How to understand the output of gcc -S *.cpp?

Posted by user198729 on Stack Overflow See other posts from Stack Overflow or by user198729
Published on 2010-03-29T03:07:27Z Indexed on 2010/03/29 3:13 UTC
Read the original article Hit count: 388

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A sample one as follows:

    .file   "hw.cpp"
    .section .rdata,"dr"
LC0:
    .ascii "Oh shit really bad~!\15\12\0"
    .text
    .align 2
.globl __Z3badv
    .def    __Z3badv;   .scl    2;  .type   32; .endef
__Z3badv:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $8, %esp
    movl    $LC0, (%esp)
    call    _printf
    leave
    ret
    .section .rdata,"dr"
LC1:
    .ascii "WOW\0"
    .text
    .align 2
.globl __Z3foov
    .def    __Z3foov;   .scl    2;  .type   32; .endef
__Z3foov:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $4, %esp
    movl    LC1, %eax
    movl    %eax, -4(%ebp)
    movl    $__Z3badv, 4(%ebp)
    leave
    ret
    .def    ___main;    .scl    2;  .type   32; .endef
    .align 2
.globl _main
    .def    _main;  .scl    2;  .type   32; .endef
_main:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $8, %esp
    andl    $-16, %esp
    movl    $0, %eax
    addl    $15, %eax
    addl    $15, %eax
    shrl    $4, %eax
    sall    $4, %eax
    movl    %eax, -4(%ebp)
    movl    -4(%ebp), %eax
    call    __alloca
    call    ___main
    call    __Z3foov
    movl    $0, %eax
    leave
    ret
    .def    _printf;    .scl    2;  .type   32; .endef

Has anyone tried to understand it?

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