c - gdb 'info types' 不打印 C 结构

Question

我想使用 gdb 的信息类型来了解结构的外观。

看到以下行为:
如果结构体定义为:

typedef struct {
...
...
} XX;

info types 命令显示结构格式。

但是如果它没有经过 typedef 编辑，info types 只是告诉它是一个结构。没有提供其成员的详细信息。

这是预期的行为吗？我是否忽略了什么？无论如何要通过信息类型使结构可见？ (无需更改代码)。

Answer 1

您可以使用ptype，请参阅内置帮助:

(gdb) help ptype 
Print definition of type TYPE.
Usage: ptype[/FLAGS] TYPE | EXPRESSION
Argument may be any type (for example a type name defined by typedef,
or "struct STRUCT-TAG" or "class CLASS-NAME" or "union UNION-TAG"
or "enum ENUM-TAG") or an expression.
The selected stack frame's lexical context is used to look up the name.
Contrary to "whatis", "ptype" always unrolls any typedefs.

Available FLAGS are:
  /r    print in "raw" form; do not substitute typedefs
  /m    do not print methods defined in a class
  /M    print methods defined in a class
  /t    do not print typedefs defined in a class
  /T    print typedefs defined in a class
(gdb) 

以下是 redisContext 的示例:

(gdb) ptype redisContext
type = struct redisContext {
    int err;
    char errstr[128];
    int fd;
    int flags;
    char *obuf;
    redisReader *reader;
    enum redisConnectionType connection_type;
    struct timeval *timeout;
    struct {
        char *host;
        char *source_addr;
        int port;
    } tcp;
    struct {
        char *path;
    } unix_sock;
}
(gdb)