[evince/wip/chpe/symbols-visibility: 12/13] build: Use symbol visibility to hide symbols in private libs

[Christian Persch <chpe src gnome org>]

commit b30057993e34cdd83b73b0f410f223b89d29e8c4
Author: Christian Persch <chpe src gnome org>
Date:   Wed Dec 1 16:51:33 2021 +0100

    build: Use symbol visibility to hide symbols in private libs
    
    Use the visibility attribute to hide all symbols from private
    convenience static libraries used in the backends.
    
    This removes lots of accidentally exposed, private functions.

 backend/dvi/mdvi-lib/meson.build | 1 +
 cut-n-paste/unarr/meson.build    | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/backend/dvi/mdvi-lib/meson.build b/backend/dvi/mdvi-lib/meson.build
index 2f4fb57a4..69e03705c 100644
--- a/backend/dvi/mdvi-lib/meson.build
+++ b/backend/dvi/mdvi-lib/meson.build
@@ -29,6 +29,7 @@ libmdvi = static_library(
   'mdvi',
   sources: sources,
   include_directories: top_inc,
+  gnu_symbol_visibility: 'hidden',
 )
 
 libmdvi_dep = declare_dependency(
diff --git a/cut-n-paste/unarr/meson.build b/cut-n-paste/unarr/meson.build
index 1ff05ff05..3f148c573 100644
--- a/cut-n-paste/unarr/meson.build
+++ b/cut-n-paste/unarr/meson.build
@@ -18,7 +18,8 @@ libunarr = static_library(
   'unarr',
   sources: sources,
   dependencies: zlib_dep,
-  c_args: [ '-DHAVE_ZLIB', '-DNDEBUG' ]
+  c_args: [ '-DHAVE_ZLIB', '-DNDEBUG' ],
+  gnu_symbol_visibility: 'hidden',
 )
 
 libunarr_dep = declare_dependency(