dumper: Fix missing symbols in LTO case or with overridden symbol visibility settings

In case a user had a combination of -fvisibility=hidden, -Wl,--as-needed, -flto, -O2
in the CFLAGS the linker would sometimes detect that all the referenced gtype functions
weren't actually used and throw them out with their providing libraries.

Instead of hoping that the user's CFLAGS don't mess without our symbol visibility just use
G_MODULE_EXPORT on the two symbols which reference all other gtype and gquark symbols.

This fixes errors such as:

Invalid GType function: 'gtk_accel_group_get_type'
Failed to find symbol 'gtk_accel_group_get_type'

during the g-ir-scanner execution.

Fixes #280

1 files changed, 2 insertions, 2 deletions

diff --git a/giscanner/dumper.py b/giscanner/dumper.py
index 0c10a780..e4b6ea03 100644
--- a/giscanner/dumper.py
+++ b/giscanner/dumper.py
@@ -126,7 +126,7 @@ class DumpCompiler(object):
             if len(self._get_type_functions) > 0:
                 for func in self._get_type_functions:
                     f.write("extern GType " + func + "(void);\n")
-                f.write("GType (*GI_GET_TYPE_FUNCS_[])(void) = {\n")
+                f.write("G_MODULE_EXPORT GType (*GI_GET_TYPE_FUNCS_[])(void) = {\n")
                 first = True
                 for func in self._get_type_functions:
                     if first:
@@ -138,7 +138,7 @@ class DumpCompiler(object):
             if len(self._error_quark_functions) > 0:
                 for func in self._error_quark_functions:
                     f.write("extern GQuark " + func + "(void);\n")
-                f.write("GQuark (*GI_ERROR_QUARK_FUNCS_[])(void) = {\n")
+                f.write("G_MODULE_EXPORT GQuark (*GI_ERROR_QUARK_FUNCS_[])(void) = {\n")
                 first = True
                 for func in self._error_quark_functions:
                     if first: