Dynamically load libudev in linux-hidraw backend

.cirrus.yml

@@ -1,7 +1,7 @@
 alpine_task:
         container:
                 image: alpine:latest
-        install_script: apk add autoconf automake g++ gcc libusb-dev libtool linux-headers eudev-dev make musl-dev
+        install_script: apk add autoconf automake g++ gcc libusb-dev libtool linux-headers eudev-libs make musl-dev
         script:
                 - ./bootstrap
                 - ./configure || { cat config.log; exit 1; }

.github/workflows/builds.yml

@@ -125,19 +125,22 @@ jobs:
     - name: Install dependencies
       run: |
         sudo apt update
-        sudo apt install autoconf automake libudev-dev libusb-1.0-0-dev pkg-config python3-pip ninja-build
+        sudo apt install autoconf automake libudev1 libusb-1.0-0-dev pkg-config python3-pip ninja-build
         sudo -H pip3 install meson
     - name: Configure CMake
       run: |
         rm -rf build install
-        cmake -B build/shared -S hidapisrc -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_ENABLE_ASAN=ON -DCMAKE_INSTALL_PREFIX=install/shared -DHIDAPI_BUILD_HIDTEST=ON -DHIDAPI_WITH_TESTS=ON "-DCMAKE_C_FLAGS=${GNU_COMPILE_FLAGS}"
-        cmake -B build/static -S hidapisrc -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_ENABLE_ASAN=ON -DCMAKE_INSTALL_PREFIX=install/static -DBUILD_SHARED_LIBS=FALSE -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${GNU_COMPILE_FLAGS}"
+        cmake -B build/shared -S hidapisrc -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_ENABLE_ASAN=ON -DHIDAPI_WITH_TESTS=ON -DCMAKE_INSTALL_PREFIX=install/shared -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${GNU_COMPILE_FLAGS}"
+        cmake -B build/static -S hidapisrc -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_ENABLE_ASAN=ON -DHIDAPI_WITH_TESTS=ON -DCMAKE_INSTALL_PREFIX=install/static -DBUILD_SHARED_LIBS=FALSE -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${GNU_COMPILE_FLAGS}"
     - name: Build CMake Shared
       working-directory: build/shared
       run: make install
     - name: Build CMake Static
       working-directory: build/static
       run: make install
+    - name: Test CMake Static
+      working-directory: build/static
+      run: ctest --output-on-failure
     - name: Check pkg-config package
       run: |
         autoreconf --install --force hidapisrc/tests/pkg-config
@@ -581,12 +584,12 @@ jobs:
         path: hidapisrc
     - name: Install dependencies
       run: |
-        apk add gcc musl-dev autoconf automake libtool eudev-dev libusb-dev linux-headers cmake ninja make
+        apk add gcc musl-dev autoconf automake libtool eudev-libs libusb-dev linux-headers cmake ninja make
     - name: Configure CMake
       run: |
         rm -rf build install
-        cmake -B build/shared-cmake -S hidapisrc -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=install/shared-cmake -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${ALPINE_COMPILE_FLAGS}"
-        cmake -B build/static-cmake -S hidapisrc -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_INSTALL_PREFIX=install/static-cmake -DBUILD_SHARED_LIBS=FALSE -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${ALPINE_COMPILE_FLAGS}"
+        cmake -B build/shared-cmake -S hidapisrc -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_WITH_TESTS=ON -DCMAKE_INSTALL_PREFIX=install/shared-cmake -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${ALPINE_COMPILE_FLAGS}"
+        cmake -B build/static-cmake -S hidapisrc -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_WITH_TESTS=ON -DCMAKE_INSTALL_PREFIX=install/static-cmake -DBUILD_SHARED_LIBS=FALSE -DHIDAPI_BUILD_HIDTEST=ON "-DCMAKE_C_FLAGS=${ALPINE_COMPILE_FLAGS}"
     - name: Configure Automake
       working-directory: hidapisrc
       run: |
@@ -595,9 +598,15 @@ jobs:
     - name: Build CMake Shared
       working-directory: build/shared-cmake
       run: ninja install
+    - name: Test CMake Shared
+      working-directory: build/shared-cmake
+      run: ctest --output-on-failure
     - name: Build CMake Static
       working-directory: build/static-cmake
       run: ninja install
+    - name: Test CMake Static
+      working-directory: build/static-cmake
+      run: ctest --output-on-failure
     - name: Build Automake
       working-directory: hidapisrc
       run: |

.github/workflows/checks.yml

@@ -141,7 +141,7 @@ jobs:
     - name: Install dependencies
       run: |
         sudo apt update
-        sudo apt install libudev-dev libusb-1.0-0-dev ninja-build
+        sudo apt install libudev1 libusb-1.0-0-dev ninja-build
     - name: Configure
       run: |
         cmake -B build -S src -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DHIDAPI_WITH_TESTS=ON -DHIDAPI_BUILD_HIDTEST=ON -DCMAKE_C_COMPILER=gcc

BUILD.md

@@ -45,14 +45,14 @@ Regardless of what build system you choose to use, there are specific dependenci
 ### Linux:
 
 Depending on which backend you're going to build, you'll need to install
-additional development packages. For `linux/hidraw` backend, you need a
-development package for `libudev`. For `libusb` backend, naturally, you need
-`libusb` development package.
+additional packages. The `linux/hidraw` backend loads `libudev` dynamically,
+so it only needs the runtime library. The `libusb` backend needs the `libusb`
+development package.
 
 On Debian/Ubuntu systems these can be installed by running:
 ```sh
-# required only by hidraw backend
-sudo apt install libudev-dev
+# required at runtime by the hidraw backend
+sudo apt install libudev1
 # required only by libusb backend
 sudo apt install libusb-1.0-0-dev
 ```

configure.ac

@@ -28,6 +28,8 @@ PKG_PROG_PKG_CONFIG
 
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
+HIDAPI_HIDRAW_PRIVATE_LIBS=
+
 hidapi_lib_error() {
 	echo ""
 	echo "  Library $1 was not found on this system."
@@ -57,9 +59,13 @@ case $host in
 	threads="pthreads"
 
 	# HIDAPI/hidraw libs
-	PKG_CHECK_MODULES([libudev], [libudev], true, [hidapi_lib_error libudev])
-	LIBS_HIDRAW_PR="${LIBS_HIDRAW_PR} $libudev_LIBS"
-	CFLAGS_HIDRAW="${CFLAGS_HIDRAW} $libudev_CFLAGS"
+	hidapi_saved_LIBS="$LIBS"
+	AC_SEARCH_LIBS([dlopen], [dl], [], [hidapi_lib_error libdl])
+	if test "x$ac_cv_search_dlopen" != "xnone required"; then
+		LIBS_HIDRAW_PR="${LIBS_HIDRAW_PR} ${ac_cv_search_dlopen}"
+		HIDAPI_HIDRAW_PRIVATE_LIBS="${ac_cv_search_dlopen}"
+	fi
+	LIBS="$hidapi_saved_LIBS"
 
 	# HIDAPI/libusb libs
 	AC_CHECK_LIB([rt], [clock_gettime], [LIBS_LIBUSB_PRIVATE="${LIBS_LIBUSB_PRIVATE} -lrt"], [hidapi_lib_error librt])
@@ -243,45 +249,54 @@ m4_define([HIDAPI_CONFIGURE_BACKEND_PC], [
 			-e "s|@HIDAPI_BACKEND_NAME@|$2|g" \
 			-e "s|@HIDAPI_BACKEND_DESCRIPTION@|$3|g" \
 			-e "s|@HIDAPI_BACKEND_LIBRARY_NAME@|$4|g" \
+			-e "s|@HIDAPI_BACKEND_PRIVATE_LIBS@|$5|g" \
 			"$1" > "$1.tmp" &&
 		mv "$1.tmp" "$1"
-	], [$5])
+	], [$6])
 ])
 
 HIDAPI_LIB_NAME=hidapi
 HIDAPI_LIBUSB_LIB_NAME=hidapi
+HIDAPI_PRIVATE_LIBS=
 if test "x$os" = "xlinux"; then
 	HIDAPI_LIB_NAME=hidapi-hidraw
 	HIDAPI_LIBUSB_LIB_NAME=hidapi-libusb
+	HIDAPI_PRIVATE_LIBS="$HIDAPI_HIDRAW_PRIVATE_LIBS"
 	HIDAPI_CONFIGURE_BACKEND_PC(
 		[pc/hidapi-hidraw.pc],
 		[hidapi-hidraw],
 		[C Library for USB/Bluetooth HID device access from Linux, Mac OS X, FreeBSD, and Windows. This is the hidraw implementation.],
-		[hidapi-hidraw])
+		[hidapi-hidraw],
+		[$HIDAPI_HIDRAW_PRIVATE_LIBS],
+		[HIDAPI_HIDRAW_PRIVATE_LIBS="$HIDAPI_HIDRAW_PRIVATE_LIBS"])
 elif test "x$os" = "xdarwin"; then
 	HIDAPI_CONFIGURE_BACKEND_PC(
 		[pc/hidapi-darwin.pc],
 		[hidapi-darwin],
 		[C Library for USB/Bluetooth HID device access from Linux, Mac OS X, FreeBSD, and Windows. This is the Darwin implementation.],
-		[hidapi])
+		[hidapi],
+		[])
 elif test "x$os" = "xwindows"; then
 	HIDAPI_CONFIGURE_BACKEND_PC(
 		[pc/hidapi-winapi.pc],
 		[hidapi-winapi],
 		[C Library for USB/Bluetooth HID device access from Linux, Mac OS X, FreeBSD, and Windows. This is the WinAPI implementation.],
-		[hidapi])
+		[hidapi],
+		[])
 fi
 if test "x$os" != "xdarwin" && test "x$os" != "xwindows"; then
 	HIDAPI_CONFIGURE_BACKEND_PC(
 		[pc/hidapi-libusb.pc],
 		[hidapi-libusb],
 		[C Library for USB HID device access from Linux, Mac OS X, FreeBSD, and Windows. This is the libusb implementation.],
 		[$hidapi_libusb_lib_name],
+		[],
 		[hidapi_libusb_lib_name="$HIDAPI_LIBUSB_LIB_NAME"])
 fi
 m4_undefine([HIDAPI_CONFIGURE_BACKEND_PC])
 
 AC_SUBST([HIDAPI_LIB_NAME])
+AC_SUBST([HIDAPI_PRIVATE_LIBS])
 AC_CONFIG_FILES([pc/hidapi.pc])
 
 AC_SUBST(LTLDFLAGS)

linux/CMakeLists.txt

@@ -9,10 +9,7 @@ target_link_libraries(hidapi_hidraw PUBLIC hidapi_include)
 
 find_package(Threads REQUIRED)
 
-include(FindPkgConfig)
-pkg_check_modules(libudev REQUIRED IMPORTED_TARGET libudev)
-
-target_link_libraries(hidapi_hidraw PRIVATE PkgConfig::libudev Threads::Threads)
+target_link_libraries(hidapi_hidraw PRIVATE Threads::Threads ${CMAKE_DL_LIBS})
 
 set_target_properties(hidapi_hidraw
     PROPERTIES
@@ -28,6 +25,10 @@ add_library(hidapi::hidraw ALIAS hidapi_hidraw)
 # compatibility with raw library link
 add_library(hidapi-hidraw ALIAS hidapi_hidraw)
 
+if(HIDAPI_WITH_TESTS)
+    add_subdirectory(test)
+endif()
+
 if(HIDAPI_INSTALL_TARGETS)
     install(TARGETS hidapi_hidraw EXPORT hidapi
         LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
@@ -40,4 +41,5 @@ hidapi_configure_pc("${PROJECT_ROOT}/pc/hidapi-backend-specific.pc.in"
     OUTPUT_NAME "hidapi-hidraw"
     LIBRARY_NAME "hidapi-hidraw"
     DESCRIPTION "C Library for USB/Bluetooth HID device access from Linux, Mac OS X, FreeBSD, and Windows. This is the hidraw implementation."
+    PRIVATE_LIBS "-ldl"
 )

linux/Makefile-manual

@@ -18,18 +18,17 @@ LDFLAGS  ?= -Wall -g
 
 COBJS     = hid.o ../hidtest/test.o
 OBJS      = $(COBJS)
-LIBS_UDEV = `pkg-config libudev --libs` -lrt
-LIBS      = $(LIBS_UDEV)
-INCLUDES ?= -I../hidapi `pkg-config libusb-1.0 --cflags`
+LIBS_HIDRAW = -ldl
+INCLUDES ?= -I../hidapi
 
 
 # Console Test Program
 hidtest-hidraw: $(COBJS)
-	$(CC) $(LDFLAGS) $^ $(LIBS_UDEV) -o $@
+	$(CC) $(LDFLAGS) $^ $(LIBS_HIDRAW) -o $@
 
 # Shared Libs
 libhidapi-hidraw.so: $(COBJS)
-	$(CC) $(LDFLAGS) $(LIBS_UDEV) -shared -fpic -Wl,-soname,$@.0 $^ -o $@
+	$(CC) $(LDFLAGS) -shared -fpic -Wl,-soname,$@.0 $^ $(LIBS_HIDRAW) -o $@
 
 # Objects
 $(COBJS): %.o: %.c

linux/Makefile.am

@@ -7,4 +7,9 @@ libhidapi_hidraw_la_LIBADD = $(LIBS_HIDRAW)
 hdrdir = $(includedir)/hidapi
 hdr_HEADERS = $(top_srcdir)/hidapi/hidapi.h
 
-EXTRA_DIST = Makefile-manual
+EXTRA_DIST = \
+	Makefile-manual \
+	test/CMakeLists.txt \
+	test/dlopen_interposer.c \
+	test/hidapi_hidraw_loader_test.c \
+	test/incomplete_udev.c