Safer debugging and assertion macros.

Spl's debugging and assertion macros macro used the typical do/while(0)
form for if/else friendliness, however, this limits their use in contexts
where a do loop is not valid; such as within another multi-statement
style macro.

The following macros have been converted to not use do/while(0):
	PANIC, ASSERT, ASSERTF, VERIFY, VERIFY3_IMPL

PANIC has been converted to a wrapper around the new spl_PANIC() function.

The other macros have been converted to use the "&&" operator for the
branch-predicition conditional and also to use spl_PANIC().

The __ASSERT() macro was not touched.  It is only used by the debugging
infrastructure and that code, including this macro, will be retired when
the tracepoint patches are merged.

Signed-off-by: Tim Chase <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #367

1 files changed, 21 insertions, 0 deletions

diff --git a/module/spl/spl-err.c b/module/spl/spl-err.c
index b6d15f019..2706f9bd1 100644
--- a/module/spl/spl-err.c
+++ b/module/spl/spl-err.c
@@ -39,6 +39,27 @@ static char ce_prefix[CE_IGNORE][10] = { "", "NOTICE: ", "WARNING: ", "" };
 static char ce_suffix[CE_IGNORE][2] = { "", "\n", "\n", "" };
 #endif
 
+int
+spl_PANIC(char *filename, const char *functionname,
+    int lineno, const char *fmt, ...) {
+	char msg[MAXMSGLEN];
+	va_list ap;
+
+	va_start(ap, fmt);
+	if (vsnprintf(msg, sizeof (msg), fmt, ap) == sizeof (msg))
+		msg[sizeof (msg) - 1] = '\0';
+	va_end(ap);
+#ifdef NDEBUG
+	printk(KERN_EMERG "%s", msg);
+#else
+	spl_debug_msg(NULL, 0, 0,
+	     filename, functionname, lineno, "%s", msg);
+#endif
+	spl_debug_bug(filename, functionname, lineno, 0);
+	return 1;
+}
+EXPORT_SYMBOL(spl_PANIC);
+
 void
 vpanic(const char *fmt, va_list ap)
 {