Linting: Integrate into CMake, enable by default.

cmake/RunLint.cmake

@@ -0,0 +1,21 @@
+get_filename_component(LINT_DIR ${LINT_DIR} ABSOLUTE)
+get_filename_component(LINT_PREFIX ${LINT_DIR} PATH)
+file(GLOB_RECURSE LINT_FILES ${LINT_DIR}/*.c ${LINT_DIR}/*.h)
+
+if(LINT_IGNORE_FILE)
+  file(READ ${LINT_IGNORE_FILE} LINT_IGNORED_FILES)
+  string(REPLACE "\n" ";" LINT_IGNORED_FILES ${LINT_IGNORED_FILES})
+  message(STATUS "Ignoring the following files for linting:")
+  foreach(ignore_file ${LINT_IGNORED_FILES})
+    message(STATUS "${ignore_file}")
+    list(REMOVE_ITEM LINT_FILES "${LINT_PREFIX}/${ignore_file}")
+  endforeach()
+endif()
+
+execute_process(
+  COMMAND ${LINT_PRG} ${LINT_FILES}
+  RESULT_VARIABLE res)
+
+if(NOT res EQUAL 0)
+  message(FATAL_ERROR "Linting failed: ${res}.")
+endif()