Add --fatal-meson-warnings command line option

This makes any warning message printed by meson raise an exception,
intended to be used by CI and developpers to easily catch deprecation
warnings and other potential issues.

3 files changed, 18 insertions, 3 deletions

diff --git a/docs/markdown/snippets/fatal_warnings.md b/docs/markdown/snippets/fatal_warnings.md
new file mode 100644
index 0000000..adf3334
--- /dev/null
+++ b/docs/markdown/snippets/fatal_warnings.md
@@ -0,0 +1,6 @@
+## Fatal warnings
+
+A new command line option has been added: `--fatal-meson-warnings`. When enabled, any
+warning message printed by Meson will be fatal and raise an exception. It is
+intended to be used by developers and CIs to easily catch deprecation warnings,
+or any other potential issues.
diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index 7dddb58..b150731 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -41,6 +41,8 @@ def create_parser():
                    help='Special wrap mode to use')
     p.add_argument('--profile-self', action='store_true', dest='profile',
                    help=argparse.SUPPRESS)
+    p.add_argument('--fatal-meson-warnings', action='store_true', dest='fatal_warnings',
+                   help='Make all Meson warnings fatal')
     p.add_argument('builddir', nargs='?', default=None)
     p.add_argument('sourcedir', nargs='?', default=None)
     return p
@@ -110,7 +112,7 @@ class MesonApp:
 
     def generate(self):
         env = environment.Environment(self.source_dir, self.build_dir, self.options)
-        mlog.initialize(env.get_log_dir())
+        mlog.initialize(env.get_log_dir(), self.options.fatal_warnings)
         if self.options.profile:
             mlog.set_timestamp_start(time.monotonic())
         with mesonlib.BuildDirLock(self.build_dir):
diff --git a/mesonbuild/mlog.py b/mesonbuild/mlog.py
index b8d3ccc..095b8fd 100644
--- a/mesonbuild/mlog.py
+++ b/mesonbuild/mlog.py
@@ -46,11 +46,13 @@ log_file = None
 log_fname = 'meson-log.txt'
 log_depth = 0
 log_timestamp_start = None
+log_fatal_warnings = False
 
-def initialize(logdir):
-    global log_dir, log_file
+def initialize(logdir, fatal_warnings=False):
+    global log_dir, log_file, log_fatal_warnings
     log_dir = logdir
     log_file = open(os.path.join(logdir, log_fname), 'w', encoding='utf8')
+    log_fatal_warnings = fatal_warnings
 
 def set_timestamp_start(start):
     global log_timestamp_start
@@ -145,6 +147,7 @@ def log(*args, **kwargs):
 def _log_error(severity, *args, **kwargs):
     from .mesonlib import get_error_location_string
     from .environment import build_filename
+    from .mesonlib import MesonException
     if severity == 'warning':
         args = (yellow('WARNING:'),) + args
     elif severity == 'error':
@@ -162,6 +165,10 @@ def _log_error(severity, *args, **kwargs):
 
     log(*args, **kwargs)
 
+    global log_fatal_warnings
+    if log_fatal_warnings:
+        raise MesonException("Fatal warnings enabled, aborting")
+
 def error(*args, **kwargs):
     return _log_error('error', *args, **kwargs)