Ipo with shared library

[ChrisC2]

I've been trying on an off for some time now to get Ipo compilation and linking to work with a shared library I am building.   Thought I would try again with 2024.1, and still no luck.    Project is build with CMake (3.28) in VS2022.   

Long story short, I get the message 'llvm-nm returned an error : /usr/bin/nm: unrecognized option '--no-weak'

I assume Cmake is trying to turn off weak linking, which is causing a failure.   I've both tried manually specifying the ipo commands, and also using setting INTERPROCEDURAL_OPTIMIZTION to True to let Cmake handle the flags.  Both get the same message above.   

[Barbara_P_Intel]

Please post a small reproducer. There's not enough information here to offer any advice.

[ChrisC2]

I've attached a simple CMake project that replicates the error for me.  I'm using VS2022 to run this, but should be able to run it in a standalone CLI as well.   If the library type is changed from SHARED to STATIC, it compiles with no issues.  

[Barbara_P_Intel]

@ChrisC2, have you had any success in resolving this?

Are you using ifort or ifx? For me your .sln is using ifort.

I'm a little confused about what OS you are using. You mention VS 2022, but the path in the error message is a Linux path.

Does the .sln you uploaded compile successfully for you or is this the failing version?

I'm using Windows 11, VS2022 17.8.1, cmake version 3.27.2-msvc1, ifort 2021.12.0.

[ChrisC2]

I have not resolved it.  

The compiler is ifx.   (Line 3 of the top level CMakeLists.txt sets compiler to ifx)

I've tried to build in both Linux and Windows and both show a similar error.   I must have grabbed the error message from linux.  (Though Windows I have OneAPI 2024.1, Linux is 2023.2)

This being a CMake project, there is no sln file.  But you can open it in Visual Studio via File > Open > Folder.  And yes, the uploaded project shows the behavior for me.   

I've copied in the build output file for a Windows build in Visual Studio.   Perhaps this provides some more details.   

>------ Build All started: Project: dynamic_link_error, Configuration: x64-release ------
[1/6] Building Fortran preprocessed src\CMakeFiles\test_module.dir\test_module.f90-pp.f90
[2/6] Generating Fortran dyndep file src\CMakeFiles\test_module.dir\Fortran.dd
[3/6] Generating Fortran dyndep file app\CMakeFiles\test_exe.dir\Fortran.dd
[4/7] Building Fortran object src\CMakeFiles\test_module.dir\test_module.f90.obj
[5/7] Building Fortran object app\CMakeFiles\test_exe.dir\test_exe.f90.obj
[6/7] Linking Fortran shared library src\test_module.dll
FAILED: src/test_module.dll src/test_module.lib
C:\WINDOWS\system32\cmd.exe /C "C:\WINDOWS\system32\cmd.exe /C ""C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E __create_def C:\Work\Fortran\dynamic_link_error\out\build\x64-release\src\CMakeFiles\test_module.dir\.\exports.def C:\Work\Fortran\dynamic_link_error\out\build\x64-release\src\CMakeFiles\test_module.dir\.\exports.def.objs && cd C:\Work\Fortran\dynamic_link_error\out\build\x64-release" && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_dll --intdir=src\CMakeFiles\test_module.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo src\CMakeFiles\test_module.dir\test_module.f90.obj -LD /Qoption,link,/machine:x64 /debug /INCREMENTAL -Qipo /Qoption,link,/DEF:src\CMakeFiles\test_module.dir\.\exports.def user32.lib -link /out:src\test_module.dll /implib:src\test_module.lib /pdb:test_module.dll.dbg /version:0.0 && cd ."
C:\Work\Fortran\dynamic_link_error\out\build\x64-release\EXEC : llvm-nm returned an error : nm: unrecognized option `--no-weak'
Usage: nm [option(s)] [file(s)]
List symbols in [file(s)] (a.out by default).
The options are:
-a, --debug-syms Display debugger-only symbols
-A, --print-file-name Print name of the input file before every symbol
-B Same as --format=bsd
-C, --demangle[=STYLE] Decode low-level symbol names into user-level names
The STYLE, if specified, can be `auto' (the default),
`gnu', `lucid', `arm', `hp', `edg', `gnu-v3', `java'
or `gnat'
--no-demangle Do not demangle low-level symbol names
-D, --dynamic Display dynamic symbols instead of normal symbols
--defined-only Display only defined symbols
-e (ignored)
-f, --format=FORMAT Use the output format FORMAT. FORMAT can be `bsd',
`sysv' or `posix'. The default is `bsd'
-g, --extern-only Display only external symbols
-l, --line-numbers Use debugging information to find a filename and
line number for each symbol
-n, --numeric-sort Sort symbols numerically by address
-o Same as -A
-p, --no-sort Do not sort the symbols
-P, --portability Same as --format=posix
-r, --reverse-sort Reverse the sense of the sort
--plugin NAME Load the specified plugin
-S, --print-size Print size of defined symbols
-s, --print-armap Include index for symbols from archive members
--size-sort Sort symbols by size
--special-syms Include special symbols in the output
--synthetic Display synthetic symbols as well
-t, --radix=RADIX Use RADIX for printing symbol values
--target=BFDNAME Specify the target object format as BFDNAME
-u, --undefined-only Display only undefined symbols

-X 32_64 (ignored)

@FILE Read options from FILE

-h, --help Display this information

-V, --version Display this program's version number



nm: supported targets: pe-i386 pei-i386 elf32-i386 elf32-little elf32-big plugin srec symbolsrec verilog tekhex binary ihex



ninja: build stopped: subcommand failed.

Build All failed.

[Barbara_P_Intel]

@ChrisC2, you wrote that you have the same issue on Linux. Can you please upload a .zip for the Linux version?

I ask because I see the .json file is all about Windows and ninja.

Or does that even matter? My skills are better with Linux.

[Barbara_P_Intel]

One more thing... When I use the .zip file you uploaded on Windows, it builds with ifort, not ifx. Please upload a reproducer for Windows that uses ifx.

I've been in touch with Intel's CMake engineer; he uploads Intel updates for CMake. He wrote that the MSVC generator ignores CMAKE_Fortran_COMPILER, you need to set the platform toolset.  For CMake 3.29, to use ifx you can use 

    cmake  -T "Intel C++ Compiler 2024,fortran=ifx" ..

Please share the exact CMake commands you are using.

[ChrisC2]

Barbara, thanks for your persistence on this.   First off, I was wrong about LInux.  I thought it showed similar behavior there, but I tried my simple reproducer on LInux and it worked fine.   Should note while it was using CMake the build system on Linux is Make.

To reproduce the error, in a IntelOneAPI command prompt for VS2022, in the directory the project is in:

cmake -B out --preset x64-release

cmake --build out

(If you don't specify the preset I also get iFort instead of ifx).  Just as a test, I downloaded the latest release version of CMake (3.29.2) and Ninja (v1.12) and tried to build using that version and get the same error.   

Next, I went and pulled the link commands the are being specified to link the exe, ran those commands manually, and the link process worked fine.   So as best I can tell the issue is in either CMake or Ninja in the way it packages the link commands?   

[Barbara_P_Intel]

Can you please do `cmake –build out -v` and share the output? 

ninja will print out all the commands it uses and we can see what is missing or incorrect.

[ChrisC2]

Sure.  I've run those commands, output below.   I've posted the first command output first.   Then I tried running the build command again, and showed a different error that may be more specific regarding undefined symbol. 

First run: 

C:\Work\Fortran\dynamic_link_error>cmake --build out -v
Change Dir: 'C:/Work/Fortran/dynamic_link_error/out'

Run Build Command(s): C:/PROGRA~1/MICROS~4/2022/PROFES~1/Common7/IDE/COMMON~1/MICROS~1/CMake/Ninja/ninja.exe -v
[1/8] C:\WINDOWS\system32\cmd.exe /C "C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe -fpp -Dtest_module_EXPORTS /W1 /nologo /fpp /libs:dll /threads /O3 /debug /arch:AVX2 /fp:fast=2 /Qprec-div- /Qopenmp /Qopt-report -Qipo -module:Modules -P C:\Work\Fortran\dynamic_link_error\src\test_module.f90 -Fisrc\CMakeFiles\test_module.dir\test_module.f90-pp.f90 && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E cmake_ninja_depends --tdi=src\CMakeFiles\test_module.dir\FortranDependInfo.json --lang=Fortran --src=src\CMakeFiles\test_module.dir\test_module.f90-pp.f90 --out=src\CMakeFiles\test_module.dir\test_module.f90-pp.f90 --dep=src\CMakeFiles\test_module.dir\test_module.f90-pp.f90.d --obj=src\CMakeFiles\test_module.dir\test_module.f90.obj --ddi=src\CMakeFiles\test_module.dir\test_module.f90.obj.ddi"
[2/8] C:\WINDOWS\system32\cmd.exe /C "C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe -fpp /W1 /nologo /fpp /libs:dll /threads /O3 /debug /arch:AVX2 /fp:fast=2 /Qprec-div- /Qopenmp /Qopt-report -Qipo -module:Modules -P C:\Work\Fortran\dynamic_link_error\app\test_exe.f90 -Fiapp\CMakeFiles\test_exe.dir\test_exe.f90-pp.f90 && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E cmake_ninja_depends --tdi=app\CMakeFiles\test_exe.dir\FortranDependInfo.json --lang=Fortran --src=app\CMakeFiles\test_exe.dir\test_exe.f90-pp.f90 --out=app\CMakeFiles\test_exe.dir\test_exe.f90-pp.f90 --dep=app\CMakeFiles\test_exe.dir\test_exe.f90-pp.f90.d --obj=app\CMakeFiles\test_exe.dir\test_exe.f90.obj --ddi=app\CMakeFiles\test_exe.dir\test_exe.f90.obj.ddi"
[3/8] "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E cmake_ninja_dyndep --tdi=src\CMakeFiles\test_module.dir\FortranDependInfo.json --lang=Fortran --dd=src\CMakeFiles\test_module.dir\Fortran.dd @SRC\CMakeFiles\test_module.dir\Fortran.dd.rsp
[4/8] "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E cmake_ninja_dyndep --tdi=app\CMakeFiles\test_exe.dir\FortranDependInfo.json --lang=Fortran --dd=app\CMakeFiles\test_exe.dir\Fortran.dd @app\CMakeFiles\test_exe.dir\Fortran.dd.rsp
[5/8] C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo /fpp -Dtest_module_EXPORTS -IC:\Work\Fortran\dynamic_link_error\src /W1 /nologo /fpp /libs:dll /threads /O3 /debug /arch:AVX2 /fp:fast=2 /Qprec-div- /Qopenmp /Qopt-report -Qipo -module:Modules /Fosrc\CMakeFiles\test_module.dir\test_module.f90.obj /Fd -c src\CMakeFiles\test_module.dir\test_module.f90-pp.f90
[6/8] C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo /fpp -IC:\Work\Fortran\dynamic_link_error\app /W1 /nologo /fpp /libs:dll /threads /O3 /debug /arch:AVX2 /fp:fast=2 /Qprec-div- /Qopenmp /Qopt-report -Qipo -module:Modules /Foapp\CMakeFiles\test_exe.dir\test_exe.f90.obj /Fd -c app\CMakeFiles\test_exe.dir\test_exe.f90-pp.f90
[7/8] C:\WINDOWS\system32\cmd.exe /C "C:\WINDOWS\system32\cmd.exe /C ""C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E __create_def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def.objs && cd C:\Work\Fortran\dynamic_link_error\out" && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_dll --intdir=src\CMakeFiles\test_module.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo src\CMakeFiles\test_module.dir\test_module.f90.obj -LD /Qoption,link,/machine:x64 /debug /INCREMENTAL -Qipo /Qoption,link,/DEF:src\CMakeFiles\test_module.dir\.\exports.def user32.lib -link /out:src\test_module.dll /implib:src\test_module.lib /pdb:test_module.dll.dbg /version:0.0 && cd ."
FAILED: src/test_module.dll src/test_module.lib
C:\WINDOWS\system32\cmd.exe /C "C:\WINDOWS\system32\cmd.exe /C ""C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E __create_def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def.objs && cd C:\Work\Fortran\dynamic_link_error\out" && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_dll --intdir=src\CMakeFiles\test_module.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo src\CMakeFiles\test_module.dir\test_module.f90.obj -LD /Qoption,link,/machine:x64 /debug /INCREMENTAL -Qipo /Qoption,link,/DEF:src\CMakeFiles\test_module.dir\.\exports.def user32.lib -link /out:src\test_module.dll /implib:src\test_module.lib /pdb:test_module.dll.dbg /version:0.0 && cd ."
llvm-nm returned an error: nm: unrecognized option `--no-weak'
Usage: nm [option(s)] [file(s)]
List symbols in [file(s)] (a.out by default).
The options are:
-a, --debug-syms Display debugger-only symbols
-A, --print-file-name Print name of the input file before every symbol
-B Same as --format=bsd
-C, --demangle[=STYLE] Decode low-level symbol names into user-level names
The STYLE, if specified, can be `auto' (the default),
`gnu', `lucid', `arm', `hp', `edg', `gnu-v3', `java'
or `gnat'
--no-demangle Do not demangle low-level symbol names
-D, --dynamic Display dynamic symbols instead of normal symbols
--defined-only Display only defined symbols
-e (ignored)
-f, --format=FORMAT Use the output format FORMAT. FORMAT can be `bsd',
`sysv' or `posix'. The default is `bsd'
-g, --extern-only Display only external symbols
-l, --line-numbers Use debugging information to find a filename and
line number for each symbol
-n, --numeric-sort Sort symbols numerically by address
-o Same as -A
-p, --no-sort Do not sort the symbols
-P, --portability Same as --format=posix
-r, --reverse-sort Reverse the sense of the sort
--plugin NAME Load the specified plugin
-S, --print-size Print size of defined symbols
-s, --print-armap Include index for symbols from archive members
--size-sort Sort symbols by size
--special-syms Include special symbols in the output
--synthetic Display synthetic symbols as well
-t, --radix=RADIX Use RADIX for printing symbol values
--target=BFDNAME Specify the target object format as BFDNAME
-u, --undefined-only Display only undefined symbols
-X 32_64 (ignored)
@FILE Read options from FILE
-h, --help Display this information
-V, --version Display this program's version number

nm: supported targets: pe-i386 pei-i386 elf32-i386 elf32-little elf32-big plugin srec symbolsrec verilog tekhex binary ihex

ninja: build stopped: subcommand failed.

Second run:

C:\Work\Fortran\dynamic_link_error>cmake --build out -v
Change Dir: 'C:/Work/Fortran/dynamic_link_error/out'

Run Build Command(s): C:/PROGRA~1/MICROS~4/2022/PROFES~1/Common7/IDE/COMMON~1/MICROS~1/CMake/Ninja/ninja.exe -v
[1/2] C:\WINDOWS\system32\cmd.exe /C "C:\WINDOWS\system32\cmd.exe /C ""C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E __create_def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def.objs && cd C:\Work\Fortran\dynamic_link_error\out" && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_dll --intdir=src\CMakeFiles\test_module.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo src\CMakeFiles\test_module.dir\test_module.f90.obj -LD /Qoption,link,/machine:x64 /debug /INCREMENTAL -Qipo /Qoption,link,/DEF:src\CMakeFiles\test_module.dir\.\exports.def user32.lib -link /out:src\test_module.dll /implib:src\test_module.lib /pdb:test_module.dll.dbg /version:0.0 && cd ."
[2/2] C:\WINDOWS\system32\cmd.exe /C "cd . && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=app\CMakeFiles\test_exe.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo app\CMakeFiles\test_exe.dir\test_exe.f90.obj /Qoption,link,/machine:x64 /debug /INCREMENTAL /Qoption,link,/subsystem:console -Qipo src\test_module.lib user32.lib /link /out:app\test_exe.exe /implib:app\test_exe.lib /pdb:test_exe.exe.dbg /version:0.0 && cd ."
FAILED: app/test_exe.exe
C:\WINDOWS\system32\cmd.exe /C "cd . && "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E vs_link_exe --intdir=app\CMakeFiles\test_exe.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100220~1.0\x64\mt.exe --manifests -- C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo app\CMakeFiles\test_exe.dir\test_exe.f90.obj /Qoption,link,/machine:x64 /debug /INCREMENTAL /Qoption,link,/subsystem:console -Qipo src\test_module.lib user32.lib /link /out:app\test_exe.exe /implib:app\test_exe.lib /pdb:test_exe.exe.dbg /version:0.0 && cd ."
LINK Pass 1: command "C:\PROGRA~2\Intel\oneAPI\compiler\latest\bin\ifx.exe /nologo app\CMakeFiles\test_exe.dir\test_exe.f90.obj /Qoption,link,/machine:x64 /debug /INCREMENTAL /Qoption,link,/subsystem:console -Qipo src\test_module.lib user32.lib /link /out:app\test_exe.exe /implib:app\test_exe.lib /pdb:test_exe.exe.dbg /version:0.0 /MANIFEST /MANIFESTFILE:app\CMakeFiles\test_exe.dir/intermediate.manifest app\CMakeFiles\test_exe.dir/manifest.res" failed (exit code 1) with the following output:
lld-link: error: undefined symbol: TEST_MODULE_mp_TEST_FUNC
>>> referenced by 4024446.i90
>>> app\CMakeFiles\test_exe.dir\test_exe.f90.obj
ninja: build stopped: subcommand failed.

[ChrisC2]

C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\.\exports.def

The path to the exports files looks suspect.   The actual path is:

C:\Work\Fortran\dynamic_link_error\out\src\CMakeFiles\test_module.dir\exports.def

[Barbara_P_Intel]

Thanks for the additional info, @ChrisC2. This issue may be related to your environment. Maybe the PATH? Do you have CLANG products installed?

The version of llvm-nm distributed by Intel is in C:\Program Files (x86)\Intel\oneAPI\compiler\latest\bin\compiler\llvm-nm.exe.

We noticed that the -help output is a bit different between what you posted and what we get from the Intel distribution

.

[ChrisC2]

Quick follow-up to this topic to document what I've found.  I do have an install of Cygwin installed with the bin directory in my Path, which Barbara noted above.   This was confusing, but once this was removed, the errors changed to a consistent lack of export symbols for the linker.   Doing some more digging, I believe the github issue below describes in detail the issue that caused this.  

https://github.com/luxonis/depthai-core/issues/334

In short, CMake has a flag, CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS which is very handy when building shared libraries on Windows.   CMake scans the obj files to generate a def list.  However that doesn't work with ipo enabled, and Cmake generates emtpy def files.  As a result, I"ve gone back to using !DIR$ ATTRIBUTES DLLEXPORT for this particular project, which seems to have corrected this.