Dwarf format parsing

Debug_line contains the relationship between the address and the source file line

What I want to figure out today is the relationship between the C code of the file and the assembly code:

It has been a blur before, and the problem has been found to have seriously affected the location of the bug.

Before I felt that C and the Assembly could not correspond, but too vague! What is not a single correspondence, in the end is C can correspond to a certain part of the Assembly, or the assembly can correspond to a certain part of C, can you speak clearly?

Hope to see a phenomenon is: can be seen from the dwarf, said this part of the assembly code is the corresponding C language in the first few lines to the first line!~

The addr2line seems to answer my doubts.

Addr2line Enter a virtual address, and Addr2line will report according to this address. What is the virtual address of this address?

[Wonder: What about the functions of inline?]

Specific usage:

An accurate picture of the source program

X29 in arm64 is the stack frame register

Found no stack frame at all!

ARM64 's RET instruction will change the register.

B and ret, the jump instruction will change the register, and the RET instruction will also change the register. But the change is all x30 registers, right? Also includes a status register!

It is possible that the CPU

ARM64 the processing specification is: Caller all the variables to be ready, according to X0 to X7 way ready [], if more than 8 parameters, will put the parameters on the stack, what exactly is the stack frame?

The following code examines the stack frame of the arm64: (The code is simple, but contains a complex set of parameters, including more than 8 formal parameters, when the register is not enough to use the case. And it involves a large return value)

STP X29,X30,[SP, 0x8]! Change the value of the register first, and then do

#include <stdio.h> #include <string.h> #include <stdlib.h>struct big{    char buf[64];    int i;}; int func (int a, int b, int c, int d, int e,          int f, int g, int h, int i, int j) {    return a+b+c+d+e+f+g+h+i+j;} struct Big Funb () {    struct big big_buf;    BIG_BUF.I = func (1,2,3,4,5,6,7,8,9,10);    return big_buf;} int Funa (int a) {    return a+1;} int fun (int a) {    int b, C;    b = a+2;    c = Funa (1);    return a+b+c;} int main () {    int i;    struct big big_buf;    Big_buf = Funb ();    i = BIG_BUF.I;    return fun (i);}   

Dwarf format parsing