(第六章调试.pptVIP

3-1避免使用表达式宏 #define RS_is_null (RS_node-var_value == Nnull_string) ... if (RS_is_null || today == TUESDAY) (gdb) print RS_is_null No symbol RS_is_null in current context. 宏在编译的预处理中已经被替换。所以在可执行文件中没有符号列表 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3-1避免使用表达式宏 #define NOSTATE 1 /* scanning not started yet (all) */ #define INLEADER 2 /* skipping leading data (RS = ) */ #define INDATA 3 /* in body of record (all) */ #define INTERM 4 /* scanning terminator (RS = , RS = regexp) */ int state; ... state = NOSTATE; ... state = INLEADER; ... if (state != INTERM) ... (gdb) print state $1 = 2 2代表什么？你只有在回溯代码才知道，造成不便，是否可以直接打印出来她的含义？ Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3-1避免使用表达式宏 typedef enum scanstate { NOSTATE, /* scanning not started yet (all) */ INLEADER, /* skipping leading data (RS = ) */ INDATA, /* in body of record (all) */ INTERM, /* scanning terminator (RS = , RS = regexp) */ } SCANSTATE; SCANSTATE state; ...rest of code remains unchanged!... (gdb) print state $1 = NOSTATE 使用enum便变量代替红地对能够以就可以解决此问题。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3-2添加调试选项和变量 加入一个启动调试的命令选项 如果规模较大，可以针对单独模块 为不同的模块设置位标记 $myprog --debug Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3-2添加调试选项和变量 struct option options[] = { ... { debug, required_argument, NULL, D }, ... }; 设定短选项-D或长选项--debug int main(int argc, char **argv) { int c; while ((c = getopt_long(argc, argv, ...D:)) != -1) { switch (c) { ... case D: parse_debug(optarg); break; ... } } ... } 如果指定了debug选项，需要分析debug选项的参数。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client