main: rework preprocessor invocation

[cparser] / diagnostic.c

diff --git a/diagnostic.c b/diagnostic.c
index 6bb53e9..0ca3df1 100644 (file)
--- a/diagnostic.c
+++ b/diagnostic.c
@@ -243,10 +243,16 @@ void diagnosticf(const char *const fmt, ...)
 static void diagnosticposvf(source_position_t const *const pos, char const *const kind, char const *const fmt, va_list ap)
 {
        FILE *const out = stderr;
-       fprintf(out, "%s:%u:", pos->input_name, pos->lineno);
-       if (show_column)
-               fprintf(out, "%u:", (unsigned)pos->colno);
-       fprintf(out, " %s: ", kind);
+       if (pos) {
+               fprintf(out, "%s:", pos->input_name);
+               if (pos->lineno != 0) {
+                       fprintf(out, "%u:", pos->lineno);
+                       if (show_column)
+                               fprintf(out, "%u:", (unsigned)pos->colno);
+               }
+               fputc(' ', out);
+       }
+       fprintf(out, "%s: ", kind);
        curr_pos = pos;
        diagnosticvf(fmt, ap);
 }