Option to check headers at compile time. (aws#175)

This is adapted from the header-checker in aws-c-common, but with separate passes for c++ 11,14,17,20.

Also, sync submodules back to latest release

Author: graebm

CMakeLists.txt

@@ -2,6 +2,8 @@ cmake_minimum_required(VERSION 3.1)
 project(aws-crt-cpp CXX C)
 option(BUILD_DEPS "Builds aws common runtime dependencies as part of build, only do this if you don't want to control your dependency chain." OFF)
 
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+include(AwsCheckHeadersCxx)
 include(CTest)
 
 if (DEFINED CMAKE_PREFIX_PATH)
@@ -119,14 +121,20 @@ file(GLOB AWS_CRT_EXTERNAL_HEADERS
         "include/aws/crt/external/*.h"
 )
 
-file(GLOB AWS_CRT_CPP_HEADERS
+file(GLOB AWS_CRT_PUBLIC_HEADERS
         ${AWS_CRT_HEADERS}
         ${AWS_CRT_AUTH_HEADERS}
         ${AWS_CRT_CRYPTO_HEADERS}
         ${AWS_CRT_IO_HEADERS}
         ${AWS_CRT_IOT_HEADERS}
         ${AWS_CRT_MQTT_HEADERS}
         ${AWS_CRT_HTTP_HEADERS}
+)
+
+aws_check_headers_cxx(${PROJECT_NAME} ${AWS_CRT_PUBLIC_HEADERS})
+
+file(GLOB AWS_CRT_CPP_HEADERS
+        ${AWS_CRT_PUBLIC_HEADERS}
         ${AWS_CRT_EXTERNAL_HEADERS}
 )
 
@@ -195,7 +203,7 @@ if (WIN32)
     endif ()
 endif()
 
-add_library(${PROJECT_NAME} ${AWS_CRT_CPP_SRC})
+add_library(${PROJECT_NAME} ${AWS_CRT_CPP_HEADERS} ${AWS_CRT_CPP_SRC})
 
 target_compile_definitions(${PROJECT_NAME} PRIVATE -DCJSON_HIDE_SYMBOLS)
 
@@ -247,7 +255,6 @@ install(FILES ${AWS_CRT_IO_HEADERS} DESTINATION "include/aws/crt/io" COMPONENT D
 install(FILES ${AWS_CRT_IOT_HEADERS} DESTINATION "include/aws/iot" COMPONENT Development)
 install(FILES ${AWS_CRT_MQTT_HEADERS} DESTINATION "include/aws/crt/mqtt" COMPONENT Development)
 install(FILES ${AWS_CRT_HTTP_HEADERS} DESTINATION "include/aws/crt/http" COMPONENT Development)
-install(FILES ${AWS_CRT_EXTERNAL_HEADERS} DESTINATION "include/aws/crt/external" COMPONENT Development)
 
 install(
         TARGETS ${PROJECT_NAME}

aws-common-runtime/aws-c-auth

@@ -2,7 +2,7 @@
     "name": "aws-crt-cpp",
     "!cmake_args": [
         "-DBUILD_DEPS=ON",
-        "-DPERFORM_HEADER_CHECK=OFF",
+        "-DPERFORM_HEADER_CHECK_CXX=ON",
         "-DS2N_NO_PQ_ASM=ON"
     ],
     "targets": {

aws-common-runtime/aws-c-cal

@@ -0,0 +1,65 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0.
+
+# This cmake logic verifies that each of our headers is complete, in that it
+# includes any necessary dependencies, and builds with each supported c++ standard.
+#
+# To do so, we generate a single-line C or C++ source file that includes each
+# header, and link all of these stub source files into a test executable.
+
+option(PERFORM_HEADER_CHECK_CXX "Performs compile-time checks that each header can be included independently.")
+
+# Call as: aws_check_headers_cxx(${target} HEADERS TO CHECK LIST)
+function(aws_check_headers_cxx target)
+    # Check headers against each supported CXX_STANDARD
+    if (PERFORM_HEADER_CHECK_CXX)
+        aws_check_headers_cxx_internal(${target} 11 ${ARGN})
+        aws_check_headers_cxx_internal(${target} 14 ${ARGN})
+
+        if (NOT CMAKE_VERSION VERSION_LESS "3.8")
+            aws_check_headers_cxx_internal(${target} 17 ${ARGN})
+
+            if (NOT CMAKE_VERSION VERSION_LESS "3.12")
+                aws_check_headers_cxx_internal(${target} 20 ${ARGN})
+            endif ()
+        endif ()
+    endif ()
+endfunction()
+
+function(aws_check_headers_cxx_internal target std)
+    set(HEADER_CHECKER_ROOT "${CMAKE_CURRENT_BINARY_DIR}/header-checker-cxx-${std}")
+
+    # Write stub main file
+    set(HEADER_CHECKER_MAIN "${HEADER_CHECKER_ROOT}/stub.cpp")
+    file(WRITE ${HEADER_CHECKER_MAIN} "
+        int main(int argc, char **argv) {
+            (void)argc;
+            (void)argv;
+
+            return 0;
+        }")
+
+    set(HEADER_CHECKER_LIB ${target}-header-check-cxx-${std})
+    add_executable(${HEADER_CHECKER_LIB} ${HEADER_CHECKER_MAIN})
+    target_link_libraries(${HEADER_CHECKER_LIB} ${target})
+    target_compile_definitions(${HEADER_CHECKER_LIB} PRIVATE AWS_UNSTABLE_TESTING_API=1 AWS_HEADER_CHECKER=1)
+
+    set_target_properties(${HEADER_CHECKER_LIB} PROPERTIES
+        LINKER_LANGUAGE CXX
+        CXX_STANDARD ${std}
+        CXX_STANDARD_REQUIRED OFF
+    )
+
+    foreach(header IN LISTS ARGN)
+        if (NOT ${header} MATCHES "\\.inl$")
+            file(RELATIVE_PATH rel_header ${CMAKE_HOME_DIRECTORY} ${header})
+            file(RELATIVE_PATH include_path "${CMAKE_HOME_DIRECTORY}/include" ${header})
+            set(stub_dir "${HEADER_CHECKER_ROOT}/${rel_header}")
+            file(MAKE_DIRECTORY "${stub_dir}")
+            # include file twice to ensure header guards are present
+            file(WRITE "${stub_dir}/check.cpp" "#include <${include_path}>\n#include <${include_path}>\n")
+
+            target_sources(${HEADER_CHECKER_LIB} PUBLIC "${stub_dir}/check.cpp")
+        endif()
+    endforeach(header)
+endfunction()