checks: Use source position information for check failures

Now that we retain source position information of nodes and properties,
make that the preferred file name (and position) to print out in check
failures. This will greatly simplify finding and fixing check errors
because most errors are in included source .dtsi files and they get
duplicated every time the source file is included.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -19,6 +19,7 @@
  */
 
 #include "dtc.h"
+#include "srcpos.h"
 
 #ifdef TRACE_CHECKS
 #define TRACE(c, ...) \
@@ -79,13 +80,30 @@ static inline void  PRINTF(5, 6) check_msg(struct check *c, struct dt_info *dti,
 {
 	va_list ap;
 	char *str = NULL;
+	struct srcpos *pos = NULL;
+	char *file_str;
 
 	if (!(c->warn && (quiet < 1)) && !(c->error && (quiet < 2)))
 		return;
 
-	xasprintf(&str, "%s: %s (%s): ",
-		strcmp(dti->outname, "-") ? dti->outname : "<stdout>",
-		(c->error) ? "ERROR" : "Warning", c->name);
+	if (prop && prop->srcpos)
+		pos = prop->srcpos;
+	else if (node && node->srcpos)
+		pos = node->srcpos;
+
+	if (pos) {
+		file_str = srcpos_string(pos);
+		xasprintf(&str, "%s", file_str);
+		free(file_str);
+	} else if (streq(dti->outname, "-")) {
+		xasprintf(&str, "<stdout>");
+	} else {
+		xasprintf(&str, "%s", dti->outname);
+	}
+
+	xasprintf_append(&str, ": %s (%s): ",
+			(c->error) ? "ERROR" : "Warning", c->name);
+
 	if (node) {
 		if (prop)
 			xasprintf_append(&str, "%s:%s: ", node->fullpath, prop->name);
@@ -99,6 +117,17 @@ static inline void  PRINTF(5, 6) check_msg(struct check *c, struct dt_info *dti,
 
 	xasprintf_append(&str, "\n");
 
+	if (!prop && pos) {
+		pos = node->srcpos;
+		while (pos->next) {
+			pos = pos->next;
+
+			file_str = srcpos_string(pos);
+			str += xasprintf_append(&str, "  also defined at %s\n", file_str);
+			free(file_str);
+		}
+	}
+
 	fputs(str, stderr);
 }