[gspell/wip/misc] Replace _GSPELL_EXTERN by G_MODULE_EXPORT

[Sébastien Wilmet <swilmet src gnome org>]

commit ea38c97bea707127e96ea66bbe832414e00c1306
Author: Sébastien Wilmet <swilmet informatique-libre be>
Date:   Tue Aug 16 16:00:00 2022 +0200

    Replace _GSPELL_EXTERN by G_MODULE_EXPORT
    
    Like how it is done in the Amtk library.
    To simplify things.

 configure.ac                  | 48 +++++++++++++++----------------------------
 gspell/gspell-enum-types.h.in |  2 +-
 gspell/gspell-version.h       | 16 ++++++---------
 3 files changed, 23 insertions(+), 43 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index cac457f..641e8d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -134,39 +134,23 @@ AX_CODE_COVERAGE
 AX_REQUIRE_DEFINED([AX_VALGRIND_CHECK])
 AX_VALGRIND_CHECK
 
-# Symbol visibility handling.
-#
-# This requires to #include config.h in every *.c file where there is a public
-# symbol. As a simpler rule, it's easier to #include config.h in all gspell/*.c
-# files, to be sure that we don't miss any public symbol.
+# Check if the compiler supports -fvisibility=hidden
+SAVED_CFLAGS="${CFLAGS}"
+CFLAGS="-fvisibility=hidden"
+AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
+AC_TRY_COMPILE([], [return 0],
+               AC_MSG_RESULT(yes)
+               enable_fvisibility_hidden=yes,
+               AC_MSG_RESULT(no)
+               enable_fvisibility_hidden=no)
+CFLAGS="${SAVED_CFLAGS}"
+
 GSPELL_HIDDEN_VISIBILITY_CFLAGS=""
-case "$host" in
-    *-*-mingw*)
-        dnl on mingw32 we do -fvisibility=hidden and __declspec(dllexport)
-        AC_DEFINE([_GSPELL_EXTERN], [__attribute__((visibility("default"))) __declspec(dllexport) extern],
-                  [defines how to decorate public symbols while building])
-        GSPELL_HIDDEN_VISIBILITY_CFLAGS="-fvisibility=hidden"
-        ;;
-    *)
-        dnl on other compilers, check if we can do -fvisibility=hidden
-        SAVED_CFLAGS="${CFLAGS}"
-        CFLAGS="-fvisibility=hidden"
-        AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
-        AC_TRY_COMPILE([], [return 0],
-                       AC_MSG_RESULT(yes)
-                       enable_fvisibility_hidden=yes,
-                       AC_MSG_RESULT(no)
-                       enable_fvisibility_hidden=no)
-        CFLAGS="${SAVED_CFLAGS}"
-
-        AS_IF([test "${enable_fvisibility_hidden}" = "yes"], [
-            AC_DEFINE([_GSPELL_EXTERN], [__attribute__((visibility("default"))) extern],
-                      [defines how to decorate public symbols while building])
-            GSPELL_HIDDEN_VISIBILITY_CFLAGS="-fvisibility=hidden"
-        ])
-        ;;
-esac
-AC_SUBST(GSPELL_HIDDEN_VISIBILITY_CFLAGS)
+if test "x${enable_fvisibility_hidden}" = "xyes"
+then
+       GSPELL_HIDDEN_VISIBILITY_CFLAGS="-fvisibility=hidden"
+fi
+AC_SUBST([GSPELL_HIDDEN_VISIBILITY_CFLAGS])
 
 # Check for Mac OS X platform
 AC_MSG_CHECKING([for Mac OS X platform])
diff --git a/gspell/gspell-enum-types.h.in b/gspell/gspell-enum-types.h.in
index 5054d4b..9f0d92c 100644
--- a/gspell/gspell-enum-types.h.in
+++ b/gspell/gspell-enum-types.h.in
@@ -21,7 +21,7 @@ G_BEGIN_DECLS
 /*** BEGIN enumeration-production ***/
 #define GSPELL_TYPE_@ENUMSHORT@ (@enum_name@_get_type())
 
-_GSPELL_EXTERN
+G_MODULE_EXPORT
 GType @enum_name@_get_type (void);
 
 /*** END enumeration-production ***/
diff --git a/gspell/gspell-version.h b/gspell/gspell-version.h
index 1f151d1..ce7305c 100644
--- a/gspell/gspell-version.h
+++ b/gspell/gspell-version.h
@@ -1,7 +1,7 @@
 /*
  * This file is part of gspell, a spell-checking library.
  *
- * Copyright 2017 - Sébastien Wilmet
+ * Copyright 2017, 2022 - Sébastien Wilmet
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -24,18 +24,14 @@
 #error "Only <gspell/gspell.h> can be included directly."
 #endif
 
-#include <glib.h>
+#include <gmodule.h>
 
 G_BEGIN_DECLS
 
-#ifndef _GSPELL_EXTERN
-#define _GSPELL_EXTERN extern
-#endif
-
-#define GSPELL_AVAILABLE_IN_ALL _GSPELL_EXTERN
-#define GSPELL_AVAILABLE_IN_1_2 _GSPELL_EXTERN
-#define GSPELL_AVAILABLE_IN_1_4 _GSPELL_EXTERN
-#define GSPELL_AVAILABLE_IN_1_6 _GSPELL_EXTERN
+#define GSPELL_AVAILABLE_IN_ALL G_MODULE_EXPORT
+#define GSPELL_AVAILABLE_IN_1_2 G_MODULE_EXPORT
+#define GSPELL_AVAILABLE_IN_1_4 G_MODULE_EXPORT
+#define GSPELL_AVAILABLE_IN_1_6 G_MODULE_EXPORT
 
 G_END_DECLS