#.rst:
# ECMGenerateHeaders
# ------------------
#
# Generate C/C++ CamelCase forwarding headers.
#
# ::
#
# ecm_generate_headers(<camelcase_forwarding_headers_var>
# HEADER_NAMES <CamelCaseName> [<CamelCaseName> [...]]
# [ORIGINAL <CAMELCASE|LOWERCASE>]
# [OUTPUT_DIR <output_dir>]
# [PREFIX <prefix>]
# [REQUIRED_HEADERS <variable>]
# [RELATIVE <relative_path>])
#
# For each CamelCase header name passed to HEADER_NAMES, a file of that name
# will be generated that will include a version with ``.h`` appended.
# For example, the generated header ``ClassA`` will include ``classa.h`` (or
# ``ClassA.h``, see ORIGINAL).
# The file locations of these generated headers will be stored in
# <camelcase_forwarding_headers_var>.
#
# ORIGINAL specifies how the name of the original header is written: lowercased
# or also camelcased. The default is LOWERCASE. Since 1.8.0.
#
# PREFIX places the generated headers in subdirectories. This should be a
# CamelCase name like ``KParts``, which will cause the CamelCase forwarding
# headers to be placed in the ``KParts`` directory (e.g. ``KParts/Part``). It
# will also, for the convenience of code in the source distribution, generate
# forwarding headers based on the original names (e.g. ``kparts/part.h``). This
# allows includes like ``"#include <kparts/part.h>"`` to be used before
# installation, as long as the include_directories are set appropriately.
#
# OUTPUT_DIR specifies where the files will be generated; this should be within
# the build directory. By default, ``${CMAKE_CURRENT_BINARY_DIR}`` will be used.
# This option can be used to avoid file conflicts.
#
# REQUIRED_HEADERS specifies an output variable name where all the required
# headers will be appended so that they can be installed together with the
# generated ones. This is mostly intended as a convenience so that adding a new
# header to a project only requires specifying the CamelCase variant in the
# CMakeLists.txt file; the original variant will then be added to this
# variable.
#
# The RELATIVE argument indicates where the original headers can be found
# relative to CMAKE_CURRENT_SOURCE_DIR. It does not affect the generated
# CamelCase forwarding files, but ecm_generate_headers() uses it when checking
# that the original header exists, and to generate originally named forwarding
# headers when PREFIX is set.
#
# To allow other parts of the source distribution (eg: tests) to use the
# generated headers before installation, it may be desirable to set the
# INCLUDE_DIRECTORIES property for the library target to output_dir. For
# example, if OUTPUT_DIR is CMAKE_CURRENT_BINARY_DIR (the default), you could do
#
# .. code-block:: cmake
#
# target_include_directories(MyLib PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>")
#
# Example usage (without PREFIX):
#
# .. code-block:: cmake
#
# ecm_generate_headers(
# MyLib_FORWARDING_HEADERS
# HEADERS
# MLFoo
# MLBar
# # etc
# REQUIRED_HEADERS MyLib_HEADERS
# )
# install(FILES ${MyLib_FORWARDING_HEADERS} ${MyLib_HEADERS}
# DESTINATION ${CMAKE_INSTALL_PREFIX}/include
# COMPONENT Devel)
#
# Example usage (with PREFIX):
#
# .. code-block:: cmake
#
# ecm_generate_headers(
# MyLib_FORWARDING_HEADERS
# HEADERS
# Foo
# Bar
# # etc
# PREFIX MyLib
# REQUIRED_HEADERS MyLib_HEADERS
# )
# install(FILES ${MyLib_FORWARDING_HEADERS}
# DESTINATION ${CMAKE_INSTALL_PREFIX}/include/MyLib
# COMPONENT Devel)
# install(FILES ${MyLib_HEADERS}
# DESTINATION ${CMAKE_INSTALL_PREFIX}/include/mylib
# COMPONENT Devel)
#
# Since pre-1.0.0.
#=============================================================================
# Copyright 2013 Aleix Pol Gonzalez <aleixpol@blue-systems.com>
# Copyright 2014 Alex Merry <alex.merry@kdemail.net>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file COPYING-CMAKE-SCRIPTS for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of extra-cmake-modules, substitute the full
# License text for the above reference.)
include(CMakeParseArguments)
function(ECM_GENERATE_HEADERS camelcase_forwarding_headers_var)
set(options)
set(oneValueArgs ORIGINAL OUTPUT_DIR PREFIX REQUIRED_HEADERS RELATIVE)
set(multiValueArgs HEADER_NAMES)
cmake_parse_arguments(EGH "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
if (EGH_UNPARSED_ARGUMENTS)
message(FATAL_ERROR "Unexpected arguments to ECM_GENERATE_HEADERS: ${EGH_UNPARSED_ARGUMENTS}")
endif()
if(NOT EGH_HEADER_NAMES)
message(FATAL_ERROR "Missing header_names argument to ECM_GENERATE_HEADERS")
endif()
if(NOT EGH_ORIGINAL)
# default
set(EGH_ORIGINAL "LOWERCASE")
endif()
if(NOT EGH_ORIGINAL STREQUAL "LOWERCASE" AND NOT EGH_ORIGINAL STREQUAL "CAMELCASE")
message(FATAL_ERROR "Unexpected value for original argument to ECM_GENERATE_HEADERS: ${EGH_ORIGINAL}")
endif()
if(NOT EGH_OUTPUT_DIR)
set(EGH_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}")
endif()
# Make sure EGH_RELATIVE is /-terminated when it's not empty
if (EGH_RELATIVE AND NOT "${EGH_RELATIVE}" MATCHES "^.*/$")
set(EGH_RELATIVE "${EGH_RELATIVE}/")
endif()
if (EGH_PREFIX)
if (NOT "${EGH_PREFIX}" MATCHES "^.*/$")
set(EGH_PREFIX "${EGH_PREFIX}/")
endif()
if (EGH_ORIGINAL STREQUAL "CAMELCASE")
set(originalprefix "${EGH_PREFIX}")
else()
string(TOLOWER "${EGH_PREFIX}" originalprefix)
endif()
endif()
foreach(_CLASSNAME ${EGH_HEADER_NAMES})
if (EGH_ORIGINAL STREQUAL "CAMELCASE")
set(originalclassname "${_CLASSNAME}")
else()
string(TOLOWER "${_CLASSNAME}" originalclassname)
endif()
set(FANCY_HEADER_FILE "${EGH_OUTPUT_DIR}/${EGH_PREFIX}${_CLASSNAME}")
set(_actualheader "${CMAKE_CURRENT_SOURCE_DIR}/${EGH_RELATIVE}${originalclassname}.h")
if (NOT EXISTS ${_actualheader})
message(FATAL_ERROR "Could not find \"${_actualheader}\"")
endif()
if (NOT EXISTS ${FANCY_HEADER_FILE})
file(WRITE ${FANCY_HEADER_FILE} "#include \"${originalprefix}${originalclassname}.h\"\n")
endif()
list(APPEND ${camelcase_forwarding_headers_var} "${FANCY_HEADER_FILE}")
if (EGH_REQUIRED_HEADERS)
list(APPEND ${EGH_REQUIRED_HEADERS} "${_actualheader}")
endif()
if (EGH_PREFIX)
# Local forwarding header, for namespaced headers, e.g. kparts/part.h
set(REGULAR_HEADER_NAME ${EGH_OUTPUT_DIR}/${originalprefix}${originalclassname}.h)
if (NOT EXISTS ${REGULAR_HEADER_NAME})
file(WRITE ${REGULAR_HEADER_NAME} "#include \"${_actualheader}\"\n")
endif()
endif()
endforeach()
set(${camelcase_forwarding_headers_var} ${${camelcase_forwarding_headers_var}} PARENT_SCOPE)
if (NOT EGH_REQUIRED_HEADERS STREQUAL "")
set(${EGH_REQUIRED_HEADERS} ${${EGH_REQUIRED_HEADERS}} PARENT_SCOPE)
endif ()
endfunction()