Check for -lexecinfo on FreeBSD, instead of -ldl

CMakeLists.txt

@@ -22,6 +22,21 @@ include(ECMPoQmTools)
 find_package(Cargo REQUIRED)
 find_package(Rust REQUIRED)
 
+# Runtime information library -- dl on Debian, execinfo on FreeBSD.
+# This quiets a warning from rustc about linking to native artifacts.
+if (CMAKE_SYSTEM MATCHES "FreeBSD")
+    find_library(DL_LIBRARY execinfo)
+else()
+    find_library(DL_LIBRARY dl)
+endif()
+
+# It would be neater to use set_package_properties() here and to
+# rely on feature_summary(), below, but that entails using find_package()
+# and moving this whole thing into a Find-module, which is over-wrought.
+if (NOT DL_LIBRARY)
+    message(FATAL_ERROR "No runtime information library (-ldl or -lexecinfo)")
+endif()
+
 # Find Qt modules
 find_package(Qt5 ${QT_MIN_VERSION} CONFIG
     REQUIRED COMPONENTS

demo/CMakeLists.txt

@@ -25,7 +25,7 @@ add_custom_command(
 add_custom_target(rust_target DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/rust/${RUST_TARGET_DIR}/librust.a")
 
 list(APPEND DemoLibs "${CMAKE_CURRENT_SOURCE_DIR}/rust/${RUST_TARGET_DIR}/librust.a")
-list(APPEND DemoLibs Qt5::Widgets Qt5::Svg pthread dl)
+list(APPEND DemoLibs Qt5::Widgets Qt5::Svg pthread ${DL_LIBRARY})
 if (Qt5Quick_FOUND)
     list(APPEND DemoLibs Qt5::Quick)
 endif()

tests/CMakeLists.txt

@@ -40,7 +40,7 @@ function(rust_test NAME DIRECTORY)
         Qt5::Core
         Qt5::Test
         "${DIR}/${RUST_TARGET_DIR}/librust.a"
-        pthread dl
+        pthread ${DL_LIBRARY}
     )
     set_property(TARGET ${NAME}
         APPEND PROPERTY AUTOGEN_TARGET_DEPENDS "${SRC}/${NAME}_rust.h"