Hi, On 2017-10-12 11:03:34 -0700, Andres Freund wrote: > On 2017-10-12 13:55:07 -0400, Tom Lane wrote: > > Or, if you insist on having it, we're going to have to go the pg_restrict > > route. I don't see why that means duplicating any configure logic: on > > non-Windows we can use the autoconf probe and then write > > "#define pg_restrict restrict". > > Yea, that should work. I'll try to come up with a patch.
We can't do so unconditionally in c.h or such, because that'd again cause conflicts with __declspec(restrict) on MSVC versions that don't support restrict, because it'd require restrict to be defined empty. But it's easy to do so in configure, and then have a separate definition in pg_config.h.win32. Done so in the attached commit. It's slightly ugly to have two definitions of restrict in pg_config.h.in, but whatever. Greetings, Andres Freund
>From 0ddc96424119682cf3b68c6d8d95ea894a60817a Mon Sep 17 00:00:00 2001 From: Andres Freund <and...@anarazel.de> Date: Thu, 12 Oct 2017 15:25:38 -0700 Subject: [PATCH] Use C99 restrict via pg_restrict, rather than restrict directly. Unfortunately using 'restrict' plainly causes problems with MSVC, which supports restrict only as '__restrict'. Defining 'restrict' to '__restrict' unfortunately causes a conflict with MSVC's usage of __declspec(restrict) in headers. Therefore define pg_restrict to the appropriate keyword instead, and replace existing usages. This replaces the temporary workaround introduced in 36b4b91ba078. Author: Andres Freund Discussion: https://postgr.es/m/2656.1507830...@sss.pgh.pa.us --- configure | 107 ++++++++++++++++++++++++------------------ configure.in | 15 +++++- src/include/libpq/pqformat.h | 24 +++++----- src/include/pg_config.h.in | 4 ++ src/include/pg_config.h.win32 | 22 ++++----- 5 files changed, 101 insertions(+), 71 deletions(-) diff --git a/configure b/configure index 910f0fc3736..cdcb3ceb0c8 100755 --- a/configure +++ b/configure @@ -11545,52 +11545,6 @@ _ACEOF ;; esac -{ $as_echo "$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 : - $as_echo_n "(cached) " >&6 -else - ac_cv_c_restrict=no - # The order here caters to the fact that C++ does not require restrict. - for ac_kw in __restrict __restrict__ _Restrict restrict; do - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -typedef int * int_ptr; - int foo (int_ptr $ac_kw ip) { - return ip[0]; - } -int -main () -{ -int s[1]; - int * $ac_kw t = s; - t[0] = 0; - return foo(t) - ; - return 0; -} -_ACEOF -if ac_fn_c_try_compile "$LINENO"; then : - ac_cv_c_restrict=$ac_kw -fi -rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext - test "$ac_cv_c_restrict" != no && break - done - -fi -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_restrict" >&5 -$as_echo "$ac_cv_c_restrict" >&6; } - - case $ac_cv_c_restrict in - restrict) ;; - no) $as_echo "#define restrict /**/" >>confdefs.h - ;; - *) cat >>confdefs.h <<_ACEOF -#define restrict $ac_cv_c_restrict -_ACEOF - ;; - esac - { $as_echo "$as_me:${as_lineno-$LINENO}: checking for printf format archetype" >&5 $as_echo_n "checking for printf format archetype... " >&6; } if ${pgac_cv_printf_archetype+:} false; then : @@ -12508,6 +12462,67 @@ $as_echo "#define LOCALE_T_IN_XLOCALE 1" >>confdefs.h fi +# MSVC doesn't cope well with defining restrict to __restrict, the +# spelling it understands, because it conflicts with +# __declspec(restrict). 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 : + $as_echo_n "(cached) " >&6 +else + ac_cv_c_restrict=no + # The order here caters to the fact that C++ does not require restrict. + for ac_kw in __restrict __restrict__ _Restrict restrict; do + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ +typedef int * int_ptr; + int foo (int_ptr $ac_kw ip) { + return ip[0]; + } +int +main () +{ +int s[1]; + int * $ac_kw t = s; + t[0] = 0; + return foo(t) + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + ac_cv_c_restrict=$ac_kw +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + test "$ac_cv_c_restrict" != no && break + done + +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_restrict" >&5 +$as_echo "$ac_cv_c_restrict" >&6; } + + case $ac_cv_c_restrict in + restrict) ;; + no) $as_echo "#define restrict /**/" >>confdefs.h + ;; + *) cat >>confdefs.h <<_ACEOF +#define restrict $ac_cv_c_restrict +_ACEOF + ;; + esac + +if test "$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 cmsgcred" "ac_cv_type_struct_cmsgcred" "#include <sys/socket.h> #include <sys/param.h> #ifdef HAVE_SYS_UCRED_H diff --git a/configure.in b/configure.in index ab990d69f4c..32bb7bf940d 100644 --- a/configure.in +++ b/configure.in @@ -1299,7 +1299,6 @@ fi m4_defun([AC_PROG_CC_STDC], []) dnl We don't want that. AC_C_BIGENDIAN AC_C_INLINE -AC_C_RESTRICT PGAC_PRINTF_ARCHETYPE AC_C_FLEXIBLE_ARRAY_MEMBER PGAC_C_SIGNED @@ -1326,6 +1325,20 @@ AC_TYPE_LONG_LONG_INT PGAC_TYPE_LOCALE_T +# MSVC doesn't cope well with defining restrict to __restrict, the +# spelling it understands, because it conflicts with +# __declspec(restrict). 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 cmsgcred], [], [], [#include <sys/socket.h> #include <sys/param.h> diff --git a/src/include/libpq/pqformat.h b/src/include/libpq/pqformat.h index 2329669b085..35cdee7b76f 100644 --- a/src/include/libpq/pqformat.h +++ b/src/include/libpq/pqformat.h @@ -38,8 +38,8 @@ extern void pq_sendfloat8(StringInfo buf, float8 f); * Append a 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 - * assumption that buf, buf->len, buf->data and *buf->data don't + * 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_writeint* calls. * @@ -47,12 +47,12 @@ extern void pq_sendfloat8(StringInfo buf, float8 f); * overly picky and demanding a * before a restrict. */ static inline void -pq_writeint8(StringInfoData * restrict buf, int8 i) +pq_writeint8(StringInfoData *pg_restrict buf, int8 i) { int8 ni = i; Assert(buf->len + sizeof(i) <= buf->maxlen); - memcpy((char *restrict) (buf->data + buf->len), &ni, sizeof(ni)); + memcpy((char *pg_restrict) (buf->data + buf->len), &ni, sizeof(ni)); buf->len += sizeof(i); } @@ -61,12 +61,12 @@ pq_writeint8(StringInfoData * restrict buf, int8 i) * preallocated. */ static inline void -pq_writeint16(StringInfoData * restrict buf, int16 i) +pq_writeint16(StringInfoData *pg_restrict buf, int16 i) { int16 ni = pg_hton16(i); Assert(buf->len + sizeof(ni) <= buf->maxlen); - memcpy((char *restrict) (buf->data + buf->len), &ni, sizeof(i)); + memcpy((char *pg_restrict) (buf->data + buf->len), &ni, sizeof(i)); buf->len += sizeof(i); } @@ -75,12 +75,12 @@ pq_writeint16(StringInfoData * restrict buf, int16 i) * preallocated. */ static inline void -pq_writeint32(StringInfoData * restrict buf, int32 i) +pq_writeint32(StringInfoData *pg_restrict buf, int32 i) { int32 ni = pg_hton32(i); Assert(buf->len + sizeof(i) <= buf->maxlen); - memcpy((char *restrict) (buf->data + buf->len), &ni, sizeof(i)); + memcpy((char *pg_restrict) (buf->data + buf->len), &ni, sizeof(i)); buf->len += sizeof(i); } @@ -89,12 +89,12 @@ pq_writeint32(StringInfoData * restrict buf, int32 i) * preallocated. */ static inline void -pq_writeint64(StringInfoData * restrict buf, int64 i) +pq_writeint64(StringInfoData *pg_restrict buf, int64 i) { int64 ni = pg_hton64(i); Assert(buf->len + sizeof(i) <= buf->maxlen); - memcpy((char *restrict) (buf->data + buf->len), &ni, sizeof(i)); + memcpy((char *pg_restrict) (buf->data + buf->len), &ni, sizeof(i)); buf->len += sizeof(i); } @@ -109,7 +109,7 @@ pq_writeint64(StringInfoData * restrict buf, int64 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; @@ -120,7 +120,7 @@ pq_writestring(StringInfoData * restrict buf, const char *restrict str) Assert(buf->len + slen + 1 <= buf->maxlen); - memcpy(((char *restrict) buf->data + buf->len), p, slen + 1); + memcpy(((char *pg_restrict) buf->data + buf->len), p, slen + 1); buf->len += slen + 1; if (p != str) diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 80ee37dd622..cfdcc5ac62f 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -923,6 +923,10 @@ if such a type exists, and if the system does not define it. */ #undef intptr_t +/* 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. */ diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32 index 81604de7f92..ab9b941e89d 100644 --- a/src/include/pg_config.h.win32 +++ b/src/include/pg_config.h.win32 @@ -681,21 +681,19 @@ #define inline __inline #endif +/* Define to keyword to use for C99 restrict support, or to nothing if this is + not supported */ +/* Works for C and C++ in Visual Studio 2008 and upwards */ +#if (_MSC_VER >= 1500) +#define pg_restrict __restrict +#else +#define pg_restrict +#endif + /* 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. */ -/* Visual Studio 2008 and upwards */ -#if (_MSC_VER >= 1500) -/* works for C and C++ in msvc */ -/* - * Temporary attempt at a workaround for stdlib.h's use of - * declspec(restrict), conflicting with below define. - */ -#include <stdlib.h> -#define restrict __restrict -#else -#define restrict -#endif +/* not defined, because it'd conflict with __declspec(restrict) */ /* Define to empty if the C compiler does not understand signed types. */ /* #undef signed */ -- 2.14.1.536.g6867272d5b.dirty
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