Linker fails to find filament::Material::Builder::build

[DreiDe]

I use the provided Makefile to link against the static filament libraries:

FILAMENT_LIBS=-lfilament -lbackend -lbluegl -lbluevk -lfilabridge -lfilaflat -lutils -lgeometry -lsmol-v -lvkshaders -libl
CC=clang++

main: main.o
	$(CC) -Llib/x86_64/ main.o $(FILAMENT_LIBS) -lpthread -lc++ -ldl -o main

main.o: main.cpp
	$(CC) -Iinclude/ -std=c++17 -pthread -c main.cpp

clean:
	rm -f main main.o

.PHONY: clean

This works fine unless I call Material* material = Material::Builder().build(*engine);
While this does compile fine, the linker complains:

main.cpp:(.text+0x13f): undefined reference to `filament::Material::Builder::build(filament::Engine&)'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I have included the filament/Material.h and filament/Engine.h files. What could be the issue here?

When analyzing the binary with
` nm -C libfilament.a | grep 'filament::Material::Builder::build'``` the symbol is found:

                 U filament::Material::Builder::build(filament::Engine&) const
                 U filament::Material::Builder::build(filament::Engine&) const
0000000000000000 T filament::Material::Builder::build(filament::Engine&) const
                 U filament::Material::Builder::build(filament::Engine&) const

[show50726]

I tried the same thing on my machine and I did not encounter this issue.

Could you share about the setup of your compiler, the filament release version, or even the main.cpp you're using?

[DreiDe]

Compiler Version is clang 14.0.0 on Ubuntu 22.04.5 LTS with compilation target x86_64-pc-linux-gnu. I'm running GLIBC_2.35 so I had to compile the library from source via build.sh as the prebuilt libraries are built against GLIBC_2.38.

On a cloud server running Ubuntu 24 with GLIBC_2.40 the issue did not occur when using the prebuilt binaries.

This is a minimum reproducible main.cpp example.

#include <filament/Engine.h>
#include <filament/Material.h>

#include <vector>
#include <fstream>

using namespace filament;

int main() {
    // Initialize Filament Engine
    Engine* engine = Engine::create(Engine::Backend::OPENGL);
    Material* material = Material::Builder().build(*engine);

    return 0;
}

[show50726]

Could you check if both libc++ and libc++abi have a higher version than 14?

[DreiDe]

This is what dpkg -l | grep libc++ reports:

ii  libc++-14-dev:amd64                                         1:14.0.0-1ubuntu1.1                                     amd64        LLVM C++ Standard library (development files)
ii  libc++-dev:amd64                                            1:14.0-55~exp2                                          amd64        LLVM C++ Standard library (development files)
ii  libc++1-14:amd64                                            1:14.0.0-1ubuntu1.1                                     amd64        LLVM C++ Standard library
ii  libc++abi-14-dev:amd64                                      1:14.0.0-1ubuntu1.1                                     amd64        LLVM low level support for a standard C++ library (development files)
ii  libc++abi-dev:amd64                                         1:14.0-55~exp2                                          amd64        LLVM low level support for a standard C++ library (development files)
ii  libc++abi1-14:amd64                                         1:14.0.0-1ubuntu1.1                                     amd64        LLVM low level support for a standard C++ library

[show50726]

I tried to setup a docker environment and align everything with your settings, but I'm not able to reproduce this issue.
It seems this problem is specific to your compiler or build situation.