Enhance source position implementation.

Implemented some print and copy routines.
Made empty srcpos objects that will be used later.
Protected .h file from multiple #include's.
Added srcpos_error() and srcpos_warn().

Signed-off-by: Jon Loeliger <jdl@freescale.com>

srcpos.c

@@ -17,18 +17,40 @@
  *                                                                   USA
  */
 
+#define _GNU_SOURCE
+
+#include <stdio.h>
+
 #include "dtc.h"
 #include "srcpos.h"
 
+
 /*
  * Like yylineno, this is the current open file pos.
  */
-
 struct dtc_file *srcpos_file;
 
-static int dtc_open_one(struct dtc_file *file,
-                        const char *search,
-                        const char *fname)
+/*
+ * The empty source position.
+ */
+
+struct dtc_file dtc_empty_file = {
+	.dir = NULL,
+	.name = "<no file>",
+	.file = NULL
+};
+
+srcpos srcpos_empty = {
+	.first_line = 0,
+	.first_column = 0,
+	.last_line = 0,
+	.last_column = 0,
+	.file = &dtc_empty_file
+};
+
+
+static int
+dtc_open_one(struct dtc_file *file, const char *search, const char *fname)
 {
 	char *fullname;
 
@@ -53,8 +75,8 @@ static int dtc_open_one(struct dtc_file *file,
 }
 
 
-struct dtc_file *dtc_open_file(const char *fname,
-                               const struct search_path *search)
+struct dtc_file *
+dtc_open_file(const char *fname, const struct search_path *search)
 {
 	static const struct search_path default_search = { NULL, NULL, NULL };
 
@@ -106,11 +128,113 @@ fail:
 	die("Couldn't open \"%s\": %s\n", fname, strerror(errno));
 }
 
-void dtc_close_file(struct dtc_file *file)
+
+void
+dtc_close_file(struct dtc_file *file)
 {
 	if (fclose(file->file))
 		die("Error closing \"%s\": %s\n", file->name, strerror(errno));
-
-	free(file->dir);
-	free(file);
+}
+
+
+srcpos *
+srcpos_copy(srcpos *pos)
+{
+	srcpos *pos_new;
+
+	pos_new = xmalloc(sizeof(srcpos));
+	memcpy(pos_new, pos, sizeof(srcpos));
+
+	return pos_new;
+}
+
+
+
+void
+srcpos_dump(srcpos *pos)
+{
+	printf("file        : \"%s\"\n",
+	       pos->file ? (char *) pos->file : "<no file>");
+	printf("first_line  : %d\n", pos->first_line);
+	printf("first_column: %d\n", pos->first_column);
+	printf("last_line   : %d\n", pos->last_line);
+	printf("last_column : %d\n", pos->last_column);
+	printf("file        : %s\n", pos->file->name);
+}
+
+
+char *
+srcpos_string(srcpos *pos)
+{
+	const char *fname;
+	char col_buf[100];
+	char *pos_str;
+
+	if (!pos) {
+		fname = "<no-file>";
+	} else if (pos->file->name) {
+		fname = pos->file->name;
+		if (strcmp(fname, "-") == 0)
+			fname = "stdin";
+	} else {
+		fname = "<no-file>";
+	}
+
+	if (pos->first_line == pos->last_line) {
+		if (pos->first_column == pos->last_column) {
+			snprintf(col_buf, sizeof(col_buf),
+				 "%d:%d",
+				 pos->first_line, pos->first_column);
+		} else {
+			snprintf(col_buf, sizeof(col_buf),
+				 "%d:%d-%d",
+				 pos->first_line,
+				 pos->first_column, pos->last_column);
+		}
+
+	} else {
+		snprintf(col_buf, sizeof(col_buf),
+			 "%d:%d - %d:%d",
+			 pos->first_line, pos->first_column,
+			 pos->last_line, pos->last_column);
+	}
+
+	if (asprintf(&pos_str, "%s %s", fname, col_buf) == -1)
+		return "<unknown source position?";
+
+	return pos_str;
+}
+
+
+void
+srcpos_error(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_end(va);
+}
+
+
+void
+srcpos_warn(srcpos *pos, char const *fmt, ...)
+{
+	const char *srcstr;
+	va_list va;
+	va_start(va, fmt);
+
+	srcstr = srcpos_string(pos);
+
+	fprintf(stderr, "Warning: %s ", srcstr);
+	vfprintf(stderr, fmt, va);
+	fprintf(stderr, "\n");
+
+	va_end(va);
 }