// Parse a declaration.
//
// declaration:
// [specifier-seq] basic-declaration
//
// basic-declaration:
// variable-declaration
// function-declaration
// type-declaration
// concept-declaration
Decl&
Parser::declaration()
{
// Parse and cache the specifier sequences.
specifier_seq();
switch (lookahead()) {
case tk::var_tok:
return variable_declaration();
case tk::def_tok:
return function_declaration();
case tk::class_tok:
return class_declaration();
case tk::concept_tok:
lingo_unreachable();
case tk::super_tok:
return super_declaration();
default:
break;
}
throw Syntax_error("invalid declaration");
}
virtual void postorder(Context ctx, AST_t node)
{
DeclaredEntity function_declaration(node, ctx.scope_link);
AugmentedSymbol symbol = function_declaration.get_declared_symbol();
if (symbol.is_task())
{
_table.insert(symbol);
}
}
void global_declaration() {
// global_declaration ::= enum_decl | variable_decl | function_decl
//
// enum_decl ::= 'enum' [id] '{' id ['=' 'num'] {',' id ['=' 'num'} '}'
//
// variable_decl ::= type {'*'} id { ',' {'*'} id } ';'
//
// function_decl ::= type {'*'} id '(' parameter_decl ')' '{' body_decl '}'
int type; // tmp, actual type for variable
int i; // tmp
basetype = INT;
// parse enum, this should be treated alone.
if (token == Enum) {
// enum [id] { a = 10, b = 20, ... }
match(Enum);
if (token != '{') {
match(Id); // skip the [id] part
}
if (token == '{') {
// parse the assign part
match('{');
enum_declaration();
match('}');
}
match(';');
return;
}
// parse type information
if (token == Int) {
match(Int);
}
else if (token == Char) {
match(Char);
basetype = CHAR;
}
// parse the comma seperated variable declaration.
while (token != ';' && token != '}') {
type = basetype;
// parse pointer type, note that there may exist `int ****x;`
while (token == Mul) {
match(Mul);
type = type + PTR;
}
if (token != Id) {
// invalid declaration
printf("%d: bad global declaration\n", line);
exit(-1);
}
if (current_id[Class]) {
// identifier exists
printf("%d: duplicate global declaration\n", line);
exit(-1);
}
match(Id);
current_id[Type] = type;
if (token == '(') {
current_id[Class] = Fun;
current_id[Value] = (int)(text + 1); // the memory address of function
function_declaration();
} else {
// variable declaration
current_id[Class] = Glo; // global variable
current_id[Value] = (int)data; // assign memory address
data = data + sizeof(int);
}
if (token == ',') {
match(',');
}
}
next();
}
virtual void postorder(Context ctx, AST_t node)
{
DeclaredEntity function_declaration(node, ctx.scope_link);
AugmentedSymbol symbol = function_declaration.get_declared_symbol();
_table.insert( FunctionTable::table_t::value_type(symbol.get_qualified_name(), symbol) );
}
void global_declaration() {
int type;
int i;
basetype = Int;
if (token == Enum) {
match(Enum);
if (token == Id) {
match(Id);
}
if (token == '{') {
match('{');
enum_declaration();
match('}');
}
match(';');
return;
}
if (token == Int) {
match(Int);
} else if (token == Char) {
match(Char);
basetype = Char;
}
while (token != ';' && token != '}') {
type = basetype;
while (token == Mul) {
match(Mul);
type = type + PTR;
}
if (token != Id) {
printf("%d: bad global declaration\n", line);
exit(-1);
}
if (current_id[Class]) {
printf("%d: duplicate global declaration\n", line);
exit(-1);
}
match(Id);
current_id[Type] = type;
if (token == '(') {
current_id[Class] = Fun;
current_id[Value] = (int)(text + 1);
function_declaration();
} else {
current_id[Class] = Glo;
current_id[Value] = (int)data;
data = data + sizeof(int);
}
if (token == ','){
match(',');
}
}
next();
}
