# 打印函數堆棧幀信息 ## 例子 #include <stdio.h> int func(int a, int b) { int c = a * b; printf("c is %d\n", c); } int main(void) { func(1, 2); return 0; } ## 技巧 使用gdb調試程序時，可以使用“`i frame`”命令（`i`是`info`命令縮寫）顯示函數堆棧幀信息。以上面程序為例： Breakpoint 1, func (a=1, b=2) at a.c:5 5 printf("c is %d\n", c); (gdb) i frame Stack level 0, frame at 0x7fffffffe590: rip = 0x40054e in func (a.c:5); saved rip = 0x400577 called by frame at 0x7fffffffe5a0 source language c. Arglist at 0x7fffffffe580, args: a=1, b=2 Locals at 0x7fffffffe580, Previous frame's sp is 0x7fffffffe590 Saved registers: rbp at 0x7fffffffe580, rip at 0x7fffffffe588 (gdb) i registers rax 0x2 2 rbx 0x0 0 rcx 0x0 0 rdx 0x7fffffffe688 140737488348808 rsi 0x2 2 rdi 0x1 1 rbp 0x7fffffffe580 0x7fffffffe580 rsp 0x7fffffffe560 0x7fffffffe560 r8 0x7ffff7dd4e80 140737351863936 r9 0x7ffff7dea560 140737351951712 r10 0x7fffffffe420 140737488348192 r11 0x7ffff7a35dd0 140737348066768 r12 0x400440 4195392 r13 0x7fffffffe670 140737488348784 r14 0x0 0 r15 0x0 0 rip 0x40054e 0x40054e <func+24> eflags 0x202 [ IF ] cs 0x33 51 ss 0x2b 43 ds 0x0 0 es 0x0 0 fs 0x0 0 gs 0x0 0 (gdb) disassemble func Dump of assembler code for function func: 0x0000000000400536 <+0>: push %rbp 0x0000000000400537 <+1>: mov %rsp,%rbp 0x000000000040053a <+4>: sub $0x20,%rsp 0x000000000040053e <+8>: mov %edi,-0x14(%rbp) 0x0000000000400541 <+11>: mov %esi,-0x18(%rbp) 0x0000000000400544 <+14>: mov -0x14(%rbp),%eax 0x0000000000400547 <+17>: imul -0x18(%rbp),%eax 0x000000000040054b <+21>: mov %eax,-0x4(%rbp) => 0x000000000040054e <+24>: mov -0x4(%rbp),%eax 0x0000000000400551 <+27>: mov %eax,%esi 0x0000000000400553 <+29>: mov $0x400604,%edi 0x0000000000400558 <+34>: mov $0x0,%eax 0x000000000040055d <+39>: callq 0x400410 <printf@plt> 0x0000000000400562 <+44>: leaveq 0x0000000000400563 <+45>: retq End of assembler dump. 可以看到執行“`i frame`”命令后，輸出了當前函數堆棧幀的地址，指令寄存器的值，局部變量地址及值等信息，可以對照當前寄存器的值和函數的匯編指令看一下。 參見[gdb手冊](https://sourceware.org/gdb/onlinedocs/gdb/Frame-Info.html). ## 貢獻者 nanxiao