[template-glib] expr-eval: use GITypelib to access symbol pointer

[Christian Hergert <chergert src gnome org>]

commit 2ea9b011afaa2916fcbe346edc9a7f0e2c230d03
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 6 14:40:25 2022 -0700

    expr-eval: use GITypelib to access symbol pointer

 src/meson.build       |  1 -
 src/tmpl-expr-eval.c  | 14 ++++++++++----
 src/tmpl-gi-private.h |  5 +++++
 src/tmpl-gi.c         | 22 ++++++++++++++++++++++
 4 files changed, 37 insertions(+), 5 deletions(-)
---
diff --git a/src/meson.build b/src/meson.build
index 8b9da7c..7ba2c62 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -64,7 +64,6 @@ libtemplate_glib_public_sources = [
 
 libtemplate_glib_deps = [
   dependency('gio-2.0'),
-  dependency('gmodule-2.0'),
   dependency('gobject-introspection-1.0'),
   cc.find_library('m', required: false),
 ]
diff --git a/src/tmpl-expr-eval.c b/src/tmpl-expr-eval.c
index 723bca7..39af2a1 100644
--- a/src/tmpl-expr-eval.c
+++ b/src/tmpl-expr-eval.c
@@ -1016,15 +1016,21 @@ tmpl_expr_gi_call_eval (TmplExprGiCall  *node,
       (base_info = g_value_get_boxed (&left)) &&
       g_base_info_get_type (base_info) == GI_INFO_TYPE_OBJECT)
     {
-      const char *type_init = g_object_info_get_type_init ((GIObjectInfo *)base_info);
-      GType (*get_type) (void) = NULL;
+      TmplGTypeFunc gtype_func = tmpl_gi_get_gtype_func (base_info);
 
-      if ((get_type = dlsym (NULL, type_init)))
+      if (gtype_func != NULL &&
+          (type = gtype_func ()) &&
+          g_type_is_a (type, G_TYPE_OBJECT))
         {
-          type = get_type ();
           object = NULL;
           goto lookup_for_object;
         }
+
+      g_set_error (error,
+                   TMPL_ERROR,
+                   TMPL_ERROR_NOT_AN_OBJECT,
+                   "Failed to locate GType function for object");
+      goto cleanup;
     }
 
   if (!G_VALUE_HOLDS_OBJECT (&left))
diff --git a/src/tmpl-gi-private.h b/src/tmpl-gi-private.h
index ed73d17..483ab5f 100644
--- a/src/tmpl-gi-private.h
+++ b/src/tmpl-gi-private.h
@@ -24,6 +24,8 @@ G_BEGIN_DECLS
 #define TMPL_TYPE_TYPELIB   (tmpl_typelib_get_type())
 #define TMPL_TYPE_BASE_INFO (tmpl_base_info_get_type())
 
+typedef GType (*TmplGTypeFunc) (void);
+
 GType    tmpl_typelib_get_type         (void);
 GType    tmpl_base_info_get_type       (void);
 gboolean tmpl_gi_argument_from_g_value (const GValue  *value,
@@ -36,6 +38,9 @@ gboolean tmpl_gi_argument_to_g_value   (GValue        *value,
                                         GIArgument    *arg,
                                         GITransfer     xfer,
                                         GError       **error);
+TmplGTypeFunc
+         tmpl_gi_get_gtype_func        (GIBaseInfo    *base_info);
+
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (GIBaseInfo, g_base_info_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (GIArgInfo, g_base_info_unref)
diff --git a/src/tmpl-gi.c b/src/tmpl-gi.c
index 709e49e..5db8572 100644
--- a/src/tmpl-gi.c
+++ b/src/tmpl-gi.c
@@ -479,3 +479,25 @@ tmpl_gi_argument_to_g_value (GValue      *value,
 
   return FALSE;
 }
+
+TmplGTypeFunc
+tmpl_gi_get_gtype_func (GIBaseInfo *base_info)
+{
+  GITypelib *typelib;
+  const char *symbol_name;
+  TmplGTypeFunc symbol = NULL;
+
+  if (base_info == NULL || GI_INFO_TYPE_OBJECT != g_base_info_get_type (base_info))
+    return NULL;
+
+  if (!(typelib = g_base_info_get_typelib (base_info)))
+    return NULL;
+
+  if (!(symbol_name = g_object_info_get_type_init (base_info)))
+    return NULL;
+
+  if (!g_typelib_symbol (typelib, symbol_name, (gpointer *)&symbol))
+    return NULL;
+
+  return symbol;
+}