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Diffstat (limited to 'gnu/gas/NOTES')
| -rw-r--r-- | gnu/gas/NOTES | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/gnu/gas/NOTES b/gnu/gas/NOTES new file mode 100644 index 000000000000..b3f3f92d2ef7 --- /dev/null +++ b/gnu/gas/NOTES @@ -0,0 +1,35 @@ +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 |