Fix bug #77966: Cannot alias a method named "namespace"

This is a bit tricky: In this cases we have "namespace as", which
means that we will only recognize "namespace" as an identifier when
the lookahead token is already at the "as". This means that
zend_lex_tstring picks up the wrong identifier.

We solve this by actually assigning the identifier as the semantic
value on the parser stack -- as in almost all cases we will not
actually need the identifier, this is just an (offset, size)
reference, not a copy of the string.

Additionally, we need to teach the lexer feedback mechanism used
by tokenizer TOKEN_PARSE mode to apply feedback to something
other than the very last token. To that purpose we pass through
the token text and check the tokens in reverse order to find the
right one.

Closes GH-5668.

Author: nikic

NEWS

@@ -29,6 +29,7 @@ PHP                                                                        NEWS
     extensions). (cmb)
   . Implemented FR #72089 (require() throws fatal error instead of exception).
     (Nikita)
+  . Fixed bug #77966 (Cannot alias a method named "namespace"). (Nikita)
 
 - BZ2:
   . Fixed bug #71263 (fread() does not report bzip2.decompress errors). (cmb)

Zend/tests/bug77966.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Bug #77966: Cannot alias a method named "namespace"
+--FILE--
+<?php
+
+trait A {
+    function namespace() {
+        echo "Called\n";
+    }
+}
+
+class C {
+    use A {
+        namespace as bar;
+    }
+}
+
+$c = new C;
+$c->bar();
+$c->namespace();
+
+?>
+--EXPECT--
+Called
+Called

Zend/zend_compile.c

@@ -653,7 +653,7 @@ static int zend_add_const_name_literal(zend_string *name, zend_bool unqualified)
 void zend_stop_lexing(void)
 {
 	if (LANG_SCNG(on_event)) {
-		LANG_SCNG(on_event)(ON_STOP, END, 0, LANG_SCNG(on_event_context));
+		LANG_SCNG(on_event)(ON_STOP, END, 0, NULL, 0, LANG_SCNG(on_event_context));
 	}
 
 	LANG_SCNG(yy_cursor) = LANG_SCNG(yy_limit);

Zend/zend_compile.h

@@ -117,11 +117,17 @@ typedef struct _zend_file_context {
 	HashTable seen_symbols;
 } zend_file_context;
 
+typedef struct {
+	uint32_t offset;
+	uint32_t len;
+} zend_lexer_ident_ref;
+
 typedef union _zend_parser_stack_elem {
 	zend_ast *ast;
 	zend_string *str;
 	zend_ulong num;
 	unsigned char *ptr;
+	zend_lexer_ident_ref ident;
 } zend_parser_stack_elem;
 
 void zend_compile_top_stmt(zend_ast *ast);

Zend/zend_globals.h

@@ -311,7 +311,9 @@ struct _zend_php_scanner_globals {
 	int scanned_string_len;
 
 	/* hooks */
-	void (*on_event)(zend_php_scanner_event event, int token, int line, void *context);
+	void (*on_event)(
+		zend_php_scanner_event event, int token, int line,
+		const char *text, size_t length, void *context);
 	void *on_event_context;
 };
 

Zend/zend_language_parser.y

@@ -96,18 +96,84 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token <ast> T_STRING_VARNAME "variable name (T_STRING_VARNAME)"
 %token <ast> T_NUM_STRING "number (T_NUM_STRING)"
 
+%token <ident> T_INCLUDE       "include (T_INCLUDE)"
+%token <ident> T_INCLUDE_ONCE  "include_once (T_INCLUDE_ONCE)"
+%token <ident> T_EVAL          "eval (T_EVAL)"
+%token <ident> T_REQUIRE       "require (T_REQUIRE)"
+%token <ident> T_REQUIRE_ONCE  "require_once (T_REQUIRE_ONCE)"
+%token <ident> T_LOGICAL_OR    "or (T_LOGICAL_OR)"
+%token <ident> T_LOGICAL_XOR   "xor (T_LOGICAL_XOR)"
+%token <ident> T_LOGICAL_AND   "and (T_LOGICAL_AND)"
+%token <ident> T_PRINT         "print (T_PRINT)"
+%token <ident> T_YIELD         "yield (T_YIELD)"
+%token <ident> T_YIELD_FROM    "yield from (T_YIELD_FROM)"
+%token <ident> T_INSTANCEOF    "instanceof (T_INSTANCEOF)"
+%token <ident> T_NEW           "new (T_NEW)"
+%token <ident> T_CLONE         "clone (T_CLONE)"
+%token <ident> T_EXIT          "exit (T_EXIT)"
+%token <ident> T_IF            "if (T_IF)"
+%token <ident> T_ELSEIF        "elseif (T_ELSEIF)"
+%token <ident> T_ELSE          "else (T_ELSE)"
+%token <ident> T_ENDIF         "endif (T_ENDIF)"
+%token <ident> T_ECHO          "echo (T_ECHO)"
+%token <ident> T_DO            "do (T_DO)"
+%token <ident> T_WHILE         "while (T_WHILE)"
+%token <ident> T_ENDWHILE      "endwhile (T_ENDWHILE)"
+%token <ident> T_FOR           "for (T_FOR)"
+%token <ident> T_ENDFOR        "endfor (T_ENDFOR)"
+%token <ident> T_FOREACH       "foreach (T_FOREACH)"
+%token <ident> T_ENDFOREACH    "endforeach (T_ENDFOREACH)"
+%token <ident> T_DECLARE       "declare (T_DECLARE)"
+%token <ident> T_ENDDECLARE    "enddeclare (T_ENDDECLARE)"
+%token <ident> T_AS            "as (T_AS)"
+%token <ident> T_SWITCH        "switch (T_SWITCH)"
+%token <ident> T_ENDSWITCH     "endswitch (T_ENDSWITCH)"
+%token <ident> T_CASE          "case (T_CASE)"
+%token <ident> T_DEFAULT       "default (T_DEFAULT)"
+%token <ident> T_BREAK         "break (T_BREAK)"
+%token <ident> T_CONTINUE      "continue (T_CONTINUE)"
+%token <ident> T_GOTO          "goto (T_GOTO)"
+%token <ident> T_FUNCTION      "function (T_FUNCTION)"
+%token <ident> T_FN            "fn (T_FN)"
+%token <ident> T_CONST         "const (T_CONST)"
+%token <ident> T_RETURN        "return (T_RETURN)"
+%token <ident> T_TRY           "try (T_TRY)"
+%token <ident> T_CATCH         "catch (T_CATCH)"
+%token <ident> T_FINALLY       "finally (T_FINALLY)"
+%token <ident> T_THROW         "throw (T_THROW)"
+%token <ident> T_USE           "use (T_USE)"
+%token <ident> T_INSTEADOF     "insteadof (T_INSTEADOF)"
+%token <ident> T_GLOBAL        "global (T_GLOBAL)"
+%token <ident> T_STATIC        "static (T_STATIC)"
+%token <ident> T_ABSTRACT      "abstract (T_ABSTRACT)"
+%token <ident> T_FINAL         "final (T_FINAL)"
+%token <ident> T_PRIVATE       "private (T_PRIVATE)"
+%token <ident> T_PROTECTED     "protected (T_PROTECTED)"
+%token <ident> T_PUBLIC        "public (T_PUBLIC)"
+%token <ident> T_VAR           "var (T_VAR)"
+%token <ident> T_UNSET         "unset (T_UNSET)"
+%token <ident> T_ISSET         "isset (T_ISSET)"
+%token <ident> T_EMPTY         "empty (T_EMPTY)"
+%token <ident> T_HALT_COMPILER "__halt_compiler (T_HALT_COMPILER)"
+%token <ident> T_CLASS         "class (T_CLASS)"
+%token <ident> T_TRAIT         "trait (T_TRAIT)"
+%token <ident> T_INTERFACE     "interface (T_INTERFACE)"
+%token <ident> T_EXTENDS       "extends (T_EXTENDS)"
+%token <ident> T_IMPLEMENTS    "implements (T_IMPLEMENTS)"
+%token <ident> T_NAMESPACE     "namespace (T_NAMESPACE)"
+%token <ident> T_LIST            "list (T_LIST)"
+%token <ident> T_ARRAY           "array (T_ARRAY)"
+%token <ident> T_CALLABLE        "callable (T_CALLABLE)"
+%token <ident> T_LINE            "__LINE__ (T_LINE)"
+%token <ident> T_FILE            "__FILE__ (T_FILE)"
+%token <ident> T_DIR             "__DIR__ (T_DIR)"
+%token <ident> T_CLASS_C         "__CLASS__ (T_CLASS_C)"
+%token <ident> T_TRAIT_C         "__TRAIT__ (T_TRAIT_C)"
+%token <ident> T_METHOD_C        "__METHOD__ (T_METHOD_C)"
+%token <ident> T_FUNC_C          "__FUNCTION__ (T_FUNC_C)"
+%token <ident> T_NS_C            "__NAMESPACE__ (T_NS_C)"
+
 %token END 0 "end of file"
-%token T_INCLUDE      "include (T_INCLUDE)"
-%token T_INCLUDE_ONCE "include_once (T_INCLUDE_ONCE)"
-%token T_EVAL         "eval (T_EVAL)"
-%token T_REQUIRE      "require (T_REQUIRE)"
-%token T_REQUIRE_ONCE "require_once (T_REQUIRE_ONCE)"
-%token T_LOGICAL_OR   "or (T_LOGICAL_OR)"
-%token T_LOGICAL_XOR  "xor (T_LOGICAL_XOR)"
-%token T_LOGICAL_AND  "and (T_LOGICAL_AND)"
-%token T_PRINT        "print (T_PRINT)"
-%token T_YIELD        "yield (T_YIELD)"
-%token T_YIELD_FROM   "yield from (T_YIELD_FROM)"
 %token T_PLUS_EQUAL   "+= (T_PLUS_EQUAL)"
 %token T_MINUS_EQUAL  "-= (T_MINUS_EQUAL)"
 %token T_MUL_EQUAL    "*= (T_MUL_EQUAL)"
@@ -131,7 +197,6 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token T_SPACESHIP "<=> (T_SPACESHIP)"
 %token T_SL "<< (T_SL)"
 %token T_SR ">> (T_SR)"
-%token T_INSTANCEOF  "instanceof (T_INSTANCEOF)"
 %token T_INC "++ (T_INC)"
 %token T_DEC "-- (T_DEC)"
 %token T_INT_CAST    "(int) (T_INT_CAST)"
@@ -141,70 +206,8 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token T_OBJECT_CAST "(object) (T_OBJECT_CAST)"
 %token T_BOOL_CAST   "(bool) (T_BOOL_CAST)"
 %token T_UNSET_CAST  "(unset) (T_UNSET_CAST)"
-%token T_NEW       "new (T_NEW)"
-%token T_CLONE     "clone (T_CLONE)"
-%token T_EXIT      "exit (T_EXIT)"
-%token T_IF        "if (T_IF)"
-%token T_ELSEIF    "elseif (T_ELSEIF)"
-%token T_ELSE      "else (T_ELSE)"
-%token T_ENDIF     "endif (T_ENDIF)"
-%token T_ECHO       "echo (T_ECHO)"
-%token T_DO         "do (T_DO)"
-%token T_WHILE      "while (T_WHILE)"
-%token T_ENDWHILE   "endwhile (T_ENDWHILE)"
-%token T_FOR        "for (T_FOR)"
-%token T_ENDFOR     "endfor (T_ENDFOR)"
-%token T_FOREACH    "foreach (T_FOREACH)"
-%token T_ENDFOREACH "endforeach (T_ENDFOREACH)"
-%token T_DECLARE    "declare (T_DECLARE)"
-%token T_ENDDECLARE "enddeclare (T_ENDDECLARE)"
-%token T_AS         "as (T_AS)"
-%token T_SWITCH     "switch (T_SWITCH)"
-%token T_ENDSWITCH  "endswitch (T_ENDSWITCH)"
-%token T_CASE       "case (T_CASE)"
-%token T_DEFAULT    "default (T_DEFAULT)"
-%token T_BREAK      "break (T_BREAK)"
-%token T_CONTINUE   "continue (T_CONTINUE)"
-%token T_GOTO       "goto (T_GOTO)"
-%token T_FUNCTION   "function (T_FUNCTION)"
-%token T_FN         "fn (T_FN)"
-%token T_CONST      "const (T_CONST)"
-%token T_RETURN     "return (T_RETURN)"
-%token T_TRY        "try (T_TRY)"
-%token T_CATCH      "catch (T_CATCH)"
-%token T_FINALLY    "finally (T_FINALLY)"
-%token T_THROW      "throw (T_THROW)"
-%token T_USE        "use (T_USE)"
-%token T_INSTEADOF  "insteadof (T_INSTEADOF)"
-%token T_GLOBAL     "global (T_GLOBAL)"
-%token T_STATIC     "static (T_STATIC)"
-%token T_ABSTRACT   "abstract (T_ABSTRACT)"
-%token T_FINAL      "final (T_FINAL)"
-%token T_PRIVATE    "private (T_PRIVATE)"
-%token T_PROTECTED  "protected (T_PROTECTED)"
-%token T_PUBLIC     "public (T_PUBLIC)"
-%token T_VAR        "var (T_VAR)"
-%token T_UNSET      "unset (T_UNSET)"
-%token T_ISSET      "isset (T_ISSET)"
-%token T_EMPTY      "empty (T_EMPTY)"
-%token T_HALT_COMPILER "__halt_compiler (T_HALT_COMPILER)"
-%token T_CLASS      "class (T_CLASS)"
-%token T_TRAIT      "trait (T_TRAIT)"
-%token T_INTERFACE  "interface (T_INTERFACE)"
-%token T_EXTENDS    "extends (T_EXTENDS)"
-%token T_IMPLEMENTS "implements (T_IMPLEMENTS)"
 %token T_OBJECT_OPERATOR "-> (T_OBJECT_OPERATOR)"
 %token T_DOUBLE_ARROW    "=> (T_DOUBLE_ARROW)"
-%token T_LIST            "list (T_LIST)"
-%token T_ARRAY           "array (T_ARRAY)"
-%token T_CALLABLE        "callable (T_CALLABLE)"
-%token T_LINE            "__LINE__ (T_LINE)"
-%token T_FILE            "__FILE__ (T_FILE)"
-%token T_DIR             "__DIR__ (T_DIR)"
-%token T_CLASS_C         "__CLASS__ (T_CLASS_C)"
-%token T_TRAIT_C         "__TRAIT__ (T_TRAIT_C)"
-%token T_METHOD_C        "__METHOD__ (T_METHOD_C)"
-%token T_FUNC_C          "__FUNCTION__ (T_FUNC_C)"
 %token T_COMMENT         "comment (T_COMMENT)"
 %token T_DOC_COMMENT     "doc comment (T_DOC_COMMENT)"
 %token T_OPEN_TAG        "open tag (T_OPEN_TAG)"
@@ -216,8 +219,6 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token T_DOLLAR_OPEN_CURLY_BRACES "${ (T_DOLLAR_OPEN_CURLY_BRACES)"
 %token T_CURLY_OPEN      "{$ (T_CURLY_OPEN)"
 %token T_PAAMAYIM_NEKUDOTAYIM ":: (T_PAAMAYIM_NEKUDOTAYIM)"
-%token T_NAMESPACE       "namespace (T_NAMESPACE)"
-%token T_NS_C            "__NAMESPACE__ (T_NS_C)"
 %token T_NS_SEPARATOR    "\\ (T_NS_SEPARATOR)"
 %token T_ELLIPSIS        "... (T_ELLIPSIS)"
 %token T_COALESCE        "?? (T_COALESCE)"
@@ -268,6 +269,8 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %type <ptr> backup_lex_pos
 %type <str> backup_doc_comment
 
+%type <ident> reserved_non_modifiers semi_reserved
+
 %% /* Rules */
 
 start:
@@ -293,7 +296,7 @@ identifier:
 		T_STRING { $$ = $1; }
 	| 	semi_reserved  {
 			zval zv;
-			zend_lex_tstring(&zv);
+			zend_lex_tstring(&zv, $1);
 			$$ = zend_ast_create_zval(&zv);
 		}
 ;
@@ -847,7 +850,8 @@ trait_alias:
 		trait_method_reference T_AS T_STRING
 			{ $$ = zend_ast_create(ZEND_AST_TRAIT_ALIAS, $1, $3); }
 	|	trait_method_reference T_AS reserved_non_modifiers
-			{ zval zv; zend_lex_tstring(&zv); $$ = zend_ast_create(ZEND_AST_TRAIT_ALIAS, $1, zend_ast_create_zval(&zv)); }
+			{ zval zv; zend_lex_tstring(&zv, $3);
+			  $$ = zend_ast_create(ZEND_AST_TRAIT_ALIAS, $1, zend_ast_create_zval(&zv)); }
 	|	trait_method_reference T_AS member_modifier identifier
 			{ $$ = zend_ast_create_ex(ZEND_AST_TRAIT_ALIAS, $3, $1, $4); }
 	|	trait_method_reference T_AS member_modifier

Zend/zend_language_scanner.h

@@ -50,7 +50,9 @@ typedef struct _zend_lex_state {
 	const zend_encoding *script_encoding;
 
 	/* hooks */
-	void (*on_event)(zend_php_scanner_event event, int token, int line, void *context);
+	void (*on_event)(
+		zend_php_scanner_event event, int token, int line,
+		const char *text, size_t length, void *context);
 	void *on_event_context;
 
 	zend_ast *ast;
@@ -76,7 +78,7 @@ ZEND_API void zend_restore_lexical_state(zend_lex_state *lex_state);
 ZEND_API int zend_prepare_string_for_scanning(zval *str, const char *filename);
 ZEND_API void zend_multibyte_yyinput_again(zend_encoding_filter old_input_filter, const zend_encoding *old_encoding);
 ZEND_API int zend_multibyte_set_filter(const zend_encoding *onetime_encoding);
-ZEND_API void zend_lex_tstring(zval *zv);
+ZEND_API void zend_lex_tstring(zval *zv, zend_lexer_ident_ref ident_ref);
 
 END_EXTERN_C()