From d5cc27ee4dc67fcb3e36b40bd5d5b95ff39470e7 Mon Sep 17 00:00:00 2001
From: Daniel Bevenius <daniel.bevenius@gmail.com>
Date: Fri, 14 Mar 2025 04:42:20 +0100
Subject: [PATCH] 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
---
 examples/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index e1b083d3..e4265aff 100644
--- 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")