[libsoup/wip/nacho/soup-extern] Declare a SOUP_VAR to externalize variables

[Ignacio Casal Quinteiro <icq src gnome org>]

commit e2d421ef2fb05d5b5810de5692aa8392c7e4f641
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Tue Oct 27 13:22:55 2015 +0100

    Declare a SOUP_VAR to externalize variables
    
    This is needed to properly externalize the variables
    on windows. Since we need to handle dllexport vs dllimport
    
    https://bugzilla.gnome.org/show_bug.cgi?id=757146

 libsoup/soup-method.h     |   45 +++++++++++++++------------------------------
 libsoup/soup-version.h.in |   19 +++++++++++++++++++
 2 files changed, 34 insertions(+), 30 deletions(-)
---
diff --git a/libsoup/soup-method.h b/libsoup/soup-method.h
index a0952ba..cec59e3 100644
--- a/libsoup/soup-method.h
+++ b/libsoup/soup-method.h
@@ -58,37 +58,22 @@ G_BEGIN_DECLS
 /* Do not use these variables directly; use the macros above, which
  * ensure that they get initialized properly.
  */
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_OPTIONS;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_GET;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_HEAD;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_POST;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_PUT;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_DELETE;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_TRACE;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_CONNECT;
+SOUP_VAR gpointer _SOUP_METHOD_OPTIONS;
+SOUP_VAR gpointer _SOUP_METHOD_GET;
+SOUP_VAR gpointer _SOUP_METHOD_HEAD;
+SOUP_VAR gpointer _SOUP_METHOD_POST;
+SOUP_VAR gpointer _SOUP_METHOD_PUT;
+SOUP_VAR gpointer _SOUP_METHOD_DELETE;
+SOUP_VAR gpointer _SOUP_METHOD_TRACE;
+SOUP_VAR gpointer _SOUP_METHOD_CONNECT;
 
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_PROPFIND;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_PROPPATCH;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_MKCOL;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_COPY;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_MOVE;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_LOCK;
-SOUP_AVAILABLE_IN_2_4
-gpointer _SOUP_METHOD_UNLOCK;
+SOUP_VAR gpointer _SOUP_METHOD_PROPFIND;
+SOUP_VAR gpointer _SOUP_METHOD_PROPPATCH;
+SOUP_VAR gpointer _SOUP_METHOD_MKCOL;
+SOUP_VAR gpointer _SOUP_METHOD_COPY;
+SOUP_VAR gpointer _SOUP_METHOD_MOVE;
+SOUP_VAR gpointer _SOUP_METHOD_LOCK;
+SOUP_VAR gpointer _SOUP_METHOD_UNLOCK;
 
 G_END_DECLS
 
diff --git a/libsoup/soup-version.h.in b/libsoup/soup-version.h.in
index 3443ab3..c9661dd 100644
--- a/libsoup/soup-version.h.in
+++ b/libsoup/soup-version.h.in
@@ -30,6 +30,25 @@ G_BEGIN_DECLS
 #define _SOUP_EXTERN extern
 #endif
 
+/* We prefix variable declarations so they can
+ * properly get exported in Windows DLLs.
+ */
+#ifndef SOUP_VAR
+#  ifdef G_PLATFORM_WIN32
+#    ifdef LIBSOUP_COMPILATION
+#      ifdef DLL_EXPORT
+#        define SOUP_VAR __declspec(dllexport)
+#      else /* !DLL_EXPORT */
+#        define SOUP_VAR extern
+#      endif /* !DLL_EXPORT */
+#    else /* !SOUP_COMPILATION */
+#      define SOUP_VAR extern __declspec(dllimport)
+#    endif /* !LIBSOUP_COMPILATION */
+#  else /* !G_PLATFORM_WIN32 */
+#    define SOUP_VAR _SOUP_EXTERN
+#  endif /* !G_PLATFORM_WIN32 */
+#endif /* SOUP_VAR */
+
 /* Deprecation / Availability macros */
 
 #define SOUP_ENCODE_VERSION(major,minor) ((major) << 16 | (minor) << 8)