buffer.gl.h
+
+malloc/scratch_buffer.gl.h: malloc/scratch_buffer.h
+ $(AM_V_GEN)rm -f $@-t $@ && \
+ { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+ sed -e 's|__always_inline|inline _GL_ATTRIBUTE_ALWAYS_INLINE|g' \
+ -e 's|__glibc_likely|_GL_LIKELY|g' \
+ -e 's|__glibc_unlikely|_GL_UNLIKELY|g' \
+ -e '/libc_hidden_proto/d' \
+ < $(srcdir)/malloc/scratch_buffer.h; \
+ } > $@-t && \
+ mv $@-t $@
+MOSTLYCLEANFILES += malloc/scratch_buffer.gl.h malloc/scratch_buffer.gl.h-t
+
lib_SOURCES += malloc/scratch_buffer_dupfree.c \
malloc/scratch_buffer_grow.c \
malloc/scratch_buffer_grow_preserve.c \
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: dynarray, scratch_buffer: Avoid conflict with preprocessor macros owned by the system
2021-06-06 23:22 ` dynarray, scratch_buffer: " Bruno Haible
@ 2021-06-08 0:41 ` Bruno Haible
0 siblings, 0 replies; 3+ messages in thread
From: Bruno Haible @ 2021-06-08 0:41 UTC (permalink / raw)
To: bug-gnulib
Oops, I forgot to 'mkdir -p malloc' in the build directory. In some
environments, the Makefile's 'dirstamp' handling does it automatically;
in others, it doesn't.
2021-06-07 Bruno Haible <bruno@clisp.org>
dynarray, scratch_buffer: Fix VPATH builds (regression from yesterday).
* modules/dynarray (configure.ac): Invoke AC_PROG_MKDIR_P.
(Makefile.am): Create malloc/ directory before creating
malloc/dynarray.gl.h and malloc/dynarray-skeleton.gl.h.
* modules/scratch_buffer (configure.ac): Invoke AC_PROG_MKDIR_P.
(Makefile.am): Create malloc/ directory before creating
malloc/scratch_buffer.gl.h.
diff --git a/modules/dynarray b/modules/dynarray
index 7fd444f..fa608de 100644
--- a/modules/dynarray
+++ b/modules/dynarray
@@ -20,11 +20,13 @@ stddef
intprops
configure.ac:
+AC_PROG_MKDIR_P
Makefile.am:
BUILT_SOURCES += malloc/dynarray.gl.h malloc/dynarray-skeleton.gl.h
malloc/dynarray.gl.h: malloc/dynarray.h
+ $(AM_V_at)$(MKDIR_P) malloc
$(AM_V_GEN)rm -f $@-t $@ && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
sed -e '/libc_hidden_proto/d' < $(srcdir)/malloc/dynarray.h; \
@@ -33,6 +35,7 @@ malloc/dynarray.gl.h: malloc/dynarray.h
MOSTLYCLEANFILES += malloc/dynarray.gl.h malloc/dynarray.gl.h-t
malloc/dynarray-skeleton.gl.h: malloc/dynarray-skeleton.c
+ $(AM_V_at)$(MKDIR_P) malloc
$(AM_V_GEN)rm -f $@-t $@ && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
sed -e 's|<malloc/dynarray\.h>|<malloc/dynarray.gl.h>|g' \
diff --git a/modules/scratch_buffer b/modules/scratch_buffer
index ede77a9..184f0b6 100644
--- a/modules/scratch_buffer
+++ b/modules/scratch_buffer
@@ -20,11 +20,13 @@ realloc-posix
free-posix
configure.ac:
+AC_PROG_MKDIR_P
Makefile.am:
BUILT_SOURCES += malloc/scratch_buffer.gl.h
malloc/scratch_buffer.gl.h: malloc/scratch_buffer.h
+ $(AM_V_at)$(MKDIR_P) malloc
$(AM_V_GEN)rm -f $@-t $@ && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
sed -e 's|__always_inline|inline _GL_ATTRIBUTE_ALWAYS_INLINE|g' \
^ permalink raw reply related [flat|nested] 3+ messages in thread
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