Added Generation of Missing Header

wpiutil/CMakeLists.txt

@@ -254,3 +254,253 @@ if(WITH_TESTS)
         target_compile_options(wpiutil_test PRIVATE /utf-8)
     endif()
 endif()
+
+# Copied from https://github.com/foonathan/memory/blob/016c9fbd61b57ed2058551dcf225c15a0e716cce/cmake/get_container_node_sizes.cmake#L7
+# We need to capture this outside of a function as
+# CMAKE_CURRENT_LIST_DIR reflects the current CMakeLists.txt file when
+# a function is executed, but reflects this directory while this file
+# is being processed.
+set(_THIS_MODULE_DIR ${CMAKE_CURRENT_LIST_DIR})
+
+if(NOT DEFINED _DEBUG_GET_CONTAINER_NODE_SIZES)
+    set(_DEBUG_GET_CONTAINER_NODE_SIZES OFF)
+endif()
+
+function(_gcns_debug_message)
+    if(_DEBUG_GET_CONTAINER_NODE_SIZES)
+        message("${ARGV}")
+    endif()
+endfunction()
+
+# This function will return the alignment of the C++ type specified in
+# 'type', the result will be in 'result_var'.
+function(get_alignof_type type result_var)
+    # We expect this compilation to fail - the purpose of this is to
+    # generate a compile error on a generated tyoe
+    # "align_of<type,value>" that is the alignment of the specified
+    # type.
+    #
+    # See the contents of get_align_of.cpp for more details.
+    try_compile(
+        align_result
+        ${CMAKE_CURRENT_BINARY_DIR}
+        ${_THIS_MODULE_DIR}/src/main/native/thirdparty/memory/src/get_align_of.cpp
+        COMPILE_DEFINITIONS "-DTEST_TYPE=${type}"
+        OUTPUT_VARIABLE align_output
+        CXX_STANDARD 11
+        CXX_STANDARD_REQUIRED TRUE
+    )
+
+    # Look for the align_of<..., ##> in the compiler error output
+    string(REGEX MATCH "align_of<.*,[ ]*([0-9]+)[ul ]*>" align_of_matched ${align_output})
+
+    if(align_of_matched)
+        set(${result_var} ${CMAKE_MATCH_1} PARENT_SCOPE)
+    else()
+        message(
+            FATAL_ERROR
+            "Unable to determine alignment of C++ type ${type} - no error text matching align_of<..., ##> in compiler output |${align_output}|"
+        )
+    endif()
+endfunction()
+
+# This function will return a list of C++ types with unique alignment
+# values, covering all possible alignments supported by the currently
+# configured C++ compiler.
+#
+# The variable named in 'result_types' will contain a list of types,
+# and 'result_alignments' will contain a parallel list of the same
+# size that is the aligment of each of the matching types.
+function(unique_aligned_types result_types result_alignments)
+    # These two lists will contain a set of types with unique alignments.
+    set(alignments)
+    set(types)
+
+    set(all_types
+        char
+        bool
+        short
+        int
+        long
+        LONG_LONG
+        float
+        double
+        LONG_DOUBLE
+    )
+    foreach(type IN LISTS all_types)
+        get_alignof_type("${type}" alignment)
+        _gcns_debug_message("Alignment of '${type}' is '${alignment}'")
+
+        if(NOT ${alignment} IN_LIST alignments)
+            list(APPEND alignments ${alignment})
+            list(APPEND types ${type})
+        endif()
+    endforeach()
+
+    set(${result_types} ${types} PARENT_SCOPE)
+    set(${result_alignments} ${alignments} PARENT_SCOPE)
+endfunction()
+
+# This function will return node sizes for the requested container
+# when created with the specified set of types.
+#
+# 'container' must be one of the container types supported by
+# get_node_size.cpp (see that file for details)
+#
+# 'types' is a list of C++ types to hold in the container to measure
+# the node size
+#
+# 'align_result_var' will contain the list of alignments of contained
+# types used.
+#
+# 'nodesize_result_var' will contain the list of node sizes, one entry
+# for each alignment/type
+function(get_node_sizes_of container types align_result_var nodesize_result_var)
+    set(alignments)
+    set(node_sizes)
+
+    foreach(type IN LISTS types)
+        # We expect this to fail - the purpose of this is to generate
+        # a compile error on a generated type
+        # "node_size_of<type_size,node_size,is_node_size>" that is the
+        # alignment of the specified type.
+        try_compile(
+            nodesize_result
+            ${CMAKE_CURRENT_BINARY_DIR}
+            ${_THIS_MODULE_DIR}/src/main/native/thirdparty/memory/src/get_node_size.cpp
+            COMPILE_DEFINITIONS "-D${container}=1" "-DTEST_TYPE=${type}"
+            OUTPUT_VARIABLE nodesize_output
+            CXX_STANDARD 11
+            CXX_STANDARD_REQUIRED TRUE
+        )
+
+        if(NOT nodesize_output)
+            message(
+                FATAL_ERROR
+                "Unable to determine node size of C++ container ${container} holding type ${type} - no error text matching node_size_of<##, ##, true> in compiler output |${nodesize_output}|"
+            )
+        endif()
+
+        # Find the instance of node_size_of<##, ##, true> in the
+        # compiler error output - the first number is the alignment,
+        # and the second is the node size.
+        string(
+            REGEX MATCH
+            "node_size_of<[ ]*([0-9]+)[ul ]*,[ ]*([0-9]+)[ul ]*,[ ]*true[ ]*>"
+            node_size_of_match
+            ${nodesize_output}
+        )
+
+        if(node_size_of_match)
+            # Extract the alignment and node size
+            if(NOT ${CMAKE_MATCH_1} IN_LIST alignments)
+                list(APPEND alignments ${CMAKE_MATCH_1})
+                list(APPEND node_sizes ${CMAKE_MATCH_2})
+            endif()
+        else()
+            message(
+                FATAL_ERROR
+                "Unable to determine node size of C++ container ${container} holding type ${type} - no error text matching node_size_of<##, ##, true> in compiler output |${nodesize_output}|"
+            )
+        endif()
+    endforeach()
+
+    # Return output to caller
+    set(${align_result_var} ${alignments} PARENT_SCOPE)
+    set(${nodesize_result_var} ${node_sizes} PARENT_SCOPE)
+endfunction()
+
+# This will write the container node sizes to an output header file
+# that can be used to calculate the node size of a container holding
+# the specified type.
+function(get_container_node_sizes outfile)
+    message(STATUS "Getting container node sizes")
+
+    # Build up the file contents in the variable NODE_SIZE_CONTENTS,
+    # as requested in container_node_sizes_impl.hpp.in
+    set(NODE_SIZE_CONTENTS "")
+
+    # Get the set of uniquely aligned types to work with
+    unique_aligned_types(types alignments)
+    _gcns_debug_message("=> alignments |${alignments}| types |${types}|")
+
+    set(container_types
+        forward_list
+        list
+        set
+        multiset
+        unordered_set
+        unordered_multiset
+        map
+        multimap
+        unordered_map
+        unordered_multimap
+        shared_ptr_stateless
+        shared_ptr_stateful
+    )
+
+    foreach(container IN LISTS container_types)
+        string(TOUPPER "${container}_container" container_macro_name)
+        get_node_sizes_of("${container_macro_name}" "${types}" alignments node_sizes)
+        _gcns_debug_message("node size of |${container_macro_name}| holding types |${types}| : alignments |${alignments}| node sizes |${node_sizes}|")
+
+        # Generate the contents for this container type
+        string(
+            APPEND
+            NODE_SIZE_CONTENTS
+            "\
+
+namespace detail
+{
+    template <std::size_t Alignment>
+    struct ${container}_node_size;
+"
+        )
+
+        list(LENGTH alignments n_alignments)
+        math(EXPR last_alignment "${n_alignments}-1")
+        foreach(index RANGE ${last_alignment})
+            list(GET alignments ${index} alignment)
+            list(GET node_sizes ${index} node_size)
+
+            # Generate content for this alignment/node size in this container
+            string(
+                APPEND
+                NODE_SIZE_CONTENTS
+                "\
+
+    template <>
+    struct ${container}_node_size<${alignment}>
+    : std::integral_constant<std::size_t, ${node_size}>
+    {};
+"
+            )
+        endforeach()
+
+        # End contents for this container type
+        string(
+            APPEND
+            NODE_SIZE_CONTENTS
+            "\
+} // namespace detail
+
+template <typename T>
+struct ${container}_node_size
+: std::integral_constant<std::size_t,
+       detail::${container}_node_size<alignof(T)>::value + sizeof(T)>
+{};
+"
+        )
+    endforeach()
+
+    # Finally, write the file.  As a reminder, configure_file() will
+    # substitute in any CMake variables wrapped in @VAR@ in the inpout
+    # file and write them to the output file; and will only rewrite
+    # the file and update its timestamp if the contents have changed.
+    # The only variable that will be substituted is NODE_SIZE_CONTENTS
+    configure_file("${_THIS_MODULE_DIR}/container_node_sizes_impl.hpp.in" ${outfile})
+endfunction()
+
+if(NOT EXISTS ${CMAKE_CURRENT_BINARY_DIR}/container_node_sizes_impl.hpp)
+    get_container_node_sizes(${CMAKE_CURRENT_BINARY_DIR}/container_node_sizes_impl.hpp)
+endif()

wpiutil/container_node_sizes_impl.hpp.in

@@ -0,0 +1,4 @@
+// The following section was autogenerated by get_container_node_sizes.cmake
+//=== BEGIN AUTOGENERATED SECTION ===//
+@NODE_SIZE_CONTENTS@
+//=== END AUTOGENERATED SECTION ===//