util: add support for parametrized tests

munit supports test parameters (char* only) but the setup is a big
awkward/impossible in C to define statically. So lets simply pass the
parameters as one NULL-terminated string list and require names to be
prefixed with an @. During the test setup we can split that list up into
multiple parameters and pass those to the munit setup where they're
accessible via another wrapper macro:

MUNIT_TEST_WITH_PARAMS(test_foo, "@x", "1", "2", "@y", "100", "200") {
   const char *x = MUNIT_TEST_PARAM("@x");
   const char *y = MUNIT_TEST_PARAM("@y");
}

Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/365>

src/util-munit.c

@@ -56,10 +56,42 @@ munit_tests_run(int argc, char **argv)
 	_cleanup_free_ MunitTest *tests = calloc(count, sizeof(*tests));
 	size_t idx = 0;
 	foreach_test(t) {
+		size_t nparams = 0;
+		MunitParameterEnum *parameters = calloc(MUNIT_TEST_MAX_PARAMS, sizeof(*parameters));
+
+		const char *name = NULL;
+		char **values = NULL;
+		for (size_t i = 0; t->params[i]; i++) {
+			if (t->params[i][0] == '@') {
+				if (name != NULL) {
+					assert(nparams < MUNIT_TEST_MAX_PARAMS);
+					assert(strv_len(values) > 0);
+					/* Not stripping the @! */
+					parameters[nparams].name = xstrdup(name);
+					parameters[nparams].values = steal(&values);
+					++nparams;
+				}
+				name = t->params[i];
+			} else {
+				assert(i > 0); /* First one must be a name */
+				values = strv_append_strdup(values, t->params[i]);
+			}
+		}
+		if (name != NULL) {
+			assert(nparams < MUNIT_TEST_MAX_PARAMS);
+			assert(strv_len(values) > 0);
+			/* Not stripping the @! */
+			parameters[nparams].name = xstrdup(name);
+			parameters[nparams].values = steal(&values);
+			++nparams;
+		}
+
 		MunitTest test = {
 			.name = xaprintf("%s", t->name),
 			.test = t->func,
+			.parameters = parameters,
 		};
+
 		tests[idx++] = test;
 	}
 
@@ -91,8 +123,10 @@ munit_tests_run(int argc, char **argv)
 
 	int rc = munit_suite_main(&suite, setup.userdata, setup.argc, setup.argv);
 
-	for (idx = 0; idx < count; idx++)
+	for (idx = 0; idx < count; idx++) {
 		free(tests[idx].name);
+		free(tests[idx].parameters);
+	}
 
 	return rc;
 }

src/util-munit.h

@@ -41,6 +41,9 @@
 
 #include <munit.h>
 
+/* Random number, bumb if need be */
+#define MUNIT_TEST_MAX_PARAMS 64
+
 /**
  * Put at the top of the file somewhere, declares the start/stop for the test section we need.
  */
@@ -61,6 +64,7 @@ struct test_function {
 	const char *name;	/* function name */
 	const char *file;	/* file name */
 	munit_test_func_t func;	/* test function */
+	const char *params[MUNIT_TEST_MAX_PARAMS];
 } __attribute__((aligned(16)));
 
 /**
@@ -104,9 +108,34 @@ __attribute__((section("test_functions_section"))) = {				\
 	.name = #_func,								\
 	.func = _func,								\
 	.file = __FILE__,							\
+	.params = { NULL },							\
 };										\
 static MunitResult _func(const MunitParameter params[], void *user_data)
 
+/**
+ * Same as MUNIT test but takes a list of strings that define parameters
+ * and their values. Parameter names must be prefixed with @, for example:
+ * MUNIT_TEST_WITH_PARAMS(test_foo, "@x", "1", "2", "@y", "100", "200") {
+ *    const char *x = MUNIT_TEST_PARAM("@x");
+ *    const char *y = MUNIT_TEST_PARAM("@y");
+ * }
+ */
+#define MUNIT_TEST_WITH_PARAMS(_func, ...) \
+static MunitResult _func(const MunitParameter params[], void *user_data);	\
+static const struct test_function _test_##_func					\
+__attribute__((used))								\
+__attribute__((section("test_functions_section"))) = {				\
+	.name = #_func,								\
+	.func = _func,								\
+	.file = __FILE__,							\
+	.params = { __VA_ARGS__, NULL },					\
+};										\
+static MunitResult _func(const MunitParameter params[], void *user_data)
+
+/* Retrieve the test parameter with the given name */
+#define MUNIT_TEST_PARAM(name_) \
+	munit_parameters_get(params, name_)
+
 /**
  * Defines a struct global_setup_function in a custom ELF section that we can
  * then find in munit_tests_run() to do setup based on argv and/or pass userdata