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Diffstat (limited to 'src/boost/libs/hana/cmake/TestHeaders.cmake')
| -rw-r--r-- | src/boost/libs/hana/cmake/TestHeaders.cmake | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/boost/libs/hana/cmake/TestHeaders.cmake b/src/boost/libs/hana/cmake/TestHeaders.cmake new file mode 100644 index 000000000..663c9f4e8 --- /dev/null +++ b/src/boost/libs/hana/cmake/TestHeaders.cmake @@ -0,0 +1,128 @@ +# Copyright Louis Dionne 2013-2017 +# Distributed under the Boost Software License, Version 1.0. +# (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) +# +# +# This CMake module provides a function generating a unit test to make sure +# that every public header can be included on its own. +# +# When a C++ library or application has many header files, it can happen that +# a header does not include all the other headers it depends on. When this is +# the case, it can happen that including that header file on its own will +# break the compilation. This CMake module generates a dummy executable +# comprised of many .cpp files, each of which includes a header file that +# is part of the public API. In other words, the executable is comprised +# of .cpp files of the form: +# +# #include <the/public/header.hpp> +# +# and then exactly one `main` function. If this succeeds to compile, it means +# that the header can be included on its own, which is what clients expect. +# Otherwise, you have a problem. Since writing these dumb unit tests by hand +# is tedious and repetitive, you can use this CMake module to automate this +# task. + +# add_header_test(<target> [EXCLUDE_FROM_ALL] [EXCLUDE excludes...] HEADERS headers...) +# +# Generates header-inclusion unit tests for all the specified headers. +# +# This function creates a target which builds a dummy executable including +# each specified header file individually. If this target builds successfully, +# it means that all the specified header files can be included individually. +# +# Parameters +# ---------- +# <target>: +# The name of the target to generate. +# +# HEADERS headers: +# A list of header files to generate the inclusion tests for. All headers +# in this list must be represented as relative paths from the root of the +# include directory added to the compiler's header search path. In other +# words, it should be possible to include all headers in this list as +# +# #include <${header}> +# +# For example, for a library with the following structure: +# +# project/ +# doc/ +# test/ +# ... +# include/ +# boost/ +# hana.hpp +# hana/ +# transform.hpp +# tuple.hpp +# pair.hpp +# ... +# +# When building the unit tests for that library, we'll add `-I project/include' +# to the compiler's arguments. The list of public headers should therefore contain +# +# boost/hana.hpp +# boost/hana/transform.hpp +# boost/hana/tuple.hpp +# boost/hana/pair.hpp +# ... +# +# Usually, all the 'public' header files of a library should be tested for +# standalone inclusion. A header is considered 'public' if a client should +# be able to include that header on its own. +# +# [EXCLUDE excludes]: +# An optional list of headers or regexes for which no unit test should be +# generated. Basically, any header in the list specified by the `HEADERS` +# argument that matches anything in `EXCLUDE` will be skipped. +# +# [EXCLUDE_FROM_ALL]: +# If provided, the generated target is excluded from the 'all' target. +# +function(add_header_test target) + cmake_parse_arguments(ARGS "EXCLUDE_FROM_ALL" # options + "" # 1 value args + "HEADERS;EXCLUDE" # multivalued args + ${ARGN}) + if (NOT ARGS_HEADERS) + message(FATAL_ERROR "The `HEADERS` argument must be provided.") + endif() + + if (ARGS_EXCLUDE_FROM_ALL) + set(ARGS_EXCLUDE_FROM_ALL "EXCLUDE_FROM_ALL") + else() + set(ARGS_EXCLUDE_FROM_ALL "") + endif() + + foreach(header ${ARGS_HEADERS}) + set(skip FALSE) + foreach(exclude ${ARGS_EXCLUDE}) + if (${header} MATCHES ${exclude}) + set(skip TRUE) + break() + endif() + endforeach() + if (skip) + continue() + endif() + + get_filename_component(filename "${header}" NAME_WE) + get_filename_component(directory "${header}" DIRECTORY) + + set(source "${CMAKE_CURRENT_BINARY_DIR}/headers/${directory}/${filename}.cpp") + if (NOT EXISTS "${source}") + file(WRITE "${source}" "#include <${header}>") + endif() + list(APPEND sources "${source}") + endforeach() + + set(standalone_main "${CMAKE_CURRENT_BINARY_DIR}/headers/_standalone_main.cpp") + if (NOT EXISTS "${standalone_main}") + file(WRITE "${standalone_main}" "int main() { }") + endif() + add_executable(${target} + ${ARGS_EXCLUDE_FROM_ALL} + ${sources} + "${CMAKE_CURRENT_BINARY_DIR}/headers/_standalone_main.cpp" + ) +endfunction() |