[hackers] [scc] Fix size of composed types || Roberto E. Vargas Caballero

[git]

commit 5333c3cfde5f199f893cf52c4476f173b672bba0
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Tue Aug 25 22:38:30 2015 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Tue Aug 25 22:38:30 2015 +0200

    Fix size of composed types
    
    Size field of composed types was not initialized,
    so any use of sizeof or addressing arrays was using
    non initialized data.

diff --git a/cc1/types.c b/cc1/types.c
index 2b2156e..c79a8f9 100644
--- a/cc1/types.c
+++ b/cc1/types.c
@@ -261,6 +261,46 @@ invalid_type:
        error("invalid type specification");
 }
 
+/* TODO: define a type for sizes instead of using short */
+static short
+typesize(Type *tp)
+{
+       short align, size;
+       Symbol **sp;
+       int n;
+
+       switch (tp->op) {
+       case ARY:
+               return tp->n.elem * tp->type->size;
+       case PTR:
+               return pvoidtype->size;
+       case STRUCT:
+               size = 0;
+               n = tp->n.elem;
+               for (sp = tp->p.fields; n--; ++sp) {
+                       tp = (*sp)->type;
+                       size += tp->size;
+                       if (n > 0) {
+                               align = tp->align - 1;
+                               size += align - (size & align);
+                       }
+               }
+               return size;
+       case UNION:
+               size = 0;
+               n = tp->n.elem;
+               for (sp = tp->p.fields; n--; ++sp) {
+                       tp = (*sp)->type;
+                       if (tp->size > size)
+                               size = tp->size;
+               }
+               return size;
+       case ENUM:
+               return inttype->size;
+       }
+       return 0;
+}
+
 Type *
 mktype(Type *tp, unsigned op, short nelem, Type *pars[])
 {
@@ -321,6 +361,7 @@ mktype(Type *tp, unsigned op, short nelem, Type *pars[])
                }
        }
 
+       type.size = typesize(&type);
        bp = duptype(&type);
        bp->next = *tbl;
        return *tbl = bp;