---
evaluate.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 59 insertions(+), 0 deletions(-)
diff --git a/evaluate.c b/evaluate.c
index f8343c2..af0be59 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -853,8 +853,67 @@ static struct symbol *evaluate_conditional(struct expression *expr, int iterator
return ctype;
}
+static int are_equivalent_expr(struct expression *lhs, struct expression *rhs)
+{
+ /* recursively determine if lhs ~ rhs. */
+ if (!lhs ^ !rhs) return 0;
+
+ if (lhs->type != rhs->type) return 0;
+ if (lhs->flags != rhs->flags) return 0;
+ if (lhs->op != rhs->op) return 0;
+ if (lhs->ctype != rhs->ctype) return 0;
+
+ switch( lhs->type ) {
+ case EXPR_VALUE:
+ if (lhs->value != rhs->value) return 0;
+ if (lhs->taint != rhs->taint) return 0;
+ break;
+ case EXPR_FVALUE:
+ if (lhs->fvalue != rhs->fvalue) return 0;
+ break;
+ case EXPR_STRING:
+ if (lhs->wide != rhs->wide) return 0;
+ if (lhs->string->length != rhs->string->length) return 0;
+ if (memcmp(lhs->string->data, rhs->string->data,
+ lhs->string->length)) return 0;
+ break;
+/* case EXPR_UNOP: */ /* this is mentioned in the union, but doesn't
+ actually exist */
+ case EXPR_PREOP:
+ case EXPR_POSTOP:
+ if (!are_equivalent_expr(lhs->unop, rhs->unop)) return 0;
+ if (lhs->op_value != rhs->op_value) return 0;
+ break;
+ case EXPR_SYMBOL:
+ case EXPR_TYPE:
+ if (lhs->symbol != rhs->symbol) return 0;
+ break;
+ case EXPR_BINOP:
+ case EXPR_COMMA:
+ case EXPR_COMPARE:
+ case EXPR_LOGICAL:
+ case EXPR_ASSIGNMENT:
+ if (!are_equivalent_expr(lhs->left, rhs->left)) return 0;
+ if (!are_equivalent_expr(lhs->right, rhs->right)) return 0;
+ break;
+
+ /* blah, more... */
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
static struct symbol *evaluate_logical(struct expression *expr)
{
+ if (expr->op == SPECIAL_LOGICAL_AND &&
+ are_equivalent_expr(expr->left, expr->right)) {
+ warning(expr->pos, "identical expressions on both "
+ "sides of '&&'");
+ }
+
if (!evaluate_conditional(expr->left, 0))
return NULL;
if (!evaluate_conditional(expr->right, 0))
--
1.7.4.1
--
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