Add assertions for DIM_W/RW uses

The result should be used only once and on the directly next opline,
otherwise it may not be safe. Add some assertions to that effect.

diff --git a/ext/opcache/Optimizer/zend_inference.c b/ext/opcache/Optimizer/zend_inference.c
index da40b59e6cf1ed8022dfe1bc0db61e0383b7b184..e11c3cd9c74ba6ff8be14d797134da5e76e4d868 100644 (file)
--- a/ext/opcache/Optimizer/zend_inference.c
+++ b/ext/opcache/Optimizer/zend_inference.c
@@ -3299,6 +3299,7 @@ static int zend_update_type_info(const zend_op_array *op_array,
                                                || opline->opcode == ZEND_FETCH_LIST_W) {
                                        j = ssa_vars[ssa_ops[i].result_def].use_chain;
                                        while (j >= 0) {
+                                               ZEND_ASSERT(j == i + 1 && "Use must be in next opline");
                                                switch (op_array->opcodes[j].opcode) {
                                                        case ZEND_FETCH_DIM_W:
                                                        case ZEND_FETCH_DIM_RW:
@@ -3354,6 +3355,7 @@ static int zend_update_type_info(const zend_op_array *op_array,
                                                        EMPTY_SWITCH_DEFAULT_CASE()
                                                }
                                                j = zend_ssa_next_use(ssa_ops, ssa_ops[i].result_def, j);
+                                               ZEND_ASSERT(j < 0 && "There should only be one use");
                                        }
                                }
                                if ((tmp & MAY_BE_ARRAY) && (tmp & MAY_BE_ARRAY_KEY_ANY)) {