[glade/glade-3-36.msvc: 12/18] gladeui/meson.build: Override GLADEUI_EXPORTS as needed

[Chun-wei Fan <fanchunwei src gnome org>]

commit a91f0dc9ec5e9f3a7cd436c3e8d6e6e2e90c86ab
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Jun 3 19:11:37 2020 +0800

    gladeui/meson.build: Override GLADEUI_EXPORTS as needed
    
    On Visual Studio-style compilers, define GLADEUI_EXPORTS to be
    __declspec(dllexport) so that we can export the symbols from the gladeui
    DLL as needed.
    
    This will also enable us to build the introspection files, as well as
    the various plugins and tools in glade properly

 gladeui/meson.build | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/gladeui/meson.build b/gladeui/meson.build
index b9555b9e..b27278c1 100644
--- a/gladeui/meson.build
+++ b/gladeui/meson.build
@@ -183,6 +183,7 @@ if enable_mac_integration
   endif
 endif
 
+extra_cflags = []
 if glade_system == 'windows'
   rc = configure_file(
     input: 'gladeui.rc.in',
@@ -192,6 +193,10 @@ if glade_system == 'windows'
 
   sources += windows.compile_resources(rc)
 
+  if cc.get_argument_syntax() == 'msvc'
+    extra_cflags += '-DGLADEUI_EXPORTS=__declspec(dllexport)'
+  endif
+
   ldflags += cc.get_supported_link_arguments([
     # gmodule-export-2.0 on windows does not include -export-dynamic flag
     '-export-dynamic',
@@ -205,7 +210,7 @@ libgladeui = shared_library(
   sources: sources + enum_sources + marshal_sources + private_headers + headers,
   include_directories: top_inc,
   dependencies: deps + private_deps,
-  c_args: common_c_flags,
+  c_args: common_c_flags + extra_cflags,
   link_args: ldflags,
   install: true,
 )