可以将运行时检查与修复并继续功能一起使用,以便快速查出并修复编程错误。修复并继续功能提供了强大的组合功能,可以为您节省大量调试时间。以下是一个示例。
% cat -n bug.c 1 #include stdio.h 2 char *s = NULL; 3 4 void 5 problem() 6 { 7 *s = ’c’; 8 } 9 10 main() 11 { 12 problem(); 13 return 0; 14 } % cat -n bug-fixed.c 1 #include stdio.h 2 char *s = NULL; 3 4 void 5 problem() 6 { 7 8 s = (char *)malloc(1); 9 *s = ’c’; 10 } 11 12 main() 13 { 14 problem(); 15 return 0; 16 } yourmachine46: cc -g bug.c yourmachine47: dbx -C a.out Reading symbolic information for a.out Reading symbolic information for rtld /usr/lib/ld.so.1 Reading symbolic information for librtc.so Reading symbolic information for libc.so.1 Reading symbolic information for libintl.so.1 Reading symbolic information for libdl.so.1 Reading symbolic information for libw.so.1 (dbx) check -access access checking - ON (dbx) run Running: a.out (process id 15052) Enabling Error Checking... done Write to unallocated (wua): Attempting to write 1 byte through NULL pointer Current function is problem 7 *s = ’c’; (dbx) pop stopped in main at line 12 in file "bug.c" 12 problem(); (dbx) #at this time we would edit the file; in this example just copy the correct version (dbx) cp bug-fixed.c bug.c (dbx) fix fixing "bug.c" ...... pc moved to "bug.c":14 stopped in main at line 14 in file "bug.c" 14 problem(); (dbx) cont execution completed, exit code is 0 (dbx) quit The following modules in \Qa.out’ have been changed (fixed): bug.c Remember to remake program.
有关使用修复和继续功能的更多信息,请参见内存泄漏 (mel) 错误。