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36 lines
1.4 KiB
Plaintext
36 lines
1.4 KiB
Plaintext
gdb debugging of assembly sources:
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write a function linestab() that generates a .stabd symbol
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independently of the input
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write a function filestab() to generate a .stabs symbol
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we need to take especial care with #line directives
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since we want to handle locore, and locore is passed thru cpp
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this could be tough
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outline of a solution:
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cpp sends us lines of the form
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# logical-line "logical-file" trash
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these lines are interpreted ahead of the gas preprocess pass
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in the starting state, the logical filename is the same
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as the real filename (in case there're no #lines)
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the initial logical line number is 1
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every time we're ready to process a new instruction line,
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if the source file has changed,
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emit a .stabs for the logical file
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emit a .stabd for the logical line
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bump the logical line number
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can gas eat multiple actual lines in one insn?
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i386 nits:
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jmp *$foo produces a short relative branch
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string quotes in comments
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Bill says gas eats text across newlines to find matches
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works fine for me
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I think it's most likely due to cpp
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make / no longer be a comment char
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it's now like the VAX: # is the only comment char
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incorrectly assembles lcall, int3, into, bsr/f instructions
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constant expressions fail if more than a few terms
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gives (low+2)*3+4*5 as an example
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works fine for me
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cpp seems to think $ is a valid literal
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use -$ in /usr/bin/cpp
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