+typedef struct check_cfg_env_t {
+ pmap *branch_nodes; /**< map blocks to their branching nodes,
+ map mode_X nodes to the blocks they branch to */
+ int res;
+ ir_nodeset_t reachable_blocks;
+ ir_nodeset_t kept_nodes;
+ ir_nodeset_t true_projs;
+ ir_nodeset_t false_projs;
+} check_cfg_env_t;
+
+static int check_block_cfg(const ir_node *block, check_cfg_env_t *env)
+{
+ pmap *branch_nodes;
+ int n_cfgpreds;
+ int i;
+
+ ASSERT_AND_RET_DBG(ir_nodeset_contains(&env->reachable_blocks, block),
+ "Block is not reachable by blockwalker (endless loop with no kept block?)", 0,
+ ir_printf("block %+F\n", block);
+ );
+
+ n_cfgpreds = get_Block_n_cfgpreds(block);
+ branch_nodes = env->branch_nodes;
+ for (i = 0; i < n_cfgpreds; ++i) {
+ /* check that each mode_X node is only connected
+ * to 1 user */
+ ir_node *branch = get_Block_cfgpred(block, i);
+ ir_node *former_dest;
+ ir_node *former_branch;
+ ir_node *branch_proj;
+ ir_node *branch_block;
+ branch = skip_Tuple(branch);
+ if (is_Bad(branch))
+ continue;
+ former_dest = pmap_get(ir_node, branch_nodes, branch);
+ ASSERT_AND_RET_DBG(former_dest==NULL || is_unknown_jump(skip_Proj(branch)),
+ "Multiple users on mode_X node", 0,
+ ir_printf("node %+F\n", branch);
+ );
+ pmap_insert(branch_nodes, branch, (void*)block);
+
+ /* check that there's only 1 branching instruction in each block */
+ branch_block = get_nodes_block(branch);
+ branch_proj = branch;
+ if (is_Proj(branch)) {
+ branch = skip_Proj(branch);
+ }
+ former_branch = pmap_get(ir_node, branch_nodes, branch_block);
+
+ ASSERT_AND_RET_DBG(former_branch == NULL || former_branch == branch,
+ "Multiple branching nodes in a block", 0,
+ ir_printf("nodes %+F,%+F in block %+F\n",
+ branch, former_branch, branch_block);
+ );
+ pmap_insert(branch_nodes, branch_block, branch);
+
+ if (is_Cond(branch)) {
+ long pn = get_Proj_proj(branch_proj);
+ if (pn == pn_Cond_true)
+ ir_nodeset_insert(&env->true_projs, branch);
+ if (pn == pn_Cond_false)
+ ir_nodeset_insert(&env->false_projs, branch);
+ } else if (is_Switch(branch)) {
+ long pn = get_Proj_proj(branch_proj);
+ if (pn == pn_Switch_default)
+ ir_nodeset_insert(&env->true_projs, branch);
+ }
+ }
+
+ return 1;
+}
+
+static void check_cfg_walk_func(ir_node *node, void *data)
+{
+ check_cfg_env_t *env = (check_cfg_env_t*)data;
+ if (!is_Block(node))
+ return;
+ env->res &= check_block_cfg(node, env);
+}
+
+static int verify_block_branch(const ir_node *block, check_cfg_env_t *env)
+{
+ ir_node *branch = pmap_get(ir_node, env->branch_nodes, block);
+ ASSERT_AND_RET_DBG(branch != NULL
+ || ir_nodeset_contains(&env->kept_nodes, block)
+ || block == get_irg_end_block(get_irn_irg(block)),
+ "block contains no cfop", 0,
+ ir_printf("block %+F\n", block);
+ );
+ return 1;
+}
+
+static int verify_cond_projs(const ir_node *cond, check_cfg_env_t *env)
+{
+ ASSERT_AND_RET_DBG(ir_nodeset_contains(&env->true_projs, cond),
+ "Cond node lacks true proj", 0,
+ ir_printf("Cond %+F\n", cond);
+ );
+ ASSERT_AND_RET_DBG(ir_nodeset_contains(&env->false_projs, cond),
+ "Cond node lacks false proj", 0,
+ ir_printf("Cond %+F\n", cond);
+ );
+ return 1;
+}
+
+static int verify_switch_projs(const ir_node *sw, check_cfg_env_t *env)
+{
+ ASSERT_AND_RET_DBG(ir_nodeset_contains(&env->true_projs, sw),
+ "Switch node lacks default Proj", 0,
+ ir_printf("Switch %+F\n", sw);
+ );
+ return 1;
+}
+
+static void assert_branch(ir_node *node, void *data)
+{
+ check_cfg_env_t *env = (check_cfg_env_t*)data;
+ if (is_Block(node)) {
+ env->res &= verify_block_branch(node, env);
+ } else if (is_Cond(node)) {
+ env->res &= verify_cond_projs(node, env);
+ } else if (is_Switch(node)) {
+ env->res &= verify_switch_projs(node, env);
+ }
+}
+
+static void collect_reachable_blocks(ir_node *block, void *data)
+{
+ ir_nodeset_t *reachable_blocks = (ir_nodeset_t*) data;
+ ir_nodeset_insert(reachable_blocks, block);
+}
+
+/**
+ * Checks CFG well-formedness