interpreter: add "protocol" kwarg to test

This is the first step towards adding support for TAP.

docs/markdown/Reference-manual.md

@@ -1406,10 +1406,7 @@ executable to run.  The executable can be an [executable build target
 object](#build-target-object) returned by
 [`executable()`](#executable) or an [external program
 object](#external-program-object) returned by
-[`find_program()`](#find_program). The executable's exit code is used
+[`find_program()`](#find_program).
-by the test harness to record the outcome of the test, for example
-exit code zero indicates success. For more on the Meson test harness
-protocol read [Unit Tests](Unit-tests.md).
 
 Keyword arguments are the following:
 
@@ -1446,6 +1443,12 @@ Keyword arguments are the following:
   before test is executed even if they have `build_by_default : false`.
   Since 0.46.0
 
+- `protocol` specifies how the test results are parsed. For now
+  it must be `exitcode`, that is the executable's exit code is used
+  by the test harness to record the outcome of the test. For example
+  an exit code of zero indicates success. For more on the Meson test harness
+  protocol read [Unit Tests](Unit-tests.md). Since 0.50.0
+
 Defined tests can be run in a backend-agnostic way by calling
 `meson test` inside the build dir, or by using backend-specific
 commands, such as `ninja test` or `msbuild RUN_TESTS.vcxproj`.

mesonbuild/backend/backends.py

@@ -84,7 +84,7 @@ class ExecutableSerialisation:
 
 class TestSerialisation:
     def __init__(self, name, project, suite, fname, is_cross_built, exe_wrapper, is_parallel,
-                 cmd_args, env, should_fail, timeout, workdir, extra_paths):
+                 cmd_args, env, should_fail, timeout, workdir, extra_paths, protocol):
         self.name = name
         self.project_name = project
         self.suite = suite
@@ -100,6 +100,7 @@ class TestSerialisation:
         self.timeout = timeout
         self.workdir = workdir
         self.extra_paths = extra_paths
+        self.protocol = protocol
 
 class OptionProxy:
     def __init__(self, name, value):
@@ -756,7 +757,7 @@ class Backend:
                     raise MesonException('Bad object in test command.')
             ts = TestSerialisation(t.get_name(), t.project_name, t.suite, cmd, is_cross,
                                    exe_wrapper, t.is_parallel, cmd_args, t.env,
-                                   t.should_fail, t.timeout, t.workdir, extra_paths)
+                                   t.should_fail, t.timeout, t.workdir, extra_paths, t.protocol)
             arr.append(ts)
         return arr
 

mesonbuild/interpreter.py

@@ -850,7 +850,7 @@ class RunTargetHolder(InterpreterObject, ObjectHolder):
 
 class Test(InterpreterObject):
     def __init__(self, name, project, suite, exe, depends, is_parallel,
-                 cmd_args, env, should_fail, timeout, workdir):
+                 cmd_args, env, should_fail, timeout, workdir, protocol):
         InterpreterObject.__init__(self)
         self.name = name
         self.suite = suite
@@ -863,6 +863,7 @@ class Test(InterpreterObject):
         self.should_fail = should_fail
         self.timeout = timeout
         self.workdir = workdir
+        self.protocol = protocol
 
     def get_exe(self):
         return self.exe
@@ -1973,7 +1974,8 @@ permitted_kwargs = {'add_global_arguments': {'language', 'native'},
                     'library': known_library_kwargs,
                     'subdir': {'if_found'},
                     'subproject': {'version', 'default_options', 'required'},
-                    'test': {'args', 'depends', 'env', 'is_parallel', 'should_fail', 'timeout', 'workdir', 'suite'},
+                    'test': {'args', 'depends', 'env', 'is_parallel', 'should_fail', 'timeout', 'workdir',
+                             'suite', 'protocol'},
                     'vcs_tag': {'input', 'output', 'fallback', 'command', 'replace_string'},
                     }
 
@@ -3269,6 +3271,9 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
             workdir = None
         if not isinstance(timeout, int):
             raise InterpreterException('Timeout must be an integer.')
+        protocol = kwargs.get('protocol', 'exitcode')
+        if protocol not in ('exitcode',):
+            raise InterpreterException('Protocol must be "exitcode".')
         suite = []
         prj = self.subproject if self.is_subproject() else self.build.project_name
         for s in mesonlib.stringlistify(kwargs.get('suite', '')):
@@ -3280,7 +3285,7 @@ This will become a hard error in the future.''' % kwargs['input'], location=self
             if not isinstance(dep, (build.CustomTarget, build.BuildTarget)):
                 raise InterpreterException('Depends items must be build targets.')
         t = Test(args[0], prj, suite, exe.held_object, depends, par, cmd_args,
-                 env, should_fail, timeout, workdir)
+                 env, should_fail, timeout, workdir, protocol)
         if is_base_test:
             self.build.tests.append(t)
             mlog.debug('Adding test', mlog.bold(args[0], True))