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zend_language_scanner: Lex clone as identifier when followed by ( #18981

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zend_language_scanner: Lex clone as identifier when followed by ( #18981

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44 changes: 5 additions & 39 deletions Zend/zend_language_parser.y
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Original file line number Diff line number Diff line change
Expand Up @@ -259,7 +259,7 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
%type <ast> unprefixed_use_declarations const_decl inner_statement
%type <ast> expr optional_expr while_statement for_statement foreach_variable
%type <ast> foreach_statement declare_statement finally_statement unset_variable variable
%type <ast> extends_from parameter optional_type_without_static argument argument_no_expr global_var
%type <ast> extends_from parameter optional_type_without_static argument global_var
%type <ast> static_var class_statement trait_adaptation trait_precedence trait_alias
%type <ast> absolute_trait_method_reference trait_method_reference property echo_expr
%type <ast> new_dereferenceable new_non_dereferenceable anonymous_class class_name class_name_reference simple_variable
Expand Down Expand Up @@ -287,7 +287,7 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
%type <ast> enum_declaration_statement enum_backing_type enum_case enum_case_expr
%type <ast> function_name non_empty_member_modifiers
%type <ast> property_hook property_hook_list optional_property_hook_list hooked_property property_hook_body
%type <ast> optional_parameter_list clone_argument_list non_empty_clone_argument_list
%type <ast> optional_parameter_list

%type <num> returns_ref function fn is_reference is_variadic property_modifiers property_hook_modifiers
%type <num> method_modifiers class_const_modifiers member_modifier optional_cpp_modifiers
Expand Down Expand Up @@ -914,42 +914,13 @@ non_empty_argument_list:
{ $$ = zend_ast_list_add($1, $3); }
;

/* `clone_argument_list` is necessary to resolve a parser ambiguity (shift-reduce conflict)
* of `clone($expr)`, which could either be parsed as a function call with `$expr` as the first
* argument or as a use of the `clone` language construct with an expression with useless
* parenthesis. Both would be valid and result in the same AST / the same semantics.
* `clone_argument_list` is defined in a way that an `expr` in the first position needs to
* be followed by a `,` which is not valid syntax for a parenthesized `expr`, ensuring
* that calling `clone()` with a single unnamed parameter is handled by the language construct
* syntax.
*/
clone_argument_list:
'(' ')' { $$ = zend_ast_create_list(0, ZEND_AST_ARG_LIST); }
| '(' non_empty_clone_argument_list possible_comma ')' { $$ = $2; }
| '(' expr ',' ')' { $$ = zend_ast_create_list(1, ZEND_AST_ARG_LIST, $2); }
| '(' T_ELLIPSIS ')' { $$ = zend_ast_create_fcc(); }
;

non_empty_clone_argument_list:
expr ',' argument
{ $$ = zend_ast_create_list(2, ZEND_AST_ARG_LIST, $1, $3); }
| argument_no_expr
{ $$ = zend_ast_create_list(1, ZEND_AST_ARG_LIST, $1); }
| non_empty_clone_argument_list ',' argument
{ $$ = zend_ast_list_add($1, $3); }
;

argument_no_expr:
identifier ':' expr
argument:
expr { $$ = $1; }
| identifier ':' expr
{ $$ = zend_ast_create(ZEND_AST_NAMED_ARG, $1, $3); }
| T_ELLIPSIS expr { $$ = zend_ast_create(ZEND_AST_UNPACK, $2); }
;

argument:
expr { $$ = $1; }
| argument_no_expr { $$ = $1; }
;

global_var_list:
global_var_list ',' global_var { $$ = zend_ast_list_add($1, $3); }
| global_var { $$ = zend_ast_create_list(1, ZEND_AST_STMT_LIST, $1); }
Expand Down Expand Up @@ -1257,11 +1228,6 @@ expr:
{ $$ = zend_ast_create(ZEND_AST_ASSIGN, $1, $3); }
| variable '=' ampersand variable
{ $$ = zend_ast_create(ZEND_AST_ASSIGN_REF, $1, $4); }
| T_CLONE clone_argument_list {
zend_ast *name = zend_ast_create_zval_from_str(ZSTR_KNOWN(ZEND_STR_CLONE));
name->attr = ZEND_NAME_FQ;
$$ = zend_ast_create(ZEND_AST_CALL, name, $2);
}
| T_CLONE expr {
zend_ast *name = zend_ast_create_zval_from_str(ZSTR_KNOWN(ZEND_STR_CLONE));
name->attr = ZEND_NAME_FQ;
Expand Down
5 changes: 5 additions & 0 deletions Zend/zend_language_scanner.l
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Expand Up @@ -1613,6 +1613,11 @@ OPTIONAL_WHITESPACE_OR_COMMENTS ({WHITESPACE}|{MULTI_LINE_COMMENT}|{SINGLE_LINE_
RETURN_TOKEN_WITH_IDENT(T_NEW);
}

<ST_IN_SCRIPTING>"clone"{OPTIONAL_WHITESPACE_OR_COMMENTS}"(" {
yyless(5);
RETURN_TOKEN_WITH_STR(T_NAME_FULLY_QUALIFIED, 0);
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Would lexing it as T_STRING instead work?
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That would work, but “require” a special case in the compiler to treat clone($x, $y) in a namespace as a fully-qualified call.
}

<ST_IN_SCRIPTING>"clone" {
RETURN_TOKEN_WITH_IDENT(T_CLONE);
}
Expand Down
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