C 可能的错误？带点表示法的结构中缺少初始值设定项

我正在使用这些

gcc

标志编译我的程序：

-std=c11-Wall-Wextra-pedantic

我尝试使用带有字段标签的初始值设定项初始化结构，而不是记住每个字段的正确顺序。然而，我得到了一些我不理解的警告。在另一个问题中，有人声称这可能是一个

gcc

bug。。。我不知道

这是我的密码。我尝试使用冒号

：

表示法，但我收到一个过时的初始值设定项警告，所以我切换到了点

表示法

这真的只是一个bug，还是我做错了什么？我可以压制这个警告，但我认为它本来就不应该在那里。我仔细检查了我的代码，它应该是正确的，对吗？编译器应该很高兴，不要发出警告

如果我错了，或者我忘了什么，请告诉我

编辑：我想做的“事情”真的是标准的吗？

编辑2：已解决。见下面我的答案

学生/student.h：

#ifndef STUDENT_H
#define STUDENT_H

#define IDSIZE 7 + 1 // 7x char + '\0' terminator

typedef enum gender {
    MALE = 'M',
    FEMALE = 'F',
    OTHER = 'O'
} gender_t;

typedef struct date {
    short day;
    short month;
    int year;
} date_t;

typedef struct person {
    char *firstname;
    char *lastname;
    date_t birthdate;
    gender_t gender;
} person_t;

typedef struct student {
    char id[IDSIZE];

    struct person; // "extends" from struct person
} student_t;

#endif

/**
 * Trying to refactor the student crazy shit stuff of a previous exercise.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "student/student.h"

void die(const char * format, ...);

int main(int argc, char **argv) {
    if (argc < 2)
        die("Usage: %s inputfile.txt\n", argv[0]);

    puts("Ok");

    student_t student = {
        .id = "s184728",
        .firstname = "Tommaso",
        .lastname = "Ricci",
        .birthdate = {
            .day = 10,
            .month = 7,
            .year = 1992
        },
        .gender = MALE
    };

    return EXIT_SUCCESS;
}

void die(const char *format, ...) {
    va_list args;
    va_start (args, format);

    vfprintf(stderr, format, args);

    va_end (args);
    exit(EXIT_FAILURE);
}

NAME= es3
BIN= bin
SRC= src
EXE:= $(BIN)/$(NAME)
INPUT= input.txt

#RM=rm -rf
#CC=gcc

OBJS:= $(BIN)/$(NAME).o
FLAGS= -std=c11 -Wall -Wextra -pedantic

all: $(EXE)
$(EXE): $(OBJS)
    $(CC) $(FLAGS) $(OBJS) -o $(EXE)

$(BIN)/$(NAME).o: $(SRC)/$(NAME).c
    $(CC) $(FLAGS) -c $(SRC)/$(NAME).c -o $(BIN)/$(NAME).o

.PHONY: clean
clean:
    $(RM) $(EXE) $(OBJS)

.PHONY: run
run: $(EXE)
    @$(EXE) $(INPUT)

$ make
cc -std=c11 -Wall -Wextra -pedantic -c src/es3.c -o bin/es3.o
src/es3.c: In function ‘main’:
src/es3.c:22:9: warning: missing initializer for field ‘lastname’ of ‘struct person’ [-Wmissing-field-initializers]
         .lastname = "Ricci",
         ^
In file included from src/es3.c:9:0:
src/student/student.h:20:8: note: ‘lastname’ declared here
  char *lastname;
        ^
src/es3.c:23:9: warning: missing initializer for field ‘birthdate’ of ‘struct person’ [-Wmissing-field-initializers]
         .birthdate = {
         ^
In file included from src/es3.c:9:0:
src/student/student.h:21:9: note: ‘birthdate’ declared here
  date_t birthdate;
         ^
src/es3.c:28:9: warning: missing initializer for field ‘gender’ of ‘struct person’ [-Wmissing-field-initializers]
         .gender = MALE
         ^
In file included from src/es3.c:9:0:
src/student/student.h:22:11: note: ‘gender’ declared here
  gender_t gender;
           ^
src/es3.c:19:15: warning: unused variable ‘student’ [-Wunused-variable]
     student_t student = {
               ^
cc -std=c11 -Wall -Wextra -pedantic bin/es3.o -o bin/es3

es3.c：

#ifndef STUDENT_H
#define STUDENT_H

#define IDSIZE 7 + 1 // 7x char + '\0' terminator

typedef enum gender {
    MALE = 'M',
    FEMALE = 'F',
    OTHER = 'O'
} gender_t;

typedef struct date {
    short day;
    short month;
    int year;
} date_t;

typedef struct person {
    char *firstname;
    char *lastname;
    date_t birthdate;
    gender_t gender;
} person_t;

typedef struct student {
    char id[IDSIZE];

    struct person; // "extends" from struct person
} student_t;

#endif

/**
 * Trying to refactor the student crazy shit stuff of a previous exercise.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "student/student.h"

void die(const char * format, ...);

int main(int argc, char **argv) {
    if (argc < 2)
        die("Usage: %s inputfile.txt\n", argv[0]);

    puts("Ok");

    student_t student = {
        .id = "s184728",
        .firstname = "Tommaso",
        .lastname = "Ricci",
        .birthdate = {
            .day = 10,
            .month = 7,
            .year = 1992
        },
        .gender = MALE
    };

    return EXIT_SUCCESS;
}

void die(const char *format, ...) {
    va_list args;
    va_start (args, format);

    vfprintf(stderr, format, args);

    va_end (args);
    exit(EXIT_FAILURE);
}

NAME= es3
BIN= bin
SRC= src
EXE:= $(BIN)/$(NAME)
INPUT= input.txt

#RM=rm -rf
#CC=gcc

OBJS:= $(BIN)/$(NAME).o
FLAGS= -std=c11 -Wall -Wextra -pedantic

all: $(EXE)
$(EXE): $(OBJS)
    $(CC) $(FLAGS) $(OBJS) -o $(EXE)

$(BIN)/$(NAME).o: $(SRC)/$(NAME).c
    $(CC) $(FLAGS) -c $(SRC)/$(NAME).c -o $(BIN)/$(NAME).o

.PHONY: clean
clean:
    $(RM) $(EXE) $(OBJS)

.PHONY: run
run: $(EXE)
    @$(EXE) $(INPUT)

$ make
cc -std=c11 -Wall -Wextra -pedantic -c src/es3.c -o bin/es3.o
src/es3.c: In function ‘main’:
src/es3.c:22:9: warning: missing initializer for field ‘lastname’ of ‘struct person’ [-Wmissing-field-initializers]
         .lastname = "Ricci",
         ^
In file included from src/es3.c:9:0:
src/student/student.h:20:8: note: ‘lastname’ declared here
  char *lastname;
        ^
src/es3.c:23:9: warning: missing initializer for field ‘birthdate’ of ‘struct person’ [-Wmissing-field-initializers]
         .birthdate = {
         ^
In file included from src/es3.c:9:0:
src/student/student.h:21:9: note: ‘birthdate’ declared here
  date_t birthdate;
         ^
src/es3.c:28:9: warning: missing initializer for field ‘gender’ of ‘struct person’ [-Wmissing-field-initializers]
         .gender = MALE
         ^
In file included from src/es3.c:9:0:
src/student/student.h:22:11: note: ‘gender’ declared here
  gender_t gender;
           ^
src/es3.c:19:15: warning: unused variable ‘student’ [-Wunused-variable]
     student_t student = {
               ^
cc -std=c11 -Wall -Wextra -pedantic bin/es3.o -o bin/es3

每个变量的初始值设定项都存在，但仍然表示

缺少初始值设定项

gcc输出：

#ifndef STUDENT_H
#define STUDENT_H

#define IDSIZE 7 + 1 // 7x char + '\0' terminator

typedef enum gender {
    MALE = 'M',
    FEMALE = 'F',
    OTHER = 'O'
} gender_t;

typedef struct date {
    short day;
    short month;
    int year;
} date_t;

typedef struct person {
    char *firstname;
    char *lastname;
    date_t birthdate;
    gender_t gender;
} person_t;

typedef struct student {
    char id[IDSIZE];

    struct person; // "extends" from struct person
} student_t;

#endif

/**
 * Trying to refactor the student crazy shit stuff of a previous exercise.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "student/student.h"

void die(const char * format, ...);

int main(int argc, char **argv) {
    if (argc < 2)
        die("Usage: %s inputfile.txt\n", argv[0]);

    puts("Ok");

    student_t student = {
        .id = "s184728",
        .firstname = "Tommaso",
        .lastname = "Ricci",
        .birthdate = {
            .day = 10,
            .month = 7,
            .year = 1992
        },
        .gender = MALE
    };

    return EXIT_SUCCESS;
}

void die(const char *format, ...) {
    va_list args;
    va_start (args, format);

    vfprintf(stderr, format, args);

    va_end (args);
    exit(EXIT_FAILURE);
}

NAME= es3
BIN= bin
SRC= src
EXE:= $(BIN)/$(NAME)
INPUT= input.txt

#RM=rm -rf
#CC=gcc

OBJS:= $(BIN)/$(NAME).o
FLAGS= -std=c11 -Wall -Wextra -pedantic

all: $(EXE)
$(EXE): $(OBJS)
    $(CC) $(FLAGS) $(OBJS) -o $(EXE)

$(BIN)/$(NAME).o: $(SRC)/$(NAME).c
    $(CC) $(FLAGS) -c $(SRC)/$(NAME).c -o $(BIN)/$(NAME).o

.PHONY: clean
clean:
    $(RM) $(EXE) $(OBJS)

.PHONY: run
run: $(EXE)
    @$(EXE) $(INPUT)

$ make
cc -std=c11 -Wall -Wextra -pedantic -c src/es3.c -o bin/es3.o
src/es3.c: In function ‘main’:
src/es3.c:22:9: warning: missing initializer for field ‘lastname’ of ‘struct person’ [-Wmissing-field-initializers]
         .lastname = "Ricci",
         ^
In file included from src/es3.c:9:0:
src/student/student.h:20:8: note: ‘lastname’ declared here
  char *lastname;
        ^
src/es3.c:23:9: warning: missing initializer for field ‘birthdate’ of ‘struct person’ [-Wmissing-field-initializers]
         .birthdate = {
         ^
In file included from src/es3.c:9:0:
src/student/student.h:21:9: note: ‘birthdate’ declared here
  date_t birthdate;
         ^
src/es3.c:28:9: warning: missing initializer for field ‘gender’ of ‘struct person’ [-Wmissing-field-initializers]
         .gender = MALE
         ^
In file included from src/es3.c:9:0:
src/student/student.h:22:11: note: ‘gender’ declared here
  gender_t gender;
           ^
src/es3.c:19:15: warning: unused variable ‘student’ [-Wunused-variable]
     student_t student = {
               ^
cc -std=c11 -Wall -Wextra -pedantic bin/es3.o -o bin/es3

如果我理解正确，

：

符号已过时

我正在

Cygwin64

上使用

gcc版本4.9.3（gcc）

我发现了可能的相关问题，但没有解决我的问题：

指出：
类型说明符为不带标记的结构说明符的未命名成员称为匿名结构；类型说明符为不带标记的联合说明符的未命名成员称为匿名联合。匿名结构或联合的成员被视为包含结构或联合的成员。如果包含的结构或联合也是匿名的，则递归地应用
看来我们都误读了这一点（谢谢Dror K指出这一点）。代码的无标记版本应如下所示：

typedef struct student {
    char id[IDSIZE];

    struct { // <--- note the lack of tag here <---
        char *firstname;
        char *lastname;
        date_t birthdate;
        gender_t gender;
    };
} student_t;

typedef结构学生{
字符id[IDSIZE]；
struct{/解决了更改头代码的问题

我试图做的不是标准的，而是特定于
gcc
（我想）的实现

这段代码现在正在运行，不再出现初始化器错误：

#ifndef STUDENT_H
#define STUDENT_H

#define IDSIZE 7 + 1 // 7x char + '\0' terminator

typedef enum gender {
    MALE = 'M',
    FEMALE = 'F',
    OTHER = 'O'
} gender_t;

typedef struct date {
    short day;
    short month;
    int year;
} date_t;

typedef struct student {
    char id[IDSIZE];
    char *firstname;
    char *lastname;
    date_t birthdate;
    gender_t gender;
} student_t;

#endif

另请参见此处的
GCC
参考资料：
刚刚在普通Windows上试用了
MinGW
，并且刚刚收到关于未使用的variable@Seb您的引用声明：“…其类型说明符是不带标记的结构说明符…”-据我所知，他的结构有一个标记？但是如果我在Windows上运行makefile，
cmd
/
MinGW
我会得到一个链接器错误LOL@DrorK.你是对的……我不知道我是怎么误读的（好吧，事实上，我是这样认为的……深夜会让我们中最好的人变得愚蠢）。谢谢！：）那么，我没有使用标准功能？：p您的原始代码没有问题。使用
gcc-std=c11-pedantic errors-Wall-Wextra
编译就可以了。请注意，当涉及到指定的初始值设定项时，这是gcc中的一个缺陷/错误。我以前编写的只是一个gcc扩展，如果它不可移植，我就不这么做了我想使用它。但我同意，如果GCC支持，它不应该给出警告当你说-std=c11-pedantic时，你要求它不支持非标准扩展。你不可能两种方式都有。