[PATCH] Create new and use new print_error that uses printf style formatting.

[John Bonesio <bones-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

yyerror is meant to be called by the parser internal code, and it's interface
is limited. Instead create and call a new error message routine that allows
formatted strings to be used.

yyerror uses the new routine so error formatting remains consistent.

Signed-of-by: John Bonesio <bones-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
---
Here's my second attempt at this. The goal is to provide a way to display better
error mesasges to help the dts writer.

- John

 dtc-parser.y |   26 ++++++++++++++++++--------
 srcpos.c     |   21 +++++++++++++--------
 srcpos.h     |    2 ++
 3 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/dtc-parser.y b/dtc-parser.y
index 0aaf8e8..e1846d4 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -27,6 +27,7 @@
 YYLTYPE yylloc;
 
 extern int yylex(void);
+extern void print_error(char const *fmt, ...);
 extern void yyerror(char const *s);
 
 extern struct boot_info *the_boot_info;
@@ -136,8 +137,8 @@ devicetree:
 			if (target)
 				merge_nodes(target, $3);
 			else
-				yyerror("label does not exist in "
-					" node redefinition");
+				print_error("label, '%s' does not exist in"
+					" node extension", $2);
 			$$ = $1;
 		}
 	;
@@ -295,7 +296,7 @@ subnodes:
 		}
 	| subnode propdef
 		{
-			yyerror("syntax error: properties must precede subnodes");
+			print_error("syntax error: properties must precede subnodes");
 			YYERROR;
 		}
 	;
@@ -314,12 +315,21 @@ subnode:
 
 %%
 
-void yyerror(char const *s)
+void print_error(char const *fmt, ...)
 {
-	srcpos_error(&yylloc, "%s", s);
+	va_list va;
+
+	va_start(va, fmt);
+	srcpos_verror(&yylloc, fmt, va);
+	va_end(va);
+
 	treesource_error = 1;
 }
 
+void yyerror(char const *s) {
+	print_error("%s", s);
+}
+
 static unsigned long long eval_literal(const char *s, int base, int bits)
 {
 	unsigned long long val;
@@ -328,11 +338,11 @@ static unsigned long long eval_literal(const char *s, int base, int bits)
 	errno = 0;
 	val = strtoull(s, &e, base);
 	if (*e)
-		yyerror("bad characters in literal");
+		print_error("bad characters in literal");
 	else if ((errno == ERANGE)
 		 || ((bits < 64) && (val >= (1ULL << bits))))
-		yyerror("literal out of range");
+		print_error("literal out of range");
 	else if (errno != 0)
-		yyerror("bad literal");
+		print_error("bad literal");
 	return val;
 }
diff --git a/srcpos.c b/srcpos.c
index 87d7f17..2dbc874 100644
--- a/srcpos.c
+++ b/srcpos.c
@@ -208,20 +208,25 @@ srcpos_string(struct srcpos *pos)
 	return pos_str;
 }
 
+void
+srcpos_verror(struct srcpos *pos, char const *fmt, va_list va)
+{
+       const char *srcstr;
+
+       srcstr = srcpos_string(pos);
+
+       fprintf(stdout, "Error: %s ", srcstr);
+       vfprintf(stdout, fmt, va);
+       fprintf(stdout, "\n");
+}
 
 void
 srcpos_error(struct srcpos *pos, char const *fmt, ...)
 {
-	const char *srcstr;
 	va_list va;
-	va_start(va, fmt);
-
-	srcstr = srcpos_string(pos);
-
-	fprintf(stderr, "Error: %s ", srcstr);
-	vfprintf(stderr, fmt, va);
-	fprintf(stderr, "\n");
 
+	va_start(va, fmt);
+	srcpos_verror(pos, fmt, va);
 	va_end(va);
 }
 
diff --git a/srcpos.h b/srcpos.h
index 985f847..bd7966e 100644
--- a/srcpos.h
+++ b/srcpos.h
@@ -76,6 +76,8 @@ extern struct srcpos *srcpos_copy(struct srcpos *pos);
 extern char *srcpos_string(struct srcpos *pos);
 extern void srcpos_dump(struct srcpos *pos);
 
+extern void srcpos_verror(struct srcpos *pos, char const *, va_list va)
+     __attribute__((format(printf, 2, 0)));
 extern void srcpos_error(struct srcpos *pos, char const *, ...)
      __attribute__((format(printf, 2, 3)));
 extern void srcpos_warn(struct srcpos *pos, char const *, ...)