zend_ast.c

/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
   +----------------------------------------------------------------------+
   | This source file is subject to version 2.00 of the Zend 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.zend.com/license/2_00.txt.                                |
   | If you did not receive a copy of the Zend license and are unable to  |
   | obtain it through the world-wide-web, please send a note to          |
   | license@zend.com so we can mail you a copy immediately.              |
   +----------------------------------------------------------------------+
   | Authors: Bob Weinand <bwoebi@php.net>                                |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

#include "zend_ast.h"
#include "zend_API.h"
#include "zend_operators.h"
#include "zend_language_parser.h"
#include "zend_smart_str.h"
#include "zend_exceptions.h"
#include "zend_constants.h"
#include "zend_enum.h"

ZEND_API zend_ast_process_t zend_ast_process = NULL;

static inline void *zend_ast_alloc(size_t size) {
	return zend_arena_alloc(&CG(ast_arena), size);
}

static inline void *zend_ast_realloc(void *old, size_t old_size, size_t new_size) {
	void *new = zend_ast_alloc(new_size);
	memcpy(new, old, old_size);
	return new;
}

static inline size_t zend_ast_list_size(uint32_t children) {
	return sizeof(zend_ast_list) - sizeof(zend_ast *) + sizeof(zend_ast *) * children;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_znode(znode *node) {
	zend_ast_znode *ast;

	ast = zend_ast_alloc(sizeof(zend_ast_znode));
	ast->kind = ZEND_AST_ZNODE;
	ast->attr = 0;
	ast->lineno = CG(zend_lineno);
	ast->node = *node;
	return (zend_ast *) ast;
}

static zend_always_inline zend_ast * zend_ast_create_zval_int(zval *zv, uint32_t attr, uint32_t lineno) {
	zend_ast_zval *ast;

	ast = zend_ast_alloc(sizeof(zend_ast_zval));
	ast->kind = ZEND_AST_ZVAL;
	ast->attr = attr;
	ZVAL_COPY_VALUE(&ast->val, zv);
	Z_LINENO(ast->val) = lineno;
	return (zend_ast *) ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_zval_with_lineno(zval *zv, uint32_t lineno) {
	return zend_ast_create_zval_int(zv, 0, lineno);
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_zval_ex(zval *zv, zend_ast_attr attr) {
	return zend_ast_create_zval_int(zv, attr, CG(zend_lineno));
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_zval(zval *zv) {
	return zend_ast_create_zval_int(zv, 0, CG(zend_lineno));
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_zval_from_str(zend_string *str) {
	zval zv;
	ZVAL_STR(&zv, str);
	return zend_ast_create_zval_int(&zv, 0, CG(zend_lineno));
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_zval_from_long(zend_long lval) {
	zval zv;
	ZVAL_LONG(&zv, lval);
	return zend_ast_create_zval_int(&zv, 0, CG(zend_lineno));
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_constant(zend_string *name, zend_ast_attr attr) {
	zend_ast_zval *ast;

	ast = zend_ast_alloc(sizeof(zend_ast_zval));
	ast->kind = ZEND_AST_CONSTANT;
	ast->attr = attr;
	ZVAL_STR(&ast->val, name);
	Z_LINENO(ast->val) = CG(zend_lineno);
	return (zend_ast *) ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_class_const_or_name(zend_ast *class_name, zend_ast *name) {
	zend_string *name_str = zend_ast_get_str(name);
	if (zend_string_equals_literal_ci(name_str, "class")) {
		zend_string_release(name_str);
		return zend_ast_create(ZEND_AST_CLASS_NAME, class_name);
	} else {
		return zend_ast_create(ZEND_AST_CLASS_CONST, class_name, name);
	}
}

ZEND_API zend_ast *zend_ast_create_decl(
	zend_ast_kind kind, uint32_t flags, uint32_t start_lineno, zend_string *doc_comment,
	zend_string *name, zend_ast *child0, zend_ast *child1, zend_ast *child2, zend_ast *child3, zend_ast *child4
) {
	zend_ast_decl *ast;

	ast = zend_ast_alloc(sizeof(zend_ast_decl));
	ast->kind = kind;
	ast->attr = 0;
	ast->start_lineno = start_lineno;
	ast->end_lineno = CG(zend_lineno);
	ast->flags = flags;
	ast->lex_pos = LANG_SCNG(yy_text);
	ast->doc_comment = doc_comment;
	ast->name = name;
	ast->child[0] = child0;
	ast->child[1] = child1;
	ast->child[2] = child2;
	ast->child[3] = child3;
	ast->child[4] = child4;

	return (zend_ast *) ast;
}

#if ZEND_AST_SPEC
ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_0(zend_ast_kind kind) {
	zend_ast *ast;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 0);
	ast = zend_ast_alloc(zend_ast_size(0));
	ast->kind = kind;
	ast->attr = 0;
	ast->lineno = CG(zend_lineno);

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_1(zend_ast_kind kind, zend_ast *child) {
	zend_ast *ast;
	uint32_t lineno;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 1);
	ast = zend_ast_alloc(zend_ast_size(1));
	ast->kind = kind;
	ast->attr = 0;
	ast->child[0] = child;
	if (child) {
		lineno = zend_ast_get_lineno(child);
	} else {
		lineno = CG(zend_lineno);
	}
	ast->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_2(zend_ast_kind kind, zend_ast *child1, zend_ast *child2) {
	zend_ast *ast;
	uint32_t lineno;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 2);
	ast = zend_ast_alloc(zend_ast_size(2));
	ast->kind = kind;
	ast->attr = 0;
	ast->child[0] = child1;
	ast->child[1] = child2;
	if (child1) {
		lineno = zend_ast_get_lineno(child1);
	} else if (child2) {
		lineno = zend_ast_get_lineno(child2);
	} else {
		lineno = CG(zend_lineno);
	}
	ast->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_3(zend_ast_kind kind, zend_ast *child1, zend_ast *child2, zend_ast *child3) {
	zend_ast *ast;
	uint32_t lineno;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 3);
	ast = zend_ast_alloc(zend_ast_size(3));
	ast->kind = kind;
	ast->attr = 0;
	ast->child[0] = child1;
	ast->child[1] = child2;
	ast->child[2] = child3;
	if (child1) {
		lineno = zend_ast_get_lineno(child1);
	} else if (child2) {
		lineno = zend_ast_get_lineno(child2);
	} else if (child3) {
		lineno = zend_ast_get_lineno(child3);
	} else {
		lineno = CG(zend_lineno);
	}
	ast->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_4(zend_ast_kind kind, zend_ast *child1, zend_ast *child2, zend_ast *child3, zend_ast *child4) {
	zend_ast *ast;
	uint32_t lineno;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 4);
	ast = zend_ast_alloc(zend_ast_size(4));
	ast->kind = kind;
	ast->attr = 0;
	ast->child[0] = child1;
	ast->child[1] = child2;
	ast->child[2] = child3;
	ast->child[3] = child4;
	if (child1) {
		lineno = zend_ast_get_lineno(child1);
	} else if (child2) {
		lineno = zend_ast_get_lineno(child2);
	} else if (child3) {
		lineno = zend_ast_get_lineno(child3);
	} else if (child4) {
		lineno = zend_ast_get_lineno(child4);
	} else {
		lineno = CG(zend_lineno);
	}
	ast->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_5(zend_ast_kind kind, zend_ast *child1, zend_ast *child2, zend_ast *child3, zend_ast *child4, zend_ast *child5) {
	zend_ast *ast;
	uint32_t lineno;

	ZEND_ASSERT(kind >> ZEND_AST_NUM_CHILDREN_SHIFT == 5);
	ast = zend_ast_alloc(zend_ast_size(5));
	ast->kind = kind;
	ast->attr = 0;
	ast->child[0] = child1;
	ast->child[1] = child2;
	ast->child[2] = child3;
	ast->child[3] = child4;
	ast->child[4] = child5;
	if (child1) {
		lineno = zend_ast_get_lineno(child1);
	} else if (child2) {
		lineno = zend_ast_get_lineno(child2);
	} else if (child3) {
		lineno = zend_ast_get_lineno(child3);
	} else if (child4) {
		lineno = zend_ast_get_lineno(child4);
	} else if (child5) {
		lineno = zend_ast_get_lineno(child5);
	} else {
		lineno = CG(zend_lineno);
	}
	ast->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_list_0(zend_ast_kind kind) {
	zend_ast *ast;
	zend_ast_list *list;

	ast = zend_ast_alloc(zend_ast_list_size(4));
	list = (zend_ast_list *) ast;
	list->kind = kind;
	list->attr = 0;
	list->lineno = CG(zend_lineno);
	list->children = 0;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_list_1(zend_ast_kind kind, zend_ast *child) {
	zend_ast *ast;
	zend_ast_list *list;
	uint32_t lineno;

	ast = zend_ast_alloc(zend_ast_list_size(4));
	list = (zend_ast_list *) ast;
	list->kind = kind;
	list->attr = 0;
	list->children = 1;
	list->child[0] = child;
	if (child) {
		lineno = zend_ast_get_lineno(child);
		if (lineno > CG(zend_lineno)) {
			lineno = CG(zend_lineno);
		}
	} else {
		lineno = CG(zend_lineno);
	}
	list->lineno = lineno;

	return ast;
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_create_list_2(zend_ast_kind kind, zend_ast *child1, zend_ast *child2) {
	zend_ast *ast;
	zend_ast_list *list;
	uint32_t lineno;

	ast = zend_ast_alloc(zend_ast_list_size(4));
	list = (zend_ast_list *) ast;
	list->kind = kind;
	list->attr = 0;
	list->children = 2;
	list->child[0] = child1;
	list->child[1] = child2;
	if (child1) {
		lineno = zend_ast_get_lineno(child1);
		if (lineno > CG(zend_lineno)) {
			lineno = CG(zend_lineno);
		}
	} else if (child2) {
		lineno = zend_ast_get_lineno(child2);
		if (lineno > CG(zend_lineno)) {
			lineno = CG(zend_lineno);
		}
	} else {
		list->children = 0;
		lineno = CG(zend_lineno);
	}
	list->lineno = lineno;

	return ast;
}
#else
static zend_ast *zend_ast_create_from_va_list(zend_ast_kind kind, zend_ast_attr attr, va_list va) {
	uint32_t i, children = kind >> ZEND_AST_NUM_CHILDREN_SHIFT;
	zend_ast *ast;

	ast = zend_ast_alloc(zend_ast_size(children));
	ast->kind = kind;
	ast->attr = attr;
	ast->lineno = (uint32_t) -1;

	for (i = 0; i < children; ++i) {
		ast->child[i] = va_arg(va, zend_ast *);
		if (ast->child[i] != NULL) {
			uint32_t lineno = zend_ast_get_lineno(ast->child[i]);
			if (lineno < ast->lineno) {
				ast->lineno = lineno;
			}
		}
	}

	if (ast->lineno == UINT_MAX) {
		ast->lineno = CG(zend_lineno);
	}

	return ast;
}

ZEND_API zend_ast *zend_ast_create_ex(zend_ast_kind kind, zend_ast_attr attr, ...) {
	va_list va;
	zend_ast *ast;

	va_start(va, attr);
	ast = zend_ast_create_from_va_list(kind, attr, va);
	va_end(va);

	return ast;
}

ZEND_API zend_ast *zend_ast_create(zend_ast_kind kind, ...) {
	va_list va;
	zend_ast *ast;

	va_start(va, kind);
	ast = zend_ast_create_from_va_list(kind, 0, va);
	va_end(va);

	return ast;
}

ZEND_API zend_ast *zend_ast_create_list(uint32_t init_children, zend_ast_kind kind, ...) {
	zend_ast *ast;
	zend_ast_list *list;

	ast = zend_ast_alloc(zend_ast_list_size(4));
	list = (zend_ast_list *) ast;
	list->kind = kind;
	list->attr = 0;
	list->lineno = CG(zend_lineno);
	list->children = 0;

	{
		va_list va;
		uint32_t i;
		va_start(va, kind);
		for (i = 0; i < init_children; ++i) {
			zend_ast *child = va_arg(va, zend_ast *);
			ast = zend_ast_list_add(ast, child);
			if (child != NULL) {
				uint32_t lineno = zend_ast_get_lineno(child);
				if (lineno < ast->lineno) {
					ast->lineno = lineno;
				}
			}
		}
		va_end(va);
	}

	return ast;
}
#endif

zend_ast *zend_ast_create_concat_op(zend_ast *op0, zend_ast *op1) {
	if (op0->kind == ZEND_AST_ZVAL && op1->kind == ZEND_AST_ZVAL) {
		zval *zv0 = zend_ast_get_zval(op0);
		zval *zv1 = zend_ast_get_zval(op1);
		if (!zend_binary_op_produces_error(ZEND_CONCAT, zv0, zv1) &&
				concat_function(zv0, zv0, zv1) == SUCCESS) {
			zval_ptr_dtor_nogc(zv1);
			return zend_ast_create_zval(zv0);
		}
	}
	return zend_ast_create_binary_op(ZEND_CONCAT, op0, op1);
}

static inline bool is_power_of_two(uint32_t n) {
	return ((n != 0) && (n == (n & (~n + 1))));
}

ZEND_API zend_ast * ZEND_FASTCALL zend_ast_list_add(zend_ast *ast, zend_ast *op) {
	zend_ast_list *list = zend_ast_get_list(ast);
	if (list->children >= 4 && is_power_of_two(list->children)) {
			list = zend_ast_realloc(list,
			zend_ast_list_size(list->children), zend_ast_list_size(list->children * 2));
	}
	list->child[list->children++] = op;
	return (zend_ast *) list;
}

static zend_result zend_ast_add_array_element(zval *result, zval *offset, zval *expr)
{
	if (Z_TYPE_P(offset) == IS_UNDEF) {
		if (!zend_hash_next_index_insert(Z_ARRVAL_P(result), expr)) {
			zend_throw_error(NULL,
				"Cannot add element to the array as the next element is already occupied");
			return FAILURE;
		}
		return SUCCESS;
	}

	if (array_set_zval_key(Z_ARRVAL_P(result), offset, expr) == FAILURE) {
		return FAILURE;
	}

	zval_ptr_dtor_nogc(offset);
	zval_ptr_dtor_nogc(expr);
	return SUCCESS;
}

static zend_result zend_ast_add_unpacked_element(zval *result, zval *expr) {
	if (EXPECTED(Z_TYPE_P(expr) == IS_ARRAY)) {
		HashTable *ht = Z_ARRVAL_P(expr);
		zval *val;
		zend_string *key;

		ZEND_HASH_FOREACH_STR_KEY_VAL(ht, key, val) {
			if (key) {
				zend_hash_update(Z_ARRVAL_P(result), key, val);
			} else {
				if (!zend_hash_next_index_insert(Z_ARRVAL_P(result), val)) {
					zend_throw_error(NULL,
						"Cannot add element to the array as the next element is already occupied");
					return FAILURE;
				}
			}
			Z_TRY_ADDREF_P(val);
		} ZEND_HASH_FOREACH_END();
		return SUCCESS;
	}

	zend_throw_error(NULL, "Only arrays can be unpacked in constant expression");
	return FAILURE;
}

zend_class_entry *zend_ast_fetch_class(zend_ast *ast, zend_class_entry *scope)
{
	return zend_fetch_class_with_scope(zend_ast_get_str(ast), (ast->attr >> ZEND_CONST_EXPR_NEW_FETCH_TYPE_SHIFT) | ZEND_FETCH_CLASS_EXCEPTION, scope);
}

static zend_result ZEND_FASTCALL zend_ast_evaluate_ex(zval *result, zend_ast *ast, zend_class_entry *scope, bool *short_circuited_ptr)
{
	zval op1, op2;
	zend_result ret = SUCCESS;
	*short_circuited_ptr = false;

	switch (ast->kind) {
		case ZEND_AST_BINARY_OP:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
			} else if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
				zval_ptr_dtor_nogc(&op1);
				ret = FAILURE;
			} else {
				binary_op_type op = get_binary_op(ast->attr);
				ret = op(result, &op1, &op2);
				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);
			}
			break;
		case ZEND_AST_GREATER:
		case ZEND_AST_GREATER_EQUAL:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
			} else if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
				zval_ptr_dtor_nogc(&op1);
				ret = FAILURE;
			} else {
				/* op1 > op2 is the same as op2 < op1 */
				binary_op_type op = ast->kind == ZEND_AST_GREATER
					? is_smaller_function : is_smaller_or_equal_function;
				ret = op(result, &op2, &op1);
				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);
			}
			break;
		case ZEND_AST_UNARY_OP:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
			} else {
				unary_op_type op = get_unary_op(ast->attr);
				ret = op(result, &op1);
				zval_ptr_dtor_nogc(&op1);
			}
			break;
		case ZEND_AST_ZVAL:
		{
			zval *zv = zend_ast_get_zval(ast);

			ZVAL_COPY(result, zv);
			break;
		}
		case ZEND_AST_CONSTANT:
		{
			zend_string *name = zend_ast_get_constant_name(ast);
			zval *zv = zend_get_constant_ex(name, scope, ast->attr);

			if (UNEXPECTED(zv == NULL)) {
				ZVAL_UNDEF(result);
				return FAILURE;
			}
			ZVAL_COPY_OR_DUP(result, zv);
			break;
		}
		case ZEND_AST_CONSTANT_CLASS:
			if (scope) {
				ZVAL_STR_COPY(result, scope->name);
			} else {
				ZVAL_EMPTY_STRING(result);
			}
			break;
		case ZEND_AST_CLASS_NAME:
			if (!scope) {
				zend_throw_error(NULL, "Cannot use \"self\" when no class scope is active");
				return FAILURE;
			}
			if (ast->attr == ZEND_FETCH_CLASS_SELF) {
				ZVAL_STR_COPY(result, scope->name);
			} else if (ast->attr == ZEND_FETCH_CLASS_PARENT) {
				if (!scope->parent) {
					zend_throw_error(NULL,
						"Cannot use \"parent\" when current class scope has no parent");
					return FAILURE;
				}
				ZVAL_STR_COPY(result, scope->parent->name);
			} else {
				ZEND_ASSERT(0 && "Should have errored during compilation");
			}
			break;
		case ZEND_AST_AND:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
				break;
			}
			if (zend_is_true(&op1)) {
				if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
					zval_ptr_dtor_nogc(&op1);
					ret = FAILURE;
					break;
				}
				ZVAL_BOOL(result, zend_is_true(&op2));
				zval_ptr_dtor_nogc(&op2);
			} else {
				ZVAL_FALSE(result);
			}
			zval_ptr_dtor_nogc(&op1);
			break;
		case ZEND_AST_OR:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
				break;
			}
			if (zend_is_true(&op1)) {
				ZVAL_TRUE(result);
			} else {
				if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
					zval_ptr_dtor_nogc(&op1);
					ret = FAILURE;
					break;
				}
				ZVAL_BOOL(result, zend_is_true(&op2));
				zval_ptr_dtor_nogc(&op2);
			}
			zval_ptr_dtor_nogc(&op1);
			break;
		case ZEND_AST_CONDITIONAL:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
				break;
			}
			if (zend_is_true(&op1)) {
				if (!ast->child[1]) {
					*result = op1;
				} else {
					if (UNEXPECTED(zend_ast_evaluate(result, ast->child[1], scope) != SUCCESS)) {
						zval_ptr_dtor_nogc(&op1);
						ret = FAILURE;
						break;
					}
					zval_ptr_dtor_nogc(&op1);
				}
			} else {
				if (UNEXPECTED(zend_ast_evaluate(result, ast->child[2], scope) != SUCCESS)) {
					zval_ptr_dtor_nogc(&op1);
					ret = FAILURE;
					break;
				}
				zval_ptr_dtor_nogc(&op1);
			}
			break;
		case ZEND_AST_COALESCE:
			if (UNEXPECTED(zend_ast_evaluate(&op1, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
				break;
			}
			if (Z_TYPE(op1) > IS_NULL) {
				*result = op1;
			} else {
				if (UNEXPECTED(zend_ast_evaluate(result, ast->child[1], scope) != SUCCESS)) {
					zval_ptr_dtor_nogc(&op1);
					ret = FAILURE;
					break;
				}
				zval_ptr_dtor_nogc(&op1);
			}
			break;
		case ZEND_AST_UNARY_PLUS:
			if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
			} else {
				ZVAL_LONG(&op1, 0);
				ret = add_function(result, &op1, &op2);
				zval_ptr_dtor_nogc(&op2);
			}
			break;
		case ZEND_AST_UNARY_MINUS:
			if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[0], scope) != SUCCESS)) {
				ret = FAILURE;
			} else {
				ZVAL_LONG(&op1, -1);
				ret = mul_function(result, &op1, &op2);
				zval_ptr_dtor_nogc(&op2);
			}
			break;
		case ZEND_AST_ARRAY:
			{
				uint32_t i;
				zend_ast_list *list = zend_ast_get_list(ast);

				if (!list->children) {
					ZVAL_EMPTY_ARRAY(result);
					break;
				}
				array_init(result);
				for (i = 0; i < list->children; i++) {
					zend_ast *elem = list->child[i];
					if (elem->kind == ZEND_AST_UNPACK) {
						if (UNEXPECTED(zend_ast_evaluate(&op1, elem->child[0], scope) != SUCCESS)) {
							zval_ptr_dtor_nogc(result);
							return FAILURE;
						}
						if (UNEXPECTED(zend_ast_add_unpacked_element(result, &op1) != SUCCESS)) {
							zval_ptr_dtor_nogc(&op1);
							zval_ptr_dtor_nogc(result);
							return FAILURE;
						}
						zval_ptr_dtor_nogc(&op1);
						continue;
					}
					if (elem->child[1]) {
						if (UNEXPECTED(zend_ast_evaluate(&op1, elem->child[1], scope) != SUCCESS)) {
							zval_ptr_dtor_nogc(result);
							return FAILURE;
						}
					} else {
						ZVAL_UNDEF(&op1);
					}
					if (UNEXPECTED(zend_ast_evaluate(&op2, elem->child[0], scope) != SUCCESS)) {
						zval_ptr_dtor_nogc(&op1);
						zval_ptr_dtor_nogc(result);
						return FAILURE;
					}
					if (UNEXPECTED(zend_ast_add_array_element(result, &op1, &op2) != SUCCESS)) {
						zval_ptr_dtor_nogc(&op1);
						zval_ptr_dtor_nogc(&op2);
						zval_ptr_dtor_nogc(result);
						return FAILURE;
					}
				}
			}
			break;
		case ZEND_AST_DIM:
			if (ast->child[1] == NULL) {
				zend_error_noreturn(E_COMPILE_ERROR, "Cannot use [] for reading");
			}

			bool short_circuited;
			if (UNEXPECTED(zend_ast_evaluate_ex(&op1, ast->child[0], scope, &short_circuited) != SUCCESS)) {
				ret = FAILURE;
				break;
			}
			if (short_circuited) {
				*short_circuited_ptr = true;
				ZVAL_NULL(result);
				return SUCCESS;
			}

			// DIM on objects is disallowed because it allows executing arbitrary expressions
			if (Z_TYPE(op1) == IS_OBJECT) {
				zval_ptr_dtor_nogc(&op1);
				zend_throw_error(NULL, "Cannot use [] on objects in constant expression");
				ret = FAILURE;
				break;
			}

			if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
				zval_ptr_dtor_nogc(&op1);
				ret = FAILURE;
				break;
			}

			zend_fetch_dimension_const(result, &op1, &op2, (ast->attr & ZEND_DIM_IS) ? BP_VAR_IS : BP_VAR_R);

			zval_ptr_dtor_nogc(&op1);
			zval_ptr_dtor_nogc(&op2);
			if (UNEXPECTED(EG(exception))) {
				return FAILURE;
			}

			break;
		case ZEND_AST_CONST_ENUM_INIT:
		{
			// Preloading will attempt to resolve constants but objects can't be stored in shm
			// Aborting here to store the const AST instead
			if (CG(in_compilation)) {
				return FAILURE;
			}

			zend_ast *class_name_ast = ast->child[0];
			zend_string *class_name = zend_ast_get_str(class_name_ast);

			zend_ast *case_name_ast = ast->child[1];
			zend_string *case_name = zend_ast_get_str(case_name_ast);

			zend_ast *case_value_ast = ast->child[2];

			zval case_value_zv;
			ZVAL_UNDEF(&case_value_zv);
			if (case_value_ast != NULL) {
				if (UNEXPECTED(zend_ast_evaluate(&case_value_zv, case_value_ast, scope) != SUCCESS)) {
					return FAILURE;
				}
			}

			zend_class_entry *ce = zend_lookup_class(class_name);
			zend_enum_new(result, ce, case_name, case_value_ast != NULL ? &case_value_zv : NULL);
			zval_ptr_dtor_nogc(&case_value_zv);
			break;
		}
		case ZEND_AST_CLASS_CONST:
		{
			zend_string *class_name = zend_ast_get_str(ast->child[0]);
			zend_string *const_name = zend_ast_get_str(ast->child[1]);

			zend_string *previous_filename;
			zend_long previous_lineno;
			if (scope) {
				previous_filename = EG(filename_override);
				previous_lineno = EG(lineno_override);
				EG(filename_override) = scope->info.user.filename;
				EG(lineno_override) = zend_ast_get_lineno(ast);
			}
			zval *zv = zend_get_class_constant_ex(class_name, const_name, scope, ast->attr);
			if (scope) {
				EG(filename_override) = previous_filename;
				EG(lineno_override) = previous_lineno;
			}

			if (UNEXPECTED(zv == NULL)) {
				ZVAL_UNDEF(result);
				return FAILURE;
			}
			ZVAL_COPY_OR_DUP(result, zv);
			break;
		}
		case ZEND_AST_NEW:
		{
			zend_class_entry *ce = zend_ast_fetch_class(ast->child[0], scope);
			if (!ce) {
				return FAILURE;
			}

			if (object_init_ex(result, ce) != SUCCESS) {
				return FAILURE;
			}

			zend_ast_list *args_ast = zend_ast_get_list(ast->child[1]);
			if (args_ast->attr) {
				/* Has named arguments. */
				HashTable *args = zend_new_array(args_ast->children);
				for (uint32_t i = 0; i < args_ast->children; i++) {
					zend_ast *arg_ast = args_ast->child[i];
					zend_string *name = NULL;
					zval arg;
					if (arg_ast->kind == ZEND_AST_NAMED_ARG) {
						name = zend_ast_get_str(arg_ast->child[0]);
						arg_ast = arg_ast->child[1];
					}
					if (zend_ast_evaluate(&arg, arg_ast, scope) == FAILURE) {
						zend_array_destroy(args);
						zval_ptr_dtor(result);
						return FAILURE;
					}
					if (name) {
						if (!zend_hash_add(args, name, &arg)) {
							zend_throw_error(NULL,
								"Named parameter $%s overwrites previous argument",
								ZSTR_VAL(name));
							zend_array_destroy(args);
							zval_ptr_dtor(result);
							return FAILURE;
						}
					} else {
						zend_hash_next_index_insert(args, &arg);
					}
				}

				zend_function *ctor = Z_OBJ_HT_P(result)->get_constructor(Z_OBJ_P(result));
				if (ctor) {
					zend_call_known_function(
						ctor, Z_OBJ_P(result), Z_OBJCE_P(result), NULL, 0, NULL, args);
				}

				zend_array_destroy(args);
			} else {
				ALLOCA_FLAG(use_heap)
				zval *args = do_alloca(sizeof(zval) * args_ast->children, use_heap);
				for (uint32_t i = 0; i < args_ast->children; i++) {
					if (zend_ast_evaluate(&args[i], args_ast->child[i], scope) == FAILURE) {
						for (uint32_t j = 0; j < i; j++) {
							zval_ptr_dtor(&args[j]);
						}
						free_alloca(args, use_heap);
						zval_ptr_dtor(result);
						return FAILURE;
					}
				}

				zend_function *ctor = Z_OBJ_HT_P(result)->get_constructor(Z_OBJ_P(result));
				if (ctor) {
					zend_call_known_instance_method(
						ctor, Z_OBJ_P(result), NULL, args_ast->children, args);
				}

				for (uint32_t i = 0; i < args_ast->children; i++) {
					zval_ptr_dtor(&args[i]);
				}
				free_alloca(args, use_heap);
			}

			if (EG(exception)) {
				zend_object_store_ctor_failed(Z_OBJ_P(result));
				zval_ptr_dtor(result);
				return FAILURE;
			}
			return SUCCESS;
		}
		case ZEND_AST_PROP:
		case ZEND_AST_NULLSAFE_PROP:
		{
			bool short_circuited;
			if (UNEXPECTED(zend_ast_evaluate_ex(&op1, ast->child[0], scope, &short_circuited) != SUCCESS)) {
				return FAILURE;
			}
			if (short_circuited) {
				*short_circuited_ptr = true;
				ZVAL_NULL(result);
				return SUCCESS;
			}
			if (ast->kind == ZEND_AST_NULLSAFE_PROP && Z_TYPE(op1) == IS_NULL) {
				*short_circuited_ptr = true;
				ZVAL_NULL(result);
				return SUCCESS;
			}

			if (UNEXPECTED(zend_ast_evaluate(&op2, ast->child[1], scope) != SUCCESS)) {
				zval_ptr_dtor_nogc(&op1);
				return FAILURE;
			}

			if (!try_convert_to_string(&op2)) {
				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);
				return FAILURE;
			}

			if (Z_TYPE(op1) != IS_OBJECT) {
				zend_wrong_property_read(&op1, &op2);

				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);

				ZVAL_NULL(result);
				return SUCCESS;
			}

			zend_object *zobj = Z_OBJ(op1);
			if (!(zobj->ce->ce_flags & ZEND_ACC_ENUM)) {
				zend_throw_error(NULL, "Fetching properties on non-enums in constant expressions is not allowed");
				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);
				return FAILURE;
			}

			zend_string *name = Z_STR(op2);
			zval *property_result = zend_read_property_ex(scope, zobj, name, 0, result);
			if (EG(exception)) {
				zval_ptr_dtor_nogc(&op1);
				zval_ptr_dtor_nogc(&op2);
				return FAILURE;
			}

			if (result != property_result) {
				ZVAL_COPY(result, property_result);
			}
			zval_ptr_dtor_nogc(&op1);
			zval_ptr_dtor_nogc(&op2);
			return SUCCESS;
		}
		default:
			zend_throw_error(NULL, "Unsupported constant expression");
			ret = FAILURE;
	}
	return ret;
}

ZEND_API zend_result ZEND_FASTCALL zend_ast_evaluate(zval *result, zend_ast *ast, zend_class_entry *scope)
{
	bool short_circuited;
	return zend_ast_evaluate_ex(result, ast, scope, &short_circuited);
}

static size_t ZEND_FASTCALL zend_ast_tree_size(zend_ast *ast)
{
	size_t size;

	if (ast->kind == ZEND_AST_ZVAL || ast->kind == ZEND_AST_CONSTANT) {
		size = sizeof(zend_ast_zval);
	} else if (zend_ast_is_list(ast)) {
		uint32_t i;
		zend_ast_list *list = zend_ast_get_list(ast);

		size = zend_ast_list_size(list->children);
		for (i = 0; i < list->children; i++) {
			if (list->child[i]) {
				size += zend_ast_tree_size(list->child[i]);
			}
		}
	} else {
		uint32_t i, children = zend_ast_get_num_children(ast);