执行由Numba生成的程序集

2024-09-30 04:34:58 发布

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在一个奇怪的情况下,我陷入了以下困境,我使用以下Python代码将Numba生成的程序集写入文件:

@jit(nopython=True, nogil=True)
def six():
    return 6

with open("six.asm", "w") as f:
    for k, v in six.inspect_asm().items():
        f.write(v)

汇编代码已成功写入该文件,但我不知道如何执行它。我尝试了以下方法:

$ as -o six.o six.asm
$ ld six.o -o six.bin
$ chmod +x six.bin
$ ./six.bin

但是,链接步骤失败,原因如下:

ld: warning: cannot find entry symbol _start; defaulting to 00000000004000f0
six.o: In function `cpython::__main__::six$241':
<string>:(.text+0x20): undefined reference to `PyArg_UnpackTuple'
<string>:(.text+0x47): undefined reference to `PyEval_SaveThread'
<string>:(.text+0x53): undefined reference to `PyEval_RestoreThread'
<string>:(.text+0x62): undefined reference to `PyLong_FromLongLong'
<string>:(.text+0x74): undefined reference to `PyExc_RuntimeError'
<string>:(.text+0x88): undefined reference to `PyErr_SetString'

我怀疑Numba和/或Python标准库需要与生成的对象文件进行动态链接才能成功运行,但我不确定该如何实现(如果一开始就可以实现的话)

我还尝试了以下方法,将中间LLVM代码写入文件而不是程序集:

with open("six.ll", "w") as f:
    for k, v in six.inspect_llvm().items():
        f.write(v)

然后

$ lli six.ll

但这也会失败,并出现以下错误:

'main' function not found in module.

更新:

事实证明,存在一个实用程序来查找要传递给ld命令的相关标志,以动态链接Python标准库

$ python3-config --ldflags

返回

-L/Users/rayan/anaconda3/lib/python3.7/config-3.7m-darwin -lpython3.7m -ldl -framework CoreFoundation 

再次运行以下命令,这次使用正确的标志:

$ as -o six.o six.asm
$ ld six.o -o six.bin -L/Users/rayan/anaconda3/lib/python3.7/config-3.7m-darwin -lpython3.7m -ldl -framework CoreFoundation 
$ chmod +x six.bin
$ ./six.bin

我现在越来越紧张了

ld: warning: No version-min specified on command line
ld: entry point (_main) undefined. for inferred architecture x86_64

我曾尝试在程序集文件中添加_main标签,但似乎没有任何效果。关于如何定义入口点有什么想法吗

更新2:

下面是有用的汇编代码,目标函数似乎是带有标签_ZN8__main__7six$241E的函数:

    .text
    .file   "<string>"
    .globl  _ZN8__main__7six$241E
    .p2align    4, 0x90
    .type   _ZN8__main__7six$241E,@function
_ZN8__main__7six$241E:
    movq    $6, (%rdi)
    xorl    %eax, %eax
    retq
.Lfunc_end0:
    .size   _ZN8__main__7six$241E, .Lfunc_end0-_ZN8__main__7six$241E

    .globl  _ZN7cpython8__main__7six$241E
    .p2align    4, 0x90
    .type   _ZN7cpython8__main__7six$241E,@function
_ZN7cpython8__main__7six$241E:
    .cfi_startproc
    pushq   %rax
    .cfi_def_cfa_offset 16
    movq    %rsi, %rdi
    movabsq $.const.six, %rsi
    movabsq $PyArg_UnpackTuple, %r8
    xorl    %edx, %edx
    xorl    %ecx, %ecx
    xorl    %eax, %eax
    callq   *%r8
    testl   %eax, %eax
    je  .LBB1_3
    movabsq $_ZN08NumbaEnv8__main__7six$241E, %rax
    cmpq    $0, (%rax)
    je  .LBB1_2
    movabsq $PyEval_SaveThread, %rax
    callq   *%rax
    movabsq $PyEval_RestoreThread, %rcx
    movq    %rax, %rdi
    callq   *%rcx
    movabsq $PyLong_FromLongLong, %rax
    movl    $6, %edi
    popq    %rcx
    .cfi_def_cfa_offset 8
    jmpq    *%rax
.LBB1_2:
    .cfi_def_cfa_offset 16
    movabsq $PyExc_RuntimeError, %rdi
    movabsq $".const.missing Environment", %rsi
    movabsq $PyErr_SetString, %rax
    callq   *%rax
.LBB1_3:
    xorl    %eax, %eax
    popq    %rcx
    .cfi_def_cfa_offset 8
    retq
.Lfunc_end1:
    .size   _ZN7cpython8__main__7six$241E, .Lfunc_end1-_ZN7cpython8__main__7six$241E
    .cfi_endproc

    .globl  cfunc._ZN8__main__7six$241E
    .p2align    4, 0x90
    .type   cfunc._ZN8__main__7six$241E,@function
cfunc._ZN8__main__7six$241E:
    movl    $6, %eax
    retq
.Lfunc_end2:
    .size   cfunc._ZN8__main__7six$241E, .Lfunc_end2-cfunc._ZN8__main__7six$241E

    .type   _ZN08NumbaEnv8__main__7six$241E,@object
    .comm   _ZN08NumbaEnv8__main__7six$241E,8,8
    .type   .const.six,@object
    .section    .rodata,"a",@progbits
.const.six:
    .asciz  "six"
    .size   .const.six, 4

    .type   ".const.missing Environment",@object
    .p2align    4
.const.missing Environment:
    .asciz  "missing Environment"
    .size   ".const.missing Environment", 20


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

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1条回答
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1楼 · 发布于 2024-09-30 04:34:58

在浏览了[PyData.Numba]: Numbadocs,以及一些调试、尝试和错误之后,我得出了一个结论:看来你已经偏离了追求的道路(评论中也指出了这一点)

NumbaPython代码(函数)转换为机器代码(原因很明显:速度)。它可以在运行过程中执行所有操作(转换、构建、插入),程序员只需将函数修饰为,例如@numba.jit[PyData.Numba]: Just-in-Time compilation

你所经历的行为是正确的。Dispatcher对象(用于修饰six函数)只为函数本身生成(汇编)代码(它不在那里,因为代码在当前进程中执行(Python解释器的main函数))。因此,链接器抱怨没有main符号是正常的。这就像编写一个只包含以下内容的C文件:

int six() {
    return 6;
}

为了使事情正常运行,您必须:

  1. .asm文件构建到.o(对象)文件中(完成)

  2. 包括#1中的.o文件进入一个可以

    • 静止的
    • 动态的


    该库将链接到(最终)可执行文件中。此步骤是可选的,因为您可以直接使用.o文件

  3. 将另一个定义main的文件(并调用six——我认为这就是全部目的)构建到一个.o文件中。因为我对汇编不是很熟悉,所以我在C

  4. 将两个实体(从#2.#1.)和#3.)链接在一起

作为替代方案,您可以查看[PyData.Numba]: Compiling code ahead of time,但请记住,它将生成一个Python(扩展)模块

回到当前的问题。在Ubuntu 18.04 64位上进行了测试

code00.py

#!/usr/bin/env python

import sys
import math
import numba


@numba.jit(nopython=True, nogil=True)
def six():
    return 6


def main(*argv):
    six()  # Call the function(s), otherwise `inspect_asm()` would return empty dict
    speed_funcs = [
        (six, numba.int32()),
    ]
    for func, _ in speed_funcs:
        file_name_asm = "numba_{0:s}_{1:s}_{2:03d}_{3:02d}{4:02d}{5:02d}.asm".format(func.__name__, sys.platform, int(round(math.log2(sys.maxsize))) + 1, *sys.version_info[:3])
        asm = func.inspect_asm()
        print("Writing to {0:s}:".format(file_name_asm))
        with open(file_name_asm, "wb") as fout:
            for k, v in asm.items():
                print("    {0:}".format(k))
                fout.write(v.encode())


if __name__ == "__main__":
    print("Python {0:s} {1:d}bit on {2:s}\n".format(" ".join(item.strip() for item in sys.version.split("\n")), 64 if sys.maxsize > 0x100000000 else 32, sys.platform))
    main(*sys.argv[1:])
    print("\nDone.")

main00.c

#include <stdio.h>
#include <dlfcn.h>

//#define SYMBOL_SIX "_ZN8__main__7six$241E"
#define SYMBOL_SIX "cfunc._ZN8__main__7six$241E"

typedef int (*SixFuncPtr)();

int main() {
    void *pMod = dlopen("./libnumba_six_linux.so", RTLD_LAZY);
    if (!pMod) {
        printf("Error (%s) loading module\n", dlerror());
        return -1;
    }
    SixFuncPtr pSixFunc = dlsym(pMod, SYMBOL_SIX);
    if (!pSixFunc)
    {
        printf("Error (%s) loading function\n", dlerror());
        dlclose(pMod);
         return -2;
    }
    printf("six() returned: %d\n", (*pSixFunc)());
    dlclose(pMod);
    return 0;
}

build.sh

CC=gcc

LIB_BASE_NAME=numba_six_linux

FLAG_LD_LIB_NUMBALINUX="-Wl,-L. -Wl,-l${LIB_BASE_NAME}"
FLAG_LD_LIB_PYTHON="-Wl,-L/usr/lib/python3.7/config-3.7m-x86_64-linux-gnu -Wl,-lpython3.7m"

rm -f *.asm *.o *.a *.so *.exe

echo Generate .asm
python3 code00.py

echo Assemble
as -o ${LIB_BASE_NAME}.o ${LIB_BASE_NAME}_064_030705.asm

echo Link library
LIB_NUMBA="./lib${LIB_BASE_NAME}.so"
#ar -scr ${LIB_NUMBA} ${LIB_BASE_NAME}.o
${CC} -o ${LIB_NUMBA} -shared ${LIB_BASE_NAME}.o ${FLAG_LD_LIB_PYTHON}

echo Dump library contents
nm -S ${LIB_NUMBA}
#objdump -t ${LIB_NUMBA}

echo Compile and link executable
${CC} -o main00.exe main00.c -ldl

echo Exit script

输出

(py_venv_pc064_03.07.05_test0) [cfati@cfati-ubtu-18-064-00:~/Work/Dev/StackOverflow/q061678226]> ~/sopr.sh
*** Set shorter prompt to better fit when pasted in StackOverflow (or other) pages ***

[064bit prompt]>
[064bit prompt]> ls
build.sh  code00.py  main00.c
[064bit prompt]>
[064bit prompt]> ./build.sh
Generate .asm
Python 3.7.5 (default, Nov  7 2019, 10:50:52) [GCC 8.3.0] 64bit on linux

Writing to numba_six_linux_064_030705.asm:
    ()

Done.
Assemble
Link library
Dump library contents
0000000000201020 B __bss_start
00000000000008b0 0000000000000006 T cfunc._ZN8__main__7six$241E
0000000000201020 0000000000000001 b completed.7698
00000000000008e0 0000000000000014 r .const.missing Environment
00000000000008d0 0000000000000004 r .const.six
                 w __cxa_finalize
0000000000000730 t deregister_tm_clones
00000000000007c0 t __do_global_dtors_aux
0000000000200e58 t __do_global_dtors_aux_fini_array_entry
0000000000201018 d __dso_handle
0000000000200e60 d _DYNAMIC
0000000000201020 D _edata
0000000000201030 B _end
00000000000008b8 T _fini
0000000000000800 t frame_dummy
0000000000200e50 t __frame_dummy_init_array_entry
0000000000000990 r __FRAME_END__
0000000000201000 d _GLOBAL_OFFSET_TABLE_
                 w __gmon_start__
00000000000008f4 r __GNU_EH_FRAME_HDR
00000000000006f0 T _init
                 w _ITM_deregisterTMCloneTable
                 w _ITM_registerTMCloneTable
                 U PyArg_UnpackTuple
                 U PyErr_SetString
                 U PyEval_RestoreThread
                 U PyEval_SaveThread
                 U PyExc_RuntimeError
                 U PyLong_FromLongLong
0000000000000770 t register_tm_clones
0000000000201020 d __TMC_END__
0000000000201028 0000000000000008 B _ZN08NumbaEnv8__main__7six$241E
0000000000000820 0000000000000086 T _ZN7cpython8__main__7six$241E
0000000000000810 000000000000000a T _ZN8__main__7six$241E
Compile and link executable
Exit script
[064bit prompt]>
[064bit prompt]> ls
build.sh  code00.py  libnumba_six_linux.so  main00.c  main00.exe  numba_six_linux_064_030705.asm  numba_six_linux.o
[064bit prompt]>
[064bit prompt]> # Run the executable
[064bit prompt]>
[064bit prompt]> ./main00.exe
six() returned: 6
[064bit prompt]>

同时发布(因为它很重要)numba\u six\u linux\u 064\u 030705.asm

    .text
    .file   "<string>"
    .globl  _ZN8__main__7six$241E
    .p2align    4, 0x90
    .type   _ZN8__main__7six$241E,@function
_ZN8__main__7six$241E:
    movq    $6, (%rdi)
    xorl    %eax, %eax
    retq
.Lfunc_end0:
    .size   _ZN8__main__7six$241E, .Lfunc_end0-_ZN8__main__7six$241E

    .globl  _ZN7cpython8__main__7six$241E
    .p2align    4, 0x90
    .type   _ZN7cpython8__main__7six$241E,@function
_ZN7cpython8__main__7six$241E:
    .cfi_startproc
    pushq   %rax
    .cfi_def_cfa_offset 16
    movq    %rsi, %rdi
    movabsq $.const.six, %rsi
    movabsq $PyArg_UnpackTuple, %r8
    xorl    %edx, %edx
    xorl    %ecx, %ecx
    xorl    %eax, %eax
    callq   *%r8
    testl   %eax, %eax
    je  .LBB1_3
    movabsq $_ZN08NumbaEnv8__main__7six$241E, %rax
    cmpq    $0, (%rax)
    je  .LBB1_2
    movabsq $PyEval_SaveThread, %rax
    callq   *%rax
    movabsq $PyEval_RestoreThread, %rcx
    movq    %rax, %rdi
    callq   *%rcx
    movabsq $PyLong_FromLongLong, %rax
    movl    $6, %edi
    popq    %rcx
    .cfi_def_cfa_offset 8
    jmpq    *%rax
.LBB1_2:
    .cfi_def_cfa_offset 16
    movabsq $PyExc_RuntimeError, %rdi
    movabsq $".const.missing Environment", %rsi
    movabsq $PyErr_SetString, %rax
    callq   *%rax
.LBB1_3:
    xorl    %eax, %eax
    popq    %rcx
    .cfi_def_cfa_offset 8
    retq
.Lfunc_end1:
    .size   _ZN7cpython8__main__7six$241E, .Lfunc_end1-_ZN7cpython8__main__7six$241E
    .cfi_endproc

    .globl  cfunc._ZN8__main__7six$241E
    .p2align    4, 0x90
    .type   cfunc._ZN8__main__7six$241E,@function
cfunc._ZN8__main__7six$241E:
    movl    $6, %eax
    retq
.Lfunc_end2:
    .size   cfunc._ZN8__main__7six$241E, .Lfunc_end2-cfunc._ZN8__main__7six$241E

    .type   _ZN08NumbaEnv8__main__7six$241E,@object
    .comm   _ZN08NumbaEnv8__main__7six$241E,8,8
    .type   .const.six,@object
    .section    .rodata,"a",@progbits
.const.six:
    .asciz  "six"
    .size   .const.six, 4

    .type   ".const.missing Environment",@object
    .p2align    4
".const.missing Environment":
    .asciz  "missing Environment"
    .size   ".const.missing Environment", 20


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

注释

  • numba_six_linux_064_030705.asm(以及由此派生的所有内容)包含函数的代码。实际上,有一组符号(在OSX上,您也可以使用本机otool -T),如:

    1. cfunc.\u ZN8\u main\u 7six$241E-(C)函数本身

    2. \u ZN7cpython8\u main\u 7six$241E-Python包装器:

      1. 执行C<=&燃气轮机Python转换(通过pythonapi函数,如PyArg\u unpactuple
      2. 由于#1它需要(取决于)libpython3.7m
      3. 因此,nopython=True在这种情况下没有效果

    此外,这些符号中的main部分并不是指一个可执行的入口点(main函数),而是指一个Python模块的顶级名称空间(\uu main\uu。毕竟,这段代码应该是从Python

  • 由于C普通函数的名称中包含一个),我无法直接从C调用它(因为它是一个无效的标识符名称),所以我必须手动加载.so该函数(dlopen/dlsym),产生了比简单调用函数更多的代码
    我没有尝试,但我认为对生成的.asm文件进行以下(手动)更改可以简化工作:

    • 重命名普通的C函数名(类似于\uu-six或任何其他有效的C在汇编.asm文件之前,也不会与该文件中的另一个(显式或内部)名称冲突的标识符将使该函数可以从C直接调用
    • 移除Python包装器(#2.)也将摆脱#22


更新#0

感谢@PeterCordes,他分享了我丢失的那条信息([GNU.GCC]: Controlling Names Used in Assembler Code),这里有一个更简单的版本

main01.c

#include <stdio.h>

extern int six() asm ("cfunc._ZN8__main__7six$241E");

int main() {
    printf("six() returned: %d\n", six());
}

输出

[064bit prompt]> # Resume from previous point + main01.c
[064bit prompt]>
[064bit prompt]> ls
build.sh  code00.py  libnumba_six_linux.so  main00.c  main00.exe  main01.c  numba_six_linux_064_030705.asm  numba_six_linux.o
[064bit prompt]>
[064bit prompt]> ar -scr libnumba_six_linux.a numba_six_linux.o
[064bit prompt]>
[064bit prompt]> gcc -o main01.exe main01.c ./libnumba_six_linux.a -Wl,-L/usr/lib/python3.7/config-3.7m-x86_64-linux-gnu -Wl,-lpython3.7m
[064bit prompt]>
[064bit prompt]> ls
build.sh  code00.py  libnumba_six_linux.a  libnumba_six_linux.so  main00.c  main00.exe  main01.c  main01.exe  numba_six_linux_064_030705.asm  numba_six_linux.o
[064bit prompt]>
[064bit prompt]> ./main01.exe
six() returned: 6
[064bit prompt]>

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