[evince/wip/chpe/symbols-visibility: 15/16] build: Use symbol visibility to hide symbols in private libs

[Christian Persch <chpe src gnome org>]

commit 0906c81c4e16f69c0b6ece4afe3b1e93f2035243
Author: Christian Persch <chpe src gnome org>
Date:   Sat Nov 20 22:40:56 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(