symbol¶

The symbols of ASR.

Declaration¶

Syntax¶

symbol
    = Program(symbol_table symtab, identifier name, identifier* dependencies, stmt* body, location start_name, location end_name)
    | Module(symbol_table symtab, identifier name, identifier? parent_module, identifier* dependencies, bool loaded_from_mod, bool intrinsic, bool has_submodules, location start_name, location end_name)
    | Function(symbol_table symtab, identifier name, ttype function_signature, identifier* dependencies, expr* args, stmt* body, expr? return_var, access access, bool deterministic, bool side_effect_free, string? module_file, location start_name, location end_name)
    | GenericProcedure(symbol_table parent_symtab, identifier name, symbol* procs, access access)
    | CustomOperator(symbol_table parent_symtab, identifier name, symbol* procs, access access)
    | ExternalSymbol(symbol_table parent_symtab, identifier name, symbol external, identifier module_name, identifier* scope_names, identifier original_name, access access)
    | Struct(symbol_table symtab, identifier name, ttype struct_signature, identifier* dependencies, identifier* members, identifier* member_functions, abi abi, access access, bool is_packed, bool is_abstract, bool is_sequence, call_arg* initializers, expr? alignment, symbol? parent, identifier* kind_params)
    | Enum(symbol_table symtab, identifier name, identifier* dependencies, identifier* members, abi abi, access access, enumtype enum_value_type, ttype type, symbol? parent)
    | Union(symbol_table symtab, identifier name, identifier* dependencies, identifier* members, abi abi, access access, call_arg* initializers, symbol? parent)
    | Variable(symbol_table parent_symtab, identifier name, identifier* dependencies, intent intent, expr? symbolic_value, expr? value, storage_type storage, ttype type, symbol? type_declaration, abi abi, access access, presence presence, bool value_attr, bool target_attr, bool contiguous_attr, string? bindc_name, bool is_volatile, bool is_protected, pass_attr pass_attr, identifier? self_argument, codimension* codims)
    | StructMethodDeclaration(symbol_table parent_symtab, identifier name, identifier? self_argument, identifier proc_name, symbol proc, abi abi, bool is_deferred, bool is_nopass)
    | AssociateBlock(symbol_table symtab, identifier name, stmt* body)
    | Block(symbol_table symtab, identifier name, stmt* body)
    | Requirement(symbol_table symtab, identifier name, identifier* args, require_instantiation* requires)
    | Template(symbol_table symtab, identifier name, identifier* args, require_instantiation* requires)
    | Namelist(symbol_table parent_symtab, identifier group_name, symbol* var_list)

Arguments¶

None.

Return values¶

None.

Description¶

A symbol is an entry of a symbol table. Every symbol carries its name, so that a pointer to one is enough to report what it is, and either a symtab it owns or the parent_symtab it is stored in; only one of the two is present, because the parent is reachable from a symbol table it owns.

The symbols divide into:

program units: Program, Module and Function;
type definitions: Struct, Enum and Union, with StructMethodDeclaration for a type-bound procedure;
data: Variable and Namelist;
names for other symbols: GenericProcedure, CustomOperator and ExternalSymbol;
scopes that are not program units: Block and AssociateBlock;
generics: Requirement and Template.

A symbol declared in one module and used in another is reached through an ExternalSymbol in the using scope, so every symbol an expression names is reachable from the symbol table of the program unit it appears in.