ld: teach new tags, and make it reject them also tidy segment constraints

diff --git a/Applications/MWC/cmd/asz80/ld.c b/Applications/MWC/cmd/asz80/ld.c
index 35efc3c..851a163 100644 (file)
--- a/Applications/MWC/cmd/asz80/ld.c
+++ b/Applications/MWC/cmd/asz80/ld.c
@@ -147,6 +147,28 @@ static int is_undefined(const char *name)
        return 1;
 }
 
+static void segment_mismatch(struct symbol *s, uint8_t type2)
+{
+       uint8_t seg1 = s->type & S_SEGMENT;
+       uint8_t seg2 = type2 & S_SEGMENT;
+
+       /* Matching */
+       if (seg1 == seg2)
+               return;
+       /* Existing entry was 'anything'. Co-erce to definition */
+       if (seg1 == S_ANY) {
+               s->type &= ~S_SEGMENT;
+               s->type |= seg2;
+               return;
+       }
+       /* Regardless of the claimed type, an absolute definition fulfills
+          any need. */
+       if (seg2 == ABSOLUTE)
+               return;
+       fprintf(stderr, "Segment mismatch for symbol '%.16s'.\n", s->name);
+       err |= 2;
+}
+
 static struct symbol *find_alloc_symbol(struct object *o, uint8_t type, const char *id, uint16_t value)
 {
        uint8_t hash = hash_symbol(id);
@@ -165,18 +187,15 @@ static struct symbol *find_alloc_symbol(struct object *o, uint8_t type, const ch
                return s;
        }
        /* Already exists. See what is going on */
-       if (type & S_UNKNOWN)
+       if (type & S_UNKNOWN) {
                /* We are an external reference to a symbol. No work needed */
+               segment_mismatch(s, type);
                return s;
+       }
        if (s->type & S_UNKNOWN) {
                /* We are referencing a symbol that was previously unknown but which
                   we define. Fill in the details */
-               if ((s->type & S_SEGMENT) != S_ANY &&
-                       (s->type & S_SEGMENT) != (type & S_SEGMENT)) {
-                       fprintf(stderr, "Segment mismatch for symbol '%s'.\n", id);
-                       err |= 2;
-               }
-               s->type = type;
+               segment_mismatch(s, type);
                s->value = value;
                s->definedby = o;
                return s;
@@ -423,6 +442,10 @@ static void relocate_stream(struct object *o, FILE * op, FILE * ip)
                        fputc(REL_REL, op);
                        continue;
                }
+               if (code == REL_LITTLEENDIAN)
+                       continue;
+               if (code == REL_BIGENDIAN || code == REL_WORDMACHINE)
+                       error("unsupported architecture");
                /* Relocations */
 
                size = ((code & S_SIZE) >> 4) + 1;