OPCUA-3372 Allow configurable URL to download Libsocketcan and verify download HASH

cmake/libsocketcan.cmake

@@ -1,33 +1,86 @@
-FetchContent_Declare(
-  libsocketcan
-  GIT_REPOSITORY https://github.com/linux-can/libsocketcan.git
-  GIT_TAG        v0.0.12
+include(ExternalProject)
+
+set(LIBSOCKETCAN_DEFAULT_URL
+    "https://github.com/linux-can/libsocketcan/archive/refs/tags/v0.0.12.zip"
+)
+
+set(LIBSOCKETCAN_DEFAULT_HASH
+    "SHA256=e634d623990f63b4d67beb5a40daf5db73fb37d1a3b3acf68265b60f3f389fbf"
+)
+
+set(LIBSOCKETCAN_URL "${LIBSOCKETCAN_DEFAULT_URL}"
+    CACHE STRING "URL used to download libsocketcan"
 )
 
-FetchContent_MakeAvailable(libsocketcan)
+set(LIBSOCKETCAN_HASH ""
+    CACHE STRING "Checksum for libsocketcan download. If empty, default URL uses built-in checksum and custom URLs skip verification."
+)
+
+set(_libsocketcan_url_hash)
+
+if(LIBSOCKETCAN_HASH)
+    set(_libsocketcan_url_hash URL_HASH "${LIBSOCKETCAN_HASH}")
+elseif(LIBSOCKETCAN_URL STREQUAL LIBSOCKETCAN_DEFAULT_URL)
+    set(_libsocketcan_url_hash URL_HASH "${LIBSOCKETCAN_DEFAULT_HASH}")
+endif()
+
+find_program(SH_EXE NAMES sh bash REQUIRED)
+find_program(MAKE_EXE NAMES gmake make REQUIRED)
+
+set(LIBSOCKETCAN_PREFIX_DIR  "${CMAKE_BINARY_DIR}/_deps/libsocketcan")
+set(LIBSOCKETCAN_SOURCE_DIR  "${LIBSOCKETCAN_PREFIX_DIR}/src")
+set(LIBSOCKETCAN_BUILD_DIR   "${LIBSOCKETCAN_PREFIX_DIR}/build")
+set(LIBSOCKETCAN_INSTALL_DIR "${LIBSOCKETCAN_PREFIX_DIR}/install")
 
-set(LIBSOCKETCAN_INCLUDE_DIR ${libsocketcan_SOURCE_DIR}/include)
+set(LIBSOCKETCAN_INCLUDE_DIR "${LIBSOCKETCAN_INSTALL_DIR}/include")
+set(LIBSOCKETCAN_LIBRARY     "${LIBSOCKETCAN_INSTALL_DIR}/lib/libsocketcan.a")
 
-set(LIBSOCKETCAN_LIB ${libsocketcan_SOURCE_DIR}/src/.libs/libsocketcan.a)
+# Avoid CMake errors for imported targets whose include directory does not exist
+# yet at configure time.
+file(MAKE_DIRECTORY "${LIBSOCKETCAN_INCLUDE_DIR}")
+file(MAKE_DIRECTORY "${LIBSOCKETCAN_INSTALL_DIR}/lib")
 
-add_custom_command(
-    OUTPUT ${LIBSOCKETCAN_LIB}
-    WORKING_DIRECTORY ${libsocketcan_SOURCE_DIR}
-    COMMAND bash autogen.sh
-    COMMAND bash configure --enable-static --disable-shared CFLAGS=-fPIC CXXFLAGS=-fPIC
-    COMMAND make
-    DEPENDS ${libsocketcan_SOURCE_DIR}
+ExternalProject_Add(libsocketcan_external
+    URL "${LIBSOCKETCAN_URL}"
+    ${_libsocketcan_url_hash}
+
+    DOWNLOAD_EXTRACT_TIMESTAMP FALSE
+
+    SOURCE_DIR "${LIBSOCKETCAN_SOURCE_DIR}"
+    BINARY_DIR "${LIBSOCKETCAN_BUILD_DIR}"
+    INSTALL_DIR "${LIBSOCKETCAN_INSTALL_DIR}"
+
+    CONFIGURE_COMMAND
+        ${CMAKE_COMMAND} -E chdir <SOURCE_DIR>
+            ${SH_EXE} ./autogen.sh
+        COMMAND
+        ${CMAKE_COMMAND} -E env
+            "CFLAGS=-fPIC"
+            "CXXFLAGS=-fPIC"
+            <SOURCE_DIR>/configure
+                --prefix=<INSTALL_DIR>
+                --enable-static
+                --disable-shared
+
+    BUILD_COMMAND
+        ${MAKE_EXE}
+
+    INSTALL_COMMAND
+        ${MAKE_EXE} install
+
+    BUILD_BYPRODUCTS
+        "${LIBSOCKETCAN_LIBRARY}"
+
+    USES_TERMINAL_CONFIGURE TRUE
+    USES_TERMINAL_BUILD TRUE
+    USES_TERMINAL_INSTALL TRUE
 )
 
 add_library(libsocketcan STATIC IMPORTED GLOBAL)
 
 set_target_properties(libsocketcan PROPERTIES
-    IMPORTED_LOCATION ${LIBSOCKETCAN_LIB}
-    INTERFACE_INCLUDE_DIRECTORIES ${LIBSOCKETCAN_INCLUDE_DIR}
-)
-
-add_custom_target(libsocketcan_build ALL
-    DEPENDS ${LIBSOCKETCAN_LIB}
+    IMPORTED_LOCATION "${LIBSOCKETCAN_LIBRARY}"
+    INTERFACE_INCLUDE_DIRECTORIES "${LIBSOCKETCAN_INCLUDE_DIR}"
 )
 
-add_dependencies(libsocketcan libsocketcan_build)
+add_dependencies(libsocketcan libsocketcan_external)

cmake/version.cmake

@@ -3,14 +3,25 @@ execute_process(
     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
     OUTPUT_VARIABLE GIT_COMMIT_HASH
     OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_QUIET
 )
 
 execute_process(
     COMMAND git log -1 --format=%cd
     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
     OUTPUT_VARIABLE GIT_COMMIT_DATE
     OUTPUT_STRIP_TRAILING_WHITESPACE
+    ERROR_QUIET
 )
+
+if(NOT GIT_COMMIT_HASH)
+    set(GIT_COMMIT_HASH "unknown")
+endif()
+
+if(NOT GIT_COMMIT_DATE)
+    set(GIT_COMMIT_DATE "unknown")
+endif()
+
 configure_file (
     "${PROJECT_SOURCE_DIR}/src/include/CanVersion.h.in"
     "${PROJECT_BINARY_DIR}/src/include/CanVersion.h"

docs/DEVELOPMENT.md

@@ -3,10 +3,22 @@
 
 ## Dependencies
 
-- In Linux, you must install the `libsocketcan-devel` package.
+- On Linux, `libsocketcan` is downloaded and built automatically by CMake.
+- If you need to use a mirrored or internal source, configure it with `LIBSOCKETCAN_URL`.
+- If `LIBSOCKETCAN_HASH` is set (for example `SHA256=...`), CMake verifies the download checksum with that value.
+- If `LIBSOCKETCAN_HASH` is not set and `LIBSOCKETCAN_URL` is left at its default value, CMake verifies the download with the built-in default hash.
+- If `LIBSOCKETCAN_HASH` is not set and `LIBSOCKETCAN_URL` is customized, checksum verification is not performed.
 - Other dependencies are resolved automatically after setting the variable `ICS_REPO_DEPS_TOKEN=[value]` to
 your environment (`.env` file). The value is in the group `jcop-opc-ua` configuration of Gitlab CI/CD (gitlab.cern.ch).
 
+Example:
+
+```bash
+cmake -S . -B build \
+  -DLIBSOCKETCAN_URL=https://<your-mirror>/libsocketcan-v0.0.12.zip \
+  -DLIBSOCKETCAN_HASH=SHA256=<sha256>
+```
+
 ## Development environment
 
 - Alma 9

docs/README.md

@@ -30,7 +30,10 @@ The project requires LogIt (part of the Quasar Framework) and it is downloaded a
 Inside CERN, the CMake will also download the Anagate API. If not, please modify the address to
 download the API directly from anagate.de
 
-For Linux, the user must install `libsocketcan` and the matching devel package.
+For Linux, `libsocketcan` is fetched and built automatically during CMake configuration. You can override
+the download source with `LIBSOCKETCAN_URL`. If `LIBSOCKETCAN_HASH` is provided, CMake verifies the
+download checksum with that value. If no hash is provided, the default URL is still verified with its
+built-in hash, while custom URLs are downloaded without checksum verification.
 
 Optionally, the user must install pybind11 to generate the Python bindings.