[gnome-builder] build: setup visibility flags without applying them

[Christian Hergert <chergert src gnome org>]

commit 5a9bd4c0917188cc573f1ce3a6185750c6f28a46
Author: Christian Hergert <chergert redhat com>
Date:   Thu Mar 22 03:23:23 2018 -0700

    build: setup visibility flags without applying them
    
    This adds the bits we need to do visibility flags, but does not
    yet apply the default visibility.

 meson.build            | 23 +++++++++++++++++++----
 src/libide/meson.build |  3 +++
 2 files changed, 22 insertions(+), 4 deletions(-)
---
diff --git a/meson.build b/meson.build
index 738359f5f..15f7ec7fc 100644
--- a/meson.build
+++ b/meson.build
@@ -149,10 +149,25 @@ foreach arg: test_c_args
     global_c_args += arg
   endif
 endforeach
-add_project_arguments(
-  global_c_args,
-  language: 'c'
-)
+
+# Detect and set symbol visibility
+hidden_visibility_args = []
+if get_option('default_library') != 'static'
+  if host_machine.system() == 'windows'
+    config_h.set('DLL_EXPORT', true)
+    if cc.get_id() == 'msvc'
+      config_h.set('_IDE_EXTERN', '__declspec(dllexport) extern')
+    elif cc.has_argument('-fvisibility=hidden')
+      config_h.set('_IDE_EXTERN', '__attribute__((visibility("default"))) __declspec(dllexport) extern')
+      hidden_visibility_args = ['-fvisibility=hidden']
+    endif
+  elif cc.has_argument('-fvisibility=hidden')
+    config_h.set('_IDE_EXTERN', '__attribute__((visibility("default"))) extern')
+    hidden_visibility_args = ['-fvisibility=hidden']
+  endif
+endif
+
+add_project_arguments(global_c_args, language: 'c')
 
 global_link_args = []
 test_link_args = [
diff --git a/src/libide/meson.build b/src/libide/meson.build
index 055801b9b..4d5349094 100644
--- a/src/libide/meson.build
+++ b/src/libide/meson.build
@@ -217,6 +217,9 @@ if get_option('with_editorconfig')
   libide_deps += libeditorconfig_dep
 endif
 
+# Limit visibility to public API
+# libide_args += hidden_visibility_args
+
 libide = shared_library('ide-' + libide_api_version,
   libide_resources + libide_icons_resources + libide_sources,
   dependencies: libide_deps,