Fix lexing of nested heredoc strings in token_get_all()

This fixes bug #60097.

Before two global variables CG(heredoc) and CG(heredoc_len) were used to
track the current heredoc label. In order to support nested heredoc
strings the *previous* heredoc label was assigned as the token value of
T_START_HEREDOC and the language_parser.y assigned that to CG(heredoc).

This created a dependency of the lexer on the parser. Thus the
token_get_all() function, which accesses the lexer directly without
also running the parser, was not able to tokenize nested heredoc strings
(and leaked memory). Same applies for the source-code highlighting
functions.

The new approach is to maintain a heredoc_label_stack in the lexer, which
contains all active heredoc labels.

As it is no longer required, T_START_HEREDOC and T_END_HEREDOC now don't
carry a token value anymore.

In order to make the work with zend_ptr_stack in this context more
convenient I added a new function zend_ptr_stack_top(), which retrieves the
top element of the stack (similar to zend_stack_top()).

1 files changed, 1 insertions, 3 deletions

diff --git a/Zend/zend_globals.h b/Zend/zend_globals.h
index dbbcf972a4..e5aba0df67 100644
--- a/Zend/zend_globals.h
+++ b/Zend/zend_globals.h
@@ -89,9 +89,6 @@ struct _zend_compiler_globals {
 
 	int zend_lineno;
 
-	char *heredoc;
-	int heredoc_len;
-
 	zend_op_array *active_op_array;
 
 	HashTable *function_table;	/* function symbol table */
@@ -297,6 +294,7 @@ struct _zend_php_scanner_globals {
 	unsigned char *yy_limit;
 	int yy_state;
 	zend_stack state_stack;
+	zend_ptr_stack heredoc_label_stack;
 	
 	/* original (unfiltered) script */
 	unsigned char *script_org;