[RFC] multiple code segments and the interpreter

[Leopold Toetsch]

The variable layout of interpreter->code (actually the packfile) doesn't fit very good for multiple code segments. There is only one ->byte_code pointer, the byte_code_size is in bytes and converted zig times into opcode_t's and so on.

so:

1) rename interpreter->code to interpreter->pf (the packfile)

The packfile owns all PBC segments: byte_code, const_table and so on. These segments are all organized in the directory segment. Eval'ing code generates a new code segment and appends constants to the const_table, so far so good: But how to load a precompiled PBC module whith its own const_table (with constants numbered from 0 and spread all over the code). So:

2) we need multiple constant_tables too.

As one or more code segments may refer to these constants, they constant_table must be linked to these code segments.

3) one PBC file has exactly one const_table (or none if no constants are used) and may have multiple code segments

For switching code segments (with the intersegment jump instruction), we setup this new pointer:

4) interpreter->code ... points to current executing byte_code seg
interpreter->code->const_table ... to current code segs constant

Comments welcome,
leo