When I generate LLVM IR Code from C++, I can use the console command clang++ -emit-llvm –S test.cpp to get a test.ll file which is the LLVM IR I want.
To get an executable these are the steps to follow:
llvm-as test.ll -> gives me the test.bc file.
llc test.bc --o test.s -> gives me the test.s file.
clang++ test.s -o test.native -> gives me a native file that i can execute.
For C++ this works just fine.
In theory, should the same steps apply when I write Rust or Python Code?
I take my Rust code and get the LLVM IR by typing rustc test.rs --emit llvm-ir. This gives me the test.ll file again.
For Python, I use "Numba" and get the LLVM IR by typing numba --dump-llvm test.py> test.llwhich also gives me the test.ll file.
The steps to generate an executable from those .ll files should be the same.
They work up until the last step that creates the native executable:
Python Error
/tmp/test-9aa440.o: In function 'main':
test.bc:(.text+0x67): undefined reference to 'numba_gil_ensure'
test.bc:(.text+0x79): undefined reference to 'numba_unpickle'
test.bc:(.text+0x84): undefined reference to 'PyObject_Str'
test.bc:(.text+0x8f): undefined reference to 'PyString_AsString'
test.bc:(.text+0xa1): undefined reference to 'PySys_WriteStdout'
test.bc:(.text+0xa9): undefined reference to 'Py_DecRef'
test.bc:(.text+0xb1): undefined reference to 'Py_DecRef'
test.bc:(.text+0xbd): undefined reference to 'PySys_WriteStdout'
test.bc:(.text+0xc5): undefined reference to 'numba_gil_release'
test.bc:(.text+0xff): undefined reference to 'numba_gil_ensure'
test.bc:(.text+0x10b): undefined reference to 'PySys_WriteStdout'
test.bc:(.text+0x113): undefined reference to 'numba_gil_release'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Rust Error
/tmp/main-5e59bd.o: In function ‘main::sum::h514304ffa40dd7c3’:
main.bc:(.text+0xf): undefined reference to ‘core::panicking::panic::h2596388ccef1871c’
/tmp/main-5e59bd.o: In function ‘main’: main.bc:(.text+0x53): undefined reference to ‘std::rt::lang_start::h65647f6e36cffdae’
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What I get from this is that clang doesn't understand the Rust/Python specific parts of the LLVM IR file (e.g. "PyObject" in Python or "panic" from Rust) that were used to generate the .bc, .s and in theory the .native files.
But why are those even in the IR in the first place? Shouldn't the LLVM IR be uniform and those parts be transformed so the LLVM toolchain can work with them?
As far as I know LLVMs modularity should allow those steps by using LLVM IR. Is there maybe another way to do this i don't know about?
Can I generate the IRs from those languages in some other way that gives "pure" LLVM IR that clang understands, or could I still generate executables from those files, but in some other way without clang?
I can speak of Rust code:
You need to link Rust's std library something like this:
$(LLI) -load /Users/Stanislaw/.rustup/toolchains/stable-x86_64-apple-darwin/lib/libstd-f5a209a9.dylib ./target/debug/jitrust.bc
See the full example of Makefile I use here.
P.S. I would assume that the same goes about Python. You have to also supply libraries which contain this "unreferenced" stuff.
Related
Describe what happened:
For context, i am currently trying to embed python into golang. I came across this module go-python3 and decided to use it. I was originally using the python3.7 variant of the module then decided to upgrade my python version from 3.7 to 3.8.
Read: https://github.com/go-python/cpy3/issues/29#issuecomment-1321199010
I replaced python3.pc in pkgconfig with python-3.8.pc and got the following error when trying to run:
protoc -Isrc/proto --go_opt=module=grpc-golang --go_out=. --go-grpc_opt=module=grpc-golang --go-grpc_out=. src/proto/*.proto
go build -o dest/server ./src/server && PYTHONPATH=.
# grpc-golang/src/server
/usr/local/go/pkg/tool/linux_amd64/link: running gcc failed: exit status 1
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0x78): undefined reference to `PyBool_Type'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0x80): undefined reference to `PyByteArray_Type'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0x88): undefined reference to `PyBytes_Type'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0x90): undefined reference to `PyComplex_Type'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0x98): undefined reference to `PyDict_Type'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xa0): undefined reference to `PyExc_ArithmeticError'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xa8): undefined reference to `PyExc_AssertionError'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xb0): undefined reference to `PyExc_AttributeError'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xb8): undefined reference to `PyExc_BaseException'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xc0): undefined reference to `PyExc_BlockingIOError'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xc8): undefined reference to `PyExc_BrokenPipeError'
/usr/bin/ld: /tmp/go-link-2733155445/go.o:(.data+0xd0): undefined reference to `PyExc_BufferError'
:
This are some of the details:
>> python3 --version
3.8.10
>> pkg-config --cflags --libs python3
-I/usr/include/python3.8 -I/usr/include/x86_64-linux-gnu/python3.8
>> echo $PKG_CONFIG_PATH
/usr/lib/x86_64-linux-gnu/pkgconfig/
>> pkg-config --list-all
python-3.8 Python - Build a C extension for Python
zlib zlib - zlib compression library
protobuf-lite Protocol Buffers - Google's Data Interchange Format
bash-completion bash-completion - programmable completion for the bash shell
xkeyboard-config XKeyboardConfig - X Keyboard configuration data
protobuf Protocol Buffers - Google's Data Interchange Format
systemd systemd - systemd System and Service Manager
libdmmp libdmmp - Device mapper multipath management library
python3 Python - Build a C extension for Python
libxcrypt libxcrypt - Extended crypt library for DES, MD5, Blowfish and others
udev udev - udev
shared-mime-info shared-mime-info - Freedesktop common MIME database
python-3.8-embed Python - Embed Python into an application
expat expat - expat XML parser
python3-embed Python - Embed Python into an application
libcrypt libxcrypt - Extended crypt library for DES, MD5, Blowfish and others
Describe what you expected:
Should be able to work fine, like its 3.7 variant.
I ran into a similar problem just recently. After searching through a few forums on embedding python, I ran into this one: "Embedding Python in C, linking fails with undefined reference to `Py_Initialize'" 1. I wasn't entirely sure how to do this at first in golang, but I had been doing other online searches on embedded python in golang. Going back through these, I landed at an article call, "Python and Go : Part IV - Using Python in Memory" 2, where it describes in the "Building" section how to specify specific flags to be use in the C building process. Basically, it shows that you can define flags in one of files as such:
/*
#cgo pkg-config: python3
#cgo LDFLAGS: -L/usr/local/lib/python3.8/config-3.8-x86_64-linux-gnu -L/usr/local/lib -lpython3.8 -lcrypt -ldl -lm -lm
#include "Python.h"
*/
import "C"
Although, according to Python's documentation on compiling a python interpreter embedded in another application, you should get the LDFLAGS via,
python3.7-config --ldflags
for python versions <= 3.7 (I don't know how far back if goes. Also, replace the "python3.7-config" accordingly), or,
python3.10-config --ldflags --embed
for python versions > 3.7 (And once again, replace the "python3.10-config" part with the desired python version)
I then thought to myself, "A version of this header is probably located somewhere in the go-python project and it just needs to be changed", so after looking around, I found this header in the high_level_layer.go file in the project and modified it to match what's shown above.
What's exactly going on here is that golang has native functionality with C, so libraries written in C can work in golang, and the opposite is also true (with enough finagling). There's plenty of articles on this functionality. Here's one from go's official website, 3. And since the base python interpreter is written in C, its header and object files can be referenced at compile time by the golang compiler if the linker flags and other flags are set correctly, so that's exactly what's being specified above.
Also, on a different note, I've tried compiling with a few different go compilers. I've had success with the compiler for versions 1.15.5 and 1.18.1, but haven't with 1.19.5. I don't know what's exactly happening, but I'm not going to try and figure it out right now since all I need currently are features in compiler versions >= 1.18. Lastly, I actually had basically the same problems with python3.7, and these changes fixed these problems too...
Try to embed python3.6 in C++ on Win10 64bit system.
Python is installed by python-3.6.1-amd64.exe.
The CMakeList.txt is showing below
cmake_minimum_required(VERSION 3.8)
project(EmbedPython)
set(CMAKE_CXX_STANDARD 11)
set(SOURCE_FILES main.cpp)
find_package(PythonLibs REQUIRED)
include_directories(${PYTHON_INCLUDE_DIRS})
add_executable(EmbedPython ${SOURCE_FILES} ${PYTHON_INCLUDE_DIRS})
target_link_libraries(EmbedPython ${PYTHON_LIBRARIES})
And CMake found the Python package.
PYTHON_INCLUDE_DIR C:/Program Files (x86)/Python36/include
PYTHON_LIBRARY C:/Program Files (x86)/Python36/libs/python36.lib
Find a comment on github it's talking about the API problem.
# used to embed python script
find_package(PythonLibs 2.7 REQUIRED) # this has to be 2.7 because the 3.0 API requires argv to be wchar_t** rather than the default char**
include_directories(${PYTHON_INCLUDE_DIRS})
target_link_libraries( assignment ${PYTHON_LIBRARIES})
The errors below is what I'm facing.
[ 50%] Building CXX object CMakeFiles/EmbedPython.dir/main.cpp.obj
[100%] Linking CXX executable EmbedPython.exe
CMakeFiles\EmbedPython.dir/objects.a(main.cpp.obj): In function `main':
D:/Projects/EmbedPython/main.cpp:16: undefined reference to `_imp__Py_Initialize'
D:/Projects/EmbedPython/main.cpp:17: undefined reference to `_imp__PyUnicode_DecodeFSDefault'
D:/Projects/EmbedPython/main.cpp:20: undefined reference to `_imp__PyImport_Import'
D:/Projects/EmbedPython/main.cpp:24: undefined reference to `_imp__PyObject_GetAttrString'
D:/Projects/EmbedPython/main.cpp:27: undefined reference to `_imp__PyCallable_Check'
D:/Projects/EmbedPython/main.cpp:28: undefined reference to `_imp__PyTuple_New'
D:/Projects/EmbedPython/main.cpp:30: undefined reference to `_imp__PyLong_FromLong'
D:/Projects/EmbedPython/main.cpp:38: undefined reference to `_imp__PyTuple_SetItem'
D:/Projects/EmbedPython/main.cpp:40: undefined reference to `_imp__PyObject_CallObject'
D:/Projects/EmbedPython/main.cpp:43: undefined reference to `_imp__PyLong_AsLong'
D:/Projects/EmbedPython/main.cpp:49: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:55: undefined reference to `_imp__PyErr_Occurred'
D:/Projects/EmbedPython/main.cpp:56: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:63: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:67: undefined reference to `_imp__Py_FinalizeEx'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[3]: *** [EmbedPython.exe] Error 1
mingw32-make.exe[2]: *** [CMakeFiles/EmbedPython.dir/all] Error 2
mingw32-make.exe[1]: *** [CMakeFiles/EmbedPython.dir/rule] Error 2
mingw32-make.exe: *** [EmbedPython] Error 2
CMakeFiles\EmbedPython.dir\build.make:96: recipe for target 'EmbedPython.exe' failed
CMakeFiles\Makefile2:66: recipe for target 'CMakeFiles/EmbedPython.dir/all' failed
CMakeFiles\Makefile2:78: recipe for target 'CMakeFiles/EmbedPython.dir/rule' failed
Makefile:117: recipe for target 'EmbedPython' failed
Not sure what to do to make the project run.Any help would be appreciated.
EDIT:
the result from make VERBOSE=1
D:\Projects\EmbedPython\cmake-build-debug>make VERBOSE=1
"C:\Program Files\JetBrains\CLion 172.2273.4\bin\cmake\bin\cmake.exe" -HD:\Projects\EmbedPython -BD:\Projects\EmbedPython\cmake-build-debug --check-build-system CMakeFiles\Makefile.cmake 0
"C:\Program Files\JetBrains\CLion 172.2273.4\bin\cmake\bin\cmake.exe" -E cmake_progress_start D:\Projects\EmbedPython\cmake-build-debug\CMakeFiles D:\Projects\EmbedPython\cmake-build-debug\CMakeFiles\progress.marks
make -f CMakeFiles\Makefile2 all
make[1]: Entering directory 'D:/Projects/EmbedPython/cmake-build-debug'
make -f CMakeFiles\EmbedPython.dir\build.make CMakeFiles/EmbedPython.dir/depend
make[2]: Entering directory 'D:/Projects/EmbedPython/cmake-build-debug'
"C:\Program Files\JetBrains\CLion 172.2273.4\bin\cmake\bin\cmake.exe" -E cmake_depends "MinGW Makefiles" D:\Projects\EmbedPython D:\Projects\EmbedPython D:\Projects\EmbedPython\cmake-build-debug D:\Projects\EmbedPython\cmake-build-debug D:\Projects\EmbedPython\cmake-build-debug\CMakeFiles\EmbedPython.dir\DependInfo.cmake --color=
make[2]: Leaving directory 'D:/Projects/EmbedPython/cmake-build-debug'
make -f CMakeFiles\EmbedPython.dir\build.make CMakeFiles/EmbedPython.dir/build
make[2]: Entering directory 'D:/Projects/EmbedPython/cmake-build-debug'
[ 50%] Linking CXX executable EmbedPython.exe
"C:\Program Files\JetBrains\CLion 172.2273.4\bin\cmake\bin\cmake.exe" -E cmake_link_script CMakeFiles\EmbedPython.dir\link.txt --verbose=1
"C:\Program Files\JetBrains\CLion 172.2273.4\bin\cmake\bin\cmake.exe" -E remove -f CMakeFiles\EmbedPython.dir/objects.a
C:\PROGRA~2\MINGW-~1\I686-6~1.0-P\mingw32\bin\ar.exe cr CMakeFiles\EmbedPython.dir/objects.a #CMakeFiles\EmbedPython.dir\objects1.rsp
C:\PROGRA~2\MINGW-~1\I686-6~1.0-P\mingw32\bin\G__~1.EXE -g -Wl,--whole-archive CMakeFiles\EmbedPython.dir/objects.a -Wl,--no-whole-archive -o EmbedPython.exe -Wl,--out-implib,libEmbedPython.dll.a -Wl,--major-image-version,0,--minor-image-version,0 #CMakeFiles\EmbedPython.dir\linklibs.rsp
CMakeFiles\EmbedPython.dir/objects.a(main.cpp.obj): In function `main':
D:/Projects/EmbedPython/main.cpp:16: undefined reference to `_imp__Py_Initialize'
D:/Projects/EmbedPython/main.cpp:17: undefined reference to `_imp__PyUnicode_DecodeFSDefault'
D:/Projects/EmbedPython/main.cpp:20: undefined reference to `_imp__PyImport_Import'
D:/Projects/EmbedPython/main.cpp:24: undefined reference to `_imp__PyObject_GetAttrString'
D:/Projects/EmbedPython/main.cpp:27: undefined reference to `_imp__PyCallable_Check'
D:/Projects/EmbedPython/main.cpp:28: undefined reference to `_imp__PyTuple_New'
D:/Projects/EmbedPython/main.cpp:30: undefined reference to `_imp__PyLong_FromLong'
D:/Projects/EmbedPython/main.cpp:38: undefined reference to `_imp__PyTuple_SetItem'
D:/Projects/EmbedPython/main.cpp:40: undefined reference to `_imp__PyObject_CallObject'
D:/Projects/EmbedPython/main.cpp:43: undefined reference to `_imp__PyLong_AsLong'
D:/Projects/EmbedPython/main.cpp:49: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:55: undefined reference to `_imp__PyErr_Occurred'
D:/Projects/EmbedPython/main.cpp:56: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:63: undefined reference to `_imp__PyErr_Print'
D:/Projects/EmbedPython/main.cpp:67: undefined reference to `_imp__Py_FinalizeEx'
collect2.exe: error: ld returned 1 exit status
CMakeFiles\EmbedPython.dir\build.make:97: recipe for target 'EmbedPython.exe' failed
make[2]: *** [EmbedPython.exe] Error 1
make[2]: Leaving directory 'D:/Projects/EmbedPython/cmake-build-debug'
CMakeFiles\Makefile2:66: recipe for target 'CMakeFiles/EmbedPython.dir/all' failed
make[1]: *** [CMakeFiles/EmbedPython.dir/all] Error 2
make[1]: Leaving directory 'D:/Projects/EmbedPython/cmake-build-debug'
Makefile:82: recipe for target 'all' failed
make: *** [all] Error 2
I had the exactly same problem, just with Python 3.7 while trying to build the example from the Python manual.
My system is a 64-bit Windows, the installed Python is a 64-bit 3.7 (from Anaconda3), and the compiler is a 32-bit MinGW 5.3.0 (from Qt 5.11).
The simplest solution that worked for me is the following:
Download Windows x86 embeddable zip file from this page.
Put the content of that archive to a folder inside the project you're building.
Do not install anything from that archive and do not put it on the system PATH.
Add the above folder to the gcc library search path, using: -L"path/to/folder/"
Add the python library to the linker, using -l"python37" ( replace 37 with whatever version you download)
As noted here (this was a hard one to find!), add a definition, using -DPy_BUILD_CORE_BUILTIN=1 (It is also possible to write #define DPy_BUILD_CORE_BUILTIN 1 just before #include-ing the Python header, though I would not recommend it)
Provide the path to the Python headers, using -I"path/to/include". I used the one from Anaconda, e.g. -I"c:/Users/user/Anaconda3/include/". Any installed header will do, just make sure its from the same version (headers from an older version might also be used, but this may cause a rupture in the space-time continuum)
Make sure that #include <Python.h> is before any other include, as stated in the manual.
As a side note, the MinGW linker (ld) is perfectly content, for many years now, if you just give it the "dll" file. No "lib", nor "a", is needed if you don't have one and only perform dynamic linking. This is why I just told the linker to use python37.
It it actually smart enough to look for files like python37.lib, python37.dll & libpython37.a.
Also note that the "embedable zip" is just the bare minimum needed for, well, embedding Python.
And as a last comment, contrary to what is stated here, there is no problem whatsoever linking from GCC with a library compiled using MSVS (and vice versa), as long as the library uses the plain C interface, since that interface is pretty much the only thing that is compatible across different compilers for any given platform.
This is pretty much the exact reason why Python is using the C interface (and nothing else, not even C++) for extending & embedding - to allow code written in any language, using any tool set, to interface with Python.
I had the same problem.
probably the problem is because of using 32 bit MinGW and 64 bit Python. you should install 32 bit version of python
Hope it will be useful to you :-)
I am trying to compile a Python library (CEGUI can build Python modules, its editor relies on that) that needs to link against boost-python. So I built boost, with --with-python and it built just fine.
However, as soon as the .pyd is linked, I get undefined references:
Linking CXX shared module ..\..\..\..\..\bin\PyCEGUI.pyd
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x97): undefined reference to `_imp___ZN5boost6python7objects10class_baseC2EPKcjPKNS0_9type_infoES4_'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x9c): undefined reference to `_imp___ZN5boost6python9converter8registry6insertEPFPvP7_objectEPFvS5_PNS1_30rvalue_from_python_stage1_dataEENS0_9type_infoEPFPK11_typeobjectvE
'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0xcc): undefined reference to `_imp___ZN5boost6python7objects23register_dynamic_id_auxENS0_9type_infoEPFSt4pairIPvS2_ES4_E'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0xf4): undefined reference to `_imp___ZN5boost6python7objects8add_castENS0_9type_infoES2_PFPvS3_Eb'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x1cd): undefined reference to `_imp___ZN5boost6python7objects17copy_class_objectERKNS0_9type_infoES4_'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x20d): undefined reference to `_imp___ZN5boost6python9converter8registry6insertEPFP7_objectPKvENS0_9type_infoEPFPK11_typeobjectvE'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x245): undefined reference to `_imp___ZN5boost6python7objects10class_base17set_instance_sizeEj'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x281): undefined reference to `_imp___ZN5boost6python7objects15function_objectERKNS1_11py_functionERKSt4pairIPKNS0_6detail7keywordES9_E'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x2f2): undefined reference to `_imp___ZN5boost6python7objects16add_to_namespaceERKNS0_3api6objectEPKcS5_S7_'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x348): undefined reference to `_imp___ZN5boost6python6detail13current_scopeE'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x4d1): undefined reference to `_imp___ZN5boost6python9converter8registry9push_backEPFPvP7_objectEPFvS5_PNS1_30rvalue_from_python_stage1_dataEENS0_9type_infoEPFPK11_typeobjectvE'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x636): undefined reference to `_imp___ZN5boost6python7objects16add_to_namespaceERKNS0_3api6objectEPKcS5_'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x1246): undefined reference to `_imp___ZN5boost6python6detail13current_scopeE'
CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):AbsoluteDim.pypp.cpp:(.text+0x1267): undefined reference to `_imp___ZN5boost6python6detail13current_scopeE'
c:/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe: CMakeFiles\PyCEGUI.dir/objects.a(AbsoluteDim.pypp.cpp.obj):
bad reloc address 0x2 in section `.text$_ZN5boost6detail15sp_counted_baseD1Ev[__ZN5boost6detail15sp_counted_baseD1Ev]'
collect2.exe: error: ld returned 1 exit status
cegui\src\ScriptModules\Python\bindings\CMakeFiles\PyCEGUI.dir\build.make:6698: recipe for target 'bin/PyCEGUI.pyd' failed
mingw32-make[2]: *** [bin/PyCEGUI.pyd] Error 1
CMakeFiles\Makefile2:726: recipe for target 'cegui/src/ScriptModules/Python/bindings/CMakeFiles/PyCEGUI.dir/all' failed
mingw32-make[1]: *** [cegui/src/ScriptModules/Python/bindings/CMakeFiles/PyCEGUI.dir/all] Error 2
Makefile:135: recipe for target 'all' failed
mingw32-make: *** [all] Error 2
My first assumption was that it does not link against boost-python, but the link.txt inside the CMake folders shows this:
"C:\Coding\CMake 2.8\bin\cmake.exe" -E remove -f
CMakeFiles\PyCEGUI.dir/objects.a C:\MinGW\bin\ar.exe cr
CMakeFiles\PyCEGUI.dir/objects.a #CMakeFiles\PyCEGUI.dir\objects1.rsp
C:\MinGW\bin\g++.exe -shared -o ..........\bin\PyCEGUI.pyd
-Wl,--major-image-version,0,--minor-image-version,0 -Wl,--whole-archive CMakeFiles\PyCEGUI.dir/objects.a -Wl,--no-whole-archive ..........\lib\libCEGUIBase-0.dll.a C:\Coding\boost_1_53_0\lib\libboost_python-mgw48-mt-1_53.a
C:\Python27\libs\python27.lib
C:\Coding\CEGUI\cegui\dependencies\lib\dynamic\libfreetype.dll.a
C:\Coding\CEGUI\cegui\dependencies\lib\dynamic\libpcre.dll.a -lwinmm
-lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32
So boost-python is linked against.
I am unsure what could be the problem here. Boost? CEGUI? MinGW?...
Turns out, the problem was that I was using the 64bit version of Python. I downloaded it months ago and just forgot about that little fact.
Now, MinGW can only compile and use 32 bit libraries, not mix in 64 bit. This is what led to boost-python not compiling correctly (it's a wonder it did compile at all) and thus having undefined references when linked against.
Downloading the 32bit version of Python and recompiling boost solved the problems.
So I have a few Python C extensions I have previously built for and used in 32 bit Python running in Win7. I have now however switched to 64 bit Python, and I am having issues building the C extension with MinGW-w64.
I made the changes to distutils as per this post, but I am getting some weird errors suggesting something is wrong:
$ python setup.py build
running build
running build_ext
building 'MyLib' extension
c:\MinGW64\bin\x86_64-w64-mingw32-gcc.exe -mdll -O -Wall -Ic:\Python27\lib\site-packages\numpy\core\include -Ic:\Python27\include -Ic:\Python27\PC -c MyLib.c -o build\temp.win-amd64-2.7\Release\mylib.o
MyLib.c: In function 'initMyLib':
MyLib.c:631:5: warning: implicit declaration of function 'Py_InitModule4_64' [-Wimplicit-function-declaration]
writing build\temp.win-amd64-2.7\Release\MyLib.def
c:\MinGW64\bin\x86_64-w64-mingw32-gcc.exe -shared -s build\temp.win-amd64-2.7\Release\mylib.o build\temp.win-amd64-2.7\Release\MyLib.def -Lc:\Python27\libs -Lc:\Python27\PCbuild\amd64 -lpython27 -o build\lib.win-amd64-2.7\MyLib.pyd
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x13d): undefined reference to `__imp_PyExc_ValueError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1275): undefined reference to `__imp_PyExc_ValueError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1eef): undefined reference to `__imp_PyExc_ImportError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1f38): undefined reference to `__imp_PyExc_AttributeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1f4d): undefined reference to `__imp_PyCObject_Type'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1f61): undefined reference to `__imp_PyExc_RuntimeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1fc7): undefined reference to `__imp_PyExc_RuntimeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x1ffe): undefined reference to `__imp_PyExc_RuntimeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x2042): undefined reference to `__imp_PyExc_RuntimeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x206c): undefined reference to `__imp_PyExc_RuntimeError'
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x208a): more undefined references to `__imp_PyExc_RuntimeError' follow
build\temp.win-amd64-2.7\Release\mylib.o:MyLib.c:(.text+0x20a7): undefined reference to `__imp_PyExc_ImportError'
collect2.exe: error: ld returned 1 exit status
error: command 'x86_64-w64-mingw32-gcc' failed with exit status 1
I have googled around quite a bit to find information, but it's not easy to find a definite answer. Could someone shed some light on this? What further changes should I do to be able to successfully build C extensions for 64 bit Python in Win7?
EDIT:
After some helpful pointers in cgohlke's comments below I managed to generate libpython27.a. However after following the advice on this post (2nd to last) I still had a the __imp_Py_InitModule4_64 error. After some serious Google-fu I managed to trip over this post telling me to rename the Py_InitModule4 line to Py_InitModule4_64. After that everything worked swimmingly.
This worked for me with Python 3.3 :
create static python lib from dll
python dll is usually in C:/Windows/System32; in msys shell:
gendef.exe python33.dll
dlltool.exe --dllname python33.dll --def python33.def --output-lib libpython33.a
mv libpython33.a C:/Python33/libs
use swig to generate wrappers
e.g., swig -c++ -python myExtension.i
wrapper MUST be compiled with MS_WIN64, or your computer will crash when you import the class in Python
g++ -c myExtension.cpp -I/other/includes
g++ -DMS_WIN64 -c myExtension_wrap.cxx -IC:/Python33/include
shared library
g++ -shared -o _myExtension.pyd myExtension.o myExtension_wrap.o -lPython33 -lOtherSharedLibs -LC:/Python33/libs -LC:/path/to/other/shared/libs
make sure all shared libs (gdal, OtherSharedLibs) are in your PATH
(windows does not use LD_LIBRARY_PATH or PYTHONPATH)
in Python, just: import myExtension
voila!
I realize this is an old question, but it is still the top search result. Today, in 2019, I was able to do this:
https://github.com/PetterS/quickjs/commit/67bc2428b8c0716538b4583f4f2b0a2a5a49106c
In short:
Make sure a 64-bit version of mingw-w64 is in the PATH.
Monkey-patch distutils:
import distutils.cygwinccompiler
distutils.cygwinccompiler.get_msvcr = lambda: []
Some differences in the shell w.r.t. escaping.
extra_link_args = ["-Wl,-Bstatic", "-lpthread"] in order to link statically and not have extra runtime deps.
pipenv run python setup.py build -c mingw32 now works.
Here is a example code for VC++ Build Tools
https://github.com/starnight/python-c-extension/tree/master/00-HelloWorld
You could try:
python setup.py -c mingw32
However this is not work for me.
My Solution is:
install Anaconda 64bit python 3.6
install mingw64
add mingw64/bin to PATH
compile dll from c file by
gcc -c libmypy.c -IC:\Users\{user_name}\Anaconda3\pkgs\python-3.6.4-h6538335_1\include
gcc -shared -o libmypy.dll libmypy.o -LC:\Users\{user_name}\Anaconda3\pkgs\python-3.6.4-h6538335_1\libs -lPython36
load dll file in .py script
from ctypes import *
m = cdll.LoadLibrary(r"C:\{path_to_dll}\libmypy.dll")
print(m.hello())
I created a monkey-patch for setuptools to let you to build_ext with mingw64 on Windows easily. See https://github.com/imba-tjd/mingw64ccompiler
I used this thread to wade through learning how to make a C extension, and since most of what I learned is in it, I thought I'd put the final discovery here too, so that someone else can find it if they are looking.
I wasn't trying to compile something big, just the example in Hetland's Beginning Python. Here is what I did (the example C pgm is called palindrome.c). I'm using Anaconda with python 3.7 in it, and the TDM-GCC version of MinGW64. I put all of the tools used into my Path, and all of the paths needed in PYTHONPATH, and the ..\Anaconda3 directory into PYTHON_HOME. I still ended up using explicit paths on some things.
I created the libpython37.a library with gendef.exe and dlltool.exe as Mark said above, and put it in ..\Anaconda3\libs.
I followed the prescription in Hetland:
gcc -c palindrome.c
gcc -I$PYTHON_HOME -I$PYTHON_HOME/Include -c palindrome_wrap.c
The second failed, the compiler couldn't find Python.h, the following worked:
gcc -I[somedirectories]\Anaconda3\Include -c palindrome_wrap.c
I then did, as many have said, including Hetland 3rd ed.,
gcc -shared palindrome.o palindrome_wrap.o [somedirectories]/Anaconda3/libs/libpython37.a -o _palindrome.dll
This did not work. Even with the Load Library cswu used (which I found elsewhere, too).
So I gendef'd _palindrome.dll and couldn't find the function in it, "is_palindrome" in the exports. I went through some of the SWIG documentation, and declared the function both in the %{ %} section and below it, both extern, that finally got the function extern'd in palindrome_wrap.c as it should have been. But no export, so I went back into palindrome.c and redeclared the function as:
declspec(dllexport) extern int __stdcall is_palindrome(char* text)
and redeclared it in palindrome.i in both places as above with this signature.
Partial success! It got listed in the Export section when I gendef'd _palindrome.dll and I could do cswu's call using Load Library. But still not do what Hetland says and do
import _palindrome
in Python.
Going back to all the sources again, I could not figure this out. I finally started reading the SWIG documentation from the beginning leaving no stone unturned -- Searching through the manual doesn't produce the place found.
At the end of Introduction Sec. 2.7 Incorporating Into a Build System, under the sample Make process, it says:
"The above example will generate native build files such as makefiles, nmake files and Visual Studio projects which will invoke SWIG and compile the generated C++ files into _example.so (UNIX) or _example.pyd (Windows). For other target languages on Windows a dll, instead of a .pyd file, is usually generated."
And that's the answer to the last problem:
The compile step for the dll should read:
gcc -shared palindrome.o palindrome_wrap.o [somedirectories]/Anaconda3/libs/libpython37.a -o _palindrome.pyd
(I didn't go back and change out my declspec declarations so I don't know whether they were necessary, so they were still there too).
I got a file, _palindrome.pyd
Which if in the PYTHONPATH (mine was local) works, and one can then do
import _palindrome
from _palindrome import is_palindrome
and use the exported, properly wrapped and packaged C function, compiled with TDM-GCC, in python as promised. gcc, which is MinGW64 in a different installation, knows how to do the .pyd file. I diffed the dll and pyd since they were the same byte length. They are not the same at hundreds of points.
Hope this helps someone else.
I'm attempting to build CPython 3.2 using llvm's clang. It builds OK with gcc. I'm on Linux Mint 12.
The compile seems to go fine until the end, where it attempts to produce the ./python binary. The error I get is:
clang -pthread -Xlinker -export-dynamic -o python Modules/python.o libpython3.2m.a -lpthread -ldl -lutil -lm
/usr/bin/ld: error: libpython3.2m.a: malformed archive header name at 8
./Modules/python.c:25: error: undefined reference to 'PyMem_Malloc'
./Modules/python.c:27: error: undefined reference to 'PyMem_Malloc'
./Modules/python.c:51: error: undefined reference to '_Py_char2wchar'
./Modules/python.c:59: error: undefined reference to 'Py_Main'
./Modules/python.c:61: error: undefined reference to 'PyMem_Free'
./Modules/python.c:63: error: undefined reference to 'PyMem_Free'
./Modules/python.c:64: error: undefined reference to 'PyMem_Free'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I've tried with the llvm 2.9 that's in my trusty Linux Mint 12 .deb repo, and with an SVN trunk of llvm from earlier today, but both give the same errors.
It occurs to me that perhaps things would go better if I could persuade clang to use llvm-link instead of /usr/bin/ld for linking, but I see nothing in the documentation about how to do that. Just setting $LD to llvm-link doesn't appear to help.
Those undefined references are likely red herrings: If I nm -o libpython3.2m.a (or llvm-nm -o libpython3.2m.a - both work), I can see that at least one of these symbols really is defined (according to nm of course - other tools could perhaps, and likely do, have other ideas).
Ultimately I want to generate llvm bitcode rather than an ELF binary, but it'd be a satisfying mini-milestone to get a working python ELF binary with llvm first.
I'm currently using the following for compilation:
export PATH=/usr/local/llvm/bin:$PATH
prefix=/usr/local/p3ib-3.2
export CC='clang'
export AR='llvm-ar'
export LD='llvm-link -emit-llvm-bc'
export RANLIB='llvm-ranlib'
./configure --prefix="$prefix" && make -j 3
Thanks!