做车展的网站,网页设计与网站建设完全实战手册,网页设计首页尺寸,团购网站怎么做GDB调试
启动程序准备调试
GDB yourpram
或者
先输入GDB
然后输入 file yourpram然后使用run或者r命令开始程序的执行,也可以使用 run parameter将参数传递给该程序参数列表 命令 命令缩写 命令说明 list l 显示多行源代码 break b 设置断点,程序运行到断点的位置会停… GDB调试
启动程序准备调试
GDB yourpram
或者
先输入GDB
然后输入 file yourpram然后使用run或者r命令开始程序的执行,也可以使用 run parameter将参数传递给该程序参数列表 命令 命令缩写 命令说明 list l 显示多行源代码 break b 设置断点,程序运行到断点的位置会停下来 info i 描述程序的状态 run r 开始运行程序 display disp 跟踪查看某个变量,每次停下来都显示它的值 step s 执行下一条语句,如果该语句为函数调用,则进入函数执行其中的第一条语句 next n 执行下一条语句,如果该语句为函数调用,不会进入函数内部执行(即不会一步步地调试函数内部语句) print p 打印内部变量值 continue c 继续程序的运行,直到遇到下一个断点 set var namev 设置变量的值 start st 开始执行程序,在main函数的第一条语句前面停下来 file 装入需要调试的程序 kill k 终止正在调试的程序 watch 监视变量值的变化 backtrace bt 产看函数调用信息(堆栈) frame f 查看栈帧 quit q 退出GDB环境 //e.c#include stdio.h
void debug(char *str)
{printf(debug info :%s\n,str );
}
main(int argc,char *argv[]){int i,j;j0;for(i0;i10;i){j5;printf(now a%d\n, j);}
}gcc -g -o e e.c调试gdb e或者输入gdb然后 file e list 命令用法 list命令显示多行源代码,从上次的位置开始显示,默认情况下,一次显示10行,第一次使用时,从代码其实位置显示 gdb) list#include stdio.hvoid debug(char *str){printf(debug info :%s\n,str );}main(int argc,char *argv[]){int i,j;j0;for(i0;i10;i){j5;
(gdb) list n显示已第n行未中心的10行代码 (gdb) list 8
3 {
4 printf(debug info :%s\n,str );
5 }
6 main(int argc,char *argv[]){
7 int i,j;
8 j0;
9 for(i0;i10;i){
10 j5;
11 printf(now a%d\n, j);
12 }
(gdb) list functionname显示以functionname的函数为中心的10行代码 (gdb) list main
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6 main(int argc,char *argv[]){
7 int i,j;
8 j0;
9 for(i0;i10;i){
10 j5;
(gdb) list - 显示刚才打印过的源代码之前的代码 (gdb) list 10
5 }
6 main(int argc,char *argv[]){
7 int i,j;
8 j0;
9 for(i0;i10;i){
10 j5;
11 printf(now a%d\n, j);
12 }
13 }(gdb) list -
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
(gdb) 断点命令breakbreak location:在location位置设置断点,改位置可以为某一行,某函数名或者其它结构的地址GDB会在执行该位置的代码之前停下来 gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6 main(int argc,char *argv[]){
7 int i,j;
8 j0;
9 for(i0;i10;i){
10 j5;
(gdb)
11 printf(now a%d\n, j);
12 }
13 }(gdb) break 10
Breakpoint 1 at 0x40050a: file e.c, line 10.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e Breakpoint 1, main (argc1, argv0x7fffffffe548) at e.c:10
10 j5;
(gdb) c
Continuing.
now a5Breakpoint 1, main (argc1, argv0x7fffffffe548) at e.c:10
10 j5;
(gdb) c
Continuing.
now a10Breakpoint 1, main (argc1, argv0x7fffffffe548) at e.c:10
10 j5;
(gdb) 使用delete breakpoints 断点号 删除断点这里的断点号表示的是第几个断点,刚才执行break 10返回 reakpoint 1 at 0x40050a: file e.c, line 10.中的1表示该断点的标号因此使用 delete breakpoints 1表示删除第10行所定义的断点clear n表示清除第n行的断点,因此clear 10等同于delete breakpoints 1disable/enable n表示使得编号为n的断点暂时失效或有效可使用info查看断点相关的信息info breakpoints gdb) info breakpoints
No breakpoints or watchpoints.
(gdb) break 10
Breakpoint 2 at 0x40050a: file e.c, line 10.
(gdb) break 9
Breakpoint 3 at 0x400501: file e.c, line 9.
(gdb) info breakpoints
Num Type Disp Enb Address What
2 breakpoint keep y 0x000000000040050a in main at e.c:10
3 breakpoint keep y 0x0000000000400501 in main at e.c:9display命令查看参数的值 (gdb) break 10
Breakpoint 1 at 0x40050a: file e.c, line 10.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e Breakpoint 1, main (argc1, argv0x7fffffffe548) at e.c:10
10 j5;
(gdb) display j
1: j 0
(gdb) c
Continuing.
now a5Breakpoint 1, main (argc1, argv0x7fffffffe548) at e.c:10
10 j5;
1: j 5
(gdb) display
1: j 5
(gdb) display i
2: i 1
(gdb) display j
3: j 5
(gdb) display j*2
4: j*2 10
(gdb) info display
Auto-display expressions now in effect:
Num Enb Expression
4: y j*2
3: y j
2: y i
1: y j也可以使用disable,enable,delete,info命令修改及查看其状态,用法与对断点的一样 step及next命令step可使得程序逐条执行,即执行完一条语句然后在吓一跳语句前停下来,等待用户的命令一般使用step命令是可使用display或者watch命令查看变量的变化,从而判断程序行为是否符合要求当下一条指令为函数时,s进入函数内部,在其第一条语句前停下来step n,next n 表示连续但不执行n条指令,如果期间遇到断点,则停下来 (gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6
7 main(int argc,char *argv[]){
8 int i,j;
9 j0;
10 for(i0;i10;i){
(gdb)
11 j5;
12 printf(now j%d\n, j);
13 debug(xx);
14 }
15 }(gdb)
Line number 16 out of range; e.c has 15 lines.
(gdb) break 11
Breakpoint 1 at 0x40050a: file e.c, line 11.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e1 Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:11
11 j5;
(gdb) s
12 printf(now j%d\n, j);
(gdb) s
__printf (format0x400648 now j%d\n) at printf.c:30
30 {
(gdb) bt
#0 __printf (format0x400648 now j%d\n) at printf.c:30
#1 0x0000000000400525 in main (argc1, argv0x7fffffffe538) at e.c:12
(gdb) n
34 va_start (arg, format);
(gdb) n
35 done vfprintf (stdout, format, arg);
(gdb) n
now j5
39 }
(gdb) bt
#0 __printf (formatvalue optimized out) at printf.c:39
#1 0x0000000000400525 in main (argc1, argv0x7fffffffe538) at e.c:12
(gdb) n
main (argc1, argv0x7fffffffe538) at e.c:13
13 debug(xx);
(gdb) n
debug info :xx
10 for(i0;i10;i){
(gdb) sBreakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:11
11 j5;
(gdb) s
12 printf(now j%d\n, j);
(gdb) n
now j10
13 debug(xx);
(gdb) n
debug info :xx
10 for(i0;i10;i){
(gdb) watchwatch可设置观察点(watchpoint)。使用观察点可以使得当某表达式的值发生变化时,程序暂停执行。执行该命令前必须保证程序已经运行 (gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6
7 main(int argc,char *argv[]){
8 int i,j;
9 j0;
10 for(i0;i10;i){
(gdb)
11 j5;
12 printf(now j%d\n, j);
13 debug(xx);
14 }
15 }(gdb)
Line number 16 out of range; e.c has 15 lines.
(gdb) b main
Breakpoint 1 at 0x4004fa: file e.c, line 9.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e1 Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:9
9 j0;
(gdb) watch j
Hardware watchpoint 2: j
(gdb) c
Continuing.
Hardware watchpoint 2: jOld value 0
New value 5
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j5
debug info :xx
Hardware watchpoint 2: jOld value 5
New value 10
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);print命令 (gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6
7 main(int argc,char *argv[]){
8 int i,j;
9 j0;
10 for(i0;i10;i){
(gdb)
11 j5;
12 printf(now j%d\n, j);
13 debug(xx);
14 }
15 }(gdb)
Line number 16 out of range; e.c has 15 lines.
(gdb) break 12
Breakpoint 1 at 0x40050e: file e.c, line 12.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e1 Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) p j
$1 5
(gdb) c
Continuing.
now j5
debug info :xxBreakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) p i,j
$2 10
(gdb) p j
$3 10
(gdb) set var namevalue在程序运行中动态改变变量的值 (gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6
7 main(int argc,char *argv[]){
8 int i,j;
9 j0;
10 for(i0;i10;i){
(gdb)
11 j5;
12 printf(now j%d\n, j);
13 debug(xx);
14 }
15 }(gdb)
Line number 16 out of range; e.c has 15 lines.
(gdb) break main
Breakpoint 1 at 0x4004fa: file e.c, line 9.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e1 Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:9
9 j0;
(gdb) watch i
Hardware watchpoint 2: i
(gdb) watch j
Hardware watchpoint 3: j
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 0
New value 5
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j5
debug info :xx
Hardware watchpoint 2: iOld value 0
New value 1
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 5
New value 10
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j10
debug info :xx
Hardware watchpoint 2: iOld value 1
New value 2
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 10
New value 15
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j15
debug info :xx
Hardware watchpoint 2: iOld value 2
New value 3
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 15
New value 20
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j20
debug info :xx
Hardware watchpoint 2: iOld value 3
New value 4
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) set var i8
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 20
New value 25
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j25
debug info :xx
Hardware watchpoint 2: iOld value 8
New value 9
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) c
Continuing.
Hardware watchpoint 3: jOld value 25
New value 30
main (argc1, argv0x7fffffffe538) at e.c:12
12 printf(now j%d\n, j);
(gdb) c
Continuing.
now j30
debug info :xx
Hardware watchpoint 2: iOld value 9
New value 10
0x0000000000400533 in main (argc1, argv0x7fffffffe538) at e.c:10
10 for(i0;i10;i){
(gdb) c
Continuing.Watchpoint 2 deleted because the program has left the block in
which its expression is valid.Watchpoint 3 deleted because the program has left the block in
which its expression is valid.
__libc_start_main (main0x4004eb main, argc1, ubp_av0x7fffffffe538, initvalue optimized out, finivalue optimized out, rtld_finivalue optimized out, stack_end0x7fffffffe528) at libc-start.c:258
258 exit (result);
(gdb) c
Continuing.Program exited with code 026.函数调用相关的backtrace可使用frame 查看堆栈中某一帧的信息 (gdb) list
1 #include stdio.h
2 void debug(char *str)
3 {
4 printf(debug info :%s\n,str );
5 }
6
7 main(int argc,char *argv[]){
8 int i,j;
9 j0;
10 for(i0;i10;i){
(gdb)
11 j5;
12 printf(now j%d\n, j);
13 debug(xx);
14 }
15 }(gdb)
Line number 16 out of range; e.c has 15 lines.
(gdb) b 13
Breakpoint 1 at 0x400525: file e.c, line 13.
(gdb) r
Starting program: /mnt/hgfs/www/c/gcc/e1
now j5Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:13
13 debug(xx);
(gdb) s
debug (str0x400652 xx) at e.c:4
4 printf(debug info :%s\n,str );
(gdb) bt
#0 debug (str0x400652 xx) at e.c:4
#1 0x000000000040052f in main (argc1, argv0x7fffffffe538) at e.c:13
(gdb) s
__printf (format0x400638 debug info :%s\n) at printf.c:30
30 {
(gdb) bt
#0 __printf (format0x400638 debug info :%s\n) at printf.c:30
#1 0x00000000004004e9 in debug (str0x400652 xx) at e.c:4
#2 0x000000000040052f in main (argc1, argv0x7fffffffe538) at e.c:13
(gdb) s
34 va_start (arg, format);
(gdb) bt
#0 __printf (format0x400638 debug info :%s\n) at printf.c:34
#1 0x00000000004004e9 in debug (str0x400652 xx) at e.c:4
#2 0x000000000040052f in main (argc1, argv0x7fffffffe538) at e.c:13
(gdb) s
35 done vfprintf (stdout, format, arg);
(gdb) s
_IO_vfprintf_internal (s0x333a58f040, format0x400638 debug info :%s\n, ap0x7fffffffe330) at vfprintf.c:236
236 int save_errno errno;
(gdb) bt
#0 _IO_vfprintf_internal (s0x333a58f040, format0x400638 debug info :%s\n, ap0x7fffffffe330) at vfprintf.c:236
#1 0x000000333a24effa in __printf (formatvalue optimized out) at printf.c:35
#2 0x00000000004004e9 in debug (str0x400652 xx) at e.c:4
#3 0x000000000040052f in main (argc1, argv0x7fffffffe538) at e.c:13
(gdb) c
Continuing.
debug info :xx
now j10Breakpoint 1, main (argc1, argv0x7fffffffe538) at e.c:13
13 debug(xx);
(gdb) bt
#0 main (argc1, argv0x7fffffffe538) at e.c:13 转载于:https://www.cnblogs.com/yuanqiangfei/p/10410533.html
