scc

commit 1a58b74e71aff78c8d6bee79604a8330c745d927
parent 23e5d28bcfafb191be14957906a01453dd911353
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 14 Jun 2016 12:58:39 +0200

[cc1] Deal with redefinitions in the command line

The POSIX standard commands that -D definitions
without replacement parts must be defined with
a replacement string "1". We also warn in the
case of redefining any macro, even when they have the
same replacement string. It is easier and it is
a good practice to define them only once.

Diffstat:
M
cc1/cpp.c
 | 
23
++++++++++++++++-------

1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/cc1/cpp.c b/cc1/cpp.c
@@ -26,15 +26,24 @@ defmacro(char *s)
 {
 	char *p, *q;
 	Symbol *sym;
+	char def[] = "=1";
 
-	if ((p = strchr(s, '=')) != NULL) {
-		*p++='\0';
-		q = xmalloc(strlen(p) + 4);
-		sprintf(q, "-1#%s", p);
-		p = q;
+	if ((p = strchr(s, '=')) == NULL)
+		p = def;
+	*p++='\0';
+	q = xmalloc(strlen(p) + 4);
+	sprintf(q, "-1#%s", p);
+
+	sym = lookup(NS_CPP, s);
+	if (sym->flags & SDECLARED) {
+		warn("'%s' redefined");
+		free(sym->u.s);
+	} else {
+		install(NS_CPP, sym);
+		sym->flags |= SDECLARED|SSTRING;
 	}
-	sym = install(NS_CPP, lookup(NS_CPP, s));
-	sym->u.s = p;
+
+	sym->u.s = q;
 	return sym;
 }