bpo-11410: Standardize and use symbol visibility attributes across POSIX and Windows. (GH-16347)
diff --git a/Include/exports.h b/Include/exports.h
new file mode 100644
index 0000000..fc1a5c5
--- /dev/null
+++ b/Include/exports.h
@@ -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 */
diff --git a/Include/pyport.h b/Include/pyport.h
index 51967d1..64c73f0 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -638,16 +638,18 @@
# 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 @@
/* 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 @@
/* 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
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-09-24-05-32-27.bpo-11410.vS182p.rst b/Misc/NEWS.d/next/Core and Builtins/2019-09-24-05-32-27.bpo-11410.vS182p.rst
new file mode 100644
index 0000000..2b572ad
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-09-24-05-32-27.bpo-11410.vS182p.rst
@@ -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.
diff --git a/Modules/_ctypes/_ctypes_test.c b/Modules/_ctypes/_ctypes_test.c
index 8a0e5e9..40da652 100644
--- a/Modules/_ctypes/_ctypes_test.c
+++ b/Modules/_ctypes/_ctypes_test.c
@@ -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 */
diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index 4d318ac..a8f3951 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -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_empty_str;
extern PyObject *_PyIO_empty_bytes;
-extern PyTypeObject _PyBytesIOBuffer_Type;
+extern Py_EXPORTED_SYMBOL PyTypeObject _PyBytesIOBuffer_Type;
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index a5f4c47..b5d308a 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -1124,7 +1124,7 @@
(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*/
diff --git a/Parser/pgen/grammar.py b/Parser/pgen/grammar.py
index 56188db..ce40e16 100644
--- a/Parser/pgen/grammar.py
+++ b/Parser/pgen/grammar.py
@@ -61,13 +61,14 @@
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)))
diff --git a/Python/getargs.c b/Python/getargs.c
index 7723ae3..0ca0862 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -106,7 +106,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_Parse_SizeT(PyObject *args, const char *format, ...)
{
int retval;
@@ -131,7 +131,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_ParseTuple_SizeT(PyObject *args, const char *format, ...)
{
int retval;
@@ -156,7 +156,7 @@
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 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_VaParse_SizeT(PyObject *args, const char *format, va_list va)
{
va_list lva;
@@ -1442,7 +1442,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywords_SizeT(PyObject *args,
PyObject *keywords,
const char *format,
@@ -1493,7 +1493,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,
PyObject *keywords,
const char *format,
@@ -1519,7 +1519,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, ...)
{
@@ -1532,7 +1532,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_ParseTupleAndKeywordsFast_SizeT(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, ...)
{
@@ -1545,7 +1545,7 @@
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 @@
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 @@
}
-int
+PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywordsFast(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, va_list va)
{
@@ -1586,7 +1586,7 @@
return retval;
}
-int
+PyAPI_FUNC(int)
_PyArg_VaParseTupleAndKeywordsFast_SizeT(PyObject *args, PyObject *keywords,
struct _PyArg_Parser *parser, va_list va)
{
diff --git a/Python/graminit.c b/Python/graminit.c
index 7c40ce9..62d9ae2 100644
--- a/Python/graminit.c
+++ b/Python/graminit.c
@@ -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 @@
{346, 0},
{347, 0},
};
-grammar _PyParser_Grammar = {
+Py_EXPORTED_SYMBOL grammar _PyParser_Grammar = {
92,
dfas,
{183, labels},
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 6089086..7025058 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -57,7 +57,7 @@
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);
diff --git a/configure b/configure
index f1979c1..4f094ea 100755
--- a/configure
+++ b/configure
@@ -7341,6 +7341,47 @@
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.
diff --git a/configure.ac b/configure.ac
index 917a908..8de5340 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1787,6 +1787,26 @@
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.