Improve consistency of the symbol visibility
To avoid a symbols file on Windows, Epoxy annotates all the publicly
visible symbols directly in the source, but uses the default symbol
visibility everywhere else. This means that only some symbols are
annotated as `EPOXY_IMPORTEXPORT`, and generally only on Windows.
Additionally, Epoxy has a private 'PUBLIC' pre-processor macro for
internal use, which duplicates the `EPOXY_IMPORTEXPORT` but contains
more logic to detect GCC, in case we're building with GCC on Windows.
This would be enough, except that EGL is also available on Windows,
which means we'd have to annotate the exported `epoxy_*` API inside
epoxy/egl.h as well. At that point, though, we should probably avoid
any confusion, and adopt a single symbol visibility policy across the
board.
This requires some surgery of the generated and common dispatch sources,
but cuts down the overall complexity:
- there is only one annotation, `EPOXY_PUBLIC`, used everywhere
- the annotation detection is done at Epoxy configuration time
- only annotated symbols are public, on every platform
- annotated symbols are immediately visible from the header
diff --git a/include/epoxy/common.h b/include/epoxy/common.h
index 04ff63f..a745f16 100644
--- a/include/epoxy/common.h
+++ b/include/epoxy/common.h
@@ -37,4 +37,8 @@
# define EPOXY_END_DECLS
#endif
+#ifndef EPOXY_PUBLIC
+# define EPOXY_PUBLIC extern
+#endif
+
#endif /* EPOXY_COMMON_H */