cmake: Add support for test build

components/libsodium/CMakeLists.txt

@@ -166,4 +166,10 @@ if(GCC_NOT_5_2_0)
         PROPERTIES COMPILE_FLAGS
         -Wno-implicit-fallthrough
         )
-endif()
+endif()
+
+set_source_files_properties(
+    ${SRC}/randombytes/randombytes.c
+    PROPERTIES COMPILE_FLAGS
+    -DRANDOMBYTES_DEFAULT_IMPLEMENTATION
+)

components/libsodium/test/CMakeLists.txt

@@ -0,0 +1,40 @@
+if(TESTS_ALL EQUAL 1)
+    message("not linking libsodium tests, use '-T libsodium' to test it")
+else()
+    get_filename_component(LS_TESTDIR "${CMAKE_CURRENT_LIST_DIR}/../libsodium/test/default" ABSOLUTE)
+
+    set(COMPONENT_ADD_INCLUDEDIRS "." "${LS_TESTDIR}/../quirks")
+
+    set(COMPONENT_REQUIRES unity libsodium)
+
+    set(TEST_CASES "chacha20;aead_chacha20poly1305;box;box2;ed25519_convert;sign;hash")
+
+    foreach(test_case ${TEST_CASES})
+        file(GLOB test_case_file "${LS_TESTDIR}/${test_case}.c")
+        list(APPEND TEST_CASES_FILES ${test_case_file})
+    endforeach()
+
+    set(COMPONENT_SRCS "${TEST_CASES_FILES};test_sodium.c")
+
+    register_component()
+
+    # The libsodium test suite is designed to be run each test case as an executable on a desktop computer and uses
+    # filesytem to write & then compare contents of each file.
+    #
+    # For now, use their "BROWSER_TEST" mode with these hacks so that
+    # multiple test cases can be combined into one ELF file.
+    #
+    # Run each test case from test_sodium.c as CASENAME_xmain().
+    foreach(test_case_file ${TEST_CASES_FILES})
+        get_filename_component(test_case ${test_case_file} NAME_WE)
+        set_source_files_properties(${test_case_file}
+                                    PROPERTIES COMPILE_FLAGS
+                                    # This would generate 'warning "main" redefined' warnings at runtime, which are
+                                    # silenced here. Only other solution involves patching libsodium's cmptest.h.
+                                    "-Dxmain=${test_case}_xmain -Dmain=${test_case}_main -Wp,-w")
+    endforeach()
+
+    # this seems odd, but it prevents the libsodium test harness from
+    # trying to write to a file!
+    add_definitions(-DBROWSER_TESTS)
+endif()