[babl] Fix darwin/clang map

[Øyvind "pippin" Kolås <ok src gnome org>]

commit a04535b0964d2bd40d08e4b3d16ff27b6ee7262c
Author: Alex Samorukov <samm os2 kiev ua>
Date:   Thu Oct 31 08:14:49 2019 +0100

    Fix darwin/clang map

 babl/meson.build    | 17 ++++++++++++++---
 babl/test-clang.map |  1 +
 babl/test-gnu.map   |  6 ++++++
 gen_babl_map.py     |  6 ++++++
 4 files changed, 27 insertions(+), 3 deletions(-)
---
diff --git a/babl/meson.build b/babl/meson.build
index b551c9a8d..16e1c569f 100644
--- a/babl/meson.build
+++ b/babl/meson.build
@@ -4,6 +4,12 @@ subdir('base')
 python = import('python').find_installation()
 
 version_script = 'babl.map'
+version_script_clang = 'babl.map.clang'
+
+babl_gnu_sym_path = join_paths(meson.current_source_dir(), 'test-gnu.map')
+babl_clang_sym_path = join_paths(meson.current_source_dir(), 'test-clang.map')
+
+
 export_symbols = join_paths(meson.source_root(), 'export-symbols')
 version_script_target = custom_target(version_script,
   input : [ export_symbols, ] ,
@@ -24,9 +30,14 @@ babl_c_args = [
 ]
 
 # Linker arguments
-babl_link_args = [
-  '-Wl,--version-script,' + version_script,
-]
+if cc.links('', name: '-Wl,--version-script', args: ['-shared', '-Wl,--version-script=' + babl_gnu_sym_path])
+  babl_link_args = ['-Wl,--version-script,' + version_script]
+elif host_machine.system() == 'darwin' and cc.has_multi_link_arguments('-Wl,-exported_symbols_list', 
babl_clang_sym_path)
+       # Clang on Darwin
+  babl_link_args = ['-Wl,-exported_symbols_list',version_script_clang]
+else
+       error('Linker doesn\'t support --version-script or -exported_symbols_list')
+endif
 if platform_win32
   babl_link_args += '-Wl,--no-undefined'
 endif
diff --git a/babl/test-clang.map b/babl/test-clang.map
new file mode 100644
index 000000000..2ad252630
--- /dev/null
+++ b/babl/test-clang.map
@@ -0,0 +1 @@
+babl_*
diff --git a/babl/test-gnu.map b/babl/test-gnu.map
new file mode 100644
index 000000000..c27b37d66
--- /dev/null
+++ b/babl/test-gnu.map
@@ -0,0 +1,6 @@
+{
+       global:
+               babl_*;
+       local:
+               *;
+};
diff --git a/gen_babl_map.py b/gen_babl_map.py
index 644ea619b..80a2d3ea3 100644
--- a/gen_babl_map.py
+++ b/gen_babl_map.py
@@ -2,6 +2,7 @@ import sys
 
 export_symbols=sys.argv[1]
 version_file=sys.argv[2]
+version_file_clang=sys.argv[2] + ".clang"
 
 with open(export_symbols, 'r') as syms, \
      open(version_file, 'w') as version:
@@ -9,3 +10,8 @@ with open(export_symbols, 'r') as syms, \
      for sym in syms:
         version.write("        {};\n".format(sym.strip()))
      version.write("    local:\n        *;\n};\n")
+
+with open(export_symbols, 'r') as syms, \
+     open(version_file_clang, 'w') as version:
+     for sym in syms:
+        version.write("_{}\n".format(sym.strip()))