FindGnuTLS: add target GnuTLS::GnuTLS

Also add a test case for the module.

Help/release/dev/FindGnuTLS-target.rst

@@ -0,0 +1,4 @@
+FindGnuTLS-target
+-----------------
+
+* The :module:`FindGnuTLS` module now provides an imported target.

Modules/FindGnuTLS.cmake

@@ -7,16 +7,25 @@ FindGnuTLS
 
 Find the GNU Transport Layer Security library (gnutls)
 
+IMPORTED Targets
+^^^^^^^^^^^^^^^^
 
+This module defines :prop_tgt:`IMPORTED` target ``GnuTLS::GnuTLS``, if
+gnutls has been found.
 
-Once done this will define
+Result Variables
+^^^^^^^^^^^^^^^^
 
-::
-
-  GNUTLS_FOUND - System has gnutls
-  GNUTLS_INCLUDE_DIR - The gnutls include directory
-  GNUTLS_LIBRARIES - The libraries needed to use gnutls
-  GNUTLS_DEFINITIONS - Compiler switches required for using gnutls
+``GNUTLS_FOUND``
+  System has gnutls
+``GNUTLS_INCLUDE_DIR``
+  The gnutls include directory
+``GNUTLS_LIBRARIES``
+  The libraries needed to use gnutls
+``GNUTLS_DEFINITIONS``
+  Compiler switches required for using gnutls
+``GNUTLS_VERSION``
+  version of gnutls.
 #]=======================================================================]
 
 # Note that this doesn't try to find the gnutls-extra package.
@@ -34,6 +43,8 @@ if (NOT WIN32)
   find_package(PkgConfig QUIET)
   PKG_CHECK_MODULES(PC_GNUTLS QUIET gnutls)
   set(GNUTLS_DEFINITIONS ${PC_GNUTLS_CFLAGS_OTHER})
+  set(GNUTLS_VERSION ${PC_GNUTLS_VERSION})
+  # keep for backward compatibility
   set(GNUTLS_VERSION_STRING ${PC_GNUTLS_VERSION})
 endif ()
 
@@ -59,4 +70,13 @@ FIND_PACKAGE_HANDLE_STANDARD_ARGS(GnuTLS
 if(GNUTLS_FOUND)
   set(GNUTLS_LIBRARIES    ${GNUTLS_LIBRARY})
   set(GNUTLS_INCLUDE_DIRS ${GNUTLS_INCLUDE_DIR})
+
+  if(NOT TARGET GnuTLS::GnuTLS)
+    add_library(GnuTLS::GnuTLS UNKNOWN IMPORTED)
+    set_target_properties(GnuTLS::GnuTLS PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES "${GNUTLS_INCLUDE_DIRS}"
+      INTERFACE_COMPILE_DEFINITIONS "${GNUTLS_DEFINITIONS}"
+      IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+      IMPORTED_LOCATION "${GNUTLS_LIBRARIES}")
+  endif()
 endif()

Tests/CMakeLists.txt

@@ -1394,6 +1394,7 @@ ${CMake_SOURCE_DIR}/Utilities/Release/push.bash --dir dev -- '${CMake_BUILD_NIGH
             GIF
             Git
             GLEW
+            GnuTLS
             GSL
             GTK2
             Iconv

Tests/FindGnuTLS/CMakeLists.txt

@@ -0,0 +1,10 @@
+add_test(NAME FindGnuTLS.Test COMMAND
+  ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
+  --build-and-test
+  "${CMake_SOURCE_DIR}/Tests/FindGnuTLS/Test"
+  "${CMake_BINARY_DIR}/Tests/FindGnuTLS/Test"
+  ${build_generator_args}
+  --build-project TestFindGnuTLS
+  --build-options ${build_options}
+  --test-command ${CMAKE_CTEST_COMMAND} -V -C $<CONFIGURATION>
+  )

Tests/FindGnuTLS/Test/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.4)
+project(TestFindGnuTLS C)
+include(CTest)
+
+find_package(GnuTLS REQUIRED)
+
+add_definitions(-DCMAKE_EXPECTED_GNUTLS_VERSION="${GNUTLS_VERSION}")
+
+add_executable(test_tgt main.c)
+target_link_libraries(test_tgt GnuTLS::GnuTLS)
+add_test(NAME test_tgt COMMAND test_tgt)
+
+add_executable(test_var main.c)
+target_include_directories(test_var PRIVATE ${GNUTLS_INCLUDE_DIRS})
+target_link_libraries(test_var PRIVATE ${GNUTLS_LIBRARIES})
+target_compile_definitions(test_var PRIVATE ${GNUTLS_DEFINITIONS})
+add_test(NAME test_var COMMAND test_var)

Tests/FindGnuTLS/Test/main.c

@@ -0,0 +1,22 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <gnutls/gnutls.h>
+
+int main()
+{
+  // test the linker
+  gnutls_session_t session;
+  if (gnutls_init(&session, GNUTLS_CLIENT)) {
+    gnutls_deinit(session);
+  }
+
+  // check the version
+  char gnutls_version_string[16];
+  snprintf(gnutls_version_string, 16, "%i.%i.%i", GNUTLS_VERSION_MAJOR,
+           GNUTLS_VERSION_MINOR, GNUTLS_VERSION_PATCH);
+  assert(strcmp(gnutls_version_string, CMAKE_EXPECTED_GNUTLS_VERSION) == 0);
+
+  return 0;
+}