+location const empty_location = EMPTY_LOCATION_INIT;
+
+/* If BUF is null, add BUFSIZE (which in this case must be less than
+ INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
+ COLUMN. If an overflow occurs, or might occur but is undetectable,
+ return INT_MAX. Assume COLUMN is nonnegative. */
+
+static inline int
+add_column_width (int column, char const *buf, size_t bufsize)
+{
+ size_t width;
+ unsigned int remaining_columns = INT_MAX - column;
+
+ if (buf)
+ {
+ if (INT_MAX / 2 <= bufsize)
+ return INT_MAX;
+ width = mbsnwidth (buf, bufsize, 0);
+ }
+ else
+ width = bufsize;
+
+ return width <= remaining_columns ? column + width : INT_MAX;
+}
+
+/* Set *LOC and adjust scanner cursor to account for token TOKEN of
+ size SIZE. */
+
+void
+location_compute (location *loc, boundary *cur, char const *token, size_t size)
+{
+ int line = cur->line;
+ int column = cur->column;
+ char const *p0 = token;
+ char const *p = token;
+ char const *lim = token + size;
+
+ loc->start = *cur;
+
+ for (p = token; p < lim; p++)
+ switch (*p)
+ {
+ case '\n':
+ line += line < INT_MAX;
+ column = 1;
+ p0 = p + 1;
+ break;
+
+ case '\t':
+ column = add_column_width (column, p0, p - p0);
+ column = add_column_width (column, NULL, 8 - ((column - 1) & 7));
+ p0 = p + 1;
+ break;
+
+ default:
+ break;
+ }
+
+ cur->line = line;
+ cur->column = column = add_column_width (column, p0, p - p0);
+
+ loc->end = *cur;
+
+ if (line == INT_MAX && loc->start.line != INT_MAX)
+ warn_at (*loc, _("line number overflow"));
+ if (column == INT_MAX && loc->start.column != INT_MAX)
+ warn_at (*loc, _("column number overflow"));
+}
+
+
+/* Output to OUT the location LOC.
+ Warning: it uses quotearg's slot 3. */
+unsigned
+location_print (FILE *out, location loc)
+{
+ unsigned res = 0;
+ int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
+ res += fprintf (out, "%s",
+ quotearg_n_style (3, escape_quoting_style, loc.start.file));
+ if (0 <= loc.start.line)
+ {
+ res += fprintf(out, ":%d", loc.start.line);
+ if (0 <= loc.start.column)
+ res += fprintf (out, ".%d", loc.start.column);
+ }
+ if (loc.start.file != loc.end.file)
+ {
+ res += fprintf (out, "-%s",
+ quotearg_n_style (3, escape_quoting_style,
+ loc.end.file));
+ if (0 <= loc.end.line)
+ {
+ res += fprintf(out, ":%d", loc.end.line);
+ if (0 <= end_col)
+ res += fprintf (out, ".%d", end_col);
+ }
+ }
+ else if (0 <= loc.end.line)
+ {
+ if (loc.start.line < loc.end.line)
+ {
+ res += fprintf (out, "-%d", loc.end.line);
+ if (0 <= end_col)
+ res += fprintf (out, ".%d", end_col);
+ }
+ else if (0 <= end_col && loc.start.column < end_col)
+ res += fprintf (out, "-%d", end_col);
+ }
+
+ return res;
+}
+
+void
+boundary_set_from_string (boundary *bound, char *loc_str)
+{
+ /* Must search in reverse since the file name field may
+ * contain `.' or `:'. */
+ char *delim = strrchr (loc_str, '.');
+ aver (delim);
+ *delim = '\0';
+ bound->column = atoi (delim+1);
+ delim = strrchr (loc_str, ':');
+ aver (delim);
+ *delim = '\0';
+ bound->line = atoi (delim+1);
+ bound->file = uniqstr_new (loc_str);
+}