GDB debugging (5) Checking file search and view Assembly commands

 

1. source code file search

You can use the following three commands to find the source file for GDB debugging.

 

Forward-searchRegexp

Search for the keyword Regexp from the first line of the source file and record the row number. This record can be referenced by the next GDB command.

 

Example: for void

Search Result: 38 void

Next, run the command: List to display 10 lines of content centered on 38 behaviors. (The number of rows to be displayed can be specified)

 

Search Regexp

Search down from the current row.

 

Reverse-search Regexp

Search from the last line.

 

2. View machine commands (assembly)

 

Disassemble

Disassemble/M hexadecimal display Assembly command

Disassemble/R

Disassemble start, end specifies the start and end addresses

Disassemble start, + length specifies the start address and display Length

 

You can obtain the address using the following column:

(GDB) info line main

Line 895 of "builtin. c" starts at PC 0x634c and ends at 0x6350.

 

(GDB) info line * 0x63ff

Line 926 of "builtin. c" starts at PC 0x63e4 and ends at 0x6404.

 

     (gdb) disas 0x634c, 0x6404

     Dump of assembler code from 0x32c4 to 0x32e4:

        0x32c4 <main+204>:      addil 0,dp

        0x32c8 <main+208>:      ldw 0x22c(sr0,r1),r26

        0x32cc <main+212>:      ldil 0x3000,r31

        0x32d0 <main+216>:      ble 0x3f8(sr4,r31)

        0x32d4 <main+220>:      ldo 0(r31),rp

        0x32d8 <main+224>:      addil -0x800,dp

        0x32dc <main+228>:      ldo 0x588(r1),r26

        0x32e0 <main+232>:      ldil 0x3000,r31

     End of assembler dump.