tests: Make it clear to clang-tidy that assert_true may not return

The key is to have __attribute__((noreturn)) somewhere that clang-tidy
can see it. In this case, this is the _fail() function, which is
conditionally called from the assert_true() macro.

This will ensure that clang-tidy doesn't complain about NULL values
that we've asserted against in tests.

expat/tests/basic_tests.c

@@ -3163,7 +3163,7 @@ static int XMLCALL
 external_bom_checker(XML_Parser parser, const XML_Char *context,
                      const XML_Char *base, const XML_Char *systemId,
                      const XML_Char *publicId) {
-  const char *text = "";
+  const char *text;
   UNUSED_P(base);
   UNUSED_P(systemId);
   UNUSED_P(publicId);

expat/tests/common.c

@@ -185,7 +185,7 @@ _xml_failure(XML_Parser parser, const char *file, int line) {
            "u, offset %" XML_FMT_INT_MOD "u)\n    reported from %s, line %d\n",
            err, XML_ErrorString(err), XML_GetCurrentLineNumber(parser),
            XML_GetCurrentColumnNumber(parser), file, line);
-  _assert_true(0, file, line, buffer);
+  _fail(file, line, buffer);
 }
 
 enum XML_Status
@@ -214,9 +214,9 @@ _expect_failure(const char *text, enum XML_Error errorCode,
                 const char *errorMessage, const char *file, int lineno) {
   if (_XML_Parse_SINGLE_BYTES(g_parser, text, (int)strlen(text), XML_TRUE)
       == XML_STATUS_OK)
-    /* Hackish use of _assert_true() macro, but let's us report
+    /* Hackish use of _fail() macro, but lets us report
        the right filename and line number. */
-    _assert_true(0, file, lineno, errorMessage);
+    _fail(file, lineno, errorMessage);
   if (XML_GetErrorCode(g_parser) != errorCode)
     _xml_failure(g_parser, file, lineno);
 }

expat/tests/handlers.c

@@ -1717,7 +1717,9 @@ record_element_end_handler(void *userData, const XML_Char *name) {
 const struct handler_record_entry *
 _handler_record_get(const struct handler_record_list *storage, int index,
                     const char *file, int line) {
-  _assert_true(storage->count > index, file, line, "too few handler calls");
+  if (storage->count <= index) {
+    _fail(file, line, "too few handler calls");
+  }
   return &storage->entries[index];
 }
 

expat/tests/minicheck.c

@@ -244,14 +244,11 @@ srunner_summarize(SRunner *runner, int verbosity) {
 }
 
 void
-_assert_true(int condition, const char *file, int line, const char *msg) {
+_fail(const char *file, int line, const char *msg) {
   /* Always print the error message so it isn't lost.  In this case,
      we have a failure, so there's no reason to be quiet about what
      it is.
   */
-  if (condition) {
-    return;
-  }
   _check_current_filename = file;
   _check_current_lineno = line;
   if (msg != NULL) {

expat/tests/minicheck.h

@@ -83,9 +83,13 @@ extern "C" {
 
 void PRINTF_LIKE(1, 2) set_subtest(char const *fmt, ...);
 
-#  define fail(msg) _assert_true(0, __FILE__, __LINE__, msg)
+#  define fail(msg) _fail(__FILE__, __LINE__, msg)
 #  define assert_true(cond)                                                    \
-    _assert_true((cond), __FILE__, __LINE__, "check failed: " #cond)
+    do {                                                                       \
+      if (! (cond)) {                                                          \
+        _fail(__FILE__, __LINE__, "check failed: " #cond);                     \
+      }                                                                        \
+    } while (0)
 
 typedef void (*tcase_setup_function)(void);
 typedef void (*tcase_teardown_function)(void);
@@ -124,7 +128,11 @@ void _check_set_test_info(char const *function, char const *filename,
  * Prototypes for the actual implementation.
  */
 
-void _assert_true(int condition, const char *file, int line, const char *msg);
+#  if defined(__GNUC__)
+__attribute__((noreturn))
+#  endif
+void
+_fail(const char *file, int line, const char *msg);
 Suite *suite_create(const char *name);
 TCase *tcase_create(const char *name);
 void suite_add_tcase(Suite *suite, TCase *tc);