Allow CMake to generate query_config.c

This one was trickier for two reasons:

1. It's used from another directory, see
https://gitlab.kitware.com/cmake/community/-/wikis/FAQ#how-can-i-add-a-dependency-to-a-source-file-which-is-generated-in-a-subdirectory

2. The C file being generated after CMake is run means CMake can't
automatically scan for included headers and do its usual magic, so we
need to declare the dependency and more importantly the include path.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>

programs/ssl/CMakeLists.txt

@@ -18,17 +18,32 @@ set(executables
     ssl_server2
 )
 
+# Inform CMake the the following file will be generated as part of the build
+# process, so it doesn't complain that it doesn't exist yet. Starting from
+# CMake 3.20, this will no longer be necessary as CMake will automatically
+# propagate this information accross the tree, for now it's only visible
+# inside the same directory, so we need to propagate manually.
+set_source_files_properties(
+    ${CMAKE_CURRENT_BINARY_DIR}/../test/query_config.c
+    PROPERTIES GENERATED TRUE)
+
 foreach(exe IN LISTS executables)
     set(extra_sources "")
     if(exe STREQUAL "ssl_client2" OR exe STREQUAL "ssl_server2")
         list(APPEND extra_sources
             ssl_test_lib.c
-            ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.c)
+            ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.h
+            ${CMAKE_CURRENT_BINARY_DIR}/../test/query_config.c)
     endif()
     add_executable(${exe} ${exe}.c $<TARGET_OBJECTS:mbedtls_test>
         ${extra_sources})
     target_link_libraries(${exe} ${libs})
     target_include_directories(${exe} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../tests/include)
+    if(exe STREQUAL "ssl_client2" OR exe STREQUAL "ssl_server2")
+        add_dependencies(${exe} generate_query_config_c)
+        target_include_directories(${exe}
+            PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../test)
+    endif()
 endforeach()
 
 if(THREADS_FOUND)

programs/test/CMakeLists.txt

@@ -27,15 +27,40 @@ if(TEST_CPP)
     target_link_libraries(cpp_dummy_build ${mbedcrypto_target})
 endif()
 
+find_package(Perl REQUIRED)
+
+add_custom_command(
+    OUTPUT
+        ${CMAKE_CURRENT_BINARY_DIR}/query_config.c
+    COMMAND
+        ${PERL}
+            ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_query_config.pl
+            ${CMAKE_CURRENT_SOURCE_DIR}/../../include/mbedtls/mbedtls_config.h
+            ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/data_files/query_config.fmt
+            ${CMAKE_CURRENT_BINARY_DIR}/query_config.c
+    DEPENDS
+        ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_query_config.pl
+        ${CMAKE_CURRENT_SOURCE_DIR}/../../include/mbedtls/mbedtls_config.h
+        ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/data_files/query_config.fmt
+)
+# this file will also be used in anoter directory, so create a target, see
+# https://gitlab.kitware.com/cmake/community/-/wikis/FAQ#how-can-i-add-a-dependency-to-a-source-file-which-is-generated-in-a-subdirectory
+add_custom_target(generate_query_config_c
+    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/query_config.c)
+
 foreach(exe IN LISTS executables_libs executables_mbedcrypto)
     set(extra_sources "")
     if(exe STREQUAL "query_compile_time_config")
         list(APPEND extra_sources
-            ${CMAKE_CURRENT_SOURCE_DIR}/query_config.c)
+            ${CMAKE_CURRENT_SOURCE_DIR}/query_config.h
+            ${CMAKE_CURRENT_BINARY_DIR}/query_config.c)
     endif()
     add_executable(${exe} ${exe}.c $<TARGET_OBJECTS:mbedtls_test>
         ${extra_sources})
     target_include_directories(${exe} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../tests/include)
+    if(exe STREQUAL "query_compile_time_config")
+        target_include_directories(${exe} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+    endif()
 
     # This emulates "if ( ... IN_LIST ... )" which becomes available in CMake 3.3
     list(FIND executables_libs ${exe} exe_index)