[hackers] [scc] Give a meanful error message when non scalar are used || Roberto E. Vargas Caballero

[git]

commit ebd1bfd80b0716ec72b256c6b65c01e9f8d8e2f1
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Fri Jan 8 10:40:55 2016 +0100
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Fri Jan 8 10:49:29 2016 +0100

    Give a meanful error message when non scalar are used
    
    There are contexts, mainly conditions, where only scalar are required,
    and the code was giving a very confusing message error related to
    comparision, instead of giving this new error (taken from gcc) which
    shows to the use what is the problem.

diff --git a/cc1/cc1.h b/cc1/cc1.h
index a3c32ec..391b995 100644
--- a/cc1/cc1.h
+++ b/cc1/cc1.h
@@ -44,6 +44,7 @@ struct type {
        bool printed : 1;           /* the type already was printed */
        bool integer : 1;           /* this type is INT or enum */
        bool arith : 1;             /* this type is INT, ENUM, FLOAT */
+       bool aggreg : 1;            /* this type is struct or union */
        size_t size;                /* sizeof the type */
        size_t align;               /* align of the type */
        Type *type;                 /* base type */
diff --git a/cc1/expr.c b/cc1/expr.c
index 39e9096..f211e39 100644
--- a/cc1/expr.c
+++ b/cc1/expr.c
@@ -410,6 +410,10 @@ static Node *
 exp2cond(Node *np, char neg)
 {
        np = decay(np);
+       if (np->type->aggreg) {
+               errorp("used struct/union type value where scalar is required");
+               np = constnode(zero);
+       }
        if (isnodecmp(np->op))
                return (neg) ? negate(np) : np;
        return compare((neg) ?  OEQ : ONE, np, constnode(zero));
diff --git a/cc1/types.c b/cc1/types.c
index 491a5fd..5fda300 100644
--- a/cc1/types.c
+++ b/cc1/types.c
@@ -465,9 +465,10 @@ mktype(Type *tp, int op, TINT nelem, Type *pars[])
                type.printed = 1;
                type.integer = 1;
                type.arith = 1;
-               /* PASSTROUGH */
+               goto no_defined;
        case STRUCT:
        case UNION:
+               type.aggreg = 1;
        no_defined:
                type.defined = 0;
                break;