CopyIfDifferent

SET(SRC_FILES head1.h head2.h head3.h)
COPY_IF_DIFFERENT( /from_dir /to_dir ${SRC_FILES} IncludeTargets "Includes")
ADD_TARGET(CopyIncludes ALL DEPENDS ${IncludeTargets})

CopyIncludes: $(CopyIncludes_DEPEND_LIBS) \
  Include\head1.h \
  Include\head2.h \
  Include\head3.h

Include\head1.h:
    @echo Building Copying head1.h /to_dir head1.h...
    cmake.exe -E copy_if_different /from_dir/head1.h  /to_dir/head1.h

MACRO(COPY_IF_DIFFERENT FROM_DIR TO_DIR FILES TARGETS TAGS)
# Macro to implement copy_if_different for a list of files
# Arguments -
#   FROM_DIR - this is the source directory
#   TO_DIR   - this is the destination directory
#   FILES    - names of the files to copy
#              TODO: add globing.
#   TARGETS  - List of targets
#   TAGS     - Since only the file name is used
#              to generate rules, pre-pend a user
#              supplied tag to prevent duplicate rule errors.
SET(AddTargets "")
FOREACH(SRC ${FILES})
    GET_FILENAME_COMPONENT(SRCFILE ${SRC} NAME)
    # Command to copy the files to ${STEP1}/src, if changed.
    SET(TARGET  "${TAGS}/${SRCFILE}")
    IF("${FROM_DIR}" STREQUAL "")
        SET(FROM ${SRC})
    ELSE("${FROM_DIR}" STREQUAL "")
        SET(FROM ${FROM_DIR}/${SRC})
    ENDIF("${FROM_DIR}" STREQUAL "")
    IF("${TO_DIR}" STREQUAL "")
        SET(TO ${SRCFILE})
    ELSE("${TO_DIR}" STREQUAL "")
        SET(TO   ${TO_DIR}/${SRCFILE})
    ENDIF("${TO_DIR}" STREQUAL "")
    ADD_CUSTOM_COMMAND(
        OUTPUT  ${TARGET}
        COMMAND ${CMAKE_COMMAND}
        ARGS    -E copy_if_different ${FROM} ${TO}
        COMMENT "Copying ${SRCFILE} ${TO_DIR}"
        )
    SET(AddTargets ${AddTargets} ${TARGET})
ENDFOREACH(SRC ${FILES})
SET(${TARGETS} ${AddTargets})
ENDMACRO(COPY_IF_DIFFERENT FROM_DIR TO_DIR FILES TARGETS TAGS)