gnome: make sure the target build directory is passed first for linking

determine_rpath_dirs() can return paths to external dependencies not
in the build dir and passing them first as a link path leads to
g-ir-scanner for example linking against the already installed library
instead of the just built one.

This was reported in g-i: https://gitlab.gnome.org/GNOME/gobject-introspection/issues/272
and comes up quite often when a library adds some new symbols which aren't present in the
system library, which then makes linking fail.

The first place where the order is changed is _scan_gir_targets(), which looks like an unintentional
change in the refactoring in 8377ea45aa61efbe8e1a75b74

The second place in _get_link_args() has always been that way and only the rpath order is changed,
but it looks to me as if the same rules should apply here too.

4 files changed, 99 insertions, 0 deletions

diff --git a/test cases/frameworks/28 gir link order 2/meson-sample.c b/test cases/frameworks/28 gir link order 2/meson-sample.c
new file mode 100644
index 0000000..d743b2d
--- /dev/null
+++ b/test cases/frameworks/28 gir link order 2/meson-sample.c
@@ -0,0 +1,42 @@
+#include "meson-sample.h"
+
+struct _MesonSample {
+  GObject parent_instance;
+};
+
+G_DEFINE_TYPE (MesonSample, meson_sample, G_TYPE_OBJECT)
+
+/**
+ * meson_sample_new:
+ *
+ * Allocates a new #MesonSample.
+ *
+ * Returns: (transfer full): a #MesonSample.
+ */
+MesonSample *
+meson_sample_new (void)
+{
+  return g_object_new (MESON_TYPE_SAMPLE, NULL);
+}
+
+static void
+meson_sample_class_init (MesonSampleClass *klass)
+{
+}
+
+static void
+meson_sample_init (MesonSample *self)
+{
+}
+
+/**
+ * meson_sample_print_message:
+ * @self: a #MesonSample.
+ *
+ * Prints a message.
+ */
+void
+meson_sample_print_message (MesonSample *self)
+{
+  g_return_if_fail (MESON_IS_SAMPLE (self));
+}
diff --git a/test cases/frameworks/28 gir link order 2/meson-sample.h b/test cases/frameworks/28 gir link order 2/meson-sample.h
new file mode 100644
index 0000000..2c28401
--- /dev/null
+++ b/test cases/frameworks/28 gir link order 2/meson-sample.h
@@ -0,0 +1,17 @@
+#ifndef MESON_SAMPLE_H
+#define MESON_SAMPLE_H
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define MESON_TYPE_SAMPLE (meson_sample_get_type())
+
+G_DECLARE_FINAL_TYPE (MesonSample, meson_sample, MESON, SAMPLE, GObject)
+
+MesonSample *meson_sample_new           (void);
+void         meson_sample_print_message (MesonSample *self);
+
+G_END_DECLS
+
+#endif /* MESON_SAMPLE_H */
diff --git a/test cases/frameworks/28 gir link order 2/meson.build b/test cases/frameworks/28 gir link order 2/meson.build
new file mode 100644
index 0000000..5465a5b
--- /dev/null
+++ b/test cases/frameworks/28 gir link order 2/meson.build
@@ -0,0 +1,35 @@
+project('gir link order 2', 'c')
+
+if not dependency('gobject-2.0', required : false).found()
+  error('MESON_SKIP_TEST gobject not found.')
+endif
+
+gnome = import('gnome')
+gobject = dependency('gobject-2.0')
+
+# This builds a dummy libsample under samelibname that's not really used
+subdir('samelibname')
+
+# This builds the real libsample
+meson_sample_sources = ['meson-sample.c', 'meson-sample.h']
+meson_sample_lib = shared_library(
+  'sample',
+  sources : meson_sample_sources,
+  dependencies : [gobject],
+  link_with: [samelibname],
+  install : false,
+)
+
+# g-ir-scanner should get the linker paths in the right order so it links first
+# against the target libsample and not the dummy one that's just a dependency
+# https://github.com/mesonbuild/meson/pull/5423
+gnome.generate_gir(
+  meson_sample_lib,
+  sources : meson_sample_sources,
+  nsversion : '1.0',
+  namespace : 'Meson',
+  symbol_prefix : 'meson',
+  identifier_prefix : 'Meson',
+  install : false,
+  build_by_default: true,
+)
diff --git a/test cases/frameworks/28 gir link order 2/samelibname/meson.build b/test cases/frameworks/28 gir link order 2/samelibname/meson.build
new file mode 100644
index 0000000..8850372
--- /dev/null
+++ b/test cases/frameworks/28 gir link order 2/samelibname/meson.build
@@ -0,0 +1,5 @@
+samelibname = shared_library(
+  'sample',
+  sources : [],
+  install : false,
+)