代码:
1 #include
2
3 int func(int n)
4 {
5 int sum=0,i;
6 for(i=0; i
7 {
8 sum+=i;
9 }
10 return sum;
11 }
12
13
14 main()
15 {
16 int i;
17 long result = 0;
18 for(i=1; i <=100; i++)
19 {
20 result += i;
21 }
22
23 printf("result[1-100] = %d
", result );
24 printf("result[1-250] = %d
", func(250) );
25 }
编译生成执行文件:(Linux下)
hchen/test> cc -g tst.c -o tst
使用GDB调试:
代码:
hchen/test> gdb tst <---------- 启动GDB
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-suse-linux"...
(gdb) l <-------------------- l命令相当于list,从第一行开始例出原码。
1 #include
2
3 int func(int n)
4 {
5 int sum=0,i;
6 for(i=0; i
7 {
8 sum+=i;
9 }
10 return sum;
(gdb) <-------------------- 直接回车表示,重复上一次命令
11 }
12
13
14 main()
15 {
16 int i;
17 long result = 0;
18 for(i=1; i <=100; i++)
19 {
20 result += i;
(gdb) break 16 <-------------------- 设置断点,在源程序第16行处。
Breakpoint 1 at 0x8048496: file tst.c, line 16.
(gdb) break func <-------------------- 设置断点,在函数func()入口处。
Breakpoint 2 at 0x8048456: file tst.c, line 5.
(gdb) info break <-------------------- 查看断点信息。
Num Type Disp Enb Address What
1 breakpoint keep y 0x08048496 in main at tst.c:16
2 breakpoint keep y 0x08048456 in func at tst.c:5
(gdb) r <--------------------- 运行程序,run命令简写
Starting program: /home/hchen/test/tst
Breakpoint 1, main () at tst.c:17 <---------- 在断点处停住。
17 long result = 0;
(gdb) n <--------------------- 单条语句执行,next命令简写。
18 for(i=1; i <=100; i++)
(gdb) n
20 result += i;
(gdb) n
18 for(i=1; i <=100; i++)
(gdb) n
20 result += i;
(gdb) c <--------------------- 继续运行程序,continue命令简写。
Continuing.
result[1-100] = 5050 <----------程序输出。
Breakpoint 2, func (n=250) at tst.c:5
5 int sum=0,i;
(gdb) n
6 for(i=1; i <=n; i++)
(gdb) p i <--------------------- 打印变量i的值,print命令简写。
$1 = 134513808
(gdb) n
8 sum+=i;
(gdb) n
6 for(i=1; i <=n; i++)
(gdb) p sum
$2 = 1
(gdb) n
8 sum+=i;
(gdb) p i
$3 = 2
(gdb) n
6 for(i=1; i <=n; i++)
(gdb) p sum
$4 = 3
(gdb) bt <--------------------- 查看函数堆栈。
#0 func (n=250) at tst.c:5
#1 0x080484e4 in main () at tst.c:24
#2 0x400409ed in __libc_start_main () from /lib/libc.so.6
(gdb) finish <--------------------- 退出函数。
Run till exit from #0 func (n=250) at tst.c:5
0x080484e4 in main () at tst.c:24
24 printf("result[1-250] = %d
", func(250) );
Value returned is $6 = 31375
(gdb) c <--------------------- 继续运行。
Continuing.
result[1-250] = 31375 <----------程序输出。
Program exited with code 027. <--------程序退出,调试结束。
(gdb) q <--------------------- 退出gdb。
hchen/test>
-directory
-d
加入一个源文件的搜索路径。默认搜索路径是环境变量中PATH所定义的路径。
GDB的命令概貌
启动gdb后,就你被带入gdb的调试环境中,就可以使用gdb的命令开始调试程序了,gdb的命令可以使用help命令来查看,如下所示:
/home/hchen> gdb
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-suse-linux".
(gdb) help
List of classes of commands:
aliases -- Aliases of other commands
breakpoints -- Making program stop at certain points
data -- Examining data
files -- Specifying and examining files
internals -- Maintenance commands
obscure -- Obscure features
running -- Running the program
stack -- Examining the stack
status -- Status inquiries
support -- Support facilities
tracepoints -- Tracing of program execution without stopping the program
user-defined -- User-defined commands
Type "help" followed by a class name for a list of commands in that class.
Type "help" followed by command name for full documentation.
Command name abbreviations are allowed if unambiguous.
(gdb)
gdb的命令很多,gdb把之分成许多个种类。help命令只是例出gdb的命令种类,如果要看种类中的命令,可以使用help 命令,如:help breakpoints,查看设置断点的所有命令。也可以直接help 来查看命令的帮助。
gdb中,输入命令时,可以不用打全命令,只用打命令的前几个字符就可以了,当然,命令的前几个字符应该要标志着一个唯一的命令,在Linux下,你可以敲击两次TAB键来补齐命令的全称,如果有重复的,那么gdb会把其例出来。
示例一:在进入函数func时,设置一个断点。可以敲入break func,或是直接就是b func
(gdb) b func
Breakpoint 1 at 0x8048458: file hello.c, line 10.
示例二:敲入b按两次TAB键,你会看到所有b打头的命令:
(gdb) b
backtrace break bt
(gdb)
示例三:只记得函数的前缀,可以这样:
(gdb) b make_ <按TAB键>
(再按下一次TAB键,你会看到:)
make_a_section_from_file make_environ
make_abs_section make_function_type
make_blockvector make_pointer_type
make_cleanup make_reference_type
make_command make_symbol_completion_list
(gdb) b make_
GDB把所有make开头的函数全部例出来给你查看。
示例四:调试C++的程序时,有可以函数名一样。如:
(gdb) b 'bubble( M-?
bubble(double,double) bubble(int,int)
(gdb) b 'bubble(
你可以查看到C++中的所有的重载函数及参数。(注:M-?和“按两次TAB键”是一个意思)
$ gdb --core=core.9128
GNU gdb Asianux (6.0post-0.20040223.17.1AX)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-asianux-linux-gnu".
Core was generated by `./a.out'.
Program terminated with signal 11, Segmentation fault.
#0 0x08048373 in ?? ()
(gdb) bt
#0 0x08048373 in ?? ()
#1 0xbfffd8f8 in ?? ()
#2 0x0804839e in ?? ()
#3 0xb74cc6b3 in ?? ()
#4 0x00000000 in ?? ()
(gdb) file ./a.out
Reading symbols from ./a.out...done.
Using host libthread_db library "/lib/tls/libthread_db.so.1".
(gdb) bt
#0 0x08048373 in sub () at foo.c:17
#1 0x08048359 in main () at foo.c:8
代码:
1 #include
2
3 int func(int n)
4 {
5 int sum=0,i;
6 for(i=0; i
7 {
8 sum+=i;
9 }
10 return sum;
11 }
12
13
14 main()
15 {
16 int i;
17 long result = 0;
18 for(i=1; i<=100; i++)
19 {
20 result += i;
21 }
22
23 printf("result[1-100] = %d
", result );
24 printf("result[1-250] = %d
", func(250) );
25 }
编译生成执行文件:(Linux下)
hchen/test> cc -g tst.c -o tst
使用GDB调试:
代码:
hchen/test> gdb tst <---------- 启动GDB
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-suse-linux"...
(gdb) l <-------------------- l命令相当于list,从第一行开始例出原码。
1 #include
2
3 int func(int n)
4 {
5 int sum=0,i;
6 for(i=0; i
7 {
8 sum+=i;
9 }
10 return sum;
(gdb) <-------------------- 直接回车表示,重复上一次命令
11 }
12
13
14 main()
15 {
16 int i;
17 long result = 0;
18 for(i=1; i<=100; i++)
19 {
20 result += i;
(gdb) break 16 <-------------------- 设置断点,在源程序第16行处。
Breakpoint 1 at 0x8048496: file tst.c, line 16.
(gdb) break func <-------------------- 设置断点,在函数func()入口处。
Breakpoint 2 at 0x8048456: file tst.c, line 5.
(gdb) info break <-------------------- 查看断点信息。
Num Type Disp Enb Address What
1 breakpoint keep y 0x08048496 in main at tst.c:16
2 breakpoint keep y 0x08048456 in func at tst.c:5
(gdb) r <--------------------- 运行程序,run命令简写
Starting program: /home/hchen/test/tst
Breakpoint 1, main () at tst.c:17 <---------- 在断点处停住。
17 long result = 0;
(gdb) n <--------------------- 单条语句执行,next命令简写。
18 for(i=1; i<=100; i++)
(gdb) n
20 result += i;
(gdb) n
18 for(i=1; i<=100; i++)
(gdb) n
20 result += i;
(gdb) c <--------------------- 继续运行程序,continue命令简写。
Continuing.
result[1-100] = 5050 <----------程序输出。
Breakpoint 2, func (n=250) at tst.c:5
5 int sum=0,i;
(gdb) n
6 for(i=1; i<=n; i++)
(gdb) p i <--------------------- 打印变量i的值,print命令简写。
$1 = 134513808
(gdb) n
8 sum+=i;
(gdb) n
6 for(i=1; i<=n; i++)
(gdb) p sum
$2 = 1
(gdb) n
8 sum+=i;
(gdb) p i
$3 = 2
(gdb) n
6 for(i=1; i<=n; i++)
(gdb) p sum
$4 = 3
(gdb) bt <--------------------- 查看函数堆栈。
#0 func (n=250) at tst.c:5
#1 0x080484e4 in main () at tst.c:24
#2 0x400409ed in __libc_start_main () from /lib/libc.so.6
(gdb) finish <--------------------- 退出函数。
Run till exit from #0 func (n=250) at tst.c:5
0x080484e4 in main () at tst.c:24
24 printf("result[1-250] = %d
", func(250) );
Value returned is $6 = 31375
(gdb) c <--------------------- 继续运行。
Continuing.
result[1-250] = 31375 <----------程序输出。
Program exited with code 027. <--------程序退出,调试结束。
(gdb) q <--------------------- 退出gdb。
hchen/test>
-directory
-d
加入一个源文件的搜索路径。默认搜索路径是环境变量中PATH所定义的路径。
GDB的命令概貌
启动gdb后,就你被带入gdb的调试环境中,就可以使用gdb的命令开始调试程序了,gdb的命令可以使用help命令来查看,如下所示:
/home/hchen> gdb
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-suse-linux".
(gdb) help
List of classes of commands:
aliases -- Aliases of other commands
breakpoints -- Making program stop at certain points
data -- Examining data
files -- Specifying and examining files
internals -- Maintenance commands
obscure -- Obscure features
running -- Running the program
stack -- Examining the stack
status -- Status inquiries
support -- Support facilities
tracepoints -- Tracing of program execution without stopping the program
user-defined -- User-defined commands
Type "help" followed by a class name for a list of commands in that class.
Type "help" followed by command name for full documentation.
Command name abbreviations are allowed if unambiguous.
(gdb)
gdb的命令很多,gdb把之分成许多个种类。help命令只是例出gdb的命令种类,如果要看种类中的命令,可以使用help 命令,如:help breakpoints,查看设置断点的所有命令。也可以直接help 来查看命令的帮助。
gdb中,输入命令时,可以不用打全命令,只用打命令的前几个字符就可以了,当然,命令的前几个字符应该要标志着一个唯一的命令,在Linux下,你可以敲击两次TAB键来补齐命令的全称,如果有重复的,那么gdb会把其例出来。
示例一:在进入函数func时,设置一个断点。可以敲入break func,或是直接就是b func
(gdb) b func
Breakpoint 1 at 0x8048458: file hello.c, line 10.
示例二:敲入b按两次TAB键,你会看到所有b打头的命令:
(gdb) b
backtrace break bt
(gdb)
示例三:只记得函数的前缀,可以这样:
(gdb) b make_ <按TAB键>
(再按下一次TAB键,你会看到:)
make_a_section_from_file make_environ
make_abs_section make_function_type
make_blockvector make_pointer_type
make_cleanup make_reference_type
make_command make_symbol_completion_list
(gdb) b make_
GDB把所有make开头的函数全部例出来给你查看。
示例四:调试C++的程序时,有可以函数名一样。如:
(gdb) b 'bubble( M-?
bubble(double,double) bubble(int,int)
(gdb) b 'bubble(
你可以查看到C++中的所有的重载函数及参数。(注:M-?和“按两次TAB键”是一个意思)