From 71d8775feeb647ae5003cfd466de7b58cd1bf269 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Wed, 25 May 2022 14:21:36 +0200 Subject: [PATCH] gh-93202: Always use %zd printf formatter (#93201) Python now always use the ``%zu`` and ``%zd`` printf formats to format a size_t or Py_ssize_t number. Building Python 3.12 requires a C11 compiler, so these printf formats are now always supported. * PyObject_Print() and _PyObject_Dump() now use the printf %zd format to display an object reference count. * Update PY_FORMAT_SIZE_T comment. * Remove outdated notes about the %zd format in PyBytes_FromFormat() and PyUnicode_FromFormat() documentations. * configure no longer checks for the %zd format and no longer defines PY_FORMAT_SIZE_T macro in pyconfig.h. * pymacconfig.h no longer undefines PY_FORMAT_SIZE_T: macOS 10.4 is no longer supported. Python 3.12 now requires macOS 10.6 (Snow Leopard) or newer. --- Doc/c-api/bytes.rst | 3 - Doc/c-api/unicode.rst | 4 -- Include/pymacconfig.h | 12 ---- Include/pyport.h | 28 +------- ...2-05-25-05-46-00.gh-issue-93202.T37jtj.rst | 4 ++ Modules/_ctypes/_ctypes.c | 4 +- Objects/object.c | 9 +-- configure | 66 ------------------- configure.ac | 46 ------------- pyconfig.h.in | 3 - 10 files changed, 11 insertions(+), 168 deletions(-) create mode 100644 Misc/NEWS.d/next/Build/2022-05-25-05-46-00.gh-issue-93202.T37jtj.rst diff --git a/Doc/c-api/bytes.rst b/Doc/c-api/bytes.rst index 7617487a462..d62962cab45 100644 --- a/Doc/c-api/bytes.rst +++ b/Doc/c-api/bytes.rst @@ -58,9 +58,6 @@ called with a non-bytes parameter. .. % XXX: This should be exactly the same as the table in PyErr_Format. .. % One should just refer to the other. - .. % XXX: The descriptions for %zd and %zu are wrong, but the truth is complicated - .. % because not all compilers support the %z width modifier -- we fake it - .. % when necessary via interpolating PY_FORMAT_SIZE_T. .. tabularcolumns:: |l|l|L| diff --git a/Doc/c-api/unicode.rst b/Doc/c-api/unicode.rst index abcf0cd6c87..5d420bfa93c 100644 --- a/Doc/c-api/unicode.rst +++ b/Doc/c-api/unicode.rst @@ -397,10 +397,6 @@ APIs: ASCII-encoded string. The following format characters are allowed: .. % This should be exactly the same as the table in PyErr_Format. - .. % The descriptions for %zd and %zu are wrong, but the truth is complicated - .. % because not all compilers support the %z width modifier -- we fake it - .. % when necessary via interpolating PY_FORMAT_SIZE_T. - .. % Similar comments apply to the %ll width modifier and .. tabularcolumns:: |l|l|L| diff --git a/Include/pymacconfig.h b/Include/pymacconfig.h index 9dde11bd58e..00459a03b98 100644 --- a/Include/pymacconfig.h +++ b/Include/pymacconfig.h @@ -84,18 +84,6 @@ # define HAVE_GCC_ASM_FOR_X87 #endif - /* - * The definition in pyconfig.h is only valid on the OS release - * where configure ran on and not necessarily for all systems where - * the executable can be used on. - * - * Specifically: OSX 10.4 has limited supported for '%zd', while - * 10.5 has full support for '%zd'. A binary built on 10.5 won't - * work properly on 10.4 unless we suppress the definition - * of PY_FORMAT_SIZE_T - */ -#undef PY_FORMAT_SIZE_T - #endif /* defined(_APPLE__) */ diff --git a/Include/pyport.h b/Include/pyport.h index 086ed4204e4..8e676378911 100644 --- a/Include/pyport.h +++ b/Include/pyport.h @@ -186,32 +186,10 @@ typedef Py_ssize_t Py_ssize_clean_t; /* Largest possible value of size_t. */ #define PY_SIZE_MAX SIZE_MAX -/* Macro kept for backward compatibility: use "z" in new code. +/* Macro kept for backward compatibility: use directly "z" in new code. * - * PY_FORMAT_SIZE_T is a platform-specific modifier for use in a printf - * format to convert an argument with the width of a size_t or Py_ssize_t. - * C99 introduced "z" for this purpose, but old MSVCs had not supported it. - * Since MSVC supports "z" since (at least) 2015, we can just use "z" - * for new code. - * - * These "high level" Python format functions interpret "z" correctly on - * all platforms (Python interprets the format string itself, and does whatever - * the platform C requires to convert a size_t/Py_ssize_t argument): - * - * PyBytes_FromFormat - * PyErr_Format - * PyBytes_FromFormatV - * PyUnicode_FromFormatV - * - * Lower-level uses require that you interpolate the correct format modifier - * yourself (e.g., calling printf, fprintf, sprintf, PyOS_snprintf); for - * example, - * - * Py_ssize_t index; - * fprintf(stderr, "index %" PY_FORMAT_SIZE_T "d sucks\n", index); - * - * That will expand to %zd or to something else correct for a Py_ssize_t on - * the platform. + * PY_FORMAT_SIZE_T is a modifier for use in a printf format to convert an + * argument with the width of a size_t or Py_ssize_t: "z" (C99). */ #ifndef PY_FORMAT_SIZE_T # define PY_FORMAT_SIZE_T "z" diff --git a/Misc/NEWS.d/next/Build/2022-05-25-05-46-00.gh-issue-93202.T37jtj.rst b/Misc/NEWS.d/next/Build/2022-05-25-05-46-00.gh-issue-93202.T37jtj.rst new file mode 100644 index 00000000000..6018e400c15 --- /dev/null +++ b/Misc/NEWS.d/next/Build/2022-05-25-05-46-00.gh-issue-93202.T37jtj.rst @@ -0,0 +1,4 @@ +Python now always use the ``%zu`` and ``%zd`` printf formats to format a +``size_t`` or ``Py_ssize_t`` number. Building Python 3.12 requires a C11 +compiler, so these printf formats are now always supported. Patch by Victor +Stinner. diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c index d6fa11d3481..2c629d76beb 100644 --- a/Modules/_ctypes/_ctypes.c +++ b/Modules/_ctypes/_ctypes.c @@ -396,9 +396,9 @@ _ctypes_alloc_format_string_with_shape(int ndim, const Py_ssize_t *shape, strcat(new_prefix, "("); for (k = 0; k < ndim; ++k) { if (k < ndim-1) { - sprintf(buf, "%"PY_FORMAT_SIZE_T"d,", shape[k]); + sprintf(buf, "%zd,", shape[k]); } else { - sprintf(buf, "%"PY_FORMAT_SIZE_T"d)", shape[k]); + sprintf(buf, "%zd)", shape[k]); } strcat(new_prefix, buf); } diff --git a/Objects/object.c b/Objects/object.c index 95045ed03d5..49b1cba89b1 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -274,11 +274,8 @@ PyObject_Print(PyObject *op, FILE *fp, int flags) } else { if (Py_REFCNT(op) <= 0) { - /* XXX(twouters) cast refcount to long until %zd is - universally available */ Py_BEGIN_ALLOW_THREADS - fprintf(fp, "", - (long)Py_REFCNT(op), (void *)op); + fprintf(fp, "", Py_REFCNT(op), (void *)op); Py_END_ALLOW_THREADS } else { @@ -371,9 +368,7 @@ _PyObject_Dump(PyObject* op) /* first, write fields which are the least likely to crash */ fprintf(stderr, "object address : %p\n", (void *)op); - /* XXX(twouters) cast refcount to long until %zd is - universally available */ - fprintf(stderr, "object refcount : %ld\n", (long)Py_REFCNT(op)); + fprintf(stderr, "object refcount : %zd\n", Py_REFCNT(op)); fflush(stderr); PyTypeObject *type = Py_TYPE(op); diff --git a/configure b/configure index 6fa4051310b..c72fc4afdb9 100755 --- a/configure +++ b/configure @@ -21150,72 +21150,6 @@ then LIBS="$LIBS -framework CoreFoundation" fi -{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for %zd printf() format support" >&5 -$as_echo_n "checking for %zd printf() format support... " >&6; } -if ${ac_cv_have_size_t_format+:} false; then : - $as_echo_n "(cached) " >&6 -else - if test "$cross_compiling" = yes; then : - ac_cv_have_size_t_format="cross -- assuming yes" - -else - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ - -#include -#include -#include - -#ifdef HAVE_SYS_TYPES_H -#include -#endif - -#ifdef HAVE_SSIZE_T -typedef ssize_t Py_ssize_t; -#elif SIZEOF_VOID_P == SIZEOF_LONG -typedef long Py_ssize_t; -#else -typedef int Py_ssize_t; -#endif - -int main() -{ - char buffer[256]; - - if(sprintf(buffer, "%zd", (size_t)123) < 0) - return 1; - - if (strcmp(buffer, "123")) - return 1; - - if (sprintf(buffer, "%zd", (Py_ssize_t)-123) < 0) - return 1; - - if (strcmp(buffer, "-123")) - return 1; - - return 0; -} - -_ACEOF -if ac_fn_c_try_run "$LINENO"; then : - ac_cv_have_size_t_format=yes -else - ac_cv_have_size_t_format=no -fi -rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \ - conftest.$ac_objext conftest.beam conftest.$ac_ext -fi - -fi -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_have_size_t_format" >&5 -$as_echo "$ac_cv_have_size_t_format" >&6; } -if test "$ac_cv_have_size_t_format" != no ; then - -$as_echo "#define PY_FORMAT_SIZE_T \"z\"" >>confdefs.h - -fi - ac_fn_c_check_type "$LINENO" "socklen_t" "ac_cv_type_socklen_t" " #ifdef HAVE_SYS_TYPES_H #include diff --git a/configure.ac b/configure.ac index bef4904325b..a8d499df2f1 100644 --- a/configure.ac +++ b/configure.ac @@ -6004,52 +6004,6 @@ then LIBS="$LIBS -framework CoreFoundation" fi -AC_CACHE_CHECK([for %zd printf() format support], ac_cv_have_size_t_format, [dnl -AC_RUN_IFELSE([AC_LANG_SOURCE([[ -#include -#include -#include - -#ifdef HAVE_SYS_TYPES_H -#include -#endif - -#ifdef HAVE_SSIZE_T -typedef ssize_t Py_ssize_t; -#elif SIZEOF_VOID_P == SIZEOF_LONG -typedef long Py_ssize_t; -#else -typedef int Py_ssize_t; -#endif - -int main() -{ - char buffer[256]; - - if(sprintf(buffer, "%zd", (size_t)123) < 0) - return 1; - - if (strcmp(buffer, "123")) - return 1; - - if (sprintf(buffer, "%zd", (Py_ssize_t)-123) < 0) - return 1; - - if (strcmp(buffer, "-123")) - return 1; - - return 0; -} -]])], - [ac_cv_have_size_t_format=yes], - [ac_cv_have_size_t_format=no], - [ac_cv_have_size_t_format="cross -- assuming yes" -])]) -if test "$ac_cv_have_size_t_format" != no ; then - AC_DEFINE(PY_FORMAT_SIZE_T, "z", - [Define to printf format modifier for Py_ssize_t]) -fi - AC_CHECK_TYPE(socklen_t,, AC_DEFINE(socklen_t,int, [Define to `int' if does not define.]),[ diff --git a/pyconfig.h.in b/pyconfig.h.in index 383fd47dd43..b244ed233d6 100644 --- a/pyconfig.h.in +++ b/pyconfig.h.in @@ -1506,9 +1506,6 @@ /* Define if you want to coerce the C locale to a UTF-8 based locale */ #undef PY_COERCE_C_LOCALE -/* Define to printf format modifier for Py_ssize_t */ -#undef PY_FORMAT_SIZE_T - /* Define to 1 to build the sqlite module with loadable extensions support. */ #undef PY_SQLITE_ENABLE_LOAD_EXTENSION