Vala: enable colored warning and error output (#2142)

mesonbuild/backend/ninjabackend.py

@@ -1094,6 +1094,7 @@ int dummy;
             valac_outputs.append(vala_c_file)
 
         args = self.generate_basic_compiler_args(target, valac)
+        args += valac.get_colorout_args(self.environment.coredata.base_options.get('b_colorout').value)
         # Tell Valac to output everything in our private directory. Sadly this
         # means it will also preserve the directory components of Vala sources
         # found inside the build tree (generated sources).

mesonbuild/compilers/vala.py

@@ -15,7 +15,7 @@
 import os.path
 
 from .. import mlog
-from ..mesonlib import EnvironmentException
+from ..mesonlib import EnvironmentException, version_compare
 
 from .compilers import Compiler
 
@@ -26,6 +26,7 @@ class ValaCompiler(Compiler):
         self.version = version
         self.id = 'valac'
         self.is_cross = False
+        self.base_options = ['b_colorout']
 
     def name_string(self):
         return ' '.join(self.exelist)
@@ -54,6 +55,11 @@ class ValaCompiler(Compiler):
     def get_werror_args(self):
         return ['--fatal-warnings']
 
+    def get_colorout_args(self, colortype):
+        if version_compare(self.version, '>=0.37.1'):
+            return ['--color=' + colortype]
+        return []
+
     def sanity_check(self, work_dir, environment):
         code = 'class MesonSanityCheck : Object { }'
         args = self.get_cross_extra_flags(environment, link=False)