我有一段代码,检查是否已经定义一个宏,如果它不是,那么它分配一个新的宏的内存并添加它到当前列表中。如果它已经定义,那么它只是改变宏体,并保持名称相同。得到一个Seg错误11错误,并不知道为什么
static struct macro *macro_lookup(char *name){
struct macro * temp = ¯o_list;
while(temp->next != NULL){
if(strcmp(temp->macro_name,name) == 0){
return temp;
}
}
return NULL;
}
void macro_set(char *name, char *body){
//Need to check to see if a macro is already set for the name if so just change the body
struct macro * p = macro_lookup(name); //Will return NULL if macro is not in the list. This line gives me the error of segmentation fault 11, if I comment it out the program works.
//Need to make a new macro and add it to the list
if(p == NULL){
//Make a new macro
struct macro * new_macro = (struct macro *) Malloc(sizeof(struct macro)); //Malloc is my version of malloc, it works just fine.
if(new_macro == NULL){
fprintf(stderr,"Error while allocating space for the new marco.\n");
exit(EXIT_FAILURE);
}
new_macro->macro_name = name;
new_macro->macro_body = body;
//Create a pointer to the list and traverse it until the end and put the new macro there
struct macro * temp = ¯o_list;
while(temp->next != NULL){
temp = temp->next;
}
temp->next = new_macro;
}
//The macro already exists and p is pointing to it
else{
//Just change the body of the macro
p->macro_body = body;
}
}
我不知道为什么上面的错误行给了我一个问题,我可以静态集合P为空,测试它,它工作正常,但是当我使用macro_lookup功能它得到一个赛格故障。
您应该学习如何使用调试器。它将帮助您找出程序崩溃的确切线条,并让您检查变量以查看它们中的任何一个是否是例如'NULL'。 Linux中最常见的调试器可能是[GDB](http://www.gnu.org/software/gdb/)。 – 2012-03-13 06:22:52