Gccgo在go中传递和修改C结构时出错

我试图将一个go库转换为由C调用的库，我从一个简单的测试（基于我发现的有效文件）开始，但当我尝试构建时，会出现错误。我尝试将C中的一个结构传递给一个go函数，该函数使用该结构中的数据并返回一个值（在本例中是一个整数，但最终它将是另一个结构）

Go版本：1.4.2

gccgo版本：5.0.1

gcc版本：4.9.2

h型

typedef struct num {
    int n;
} num;

foo.go

package main

// #include "type.h"
import "C"

func New(x int) C.struct_num {
    num := C.struct_num{}
    num.n = C.int(x)
    return num
}

func Add(num C.struct_num, x int) int {
    return int(num.n) + x
}

酒吧c

当我运行make时，我得到错误信息：

gcc foo.o bar.c -o main
foo.o:(.rodata.__go_td_pN23_example.main._Ctype_int[__go_td_pN23_example.main._Ctype_int]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN23_example.main._Ctype_int[__go_td_pN23_example.main._Ctype_int]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_int+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_int+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_td_pN30_example.main._Ctype_struct_num[__go_td_pN30_example.main._Ctype_struct_num]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN30_example.main._Ctype_struct_num[__go_td_pN30_example.main._Ctype_struct_num]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_struct_num+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_struct_num+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_td_pN24_example.main._Ctype_void[__go_td_pN24_example.main._Ctype_void]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN24_example.main._Ctype_void[__go_td_pN24_example.main._Ctype_void]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_void+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_void+0x20): undefined reference to `__go_type_equal_identity'
collect2: error: ld returned 1 exit status
Makefile:4: recipe for target 'main' failed
make: *** [main] Error 1

根据我从其他搜索中了解到的情况，这些错误与对C go库的调用有关，表明这可能没有被编译到对象文件中。我也尝试过在make文件中直接运行gccgo，结果相同。感谢您的任何见解和/或帮助。谢谢

编辑

---

多亏了你，我才明白这一点。显然，我需要在Makefile中为main调用gccgo，因为gcc不知道如何正确链接go运行时。

从未使用过gccgo。有没有更好/不同的方法来编译go模块以链接到C项目中？据我所知，使用go命令倾向于只编译可运行的二进制文件，其中go是程序的入口点并运行C代码，而不是相反。我读过其他（旧）帖子，提到go需要go运行时，但显然在使用go构建时必须将其打包到二进制文件中，因为它可以在没有安装go的相同体系结构的机器上运行，所以至少在这种情况下，必须在二进制文件中包含必要的运行时组件。从未使用过gccgo。有没有更好/不同的方法来编译go模块以链接到C项目中？据我所知，使用go命令倾向于只编译可运行的二进制文件，其中go是程序的入口点并运行C代码，而不是相反。我读过其他（旧的）帖子，提到go需要go运行时，但显然，在使用go构建时，这必须打包到二进制文件中，因为它可以在没有安装go的相同体系结构的机器上运行，所以至少在这个用例中，二进制文件中必须包含必要的运行时组件。

all: main

main: foo.o bar.c
    gcc foo.o bar.c -o main

foo.o: foo.go
    go build -compiler gccgo -gccgoflags '-c -o foo.o -fgo-prefix=example' foo.go

clean:
    rm -f main *.o

gcc foo.o bar.c -o main
foo.o:(.rodata.__go_td_pN23_example.main._Ctype_int[__go_td_pN23_example.main._Ctype_int]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN23_example.main._Ctype_int[__go_td_pN23_example.main._Ctype_int]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_int+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_int+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_td_pN30_example.main._Ctype_struct_num[__go_td_pN30_example.main._Ctype_struct_num]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN30_example.main._Ctype_struct_num[__go_td_pN30_example.main._Ctype_struct_num]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_struct_num+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_struct_num+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_td_pN24_example.main._Ctype_void[__go_td_pN24_example.main._Ctype_void]+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_td_pN24_example.main._Ctype_void[__go_td_pN24_example.main._Ctype_void]+0x20): undefined reference to `__go_type_equal_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_void+0x18): undefined reference to `__go_type_hash_identity'
foo.o:(.rodata.__go_tdn_example.main..example_main._Ctype_void+0x20): undefined reference to `__go_type_equal_identity'
collect2: error: ld returned 1 exit status
Makefile:4: recipe for target 'main' failed
make: *** [main] Error 1