test: add the pwtest test framework

Heavily inspired by libinput's litest framework (built around check), this is
a from-scratch framework that simplifies adding tests for various parts of
pipewire. See the pwtest.h documentation for details but the basics are:

- PW_TEST() and PWTEST_SUITE() specify the tests to be run
- Test are run in forked processes, any errors/signals are caught and printed
  to the log
- Tests have a custom pipewire daemon started on demand to talk to [1]. The
  daemon's log is available in the test output.
- Output is YAML to be processed into whatever format needed

[1] There are limits here, since we can't emulate devices yet there is only
so much we can rely on with the daemon.

test/pwtest-implementation.h

@@ -0,0 +1,107 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef PWTEST_IMPLEMENTATION_H
+#define PWTEST_IMPLEMENTATION_H
+
+#include <math.h>
+
+/* This header should never be included on its own, it merely exists to make
+ * the user-visible pwtest.h header more readable */
+
+void
+_pwtest_fail_condition(int exitstatus, const char *file, int line, const char *func,
+		      const char *condition, const char *message, ...);
+void
+_pwtest_fail_comparison_int(const char *file, int line, const char *func,
+			   const char *operator, int a, int b,
+			   const char *astr, const char *bstr);
+void
+_pwtest_fail_comparison_double(const char *file, int line, const char *func,
+			      const char *operator, double a, double b,
+			      const char *astr, const char *bstr);
+void
+_pwtest_fail_comparison_ptr(const char *file, int line, const char *func,
+			   const char *comparison);
+
+void
+_pwtest_fail_comparison_str(const char *file, int line, const char *func,
+			   const char *comparison, const char *a, const char *b);
+
+void
+_pwtest_fail_comparison_bool(const char *file, int line, const char *func,
+			     const char *operator, bool a, bool b,
+			     const char *astr, const char *bstr);
+
+#define pwtest_comparison_bool_(a_, op_, b_) \
+	do { \
+		bool _a = !!(a_); \
+		bool _b = !!(b_); \
+		if (!(_a op_ _b)) \
+			_pwtest_fail_comparison_bool(__FILE__, __LINE__, __func__,\
+						#op_, _a, _b, #a_, #b_); \
+	} while(0)
+
+#define pwtest_comparison_int_(a_, op_, b_) \
+	do { \
+		__typeof__(a_) _a = a_; \
+		__typeof__(b_) _b = b_; \
+		if (trunc(_a) != _a || trunc(_b) != _b) \
+			pwtest_error_with_msg("pwtest_int_* used for non-integer value\n"); \
+		if (!((_a) op_ (_b))) \
+			_pwtest_fail_comparison_int(__FILE__, __LINE__, __func__,\
+						#op_, _a, _b, #a_, #b_); \
+	} while(0)
+
+#define pwtest_comparison_ptr_(a_, op_, b_) \
+	do { \
+		__typeof__(a_) _a = a_; \
+		__typeof__(b_) _b = b_; \
+		if (!((_a) op_ (_b))) \
+			_pwtest_fail_comparison_ptr(__FILE__, __LINE__, __func__,\
+						#a_ " " #op_ " " #b_); \
+	} while(0)
+
+#define pwtest_comparison_double_(a_, op_, b_) \
+	do { \
+		const double EPSILON = 1.0/256; \
+		__typeof__(a_) _a = a_; \
+		__typeof__(b_) _b = b_; \
+		if (!((_a) op_ (_b)) && fabs((_a) - (_b)) > EPSILON)  \
+			_pwtest_fail_comparison_double(__FILE__, __LINE__, __func__,\
+						#op_, _a, _b, #a_, #b_); \
+	} while(0)
+
+void _pwtest_add(struct pwtest_context *ctx,
+		 struct pwtest_suite *suite,
+		 const char *funcname, const void *func,
+		 ...) SPA_SENTINEL;
+
+struct pwtest_suite_decl {
+	const char *name;
+	enum pwtest_result (*setup)(struct pwtest_context *, struct pwtest_suite *);
+} __attribute__((aligned(16)));
+
+
+#endif /* PWTEST_IMPLEMENTATION_H */