selftest: show values when ASSERT_STREQ fails

Rework ASSERT_STREQ so that it prints the actual and expected values
to stderr when it fails (by moving it to a helper function).

gcc/ChangeLog:
	* selftest.c (selftest::fail_formatted): New function.
	(selftest::assert_streq): New function.
	* selftest.h (selftests::fail_formatted): New decl.
	(selftest::assert_streq): New decl.
	(ASSERT_STREQ): Reimplement in terms of selftest::assert_streq.

From-SVN: r237404

gcc/ChangeLog

+2016-06-13  David Malcolm  <dmalcolm@redhat.com>
+
+	* selftest.c (selftest::fail_formatted): New function.
+	(selftest::assert_streq): New function.
+	* selftest.h (selftests::fail_formatted): New decl.
+	(selftest::assert_streq): New decl.
+	(ASSERT_STREQ): Reimplement in terms of selftest::assert_streq.
+
 2016-06-13  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/71403

gcc/selftest.c

@@ -44,4 +44,36 @@ selftest::fail (const char *file, int line, const char *msg)
   abort ();
 }
 
+/* As "fail", but using printf-style formatted output.  */
+
+void
+selftest::fail_formatted (const char *file, int line, const char *fmt, ...)
+{
+  va_list ap;
+
+  fprintf (stderr, "%s:%i: FAIL: ", file, line);
+  /* TODO: add calling function name as well?  */
+  va_start (ap, fmt);
+  vfprintf (stderr, fmt, ap);
+  va_end (ap);
+  fprintf (stderr, "\n");
+  abort ();
+}
+
+/* Implementation detail of ASSERT_STREQ.  */
+
+void
+selftest::assert_streq (const char *file, int line,
+			const char *desc_expected, const char *desc_actual,
+			const char *val_expected, const char *val_actual)
+{
+  if (0 == strcmp (val_expected, val_actual))
+    ::selftest::pass (file, line, "ASSERT_STREQ");
+  else
+    ::selftest::fail_formatted
+	(file, line, "ASSERT_STREQ (%s, %s) expected=\"%s\" actual=\"%s\"",
+	 desc_expected, desc_actual, val_expected, val_actual);
+}
+
+
 #endif /* #if CHECKING_P */

gcc/selftest.h

@@ -39,6 +39,17 @@ extern void pass (const char *file, int line, const char *msg);
 
 extern void fail (const char *file, int line, const char *msg);
 
+/* As "fail", but using printf-style formatted output.  */
+
+extern void fail_formatted (const char *file, int line, const char *fmt, ...)
+ ATTRIBUTE_PRINTF_3;
+
+/* Implementation detail of ASSERT_STREQ.  */
+
+extern void assert_streq (const char *file, int line,
+			  const char *desc_expected, const char *desc_actual,
+			  const char *val_expected, const char *val_actual);
+
 /* Declarations for specific families of tests (by source file), in
    alphabetical order.  */
 extern void bitmap_c_tests ();
@@ -123,15 +134,10 @@ extern int num_passes;
    ::selftest::pass if they are equal,
    ::selftest::fail if they are non-equal.  */
 
-#define ASSERT_STREQ(EXPECTED, ACTUAL)			       \
-  SELFTEST_BEGIN_STMT					       \
-  const char *desc = "ASSERT_STREQ (" #EXPECTED ", " #ACTUAL ")"; \
-  const char *expected_ = (EXPECTED);				  \
-  const char *actual_ = (ACTUAL);				  \
-  if (0 == strcmp (expected_, actual_))				  \
-    ::selftest::pass (__FILE__, __LINE__, desc);			       \
-  else							       \
-    ::selftest::fail (__FILE__, __LINE__, desc);			       \
+#define ASSERT_STREQ(EXPECTED, ACTUAL)				    \
+  SELFTEST_BEGIN_STMT						    \
+  ::selftest::assert_streq (__FILE__, __LINE__, #EXPECTED, #ACTUAL, \
+			    (EXPECTED), (ACTUAL));		    \
   SELFTEST_END_STMT
 
 /* Evaluate PRED1 (VAL1), calling ::selftest::pass if it is true,