在Matlab的MEX编译过程中如何链接 [英] How to link during Matlab's MEX compilation

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问题描述

我编写了以下形式的程序:

I've written a program of the following form:

#include "stuff_I_need.h"

int main(){

construct_array(); // uses OpenMP pragma's
print_array();

return(0);


}

使用以下命令正确编译，链接和运行:

that compiles, links, and runs correctly with the following command:

`gcc44 -I/home/matteson/sundials/include/ main.c -lm -L/home/matteson/sundials/lib -lsundials_cvode -lsundials_nvecserial -fopenmp -o /home/matteson/MPI_test/CVODE_test/main_test`

"gcc44"只是gcc版本4.4，因此命名为"gcc44"，因为它是在维护多个gcc版本的群集上编译的.数组构造过程中，使用sundials_cvode和sundials_nvecserial库来求解几个微分方程.

"gcc44" is simply gcc version 4.4 and is named like this because it's being compiled on a cluster that maintains several versions of gcc. The libraries sundials_cvode and sundials_nvecserial are used in the solving of several differential equations during the construction of the array.

现在，当我想转移到Matlab并尝试编译以下形式的mex文件时:

Now when I want to transfer over to Matlab and try to compile the mex file of the form:

#include "stuff_I_need.h"

void mexFunction(int nlhs,mxArray* plhs[], int nrhs, const mxArray* prhs[]){

construct_array(); // uses OpenMP pragma's
print_array();

}

并尝试在Matlab中使用以下命令进行编译:

and try to compile with the following command in Matlab:

>> mex -v CC="gcc44" CFLAGS="\$CFLAGS -I/home/matteson/sundials/include/ -fopenmp" LDFLAGS="\$LDFLAGS -fopenmp -L/home/matteson/sundials/lib -lsundials_cvode -lsundials_nvecserial" mex_cvode.c

我收到以下消息，最终导致链接错误:

I get the following messages culminating in a link error:

    -> mexopts.sh sourced from directory (DIR = $HOME/.matlab/$REL_VERSION)
   FILE = /home/matteson/.matlab/R2010b/mexopts.sh
----------------------------------------------------------------
->    MATLAB                = /misc/linux/64/opt/pkg/matlab/R2010b
->    CC                    = gcc44
->    CC flags:
         CFLAGS             = -ansi -D_GNU_SOURCE  -fexceptions -fPIC -fno-omit-frame-pointer -pthread -I/home/matteson/sundials/include/ -L/home/matteson/sundials/lib -lsundials_cvode -L/home/matteson/sundials/lib -lsundials_nvecserial
         CDEBUGFLAGS        = -g
         COPTIMFLAGS        = -O -DNDEBUG
         CLIBS              = -Wl,-rpath-link,/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -L/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -lmx -lmex -lmat -lm -lstdc++
         arguments          =  -DMX_COMPAT_32
->    CXX                   = g++
->    CXX flags:
         CXXFLAGS           = -ansi -D_GNU_SOURCE -fPIC -fno-omit-frame-pointer -pthread
         CXXDEBUGFLAGS      = -g
         CXXOPTIMFLAGS      = -O -DNDEBUG
         CXXLIBS            = -Wl,-rpath-link,/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -L/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -lmx -lmex -lmat -lm
         arguments          =  -DMX_COMPAT_32
->    FC                    = g95
->    FC flags:
         FFLAGS             = -fexceptions -fPIC -fno-omit-frame-pointer
         FDEBUGFLAGS        = -g
         FOPTIMFLAGS        = -O
         FLIBS              = -Wl,-rpath-link,/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -L/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -lmx -lmex -lmat -lm
         arguments          =  -DMX_COMPAT_32
->    LD                    = gcc44
->    Link flags:
         LDFLAGS            = -pthread -shared -Wl,--version-script,/misc/linux/64/opt/pkg/matlab/R2010b/extern/lib/glnxa64/mexFunction.map -Wl,--no-undefined -fopenmpofopenmp
         LDDEBUGFLAGS       = -g
         LDOPTIMFLAGS       = -O
         LDEXTENSION        = .mexa64
         arguments          = 
->    LDCXX                 = 
->    Link flags:
         LDCXXFLAGS         = 
         LDCXXDEBUGFLAGS    = 
         LDCXXOPTIMFLAGS    = 
         LDCXXEXTENSION     = 
         arguments          = 
----------------------------------------------------------------


Warning: You are using gcc version "4.4.4".  The version
         currently supported with MEX is "4.3.4".
         For a list of currently supported compilers see: 
         http://www.mathworks.com/support/compilers/current_release/

-> gcc44 -c  -I/misc/linux/64/opt/pkg/matlab/R2010b/extern/include -I/misc/linux/64/opt/pkg/matlab/R2010b/simulink/include -DMATLAB_MEX_FILE -ansi -D_GNU_SOURCE  -fexceptions -fPIC -fno-omit-frame-pointer -pthread -I/home/matteson/sundials/include/ -L/home/matteson/sundials/lib -lsundials_cvode -L/home/matteson/sundials/lib -lsundials_nvecserial  -DMX_COMPAT_32 -O -DNDEBUG  "mex_cvode.c"

-> gcc44 -O -pthread -shared -Wl,--version-script,/misc/linux/64/opt/pkg/matlab/R2010b/extern/lib/glnxa64/mexFunction.map -Wl,--no-undefined -fopenmpofopenmp -o  "mex_cvode.mexa64"  mex_cvode.o  -Wl,-rpath-link,/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -L/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -lmx -lmex -lmat -lm -lstdc++

mex_cvode.o: In function `mexFunction':
mex_cvode.c:(.text+0x2b2): undefined reference to `N_VNew_Serial'
mex_cvode.c:(.text+0x2db): undefined reference to `N_VNew_Serial'
mex_cvode.c:(.text+0x35b): undefined reference to `CVodeCreate'
mex_cvode.c:(.text+0x39c): undefined reference to `CVodeInit'
mex_cvode.c:(.text+0x3dd): undefined reference to `CVodeSVtolerances'
mex_cvode.c:(.text+0x412): undefined reference to `CVodeSetUserData'
mex_cvode.c:(.text+0x449): undefined reference to `CVDense'
mex_cvode.c:(.text+0x482): undefined reference to `CVDlsSetDenseJacFn'
mex_cvode.c:(.text+0x50c): undefined reference to `CVode'
mex_cvode.c:(.text+0x5b4): undefined reference to `N_VDestroy_Serial'
mex_cvode.c:(.text+0x5c0): undefined reference to `N_VDestroy_Serial'
mex_cvode.c:(.text+0x5cc): undefined reference to `CVodeFree'
collect2: ld returned 1 exit status

    mex: link of ' "mex_cvode.mexa64"' failed.

??? Error using ==> mex at 208
Unable to complete successfully.

不知何故，我没有提供正确的标记来正确链接.如果我删除了gcc44命令中链接的命令，就会遇到同样的错误(还有更多错误)，因此我很确定自己不会让编译器看到"这些库.

Somehow, I'm not giving the correct flags to link appropriately. As I get the same set of errors (plus a few more) if I remove the commands to link in the gcc44 command, I'm pretty sure that I'm not getting the compiler to "see" the libraries.

我的问题是:

  • 如果我对错误的分析是正确的，我需要将哪些标志传递给mex编译命令以成功链接?
  • 或者，要在Matlab环境之外进行编译和链接的gcc标志是什么?
  • 如果我的分析是错误的，从哪里去?

我认为我已经排除了不受支持的编译器警告，因为我已经能够使用gcc 4.4使用OpenMP程序编译简单的mex，但是除了数学库之外，这些都不需要链接.另外，如果我使用gcc版本4.1.2或4.3.4进行编译，无论是否带有"-fopenmp"标志，我都会遇到相同的错误.

I think I've ruled out the unsupported compiler warning since I've been able to compile simple mex with OpenMP programs using gcc 4.4, but these did not have to link against anything except the math library. Also, if I compile with version gcc version 4.1.2 or 4.3.4 with or without the "-fopenmp" flags I get the same error.

最后，我确实需要版本4.4，因为某些OpenMP支持在以前的版本中没有出现.

In the end I do need version 4.4 because of certain OpenMP support that did not appear in prior versions.

预先感谢您的帮助.

-安德鲁

(@KWATFORD)

Edits: (@KWATFORD)

所以我尝试使用引号外的语句执行命令，并得到错误:

So I tried the command with the statements outside the the quotes, and got the error:

-> gcc44 -c  -I/home/matteson/sundials/include/ -I/misc/linux/64/opt/pkg/matlab/R2010b/extern/include -I/misc/linux/64/opt/pkg/matlab/R2010b/simulink/include -DMATLAB_MEX_FILE -ansi -D_GNU_SOURCE  -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fopenmp  -DMX_COMPAT_32 -O -DNDEBUG  "mex_cvode.c"

-> gcc44 -O -pthread -shared -Wl,--version-script,/misc/linux/64/opt/pkg/matlab/R2010b/extern/lib/glnxa64/mexFunction.map -Wl,--no-undefined -fopenmp -o  "mex_cvode.mexa64"  mex_cvode.o  -L/home/matteson/sundials/lib -lsundials_cvode -lsundials_nvecserial -Wl,-rpath-link,/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -L/misc/linux/64/opt/pkg/matlab/R2010b/bin/glnxa64 -lmx -lmex -lmat -lm -lstdc++

/usr/bin/ld: /home/matteson/sundials/lib/libsundials_cvode.a(cvode.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC
/home/matteson/sundials/lib/libsundials_cvode.a: could not read symbols: Bad value
collect2: ld returned 1 exit status

    mex: link of ' "mex_cvode.mexa64"' failed.

??? Error using ==> mex at 208
Unable to complete successfully.

对于使用"-fPIC"重新编译的建议我有些困惑，因为当我查看gcc44命令时，我将-fPIC作为选项.

I'm a bit confused about the suggestion to recompile with "-fPIC" because when I look at the gcc44 command I see the -fPIC as an option.

他们是说要用-fPIC重新编译该库吗?

Are they saying to recompile the library with -fPIC?

我没有该库的源代码，如果建议重新编译该库，是否有解决方法?

I don't have the source for the library, if the suggestion is to recompile the library is there a workaround?

针对本地对象的重定位"是什么意思?

What does "relocation against local object" mean?

我继续表示感谢.

推荐答案

尽量不要将-l，-L或-I参数放在这些环境变量中. mex函数将直接处理这些类型的参数.所以也许像这样:

Try not putting the -l, -L, or -I arguments in those environment variables. The mex function will handle those types of arguments directly. So perhaps something like:

mex -v CC="gcc44" CFLAGS="\$CFLAGS -fopenmp" LDFLAGS="\$LDFLAGS -fopenmp" -I/home/matteson/sundials/include/ -L/home/matteson/sundials/lib -lsundials_cvode -lsundials_nvecserial mex_cvode.c

这篇关于在Matlab的MEX编译过程中如何链接的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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