postgres.git / summary / log / commit / refs
commit fa16e7fd84886643f480c36614fa11d45fc6d26f
Author: Peter Eisentraut <peter@eisentraut.org>
Date: Wed Jan 14 14:12:25 2026 +0000
Revert "Replace pg_restrict by standard restrict"
This reverts commit f0f2c0c1aef95757c4e7f144d5577e2b0d814279.
The original problem that led to the use of pg_restrict was that MSVC
couldn't handle plain restrict, and defining it to something else
would conflict with its __declspec(restrict) that is used in system
header files. In C11 mode, this is no longer a problem, as MSVC
handles plain restrict. This led to the commit to replace pg_restrict
with restrict. But this did not take C++ into account. Standard C++
does not have restrict, so we defined it as something else (for
example, MSVC supports __restrict). But this then again conflicts
with __declspec(restrict) in system header files. So we have to
revert this attempt. The comments are updated to clarify that the
reason for this is now C++ only.
Reported-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/CAGECzQRoD7chJP1-dneSrhxUJv%2BBRcigoGOO4UwGzaShLot2Yw%40mail.gmail.com
configure | 18 ++++++++++++++----
configure.ac | 16 ++++++++++++----
meson.build | 13 +++++++------
src/bin/pg_verifybackup/pg_verifybackup.c | 4 ++--
src/bin/pg_verifybackup/pg_verifybackup.h | 4 ++--
src/common/logging.c | 4 ++--
src/common/string.c | 2 +-
src/include/c.h | 6 ------
src/include/common/logging.h | 4 ++--
src/include/common/string.h | 2 +-
src/include/libpq/pqformat.h | 12 ++++++------
src/include/pg_config.h.in | 4 ++++
12 files changed, 53 insertions(+), 36 deletions(-)
diff --git a/configure b/configure
index 045c913865d..fb6a4914b06 100755
--- a/configure
+++ b/configure
@@ -15131,10 +15131,10 @@ _ACEOF
fi
-# Even though restrict is in C99 and should be supported by all
-# supported compilers, this test is useful because it will prefer a
-# spelling that also works in C++ (often __restrict). (restrict is
-# not part of the C++ standard.)
+# MSVC doesn't cope well with defining restrict to __restrict, the
+# spelling it understands, because it conflicts with
+# __declspec(restrict) in C++ mode. Therefore we define pg_restrict to
+# the appropriate definition, which presumably won't conflict.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C/C++ restrict keyword" >&5
$as_echo_n "checking for C/C++ restrict keyword... " >&6; }
if ${ac_cv_c_restrict+:} false; then :
@@ -15181,6 +15181,16 @@ _ACEOF
;;
esac
+if test "$ac_cv_c_restrict" = "no"; then
+ pg_restrict=""
+else
+ pg_restrict="$ac_cv_c_restrict"
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define pg_restrict $pg_restrict
+_ACEOF
+
ac_fn_c_check_type "$LINENO" "struct option" "ac_cv_type_struct_option" "#ifdef HAVE_GETOPT_H
#include <getopt.h>
diff --git a/configure.ac b/configure.ac
index 145197e6bd6..d3febfe58f1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1687,11 +1687,19 @@ PGAC_UNION_SEMUN
AC_CHECK_TYPES(socklen_t, [], [], [#include <sys/socket.h>])
PGAC_STRUCT_SOCKADDR_SA_LEN
-# Even though restrict is in C99 and should be supported by all
-# supported compilers, this test is useful because it will prefer a
-# spelling that also works in C++ (often __restrict). (restrict is
-# not part of the C++ standard.)
+# MSVC doesn't cope well with defining restrict to __restrict, the
+# spelling it understands, because it conflicts with
+# __declspec(restrict) in C++ mode. Therefore we define pg_restrict to
+# the appropriate definition, which presumably won't conflict.
AC_C_RESTRICT
+if test "$ac_cv_c_restrict" = "no"; then
+ pg_restrict=""
+else
+ pg_restrict="$ac_cv_c_restrict"
+fi
+AC_DEFINE_UNQUOTED([pg_restrict], [$pg_restrict],
+[Define to keyword to use for C99 restrict support, or to nothing if not
+supported])
AC_CHECK_TYPES([struct option], [], [],
[#ifdef HAVE_GETOPT_H
diff --git a/meson.build b/meson.build
index d8a701440da..eedd40b8137 100644
--- a/meson.build
+++ b/meson.build
@@ -2847,12 +2847,13 @@ int main(void)
endforeach
-# Even though restrict is in C99 and should be supported by all
-# supported compilers, this indirection is useful because __restrict
-# also works in C++ in all supported compilers. (If not, then we
-# might have to write a real test.) (restrict is not part of the C++
-# standard.)
-cdata.set('restrict', '__restrict')
+# MSVC doesn't cope well with defining restrict to __restrict, the
+# spelling it understands, because it conflicts with
+# __declspec(restrict) in C++ mode. Therefore we define pg_restrict
+# to the appropriate definition, which presumably won't conflict.
+#
+# We assume C99 support, so we don't need to make this conditional.
+cdata.set('pg_restrict', '__restrict')
# Most libraries are included only if they demonstrably provide a function we
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index 456e0375e13..f9f2d457f2f 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -1228,7 +1228,7 @@ parse_required_wal(verifier_context *context, char *pg_waldump_path,
* context says we should.
*/
void
-report_backup_error(verifier_context *context, const char *restrict fmt,...)
+report_backup_error(verifier_context *context, const char *pg_restrict fmt,...)
{
va_list ap;
@@ -1245,7 +1245,7 @@ report_backup_error(verifier_context *context, const char *restrict fmt,...)
* Report a fatal error and exit
*/
void
-report_fatal_error(const char *restrict fmt,...)
+report_fatal_error(const char *pg_restrict fmt,...)
{
va_list ap;
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.h b/src/bin/pg_verifybackup/pg_verifybackup.h
index 1cd76a8826b..a99d9bfd581 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.h
+++ b/src/bin/pg_verifybackup/pg_verifybackup.h
@@ -96,9 +96,9 @@ typedef struct verifier_context
} verifier_context;
extern void report_backup_error(verifier_context *context,
- const char *restrict fmt,...)
+ const char *pg_restrict fmt,...)
pg_attribute_printf(2, 3);
-pg_noreturn extern void report_fatal_error(const char *restrict fmt,...)
+pg_noreturn extern void report_fatal_error(const char *pg_restrict fmt,...)
pg_attribute_printf(1, 2);
extern bool should_ignore_relpath(verifier_context *context,
const char *relpath);
diff --git a/src/common/logging.c b/src/common/logging.c
index 214a87f2189..5206949e5d8 100644
--- a/src/common/logging.c
+++ b/src/common/logging.c
@@ -206,7 +206,7 @@ pg_logging_set_locus_callback(void (*cb) (const char **filename, uint64 *lineno)
void
pg_log_generic(enum pg_log_level level, enum pg_log_part part,
- const char *restrict fmt,...)
+ const char *pg_restrict fmt,...)
{
va_list ap;
@@ -217,7 +217,7 @@ pg_log_generic(enum pg_log_level level, enum pg_log_part part,
void
pg_log_generic_v(enum pg_log_level level, enum pg_log_part part,
- const char *restrict fmt, va_list ap)
+ const char *pg_restrict fmt, va_list ap)
{
int save_errno = errno;
const char *filename = NULL;
diff --git a/src/common/string.c b/src/common/string.c
index fff14d3facf..41c74a1502d 100644
--- a/src/common/string.c
+++ b/src/common/string.c
@@ -47,7 +47,7 @@ pg_str_endswith(const char *str, const char *end)
* strtoint --- just like strtol, but returns int not long
*/
int
-strtoint(const char *restrict str, char **restrict endptr, int base)
+strtoint(const char *pg_restrict str, char **pg_restrict endptr, int base)
{
long val;
diff --git a/src/include/c.h b/src/include/c.h
index 335af3352d1..7136102e5ff 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -108,12 +108,6 @@
#define inline
#endif
-/*
- * Previously used PostgreSQL-specific spelling, for backward compatibility
- * for extensions.
- */
-#define pg_restrict restrict
-
/*
* Attribute macros
*
diff --git a/src/include/common/logging.h b/src/include/common/logging.h
index b5caec0bff1..bccba4ac07b 100644
--- a/src/include/common/logging.h
+++ b/src/include/common/logging.h
@@ -93,10 +93,10 @@ void pg_logging_set_pre_callback(void (*cb) (void));
void pg_logging_set_locus_callback(void (*cb) (const char **filename, uint64 *lineno));
void pg_log_generic(enum pg_log_level level, enum pg_log_part part,
- const char *restrict fmt,...)
+ const char *pg_restrict fmt,...)
pg_attribute_printf(3, 4);
void pg_log_generic_v(enum pg_log_level level, enum pg_log_part part,
- const char *restrict fmt, va_list ap)
+ const char *pg_restrict fmt, va_list ap)
pg_attribute_printf(3, 0);
/*
diff --git a/src/include/common/string.h b/src/include/common/string.h
index 5e1bd61c710..2a7c31ea74e 100644
--- a/src/include/common/string.h
+++ b/src/include/common/string.h
@@ -25,7 +25,7 @@ typedef struct PromptInterruptContext
/* functions in src/common/string.c */
extern bool pg_str_endswith(const char *str, const char *end);
-extern int strtoint(const char *restrict str, char **restrict endptr,
+extern int strtoint(const char *pg_restrict str, char **pg_restrict endptr,
int base);
extern char *pg_clean_ascii(const char *str, int alloc_flags);
extern int pg_strip_crlf(char *str);
diff --git a/src/include/libpq/pqformat.h b/src/include/libpq/pqformat.h
index 911d9397f5e..bc4ab1381a9 100644
--- a/src/include/libpq/pqformat.h
+++ b/src/include/libpq/pqformat.h
@@ -34,7 +34,7 @@ extern void pq_sendfloat8(StringInfo buf, float8 f);
* Append a [u]int8 to a StringInfo buffer, which already has enough space
* preallocated.
*
- * The use of restrict allows the compiler to optimize the code based on
+ * The use of pg_restrict allows the compiler to optimize the code based on
* the assumption that buf, buf->len, buf->data and *buf->data don't
* overlap. Without the annotation buf->len etc cannot be kept in a register
* over subsequent pq_writeintN calls.
@@ -43,7 +43,7 @@ extern void pq_sendfloat8(StringInfo buf, float8 f);
* overly picky and demanding a * before a restrict.
*/
static inline void
-pq_writeint8(StringInfoData *restrict buf, uint8 i)
+pq_writeint8(StringInfoData *pg_restrict buf, uint8 i)
{
uint8 ni = i;
@@ -57,7 +57,7 @@ pq_writeint8(StringInfoData *restrict buf, uint8 i)
* preallocated.
*/
static inline void
-pq_writeint16(StringInfoData *restrict buf, uint16 i)
+pq_writeint16(StringInfoData *pg_restrict buf, uint16 i)
{
uint16 ni = pg_hton16(i);
@@ -71,7 +71,7 @@ pq_writeint16(StringInfoData *restrict buf, uint16 i)
* preallocated.
*/
static inline void
-pq_writeint32(StringInfoData *restrict buf, uint32 i)
+pq_writeint32(StringInfoData *pg_restrict buf, uint32 i)
{
uint32 ni = pg_hton32(i);
@@ -85,7 +85,7 @@ pq_writeint32(StringInfoData *restrict buf, uint32 i)
* preallocated.
*/
static inline void
-pq_writeint64(StringInfoData *restrict buf, uint64 i)
+pq_writeint64(StringInfoData *pg_restrict buf, uint64 i)
{
uint64 ni = pg_hton64(i);
@@ -105,7 +105,7 @@ pq_writeint64(StringInfoData *restrict buf, uint64 i)
* sent to the frontend.
*/
static inline void
-pq_writestring(StringInfoData *restrict buf, const char *restrict str)
+pq_writestring(StringInfoData *pg_restrict buf, const char *pg_restrict str)
{
int slen = strlen(str);
char *p;
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 10fa85e78c2..339268dc8ef 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -786,6 +786,10 @@
#undef inline
#endif
+/* Define to keyword to use for C99 restrict support, or to nothing if not
+ supported */
+#undef pg_restrict
+
/* Define to the equivalent of the C99 'restrict' keyword, or to
nothing if this is not supported. Do not define if restrict is
supported directly. */
[parent: 794ba8b6a4c8]