Revert "Remove loop_var_stack"

This reverts commit b3a4c05071c3786e27e1326fa1b4d5acad62fccd.

4 files changed, 79 insertions, 30 deletions

diff --git a/Zend/zend.c b/Zend/zend.c
index e200c05b67..e5fd2e8bee 100644
--- a/Zend/zend.c
+++ b/Zend/zend.c
@@ -1045,6 +1045,7 @@ static void zend_error_va_list(int type, const char *format, va_list args)
 	zval orig_user_error_handler;
 	zend_bool in_compilation;
 	zend_class_entry *saved_class_entry;
+	zend_stack loop_var_stack;
 	zend_stack delayed_oplines_stack;
 	zend_array *symbol_table;
 
@@ -1211,6 +1212,7 @@ static void zend_error_va_list(int type, const char *format, va_list args)
 			if (in_compilation) {
 				saved_class_entry = CG(active_class_entry);
 				CG(active_class_entry) = NULL;
+				SAVE_STACK(loop_var_stack);
 				SAVE_STACK(delayed_oplines_stack);
 				CG(in_compilation) = 0;
 			}
@@ -1229,6 +1231,7 @@ static void zend_error_va_list(int type, const char *format, va_list args)
 
 			if (in_compilation) {
 				CG(active_class_entry) = saved_class_entry;
+				RESTORE_STACK(loop_var_stack);
 				RESTORE_STACK(delayed_oplines_stack);
 				CG(in_compilation) = 1;
 			}
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 51eb0bc754..69aecc4108 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -289,6 +289,7 @@ void zend_file_context_end(zend_file_context *prev_context) /* {{{ */
 
 void zend_init_compiler_data_structures(void) /* {{{ */
 {
+	zend_stack_init(&CG(loop_var_stack), sizeof(znode));
 	zend_stack_init(&CG(delayed_oplines_stack), sizeof(zend_op));
 	CG(active_class_entry) = NULL;
 	CG(in_compilation) = 0;
@@ -321,6 +322,7 @@ void init_compiler(void) /* {{{ */
 
 void shutdown_compiler(void) /* {{{ */
 {
+	zend_stack_destroy(&CG(loop_var_stack));
 	zend_stack_destroy(&CG(delayed_oplines_stack));
 	zend_hash_destroy(&CG(filenames_table));
 	zend_hash_destroy(&CG(const_filenames));
@@ -569,10 +571,14 @@ static inline void zend_begin_loop(const znode *loop_var) /* {{{ */
 	CG(context).current_brk_cont = CG(context).last_brk_cont;
 	brk_cont_element = get_next_brk_cont_element(CG(active_op_array));
 	brk_cont_element->parent = parent;
-	if (loop_var && (loop_var->op_type & (IS_TMP_VAR|IS_VAR))) {
-		brk_cont_element->loop_var = *loop_var;
+
+	if (loop_var) {
+		zend_stack_push(&CG(loop_var_stack), loop_var);
+		brk_cont_element->start = get_next_op_number(CG(active_op_array));
 	} else {
-		brk_cont_element->loop_var.op_type = IS_UNUSED;
+		/* The start field is used to free temporary variables in case of exceptions.
+		 * We won't try to free something of we don't have loop variable.  */
+		brk_cont_element->start = -1;
 	}
 }
 /* }}} */
@@ -584,6 +590,10 @@ static inline void zend_end_loop(int cont_addr) /* {{{ */
 	brk_cont_element->cont = cont_addr;
 	brk_cont_element->brk = get_next_op_number(CG(active_op_array));
 	CG(context).current_brk_cont = brk_cont_element->parent;
+
+	if (brk_cont_element->start >= 0) {
+		zend_stack_del_top(&CG(loop_var_stack));
+	}
 }
 /* }}} */
 
@@ -872,15 +882,24 @@ static void str_dtor(zval *zv)  /* {{{ */ {
 
 static zend_bool zend_is_call(zend_ast *ast);
 
-static void generate_free_loop_var(znode *var) /* {{{ */
+static int generate_free_loop_var(znode *var) /* {{{ */
 {
-	if (var->op_type != IS_UNUSED) {
-		zend_op *opline = get_next_op(CG(active_op_array));
+	switch (var->op_type) {
+		case IS_UNUSED:
+			/* Stack separator on function boundary, stop applying */
+			return 1;
+		case IS_VAR:
+		case IS_TMP_VAR:
+		{
+			zend_op *opline = get_next_op(CG(active_op_array));
 
-		opline->opcode = var->flag ? ZEND_FE_FREE : ZEND_FREE;
-		SET_NODE(opline->op1, var);
-		SET_UNUSED(opline->op2);
+			opline->opcode = var->flag ? ZEND_FE_FREE : ZEND_FREE;
+			SET_NODE(opline->op1, var);
+			SET_UNUSED(opline->op2);
+		}
 	}
+
+	return 0;
 }
 /* }}} */
 
@@ -3443,12 +3462,7 @@ void zend_compile_unset(zend_ast *ast) /* {{{ */
 
 static void zend_free_foreach_and_switch_variables(void) /* {{{ */
 {
-	int array_offset = CG(context).current_brk_cont;
-	while (array_offset != -1) {
-		zend_brk_cont_element *brk_cont = &CG(context).brk_cont_array[array_offset];
-		generate_free_loop_var(&brk_cont->loop_var);
-		array_offset = brk_cont->parent;
-	}
+	zend_stack_apply(&CG(loop_var_stack), ZEND_STACK_APPLY_TOPDOWN, (int (*)(void *element)) generate_free_loop_var);
 }
 /* }}} */
 
@@ -3550,6 +3564,7 @@ void zend_compile_break_continue(zend_ast *ast) /* {{{ */
 	} else {
 		int array_offset = CG(context).current_brk_cont;
 		zend_long nest_level = depth;
+		znode *loop_var = zend_stack_top(&CG(loop_var_stack));
 
 		do {
 			if (array_offset == -1) {
@@ -3558,8 +3573,9 @@ void zend_compile_break_continue(zend_ast *ast) /* {{{ */
 					depth, depth == 1 ? "" : "s");
 			}
 
-			if (nest_level > 1) {
-				generate_free_loop_var(&CG(context).brk_cont_array[array_offset].loop_var);
+			if (nest_level > 1 && CG(context).brk_cont_array[array_offset].start >= 0) {
+				generate_free_loop_var(loop_var);
+				loop_var--;
 			}
 
 			array_offset = CG(context).brk_cont_array[array_offset].parent;
@@ -3576,6 +3592,7 @@ void zend_resolve_goto_label(zend_op_array *op_array, znode *label_node, zend_op
 	zend_label *dest;
 	int current, distance, free_vars;
 	zval *label;
+	znode *loop_var = NULL;
 
 	if (pass2_opline) {
 		label = RT_CONSTANT(op_array, pass2_opline->op2);
@@ -3596,7 +3613,7 @@ void zend_resolve_goto_label(zend_op_array *op_array, znode *label_node, zend_op
 
 			current = CG(context).current_brk_cont;
 			while (current != -1) {
-				if (CG(context).brk_cont_array[current].loop_var.op_type != IS_UNUSED) {
+				if (CG(context).brk_cont_array[current].start >= 0) {
 					zend_emit_op(NULL, ZEND_NOP, NULL, NULL);
 				}
 				current = CG(context).brk_cont_array[current].parent;
@@ -3616,6 +3633,9 @@ void zend_resolve_goto_label(zend_op_array *op_array, znode *label_node, zend_op
 	} else {
 		current = CG(context).current_brk_cont;
 	}
+	if (!pass2_opline) {
+		loop_var = zend_stack_top(&CG(loop_var_stack));
+	}
 	for (distance = 0, free_vars = 0; current != dest->brk_cont; distance++) {
 		if (current == -1) {
 			if (pass2_opline) {
@@ -3625,11 +3645,12 @@ void zend_resolve_goto_label(zend_op_array *op_array, znode *label_node, zend_op
 			}
 			zend_error_noreturn(E_COMPILE_ERROR, "'goto' into loop or switch statement is disallowed");
 		}
-		if (CG(context).brk_cont_array[current].loop_var.op_type != IS_UNUSED) {
+		if (CG(context).brk_cont_array[current].start >= 0) {
 			if (pass2_opline) {
 				free_vars++;
 			} else {
-				generate_free_loop_var(&CG(context).brk_cont_array[current].loop_var);
+				generate_free_loop_var(loop_var);
+				loop_var--;
 			}
 		}
 		current = CG(context).brk_cont_array[current].parent;
@@ -3639,18 +3660,30 @@ void zend_resolve_goto_label(zend_op_array *op_array, znode *label_node, zend_op
 		if (free_vars) {
 			current = pass2_opline->extended_value;
 			while (current != dest->brk_cont) {
-				if (CG(context).brk_cont_array[current].loop_var.op_type != IS_UNUSED) {
+				if (CG(context).brk_cont_array[current].start >= 0) {
 					zend_op *brk_opline = &op_array->opcodes[CG(context).brk_cont_array[current].brk];
 
-					(pass2_opline - free_vars)->opcode = brk_opline->opcode;
-					(pass2_opline - free_vars)->op1_type = brk_opline->op1_type;
-					if (op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) {
-						(pass2_opline - free_vars)->op1.var = brk_opline->op1.var;
-					} else {
-						(pass2_opline - free_vars)->op1.var = (uint32_t)(zend_intptr_t)ZEND_CALL_VAR_NUM(NULL, op_array->last_var + brk_opline->op1.var);
-						ZEND_VM_SET_OPCODE_HANDLER(pass2_opline - free_vars);
+					if (brk_opline->opcode == ZEND_FREE) {
+						(pass2_opline - free_vars)->opcode = ZEND_FREE;
+						(pass2_opline - free_vars)->op1_type = brk_opline->op1_type;
+						if (op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) {
+							(pass2_opline - free_vars)->op1.var = brk_opline->op1.var;
+						} else {
+							(pass2_opline - free_vars)->op1.var = (uint32_t)(zend_intptr_t)ZEND_CALL_VAR_NUM(NULL, op_array->last_var + brk_opline->op1.var);
+							ZEND_VM_SET_OPCODE_HANDLER(pass2_opline - free_vars);
+						}
+						free_vars--;
+					} else if (brk_opline->opcode == ZEND_FE_FREE) {
+						(pass2_opline - free_vars)->opcode = ZEND_FE_FREE;
+						(pass2_opline - free_vars)->op1_type = brk_opline->op1_type;
+						if (op_array->fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK) {
+							(pass2_opline - free_vars)->op1.var = brk_opline->op1.var;
+						} else {
+							(pass2_opline - free_vars)->op1.var = (uint32_t)(zend_intptr_t)ZEND_CALL_VAR_NUM(NULL, op_array->last_var + brk_opline->op1.var);
+							ZEND_VM_SET_OPCODE_HANDLER(pass2_opline - free_vars);
+						}
+						free_vars--;
 					}
-					free_vars--;
 				}
 				current = CG(context).brk_cont_array[current].parent;
 			}
@@ -4768,6 +4801,14 @@ void zend_compile_func_decl(znode *result, zend_ast *ast) /* {{{ */
 		opline_ext->lineno = decl->start_lineno;
 	}
 
+	{
+		/* Push a separator to the loop variable stack */
+		znode dummy_var;
+		dummy_var.op_type = IS_UNUSED;
+
+		zend_stack_push(&CG(loop_var_stack), (void *) &dummy_var);
+	}
+
 	zend_compile_params(params_ast, return_type_ast);
 	if (uses_ast) {
 		zend_compile_closure_uses(uses_ast);
@@ -4785,6 +4826,9 @@ void zend_compile_func_decl(znode *result, zend_ast *ast) /* {{{ */
 	pass_two(CG(active_op_array));
 	zend_oparray_context_end(&orig_oparray_context);
 
+	/* Pop the loop variable stack separator */
+	zend_stack_del_top(&CG(loop_var_stack));
+
 	CG(active_op_array) = orig_op_array;
 }
 /* }}} */
diff --git a/Zend/zend_compile.h b/Zend/zend_compile.h
index 3f9c091061..993a19fb6b 100644
--- a/Zend/zend_compile.h
+++ b/Zend/zend_compile.h
@@ -110,10 +110,10 @@ typedef struct _zend_declarables {
 } zend_declarables;
 
 typedef struct _zend_brk_cont_element {
+	int start;
 	int cont;
 	int brk;
 	int parent;
-	znode loop_var;
 } zend_brk_cont_element;
 
 typedef struct _zend_label {
diff --git a/Zend/zend_globals.h b/Zend/zend_globals.h
index 780007174e..28487a2a4a 100644
--- a/Zend/zend_globals.h
+++ b/Zend/zend_globals.h
@@ -68,6 +68,8 @@ typedef struct _zend_ini_entry zend_ini_entry;
 
 
 struct _zend_compiler_globals {
+	zend_stack loop_var_stack;
+
 	zend_class_entry *active_class_entry;
 
 	zend_string *compiled_filename;