qt5base-lts/cmake/QtWasmHelpers.cmake
Morten Sørvig be44827240 wasm: add support for building Qt as shared libraries
This implements the build system bits required to build Qt
as as separate wasm modules a.k.a Emscripten side modules.

Enable by configuring with the "-shared" flag.

This is the first step towards shared library support and gets
us as far as being able to load QtCore and instantiate a
QCoreApplication.

Task-number: QTBUG-63925
Change-Id: Ib8f07f80fb5b13c8dbba65c7db735dc557b70d0e
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
2022-08-30 22:11:01 +10:00

110 lines
4.6 KiB
CMake

# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: BSD-3-Clause
# WARNING must keep in sync with wasm-emscripten/qmake.conf!
function (qt_internal_setup_wasm_target_properties wasmTarget)
target_link_options("${wasmTarget}" INTERFACE
"SHELL:-s MAX_WEBGL_VERSION=2"
"SHELL:-s FETCH=1"
"SHELL:-s WASM_BIGINT=1")
target_link_libraries("${wasmTarget}" INTERFACE embind)
# Enable MODULARIZE and set EXPORT_NAME, which makes it possible to
# create application instances using a global constructor function,
# e.g. let app_instance = await createQtAppInstance().
# (as opposed to MODULARIZE=0, where Emscripten creates a global app
# instance object at Javascript eval time)
target_link_options("${wasmTarget}" INTERFACE
"SHELL:-s MODULARIZE=1"
"SHELL:-s EXPORT_NAME=createQtAppInstance")
#simd
if (QT_FEATURE_sse2)
target_compile_options("${wasmTarget}" INTERFACE -O2 -msimd128 -msse -msse2)
endif()
set(disable_exceptions_catching 1)
if (QT_FEATURE_exceptions)
set(disable_exceptions_catching 0)
endif()
target_link_options("${wasmTarget}" INTERFACE "SHELL:-s DISABLE_EXCEPTION_CATCHING=${disable_exceptions_catching}")
if (QT_FEATURE_thread)
target_compile_options("${wasmTarget}" INTERFACE "SHELL:-pthread")
target_link_options("${wasmTarget}" INTERFACE "SHELL:-pthread")
else()
target_link_options("${wasmTarget}" INTERFACE "SHELL:-s ALLOW_MEMORY_GROWTH=1")
endif()
# debug add_compile_options
if ("QT_WASM_SOURCE_MAP=1" IN_LIST QT_QMAKE_DEVICE_OPTIONS)
set(WASM_SOURCE_MAP_BASE "http://localhost:8000/")
if(DEFINED QT_WASM_SOURCE_MAP_BASE)
set(WASM_SOURCE_MAP_BASE "${QT_WASM_SOURCE_MAP_BASE}")
endif()
# Pass --source-map-base on the linker line. This informs the
# browser where to find the source files when debugging.
# -g4 to make source maps for debugging
target_link_options("${wasmTarget}" INTERFACE "-gsource-map" "--source-map-base" "${WASM_SOURCE_MAP_BASE}")
endif()
# a few good defaults to make console more verbose while debugging
target_link_options("${wasmTarget}" INTERFACE $<$<CONFIG:Debug>:
"SHELL:-s DEMANGLE_SUPPORT=1"
"SHELL:-s GL_DEBUG=1"
--profiling-funcs>)
# target_link_options("${wasmTarget}" INTERFACE "SHELL:-s LIBRARY_DEBUG=1") # print out library calls, verbose
# target_link_options("${wasmTarget}" INTERFACE "SHELL:-s SYSCALL_DEBUG=1") # print out sys calls, verbose
# target_link_options("${wasmTarget}" INTERFACE "SHELL:-s FS_LOG=1") # print out filesystem ops, verbose
# target_link_options("${wasmTarget}" INTERFACE "SHELL:-s SOCKET_DEBUG") # print out socket,network data transfer
if ("QT_EMSCRIPTEN_ASYNCIFY=1" IN_LIST QT_QMAKE_DEVICE_OPTIONS)
# Emscripten recommends building with optimizations when using asyncify
# in order to reduce wasm file size, and may also generate broken wasm
# (with "wasm validation error: too many locals" type errors) if optimizations
# are omitted. Enable optimizations also for debug builds.
set(QT_CFLAGS_OPTIMIZE_DEBUG "-Os" CACHE STRING INTERNAL FORCE)
set(QT_FEATURE_optimize_debug ON CACHE BOOL INTERNAL FORCE)
target_link_options("${wasmTarget}" INTERFACE "SHELL:-s ASYNCIFY" "-Os")
target_compile_definitions("${wasmTarget}" INTERFACE QT_HAVE_EMSCRIPTEN_ASYNCIFY)
endif()
# Set ASYNCIFY_IMPORTS unconditionally in order to support enabling asyncify at link time.
target_link_options("${wasmTarget}" INTERFACE "SHELL:-sASYNCIFY_IMPORTS=qt_asyncify_suspend_js,qt_asyncify_resume_js")
if(QT_FEATURE_shared)
set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS TRUE)
# plugins are SIDE_MODULE
target_compile_options("${wasmTarget}" INTERFACE
"$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,MODULE_LIBRARY>:" -s SIDE_MODULE=1>)
target_link_options("${wasmTarget}" INTERFACE
"$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,MODULE_LIBRARY>:" -s SIDE_MODULE=1>)
# shared libs are SIDE_MODULE
target_compile_options("${wasmTarget}" INTERFACE
"$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,SHARED_LIBRARY>:" -s SIDE_MODULE=1>)
target_link_options("${wasmTarget}" INTERFACE
"$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,SHARED_LIBRARY>:" -s SIDE_MODULE=1>)
else()
target_link_options("${wasmTarget}" INTERFACE "SHELL:-s ERROR_ON_UNDEFINED_SYMBOLS=1")
endif()
endfunction()
function(qt_internal_wasm_add_finalizers target)
qt_add_list_file_finalizer(_qt_internal_add_wasm_extra_exported_methods ${target})
endfunction()