usr/src/contrib/gas-1.38/NOTES

gdb debugging of assembly sources:
        write a function linestab() that generates a .stabd symbol
                independently of the input
        write a function filestab() to generate a .stabs symbol
        we need to take especial care with #line directives
                since we want to handle locore, and locore is passed thru cpp
                this could be tough
        outline of a solution:
                cpp sends us lines of the form
                        # logical-line "logical-file" trash
                these lines are interpreted ahead of the gas preprocess pass
                in the starting state, the logical filename is the same
                        as the real filename (in case there're no #lines)
                the initial logical line number is 1
                every time we're ready to process a new instruction line,
                        if the source file has changed,
                                emit a .stabs for the logical file
                        emit a .stabd for the logical line
                        bump the logical line number
                                can gas eat multiple actual lines in one insn?

i386 nits:
        jmp *$foo produces a short relative branch
        string quotes in comments
                Bill says gas eats text across newlines to find matches
                works fine for me
                I think it's most likely due to cpp
        make / no longer be a comment char
                it's now like the VAX: # is the only comment char
        incorrectly assembles lcall, int3, into, bsr/f instructions
        constant expressions fail if more than a few terms
                gives (low+2)*3+4*5 as an example
                works fine for me
        cpp seems to think $ is a valid literal
                use -$ in /usr/bin/cpp