c代码的编译过程（其中的图很有用哦）

下面的流程分别表示：

 .c文件经过预处理（gcc 时带上 -E选项）产生.i文件……

 

 

 

      预处理        编译          汇编              连接

.c------------>.i------------>.s------------>.o------------>a.out

       -E            -S            -c               

                        过程图

                       

[实例] 注意define和const的区别

#define MAX 2048

int main(void)

{

    const int max = 1024;

    char s1[MAX] = "abc";

    int i = max * 2;

    printf("%s\n", s1);

    printf("%d\n", i);

}

~                                                                                                               

"gcc.c" 9L, 142C

eleven@linux:~> gcc -E gcc.c

# 1 "gcc.c"

# 1 ""

# 1 ""

# 1 "gcc.c"

 

int main(void)

{

        const int max = 1024;

        char s1[2048] = "abc";

        int i = max * 2;

        printf("%s\n", s1);

        printf("%d\n", i);

}

eleven@linux:~> gcc -S gcc.c

eleven@linux:~> ls

  gcc.c  gcc.s 

eleven@linux:~> cat gcc.s

        .file   "gcc.c"

        .section        .rodata

.LC0:

        .string "abc"

        .zero   2044

.LC1:

        .string "%s\n"

.LC2:

        .string "%d\n"

        .text

.globl main

        .type   main, @function

main:

        pushl   %ebp

        movl    %esp, %ebp

        pushl   %edi

        subl    $2084, %esp

        andl    $-16, %esp

        movl    $0, %eax

        addl    $15, %eax

        addl    $15, %eax

        shrl    $4, %eax

        sall    $4, %eax

        subl    %eax, %esp

        movl    $1024, -12(%ebp)

        movl    .LC0, %eax

        movl    %eax, -2072(%ebp)

        leal    -2068(%ebp), %edi

        cld

        movl    $0, %edx

        movl    $511, %eax

        movl    %eax, %ecx

        movl    %edx, %eax

        rep

        stosl

        movl    -12(%ebp), %eax

        addl    %eax, %eax

        movl    %eax, -2076(%ebp)

        subl    $8, %esp

        leal    -2072(%ebp), %eax

        pushl   %eax

        pushl   $.LC1

        call    printf

        addl    $16, %esp

        subl    $8, %esp

        pushl   -2076(%ebp)

        pushl   $.LC2

        call    printf

        addl    $16, %esp

        movl    -4(%ebp), %edi

        leave

        ret

        .size   main, .-main

        .section        .note.GNU-stack,"",@progbits

        .ident  "GCC: (GNU) 3.3.3 (SuSE Linux)"

 

eleven@linux:~> ls

gcc.c  gcc.s 

eleven@linux:~> gcc gcc.c

eleven@linux:~> ls

a.out gcc.c  gcc.s

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