bpo-11410: Standardize and use symbol visibility attributes across POSIX and Windows. (GH-16347)

This commit is contained in:
Vinay Sajip 2019-10-15 08:26:12 +01:00 committed by GitHub
parent 4d202281c1
commit 0b60f64e43
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GPG Key ID: 4AEE18F83AFDEB23
12 changed files with 132 additions and 35 deletions

30
Include/exports.h Normal file
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@ -0,0 +1,30 @@
#ifndef Py_EXPORTS_H
#define Py_EXPORTS_H
#if defined(_WIN32) || defined(__CYGWIN__)
#define Py_IMPORTED_SYMBOL __declspec(dllimport)
#define Py_EXPORTED_SYMBOL __declspec(dllexport)
#define Py_LOCAL_SYMBOL
#else
/*
* If we only ever used gcc >= 5, we could use __has_attribute(visibility)
* as a cross-platform way to determine if visibility is supported. However,
* we may still need to support gcc >= 4, as some Ubuntu LTS and Centos versions
* have 4 < gcc < 5.
*/
#ifndef __has_attribute
#define __has_attribute(x) 0 // Compatibility with non-clang compilers.
#endif
#if (defined(__GNUC__) && (__GNUC__ >= 4)) ||\
(defined(__clang__) && __has_attribute(visibility))
#define Py_IMPORTED_SYMBOL __attribute__ ((visibility ("default")))
#define Py_EXPORTED_SYMBOL __attribute__ ((visibility ("default")))
#define Py_LOCAL_SYMBOL __attribute__ ((visibility ("hidden")))
#else
#define Py_IMPORTED_SYMBOL
#define Py_EXPORTED_SYMBOL
#define Py_LOCAL_SYMBOL
#endif
#endif
#endif /* Py_EXPORTS_H */

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@ -638,16 +638,18 @@ extern char * _getpty(int *, int, mode_t, int);
# define HAVE_DECLSPEC_DLL
#endif
#include "exports.h"
/* only get special linkage if built as shared or platform is Cygwin */
#if defined(Py_ENABLE_SHARED) || defined(__CYGWIN__)
# if defined(HAVE_DECLSPEC_DLL)
# if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
# define PyAPI_FUNC(RTYPE) __declspec(dllexport) RTYPE
# define PyAPI_DATA(RTYPE) extern __declspec(dllexport) RTYPE
# define PyAPI_FUNC(RTYPE) Py_EXPORTED_SYMBOL RTYPE
# define PyAPI_DATA(RTYPE) extern Py_EXPORTED_SYMBOL RTYPE
/* module init functions inside the core need no external linkage */
/* except for Cygwin to handle embedding */
# if defined(__CYGWIN__)
# define PyMODINIT_FUNC __declspec(dllexport) PyObject*
# define PyMODINIT_FUNC Py_EXPORTED_SYMBOL PyObject*
# else /* __CYGWIN__ */
# define PyMODINIT_FUNC PyObject*
# endif /* __CYGWIN__ */
@ -658,14 +660,14 @@ extern char * _getpty(int *, int, mode_t, int);
/* failures similar to those described at the bottom of 4.1: */
/* http://docs.python.org/extending/windows.html#a-cookbook-approach */
# if !defined(__CYGWIN__)
# define PyAPI_FUNC(RTYPE) __declspec(dllimport) RTYPE
# define PyAPI_FUNC(RTYPE) Py_IMPORTED_SYMBOL RTYPE
# endif /* !__CYGWIN__ */
# define PyAPI_DATA(RTYPE) extern __declspec(dllimport) RTYPE
# define PyAPI_DATA(RTYPE) extern Py_IMPORTED_SYMBOL RTYPE
/* module init functions outside the core must be exported */
# if defined(__cplusplus)
# define PyMODINIT_FUNC extern "C" __declspec(dllexport) PyObject*
# define PyMODINIT_FUNC extern "C" Py_EXPORTED_SYMBOL PyObject*
# else /* __cplusplus */
# define PyMODINIT_FUNC __declspec(dllexport) PyObject*
# define PyMODINIT_FUNC Py_EXPORTED_SYMBOL PyObject*
# endif /* __cplusplus */
# endif /* Py_BUILD_CORE */
# endif /* HAVE_DECLSPEC_DLL */
@ -673,16 +675,16 @@ extern char * _getpty(int *, int, mode_t, int);
/* If no external linkage macros defined by now, create defaults */
#ifndef PyAPI_FUNC
# define PyAPI_FUNC(RTYPE) RTYPE
# define PyAPI_FUNC(RTYPE) Py_EXPORTED_SYMBOL RTYPE
#endif
#ifndef PyAPI_DATA
# define PyAPI_DATA(RTYPE) extern RTYPE
# define PyAPI_DATA(RTYPE) extern Py_EXPORTED_SYMBOL RTYPE
#endif
#ifndef PyMODINIT_FUNC
# if defined(__cplusplus)
# define PyMODINIT_FUNC extern "C" PyObject*
# define PyMODINIT_FUNC extern "C" Py_EXPORTED_SYMBOL PyObject*
# else /* __cplusplus */
# define PyMODINIT_FUNC PyObject*
# define PyMODINIT_FUNC Py_EXPORTED_SYMBOL PyObject*
# endif /* __cplusplus */
#endif

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@ -0,0 +1,4 @@
Better control over symbol visibility is provided through use of the
visibility attributes available in gcc >= 4.0, provided in a uniform way
across POSIX and Windows. The POSIX build files have been updated to compile
with -fvisibility=hidden, minimising exported symbols.

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@ -4,11 +4,7 @@
#include <windows.h>
#endif
#if defined(MS_WIN32) || defined(__CYGWIN__)
#define EXPORT(x) __declspec(dllexport) x
#else
#define EXPORT(x) x
#endif
#define EXPORT(x) Py_EXPORTED_SYMBOL x
/* some functions handy for testing */

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@ -2,6 +2,8 @@
* Declarations shared between the different parts of the io module
*/
#include "exports.h"
/* ABCs */
extern PyTypeObject PyIOBase_Type;
extern PyTypeObject PyRawIOBase_Type;
@ -183,4 +185,4 @@ extern PyObject *_PyIO_str_write;
extern PyObject *_PyIO_empty_str;
extern PyObject *_PyIO_empty_bytes;
extern PyTypeObject _PyBytesIOBuffer_Type;
extern Py_EXPORTED_SYMBOL PyTypeObject _PyBytesIOBuffer_Type;

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@ -1124,7 +1124,7 @@ static PyBufferProcs bytesiobuf_as_buffer = {
(releasebufferproc) bytesiobuf_releasebuffer,
};
PyTypeObject _PyBytesIOBuffer_Type = {
Py_EXPORTED_SYMBOL PyTypeObject _PyBytesIOBuffer_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"_io._BytesIOBuffer", /*tp_name*/
sizeof(bytesiobuf), /*tp_basicsize*/

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@ -61,13 +61,14 @@ class Grammar:
def produce_graminit_c(self, writer):
writer("/* Generated by Parser/pgen */\n\n")
writer('#include "exports.h"\n')
writer('#include "grammar.h"\n')
writer("grammar _PyParser_Grammar;\n")
writer("Py_EXPORTED_SYMBOL grammar _PyParser_Grammar;\n")
self.print_dfas(writer)
self.print_labels(writer)
writer("grammar _PyParser_Grammar = {\n")
writer("Py_EXPORTED_SYMBOL grammar _PyParser_Grammar = {\n")
writer(" {n_dfas},\n".format(n_dfas=len(self.dfas)))
writer(" dfas,\n")
writer(" {{{n_labels}, labels}},\n".format(n_labels=len(self.labels)))

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@ -106,7 +106,7 @@ PyArg_Parse(PyObject *args, const char *format, ...)
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_Parse_SizeT(PyObject *args, const char *format, ...)
{
int retval;
@ -131,7 +131,7 @@ PyArg_ParseTuple(PyObject *args, const char *format, ...)
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseTuple_SizeT(PyObject *args, const char *format, ...)
{
int retval;
@ -156,7 +156,7 @@ _PyArg_ParseStack(PyObject *const *args, Py_ssize_t nargs, const char *format, .
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseStack_SizeT(PyObject *const *args, Py_ssize_t nargs, const char *format, ...)
{
int retval;
@ -182,7 +182,7 @@ PyArg_VaParse(PyObject *args, const char *format, va_list va)
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_VaParse_SizeT(PyObject *args, const char *format, va_list va)
{
va_list lva;
@ -1442,7 +1442,7 @@ PyArg_ParseTupleAndKeywords(PyObject *args,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywords_SizeT(PyObject *args,
PyObject *keywords,
const char *format,
@ -1493,7 +1493,7 @@ PyArg_VaParseTupleAndKeywords(PyObject *args,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,
PyObject *keywords,
const char *format,
@ -1519,7 +1519,7 @@ _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, ...)
{
@ -1532,7 +1532,7 @@ _PyArg_ParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywordsFast_SizeT(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, ...)
{
@ -1545,7 +1545,7 @@ _PyArg_ParseTupleAndKeywordsFast_SizeT(PyObject *args, PyObject *keywords,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseStackAndKeywords(PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames,
struct _PyArg_Parser *parser, ...)
{
@ -1558,7 +1558,7 @@ _PyArg_ParseStackAndKeywords(PyObject *const *args, Py_ssize_t nargs, PyObject *
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_ParseStackAndKeywords_SizeT(PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames,
struct _PyArg_Parser *parser, ...)
{
@ -1572,7 +1572,7 @@ _PyArg_ParseStackAndKeywords_SizeT(PyObject *const *args, Py_ssize_t nargs, PyOb
}
int
PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, va_list va)
{
@ -1586,7 +1586,7 @@ _PyArg_VaParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
return retval;
}
int
PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywordsFast_SizeT(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, va_list va)
{

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@ -1,7 +1,8 @@
/* Generated by Parser/pgen */
#include "exports.h"
#include "grammar.h"
grammar _PyParser_Grammar;
Py_EXPORTED_SYMBOL grammar _PyParser_Grammar;
static const arc arcs_0_0[3] = {
{2, 1},
{3, 2},
@ -2693,7 +2694,7 @@ static const label labels[183] = {
{346, 0},
{347, 0},
};
grammar _PyParser_Grammar = {
Py_EXPORTED_SYMBOL grammar _PyParser_Grammar = {
92,
dfas,
{183, labels},

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@ -57,7 +57,7 @@ _Py_static_string(PyId_string, "<string>");
extern "C" {
#endif
extern grammar _PyParser_Grammar; /* From graminit.c */
extern Py_EXPORTED_SYMBOL grammar _PyParser_Grammar; /* From graminit.c */
/* Forward */
static void flush_io(void);

41
configure vendored
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@ -7341,6 +7341,47 @@ $as_echo "$ac_cv_enable_implicit_function_declaration_error" >&6; }
CFLAGS_NODIST="$CFLAGS_NODIST -Werror=implicit-function-declaration"
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if we can use visibility in $CC" >&5
$as_echo_n "checking if we can use visibility in $CC... " >&6; }
ac_save_cc="$CC"
CC="$CC -fvisibility=hidden"
if ${ac_cv_enable_visibility+:} false; then :
$as_echo_n "(cached) " >&6
else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
ac_cv_enable_visibility=yes
else
ac_cv_enable_visibility=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
fi
CC="$ac_save_cc"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_enable_visibility" >&5
$as_echo "$ac_cv_enable_visibility" >&6; }
if test $ac_cv_enable_visibility = yes
then
CFLAGS_NODIST="$CFLAGS_NODIST -fvisibility=hidden"
fi
# if using gcc on alpha, use -mieee to get (near) full IEEE 754
# support. Without this, treatment of subnormals doesn't follow
# the standard.

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@ -1787,6 +1787,26 @@ yes)
CFLAGS_NODIST="$CFLAGS_NODIST -Werror=implicit-function-declaration"
fi
AC_MSG_CHECKING(if we can use visibility in $CC)
ac_save_cc="$CC"
CC="$CC -fvisibility=hidden"
AC_CACHE_VAL(ac_cv_enable_visibility,
AC_COMPILE_IFELSE(
[
AC_LANG_PROGRAM([[]], [[]])
],[
ac_cv_enable_visibility=yes
],[
ac_cv_enable_visibility=no
]))
CC="$ac_save_cc"
AC_MSG_RESULT($ac_cv_enable_visibility)
if test $ac_cv_enable_visibility = yes
then
CFLAGS_NODIST="$CFLAGS_NODIST -fvisibility=hidden"
fi
# if using gcc on alpha, use -mieee to get (near) full IEEE 754
# support. Without this, treatment of subnormals doesn't follow
# the standard.