链接错误在Ubuntu使用gcc 11.10

Question

我试图编译和运行C一个简单的“Hello World”程序，我得到的一些C STDLIB功能

的.C多重定义的奇怪的错误 文件是：

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

int main(int argc, char **argv) { 

    printf("hello world\n"); 
    return 0; 
} 

我用它来编译和创建可执行的命令是：

gcc -Werror -Wall src/main.c -o bin/m.o 
gcc -Werror -Wall bin/m.o -o bin/m 

编译部分去罚款，但在第二个命令，我在那里调用GCC链接 创建可执行我收到以下错误：

bin/m.o: In function `_fini': 
(.fini+0x0): multiple definition of `_fini' 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crti.o:(.fini+0x0): first defined here 
bin/m.o: In function `__data_start': 
(.data+0x0): multiple definition of `__data_start' 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 10 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 1 has invalid symbol index 11 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 2 has invalid symbol index 2 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 3 has invalid symbol index 2 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 4 has invalid symbol index 10 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 5 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 6 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 7 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 8 has invalid symbol index 2 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 9 has invalid symbol index 2 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 10 has invalid symbol index 11 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 11 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 12 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 13 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 14 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 15 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 16 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 17 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 18 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 19 has invalid symbol index 12 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 20 has invalid symbol index 19 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:(.data+0x0): first defined here 
bin/m.o: In function `__data_start': 
(.data+0x8): multiple definition of `__dso_handle' 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/crtbegin.o:(.data+0x0): first defined here 
bin/m.o:(.rodata+0x0): multiple definition of `_IO_stdin_used' 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:    (.rodata.cst4+0x0): first defined here 
bin/m.o: In function `_start': 
(.text+0x0): multiple definition of `_start' 
/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_line): relocation 0 has invalid symbol index 2 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crt1.o:/build/buildd /eglibc-2.13/csu/../sysdeps/x86_64/elf/start.S:109: first defined here 
bin/m.o: In function `_init': 
(.init+0x0): multiple definition of `_init' 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/../../../x86_64-linux-gnu/crti.o:(.init+0x0): first  defined here 
/usr/lib/gcc/x86_64-linux-gnu/4.6.1/crtend.o:(.dtors+0x0): multiple definition of  `__DTOR_END__' 
bin/m.o:(.dtors+0x8): first defined here 
/usr/bin/ld: error in bin/m.o(.eh_frame); no .eh_frame_hdr table will be created. 
collect2: ld returned 1 exit status 

顺便说一下，当我运行bash的执行前缀莫文件，它工作得很好

在C从不程序性或者任何东西，我试着开始，但是这让我想起

Answer 1

您需要编译步骤中的-c，否则您的m.o对象将是完全链接的可执行文件。例如：

gcc -Werror -Wall -c src/main.c -o bin/m.o 
gcc -Werror -Wall bin/m.o -o bin/m 

如果你的程序是由的不仅仅是单一的翻译单元更多的差别是显而易见。如果你有file1.c和file2.c，例如：

gcc -c file1.c -o file1.o 
gcc -c file2.c -o file2.o 
gcc file1.o file2.o -o app 

是正确的，而如果你有：

gcc file1.c -o file1.o 
gcc file2.c -o file2.o 
gcc file1.o file2.o -o app 

两个之前，你甚至搞到最后链接阶段的第一行和第二行会失败，因为他们会丢失符号。

Answer 2

gcc -Werror -Wall src/main.c -o bin/m.o 
gcc -Werror -Wall bin/m.o -o bin/m 

第一个省略了-c选项，所以它创建了一个完全链接的可执行文件。 ELF对象的一个​​特点是可执行文件和目标文件之间没有显着差异，因此它对于另一个ld运行是完全有效的输入 - 但是然后您将链接到完整程序中的符号与要链接的符号冲突进入新的一个。

课：只做编译时使用gcc -c

gcc -Werror -Wall -c src/main.c -o bin/m.o # this needs -c so it only compiles 
gcc -Werror -Wall bin/m.o -o bin/m   # this links, so no -c