[template-glib] eval: make ctor for GI type work

[Christian Hergert <chergert src gnome org>]

commit 0d2c278b3b112e8343e349b1b41756714b87a98a
Author: Christian Hergert <chergert redhat com>
Date:   Wed May 4 18:30:42 2022 -0700

    eval: make ctor for GI type work

 src/meson.build        |  1 +
 src/tmpl-expr-eval.c   | 30 ++++++++++++++++++++++++++++--
 src/tmpl-expr-parser.y | 22 +++++++++++-----------
 tests/test1.script     |  4 ++++
 4 files changed, 44 insertions(+), 13 deletions(-)
---
diff --git a/src/meson.build b/src/meson.build
index 63d27da..bc654e1 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -64,6 +64,7 @@ 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 a363a6f..6188877 100644
--- a/src/tmpl-expr-eval.c
+++ b/src/tmpl-expr-eval.c
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <dlfcn.h>
 #include <girepository.h>
 #include <math.h>
 #include <string.h>
@@ -744,6 +745,7 @@ tmpl_expr_gi_call_eval (TmplExprGiCall  *node,
   GType type;
   guint dispatch_len = 0;
   guint n_args;
+  guint offset = 0;
   guint i;
 
   g_assert (node != NULL);
@@ -906,6 +908,21 @@ tmpl_expr_gi_call_eval (TmplExprGiCall  *node,
       goto apply_args;
     }
 
+  if (G_VALUE_HOLDS (&left, TMPL_TYPE_BASE_INFO) &&
+      (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;
+
+      if ((get_type = dlsym (NULL, type_init)))
+        {
+          type = get_type ();
+          object = NULL;
+          goto lookup_for_object;
+        }
+    }
+
   if (!G_VALUE_HOLDS_OBJECT (&left))
     {
       g_set_error (error,
@@ -929,6 +946,7 @@ tmpl_expr_gi_call_eval (TmplExprGiCall  *node,
 
   type = G_OBJECT_TYPE (object);
 
+lookup_for_object:
   while (g_type_is_a (type, G_TYPE_OBJECT))
     {
       guint n_ifaces;
@@ -985,7 +1003,15 @@ tmpl_expr_gi_call_eval (TmplExprGiCall  *node,
   in_args = g_array_new (FALSE, TRUE, sizeof (GIArgument));
   g_array_set_size (in_args, n_args + 1);
 
-  g_array_index (in_args, GIArgument, 0).v_pointer = object;
+  if (object != NULL)
+    {
+      g_array_index (in_args, GIArgument, 0).v_pointer = object;
+      offset = 1;
+    }
+  else
+    {
+      in_args->len--;
+    }
 
   dispatch_args = (GIArgument *)(gpointer)in_args->data;
   dispatch_len = in_args->len;
@@ -996,7 +1022,7 @@ apply_args:
   for (i = 0; i < n_args; i++)
     {
       g_autoptr(GIArgInfo) arg_info = g_callable_info_get_arg ((GICallableInfo *)function, i);
-      GIArgument *arg = &g_array_index (in_args, GIArgument, i + 1);
+      GIArgument *arg = &g_array_index (in_args, GIArgument, i + offset);
       GValue *value = &g_array_index (values, GValue, i);
       GITypeInfo type_info = { 0 };
 
diff --git a/src/tmpl-expr-parser.y b/src/tmpl-expr-parser.y
index a1d7e16..9a8efd2 100644
--- a/src/tmpl-expr-parser.y
+++ b/src/tmpl-expr-parser.y
@@ -237,6 +237,17 @@ exp: exp CMP exp {
     $$ = tmpl_expr_new_symbol_assign ($1, $3);
     g_free ($1);
   }
+  | BUILTIN '(' explist ')' {
+    $$ = tmpl_expr_new_fn_call ($1, $3);
+  }
+  | NAME '(' explist ')' {
+    $$ = tmpl_expr_new_user_fn_call ($1, $3);
+    g_free ($1);
+  }
+  | NAME '(' ')' {
+    $$ = tmpl_expr_new_user_fn_call ($1, NULL);
+    g_free ($1);
+  }
   | exp '.' NAME '(' ')' {
     $$ = tmpl_expr_new_gi_call ($1, $3, NULL);
     g_free ($3);
@@ -253,17 +264,6 @@ exp: exp CMP exp {
     $$ = tmpl_expr_new_setattr ($1, $3, $5);
     g_free ($3);
   }
-  | BUILTIN '(' explist ')' {
-    $$ = tmpl_expr_new_fn_call ($1, $3);
-  }
-  | NAME '(' explist ')' {
-    $$ = tmpl_expr_new_user_fn_call ($1, $3);
-    g_free ($1);
-  }
-  | NAME '(' ')' {
-    $$ = tmpl_expr_new_user_fn_call ($1, NULL);
-    g_free ($1);
-  }
   | exp '(' ')' {
     $$ = tmpl_expr_new_anon_call ($1, NULL);
   }
diff --git a/tests/test1.script b/tests/test1.script
index fb5809d..0bb0e4f 100644
--- a/tests/test1.script
+++ b/tests/test1.script
@@ -56,4 +56,8 @@ end
 myfunc = func() 9*3
 assert(myfunc() == 27);
 
+# test out construction
+group = Gio.SimpleActionGroup.new()
+assert(group)
+
 1234;