I found this description in GCC Internals info file.
------------------------------------------------------------------------
11.7 Constant Expression Types
==============================
...
`(const:M EXP)'
Represents a constant that is the result of an assembly-time
arithmetic computation. The operand, EXP, is an expression that
contains only constants (`const_int', `symbol_ref' and `label_ref'
expressions) combined with `plus' and `minus'. However, not all
combinations are valid, since the assembler cannot do arbitrary
arithmetic on relocatable symbols.
M should be `Pmode'.
------------------------------------------------------------------------
Are there any plan to implement this facility as an extension to
object file format?
I don't know the fact but I suppose why linker was originally
invented was to promise user to recompile only modified .c files,
and this principal was broken with object oriented programming.
I think with this facility, simple OO language will be much cleaner
than the current, because the offset of member variables or method
table are resolved in link phase.
Please comment.
---
Mikiya Matsuzaka
