/* +----------------------------------------------------------------------+ | Zend Engine, SSA validation | +----------------------------------------------------------------------+ | Copyright (c) The PHP Group | +----------------------------------------------------------------------+ | This source file is subject to version 3.01 of the PHP license, | | that is bundled with this package in the file LICENSE, and is | | available through the world-wide-web at the following url: | | http://www.php.net/license/3_01.txt | | If you did not receive a copy of the PHP license and are unable to | | obtain it through the world-wide-web, please send a note to | | license@php.net so we can mail you a copy immediately. | +----------------------------------------------------------------------+ | Authors: Nikita Popov | +----------------------------------------------------------------------+ */ #include "ZendAccelerator.h" #include "Optimizer/zend_optimizer_internal.h" /* The ssa_verify_integrity() function ensures that that certain invariants of the SSA form and * CFG are upheld and prints messages to stderr if this is not the case. */ static inline zend_bool is_in_use_chain(zend_ssa *ssa, int var, int check) { int use; FOREACH_USE(&ssa->vars[var], use) { if (use == check) { return 1; } } FOREACH_USE_END(); return 0; } static inline zend_bool is_in_phi_use_chain(zend_ssa *ssa, int var, zend_ssa_phi *check) { zend_ssa_phi *phi; FOREACH_PHI_USE(&ssa->vars[var], phi) { if (phi == check) { return 1; } } FOREACH_PHI_USE_END(); return 0; } static inline zend_bool is_used_by_op(zend_ssa *ssa, int op, int check) { zend_ssa_op *ssa_op = &ssa->ops[op]; return (ssa_op->op1_use == check) || (ssa_op->op2_use == check) || (ssa_op->result_use == check); } static inline zend_bool is_defined_by_op(zend_ssa *ssa, int op, int check) { zend_ssa_op *ssa_op = &ssa->ops[op]; return (ssa_op->op1_def == check) || (ssa_op->op2_def == check) || (ssa_op->result_def == check); } static inline zend_bool is_in_phi_sources(zend_ssa *ssa, zend_ssa_phi *phi, int check) { int source; FOREACH_PHI_SOURCE(phi, source) { if (source == check) { return 1; } } FOREACH_PHI_SOURCE_END(); return 0; } static inline zend_bool is_in_predecessors(zend_cfg *cfg, zend_basic_block *block, int check) { int i, *predecessors = &cfg->predecessors[block->predecessor_offset]; for (i = 0; i < block->predecessors_count; i++) { if (predecessors[i] == check) { return 1; } } return 0; } static inline zend_bool is_in_successors(zend_basic_block *block, int check) { int s; for (s = 0; s < block->successors_count; s++) { if (block->successors[s] == check) { return 1; } } return 0; } static inline zend_bool is_var_type(zend_uchar type) { return type == IS_CV || type == IS_VAR || type == IS_TMP_VAR; } #define FAIL(...) do { \ if (status == SUCCESS) { \ fprintf(stderr, "\nIn function %s::%s (%s):\n", \ op_array->scope ? ZSTR_VAL(op_array->scope->name) : "", \ op_array->function_name ? ZSTR_VAL(op_array->function_name) : "{main}", extra); \ } \ fprintf(stderr, __VA_ARGS__); \ status = FAILURE; \ } while (0) #define VARFMT "%d (%s%s)" #define VAR(i) \ (i), (ssa->vars[i].var < op_array->last_var ? "CV $" : "TMP"), \ (ssa->vars[i].var < op_array->last_var ? ZSTR_VAL(op_array->vars[ssa->vars[i].var]) : "") #define INSTRFMT "%d (%s)" #define INSTR(i) \ (i), (zend_get_opcode_name(op_array->opcodes[i].opcode)) int ssa_verify_integrity(zend_op_array *op_array, zend_ssa *ssa, const char *extra) { zend_cfg *cfg = &ssa->cfg; zend_ssa_phi *phi; int i, status = SUCCESS; /* Vars */ for (i = 0; i < ssa->vars_count; i++) { zend_ssa_var *var = &ssa->vars[i]; int use, c; uint32_t type = ssa->var_info[i].type; if (var->definition < 0 && !var->definition_phi && i > op_array->last_var) { if (var->use_chain >= 0) { FAIL("var " VARFMT " without def has op uses\n", VAR(i)); } if (var->phi_use_chain) { FAIL("var " VARFMT " without def has phi uses\n", VAR(i)); } } if (var->definition >= 0 && var->definition_phi) { FAIL("var " VARFMT " has both def and def_phi\n", VAR(i)); } if (var->definition >= 0) { if (!is_defined_by_op(ssa, var->definition, i)) { FAIL("var " VARFMT " not defined by op " INSTRFMT "\n", VAR(i), INSTR(var->definition)); } } if (var->definition_phi) { if (var->definition_phi->ssa_var != i) { FAIL("var " VARFMT " not defined by given phi\n", VAR(i)); } } c = 0; FOREACH_USE(var, use) { if (++c > 10000) { FAIL("cycle in uses of " VARFMT "\n", VAR(i)); return status; } if (!is_used_by_op(ssa, use, i)) { fprintf(stderr, "var " VARFMT " not in uses of op %d\n", VAR(i), use); } } FOREACH_USE_END(); c = 0; FOREACH_PHI_USE(var, phi) { if (++c > 10000) { FAIL("cycle in phi uses of " VARFMT "\n", VAR(i)); return status; } if (!is_in_phi_sources(ssa, phi, i)) { FAIL("var " VARFMT " not in phi sources of %d\n", VAR(i), phi->ssa_var); } } FOREACH_PHI_USE_END(); if ((type & MAY_BE_ARRAY_KEY_ANY) && !(type & MAY_BE_ARRAY_OF_ANY)) { FAIL("var " VARFMT " has array key type but not value type\n", VAR(i)); } if ((type & MAY_BE_ARRAY_OF_ANY) && !(type & MAY_BE_ARRAY_KEY_ANY)) { FAIL("var " VARFMT " has array value type but not key type\n", VAR(i)); } } /* Instructions */ FOREACH_INSTR_NUM(i) { zend_ssa_op *ssa_op = &ssa->ops[i]; zend_op *opline = &op_array->opcodes[i]; if (is_var_type(opline->op1_type)) { if (ssa_op->op1_use < 0 && ssa_op->op1_def < 0) { FAIL("var op1 of " INSTRFMT " does not use/def an ssa var\n", INSTR(i)); } } else { if (ssa_op->op1_use >= 0 || ssa_op->op1_def >= 0) { FAIL("non-var op1 of " INSTRFMT " uses or defs an ssa var\n", INSTR(i)); } } if (is_var_type(opline->op2_type)) { if (ssa_op->op2_use < 0 && ssa_op->op2_def < 0) { FAIL("var op2 of " INSTRFMT " does not use/def an ssa var\n", INSTR(i)); } } else { if (ssa_op->op2_use >= 0 || ssa_op->op2_def >= 0) { FAIL("non-var op2 of " INSTRFMT " uses or defs an ssa var\n", INSTR(i)); } } if (is_var_type(opline->result_type)) { if (ssa_op->result_use < 0 && ssa_op->result_def < 0) { FAIL("var result of " INSTRFMT " does not use/def an ssa var\n", INSTR(i)); } } else { if (ssa_op->result_use >= 0 || ssa_op->result_def >= 0) { FAIL("non-var result of " INSTRFMT " uses or defs an ssa var\n", INSTR(i)); } } if (ssa_op->op1_use >= 0) { if (ssa_op->op1_use >= ssa->vars_count) { FAIL("op1 use %d out of range\n", ssa_op->op1_use); } if (!is_in_use_chain(ssa, ssa_op->op1_use, i)) { FAIL("op1 use of " VARFMT " in " INSTRFMT " not in use chain\n", VAR(ssa_op->op1_use), INSTR(i)); } if (VAR_NUM(opline->op1.var) != ssa->vars[ssa_op->op1_use].var) { FAIL("op1 use of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->op1_use), VAR_NUM(opline->op1.var), INSTR(i)); } } if (ssa_op->op2_use >= 0) { if (ssa_op->op2_use >= ssa->vars_count) { FAIL("op2 use %d out of range\n", ssa_op->op2_use); } if (!is_in_use_chain(ssa, ssa_op->op2_use, i)) { FAIL("op2 use of " VARFMT " in " INSTRFMT " not in use chain\n", VAR(ssa_op->op2_use), INSTR(i)); } if (VAR_NUM(opline->op2.var) != ssa->vars[ssa_op->op2_use].var) { FAIL("op2 use of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->op2_use), VAR_NUM(opline->op2.var), INSTR(i)); } } if (ssa_op->result_use >= 0) { if (ssa_op->result_use >= ssa->vars_count) { FAIL("result use %d out of range\n", ssa_op->result_use); } if (!is_in_use_chain(ssa, ssa_op->result_use, i)) { FAIL("result use of " VARFMT " in " INSTRFMT " not in use chain\n", VAR(ssa_op->result_use), INSTR(i)); } if (VAR_NUM(opline->result.var) != ssa->vars[ssa_op->result_use].var) { FAIL("result use of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->result_use), VAR_NUM(opline->result.var), INSTR(i)); } } if (ssa_op->op1_def >= 0) { if (ssa_op->op1_def >= ssa->vars_count) { FAIL("op1 def %d out of range\n", ssa_op->op1_def); } if (ssa->vars[ssa_op->op1_def].definition != i) { FAIL("op1 def of " VARFMT " in " INSTRFMT " invalid\n", VAR(ssa_op->op1_def), INSTR(i)); } if (VAR_NUM(opline->op1.var) != ssa->vars[ssa_op->op1_def].var) { FAIL("op1 def of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->op1_def), VAR_NUM(opline->op1.var), INSTR(i)); } } if (ssa_op->op2_def >= 0) { if (ssa_op->op2_def >= ssa->vars_count) { FAIL("op2 def %d out of range\n", ssa_op->op2_def); } if (ssa->vars[ssa_op->op2_def].definition != i) { FAIL("op2 def of " VARFMT " in " INSTRFMT " invalid\n", VAR(ssa_op->op2_def), INSTR(i)); } if (VAR_NUM(opline->op2.var) != ssa->vars[ssa_op->op2_def].var) { FAIL("op2 def of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->op2_def), VAR_NUM(opline->op2.var), INSTR(i)); } } if (ssa_op->result_def >= 0) { if (ssa_op->result_def >= ssa->vars_count) { FAIL("result def %d out of range\n", ssa_op->result_def); } if (ssa->vars[ssa_op->result_def].definition != i) { FAIL("result def of " VARFMT " in " INSTRFMT " invalid\n", VAR(ssa_op->result_def), INSTR(i)); } if (VAR_NUM(opline->result.var) != ssa->vars[ssa_op->result_def].var) { FAIL("result def of " VARFMT " does not match op %d of " INSTRFMT "\n", VAR(ssa_op->result_def), VAR_NUM(opline->result.var), INSTR(i)); } } } FOREACH_INSTR_NUM_END(); /* Phis */ FOREACH_PHI(phi) { unsigned num_sources = NUM_PHI_SOURCES(phi); for (i = 0; i < num_sources; i++) { int source = phi->sources[i]; if (source < 0) { FAIL(VARFMT " negative source\n", VAR(phi->ssa_var)); } if (!is_in_phi_use_chain(ssa, source, phi)) { FAIL(VARFMT " not in phi use chain of %d\n", VAR(phi->ssa_var), source); } if (ssa->vars[source].var != ssa->vars[phi->ssa_var].var) { FAIL(VARFMT " source of phi for " VARFMT "\n", VAR(source), VAR(phi->ssa_var)); } if (phi->use_chains[i]) { int j; for (j = i + 1; j < num_sources; j++) { if (phi->sources[j] == source && phi->use_chains[j]) { FAIL("use chain for source " VARFMT " of phi " VARFMT " at %d despite earlier use\n", VAR(source), VAR(phi->ssa_var), j); } } } } if (ssa->vars[phi->ssa_var].definition_phi != phi) { FAIL(VARFMT " does not define this phi\n", VAR(phi->ssa_var)); } } FOREACH_PHI_END(); /* Blocks */ for (i = 0; i < cfg->blocks_count; i++) { zend_basic_block *block = &cfg->blocks[i]; int *predecessors = &cfg->predecessors[block->predecessor_offset]; int s, j; if (i != 0 && block->start < (block-1)->start + (block-1)->len) { FAIL("Block %d start %d smaller previous end %d\n", i, block->start, (block-1)->start + (block-1)->len); } if (i != cfg->blocks_count-1 && block->start + block->len > (block+1)->start) { FAIL("Block %d end %d greater next start %d\n", i, block->start + block->len, (block+1)->start); } for (j = block->start; j < block->start + block->len; j++) { if (cfg->map[j] != i) { FAIL("Instr " INSTRFMT " not associated with block %d\n", INSTR(j), i); } } if (!(block->flags & ZEND_BB_REACHABLE)) { if (ssa->blocks[i].phis) { FAIL("Unreachable block %d has phis\n", i); } continue; } for (s = 0; s < block->successors_count; s++) { zend_basic_block *next_block; if (block->successors[s] < 0) { FAIL("Successor number %d of %d negative", s, i); } next_block = &cfg->blocks[block->successors[s]]; if (!(next_block->flags & ZEND_BB_REACHABLE)) { FAIL("Successor %d of %d not reachable\n", block->successors[s], i); } if (!is_in_predecessors(cfg, next_block, i)) { FAIL("Block %d predecessors missing %d\n", block->successors[s], i); } } for (j = 0; j < block->predecessors_count; j++) { if (predecessors[j] >= 0) { int k; zend_basic_block *prev_block = &cfg->blocks[predecessors[j]]; if (!(prev_block->flags & ZEND_BB_REACHABLE)) { FAIL("Predecessor %d of %d not reachable\n", predecessors[j], i); } if (!is_in_successors(prev_block, i)) { FAIL("Block %d successors missing %d\n", predecessors[j], i); } for (k = 0; k < block->predecessors_count; k++) { if (k != j && predecessors[k] == predecessors[j]) { FAIL("Block %d has duplicate predecessor %d\n", i, predecessors[j]); } } } } } return status; }