This frees FL_USER0 on both T_MODULE and T_CLASS.
Note: prior to this, FL_SINGLETON was never set on T_MODULE,
so checking for `FL_SINGLETON` without first checking that
`FL_TYPE` was `T_CLASS` was valid. That's no longer the case.
String nodes holds ruby string object on `VALUE nd_lit`.
This commit changes it to `struct rb_parser_string *string`
to reduce dependency on ruby object.
Sometimes these strings are concatenated with other string
therefore string concatenate functions are needed.
`__ENCODING__ `was managed by `NODE_LIT` with Encoding object.
Introduce `NODE_ENCODING` for
1. `__ENCODING__` is detectable from AST Node.
2. Reduce dependency Ruby object for parse.y
`:sym` was managed by `NODE_LIT` with `Symbol` object.
This commit introduces `NODE_SYM` so that
1. Symbol literal is detectable from AST Node
2. Reduce dependency on ruby object
`__FILE__` was managed by `NODE_STR` with `String` object.
This commit introduces `NODE_FILE` and `struct rb_parser_string` so that
1. `__FILE__` is detectable from AST Node
2. Reduce dependency ruby object
`__LINE__` was managed by `NODE_LIT` with `Integer` object.
This commit introduces `NODE_LINE` so that
1. `__LINE__` is detectable from AST Node
2. Reduce dependency ruby object
ARGSCAT has been used for nd_args to hold index and rvalue,
because there was limitation on the number of members for Node.
We can easily change structure of node now, let's expand it.
All kind of AST nodes use same struct RNode, which has u1, u2, u3 union members
for holding different kind of data.
This has two problems.
1. Low flexibility of data structure
Some nodes, for example NODE_TRUE, don’t use u1, u2, u3. On the other hand,
NODE_OP_ASGN2 needs more than three union members. However they use same
structure definition, need to allocate three union members for NODE_TRUE and
need to separate NODE_OP_ASGN2 into another node.
This change removes the restriction so make it possible to
change data structure by each node type.
2. No compile time check for union member access
It’s developer’s responsibility for using correct member for each node type when it’s union.
This change clarifies which node has which type of fields and enables compile time check.
This commit also changes node_buffer_elem_struct buf management to handle
different size data with alignment.
After a0f12a0258 NODE_GASGN and
NODE_GVAR hold same value on both nd_vid and nd_entry.
This commit stops setting value to nd_entry and makes to use only
nd_vid.