lldb/docs/dil-expr-lang.ebnf

(* Data Inspection Language (DIL) definition - LLDB Debug Expressions *)

(* This is currently a subset of the final DIL Language, matching the current
   DIL implementation. *)

expression = assignment_expression ;

assignment_expression = conditional_expression
                      | logical_or_expression assignment_operator pure_expression ;

assignment_operator = "="
                    | "+="
                    | "-=" ;

pure_expression = conditional_expression ;

conditional_expression = logical_or_expression
                       | logical_or_expression "?" pure_expression ":" pure_expression ;

logical_or_expression = logical_and_expression {"||" logical_and_expression} ;

logical_and_expression = inclusive_or_expression {"&&" inclusive_or_expression} ;

inclusive_or_expression = exclusive_or_expression {"|" exclusive_or_expression} ;

exclusive_or_expression = and_expression {"^" and_expression} ;

and_expression = equality_expression {"&" equality_expression} ;

equality_expression = relational_expression {"==" relational_expression}
                    | relational_expression {"!=" relational_expression} ;

relational_expression = shift_expression {"<" shift_expression}
                      | shift_expression {">" shift_expression}
                      | shift_expression {"<=" shift_expression}
                      | shift_expression {">=" shift_expression} ;

shift_expression = additive_expression {"<<" additive_expression}
                 | additive_expression {">>" additive_expression} ;

additive_expression = multiplicative_expression {"+" multiplicative_expression}
                    | multiplicative_expression {"-" multiplicative_expression} ;

multiplicative_expression = cast_expression {"*" cast_expression}
                          | cast_expression {"/" cast_expression}
                          | cast_expression {"%" cast_expression} ;

cast_expression = unary_expression
                | "(" type_id ")" cast_expression ;

unary_expression = postfix_expression
                 | unary_operator cast_expression ;

unary_operator = "*" | "&" | "+" | "-" | "~" | "!" ;

postfix_expression = primary_expression
                   | postfix_expression "[" pure_expression "]"
                   | postfix_expression "[" pure_expression ":" pure_expression "]"
                   | postfix_expression "." id_expression
                   | postfix_expression "->" id_expression ;

primary_expression = numeric_literal
                   | boolean_literal
                   | id_expression
                   | "(" pure_expression ")"
                   | "sizeof" "(" pure_expression ")"
                   | "sizeof" "(" type_id ")" ;

id_expression = unqualified_id
              | qualified_id
              | register
              | null_pointer ;

unqualified_id = identifier ;

qualified_id = ["::"] [nested_name_specifier] unqualified_id
             | ["::"] identifier ;

identifier = ? C99 Identifier ? ;

numeric_literal = ? Integer constant: hexademical, decimal, octal, binary ?
                | ? Floating constant ? ;

boolean_literal = "true" | "false" ;

null_pointer = "nullptr" ;

register = "$" ? Register name ? ;

nested_name_specifier = type_name "::"
                      | namespace_name '::'
                      | nested_name_specifier identifier "::" ;

type_id = type_specifier_seq [abstract_declarator] ;

type_specifier_seq = type_specifier [type_specifier];

type_specifier = ["::"] [nested_name_specifier] type_name
               | builtin_typename ;

nested_name_specifier = type_name "::"
                      | namespace_name "::"
                      | nested_name_specifier identifier "::" ;

abstract_declarator = ptr_operator [abstract_declarator] ;

ptr_operator = "*"
             | "&";

type_name = class_name
          | enum_name
          | typedef_name;

builtin_typename = identifier_seq;

class_name = identifier ;

enum_name = identifier ;

typedef_name = identifier ;

namespace_name = identifier ;

identifier_seq = identifier
               | identifier identifier_seq;