Cross compile support?

[csonsino]

Is cross compiling this project expected to work? (v1.0.25 / master 447b8e1bc802107f7877620980008eb7bd5e299c)

I'm trying to cross compile lsp-plugins (v1.2.17) for aarch64 on an x86-64 machine, but it's failing with this error:

...
make[4]: Entering directory '<base_dir>/lsp-plugins/modules/lsp-runtime-lib'
make[4]: Leaving directory '<base_dir>/lsp-plugins/modules/lsp-runtime-lib'
  aarch64-poky-linux-g++  -march=armv8-a+crc+crypto -mbranch-protection=standard -fstack-protector-strong  -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=<sysroot_dir>  [lsp-plugin-fw] respack
  aarch64-poky-linux-g++  -march=armv8-a+crc+crypto -mbranch-protection=standard -fstack-protector-strong  -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=<sysroot_dir>  [lsp-plugin-fw] repository
  <base_dir>/lsp-plugins/.build/host/lsp-plugin-fw/utils-bin/repository
aarch64-binfmt-P: Could not open '/lib/ld-linux-aarch64.so.1': No such file or directory
make[3]: *** [Makefile:1323: resources] Error 255
make[3]: Leaving directory '<base_dir>/lsp-plugins/modules/lsp-plugin-fw/src'
make[2]: *** [Makefile:67: all] Error 2
make[2]: Leaving directory '<base_dir>/lsp-plugins/modules/lsp-plugin-fw'
make[1]: *** [Makefile:145: all] Error 2
make[1]: Leaving directory '<base_dir>/lsp-plugins/src'
make: *** [Makefile:68: all] Error 2

I'm trying to start simple and build only the lv2 plugins for now, specifically without the UI dependencies, so I'm using this make config:

VERBOSE=1 DEBUG=1 ARCHITECTURE=aarch64 make config FEATURES="lv2"

The /lib/ld-linux-aarch64.so.1 library that it cannot seem to find does exist in my sysroot directory, but I don't really understand what's going on with respect to respack and repository. It seems like those are binaries that are being cross compiled to aarch64, but then invoked during the build in the x86-64 context? If that's the case then I wouldn't expect this build to be compatible with a cross compiling procedure unless there is some combination of host/target/build arguments that I'm failing to set?

[sadko4u]

Hello! The respack and repository tools like others are compile-time generated tools that process and generate built-in resources that are then linked with the binaries. AFAIR these tools are built a bit differently as it is reflected in the 'HOST_' prefix of variables used to store their names and arguments. They also use HOST_CXXFLAGS instead of CXXFLAGS variables etc. But at this moment the HOST_CXXFLAGS is defaulted to CXXFLAGS which is computed according to the ARCHTECTURE setting.

I think you can help with cross-compilation if you dig into make files.

[csonsino]

Things seem to go a bit better if I set HOST_ variables corresponding to my build machine, until the $(HOST_UTL_RESPACK) task. $(HOST_UTL_RESPACK_OBJS) references .o files under .build/host/..., and $(HOST_UTL_RESPACK_LIBS) references .o files under .build/target/..., which happen to link okay when host and target are the same but not so well when they are different. Something seems a bit odd about the $(HOST_UTL_RESPACK_LIBS) objects actually being under the .build/target directory.

[sadko4u]

I've just updated source code and sub-projects and additionally optimized the build, so you need to pass CROSS_COMPILE=1 option to make config if you want to cross-compile source code. Please try to build plugins from the devel branch now.

[csonsino]

There is a host/target issue with the A/B Tester plugin, but if I disable that one plugin then it looks like I'm able to get a successful cross compile build. I'll have to do a bit more work to validate that the .so is usable on the target device, but this is great progress. Thanks so much!

[csonsino]

After looking at this a bit more I don't think that the "modules/lsp-plugins-*" plugins are cross compiling (I'm seeing "error adding symbols: file in wrong format" when linking). Will see if I can figure it out.

[csonsino]

I think that this is working for me (adding $(HOST) in a few places): <lsp-plugins>/modules/lsp-plugins-ab-tester$ git diff

diff --git a/src/Makefile b/src/Makefile
index 53214de..bc85e59 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -90,7 +90,7 @@ XOBJ_TEST               = $(if $(OBJ_TEST),$(OBJ_TEST),$(OBJ_STUB))
 CXX_FILE                = $(patsubst $(ARTIFACT_BIN)/%.o,%.cpp, $(@))
 DEP_FILE                = $(patsubst %.o,%.d, $(@))

-CFLAGS_DEPS             = $(foreach dep, $(call uniq, $(DEPENDENCIES)), $(if $($(dep)_CFLAGS), $($(dep)_CFLAGS)))
+CFLAGS_DEPS             = $(foreach dep, $(call uniq, $(DEPENDENCIES)), $(if $($(HOST)$(dep)_CFLAGS), $($(HOST)$(dep)_CFLAGS)))
 BUILD_ALL               = $(ARTIFACT_LIB) $(ARTIFACT_SLIB) $(ARTIFACT_PC)

 ifeq ($(TEST), 1)
@@ -114,14 +114,14 @@ $(CXX_SRC_STUB):
        echo "#include <stdio.h>" > $(CXX_SRC_STUB)

 $(OBJ_STUB): $(CXX_SRC_STUB)
-       echo "  $(CXX)  [$(ARTIFACT_NAME)] $(CXX_FILE)"
+       echo "  $($(HOST)CXX)  [$(ARTIFACT_NAME)] $(CXX_FILE)"
        mkdir -p $(dir $@)
-       $(CXX) -o $(@) -c $(CXX_SRC_STUB) -fPIC $(CXXFLAGS) $(ARTIFACT_MFLAGS) $(EXT_FLAGS) $(INCLUDE) $(CFLAGS_DEPS) -MMD -MP -MF $(DEP_FILE) -MT $(@)
+       $($(HOST)CXX) -o $(@) -c $(CXX_SRC_STUB) -fPIC $($(HOST)CXXFLAGS) $(ARTIFACT_MFLAGS) $(EXT_FLAGS) $(INCLUDE) $(CFLAGS_DEPS) -MMD -MP -MF $(DEP_FILE) -MT $(@)

 $(OBJ):
-       echo "  $(CXX)  [$(ARTIFACT_NAME)] $(CXX_FILE)"
+       echo "  $($(HOST)CXX)  [$(ARTIFACT_NAME)] $(CXX_FILE)"
        mkdir -p $(dir $@)
-       $(CXX) -o $(@) -c $(CXX_FILE) -fPIC $(CXXFLAGS) $(ARTIFACT_MFLAGS) $(EXT_FLAGS) $(INCLUDE) $(CFLAGS_DEPS) -MMD -MP -MF $(DEP_FILE) -MT $(@)
+       $($(HOST)CXX) -o $(@) -c $(CXX_FILE) -fPIC $($(HOST)CXXFLAGS) $(ARTIFACT_MFLAGS) $(EXT_FLAGS) $(INCLUDE) $(CFLAGS_DEPS) -MMD -MP -MF $(DEP_FILE) -MT $(@)

 # Linking targets
 $(ARTIFACT_OBJ_META): $(XOBJ_MAIN_META)

I'm happy to do a PR if you really want, but this change has to be applied in each of the modules/lsp-plugins-<plugin>/src/Makefile so that would be quite a lot of PRs...

[sadko4u]

Don't do PR for all plugins. I'll add this patch to lsp-plugins-plugin-template and propagate it to all plugins.

[csonsino]

I'm trying to resolve one problem with lsp-plugins-crossover during metadata validation, but not sure if this is caused by the above patch. As far as I can tell the rest of the plugins work with that patch:

g++  -march=x86-64 -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security  [lsp-plugin-fw] validator
Validating plugin metadata
Port id='scl' clashes another port id='scl' for plugin uid='compressor_mono'
Port id='scl_l' clashes another port id='scl_l' for plugin uid='compressor_lr'
Port id='scl_r' clashes another port id='scl_r' for plugin uid='compressor_lr'
Port id='scl' clashes another port id='scl' for plugin uid='sc_compressor_mono'
Port id='scl_l' clashes another port id='scl_l' for plugin uid='sc_compressor_lr'
Port id='scl_r' clashes another port id='scl_r' for plugin uid='sc_compressor_lr'
Overall validation statistics: plugins=182, warnings=0, errors=6

make[3]: *** [Makefile:1332: validate] Error 38

[sadko4u]

I've propagated all changes to all plugins, you can try to update source tree.

[sadko4u]

With compressor: it seems to be a regression that I missed yesterday when adding new functions: https://github.com/lsp-plugins/lsp-plugins-compressor/actions/runs/10909278249/job/30277129316#step:8:3751

Just committed changes that fix the problem for compressor.

[csonsino]

Latest devel changes look good to me. All plugins are cross compiling and the (lv2) library & manifest are usable on my target platform. Flanger is flanging :)

[sadko4u]

Can you give any instructions of how to cross-compile the package of plugins or add some instructions here?

[csonsino]

Done (https://github.com/lsp-plugins/lsp-plugins/pull/441) Feel free to modify the text in any way you like.

[csonsino]

Available in lsp-plugins 1.2.18. Thanks!