map SAL_DLLPUBLIC_RTTI to visibility:default for gcc

Because I want to make more symbols private, but that runs into a
problem with the special symbol "typeinfo for Foo" which is required for
dynamic_cast.

For clang, we can use SAL_DLLPUBLIC_RTTI to make just that magic
"typeinfo for Foo" symbol visible.

But for gcc, we are left with no option but to make the whole class
visible via <MODULE>_DLLPUBLIC.
(I have a feature request logged against gcc to support something like
that at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113958)

But I also don't want to use <MODULE>_DLLPUBLIC, since that blocks
progress of reducing symbol visibility for platforms other than gcc.

So map SAL_DLLPUBLIC_RTTI to visiblity:default for gcc, which means that
only gcc suffers the negative affects of not having that annotation.

However, that runs into the problem that gcc does not like
visibility:default in a couple of places, so I have to introduce some
extra preprocessor stuff.

Change-Id: Ib4fc5c1d2a1f8cf87d5159a4b5684137ec061605
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/164356
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

4 files changed, 14 insertions, 4 deletions

diff --git a/include/rtl/alloc.h b/include/rtl/alloc.h
index 4ce01cf1bcb4..1dc9cefacb0d 100644
--- a/include/rtl/alloc.h
+++ b/include/rtl/alloc.h
@@ -153,7 +153,8 @@ SAL_DLLPUBLIC void SAL_CALL rtl_freeAlignedMemory (
 
 /** Opaque rtl_arena_type.
  */
-typedef struct SAL_DLLPUBLIC_RTTI rtl_arena_st rtl_arena_type;
+struct SAL_DLLPUBLIC_RTTI rtl_arena_st;
+typedef struct rtl_arena_st rtl_arena_type;
 
 #define RTL_ARENA_NAME_LENGTH 31
 
diff --git a/include/rtl/ustring.h b/include/rtl/ustring.h
index 303aff446023..ddc87e29205d 100644
--- a/include/rtl/ustring.h
+++ b/include/rtl/ustring.h
@@ -1197,7 +1197,8 @@ SAL_DLLPUBLIC double SAL_CALL rtl_ustr_toDouble(
 /** @cond INTERNAL */
 /** The implementation of a Unicode string.
 */
-typedef struct SAL_DLLPUBLIC_RTTI _rtl_uString
+struct SAL_DLLPUBLIC_RTTI _rtl_uString;
+typedef struct _rtl_uString
 {
     oslInterlockedCount refCount; /* opaque */
     sal_Int32           length;
diff --git a/include/sal/types.h b/include/sal/types.h
index c61956f647d7..a2ef256239e1 100644
--- a/include/sal/types.h
+++ b/include/sal/types.h
@@ -220,7 +220,7 @@ typedef void *                   sal_Handle;
 #       define SAL_DLLPUBLIC_IMPORT  __attribute__ ((visibility("hidden")))
 #       define SAL_DLLPRIVATE        __attribute__ ((visibility("hidden")))
 #       define SAL_DLLPUBLIC_TEMPLATE __attribute__ ((visibility("hidden")))
-#       define SAL_DLLPUBLIC_RTTI
+#       define SAL_DLLPUBLIC_RTTI     __attribute__ ((visibility("default")))
 #     else
 #       define SAL_DLLPUBLIC_EXPORT  __attribute__ ((visibility("default")))
 #       define SAL_JNI_EXPORT        __attribute__ ((visibility("default")))
@@ -234,7 +234,11 @@ typedef void *                   sal_Handle;
 #           define SAL_DLLPUBLIC_RTTI  __attribute__ ((visibility("default")))
 #         endif
 #       else
-#         define SAL_DLLPUBLIC_RTTI
+// GCC does not have currently have equivalent functionality to clang's type_visibility
+// but I have a feature request for that at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113958
+// Until that is implemented, just make the whole class visible, which is what I would need to
+// do anyhow if something wants to import the typeinfo symbol.
+#         define SAL_DLLPUBLIC_RTTI  __attribute__ ((visibility("default")))
 #       endif
 #     endif
 #   else
diff --git a/include/xmloff/xmlimppr.hxx b/include/xmloff/xmlimppr.hxx
index adfba4eadc60..1f537a322eea 100644
--- a/include/xmloff/xmlimppr.hxx
+++ b/include/xmloff/xmlimppr.hxx
@@ -39,7 +39,11 @@ namespace com::sun::star::uno { template <typename > class Reference; }
 namespace com::sun::star::uno { template <typename > class Sequence; }
 namespace com::sun::star::xml::sax { class XAttributeList; }
 namespace com::sun::star::xml::sax { class XFastAttributeList; }
+#if defined __GNUC__ // gcc does not like visibility annotation on enum
+namespace com::sun::star::drawing { enum class FillStyle; }
+#else
 namespace com::sun::star::drawing { enum class SAL_DLLPUBLIC_RTTI FillStyle; }
+#endif
 
 struct XMLPropertyState;
 class XMLPropertySetMapper;