examples : add dl to the list of libraries linked (#2875)

* examples : add dl to the list of libraries linked

This commit adds the dynamic linker library to the list of libraries
linked by the examples.

The motivation for this change is that when building the examples on
ubuntu 20.04, which uses GCC 9.4.0, the dynamic linker requires
explicit linking or the following error is generated:
```console
[ 64%] Linking CXX executable ../../bin/whisper-cli
cd /app/whisper.cpp/build/examples/cli && /usr/bin/cmake -E cmake_link_script CMakeFiles/whisper-cli.dir/link.txt --verbose=1
/usr/bin/c++  -O3 -DNDEBUG   CMakeFiles/whisper-cli.dir/cli.cpp.o  -o ../../bin/whisper-cli  -Wl,-rpath,/app/whisper.cpp/build/src:/app/whisper.cpp/build/ggml/src: ../libcommon.a ../../src/libwhisper.so.1.7.4 -pthread ../../ggml/src/libggml.so ../../ggml/src/libggml-cpu.so ../../ggml/src/libggml-base.so
/usr/bin/ld: ../libcommon.a(common-whisper.cpp.o): undefined reference to symbol 'dlclose@@GLIBC_2.2.5'
/usr/bin/ld: /lib/x86_64-linux-gnu/libdl.so.2: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[2]: *** [examples/cli/CMakeFiles/whisper-cli.dir/build.make:89: bin/whisper-cli] Error 1
make[2]: Leaving directory '/app/whisper.cpp/build'
make[1]: *** [CMakeFiles/Makefile2:433: examples/cli/CMakeFiles/whisper-cli.dir/all] Error 2
make[1]: Leaving directory '/app/whisper.cpp/build'
make: *** [Makefile:130: all] Error 2
```

Resolves: https://github.com/ggerganov/whisper.cpp/issues/2854

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index e1b083d352b72b031482fde18f96be46f7c5104d..e4265affe972577d114d645019626dc64bde13f7 100644 (file)
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -61,7 +61,7 @@ add_library(${TARGET} STATIC
 
 include(DefaultTargetOptions)
 
-target_link_libraries(${TARGET} PRIVATE whisper ${COMMON_EXTRA_LIBS})
+target_link_libraries(${TARGET} PRIVATE whisper ${COMMON_EXTRA_LIBS} ${CMAKE_DL_LIBS})
 
 set_target_properties(${TARGET} PROPERTIES POSITION_INDEPENDENT_CODE ON)
 set_target_properties(${TARGET} PROPERTIES FOLDER "libs")