From: Dmitry Stogov <dmitry@php.net>
Date: Fri, 3 Mar 2006 13:09:13 +0000 (+0000)
Subject: Added support for "continue" and "break" operators with labels. Each loop or switch... 
X-Git-Tag: RELEASE_1_2~22
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2a2050d4e38ae1a19975aecca788af225cd5a4f3;p=php

Added support for "continue" and "break" operators with labels. Each loop or switch statement can be marked by label and then it is possible to write "break <label>" instead of "break <number>".
---

diff --git a/NEWS b/NEWS
index 4b8bcbb44d..b20bac0b77 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,9 @@ PHP                                                                        NEWS
   for more details. (Dmitry)
 - Removed support for "continue" and "break" operators with non-constant
   operands. (Dmitry)
+- Added support for "continue" and "break" operators with labels. Each loop or
+  switch statement can be marked by label and then it is possible to write
+  "break <label>" instead of "break <number>". (Dmitry, Sara)
 - Changed __toString() behavior to call it in all necessary places
   (Marcus, Dmitry)
 - Changed "instanceof" and "catch" operators, is_a() and is_subclass_of()
diff --git a/Zend/tests/break_label01.phpt b/Zend/tests/break_label01.phpt
new file mode 100755
index 0000000000..20e1a5c4b7
--- /dev/null
+++ b/Zend/tests/break_label01.phpt
@@ -0,0 +1,56 @@
+--TEST--
+labeled break 01: Old style "break <number>"
+--FILE--
+<?php
+while (1) {
+	echo "1: ";
+	break 1;
+	echo "bug\n";
+}
+echo "ok\n";
+
+while (1) {
+	echo "2: ";
+	while (1) {
+		break 2;
+		echo "bug\n";
+	}
+	echo "bug\n";
+}
+echo "ok\n";
+
+while (1) {
+	echo "3: ";
+	while (1) {
+		break 1;
+		echo "bug\n";
+	}
+	break 1;
+	echo "bug\n";
+}
+echo "ok\n";
+
+while (1) {
+	echo "4: ";
+	switch (1) {
+		case 1:
+			break 2;
+			echo "bug\n";
+	}
+	echo "bug\n";
+}
+echo "ok\n";
+
+while (1) {
+	while (1) {
+		break 3;
+	}
+}
+?>
+--EXPECTF--
+1: ok
+2: ok
+3: ok
+4: ok
+
+Fatal error: Cannot break/continue 3 levels in %sbreak_label01.php on line %d
diff --git a/Zend/tests/break_label02.phpt b/Zend/tests/break_label02.phpt
new file mode 100755
index 0000000000..7c9a673452
--- /dev/null
+++ b/Zend/tests/break_label02.phpt
@@ -0,0 +1,66 @@
+--TEST--
+labeled break 02: New style "break <label>"
+--FILE--
+<?php
+L1: while (1) {
+	echo "1: ";
+	break L1;
+	echo "bug\n";
+}
+
+echo "ok\n";
+
+L2: while (1) {
+	echo "2: ";
+	while (1) {
+		break L2;
+		echo "bug\n";
+	}
+	echo "bug\n";
+}
+
+echo "ok\n";
+
+L3: while (1) {
+	echo "3: ";
+	L4: while (1) {
+		break L4;
+		echo "bug\n";
+	}
+	break L3;
+	echo "bug\n";
+}
+
+echo "ok\n";
+
+L5: while (1) {
+	echo "4: ";
+	switch (1) {
+		case 1:
+			break L5;
+			echo "bug\n";
+	}
+	echo "bug\n";
+}
+
+echo "ok\n";
+
+L6: while (1) {
+	echo "5: ";
+	L7: switch (1) {
+		case 1:
+			break L7;
+			echo "bug\n";
+	}
+	break L6;
+	echo "bug\n";
+}
+
+echo "ok\n";
+?>
+--EXPECT--
+1: ok
+2: ok
+3: ok
+4: ok
+5: ok
diff --git a/Zend/tests/break_label03.phpt b/Zend/tests/break_label03.phpt
new file mode 100755
index 0000000000..b3de5498fd
--- /dev/null
+++ b/Zend/tests/break_label03.phpt
@@ -0,0 +1,11 @@
+--TEST--
+labeled break 03: Undefined label
+--FILE--
+<?php
+echo "bug\n";
+L1: while (1) {
+	break L2;
+}
+?>
+--EXPECTF--
+Fatal error: break to undefined label 'L2' in %sbreak_label03.php on line %d
diff --git a/Zend/tests/break_label04.phpt b/Zend/tests/break_label04.phpt
new file mode 100755
index 0000000000..b947d0f9f0
--- /dev/null
+++ b/Zend/tests/break_label04.phpt
@@ -0,0 +1,14 @@
+--TEST--
+labeled break 04: Invalid label (another loop)
+--FILE--
+<?php
+echo "bug\n";
+L1: while (1) {
+	break;
+}
+L2: while (1) {
+	break L1;
+}
+?>
+--EXPECTF--
+Fatal error: break to label 'L1', that doesn't mark outer loop in %sbreak_label04.php on line %d
diff --git a/Zend/tests/break_label05.phpt b/Zend/tests/break_label05.phpt
new file mode 100755
index 0000000000..98e72092af
--- /dev/null
+++ b/Zend/tests/break_label05.phpt
@@ -0,0 +1,12 @@
+--TEST--
+labeled break 05: Invalid label (non loop)
+--FILE--
+<?php
+L1:
+echo "bug\n";
+while (1) {
+	break L1;
+}
+?>
+--EXPECTF--
+Fatal error: break to label 'L1', that doesn't mark outer loop in %sbreak_label05.php on line %d
diff --git a/Zend/tests/break_label06.phpt b/Zend/tests/break_label06.phpt
new file mode 100755
index 0000000000..d2b3759e60
--- /dev/null
+++ b/Zend/tests/break_label06.phpt
@@ -0,0 +1,12 @@
+--TEST--
+labeled break 06: Invalid label (non declared yet)
+--FILE--
+<?php
+echo "bug\n";
+while (1) {	
+	break L1;
+}
+L1:
+?>
+--EXPECTF--
+Fatal error: break to undefined label 'L1' in %sbreak_label06.php on line %d
diff --git a/Zend/tests/break_label07.phpt b/Zend/tests/break_label07.phpt
new file mode 100755
index 0000000000..eb7d40a32e
--- /dev/null
+++ b/Zend/tests/break_label07.phpt
@@ -0,0 +1,17 @@
+--TEST--
+labeled break 07: Label redefinition 
+--FILE--
+<?php
+echo "bug\n";
+L1: while (1) {	
+	L2: while (1) {	
+		break L1;
+	}
+}
+L3: while (1) {	
+	L1: while (1) {	
+		break L3;
+	}
+}
+--EXPECTF--
+Fatal error: Label 'L1' already defined in %sbreak_label07.php on line %d
diff --git a/Zend/tests/break_label08.inc b/Zend/tests/break_label08.inc
new file mode 100755
index 0000000000..f424fb068f
--- /dev/null
+++ b/Zend/tests/break_label08.inc
@@ -0,0 +1,11 @@
+<?php
+L1: while (1) {	
+	echo "2: ";
+	L2: while (1) {	
+		break L1;
+		echo "bug\n";
+	}
+	echo "bug\n";
+}
+echo "ok\n";
+?>
diff --git a/Zend/tests/break_label08.phpt b/Zend/tests/break_label08.phpt
new file mode 100755
index 0000000000..2aceb89fc8
--- /dev/null
+++ b/Zend/tests/break_label08.phpt
@@ -0,0 +1,18 @@
+--TEST--
+labeled break 08: Use the same <label> in different files
+--FILE--
+<?php
+L1: while (1) {	
+	echo "1: ";
+	L2: while (1) {	
+		break L1;
+		echo "bug\n";
+	}
+	echo "bug\n";
+}
+echo "ok\n";
+include(dirname(__FILE__)."/break_label08.inc");
+?>
+--EXPECT--
+1: ok
+2: ok
diff --git a/Zend/tests/break_label09.phpt b/Zend/tests/break_label09.phpt
new file mode 100755
index 0000000000..f5b4758fa6
--- /dev/null
+++ b/Zend/tests/break_label09.phpt
@@ -0,0 +1,26 @@
+--TEST--
+labeled break 09: Use the same <label> name in several copies of one file
+--FILE--
+<?php
+if (isset($n)) {
+	++$n;
+} else {
+	$n = 1;
+}
+L1: while (1) {	
+	echo "$n: ";
+	L2: while (1) {	
+		break L1;
+		echo "bug\n";
+	}
+	echo "bug\n";
+}
+echo "ok\n";
+if ($n < 3) {
+	include(__FILE__);
+}
+?>
+--EXPECTF--
+1: ok
+2: ok
+3: ok
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 164599b94a..08a90cc85a 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -148,6 +148,9 @@ void zend_init_compiler_data_structures(TSRMLS_D)
 	CG(start_lineno) = 0;
 	init_compiler_declarables(TSRMLS_C);
 	zend_hash_apply(CG(auto_globals), (apply_func_t) zend_auto_global_arm TSRMLS_CC);
+	zend_stack_init(&CG(labels_stack));
+	CG(labels) = NULL;
+	CG(last_label) = NULL;
 }
 
 
@@ -174,6 +177,7 @@ void shutdown_compiler(TSRMLS_D)
 	zend_hash_destroy(&CG(script_encodings_table));
 	zend_hash_destroy(&CG(filenames_table));
 	zend_llist_destroy(&CG(open_files));
+	zend_stack_destroy(&CG(labels_stack));
 }
 
 
@@ -675,6 +679,10 @@ static inline void do_begin_loop(TSRMLS_D)
 	CG(active_op_array)->current_brk_cont = CG(active_op_array)->last_brk_cont;
 	brk_cont_element = get_next_brk_cont_element(CG(active_op_array));
 	brk_cont_element->parent = parent;
+	if (CG(last_label)) {
+		CG(last_label)->loop = CG(active_op_array)->current_brk_cont;
+		CG(last_label) = NULL;
+	}
 }
 
 
@@ -1241,6 +1249,10 @@ void zend_do_begin_function_declaration(znode *function_token, znode *function_n
 		CG(doc_comment) = NULL;
 		CG(doc_comment_len) = 0;
 	}
+
+	zend_stack_push(&CG(labels_stack), (void *) &CG(labels), sizeof(HashTable*));
+	CG(labels) = NULL;
+	CG(last_label) = NULL;
 }
 
 void zend_do_handle_exception(TSRMLS_D)
@@ -1250,6 +1262,21 @@ void zend_do_handle_exception(TSRMLS_D)
 	opline->opcode = ZEND_HANDLE_EXCEPTION;
 	SET_UNUSED(opline->op1);
 	SET_UNUSED(opline->op2);
+
+	if (CG(labels)) {
+		zend_hash_destroy(CG(labels));
+		FREE_HASHTABLE(CG(labels));
+	}
+	if (!zend_stack_is_empty(&CG(labels_stack))) {
+		HashTable **pht;
+
+		zend_stack_top(&CG(labels_stack), (void**)&pht);
+		CG(labels) = *pht;
+		zend_stack_del_top(&CG(labels_stack));
+	} else {
+		CG(labels) = NULL;
+	}
+	CG(last_label) = NULL;
 }
 
 
@@ -2665,8 +2692,37 @@ void zend_do_brk_cont(zend_uchar op, znode *expr TSRMLS_DC)
 	if (expr) {
 		if (expr->op_type != IS_CONST) {
 			zend_error(E_COMPILE_ERROR, "'%s' operator with non-constant operand is no longer supported", op == ZEND_BRK ? "break" : "continue");
-		} else if (Z_TYPE(expr->u.constant) != IS_LONG || Z_LVAL(expr->u.constant) < 1) {
-			zend_error(E_COMPILE_ERROR, "'%s' operator accepts only positive numbers", op == ZEND_BRK ? "break" : "continue");
+		} else {
+			if (Z_TYPE(expr->u.constant) == IS_STRING ||
+			    Z_TYPE(expr->u.constant) == IS_UNICODE) {
+				zend_label *label;
+
+				if (CG(labels) == NULL ||
+				    zend_u_hash_find(CG(labels), Z_TYPE(expr->u.constant), Z_UNIVAL(expr->u.constant), Z_UNILEN(expr->u.constant)+1, (void**)&label) == FAILURE) {
+					zend_error(E_COMPILE_ERROR, "%s to undefined label '%R'", op == ZEND_BRK ? "break" : "continue", Z_TYPE(expr->u.constant), Z_UNIVAL(expr->u.constant));
+				}
+				
+				if (label->loop != -1) {
+					long distance = 1;
+					long current = CG(active_op_array)->current_brk_cont;
+
+					while (current != -1) {
+						if (label->loop == current) {
+							zval_dtor(&expr->u.constant);
+							Z_TYPE(expr->u.constant) = IS_LONG;
+							Z_LVAL(expr->u.constant) = distance;
+							break;
+						}
+						distance++;
+						current = CG(active_op_array)->brk_cont_array[current].parent;
+					}
+				}
+				if (Z_TYPE(expr->u.constant) != IS_LONG) {
+					zend_error(E_COMPILE_ERROR, "%s to label '%R', that doesn't mark outer loop", op == ZEND_BRK ? "break" : "continue", Z_TYPE(expr->u.constant), Z_UNIVAL(expr->u.constant));
+				}
+			} else if (Z_TYPE(expr->u.constant) != IS_LONG || Z_LVAL(expr->u.constant) < 1) {
+				zend_error(E_COMPILE_ERROR, "'%s' operator accepts only positive numbers and labels", op == ZEND_BRK ? "break" : "continue");
+			}
 		}
 		opline->op2 = *expr;
 	} else {
@@ -4315,6 +4371,30 @@ void zend_do_normalization(znode *result, znode *str TSRMLS_DC)
 	*result = opline->result;
 }
 
+void zend_do_label(znode *label TSRMLS_DC)
+{
+	zend_op_array *oparray = CG(active_op_array);
+	zend_label dest;
+
+	if (!CG(labels)) {
+		ALLOC_HASHTABLE(CG(labels));
+		zend_hash_init(CG(labels), 4, NULL, NULL, 0);
+	}
+
+	dest.brk_cont = oparray->current_brk_cont;
+	dest.loop = -1;
+	dest.opline_num = get_next_op_number(oparray);
+
+	if (zend_u_hash_add(CG(labels), Z_TYPE(label->u.constant), Z_UNIVAL(label->u.constant),
+					Z_UNILEN(label->u.constant) + 1, (void**)&dest, sizeof(zend_label), (void**)&CG(last_label)) == FAILURE) {
+		CG(last_label) = NULL;
+		zend_error(E_COMPILE_ERROR, "Label '%R' already defined", Z_TYPE(label->u.constant), Z_UNIVAL(label->u.constant));
+	}
+
+	/* Done with label now */
+	zval_dtor(&label->u.constant);
+}
+
 /*
  * Local variables:
  * tab-width: 4
diff --git a/Zend/zend_compile.h b/Zend/zend_compile.h
index cb5d5bf9c2..51da2581c5 100644
--- a/Zend/zend_compile.h
+++ b/Zend/zend_compile.h
@@ -94,6 +94,11 @@ typedef struct _zend_brk_cont_element {
 	int parent;
 } zend_brk_cont_element;
 
+typedef struct _zend_label {
+	int brk_cont;
+	int loop;
+	zend_uint opline_num;
+} zend_label;
 
 typedef struct _zend_try_catch_element {
 	zend_uint try_op;
@@ -513,6 +518,8 @@ ZEND_API void function_add_ref(zend_function *function TSRMLS_DC);
 
 void zend_do_normalization(znode *result, znode *str TSRMLS_DC);
 
+void zend_do_label(znode *label TSRMLS_DC);
+
 #define INITIAL_OP_ARRAY_SIZE 64
 
 
diff --git a/Zend/zend_globals.h b/Zend/zend_globals.h
index 6af32473b1..a397c65974 100644
--- a/Zend/zend_globals.h
+++ b/Zend/zend_globals.h
@@ -136,6 +136,10 @@ struct _zend_compiler_globals {
 	HashTable script_encodings_table;
 	char *script_encoding;
 
+	HashTable *labels;
+	zend_label *last_label;
+	zend_stack labels_stack;
+
 #ifdef ZTS
 	HashTable **static_members;
 	int last_static_member;
diff --git a/Zend/zend_language_parser.y b/Zend/zend_language_parser.y
index a0addb86dc..69ea6fb657 100644
--- a/Zend/zend_language_parser.y
+++ b/Zend/zend_language_parser.y
@@ -183,11 +183,12 @@ inner_statement:
 
 
 statement:
-		unticked_statement { zend_do_ticks(TSRMLS_C); }
+		unticked_statement { CG(last_label) = NULL; zend_do_ticks(TSRMLS_C); }
+	|	T_STRING ':' { zend_do_label(&$1 TSRMLS_CC); }
 ;
 
 unticked_statement:
-		'{' inner_statement_list '}'
+		'{' { CG(last_label) = NULL; } inner_statement_list '}'
 	|	T_IF '(' expr ')' { zend_do_if_cond(&$3, &$4 TSRMLS_CC); } statement { zend_do_if_after_statement(&$4, 1 TSRMLS_CC); } elseif_list else_single { zend_do_if_end(TSRMLS_C); }
 	|	T_IF '(' expr ')' ':' { zend_do_if_cond(&$3, &$4 TSRMLS_CC); } inner_statement_list { zend_do_if_after_statement(&$4, 1 TSRMLS_CC); } new_elseif_list new_else_single T_ENDIF ';' { zend_do_if_end(TSRMLS_C); }
 	|	T_WHILE '(' { $1.u.opline_num = get_next_op_number(CG(active_op_array));  } expr  ')' { zend_do_while_cond(&$4, &$5 TSRMLS_CC); } while_statement { zend_do_while_end(&$1, &$5 TSRMLS_CC); }
@@ -203,9 +204,11 @@ unticked_statement:
 			for_statement { zend_do_for_end(&$7 TSRMLS_CC); }
 	|	T_SWITCH '(' expr ')'	{ zend_do_switch_cond(&$3 TSRMLS_CC); } switch_case_list { zend_do_switch_end(&$6 TSRMLS_CC); }
 	|	T_BREAK ';'				{ zend_do_brk_cont(ZEND_BRK, NULL TSRMLS_CC); }
-	|	T_BREAK expr ';'		{ zend_do_brk_cont(ZEND_BRK, &$2 TSRMLS_CC); }
+	|	T_BREAK T_LNUMBER ';'		{ zend_do_brk_cont(ZEND_BRK, &$2 TSRMLS_CC); }
+	|	T_BREAK T_STRING ';'		{ zend_do_brk_cont(ZEND_BRK, &$2 TSRMLS_CC); }
 	|	T_CONTINUE ';'			{ zend_do_brk_cont(ZEND_CONT, NULL TSRMLS_CC); }
-	|	T_CONTINUE expr ';'		{ zend_do_brk_cont(ZEND_CONT, &$2 TSRMLS_CC); }
+	|	T_CONTINUE T_LNUMBER ';'		{ zend_do_brk_cont(ZEND_CONT, &$2 TSRMLS_CC); }
+	|	T_CONTINUE T_STRING ';'		{ zend_do_brk_cont(ZEND_CONT, &$2 TSRMLS_CC); }
 	|	T_RETURN ';'						{ zend_do_return(NULL, 0 TSRMLS_CC); }
 	|	T_RETURN expr_without_variable ';'	{ zend_do_return(&$2, 0 TSRMLS_CC); }
 	|	T_RETURN variable ';'				{ zend_do_return(&$2, 1 TSRMLS_CC); }