Remarks for Debian

[gabrieldevillers]

Thanks for this project, very useful demo.

I had trouble building the file DNNE/test/ExportingAssembly/obj/Debug/net5.0/dnne/ExportingAssembly.g.c
The error were:

platform.c(222,5): error GCEFF6793: use of undeclared identifier 'Dl_info'
platform.c(223,47): error GCEFF6793: use of undeclared identifier 'info'
[...]

The command was: Building native export: "clang" -g -O0 -shared -fpic -D DNNE_ASSEMBLY_NAME=ExportingAssembly -I "/home/gabriel/.nuget/packages/dnne/1.0.3/tools/platform" -I "/home/gabriel/dev/dotnet-sdk/dotnet-sdk-5.0.100-preview.6.20309.18-linux-x64/packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native" -lstdc++ -o "/home/gabriel/dev/DNNE/test/ExportingAssembly/obj/Debug/net5.0/dnne/bin/ExportingAssemblyNE.so" "/home/gabriel/dev/dotnet-sdk/dotnet-sdk-5.0.100-preview.6.20309.18-linux-x64/packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native/libnethost.a" "/home/gabriel/dev/DNNE/test/ExportingAssembly/obj/Debug/net5.0/dnne/ExportingAssembly.g.c" "/home/gabriel/.nuget/packages/dnne/1.0.3/tools/platform/platform.c"

The solution I found was to add #define __USE_GNU 1 before #include <dlfcn.h> in platform.c (I modified /home/gabriel/.nuget/packages/dnne/1.0.3/tools/platform/platform.c because I failed to find the good commands to regen/override/bypass the server the current nuget package).

Also I failed to understand what should provide the function get_hostfxr_path in platform.c (link time problem) so I changed:

    // Discover the path to hostfxr.
    char_t buffer[DNNE_MAX_PATH];
    size_t buffer_size = DNNE_ARRAY_SIZE(buffer);
    int rc = get_hostfxr_path(buffer, &buffer_size, NULL);
    if (is_failure(rc))
        noreturn_runtime_load_failure(rc);


    Load hostfxr and get desired exports.
    void* lib = load_library(buffer);

into:

    void* lib = load_library("libhostfxr.so");

and then I added the directory containing libhostfxr.so to LD_LIBRARY_PATH.

[AaronRobinsonMSFT]

@gabrieldevillers Thanks for reporting this issue. I will admit I didn't do a lot of linux validation. I focused on Windows and macOS because that is what I had easily available. I did run a simple sanity check on Ubuntu 16.04 initially but nothing since then.

The solution I found was to add #define __USE_GNU 1 before #include <dlfcn.h> in platform.c

Good to know. I will check that out and see what I am missing in this scenario.

Also I failed to understand what should provide the function get_hostfxr_path in platform.c (link time problem) so I changed:

The link time failure is the issue here. The libnethost.a is the tool that helps find the libhostfxr.so binary, so if linking failed that is the root issue. Your solution is correct, but shouldn't be needed if libnethost.a is properly linked in.

Based on the command line the following library should be included: "/home/gabriel/dev/dotnet-sdk/dotnet-sdk-5.0.100-preview.6.20309.18-linux-x64/packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native/libnethost.a". Can you help me out and verify this file exists? If so making that link properly as a static lib should solve the second issue.

[AaronRobinsonMSFT]

The solution I found was to add #define __USE_GNU 1 before #include <dlfcn.h> in platform.c

Good to know. I will check that out and see what I am missing in this scenario.

@gabrieldevillers Boo. This was my issue. I don't recall how I validated this on Linux. It is properly documented here and here. I will see about validating this using #define _GNU_SOURCE.

[gabrieldevillers]

Based on the command line the following library should be included: "/home/gabriel/dev/dotnet-sdk/dotnet-sdk-5.0.100-preview.6.20309.18-linux-x64/packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native/libnethost.a". Can you help me out and verify this file exists? If so making that link properly as a static lib should solve the second issue.

find -iname "*libnethost*" in dotnet-sdk-5.0.100-preview.6.20309.18-linux-x64 gives:

./shared/Microsoft.NETCore.App/5.0.0-preview.6.20305.6/libnethost.a
./packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native/libnethost.a
./packs/Microsoft.NETCore.App.Host.linux-x64/5.0.0-preview.6.20305.6/runtimes/linux-x64/native/libnethost.so

I misremembered, I do not get a link time failure but a runtime failure:

Loading library: ../ExportingAssembly/bin/Debug/net5.0/ExportingAssemblyNE.so
mod is: 0x5585ad23a6f0
./ImportingProcess: symbol lookup error: ../ExportingAssembly/bin/Debug/net5.0/ExportingAssemblyNE.so: undefined symbol: get_hostfxr_path

Also I forgot to tell you that I also had to add this to ImportingProcess/CMakeLists.txt:

target_link_libraries(ImportingProcess dl pthread)