Use -fvisibility=hidden for shared libraries

diff --git a/configure b/configure
index 3f2aea0d7d..98eabe8b08 100755
--- a/configure
+++ b/configure
@@ -735,6 +735,8 @@ CPP
 CFLAGS_SL
 BITCODE_CXXFLAGS
 BITCODE_CFLAGS
+CXXFLAGS_SL_MOD
+CFLAGS_SL_MOD
 CFLAGS_VECTORIZE
 CFLAGS_UNROLL_LOOPS
 PERMIT_DECLARATION_AFTER_STATEMENT
@@ -6288,6 +6290,154 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
+  #
+  # If the compiler knows how to hide symbols, set CFLAGS_SL_MOD
+  # to the switch needed for that, and define HAVE_VISIBILITY_ATTRIBUTE.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MOD} -fvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MOD="${CFLAGS_SL_MOD} -fvisibility=hidden"
+fi
+
+
+  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+
+$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
+
+  fi
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MOD} -fvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MOD="${CXXFLAGS_SL_MOD} -fvisibility=hidden"
+fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MOD} -fvisibility-inlines-hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
+  CXXFLAGS_SL_MOD="${CXXFLAGS_SL_MOD} -fvisibility-inlines-hidden"
+fi
+
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
@@ -6940,6 +7090,8 @@ fi
 
 
 
+
+
 # Determine flags used to emit bitcode for JIT inlining.
 # 1. We must duplicate any behaviour-changing compiler flags used above,
 # to keep compatibility with the compiler used for normal Postgres code.
diff --git a/configure.ac b/configure.ac
index 95287705f6..b39d9c64f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -523,6 +523,17 @@ if test "$GCC" = yes -a "$ICC" = no; then
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
   #
+  # If the compiler knows how to hide symbols, set CFLAGS_SL_MOD
+  # to the switch needed for that, and define HAVE_VISIBILITY_ATTRIBUTE.
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MOD, [-fvisibility=hidden])
+  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+     AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
+               [Define to 1 if your compiler knows the visibility("hidden") attribute.])
+  fi
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MOD, [-fvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MOD, [-fvisibility-inlines-hidden])
+  #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
   # switches, so we have to test for the positive form and if that works,
@@ -576,6 +587,8 @@ fi
 
 AC_SUBST(CFLAGS_UNROLL_LOOPS)
 AC_SUBST(CFLAGS_VECTORIZE)
+AC_SUBST(CFLAGS_SL_MOD)
+AC_SUBST(CXXFLAGS_SL_MOD)
 
 # Determine flags used to emit bitcode for JIT inlining.
 # 1. We must duplicate any behaviour-changing compiler flags used above,
diff --git a/contrib/hstore/hstore.h b/contrib/hstore/hstore.h
index bf4a565ed9..625134c9f6 100644
--- a/contrib/hstore/hstore.h
+++ b/contrib/hstore/hstore.h
@@ -147,7 +147,7 @@ typedef struct
 	} while (0)
 
 /* DatumGetHStoreP includes support for reading old-format hstore values */
-extern HStore *hstoreUpgrade(Datum orig);
+extern PGDLLEXPORT HStore *hstoreUpgrade(Datum orig);
 
 #define DatumGetHStoreP(d) hstoreUpgrade(d)
 
@@ -168,14 +168,14 @@ typedef struct
 	bool		needfree;		/* need to pfree the value? */
 } Pairs;
 
-extern int	hstoreUniquePairs(Pairs *a, int32 l, int32 *buflen);
-extern HStore *hstorePairs(Pairs *pairs, int32 pcount, int32 buflen);
+extern PGDLLEXPORT int	hstoreUniquePairs(Pairs *a, int32 l, int32 *buflen);
+extern PGDLLEXPORT HStore *hstorePairs(Pairs *pairs, int32 pcount, int32 buflen);
 
-extern size_t hstoreCheckKeyLen(size_t len);
-extern size_t hstoreCheckValLen(size_t len);
+extern PGDLLEXPORT size_t hstoreCheckKeyLen(size_t len);
+extern PGDLLEXPORT size_t hstoreCheckValLen(size_t len);
 
-extern int	hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen);
-extern Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
+extern PGDLLEXPORT int	hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen);
+extern PGDLLEXPORT Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
 
 #define HStoreContainsStrategyNumber	7
 #define HStoreExistsStrategyNumber		9
@@ -194,7 +194,7 @@ extern Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
 #if HSTORE_POLLUTE_NAMESPACE
 #define HSTORE_POLLUTE(newname_,oldname_) \
 	PG_FUNCTION_INFO_V1(oldname_);		  \
-	Datum newname_(PG_FUNCTION_ARGS);	  \
+	extern PGDLLEXPORT Datum newname_(PG_FUNCTION_ARGS);	  \
 	Datum oldname_(PG_FUNCTION_ARGS) { return newname_(fcinfo); } \
 	extern int no_such_variable
 #else
diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index 5b4be5e680..d8bcdedbdb 100644
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -176,30 +176,30 @@ typedef struct
 
 
 /* use in array iterator */
-Datum		ltree_isparent(PG_FUNCTION_ARGS);
-Datum		ltree_risparent(PG_FUNCTION_ARGS);
-Datum		ltq_regex(PG_FUNCTION_ARGS);
-Datum		ltq_rregex(PG_FUNCTION_ARGS);
-Datum		lt_q_regex(PG_FUNCTION_ARGS);
-Datum		lt_q_rregex(PG_FUNCTION_ARGS);
-Datum		ltxtq_exec(PG_FUNCTION_ARGS);
-Datum		ltxtq_rexec(PG_FUNCTION_ARGS);
-Datum		_ltq_regex(PG_FUNCTION_ARGS);
-Datum		_ltq_rregex(PG_FUNCTION_ARGS);
-Datum		_lt_q_regex(PG_FUNCTION_ARGS);
-Datum		_lt_q_rregex(PG_FUNCTION_ARGS);
-Datum		_ltxtq_exec(PG_FUNCTION_ARGS);
-Datum		_ltxtq_rexec(PG_FUNCTION_ARGS);
-Datum		_ltree_isparent(PG_FUNCTION_ARGS);
-Datum		_ltree_risparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_isparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_risparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltq_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltq_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		lt_q_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		lt_q_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltxtq_exec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltxtq_rexec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltq_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltq_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_lt_q_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_lt_q_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltxtq_exec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltxtq_rexec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltree_isparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		_ltree_risparent(PG_FUNCTION_ARGS);
 
 /* Concatenation functions */
-Datum		ltree_addltree(PG_FUNCTION_ARGS);
-Datum		ltree_addtext(PG_FUNCTION_ARGS);
-Datum		ltree_textadd(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_addltree(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_addtext(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_textadd(PG_FUNCTION_ARGS);
 
 /* Util function */
-Datum		ltree_in(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum		ltree_in(PG_FUNCTION_ARGS);
 
 bool		ltree_execute(ITEM *curitem, void *checkval,
 						  bool calcnot, bool (*chkcond) (void *checkval, ITEM *val));
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 05c54b27de..aa153faaaf 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -259,6 +259,8 @@ SUN_STUDIO_CC = @SUN_STUDIO_CC@
 CXX = @CXX@
 CFLAGS = @CFLAGS@
 CFLAGS_SL = @CFLAGS_SL@
+CFLAGS_SL_MOD = @CFLAGS_SL_MOD@
+CXXFLAGS_SL_MOD = @CXXFLAGS_SL_MOD@
 CFLAGS_UNROLL_LOOPS = @CFLAGS_UNROLL_LOOPS@
 CFLAGS_VECTORIZE = @CFLAGS_VECTORIZE@
 CFLAGS_SSE42 = @CFLAGS_SSE42@
diff --git a/src/Makefile.shlib b/src/Makefile.shlib
index 551023c6fb..9119e9bb5d 100644
--- a/src/Makefile.shlib
+++ b/src/Makefile.shlib
@@ -253,6 +253,19 @@ ifeq ($(PORTNAME), win32)
 endif
 
 
+# If the shared library doesn't have an export file, mark all symbols not
+# explicitly exported using PGDLLEXPORT as hidden. We can't pass these flags
+# when building a library with explicit exports, as the symbols would be
+# hidden before the linker script / exported symbol list takes effect.
+#
+# XXX: This probably isn't the best location, but not clear where else
+# instead?
+ifeq ($(SHLIB_EXPORTS),)
+  LDFLAGS += $(CFLAGS_SL_MOD)
+  override CFLAGS += $(CFLAGS_SL_MOD)
+  override CXXFLAGS += $(CXXFLAGS_SL_MOD)
+endif
+
 
 ##
 ## BUILD
diff --git a/src/include/c.h b/src/include/c.h
index 4f16e589b3..b713123b61 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -1336,14 +1336,19 @@ extern unsigned long long strtoull(const char *str, char **endptr, int base);
 
 /*
  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
- * loadable modules and need to be callable by the core backend.  (Usually,
- * this is not necessary because our build process automatically exports
- * such symbols, but sometimes manual marking is required.)
- * No special marking is required on most ports.
+ * loadable modules and need to be callable by the core backend or other
+ * loadable modules.
+ * If the compiler knows __attribute__((visibility("*"))), we use that,
+ * unless we already have a platform-specific definition.  Otherwise,
+ * no special marking is required.
  */
 #ifndef PGDLLEXPORT
+#ifdef HAVE_VISIBILITY_ATTRIBUTE
+#define PGDLLEXPORT __attribute__((visibility("default")))
+#else
 #define PGDLLEXPORT
 #endif
+#endif
 
 /*
  * The following is used as the arg list for signal handlers.  Any ports
diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 6560e462d6..3c813559f3 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -413,7 +413,7 @@ typedef const Pg_finfo_record *(*PGFInfoFunction) (void);
  *	info function, since authors shouldn't need to be explicitly aware of it.
  */
 #define PG_FUNCTION_INFO_V1(funcname) \
-extern Datum funcname(PG_FUNCTION_ARGS); \
+extern PGDLLEXPORT Datum funcname(PG_FUNCTION_ARGS); \
 extern PGDLLEXPORT const Pg_finfo_record * CppConcat(pg_finfo_,funcname)(void); \
 const Pg_finfo_record * \
 CppConcat(pg_finfo_,funcname) (void) \
@@ -424,6 +424,16 @@ CppConcat(pg_finfo_,funcname) (void) \
 extern int no_such_variable
 
 
+/*
+ * Declare _PG_init/_PG_fini centrally. Historically each shared library had
+ * its own declaration, but now that we want to mark the symbols PGDLLEXPORT,
+ * the central declaration helps find extensions with local declarations
+ * missing PGDLLEXPORT.
+ */
+extern PGDLLEXPORT void _PG_init(void);
+extern PGDLLEXPORT void _PG_fini(void);
+
+
 /*-------------------------------------------------------------------------
  *		Support for verifying backend compatibility of loaded modules
  *
diff --git a/src/include/jit/jit.h b/src/include/jit/jit.h
index 707176d9ed..5870ec6d7b 100644
--- a/src/include/jit/jit.h
+++ b/src/include/jit/jit.h
@@ -63,7 +63,7 @@ typedef struct JitContext
 
 typedef struct JitProviderCallbacks JitProviderCallbacks;
 
-extern void _PG_jit_provider_init(JitProviderCallbacks *cb);
+extern PGDLLEXPORT void _PG_jit_provider_init(JitProviderCallbacks *cb);
 typedef void (*JitProviderInit) (JitProviderCallbacks *cb);
 typedef void (*JitProviderResetAfterErrorCB) (void);
 typedef void (*JitProviderReleaseContextCB) (JitContext *context);
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 9d9bd6b9ef..28b22bd8d6 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -701,6 +701,9 @@
 /* Define to 1 if you have the <uuid/uuid.h> header file. */
 #undef HAVE_UUID_UUID_H
 
+/* Define to 1 if your compiler knows the visibility("hidden") attribute. */
+#undef HAVE_VISIBILITY_ATTRIBUTE
+
 /* Define to 1 if you have the `wcstombs_l' function. */
 #undef HAVE_WCSTOMBS_L
 
diff --git a/src/include/replication/output_plugin.h b/src/include/replication/output_plugin.h
index 41157fda7c..490aa50825 100644
--- a/src/include/replication/output_plugin.h
+++ b/src/include/replication/output_plugin.h
@@ -35,6 +35,8 @@ typedef struct OutputPluginOptions
  */
 typedef void (*LogicalOutputPluginInit) (struct OutputPluginCallbacks *cb);
 
+extern PGDLLEXPORT void _PG_output_plugin_init(struct OutputPluginCallbacks *cb);
+
 /*
  * Callback that gets called in a user-defined plugin. ctx->private_data can
  * be set to some private data.
diff --git a/src/pl/plpython/plpy_elog.h b/src/pl/plpython/plpy_elog.h
index e02ef4ffe9..aeade82ce1 100644
--- a/src/pl/plpython/plpy_elog.h
+++ b/src/pl/plpython/plpy_elog.h
@@ -34,13 +34,13 @@ extern PyObject *PLy_exc_spi_error;
 	} while(0)
 #endif							/* HAVE__BUILTIN_CONSTANT_P */
 
-extern void PLy_elog_impl(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
+extern PGDLLEXPORT void PLy_elog_impl(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
 
-extern void PLy_exception_set(PyObject *exc, const char *fmt,...) pg_attribute_printf(2, 3);
+extern PGDLLEXPORT void PLy_exception_set(PyObject *exc, const char *fmt,...) pg_attribute_printf(2, 3);
 
-extern void PLy_exception_set_plural(PyObject *exc, const char *fmt_singular, const char *fmt_plural,
+extern PGDLLEXPORT void PLy_exception_set_plural(PyObject *exc, const char *fmt_singular, const char *fmt_plural,
 									 unsigned long n,...) pg_attribute_printf(2, 5) pg_attribute_printf(3, 5);
 
-extern void PLy_exception_set_with_details(PyObject *excclass, ErrorData *edata);
+extern PGDLLEXPORT void PLy_exception_set_with_details(PyObject *excclass, ErrorData *edata);
 
 #endif							/* PLPY_ELOG_H */
diff --git a/src/pl/plpython/plpy_typeio.h b/src/pl/plpython/plpy_typeio.h
index d11e6ae1b8..87e3b2c464 100644
--- a/src/pl/plpython/plpy_typeio.h
+++ b/src/pl/plpython/plpy_typeio.h
@@ -147,29 +147,29 @@ struct PLyObToDatum
 };
 
 
-extern PyObject *PLy_input_convert(PLyDatumToOb *arg, Datum val);
-extern Datum PLy_output_convert(PLyObToDatum *arg, PyObject *val,
+extern PGDLLEXPORT PyObject *PLy_input_convert(PLyDatumToOb *arg, Datum val);
+extern PGDLLEXPORT Datum PLy_output_convert(PLyObToDatum *arg, PyObject *val,
 								bool *isnull);
 
-extern PyObject *PLy_input_from_tuple(PLyDatumToOb *arg, HeapTuple tuple,
+extern PGDLLEXPORT PyObject *PLy_input_from_tuple(PLyDatumToOb *arg, HeapTuple tuple,
 									  TupleDesc desc, bool include_generated);
 
-extern void PLy_input_setup_func(PLyDatumToOb *arg, MemoryContext arg_mcxt,
+extern PGDLLEXPORT void PLy_input_setup_func(PLyDatumToOb *arg, MemoryContext arg_mcxt,
 								 Oid typeOid, int32 typmod,
 								 struct PLyProcedure *proc);
-extern void PLy_output_setup_func(PLyObToDatum *arg, MemoryContext arg_mcxt,
+extern PGDLLEXPORT void PLy_output_setup_func(PLyObToDatum *arg, MemoryContext arg_mcxt,
 								  Oid typeOid, int32 typmod,
 								  struct PLyProcedure *proc);
 
-extern void PLy_input_setup_tuple(PLyDatumToOb *arg, TupleDesc desc,
+extern PGDLLEXPORT void PLy_input_setup_tuple(PLyDatumToOb *arg, TupleDesc desc,
 								  struct PLyProcedure *proc);
-extern void PLy_output_setup_tuple(PLyObToDatum *arg, TupleDesc desc,
+extern PGDLLEXPORT void PLy_output_setup_tuple(PLyObToDatum *arg, TupleDesc desc,
 								   struct PLyProcedure *proc);
 
-extern void PLy_output_setup_record(PLyObToDatum *arg, TupleDesc desc,
+extern PGDLLEXPORT void PLy_output_setup_record(PLyObToDatum *arg, TupleDesc desc,
 									struct PLyProcedure *proc);
 
 /* conversion from Python objects to C strings --- exported for transforms */
-extern char *PLyObject_AsString(PyObject *plrv);
+extern PGDLLEXPORT char *PLyObject_AsString(PyObject *plrv);
 
 #endif							/* PLPY_TYPEIO_H */
diff --git a/src/pl/plpython/plpy_util.h b/src/pl/plpython/plpy_util.h
index c9ba7edc0e..6927601e0b 100644
--- a/src/pl/plpython/plpy_util.h
+++ b/src/pl/plpython/plpy_util.h
@@ -8,12 +8,12 @@
 
 #include "plpython.h"
 
-extern PyObject *PLyUnicode_Bytes(PyObject *unicode);
-extern char *PLyUnicode_AsString(PyObject *unicode);
+extern PGDLLEXPORT PyObject *PLyUnicode_Bytes(PyObject *unicode);
+extern PGDLLEXPORT char *PLyUnicode_AsString(PyObject *unicode);
 
 #if PY_MAJOR_VERSION >= 3
-extern PyObject *PLyUnicode_FromString(const char *s);
-extern PyObject *PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size);
+extern PGDLLEXPORT PyObject *PLyUnicode_FromString(const char *s);
+extern PGDLLEXPORT PyObject *PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size);
 #endif
 
 #endif							/* PLPY_UTIL_H */
diff --git a/src/test/modules/test_shm_mq/test_shm_mq.h b/src/test/modules/test_shm_mq/test_shm_mq.h
index 0310caf50b..8f97be78d3 100644
--- a/src/test/modules/test_shm_mq/test_shm_mq.h
+++ b/src/test/modules/test_shm_mq/test_shm_mq.h
@@ -40,6 +40,6 @@ extern void test_shm_mq_setup(int64 queue_size, int32 nworkers,
 							  shm_mq_handle **input);
 
 /* Main entrypoint for a worker. */
-extern void test_shm_mq_main(Datum) pg_attribute_noreturn();
+extern PGDLLEXPORT void test_shm_mq_main(Datum) pg_attribute_noreturn();
 
 #endif
diff --git a/src/test/modules/worker_spi/worker_spi.c b/src/test/modules/worker_spi/worker_spi.c
index 05ced63780..a1f4dbaf3f 100644
--- a/src/test/modules/worker_spi/worker_spi.c
+++ b/src/test/modules/worker_spi/worker_spi.c
@@ -47,7 +47,7 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(worker_spi_launch);
 
 void		_PG_init(void);
-void		worker_spi_main(Datum) pg_attribute_noreturn();
+PGDLLEXPORT void worker_spi_main(Datum) pg_attribute_noreturn();
 
 /* GUC variables */
 static int	worker_spi_naptime = 10;
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index e47c2d648c..e076fa2a92 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -429,6 +429,7 @@ sub GenerateFiles
 		HAVE_WINLDAP_H                           => undef,
 		HAVE_WCSTOMBS_L                          => 1,
 		HAVE_WCTYPE_H                            => 1,
+		HAVE_VISIBILITY_ATTRIBUTE                => undef,
 		HAVE_WRITEV                              => undef,
 		HAVE_X509_GET_SIGNATURE_NID              => 1,
 		HAVE_X86_64_POPCNTQ                      => undef,

From b442f1a047c2648c609675dd8d292a3d6a50b45f Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 16 Jul 2022 12:48:16 -0700
Subject: [PATCH v3 1/4] Add central declarations for dlsym()ed symbols

This is in preparation for defaulting to -fvisibility=hidden in extensions,
instead of relying on all symbols in extensions to be exported. For that
exported symbols need to be tagged with PGDLLEXPORT. Most extensions only need
to do so for _PG_init() and functions defined with PG_FUNCTION_INFO_V1. Adding
central declarations with PGDLLEXPORT avoids breaking extensions declaring
_PG_init(), as long as they include fmgr.h before the declaration.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
---
 src/include/fmgr.h                      | 11 +++++++++++
 src/include/jit/jit.h                   |  2 +-
 src/include/postmaster/pgarch.h         |  2 ++
 src/include/replication/output_plugin.h |  2 ++
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 5314b737052..7f0c37470a6 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -424,6 +424,17 @@ CppConcat(pg_finfo_,funcname) (void) \
 extern int no_such_variable
 
 
+/*
+ * Declare _PG_init/_PG_fini centrally. Historically each shared library had
+ * its own declaration, but now that we want to mark the symbols PGDLLEXPORT,
+ * the central declaration avoids each extension having to add it. The
+ * existing declaration in extensions continue to work as long as fmgr.h is
+ * included before, otherwise compilation targetting windows fails.
+ */
+extern PGDLLEXPORT void _PG_init(void);
+extern PGDLLEXPORT void _PG_fini(void);
+
+
 /*-------------------------------------------------------------------------
  *		Support for verifying backend compatibility of loaded modules
  *
diff --git a/src/include/jit/jit.h b/src/include/jit/jit.h
index d1940332094..600ddfc7539 100644
--- a/src/include/jit/jit.h
+++ b/src/include/jit/jit.h
@@ -63,7 +63,7 @@ typedef struct JitContext
 
 typedef struct JitProviderCallbacks JitProviderCallbacks;
 
-extern void _PG_jit_provider_init(JitProviderCallbacks *cb);
+extern PGDLLEXPORT void _PG_jit_provider_init(JitProviderCallbacks *cb);
 typedef void (*JitProviderInit) (JitProviderCallbacks *cb);
 typedef void (*JitProviderResetAfterErrorCB) (void);
 typedef void (*JitProviderReleaseContextCB) (JitContext *context);
diff --git a/src/include/postmaster/pgarch.h b/src/include/postmaster/pgarch.h
index f366a159a8e..2546e2ae883 100644
--- a/src/include/postmaster/pgarch.h
+++ b/src/include/postmaster/pgarch.h
@@ -63,6 +63,8 @@ typedef struct ArchiveModuleCallbacks
  */
 typedef void (*ArchiveModuleInit) (ArchiveModuleCallbacks *cb);
 
+extern PGDLLEXPORT void _PG_archive_module_init(ArchiveModuleCallbacks *cb);
+
 /*
  * Since the logic for archiving via a shell command is in the core server
  * and does not need to be loaded via a shared library, it has a special
diff --git a/src/include/replication/output_plugin.h b/src/include/replication/output_plugin.h
index 539dc8e6974..b7d28d7045c 100644
--- a/src/include/replication/output_plugin.h
+++ b/src/include/replication/output_plugin.h
@@ -35,6 +35,8 @@ typedef struct OutputPluginOptions
  */
 typedef void (*LogicalOutputPluginInit) (struct OutputPluginCallbacks *cb);
 
+extern PGDLLEXPORT void _PG_output_plugin_init(struct OutputPluginCallbacks *cb);
+
 /*
  * Callback that gets called in a user-defined plugin. ctx->private_data can
  * be set to some private data.
-- 
2.37.0.3.g30cc8d0f14

From 56267aef457920f69289bb701830d920f340f9a8 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 16 Jul 2022 12:55:22 -0700
Subject: [PATCH v3 2/4] Remove now superfluous declarations of other dlsym()ed
 symbols.

After the prior commit they're declared centrally.

Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
---
 src/backend/replication/libpqwalreceiver/libpqwalreceiver.c  | 2 --
 src/backend/replication/pgoutput/pgoutput.c                  | 2 --
 src/pl/plperl/plperl.c                                       | 1 -
 src/pl/plpgsql/src/plpgsql.h                                 | 5 -----
 src/pl/plpython/plpy_main.c                                  | 2 --
 src/pl/tcl/pltcl.c                                           | 1 -
 contrib/auth_delay/auth_delay.c                              | 2 --
 contrib/auto_explain/auto_explain.c                          | 2 --
 contrib/basebackup_to_shell/basebackup_to_shell.c            | 2 --
 contrib/basic_archive/basic_archive.c                        | 3 ---
 contrib/bloom/bloom.h                                        | 1 -
 contrib/hstore_plperl/hstore_plperl.c                        | 2 --
 contrib/hstore_plpython/hstore_plpython.c                    | 2 --
 contrib/isn/isn.c                                            | 2 --
 contrib/jsonb_plpython/jsonb_plpython.c                      | 2 --
 contrib/ltree_plpython/ltree_plpython.c                      | 2 --
 contrib/passwordcheck/passwordcheck.c                        | 2 --
 contrib/pg_prewarm/autoprewarm.c                             | 1 -
 contrib/pg_stat_statements/pg_stat_statements.c              | 2 --
 contrib/pg_trgm/trgm_op.c                                    | 2 --
 contrib/postgres_fdw/option.c                                | 2 --
 contrib/sepgsql/hooks.c                                      | 1 -
 contrib/test_decoding/test_decoding.c                        | 4 ----
 src/test/modules/delay_execution/delay_execution.c           | 3 ---
 src/test/modules/dummy_index_am/dummy_index_am.c             | 2 --
 src/test/modules/dummy_seclabel/dummy_seclabel.c             | 3 ---
 .../modules/ssl_passphrase_callback/ssl_passphrase_func.c    | 2 --
 src/test/modules/test_oat_hooks/test_oat_hooks.c             | 2 --
 src/test/modules/test_rls_hooks/test_rls_hooks.c             | 2 --
 src/test/modules/test_shm_mq/test.c                          | 2 --
 src/test/modules/worker_spi/worker_spi.c                     | 1 -
 31 files changed, 64 deletions(-)

diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 0d89db4e6a6..0b775b1e985 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -36,8 +36,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 struct WalReceiverConn
 {
 	/* Current connection to the primary, if any */
diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
index 2cbca4a0870..ba8a24d0999 100644
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -35,8 +35,6 @@
 
 PG_MODULE_MAGIC;
 
-extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
-
 static void pgoutput_startup(LogicalDecodingContext *ctx,
 							 OutputPluginOptions *opt, bool is_init);
 static void pgoutput_shutdown(LogicalDecodingContext *ctx);
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index edb93ec1c4c..af354a68ccd 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -245,7 +245,6 @@ static plperl_call_data *current_call_data = NULL;
 /**********************************************************************
  * Forward declarations
  **********************************************************************/
-void		_PG_init(void);
 
 static PerlInterpreter *plperl_init_interp(void);
 static void plperl_destroy_interp(PerlInterpreter **);
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 4e6ee1c6198..19141602729 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -1264,11 +1264,6 @@ extern void plpgsql_adddatum(PLpgSQL_datum *newdatum);
 extern int	plpgsql_add_initdatums(int **varnos);
 extern void plpgsql_HashTableInit(void);
 
-/*
- * Functions in pl_handler.c
- */
-extern void _PG_init(void);
-
 /*
  * Functions in pl_exec.c
  */
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 0bce1064951..a4d66f3057f 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -28,8 +28,6 @@
  * exported functions
  */
 
-extern void _PG_init(void);
-
 PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(plpython3_validator);
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 0dd6d8ab2c2..eaa98d42c2e 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -261,7 +261,6 @@ static const TclExceptionNameMap exception_name_map[] = {
 /**********************************************************************
  * Forward declarations
  **********************************************************************/
-void		_PG_init(void);
 
 static void pltcl_init_interp(pltcl_interp_desc *interp_desc,
 							  Oid prolang, bool pltrusted);
diff --git a/contrib/auth_delay/auth_delay.c b/contrib/auth_delay/auth_delay.c
index 6b94d653ea4..c3d78e5020f 100644
--- a/contrib/auth_delay/auth_delay.c
+++ b/contrib/auth_delay/auth_delay.c
@@ -20,8 +20,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 /* GUC Variables */
 static int	auth_delay_milliseconds;
 
diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
index 1ba7536879d..269a0fa86c5 100644
--- a/contrib/auto_explain/auto_explain.c
+++ b/contrib/auto_explain/auto_explain.c
@@ -78,8 +78,6 @@ static ExecutorRun_hook_type prev_ExecutorRun = NULL;
 static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
 static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
 
-void		_PG_init(void);
-
 static void explain_ExecutorStart(QueryDesc *queryDesc, int eflags);
 static void explain_ExecutorRun(QueryDesc *queryDesc,
 								ScanDirection direction,
diff --git a/contrib/basebackup_to_shell/basebackup_to_shell.c b/contrib/basebackup_to_shell/basebackup_to_shell.c
index bc754b177af..34188f2d9d3 100644
--- a/contrib/basebackup_to_shell/basebackup_to_shell.c
+++ b/contrib/basebackup_to_shell/basebackup_to_shell.c
@@ -37,8 +37,6 @@ typedef struct bbsink_shell
 	FILE	   *pipe;
 } bbsink_shell;
 
-void		_PG_init(void);
-
 static void *shell_check_detail(char *target, char *target_detail);
 static bbsink *shell_get_sink(bbsink *next_sink, void *detail_arg);
 
diff --git a/contrib/basic_archive/basic_archive.c b/contrib/basic_archive/basic_archive.c
index 6b550fc55f7..bba767c8f36 100644
--- a/contrib/basic_archive/basic_archive.c
+++ b/contrib/basic_archive/basic_archive.c
@@ -40,9 +40,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-void		_PG_archive_module_init(ArchiveModuleCallbacks *cb);
-
 static char *archive_directory = NULL;
 static MemoryContext basic_archive_context;
 
diff --git a/contrib/bloom/bloom.h b/contrib/bloom/bloom.h
index 9966f3f46e1..6d58e22813d 100644
--- a/contrib/bloom/bloom.h
+++ b/contrib/bloom/bloom.h
@@ -175,7 +175,6 @@ typedef struct BloomScanOpaqueData
 typedef BloomScanOpaqueData *BloomScanOpaque;
 
 /* blutils.c */
-extern void _PG_init(void);
 extern void initBloomState(BloomState *state, Relation index);
 extern void BloomFillMetapage(Relation index, Page metaPage);
 extern void BloomInitMetapage(Relation index);
diff --git a/contrib/hstore_plperl/hstore_plperl.c b/contrib/hstore_plperl/hstore_plperl.c
index 417b721cff9..c72785d99ec 100644
--- a/contrib/hstore_plperl/hstore_plperl.c
+++ b/contrib/hstore_plperl/hstore_plperl.c
@@ -7,8 +7,6 @@
 
 PG_MODULE_MAGIC;
 
-extern void _PG_init(void);
-
 /* Linkage to functions in hstore module */
 typedef HStore *(*hstoreUpgrade_t) (Datum orig);
 static hstoreUpgrade_t hstoreUpgrade_p;
diff --git a/contrib/hstore_plpython/hstore_plpython.c b/contrib/hstore_plpython/hstore_plpython.c
index 0be65075916..961579a5ea0 100644
--- a/contrib/hstore_plpython/hstore_plpython.c
+++ b/contrib/hstore_plpython/hstore_plpython.c
@@ -7,8 +7,6 @@
 
 PG_MODULE_MAGIC;
 
-extern void _PG_init(void);
-
 /* Linkage to functions in plpython module */
 typedef char *(*PLyObject_AsString_t) (PyObject *plrv);
 static PLyObject_AsString_t PLyObject_AsString_p;
diff --git a/contrib/isn/isn.c b/contrib/isn/isn.c
index 7493a2c60fa..a53d99722ad 100644
--- a/contrib/isn/isn.c
+++ b/contrib/isn/isn.c
@@ -924,8 +924,6 @@ eantoobig:
  * Exported routines.
  *---------------------------------------------------------*/
 
-void		_PG_init(void);
-
 void
 _PG_init(void)
 {
diff --git a/contrib/jsonb_plpython/jsonb_plpython.c b/contrib/jsonb_plpython/jsonb_plpython.c
index 03bbfa87d9a..a625727c5e8 100644
--- a/contrib/jsonb_plpython/jsonb_plpython.c
+++ b/contrib/jsonb_plpython/jsonb_plpython.c
@@ -9,8 +9,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 /* for PLyObject_AsString in plpy_typeio.c */
 typedef char *(*PLyObject_AsString_t) (PyObject *plrv);
 static PLyObject_AsString_t PLyObject_AsString_p;
diff --git a/contrib/ltree_plpython/ltree_plpython.c b/contrib/ltree_plpython/ltree_plpython.c
index 7431a1150a9..ac159ea3141 100644
--- a/contrib/ltree_plpython/ltree_plpython.c
+++ b/contrib/ltree_plpython/ltree_plpython.c
@@ -6,8 +6,6 @@
 
 PG_MODULE_MAGIC;
 
-extern void _PG_init(void);
-
 /* Linkage to functions in plpython module */
 typedef PyObject *(*PLyUnicode_FromStringAndSize_t) (const char *s, Py_ssize_t size);
 static PLyUnicode_FromStringAndSize_t PLyUnicode_FromStringAndSize_p;
diff --git a/contrib/passwordcheck/passwordcheck.c b/contrib/passwordcheck/passwordcheck.c
index 9d8c58ded09..c24b1cbe43e 100644
--- a/contrib/passwordcheck/passwordcheck.c
+++ b/contrib/passwordcheck/passwordcheck.c
@@ -32,8 +32,6 @@ static check_password_hook_type prev_check_password_hook = NULL;
 /* passwords shorter than this will be rejected */
 #define MIN_PWD_LENGTH 8
 
-extern void _PG_init(void);
-
 /*
  * check_password
  *
diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c
index 13eee4a1379..b2d60260934 100644
--- a/contrib/pg_prewarm/autoprewarm.c
+++ b/contrib/pg_prewarm/autoprewarm.c
@@ -82,7 +82,6 @@ typedef struct AutoPrewarmSharedState
 	int			prewarmed_blocks;
 } AutoPrewarmSharedState;
 
-void		_PG_init(void);
 void		autoprewarm_main(Datum main_arg);
 void		autoprewarm_database_main(Datum main_arg);
 
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index b4d4231dc61..049da9fe6df 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -305,8 +305,6 @@ static bool pgss_save;			/* whether to save stats across shutdown */
 
 /*---- Function declarations ----*/
 
-void		_PG_init(void);
-
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_7);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
diff --git a/contrib/pg_trgm/trgm_op.c b/contrib/pg_trgm/trgm_op.c
index cbcc481a172..49b3609de93 100644
--- a/contrib/pg_trgm/trgm_op.c
+++ b/contrib/pg_trgm/trgm_op.c
@@ -20,8 +20,6 @@ double		similarity_threshold = 0.3f;
 double		word_similarity_threshold = 0.6f;
 double		strict_word_similarity_threshold = 0.5f;
 
-void		_PG_init(void);
-
 PG_FUNCTION_INFO_V1(set_limit);
 PG_FUNCTION_INFO_V1(show_limit);
 PG_FUNCTION_INFO_V1(show_trgm);
diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c
index 572591a558d..cd2ef234d66 100644
--- a/contrib/postgres_fdw/option.c
+++ b/contrib/postgres_fdw/option.c
@@ -51,8 +51,6 @@ static PQconninfoOption *libpq_options;
  */
 char	   *pgfdw_application_name = NULL;
 
-void		_PG_init(void);
-
 /*
  * Helper functions
  */
diff --git a/contrib/sepgsql/hooks.c b/contrib/sepgsql/hooks.c
index 97e61b8043f..87fdd972c27 100644
--- a/contrib/sepgsql/hooks.c
+++ b/contrib/sepgsql/hooks.c
@@ -30,7 +30,6 @@ PG_MODULE_MAGIC;
 /*
  * Declarations
  */
-void		_PG_init(void);
 
 /*
  * Saved hook entries (if stacked)
diff --git a/contrib/test_decoding/test_decoding.c b/contrib/test_decoding/test_decoding.c
index 3736da6784b..3f90ffa32de 100644
--- a/contrib/test_decoding/test_decoding.c
+++ b/contrib/test_decoding/test_decoding.c
@@ -24,10 +24,6 @@
 
 PG_MODULE_MAGIC;
 
-/* These must be available to dlsym() */
-extern void _PG_init(void);
-extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
-
 typedef struct
 {
 	MemoryContext context;
diff --git a/src/test/modules/delay_execution/delay_execution.c b/src/test/modules/delay_execution/delay_execution.c
index 407ebc0edaf..756c161872c 100644
--- a/src/test/modules/delay_execution/delay_execution.c
+++ b/src/test/modules/delay_execution/delay_execution.c
@@ -36,9 +36,6 @@ static int	post_planning_lock_id = 0;
 /* Save previous planner hook user to be a good citizen */
 static planner_hook_type prev_planner_hook = NULL;
 
-/* Module load function */
-void		_PG_init(void);
-
 
 /* planner_hook function to provide the desired delay */
 static PlannedStmt *
diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c
index a0894ff9860..67c30394c80 100644
--- a/src/test/modules/dummy_index_am/dummy_index_am.c
+++ b/src/test/modules/dummy_index_am/dummy_index_am.c
@@ -23,8 +23,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 /* parse table for fillRelOptions */
 relopt_parse_elt di_relopt_tab[6];
 
diff --git a/src/test/modules/dummy_seclabel/dummy_seclabel.c b/src/test/modules/dummy_seclabel/dummy_seclabel.c
index 67658c1e122..8b03dcd7545 100644
--- a/src/test/modules/dummy_seclabel/dummy_seclabel.c
+++ b/src/test/modules/dummy_seclabel/dummy_seclabel.c
@@ -19,9 +19,6 @@
 
 PG_MODULE_MAGIC;
 
-/* Entrypoint of the module */
-void		_PG_init(void);
-
 PG_FUNCTION_INFO_V1(dummy_seclabel_dummy);
 
 static void
diff --git a/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c b/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c
index e9f2329a5aa..948706af852 100644
--- a/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c
+++ b/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c
@@ -20,8 +20,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 static char *ssl_passphrase = NULL;
 
 /* callback function */
diff --git a/src/test/modules/test_oat_hooks/test_oat_hooks.c b/src/test/modules/test_oat_hooks/test_oat_hooks.c
index 900d597f5dd..8aa59bf18ad 100644
--- a/src/test/modules/test_oat_hooks/test_oat_hooks.c
+++ b/src/test/modules/test_oat_hooks/test_oat_hooks.c
@@ -69,8 +69,6 @@ static char *accesstype_to_string(ObjectAccessType access, int subId);
 static char *accesstype_arg_to_string(ObjectAccessType access, void *arg);
 
 
-void		_PG_init(void);
-
 /*
  * Module load callback
  */
diff --git a/src/test/modules/test_rls_hooks/test_rls_hooks.c b/src/test/modules/test_rls_hooks/test_rls_hooks.c
index fd2864130eb..496846d9f49 100644
--- a/src/test/modules/test_rls_hooks/test_rls_hooks.c
+++ b/src/test/modules/test_rls_hooks/test_rls_hooks.c
@@ -29,8 +29,6 @@
 
 PG_MODULE_MAGIC;
 
-void		_PG_init(void);
-
 /* Install hooks */
 void
 _PG_init(void)
diff --git a/src/test/modules/test_shm_mq/test.c b/src/test/modules/test_shm_mq/test.c
index 5a788692d95..1d1c184d8ce 100644
--- a/src/test/modules/test_shm_mq/test.c
+++ b/src/test/modules/test_shm_mq/test.c
@@ -24,8 +24,6 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(test_shm_mq);
 PG_FUNCTION_INFO_V1(test_shm_mq_pipelined);
 
-void		_PG_init(void);
-
 static void verify_message(Size origlen, char *origdata, Size newlen,
 						   char *newdata);
 
diff --git a/src/test/modules/worker_spi/worker_spi.c b/src/test/modules/worker_spi/worker_spi.c
index 5b541ec47f1..b37ef8beb60 100644
--- a/src/test/modules/worker_spi/worker_spi.c
+++ b/src/test/modules/worker_spi/worker_spi.c
@@ -46,7 +46,6 @@ PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(worker_spi_launch);
 
-void		_PG_init(void);
 void		worker_spi_main(Datum) pg_attribute_noreturn();
 
 /* GUC variables */
-- 
2.37.0.3.g30cc8d0f14

From 56e68c99814550f702a8c9353930404027631219 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 16 Jul 2022 13:07:02 -0700
Subject: [PATCH v3 3/4] Mark all symbols exported from extension libraries
 PGDLLEXPORT.

This is in preparation for defaulting to -fvisibility=hidden in extensions,
instead of relying on all symbols in extensions to be exported.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
---
 src/include/fmgr.h                         |  2 +-
 src/pl/plpython/plpy_elog.h                | 10 +++---
 src/pl/plpython/plpy_typeio.h              | 36 +++++++++----------
 src/pl/plpython/plpy_util.h                |  8 ++---
 contrib/hstore/hstore.h                    | 16 ++++-----
 contrib/ltree/ltree.h                      | 40 +++++++++++-----------
 src/test/modules/test_shm_mq/test_shm_mq.h |  2 +-
 src/test/modules/worker_spi/worker_spi.c   |  2 +-
 8 files changed, 58 insertions(+), 58 deletions(-)

diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 7f0c37470a6..aa09360bda7 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -413,7 +413,7 @@ typedef const Pg_finfo_record *(*PGFInfoFunction) (void);
  *	info function, since authors shouldn't need to be explicitly aware of it.
  */
 #define PG_FUNCTION_INFO_V1(funcname) \
-extern Datum funcname(PG_FUNCTION_ARGS); \
+extern PGDLLEXPORT Datum funcname(PG_FUNCTION_ARGS); \
 extern PGDLLEXPORT const Pg_finfo_record * CppConcat(pg_finfo_,funcname)(void); \
 const Pg_finfo_record * \
 CppConcat(pg_finfo_,funcname) (void) \
diff --git a/src/pl/plpython/plpy_elog.h b/src/pl/plpython/plpy_elog.h
index e02ef4ffe9f..dc65f2f6ee2 100644
--- a/src/pl/plpython/plpy_elog.h
+++ b/src/pl/plpython/plpy_elog.h
@@ -34,13 +34,13 @@ extern PyObject *PLy_exc_spi_error;
 	} while(0)
 #endif							/* HAVE__BUILTIN_CONSTANT_P */
 
-extern void PLy_elog_impl(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
+extern PGDLLEXPORT void PLy_elog_impl(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
 
-extern void PLy_exception_set(PyObject *exc, const char *fmt,...) pg_attribute_printf(2, 3);
+extern PGDLLEXPORT void PLy_exception_set(PyObject *exc, const char *fmt,...) pg_attribute_printf(2, 3);
 
-extern void PLy_exception_set_plural(PyObject *exc, const char *fmt_singular, const char *fmt_plural,
-									 unsigned long n,...) pg_attribute_printf(2, 5) pg_attribute_printf(3, 5);
+extern PGDLLEXPORT void PLy_exception_set_plural(PyObject *exc, const char *fmt_singular, const char *fmt_plural,
+												 unsigned long n,...) pg_attribute_printf(2, 5) pg_attribute_printf(3, 5);
 
-extern void PLy_exception_set_with_details(PyObject *excclass, ErrorData *edata);
+extern PGDLLEXPORT void PLy_exception_set_with_details(PyObject *excclass, ErrorData *edata);
 
 #endif							/* PLPY_ELOG_H */
diff --git a/src/pl/plpython/plpy_typeio.h b/src/pl/plpython/plpy_typeio.h
index d11e6ae1b89..5417f0945d2 100644
--- a/src/pl/plpython/plpy_typeio.h
+++ b/src/pl/plpython/plpy_typeio.h
@@ -147,29 +147,29 @@ struct PLyObToDatum
 };
 
 
-extern PyObject *PLy_input_convert(PLyDatumToOb *arg, Datum val);
-extern Datum PLy_output_convert(PLyObToDatum *arg, PyObject *val,
-								bool *isnull);
+extern PGDLLEXPORT PyObject *PLy_input_convert(PLyDatumToOb *arg, Datum val);
+extern PGDLLEXPORT Datum PLy_output_convert(PLyObToDatum *arg, PyObject *val,
+											bool *isnull);
 
-extern PyObject *PLy_input_from_tuple(PLyDatumToOb *arg, HeapTuple tuple,
-									  TupleDesc desc, bool include_generated);
+extern PGDLLEXPORT PyObject *PLy_input_from_tuple(PLyDatumToOb *arg, HeapTuple tuple,
+												  TupleDesc desc, bool include_generated);
 
-extern void PLy_input_setup_func(PLyDatumToOb *arg, MemoryContext arg_mcxt,
-								 Oid typeOid, int32 typmod,
-								 struct PLyProcedure *proc);
-extern void PLy_output_setup_func(PLyObToDatum *arg, MemoryContext arg_mcxt,
-								  Oid typeOid, int32 typmod,
-								  struct PLyProcedure *proc);
+extern PGDLLEXPORT void PLy_input_setup_func(PLyDatumToOb *arg, MemoryContext arg_mcxt,
+											 Oid typeOid, int32 typmod,
+											 struct PLyProcedure *proc);
+extern PGDLLEXPORT void PLy_output_setup_func(PLyObToDatum *arg, MemoryContext arg_mcxt,
+											  Oid typeOid, int32 typmod,
+											  struct PLyProcedure *proc);
 
-extern void PLy_input_setup_tuple(PLyDatumToOb *arg, TupleDesc desc,
-								  struct PLyProcedure *proc);
-extern void PLy_output_setup_tuple(PLyObToDatum *arg, TupleDesc desc,
-								   struct PLyProcedure *proc);
+extern PGDLLEXPORT void PLy_input_setup_tuple(PLyDatumToOb *arg, TupleDesc desc,
+											  struct PLyProcedure *proc);
+extern PGDLLEXPORT void PLy_output_setup_tuple(PLyObToDatum *arg, TupleDesc desc,
+											   struct PLyProcedure *proc);
 
-extern void PLy_output_setup_record(PLyObToDatum *arg, TupleDesc desc,
-									struct PLyProcedure *proc);
+extern PGDLLEXPORT void PLy_output_setup_record(PLyObToDatum *arg, TupleDesc desc,
+												struct PLyProcedure *proc);
 
 /* conversion from Python objects to C strings --- exported for transforms */
-extern char *PLyObject_AsString(PyObject *plrv);
+extern PGDLLEXPORT char *PLyObject_AsString(PyObject *plrv);
 
 #endif							/* PLPY_TYPEIO_H */
diff --git a/src/pl/plpython/plpy_util.h b/src/pl/plpython/plpy_util.h
index 7c6577925ea..6f491b0f95b 100644
--- a/src/pl/plpython/plpy_util.h
+++ b/src/pl/plpython/plpy_util.h
@@ -8,10 +8,10 @@
 
 #include "plpython.h"
 
-extern PyObject *PLyUnicode_Bytes(PyObject *unicode);
-extern char *PLyUnicode_AsString(PyObject *unicode);
+extern PGDLLEXPORT PyObject *PLyUnicode_Bytes(PyObject *unicode);
+extern PGDLLEXPORT char *PLyUnicode_AsString(PyObject *unicode);
 
-extern PyObject *PLyUnicode_FromString(const char *s);
-extern PyObject *PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size);
+extern PGDLLEXPORT PyObject *PLyUnicode_FromString(const char *s);
+extern PGDLLEXPORT PyObject *PLyUnicode_FromStringAndSize(const char *s, Py_ssize_t size);
 
 #endif							/* PLPY_UTIL_H */
diff --git a/contrib/hstore/hstore.h b/contrib/hstore/hstore.h
index bf4a565ed9b..4713e6ea7ab 100644
--- a/contrib/hstore/hstore.h
+++ b/contrib/hstore/hstore.h
@@ -147,7 +147,7 @@ typedef struct
 	} while (0)
 
 /* DatumGetHStoreP includes support for reading old-format hstore values */
-extern HStore *hstoreUpgrade(Datum orig);
+extern PGDLLEXPORT HStore *hstoreUpgrade(Datum orig);
 
 #define DatumGetHStoreP(d) hstoreUpgrade(d)
 
@@ -168,14 +168,14 @@ typedef struct
 	bool		needfree;		/* need to pfree the value? */
 } Pairs;
 
-extern int	hstoreUniquePairs(Pairs *a, int32 l, int32 *buflen);
-extern HStore *hstorePairs(Pairs *pairs, int32 pcount, int32 buflen);
+extern PGDLLEXPORT int hstoreUniquePairs(Pairs *a, int32 l, int32 *buflen);
+extern PGDLLEXPORT HStore *hstorePairs(Pairs *pairs, int32 pcount, int32 buflen);
 
-extern size_t hstoreCheckKeyLen(size_t len);
-extern size_t hstoreCheckValLen(size_t len);
+extern PGDLLEXPORT size_t hstoreCheckKeyLen(size_t len);
+extern PGDLLEXPORT size_t hstoreCheckValLen(size_t len);
 
-extern int	hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen);
-extern Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
+extern PGDLLEXPORT int hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen);
+extern PGDLLEXPORT Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
 
 #define HStoreContainsStrategyNumber	7
 #define HStoreExistsStrategyNumber		9
@@ -194,7 +194,7 @@ extern Pairs *hstoreArrayToPairs(ArrayType *a, int *npairs);
 #if HSTORE_POLLUTE_NAMESPACE
 #define HSTORE_POLLUTE(newname_,oldname_) \
 	PG_FUNCTION_INFO_V1(oldname_);		  \
-	Datum newname_(PG_FUNCTION_ARGS);	  \
+	extern PGDLLEXPORT Datum newname_(PG_FUNCTION_ARGS);	  \
 	Datum oldname_(PG_FUNCTION_ARGS) { return newname_(fcinfo); } \
 	extern int no_such_variable
 #else
diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index 564e4fa81b8..3dd99ca6848 100644
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -176,30 +176,30 @@ typedef struct
 
 
 /* use in array iterator */
-Datum		ltree_isparent(PG_FUNCTION_ARGS);
-Datum		ltree_risparent(PG_FUNCTION_ARGS);
-Datum		ltq_regex(PG_FUNCTION_ARGS);
-Datum		ltq_rregex(PG_FUNCTION_ARGS);
-Datum		lt_q_regex(PG_FUNCTION_ARGS);
-Datum		lt_q_rregex(PG_FUNCTION_ARGS);
-Datum		ltxtq_exec(PG_FUNCTION_ARGS);
-Datum		ltxtq_rexec(PG_FUNCTION_ARGS);
-Datum		_ltq_regex(PG_FUNCTION_ARGS);
-Datum		_ltq_rregex(PG_FUNCTION_ARGS);
-Datum		_lt_q_regex(PG_FUNCTION_ARGS);
-Datum		_lt_q_rregex(PG_FUNCTION_ARGS);
-Datum		_ltxtq_exec(PG_FUNCTION_ARGS);
-Datum		_ltxtq_rexec(PG_FUNCTION_ARGS);
-Datum		_ltree_isparent(PG_FUNCTION_ARGS);
-Datum		_ltree_risparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_isparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_risparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltq_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltq_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum lt_q_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum lt_q_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltxtq_exec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltxtq_rexec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltq_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltq_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _lt_q_regex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _lt_q_rregex(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltxtq_exec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltxtq_rexec(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltree_isparent(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum _ltree_risparent(PG_FUNCTION_ARGS);
 
 /* Concatenation functions */
-Datum		ltree_addltree(PG_FUNCTION_ARGS);
-Datum		ltree_addtext(PG_FUNCTION_ARGS);
-Datum		ltree_textadd(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_addltree(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_addtext(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_textadd(PG_FUNCTION_ARGS);
 
 /* Util function */
-Datum		ltree_in(PG_FUNCTION_ARGS);
+PGDLLEXPORT Datum ltree_in(PG_FUNCTION_ARGS);
 
 bool		ltree_execute(ITEM *curitem, void *checkval,
 						  bool calcnot, bool (*chkcond) (void *checkval, ITEM *val));
diff --git a/src/test/modules/test_shm_mq/test_shm_mq.h b/src/test/modules/test_shm_mq/test_shm_mq.h
index 0310caf50bd..8f97be78d3e 100644
--- a/src/test/modules/test_shm_mq/test_shm_mq.h
+++ b/src/test/modules/test_shm_mq/test_shm_mq.h
@@ -40,6 +40,6 @@ extern void test_shm_mq_setup(int64 queue_size, int32 nworkers,
 							  shm_mq_handle **input);
 
 /* Main entrypoint for a worker. */
-extern void test_shm_mq_main(Datum) pg_attribute_noreturn();
+extern PGDLLEXPORT void test_shm_mq_main(Datum) pg_attribute_noreturn();
 
 #endif
diff --git a/src/test/modules/worker_spi/worker_spi.c b/src/test/modules/worker_spi/worker_spi.c
index b37ef8beb60..d63a7631ad2 100644
--- a/src/test/modules/worker_spi/worker_spi.c
+++ b/src/test/modules/worker_spi/worker_spi.c
@@ -46,7 +46,7 @@ PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(worker_spi_launch);
 
-void		worker_spi_main(Datum) pg_attribute_noreturn();
+PGDLLEXPORT void worker_spi_main(Datum) pg_attribute_noreturn();
 
 /* GUC variables */
 static int	worker_spi_naptime = 10;
-- 
2.37.0.3.g30cc8d0f14

From bc3f07e69bf928cd916a175f94a6fb2141eef51c Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 16 Jul 2022 13:08:46 -0700
Subject: [PATCH v3 4/4] Use hidden visibility for shared libraries where
 possible.

Author: Andres Freund <andres@anarazel.de>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
---
 src/include/c.h            |  13 +++-
 src/include/pg_config.h.in |   3 +
 src/makefiles/pgxs.mk      |   5 +-
 configure                  | 152 +++++++++++++++++++++++++++++++++++++
 configure.ac               |  13 ++++
 src/Makefile.global.in     |   2 +
 src/Makefile.shlib         |  13 ++++
 src/tools/msvc/Project.pm  |   7 --
 src/tools/msvc/Solution.pm |   1 +
 9 files changed, 197 insertions(+), 12 deletions(-)

diff --git a/src/include/c.h b/src/include/c.h
index 863a16c6a6c..2cc2784750e 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -1347,14 +1347,19 @@ extern unsigned long long strtoull(const char *str, char **endptr, int base);
 
 /*
  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
- * loadable modules and need to be callable by the core backend.  (Usually,
- * this is not necessary because our build process automatically exports
- * such symbols, but sometimes manual marking is required.)
- * No special marking is required on most ports.
+ * loadable modules and need to be callable by the core backend or other
+ * loadable modules.
+ * If the compiler knows __attribute__((visibility("*"))), we use that,
+ * unless we already have a platform-specific definition.  Otherwise,
+ * no special marking is required.
  */
 #ifndef PGDLLEXPORT
+#ifdef HAVE_VISIBILITY_ATTRIBUTE
+#define PGDLLEXPORT __attribute__((visibility("default")))
+#else
 #define PGDLLEXPORT
 #endif
+#endif
 
 /*
  * The following is used as the arg list for signal handlers.  Any ports
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 7133c3dc66b..529fb84a86c 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -700,6 +700,9 @@
 /* Define to 1 if you have the <uuid/uuid.h> header file. */
 #undef HAVE_UUID_UUID_H
 
+/* Define to 1 if your compiler knows the visibility("hidden") attribute. */
+#undef HAVE_VISIBILITY_ATTRIBUTE
+
 /* Define to 1 if you have the `wcstombs_l' function. */
 #undef HAVE_WCSTOMBS_L
 
diff --git a/src/makefiles/pgxs.mk b/src/makefiles/pgxs.mk
index 0f71fa293d0..cc62df4793b 100644
--- a/src/makefiles/pgxs.mk
+++ b/src/makefiles/pgxs.mk
@@ -101,8 +101,11 @@ endif # PGXS
 
 override CPPFLAGS := -I. -I$(srcdir) $(CPPFLAGS)
 
+# See equivalent block in Makefile.shlib
 ifdef MODULES
-override CFLAGS += $(CFLAGS_SL)
+override LDFLAGS_SL += $(CFLAGS_SL_MOD)
+override CFLAGS += $(CFLAGS_SL) $(CFLAGS_SL_MOD)
+override CXXFLAGS += $(CFLAGS_SL) $(CXXFLAGS_SL_MOD)
 endif
 
 ifdef MODULEDIR
diff --git a/configure b/configure
index 1e63c6862bc..3b752941a0c 100755
--- a/configure
+++ b/configure
@@ -741,6 +741,8 @@ CPP
 CFLAGS_SL
 BITCODE_CXXFLAGS
 BITCODE_CFLAGS
+CXXFLAGS_SL_MOD
+CFLAGS_SL_MOD
 CFLAGS_VECTORIZE
 CFLAGS_UNROLL_LOOPS
 PERMIT_DECLARATION_AFTER_STATEMENT
@@ -6302,6 +6304,154 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
+  #
+  # If the compiler knows how to hide symbols, set CFLAGS_SL_MOD
+  # to the switch needed for that, and define HAVE_VISIBILITY_ATTRIBUTE.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MOD} -fvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MOD="${CFLAGS_SL_MOD} -fvisibility=hidden"
+fi
+
+
+  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+
+$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
+
+  fi
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MOD} -fvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MOD="${CXXFLAGS_SL_MOD} -fvisibility=hidden"
+fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MOD" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MOD... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MOD} -fvisibility-inlines-hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
+  CXXFLAGS_SL_MOD="${CXXFLAGS_SL_MOD} -fvisibility-inlines-hidden"
+fi
+
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
@@ -6860,6 +7010,8 @@ fi
 
 
 
+
+
 # Determine flags used to emit bitcode for JIT inlining.
 # 1. We must duplicate any behaviour-changing compiler flags used above,
 # to keep compatibility with the compiler used for normal Postgres code.
diff --git a/configure.ac b/configure.ac
index 71191f14ad7..478da1971e7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -525,6 +525,17 @@ if test "$GCC" = yes -a "$ICC" = no; then
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
   #
+  # If the compiler knows how to hide symbols, set CFLAGS_SL_MOD
+  # to the switch needed for that, and define HAVE_VISIBILITY_ATTRIBUTE.
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MOD, [-fvisibility=hidden])
+  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+     AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
+               [Define to 1 if your compiler knows the visibility("hidden") attribute.])
+  fi
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MOD, [-fvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MOD, [-fvisibility-inlines-hidden])
+  #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
   # switches, so we have to test for the positive form and if that works,
@@ -573,6 +584,8 @@ fi
 
 AC_SUBST(CFLAGS_UNROLL_LOOPS)
 AC_SUBST(CFLAGS_VECTORIZE)
+AC_SUBST(CFLAGS_SL_MOD)
+AC_SUBST(CXXFLAGS_SL_MOD)
 
 # Determine flags used to emit bitcode for JIT inlining.
 # 1. We must duplicate any behaviour-changing compiler flags used above,
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 138d66ac006..2d58f1d7f49 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -258,6 +258,8 @@ SUN_STUDIO_CC = @SUN_STUDIO_CC@
 CXX = @CXX@
 CFLAGS = @CFLAGS@
 CFLAGS_SL = @CFLAGS_SL@
+CFLAGS_SL_MOD = @CFLAGS_SL_MOD@
+CXXFLAGS_SL_MOD = @CXXFLAGS_SL_MOD@
 CFLAGS_UNROLL_LOOPS = @CFLAGS_UNROLL_LOOPS@
 CFLAGS_VECTORIZE = @CFLAGS_VECTORIZE@
 CFLAGS_SSE42 = @CFLAGS_SSE42@
diff --git a/src/Makefile.shlib b/src/Makefile.shlib
index 6df96c634b6..5ec8209cc79 100644
--- a/src/Makefile.shlib
+++ b/src/Makefile.shlib
@@ -218,6 +218,19 @@ ifeq ($(PORTNAME), win32)
 endif
 
 
+# If the shared library doesn't have an export file, mark all symbols not
+# explicitly exported using PGDLLEXPORT as hidden. We can't pass these flags
+# when building a library with explicit exports, as the symbols would be
+# hidden before the linker script / exported symbol list takes effect.
+#
+# This is duplicated in pgxs.mk for MODULES style libraries.
+ifeq ($(SHLIB_EXPORTS),)
+  # LDFLAGS_SL addition not strictly needed, CFLAGS used everywhere, but ...
+  override LDFLAGS_SL += $(CFLAGS_SL_MOD)
+  override CFLAGS += $(CFLAGS_SL_MOD)
+  override CXXFLAGS += $(CXXFLAGS_SL_MOD)
+endif
+
 
 ##
 ## BUILD
diff --git a/src/tools/msvc/Project.pm b/src/tools/msvc/Project.pm
index 570bab563a7..b24a2a98155 100644
--- a/src/tools/msvc/Project.pm
+++ b/src/tools/msvc/Project.pm
@@ -419,13 +419,6 @@ sub Save
 {
 	my ($self) = @_;
 
-	# If doing DLL and haven't specified a DEF file, do a full export of all symbols
-	# in the project.
-	if ($self->{type} eq "dll" && !$self->{def})
-	{
-		$self->FullExportDLL($self->{name} . ".lib");
-	}
-
 	# Warning 4197 is about double exporting, disable this per
 	# http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=99193
 	$self->DisableLinkerWarnings('4197') if ($self->{platform} eq 'x64');
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index fa32dc371dc..f2427008df6 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -429,6 +429,7 @@ sub GenerateFiles
 		HAVE_WINLDAP_H                           => undef,
 		HAVE_WCSTOMBS_L                          => 1,
 		HAVE_WCTYPE_H                            => 1,
+		HAVE_VISIBILITY_ATTRIBUTE                => undef,
 		HAVE_WRITEV                              => undef,
 		HAVE_X509_GET_SIGNATURE_NID              => 1,
 		HAVE_X86_64_POPCNTQ                      => undef,
-- 
2.37.0.3.g30cc8d0f14

From 713236eb696b6b60bbde3582d0fd31f1de23d7b9 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Mon, 18 Jul 2022 15:05:58 -0700
Subject: [PATCH v4] configure: Check if -fvisibility is supported for all
 compilers.

---
 configure    | 305 ++++++++++++++++++++++++++-------------------------
 configure.ac |  31 ++++--
 2 files changed, 177 insertions(+), 159 deletions(-)

diff --git a/configure b/configure
index a4f4d321fb7..df68b86b09b 100755
--- a/configure
+++ b/configure
@@ -6304,154 +6304,6 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
-  #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CFLAGS=$CFLAGS
-pgac_save_CC=$CC
-CC=${CC}
-CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_c_werror_flag=$ac_c_werror_flag
-ac_c_werror_flag=yes
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_c_werror_flag=$ac_save_c_werror_flag
-CFLAGS="$pgac_save_CFLAGS"
-CC="$pgac_save_CC"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
-  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-
-$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
-
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-fi
-
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
@@ -7007,6 +6859,163 @@ fi
 
 fi
 
+# If the compiler knows how to hide symbols add the switch needed for that
+# to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done outside of the compiler specific sections above, as at least
+# some versions of all of the currently supported compilers support
+# -fvisibility=hidden.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports -fvisibility=hidden but uses a different syntax to
+# mark a symbol as exported.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+
+if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+
+$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
+
+fi
+# For C++ we additionally want -fvisibility-inlines-hidden
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+fi
+
+
 
 
 
diff --git a/configure.ac b/configure.ac
index 5bd29a4d2f2..04c3e56bf52 100644
--- a/configure.ac
+++ b/configure.ac
@@ -525,17 +525,6 @@ if test "$GCC" = yes -a "$ICC" = no; then
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
   #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-     AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
-               [Define to 1 if your compiler knows the visibility("hidden") attribute.])
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
-  #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
   # switches, so we have to test for the positive form and if that works,
@@ -582,6 +571,26 @@ elif test "$PORTNAME" = "aix"; then
   PGAC_PROG_CXX_CFLAGS_OPT([-qlonglong])
 fi
 
+# If the compiler knows how to hide symbols add the switch needed for that
+# to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done outside of the compiler specific sections above, as at least
+# some versions of all of the currently supported compilers support
+# -fvisibility=hidden.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports -fvisibility=hidden but uses a different syntax to
+# mark a symbol as exported.
+PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
+if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
+   AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
+             [Define to 1 if your compiler knows the visibility("hidden") attribute.])
+fi
+# For C++ we additionally want -fvisibility-inlines-hidden
+PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
+PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
+
 AC_SUBST(CFLAGS_UNROLL_LOOPS)
 AC_SUBST(CFLAGS_VECTORIZE)
 AC_SUBST(CFLAGS_SL_MODULE)
-- 
2.37.0.3.g30cc8d0f14

From d00dbc2188893a0f0f6b533aaee5733a22568527 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 20 Aug 2022 08:43:28 -0700
Subject: [PATCH v5 1/2] aix: No need to use mkldexport when we want to export
 all symbols

When building a shared library with an exports.txt there's no need to build an
intermediary static library, we can just pass -Wl,-bE:... when generating the
.so.

When building a shared library without an exports.txt, there's no need to call
mkldexport.sh to export all symbols, because all symbols are exported anyway,
and we don't need the export file on the import side (like we do for
postgres.imp).

This makes building .so's on aix a lot more similar to building on other
platforms. In particular, we don't create and remove a .a of the same name but
different contents anymore.
---
 src/makefiles/Makefile.aix |  8 ++-----
 src/Makefile.shlib         | 45 +++++++++++++++-----------------------
 2 files changed, 20 insertions(+), 33 deletions(-)

diff --git a/src/makefiles/Makefile.aix b/src/makefiles/Makefile.aix
index 9408c1e2913..56d7f22aff6 100644
--- a/src/makefiles/Makefile.aix
+++ b/src/makefiles/Makefile.aix
@@ -38,9 +38,5 @@ endif
 MKLDEXPORT_DIR=src/backend/port/aix
 MKLDEXPORT=$(top_srcdir)/$(MKLDEXPORT_DIR)/mkldexport.sh
 
-%.exp: %.o
-	$(MKLDEXPORT) $^ >$@
-
-# Rule for building a shared library from a single .o file
-%$(DLSUFFIX): %.o %.exp
-	$(CC) $(CFLAGS) $*.o $(LDFLAGS) $(LDFLAGS_SL) -o $@ -Wl,-bE:$*.exp $(BE_DLLLIBS)
+%$(DLSUFFIX): %.o
+	$(CC) $(CFLAGS) $*.o $(LDFLAGS) $(LDFLAGS_SL) -o $@ $(BE_DLLLIBS)
diff --git a/src/Makefile.shlib b/src/Makefile.shlib
index 1e09ab8ea62..db466b3b845 100644
--- a/src/Makefile.shlib
+++ b/src/Makefile.shlib
@@ -107,12 +107,17 @@ override CPPFLAGS += -DSO_MAJOR_VERSION=$(SO_MAJOR_VERSION)
 endif
 
 ifeq ($(PORTNAME), aix)
+  LINK.shared		= $(COMPILER)
   ifdef SO_MAJOR_VERSION
     shlib		= lib$(NAME)$(DLSUFFIX).$(SO_MAJOR_VERSION)
   endif
   haslibarule   = yes
   # $(exports_file) is also usable as an import file
   exports_file		= lib$(NAME).exp
+  BUILD.exports		= ( echo '\#! $(shlib)'; $(AWK) '/^[^\#]/ {printf "%s\n",$$1}' $< ) > $@
+  ifneq (,$(SHLIB_EXPORTS))
+    LINK.shared		+= -Wl,-bE:$(exports_file)
+  endif
 endif
 
 ifeq ($(PORTNAME), darwin)
@@ -259,9 +264,15 @@ $(stlib): $(OBJS) | $(SHLIB_PREREQS)
 	touch $@
 endif #haslibarule
 
+# AIX wraps shared libraries inside a static library, can be used both
+# for static and shared linking
+ifeq ($(PORTNAME), aix)
+$(stlib): $(shlib)
+	rm -f $(stlib)
+	$(AR) $(AROPT) $(stlib) $(shlib)
+endif # aix
 
 ifeq (,$(filter cygwin win32,$(PORTNAME)))
-ifneq ($(PORTNAME), aix)
 
 # Normal case
 $(shlib): $(OBJS) | $(SHLIB_PREREQS)
@@ -274,9 +285,12 @@ ifneq ($(shlib), $(shlib_major))
 endif
 # Make sure we have a link to a name without any version numbers
 ifneq ($(shlib), $(shlib_bare))
+# except on AIX, where that's not a thing
+ifneq ($(PORTNAME), aix)
 	rm -f $(shlib_bare)
 	$(LN_S) $(shlib) $(shlib_bare)
-endif
+endif # aix
+endif # shlib_bare
 endif # shlib_major
 
 # Where possible, restrict the symbols exported by the library to just the
@@ -285,36 +299,13 @@ endif # shlib_major
 # libpgport along with libpq.
 ifneq (,$(SHLIB_EXPORTS))
 ifdef BUILD.exports
-$(shlib): $(SHLIB_EXPORTS:%.txt=%.list)
+$(shlib): $(exports_file)
 
-$(SHLIB_EXPORTS:%.txt=%.list): %.list: %.txt
+$(exports_file): $(SHLIB_EXPORTS)
 	$(BUILD.exports)
 endif
 endif
 
-else # PORTNAME == aix
-
-# AIX case
-
-# See notes in src/backend/parser/Makefile about the following two rules
-$(stlib): $(shlib)
-	touch $@
-
-$(shlib): $(OBJS) | $(SHLIB_PREREQS)
-	rm -f $(stlib)
-	$(LINK.static) $(stlib) $^
-	$(RANLIB) $(stlib)
-ifeq (,$(SHLIB_EXPORTS))
-	$(MKLDEXPORT) $(stlib) $(shlib) >$(exports_file)
-else
-	( echo '#! $(shlib)'; $(AWK) '/^[^#]/ {printf "%s\n",$$1}' ${srcdir}/$(SHLIB_EXPORTS) ) >$(exports_file)
-endif
-	$(COMPILER) -o $(shlib) $(stlib) -Wl,-bE:$(exports_file) $(LDFLAGS) $(LDFLAGS_SL) $(SHLIB_LINK)
-	rm -f $(stlib)
-	$(AR) $(AROPT) $(stlib) $(shlib)
-
-endif # PORTNAME == aix
-
 else # PORTNAME == cygwin || PORTNAME == win32
 
 ifeq ($(PORTNAME), cygwin)
-- 
2.37.0.3.g30cc8d0f14

From 4a3eef98c0f0fb5b4b272525fa544973fe3a2eaa Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Thu, 1 Sep 2022 14:10:07 -0700
Subject: [PATCH v5 2/2] configure: Expand -fvisibility checks to more
 compilers, test for -qvisibility

It looks like icc and sunpro both support -fvisibility=hidden and xlc supports
-qvisibility=hidden. I tested this on AIX and solaris with their proprietary
compilers as well as gcc, and with gcc or clang on freebsd, linux, macos,
netbsd and openbsd.
---
 configure    | 398 ++++++++++++++++++++++++++++++++-------------------
 configure.ac |  37 +++--
 2 files changed, 276 insertions(+), 159 deletions(-)

diff --git a/configure b/configure
index a268780c5db..68811612d38 100755
--- a/configure
+++ b/configure
@@ -6302,154 +6302,6 @@ if test x"$pgac_cv_prog_CC_cflags__ftree_vectorize" = x"yes"; then
 fi
 
 
-  #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CFLAGS=$CFLAGS
-pgac_save_CC=$CC
-CC=${CC}
-CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_c_werror_flag=$ac_c_werror_flag
-ac_c_werror_flag=yes
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_c_werror_flag=$ac_save_c_werror_flag
-CFLAGS="$pgac_save_CFLAGS"
-CC="$pgac_save_CC"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
-  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-
-$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
-
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
-fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
-$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
-if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  pgac_save_CXXFLAGS=$CXXFLAGS
-pgac_save_CXX=$CXX
-CXX=${CXX}
-CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-ac_cxx_werror_flag=yes
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_cxx_try_compile "$LINENO"; then :
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
-else
-  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-CXXFLAGS="$pgac_save_CXXFLAGS"
-CXX="$pgac_save_CXX"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
-$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
-if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
-  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
-fi
-
   #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
@@ -7005,6 +6857,256 @@ fi
 
 fi
 
+# If the compiler knows how to hide symbols, add the switch needed for that to
+# CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done separately from the above because -fvisibility is supported by
+# quite a few different compilers, making the required repetition bothersome.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports one of the supported variants of -fvisibility=hidden
+# but uses a different syntax to mark a symbol as exported.
+if test "$GCC" = yes -o "$SUN_STUDIO_CC" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CC} supports -fvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CC_cflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__fvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility=hidden"
+fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -fvisibility-inlines-hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__fvisibility_inlines_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -fvisibility-inlines-hidden"
+fi
+
+elif test "$PORTNAME" = "aix"; then
+  # Note that xlc accepts -fvisibility=hidden as a file.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -qvisibility=hidden, for CFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CC} supports -qvisibility=hidden, for CFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CC_cflags__qvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${CFLAGS_SL_MODULE} -qvisibility=hidden"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_prog_CC_cflags__qvisibility_hidden=yes
+else
+  pgac_cv_prog_CC_cflags__qvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+CC="$pgac_save_CC"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__qvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__qvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__qvisibility_hidden" = x"yes"; then
+  CFLAGS_SL_MODULE="${CFLAGS_SL_MODULE} -qvisibility=hidden"
+fi
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CXX} supports -qvisibility=hidden, for CXXFLAGS_SL_MODULE" >&5
+$as_echo_n "checking whether ${CXX} supports -qvisibility=hidden, for CXXFLAGS_SL_MODULE... " >&6; }
+if ${pgac_cv_prog_CXX_cxxflags__qvisibility_hidden+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CXXFLAGS=$CXXFLAGS
+pgac_save_CXX=$CXX
+CXX=${CXX}
+CXXFLAGS="${CXXFLAGS_SL_MODULE} -qvisibility=hidden"
+ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+ac_cxx_werror_flag=yes
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  pgac_cv_prog_CXX_cxxflags__qvisibility_hidden=yes
+else
+  pgac_cv_prog_CXX_cxxflags__qvisibility_hidden=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+CXXFLAGS="$pgac_save_CXXFLAGS"
+CXX="$pgac_save_CXX"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" >&5
+$as_echo "$pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" >&6; }
+if test x"$pgac_cv_prog_CXX_cxxflags__qvisibility_hidden" = x"yes"; then
+  CXXFLAGS_SL_MODULE="${CXXFLAGS_SL_MODULE} -qvisibility=hidden"
+fi
+
+fi
+
+if test -n "${CFLAGS_SL_MODULE}"; then
+
+$as_echo "#define HAVE_VISIBILITY_ATTRIBUTE 1" >>confdefs.h
+
+fi
+
 
 
 
diff --git a/configure.ac b/configure.ac
index 993b5d5cb0a..6f041a6dd2e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -525,17 +525,6 @@ if test "$GCC" = yes -a "$ICC" = no; then
   # Optimization flags for specific files that benefit from vectorization
   PGAC_PROG_CC_VAR_OPT(CFLAGS_VECTORIZE, [-ftree-vectorize])
   #
-  # If the compiler knows how to hide symbols add the switch needed for that
-  # to CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
-  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
-  if test "$pgac_cv_prog_CC_cflags__fvisibility_hidden" = yes; then
-     AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
-               [Define to 1 if your compiler knows the visibility("hidden") attribute.])
-  fi
-  # For C++ we additionally want -fvisibility-inlines-hidden
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
-  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
-  #
   # The following tests want to suppress various unhelpful warnings by adding
   # -Wno-foo switches.  But gcc won't complain about unrecognized -Wno-foo
   # switches, so we have to test for the positive form and if that works,
@@ -582,6 +571,32 @@ elif test "$PORTNAME" = "aix"; then
   PGAC_PROG_CXX_CFLAGS_OPT([-qlonglong])
 fi
 
+# If the compiler knows how to hide symbols, add the switch needed for that to
+# CFLAGS_SL_MODULE and define HAVE_VISIBILITY_ATTRIBUTE.
+#
+# This is done separately from the above because -fvisibility is supported by
+# quite a few different compilers, making the required repetition bothersome.
+#
+# We might need to add a separate test to check if
+# __attribute__((visibility("hidden"))) is supported, if we encounter a
+# compiler that supports one of the supported variants of -fvisibility=hidden
+# but uses a different syntax to mark a symbol as exported.
+if test "$GCC" = yes -o "$SUN_STUDIO_CC" = yes ; then
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-fvisibility=hidden])
+  # For C++ we additionally want -fvisibility-inlines-hidden
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-fvisibility-inlines-hidden])
+elif test "$PORTNAME" = "aix"; then
+  # Note that xlc accepts -fvisibility=hidden as a file.
+  PGAC_PROG_CC_VAR_OPT(CFLAGS_SL_MODULE, [-qvisibility=hidden])
+  PGAC_PROG_VARCXX_VARFLAGS_OPT(CXX, CXXFLAGS_SL_MODULE, [-qvisibility=hidden])
+fi
+
+if test -n "${CFLAGS_SL_MODULE}"; then
+  AC_DEFINE([HAVE_VISIBILITY_ATTRIBUTE], 1,
+            [Define to 1 if your compiler knows the visibility("hidden") attribute.])
+fi
+
 AC_SUBST(CFLAGS_UNROLL_LOOPS)
 AC_SUBST(CFLAGS_VECTORIZE)
 AC_SUBST(CFLAGS_SL_MODULE)
-- 
2.37.0.3.g30cc8d0f14