Hacky proof of concept implementation

Zend/zend_compile.c

@@ -6640,6 +6640,13 @@ void zend_do_qm_false(znode *result, const znode *false_value, const znode *qm_t
 }
 /* }}} */
 
+void zend_do_inherit_parent_symtable(TSRMLS_D) /* {{{ */
+{
+	zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);
+	opline->opcode = ZEND_INHERIT_PARENT_SYMTABLE;
+}
+/* }}} */
+
 void zend_do_extended_info(TSRMLS_D) /* {{{ */
 {
 	zend_op *opline;

Zend/zend_compile.h

@@ -629,6 +629,8 @@ void zend_do_goto(const znode *label TSRMLS_DC);
 void zend_resolve_goto_label(zend_op_array *op_array, zend_op *opline, int pass2 TSRMLS_DC);
 void zend_release_labels(TSRMLS_D);
 
+void zend_do_inherit_parent_symtable(TSRMLS_D);
+
 ZEND_API void function_add_ref(zend_function *function);
 
 #define INITIAL_OP_ARRAY_SIZE 64

Zend/zend_ini_scanner.c

@@ -1,4 +1,4 @@
-/* Generated by re2c 0.13.5 on Sat Feb 25 22:04:14 2012 */
+/* Generated by re2c 0.13.5 on Wed Jun 27 22:28:45 2012 */
 #line 1 "Zend/zend_ini_scanner.l"
 /*
    +----------------------------------------------------------------------+

Zend/zend_ini_scanner_defs.h

@@ -1,4 +1,4 @@
-/* Generated by re2c 0.13.5 on Sat Feb 25 22:04:14 2012 */
+/* Generated by re2c 0.13.5 on Wed Jun 27 22:28:45 2012 */
 #line 3 "Zend/zend_ini_scanner_defs.h"
 
 enum YYCONDTYPE {

Zend/zend_language_parser.y

@@ -811,6 +811,72 @@ expr_without_variable:
 	|	T_STATIC function is_generator is_reference { zend_do_begin_lambda_function_declaration(&$$, &$2, $3.op_type, $4.op_type, 1 TSRMLS_CC); }
 		'(' parameter_list ')' lexical_vars { zend_do_suspend_if_generator(TSRMLS_C); }
 		'{' inner_statement_list '}' { zend_do_end_function_declaration(&$2 TSRMLS_CC); $$ = $5; }
+	|	'(' {
+			zend_do_begin_lambda_function_declaration(&$$, &$1, 1, 0, 0 TSRMLS_CC);
+			zend_do_inherit_parent_symtable(TSRMLS_C);
+			zend_do_suspend_if_generator(TSRMLS_C);
+		}
+		generator_expression_foreach
+		')' {
+			zend_do_end_function_declaration(&$1 TSRMLS_CC);
+
+			zend_do_begin_dynamic_function_call(&$2, 0 TSRMLS_CC);
+			{
+				znode param_count_node;
+				Z_LVAL(param_count_node.u.constant) = 0;
+				zend_do_end_function_call(&$2, &$$, &param_count_node, 0, 1 TSRMLS_CC);
+			}
+			zend_do_extended_fcall_end(TSRMLS_C);
+		}
+	|	'[' {
+			zend_do_begin_lambda_function_declaration(&$$, &$1, 1, 0, 0 TSRMLS_CC);
+			zend_do_inherit_parent_symtable(TSRMLS_C);
+			zend_do_suspend_if_generator(TSRMLS_C);
+		}
+		generator_expression_foreach
+		']' {
+			znode generator_instance_node;
+
+			zend_do_end_function_declaration(&$1 TSRMLS_CC);
+
+			zend_do_begin_dynamic_function_call(&$2, 0 TSRMLS_CC);
+			{
+				znode param_count_node;
+				Z_LVAL(param_count_node.u.constant) = 0;
+				zend_do_end_function_call(&$2, &generator_instance_node, &param_count_node, 0, 1 TSRMLS_CC);
+			}
+			zend_do_extended_fcall_end(TSRMLS_C);
+
+			{
+				znode function_node, param_count_node;
+
+				function_node.op_type = IS_CONST;
+				ZVAL_STRING(&function_node.u.constant, "iterator_to_array", 1);
+
+				Z_LVAL(param_count_node.u.constant) = 1;
+
+				zend_do_begin_function_call(&function_node, 0 TSRMLS_CC);
+				zend_do_pass_param(&generator_instance_node, ZEND_SEND_VAL, 1 TSRMLS_CC);
+				zend_do_end_function_call(&function_node, &$$, &param_count_node, 0, 0 TSRMLS_CC);
+				zend_do_extended_fcall_end(TSRMLS_C);
+			}
+		}
+;
+
+generator_expression_foreach:
+		T_FOREACH '(' variable T_AS { zend_do_foreach_begin(&$1, &$2, &$3, &$4, 1 TSRMLS_CC); }
+		foreach_variable foreach_optional_arg ')' { zend_do_foreach_cont(&$1, &$2, &$4, &$6, &$7 TSRMLS_CC); }
+		generator_expression_content { zend_do_foreach_end(&$1, &$4 TSRMLS_CC); }
+	|	T_FOREACH '(' expr_without_variable T_AS { zend_do_foreach_begin(&$1, &$2, &$3, &$4, 0 TSRMLS_CC); }
+		variable foreach_optional_arg ')' { zend_check_writable_variable(&$6); zend_do_foreach_cont(&$1, &$2, &$4, &$6, &$7 TSRMLS_CC); }
+		generator_expression_content { zend_do_foreach_end(&$1, &$4 TSRMLS_CC); }
+;
+
+generator_expression_content:
+		generator_expression_foreach
+	|	T_IF '(' expr ')' { zend_do_if_cond(&$3, &$4 TSRMLS_CC); } generator_expression_content { zend_do_if_after_statement(&$4, 1 TSRMLS_CC); zend_do_if_end(TSRMLS_C); }
+	|	T_YIELD expr { zend_do_yield(&$$, &$2, NULL TSRMLS_CC); }
+	|	T_YIELD expr T_DOUBLE_ARROW expr { zend_do_yield(&$$, &$4, &$2 TSRMLS_CC); }
 ;
 
 combined_scalar_offset:

Zend/zend_vm_def.h

@@ -2395,14 +2395,14 @@ ZEND_VM_HANDLER(59, ZEND_INIT_FCALL_BY_NAME, ANY, CONST|TMP|VAR|CV)
 			EX(object) = NULL;
 			CHECK_EXCEPTION();
 			ZEND_VM_NEXT_OPCODE();
-		} else if (OP2_TYPE != IS_CONST && OP2_TYPE != IS_TMP_VAR &&
+		} else if (OP2_TYPE != IS_CONST &&
 		    EXPECTED(Z_TYPE_P(function_name) == IS_OBJECT) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure)(function_name, &EX(called_scope), &EX(fbc), &EX(object) TSRMLS_CC) == SUCCESS) {
 			if (EX(object)) {
 				Z_ADDREF_P(EX(object));
 			}
-			if (OP2_TYPE == IS_VAR && OP2_FREE &&
+			if (OP2_TYPE != IS_CV && OP2_FREE &&
 			    EX(fbc)->common.fn_flags & ZEND_ACC_CLOSURE) {
 				/* Delay closure destruction until its invocation */
 				EX(fbc)->common.prototype = (zend_function*)function_name;
@@ -5237,6 +5237,7 @@ ZEND_VM_HANDLER(159, ZEND_SUSPEND_AND_RETURN_GENERATOR, ANY, ANY)
 
 		EX(current_scope) = EG(scope);
 		EX(current_called_scope) = EG(called_scope);
+		EX(symbol_table) = EG(active_symbol_table);
 
 		if (EG(This)) {
 			Z_ADDREF_P(EG(This));
@@ -5421,4 +5422,27 @@ ZEND_VM_HANDLER(161, ZEND_DELEGATE_YIELD, CONST|TMP|VAR|CV, ANY)
 	ZEND_VM_NEXT_OPCODE();
 }
 
+ZEND_VM_HANDLER(162, ZEND_INHERIT_PARENT_SYMTABLE, ANY, ANY)
+{
+	HashTable *symbol_table;
+
+	/* Make sure that the parent scope has a symbol table. As
+	 * zend_rebuild_symbol_table() acts upon EG(current_execute_data) we
+	 * have to temporarily set it to the parent scope and then set it back. */
+	EG(current_execute_data) = EX(prev_execute_data);
+	zend_rebuild_symbol_table(TSRMLS_C);
+	EG(current_execute_data) = execute_data;
+
+	/* Create a new symbol table into which the parent symbol table is copied.
+	 * The parent symbol table was put into EG(active_symbol_table) by
+	 * zend_rebuild_symbol_table(). Then set EG(active_symbol_table) to the
+	 * newly created copy of the parent table. */
+	ALLOC_HASHTABLE(symbol_table);
+	zend_hash_init(symbol_table, zend_hash_num_elements(EG(active_symbol_table)), NULL, ZVAL_PTR_DTOR, 0);
+	zend_hash_copy(symbol_table, EG(active_symbol_table), (copy_ctor_func_t) zval_add_ref, NULL, sizeof(zval *));
+	EG(active_symbol_table) = symbol_table;
+
+	ZEND_VM_NEXT_OPCODE();
+}
+
 ZEND_VM_EXPORT_HELPER(zend_do_fcall, zend_do_fcall_common_helper)

Zend/zend_vm_execute.h

@@ -1220,6 +1220,7 @@ static int ZEND_FASTCALL  ZEND_SUSPEND_AND_RETURN_GENERATOR_SPEC_HANDLER(ZEND_OP
 
 		EX(current_scope) = EG(scope);
 		EX(current_called_scope) = EG(called_scope);
+		EX(symbol_table) = EG(active_symbol_table);
 
 		if (EG(This)) {
 			Z_ADDREF_P(EG(This));
@@ -1296,6 +1297,29 @@ static int ZEND_FASTCALL  ZEND_SUSPEND_AND_RETURN_GENERATOR_SPEC_HANDLER(ZEND_OP
 	ZEND_VM_LEAVE();
 }
 
+static int ZEND_FASTCALL  ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
+{
+	HashTable *symbol_table;
+
+	/* Make sure that the parent scope has a symbol table. As
+	 * zend_rebuild_symbol_table() acts upon EG(current_execute_data) we
+	 * have to temporarily set it to the parent scope and then set it back. */
+	EG(current_execute_data) = EX(prev_execute_data);
+	zend_rebuild_symbol_table(TSRMLS_C);
+	EG(current_execute_data) = execute_data;
+
+	/* Create a new symbol table into which the parent symbol table is copied.
+	 * The parent symbol table was put into EG(active_symbol_table) by
+	 * zend_rebuild_symbol_table(). Then set EG(active_symbol_table) to the
+	 * newly created copy of the parent table. */
+	ALLOC_HASHTABLE(symbol_table);
+	zend_hash_init(symbol_table, zend_hash_num_elements(EG(active_symbol_table)), NULL, ZVAL_PTR_DTOR, 0);
+	zend_hash_copy(symbol_table, EG(active_symbol_table), (copy_ctor_func_t) zval_add_ref, NULL, sizeof(zval *));
+	EG(active_symbol_table) = symbol_table;
+
+	ZEND_VM_NEXT_OPCODE();
+}
+
 static int ZEND_FASTCALL  ZEND_FETCH_CLASS_SPEC_CONST_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
 {
 	USE_OPLINE
@@ -1374,14 +1398,14 @@ static int ZEND_FASTCALL  ZEND_INIT_FCALL_BY_NAME_SPEC_CONST_HANDLER(ZEND_OPCODE
 			EX(object) = NULL;
 			CHECK_EXCEPTION();
 			ZEND_VM_NEXT_OPCODE();
-		} else if (IS_CONST != IS_CONST && IS_CONST != IS_TMP_VAR &&
+		} else if (IS_CONST != IS_CONST &&
 		    EXPECTED(Z_TYPE_P(function_name) == IS_OBJECT) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure)(function_name, &EX(called_scope), &EX(fbc), &EX(object) TSRMLS_CC) == SUCCESS) {
 			if (EX(object)) {
 				Z_ADDREF_P(EX(object));
 			}
-			if (IS_CONST == IS_VAR && 0 &&
+			if (IS_CONST != IS_CV && 0 &&
 			    EX(fbc)->common.fn_flags & ZEND_ACC_CLOSURE) {
 				/* Delay closure destruction until its invocation */
 				EX(fbc)->common.prototype = (zend_function*)function_name;
@@ -1676,14 +1700,14 @@ static int ZEND_FASTCALL  ZEND_INIT_FCALL_BY_NAME_SPEC_TMP_HANDLER(ZEND_OPCODE_H
 			EX(object) = NULL;
 			CHECK_EXCEPTION();
 			ZEND_VM_NEXT_OPCODE();
-		} else if (IS_TMP_VAR != IS_CONST && IS_TMP_VAR != IS_TMP_VAR &&
+		} else if (IS_TMP_VAR != IS_CONST &&
 		    EXPECTED(Z_TYPE_P(function_name) == IS_OBJECT) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure)(function_name, &EX(called_scope), &EX(fbc), &EX(object) TSRMLS_CC) == SUCCESS) {
 			if (EX(object)) {
 				Z_ADDREF_P(EX(object));
 			}
-			if (IS_TMP_VAR == IS_VAR && 1 &&
+			if (IS_TMP_VAR != IS_CV && 1 &&
 			    EX(fbc)->common.fn_flags & ZEND_ACC_CLOSURE) {
 				/* Delay closure destruction until its invocation */
 				EX(fbc)->common.prototype = (zend_function*)function_name;
@@ -1840,14 +1864,14 @@ static int ZEND_FASTCALL  ZEND_INIT_FCALL_BY_NAME_SPEC_VAR_HANDLER(ZEND_OPCODE_H
 			EX(object) = NULL;
 			CHECK_EXCEPTION();
 			ZEND_VM_NEXT_OPCODE();
-		} else if (IS_VAR != IS_CONST && IS_VAR != IS_TMP_VAR &&
+		} else if (IS_VAR != IS_CONST &&
 		    EXPECTED(Z_TYPE_P(function_name) == IS_OBJECT) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure)(function_name, &EX(called_scope), &EX(fbc), &EX(object) TSRMLS_CC) == SUCCESS) {
 			if (EX(object)) {
 				Z_ADDREF_P(EX(object));
 			}
-			if (IS_VAR == IS_VAR && (free_op2.var != NULL) &&
+			if (IS_VAR != IS_CV && (free_op2.var != NULL) &&
 			    EX(fbc)->common.fn_flags & ZEND_ACC_CLOSURE) {
 				/* Delay closure destruction until its invocation */
 				EX(fbc)->common.prototype = (zend_function*)function_name;
@@ -2037,14 +2061,14 @@ static int ZEND_FASTCALL  ZEND_INIT_FCALL_BY_NAME_SPEC_CV_HANDLER(ZEND_OPCODE_HA
 			EX(object) = NULL;
 			CHECK_EXCEPTION();
 			ZEND_VM_NEXT_OPCODE();
-		} else if (IS_CV != IS_CONST && IS_CV != IS_TMP_VAR &&
+		} else if (IS_CV != IS_CONST &&
 		    EXPECTED(Z_TYPE_P(function_name) == IS_OBJECT) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure) &&
 			Z_OBJ_HANDLER_P(function_name, get_closure)(function_name, &EX(called_scope), &EX(fbc), &EX(object) TSRMLS_CC) == SUCCESS) {
 			if (EX(object)) {
 				Z_ADDREF_P(EX(object));
 			}
-			if (IS_CV == IS_VAR && 0 &&
+			if (IS_CV != IS_CV && 0 &&
 			    EX(fbc)->common.fn_flags & ZEND_ACC_CLOSURE) {
 				/* Delay closure destruction until its invocation */
 				EX(fbc)->common.prototype = (zend_function*)function_name;
@@ -43600,6 +43624,31 @@ void zend_init_opcodes_handlers(void)
   	ZEND_DELEGATE_YIELD_SPEC_CV_HANDLER,
   	ZEND_DELEGATE_YIELD_SPEC_CV_HANDLER,
   	ZEND_DELEGATE_YIELD_SPEC_CV_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
+  	ZEND_INHERIT_PARENT_SYMTABLE_SPEC_HANDLER,
   	ZEND_NULL_HANDLER
   };
   zend_opcode_handlers = (opcode_handler_t*)labels;

Zend/zend_vm_opcodes.h

@@ -162,3 +162,4 @@
 #define ZEND_SUSPEND_AND_RETURN_GENERATOR    159
 #define ZEND_YIELD                           160
 #define ZEND_DELEGATE_YIELD                  161
+#define ZEND_INHERIT_PARENT_SYMTABLE         162