Make dependencies to fontconfig and freetype optional and explicit.

Added meson features for explicitly enabling or disabling the dependencies freetype and fontconfig such that they won't be used even if present on the system.
The meson option use_fontconfig was changed to fontconfig with these possible values:
* 'enabled' (equivalent to old use_fontconfig=true)
* 'auto' (equivalent to old use_fontconfig=false)
* 'disabled' (equivalent to old use_fontconfig=false AND report an error if fontconfig is required on this system).

2 files changed, 22 insertions, 10 deletions

diff --git a/meson.build b/meson.build
index 20f73947..482b0735 100644
--- a/meson.build
+++ b/meson.build
@@ -270,16 +270,24 @@ endif
 pango_deps += harfbuzz_dep
 
 # Only use FontConfig fallback when required or requested
-fontconfig_required = (host_system != 'windows' and host_system != 'darwin') or get_option('use_fontconfig')
 
-fontconfig_dep = dependency('fontconfig', version: fontconfig_req_version, required: false)
+fontconfig_option = get_option('fontconfig')
+
+fontconfig_sys_required = (host_system != 'windows' and host_system != 'darwin')
+if fontconfig_sys_required and fontconfig_option.disabled()
+  error('Fontconfig is required on this platform (pass -Dfontconfig=enabled or -Dfontconfig=auto)')
+endif
+
+fontconfig_required = fontconfig_sys_required or fontconfig_option.enabled()
+
+fontconfig_dep = dependency('fontconfig', version: fontconfig_req_version, required: fontconfig_option)
 if fontconfig_dep.found()
   fontconfig_pc = 'fontconfig'
 else
   if cc.get_id() == 'msvc' and cc.has_header('fontconfig/fontconfig.h')
     # Look for the Visual Studio-style import library if FontConfig's .pc file cannot be
     # found on Visual Studio
-    fontconfig_dep = cc.find_library('fontconfig', required: false)
+    fontconfig_dep = cc.find_library('fontconfig', required: fontconfig_option)
     if fontconfig_dep.found()
       fontconfig_lib = '-lfontconfig'
     endif
@@ -312,7 +320,7 @@ message('fontconfig has FcWeightFromOpenTypeDouble: ' + res)
 
 # The first version of freetype with a pkg-config file is 2.1.5
 # We require both fontconfig and freetype if we are to have either.
-freetype_dep = dependency('freetype2', required: false)
+freetype_dep = dependency('freetype2', required: get_option('freetype'))
 
 if freetype_dep.found()
   freetype2_pc = 'freetype2'
@@ -320,7 +328,7 @@ else
   if cc.get_id() == 'msvc' and cc.has_header('ft2build.h')
     foreach ft2_lib: ['freetype', 'freetypemt']
       if not freetype_dep.found()
-        freetype_dep = cc.find_library(ft2_lib, required: false)
+        freetype_dep = cc.find_library(ft2_lib, required: get_option('freetype'))
         if freetype_dep.found()
           freetype2_lib = '-l@0@'.format(ft2_lib)
         endif
@@ -330,7 +338,7 @@ else
 endif
 
 if fontconfig_required and not freetype_dep.found()
-  freetype_dep = dependency('freetype2', required: false,
+  freetype_dep = dependency('freetype2', required: get_option('freetype'),
                             fallback: ['freetype2', 'freetype_dep'])
 endif
 
diff --git a/meson_options.txt b/meson_options.txt
index 437ba149..5aa7c795 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -10,10 +10,10 @@ option('install-tests',
        description : 'Install tests',
        type: 'boolean',
        value: 'false')
-option('use_fontconfig',
-       description : 'Force using FontConfig where it is optional, on Windows and macOS.  This is ignored on platforms where it is required',
-       type: 'boolean',
-       value: 'false')
+option('fontconfig',
+       description : 'Build with FontConfig support. Passing \'auto\' or \'disabled\' disables fontconfig where it is optional, i.e. on Windows and macOS. Passing \'disabled\' on platforms where fontconfig is required results in error.',
+       type: 'feature',
+       value: 'auto')
 option('sysprof',
        type : 'feature',
        value : 'disabled',
@@ -30,3 +30,7 @@ option('xft',
        type : 'feature',
        value : 'auto',
        description : 'Build with xft support')
+option('freetype',
+       type : 'feature',
+       value : 'auto',
+       description : 'Build with freetype support')