Making macro expanded when Debug GNU assembly program using GDB

Question

I write a program using assembly language and compile it by GCC as following:

gcc -g sha256-avx.S main256.c -o test.exe

Now, I need to debug it. But I don't know how to the content of macro. The following is my method about using GDB.

(gdb) s
400     vmovdqa XFER, _XFER(%rsp)
(gdb) s
401     FOUR_ROUNDS_AND_SCHED
(gdb) s
403     vpaddd  1*16(TBL), X0, XFER
(gdb) s
404     vmovdqa XFER, _XFER(%rsp)
(gdb) s
405     FOUR_ROUNDS_AND_SCHED

FOUR_ROUNDS_AND_SCHED is a macro defined by myself.

.macro FOUR_ROUNDS_AND_SCHED
 ## compute s0 four at a time and s1 two at a time
 ## compute W[-16] + W[-7] 4 at a time

 mov     e, y0          # y0 = e
 MY_ROR  (25-11), y0             # y0 = e >> (25-11)
 mov     a, y1                   # y1 = a
 vpalignr $4, X2, X3, XTMP0      # XTMP0 = W[-7]
 MY_ROR  (22-13), y1             # y1 = a >> (22-13)
 xor     e, y0                   # y0 = e ^ (e >> (25-11))
 mov     f, y2                   # y2 = f
 MY_ROR  (11-6), y0              # y0 = (e >> (11-6)) ^ (e >> (25-6))
 xor     a, y1                   # y1 = a ^ (a >> (22-13)

 // ...
.endm

In fact, My_ROR is also a macro defined in my program.

I want to watch the every instruction in macro(FOUR_ROUNDS_AND_SCHED and My_ROR) when debug program step-by-step using GDB. How should I compile my program?

Employed Russian · Accepted Answer · 2019-09-12 00:34:34Z

3

How should I compile my program?

You can compile the program as you do now, but use x/4i $pc to see actual instructions, and stepi to single step instructions instead of lines.

answered Sep 12, 2019 at 0:34

Employed Russian

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3 Comments

Land Over a year ago

x/4i $pc instruction make me see some instructions that will be executed. But it isn't that I hope.

Land Over a year ago

I hope step-by-step to see each instructions that are executed currently.

Land Over a year ago

Hope you give me a better solution.

Christian B · Accepted Answer · 2019-09-15 05:52:12Z

1

Try combining disp/i $pc with stepi?

answered Sep 15, 2019 at 5:52

Christian B

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