wasm: add cmake build support

A few configure defines get changed:
QMAKE_WASM_PTHREAD_POOL_SIZE is now QT_WASM_PTHREAD_POOL_SIZE
QMAKE_WASM_TOTAL_MEMORY is now QT_WASM_INITIAL_MEMORY
QMAKE_WASM_SOURCE_MAP_BASE is now QT_WASM_SOURCE_MAP_BASE

device-option EMSCRIPTEN_ASYNCIFY=1 is QT_EMSCRIPTEN_ASYNCIFY=1

To create source maps for debugging. use
device-option QT_WASM_SOURCE_MAP=1

Task-number: QTBUG-78647
Change-Id: If9f30cd7fb408c386d6d69b5f7b1beecf1ab44b5
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

.prev_configure.cmake

@@ -341,7 +341,7 @@ qt_feature("android-style-assets" PRIVATE
 )
 qt_feature("shared" PUBLIC
     LABEL "Building shared libraries"
-    AUTODETECT NOT UIKIT
+    AUTODETECT NOT UIKIT AND NOT WASM
     CONDITION BUILD_SHARED_LIBS
 )
 qt_feature_definition("shared" "QT_STATIC" NEGATE PREREQUISITE "!defined(QT_SHARED) && !defined(QT_STATIC)")
@@ -837,7 +837,7 @@ qt_feature_definition("concurrent" "QT_NO_CONCURRENT" NEGATE VALUE "1")
 qt_feature("dbus" PUBLIC PRIVATE
     LABEL "Qt D-Bus"
     AUTODETECT NOT UIKIT AND NOT ANDROID
-    CONDITION QT_FEATURE_thread
+    CONDITION QT_FEATURE_thread AND NOT WASM
 )
 qt_feature_definition("dbus" "QT_NO_DBUS" NEGATE VALUE "1")
 qt_feature("dbus-linked" PRIVATE
@@ -866,7 +866,7 @@ qt_feature("printsupport" PRIVATE
 )
 qt_feature("sql" PRIVATE
     LABEL "Qt Sql"
-    CONDITION QT_FEATURE_thread
+    CONDITION QT_FEATURE_thread AND NOT WASM
 )
 qt_feature("testlib" PRIVATE
     LABEL "Qt Testlib"
@@ -1034,12 +1034,18 @@ qt_configure_add_summary_entry(ARGS "pkg-config")
 qt_configure_add_summary_entry(ARGS "libudev")
 qt_configure_add_summary_entry(ARGS "system-zlib")
 qt_configure_add_summary_entry(ARGS "zstd")
+qt_configure_add_summary_entry(ARGS "thread")
 qt_configure_end_summary_section() # end of "Support enabled for" section
 qt_configure_add_report_entry(
     TYPE NOTE
     MESSAGE "Using static linking will disable the use of dynamically loaded plugins. Make sure to import all needed static plugins, or compile needed modules into the library."
     CONDITION NOT QT_FEATURE_shared
 )
+qt_configure_add_report_entry(
+    TYPE NOTE
+    MESSAGE "Using pthreads"
+    CONDITION QT_FEATURE_thread
+)
 qt_configure_add_report_entry(
     TYPE ERROR
     MESSAGE "Debug build wihtout Release build is not currently supported on ios see QTBUG-71990. Use -debug-and-release."

CMakeLists.txt

@@ -94,6 +94,12 @@ if(NOT QT_BUILD_STANDALONE_TESTS)
     # Needed when building qtbase for android.
     include(src/corelib/Qt6AndroidMacros.cmake)
 
+    if(WASM)
+        # Needed when building for WebAssembly.
+        include(cmake/QtWasmHelpers.cmake)
+        qt_internal_setup_wasm_target_properties(Platform)
+    endif()
+
     # Set up optimization flags like in qmake.
     # This function must be called after the global QT_FEATURE_xxx variables have been set up,
     # aka after QtBaseGlobalTargets is processed.

cmake/QtAutoDetect.cmake

@@ -5,6 +5,64 @@
 # Make sure to not run detection when building standalone tests, because the detection was already
 # done when initially configuring qtbase.
 
+
+function(qt_auto_detect_wasm)
+    if("${QT_QMAKE_TARGET_MKSPEC}" STREQUAL "wasm-emscripten" AND DEFINED ENV{EMSDK})
+        if(NOT DEFINED QT_AUTODETECT_WASM)
+            set(QT_AUTODETECT_WASM TRUE CACHE BOOL "")
+            # detect EMSCRIPTEN_ROOT path
+            file(READ "$ENV{EMSDK}/.emscripten" ver)
+            string(REGEX MATCH "EMSCRIPTEN_ROOT.*$" EMROOT "${ver}")
+            string(REGEX MATCH "'([^' ]*)'" EMROOT2 "${EMROOT}")
+            string(REPLACE "'" "" EMROOT_PATH "${EMROOT2}")
+
+            # get emscripten version
+            if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+                set (EXECUTE_COMMANDPATH "$ENV{EMSDK}/${EMROOT_PATH}/emcc.bat")
+            else()
+                set (EXECUTE_COMMANDPATH "$ENV{EMSDK}/${EMROOT_PATH}/emcc")
+            endif()
+
+            file(TO_NATIVE_PATH "${EXECUTE_COMMANDPATH}" EXECUTE_COMMAND)
+            execute_process(COMMAND ${EXECUTE_COMMAND} --version
+                OUTPUT_VARIABLE emOutput
+                OUTPUT_STRIP_TRAILING_WHITESPACE
+                ERROR_VARIABLE emrun_error
+                RESULT_VARIABLE result)
+            if(NOT emOutput)
+                message(FATAL_ERROR
+                        "Can't determine Emscripten version! Error: ${emrun_error}")
+            endif()
+            string(REGEX MATCH "[0-9]+\\.[0-9]+\\.[0-9]+" CMAKE_EMSDK_REGEX_VERSION "${emOutput}")
+            set(EMCC_VERSION "${CMAKE_EMSDK_REGEX_VERSION}" CACHE STRING  INTERNAL FORCE)
+
+            # find toolchain file
+            if(NOT DEFINED CMAKE_TOOLCHAIN_FILE)
+                set(wasm_toolchain_file "$ENV{EMSDK}/${EMROOT_PATH}/cmake/Modules/Platform/Emscripten.cmake")
+                set(CMAKE_TOOLCHAIN_FILE "${wasm_toolchain_file}" CACHE STRING "" FORCE)
+            endif()
+
+            if(EXISTS "${CMAKE_TOOLCHAIN_FILE}")
+                message(STATUS "Emscripten ${CMAKE_EMSDK_REGEX_VERSION} toolchain file detected at ${CMAKE_TOOLCHAIN_FILE}")
+            else()
+                message(FATAL_ERROR "Cannot find the toolchain file Emscripten.cmake. "
+                "Please specify the toolchain file with -DCMAKE_TOOLCHAIN_FILE=<file>.")
+            endif()
+
+            if(NOT DEFINED BUILD_SHARED_LIBS)
+                set(BUILD_SHARED_LIBS OFF CACHE BOOL "Build Qt statically or dynamically" FORCE)
+            endif()
+
+            if(BUILD_SHARED_LIBS)
+                message(FATAL_ERROR
+                    "Building Qt for ${CMAKE_SYSTEM_NAME} as shared libraries is not supported.")
+            endif()
+            # this version of Qt needs this version of emscripten
+            set(QT_EMCC_RECOMMENDED_VERSION 2.0.14 CACHE STRING INTERNAL FORCE)
+        endif()
+    endif()
+endfunction()
+
 function(qt_auto_detect_cmake_generator)
     if(NOT CMAKE_GENERATOR MATCHES "Ninja" AND NOT QT_SILENCE_CMAKE_GENERATOR_WARNING)
         message(WARNING
@@ -340,3 +398,4 @@ qt_auto_detect_ios()
 qt_auto_detect_android()
 qt_auto_detect_vpckg()
 qt_auto_detect_pch()
+qt_auto_detect_wasm()

cmake/QtBaseConfigureTests.cmake

@@ -32,7 +32,7 @@ function(qt_run_config_test_architecture)
     # With emscripten the application entry point is a .js file (to be run with node for example),
     # but the real "data" is in the .wasm file, so that's where we need to look for the ABI, etc.
     # information.
-    if (EMSCRIPTEN)
+    if (WASM)
         set(_arch_file_suffix ".wasm")
     endif()
 

cmake/QtBaseGlobalTargets.cmake

@@ -214,6 +214,7 @@ qt_copy_or_install(FILES
                    cmake/QtTestHelpers.cmake
                    cmake/QtToolchainHelpers.cmake
                    cmake/QtToolHelpers.cmake
+                   cmake/QtWasmHelpers.cmake
                    cmake/QtWrapperScriptHelpers.cmake
                    cmake/QtWriteArgsFile.cmake
     DESTINATION "${__GlobalConfig_install_dir}"

cmake/QtBuild.cmake

@@ -302,7 +302,7 @@ elseif(IOS)
     set(QT_DEFAULT_MKSPEC macx-ios-clang)
 elseif(APPLE)
     set(QT_DEFAULT_MKSPEC macx-clang)
-elseif(EMSCRIPTEN)
+elseif(WASM)
     set(QT_DEFAULT_MKSPEC wasm-emscripten)
 elseif(QNX)
     # Certain POSIX defines are not set if we don't compile with -std=gnuXX

cmake/QtBuildInternals/QtBuildInternalsConfig.cmake

@@ -120,7 +120,7 @@ function(qt_build_internals_disable_pkg_config_if_needed)
     set(pkg_config_enabled ON)
     qt_build_internals_find_pkg_config_executable()
 
-    if(APPLE OR WIN32 OR QNX OR ANDROID OR (NOT PKG_CONFIG_EXECUTABLE))
+    if(APPLE OR WIN32 OR QNX OR ANDROID OR WASM OR (NOT PKG_CONFIG_EXECUTABLE))
         set(pkg_config_enabled OFF)
     endif()
 

cmake/QtCompilerOptimization.cmake

@@ -136,7 +136,7 @@ endif()
 # TODO: Missing mkspecs flags we don't handle below: win32-clang-g++, win32-clang-msvc, rtems-base
 #
 # gcc and clang base
-if(GCC OR CLANG)
+if(GCC OR CLANG AND NOT WASM)
     set(QT_CFLAGS_OPTIMIZE "-O2")
     set(QT_CFLAGS_OPTIMIZE_FULL "-O3")
     set(QT_CFLAGS_OPTIMIZE_DEBUG "-Og")
@@ -187,3 +187,10 @@ if(ICC)
         set(QT_CFLAGS_OPTIMIZE_SIZE "-Os")
     endif()
 endif()
+
+if(WASM)
+    set(QT_CFLAGS_OPTIMIZE "-O2")
+    set(QT_CFLAGS_OPTIMIZE_FULL "-O3")
+    set(QT_CFLAGS_OPTIMIZE_SIZE "-Os")
+    set(QT_CFLAGS_OPTIMIZE_DEBUG "-g2")
+endif()

cmake/QtExecutableHelpers.cmake

@@ -33,6 +33,9 @@ function(qt_internal_add_executable name)
             PROPERTY EXCLUDE_FROM_ALL "$<NOT:$<CONFIG:${QT_MULTI_CONFIG_FIRST_CONFIG}>>")
     endif()
 
+    if(WASM)
+        qt6_wasm_add_target_helpers("${name}")
+    endif()
     if (arg_VERSION)
         if(arg_VERSION MATCHES "[0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+")
             # nothing to do

cmake/QtFlagHandlingHelpers.cmake

@@ -88,7 +88,7 @@ function(qt_internal_apply_gc_binaries target visibility)
         message(FATAL_ERROR "Visibitily setting must be one of PRIVATE, INTERFACE or PUBLIC.")
     endif()
 
-    if ((GCC OR CLANG) AND NOT EMSCRIPTEN AND NOT UIKIT AND NOT MSVC)
+    if ((GCC OR CLANG) AND NOT WASM AND NOT UIKIT AND NOT MSVC)
         if(APPLE)
             set(gc_sections_flag "-Wl,-dead_strip")
         elseif(SOLARIS)
@@ -101,7 +101,7 @@ function(qt_internal_apply_gc_binaries target visibility)
         target_link_options("${target}" ${visibility} "${gc_sections_flag}")
     endif()
 
-    if((GCC OR CLANG OR ICC) AND NOT EMSCRIPTEN AND NOT UIKIT AND NOT MSVC)
+    if((GCC OR CLANG OR ICC) AND NOT WASM AND NOT UIKIT AND NOT MSVC)
         set(split_sections_flags "-ffunction-sections" "-fdata-sections")
     endif()
     if(split_sections_flags)

cmake/QtModuleHelpers.cmake

@@ -552,7 +552,9 @@ set(QT_CMAKE_EXPORT_NAMESPACE ${QT_CMAKE_EXPORT_NAMESPACE})")
         PRIVATE_HEADER DESTINATION ${INSTALL_INCLUDEDIR}/${module_include_name}/${PROJECT_VERSION}/${module}/private
         )
 
-    qt_apply_rpaths(TARGET "${target}" INSTALL_PATH "${INSTALL_LIBDIR}" RELATIVE_RPATH)
+    if(BUILD_SHARED_LIBS)
+        qt_apply_rpaths(TARGET "${target}" INSTALL_PATH "${INSTALL_LIBDIR}" RELATIVE_RPATH)
+    endif()
 
     if (ANDROID AND NOT arg_HEADER_MODULE)
         # Record install library location so it can be accessed by

cmake/QtPlatformSupport.cmake

@@ -16,7 +16,7 @@ qt_set01(QNX CMAKE_SYSTEM_NAME STREQUAL "QNX") # FIXME: How to identify this?
 qt_set01(OPENBSD CMAKE_SYSTEM_NAME STREQUAL "OpenBSD") # FIXME: How to identify this?
 qt_set01(FREEBSD CMAKE_SYSTEM_NAME STREQUAL "FreeBSD") # FIXME: How to identify this?
 qt_set01(NETBSD CMAKE_SYSTEM_NAME STREQUAL "NetBSD") # FIXME: How to identify this?
-qt_set01(WASM CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
+qt_set01(WASM CMAKE_SYSTEM_NAME STREQUAL "Emscripten" OR EMSCRIPTEN)
 
 qt_set01(BSD APPLE OR OPENBSD OR FREEBSD OR NETBSD)
 

cmake/QtPluginHelpers.cmake

@@ -338,7 +338,9 @@ function(qt_internal_add_plugin target)
                    NAMESPACE ${QT_CMAKE_EXPORT_NAMESPACE}::
                    DESTINATION "${config_install_dir}"
         )
-        qt_apply_rpaths(TARGET "${target}" INSTALL_PATH "${install_directory}" RELATIVE_RPATH)
+        if(BUILD_SHARED_LIBS)
+            qt_apply_rpaths(TARGET "${target}" INSTALL_PATH "${install_directory}" RELATIVE_RPATH)
+        endif()
     endif()
 
     if (NOT arg_ALLOW_UNDEFINED_SYMBOLS)

cmake/QtPriHelpers.cmake

@@ -563,7 +563,6 @@ QT_PATCH_VERSION = ${PROJECT_VERSION_PATCH}
         list(APPEND extra_statements "QT_LIBINFIX = ${QT_LIBINFIX}")
     endif()
 
-    # TODO: Add QT_EMCC_VERSION when WASM is ported over.
     if(APPLECLANG)
         set(compiler_version_major_var_name "QT_APPLE_CLANG_MAJOR_VERSION")
         set(compiler_version_minor_var_name "QT_APPLE_CLANG_MINOR_VERSION")
@@ -603,6 +602,10 @@ QT_PATCH_VERSION = ${PROJECT_VERSION_PATCH}
 
     list(APPEND extra_statements "QT_EDITION = Open Source")
 
+    if(WASM)
+        list(APPEND extra_statements
+            "QT_EMCC_VERSION = ${EMCC_VERSION}")
+    endif()
     if(extra_statements)
         string(REPLACE ";" "\n" extra_statements "${extra_statements}")
         string(APPEND content "\n${extra_statements}\n")

cmake/QtWasmHelpers.cmake

@@ -0,0 +1,92 @@
+
+function (qt_internal_setup_wasm_target_properties wasmTarget)
+
+    target_link_options("${wasmTarget}" INTERFACE "SHELL:-s EXIT_RUNTIME=1"
+    "SHELL:-s ERROR_ON_UNDEFINED_SYMBOLS=1"
+    "SHELL:-s EXTRA_EXPORTED_RUNTIME_METHODS=[UTF16ToString,stringToUTF16]"
+    "SHELL:-s USE_WEBGL2=1"
+    "--bind"
+    "SHELL:-s FETCH=1")
+
+    # Hardcode wasm memory size. Emscripten does not currently support memory growth
+    # (ALLOW_MEMORY_GROWTH) in pthreads mode, and requires specifying the memory size
+    # at build time. Further, browsers limit the maximum initial memory size to 1GB.
+    # QT_WASM_INITIAL_MEMORY must be a multiple of 64KB (i.e. 65536)
+    if(NOT DEFINED QT_WASM_INITIAL_MEMORY AND QT_FEATURE_thread)
+        set(QT_WASM_INITIAL_MEMORY "1GB")
+    endif()
+
+    if(DEFINED QT_WASM_INITIAL_MEMORY)
+        target_link_options("${wasmTarget}" INTERFACE "SHELL:-s INITIAL_MEMORY=${QT_WASM_INITIAL_MEMORY}")
+        message("Setting INITIAL_MEMORY to ${QT_WASM_INITIAL_MEMORY}")
+    endif()
+
+    if (QT_FEATURE_opengles3)
+        target_link_options("${wasmTarget}" INTERFACE "SHELL:-s FULL_ES3=1")
+
+        target_link_options("${wasmTarget}" INTERFACE "SHELL:-s FULL_ES3=1"
+            "SHELL:-s MAX_WEBGL_VERSION=2"
+            "SHELL:-s WEBGL2_BACKWARDS_COMPATIBILITY_EMULATION=1")
+    else()
+        target_link_options("${wasmTarget}" INTERFACE "SHELL:-s FULL_ES2=1")
+    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("${wasmTarget}" INTERFACE "SHELL:-s USE_PTHREADS=1")
+        target_link_options("${wasmTarget}" INTERFACE "SHELL:-s USE_PTHREADS=1")
+
+        if(DEFINED QT_WASM_PTHREAD_POOL_SIZE)
+            target_link_options("${wasmTarget}" INTERFACE "SHELL:-s PTHREAD_POOL_SIZE=${QT_WASM_PTHREAD_POOL_SIZE}")
+            message("Setting PTHREAD_POOL_SIZE to ${QT_WASM_PTHREAD_POOL_SIZE}")
+        endif()
+
+    else()
+        target_link_options("${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  "-g4" "--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"
+        SHELL:"-s ASSERTIONS=2"
+        --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()
+endfunction()

configure.cmake

@@ -339,7 +339,7 @@ qt_feature("android-style-assets" PRIVATE
 )
 qt_feature("shared" PUBLIC
     LABEL "Building shared libraries"
-    AUTODETECT NOT UIKIT
+    AUTODETECT NOT UIKIT AND NOT WASM
     CONDITION BUILD_SHARED_LIBS
 )
 qt_feature_definition("shared" "QT_STATIC" NEGATE PREREQUISITE "!defined(QT_SHARED) && !defined(QT_STATIC)")
@@ -600,6 +600,7 @@ qt_feature("c11" PUBLIC
 qt_feature("precompile_header"
     LABEL "Using precompiled headers"
     CONDITION BUILD_WITH_PCH
+    AUTODETECT NOT WASM
 )
 qt_feature_config("precompile_header" QMAKE_PRIVATE_CONFIG)
 set(__qt_ltcg_detected FALSE)
@@ -848,7 +849,7 @@ qt_feature_definition("concurrent" "QT_NO_CONCURRENT" NEGATE VALUE "1")
 qt_feature("dbus" PUBLIC PRIVATE
     LABEL "Qt D-Bus"
     AUTODETECT NOT UIKIT AND NOT ANDROID
-    CONDITION QT_FEATURE_thread
+    CONDITION QT_FEATURE_thread AND NOT WASM
 )
 qt_feature_definition("dbus" "QT_NO_DBUS" NEGATE VALUE "1")
 qt_feature("dbus-linked" PRIVATE
@@ -877,7 +878,7 @@ qt_feature("printsupport" PRIVATE
 )
 qt_feature("sql" PRIVATE
     LABEL "Qt Sql"
-    CONDITION QT_FEATURE_thread
+    CONDITION QT_FEATURE_thread AND NOT WASM
 )
 qt_feature("testlib" PRIVATE
     LABEL "Qt Testlib"
@@ -1050,6 +1051,7 @@ qt_configure_add_summary_entry(ARGS "pkg-config")
 qt_configure_add_summary_entry(ARGS "libudev")
 qt_configure_add_summary_entry(ARGS "system-zlib")
 qt_configure_add_summary_entry(ARGS "zstd")
+qt_configure_add_summary_entry(ARGS "thread")
 qt_configure_end_summary_section() # end of "Support enabled for" section
 qt_configure_add_report_entry(
     TYPE NOTE
@@ -1094,9 +1096,22 @@ qt_configure_add_report_entry(
     MESSAGE "Setting a library infix is not supported for framework builds."
     CONDITION QT_FEATURE_framework AND DEFINED QT_LIBINFIX
 )
+qt_configure_add_report_entry(
+    TYPE NOTE
+    MESSAGE "Using pthreads"
+    CONDITION QT_FEATURE_thread
+)
+qt_configure_add_report_entry(
+    TYPE WARNING
+    MESSAGE "You should use the recommended Wasm version ${QT_EMCC_RECOMMENDED_VERSION} with this Qt. You have ${EMCC_VERSION}."
+    CONDITION WASM AND NOT ${EMCC_VERSION} MATCHES ${QT_EMCC_RECOMMENDED_VERSION}
+)
+if(WASM)
+    qt_extra_definition("QT_EMCC_VERSION" "\"${EMCC_VERSION}\"" PUBLIC)
+endif()
 # special case end
-
 qt_extra_definition("QT_VERSION_STR" "\"${PROJECT_VERSION}\"" PUBLIC)
 qt_extra_definition("QT_VERSION_MAJOR" ${PROJECT_VERSION_MAJOR} PUBLIC)
 qt_extra_definition("QT_VERSION_MINOR" ${PROJECT_VERSION_MINOR} PUBLIC)
 qt_extra_definition("QT_VERSION_PATCH" ${PROJECT_VERSION_PATCH} PUBLIC)
+

configure.json

@@ -677,7 +677,7 @@
         },
         "shared": {
             "label": "Building shared libraries",
-            "autoDetect": "!config.uikit",
+            "autoDetect": "!config.uikit && !config.wasm",
             "condition": "!config.integrity && !config.wasm && !config.rtems",
             "output": [
                 "shared",
@@ -1010,6 +1010,7 @@
         "precompile_header": {
             "label": "Using precompiled headers",
             "condition": "tests.precompile_header",
+            "autodetect": "!config.wasm",
             "output": [
                 "privateConfig",
                 { "type": "varRemove", "negative": true, "name": "CONFIG", "value": "'precompile_header'" }
@@ -1337,7 +1338,7 @@
         "dbus": {
             "label": "Qt D-Bus",
             "autoDetect": "!config.uikit && !config.android",
-            "condition": "features.thread",
+            "condition": "features.thread && !config.wasm",
             "output": [ "privateFeature", "feature" ]
         },
         "dbus-linked": {
@@ -1378,7 +1379,7 @@
         },
         "sql": {
             "label": "Qt Sql",
-            "condition": "features.thread",
+            "condition": "features.thread && !config.wasm",
             "output": [ "privateFeature" ]
         },
         "testlib": {
@@ -1512,8 +1513,9 @@
             "message": "Qt requires a compliant STL library."
         },
         {
-            "type": "emccVersion",
+            "type": "note",
-            "condition": "config.wasm"
+            "condition": "features.thread",
+            "message": "Using pthreads"
         },
         {
             "type": "error",
@@ -1673,7 +1675,8 @@
                 "pkg-config",
                 "libudev",
                 "system-zlib",
-                "zstd"
+                "zstd",
+                "thread"
             ]
         }
     ]

mkspecs/features/wasm/wasm.prf

@@ -13,8 +13,8 @@ exists($$QMAKE_QT_CONFIG) {
         # Create worker threads at startup. This is supposed to be an optimization,
         # however exceeding the pool size has been obesverved to hang the application.
         POOL_SIZE = 4
-        !isEmpty(QMAKE_WASM_PTHREAD_POOL_SIZE) {
+        !isEmpty(QT_WASM_PTHREAD_POOL_SIZE) {
-            POOL_SIZE = $$QMAKE_WASM_PTHREAD_POOL_SIZE
+            POOL_SIZE = $$QT_WASM_PTHREAD_POOL_SIZE
         }
 
         message("Setting PTHREAD_POOL_SIZE to" $$POOL_SIZE)
@@ -23,18 +23,18 @@ exists($$QMAKE_QT_CONFIG) {
         EMCC_THREAD_LFLAGS += -s ALLOW_MEMORY_GROWTH=1
     }
 
-     qtConfig(thread) | !isEmpty(QMAKE_WASM_TOTAL_MEMORY) {
+     qtConfig(thread) | !isEmpty(QT_WASM_INITIAL_MEMORY) {
 
             # Hardcode wasm memory size. Emscripten does not currently support memory growth
             # (ALLOW_MEMORY_GROWTH) in pthreads mode, and requires specifying the memory size
             # at build time. Further, browsers limit the maximum initial memory size to 1GB.
-            # QMAKE_WASM_TOTAL_MEMORY must be a multiple of 64KB
+            # QT_WASM_INITIAL_MEMORY must be a multiple of 64KB
-            TOTAL_MEMORY = 1GB
+            INITIAL_MEMORY = 1GB
-            !isEmpty(QMAKE_WASM_TOTAL_MEMORY) {
+            !isEmpty(QT_WASM_INITIAL_MEMORY) {
-                TOTAL_MEMORY = $$QMAKE_WASM_TOTAL_MEMORY
+                INITIAL_MEMORY = $$QT_WASM_INITIAL_MEMORY
             }
-            message("Setting TOTAL_MEMORY to" $$TOTAL_MEMORY)
+            message("Setting INITIAL_MEMORY to" $$INITIAL_MEMORY)
-            EMCC_THREAD_LFLAGS += -s TOTAL_MEMORY=$$TOTAL_MEMORY
+            EMCC_THREAD_LFLAGS += -s INITIAL_MEMORY=$$INITIAL_MEMORY
     }
     QMAKE_LFLAGS       += $$EMCC_THREAD_LFLAGS
     QMAKE_LFLAGS_DEBUG += $$EMCC_THREAD_LFLAGS
@@ -117,9 +117,9 @@ qtConfTest_emccVersion()
 # Pass --source-map-base on the linker line. This informs the
 # browser where to find the source files when debugging.
 WASM_SOURCE_MAP_BASE = http://localhost:8000/
-!isEmpty(QMAKE_WASM_SOURCE_MAP_BASE):\
+!isEmpty(QT_WASM_SOURCE_MAP_BASE):\
-    WASM_SOURCE_MAP_BASE = $$QMAKE_WASM_SOURCE_MAP_BASE
+    WASM_SOURCE_MAP_BASE = $$QT_WASM_SOURCE_MAP_BASE
-CONFIG(debug): QMAKE_LFLAGS += --source-map-base $$WASM_SOURCE_MAP_BASE
+CONFIG(debug): QMAKE_LFLAGS += -g4 --source-map-base $$WASM_SOURCE_MAP_BASE
 
 # Creates the stand-alone version of the library from bitcode
 !static:contains(TEMPLATE, .*lib): {

mkspecs/wasm-emscripten/qmake.conf

@@ -8,11 +8,11 @@ include(../common/clang.conf)
 load(device_config)
 load(emcc_ver)
 
-# Support enabling asyncify by configuring with "-device-option EMSCRIPTEN_ASYNCIFY=1"
+# Support enabling asyncify by configuring with "-device-option QT_EMSCRIPTEN_ASYNCIFY=1"
-!isEmpty(EMSCRIPTEN_ASYNCIFY): {
+!isEmpty(QT_EMSCRIPTEN_ASYNCIFY): {
-    !equals(EMSCRIPTEN_ASYNCIFY, 1):!equals(EMSCRIPTEN_ASYNCIFY, 0): \
+    !equals(QT_EMSCRIPTEN_ASYNCIFY, 1):!equals(QT_EMSCRIPTEN_ASYNCIFY, 0): \
-        message(Error: The value for EMSCRIPTEN_ASYNCIFY must be 0 or 1)
+        message(Error: The value for QT_EMSCRIPTEN_ASYNCIFY must be 0 or 1)
-    equals(EMSCRIPTEN_ASYNCIFY, 1): {
+    equals(QT_EMSCRIPTEN_ASYNCIFY, 1): {
         QMAKE_CFLAGS += -DQT_HAVE_EMSCRIPTEN_ASYNCIFY
         QMAKE_CXXFLAGS += -DQT_HAVE_EMSCRIPTEN_ASYNCIFY
         QMAKE_LFLAGS += -s ASYNCIFY
@@ -56,7 +56,7 @@ EMCC_COMMON_LFLAGS_DEBUG = \
     -s GL_DEBUG=1 \
     --profiling-funcs
 
-QMAKE_LFLAGS_DEBUG  += -g4
+QMAKE_LFLAGS_DEBUG  += -g2
 QMAKE_LFLAGS_RELEASE  += -O2
 
 QMAKE_COMPILER         += emscripten

src/corelib/CMakeLists.txt

@@ -20,6 +20,10 @@ if(ANDROID)
     set(corelib_extra_cmake_files
         "${CMAKE_CURRENT_SOURCE_DIR}/${QT_CMAKE_EXPORT_NAMESPACE}AndroidMacros.cmake")
 endif()
+if(WASM)
+    set(corelib_extra_cmake_files
+        "${CMAKE_CURRENT_SOURCE_DIR}/${QT_CMAKE_EXPORT_NAMESPACE}WasmMacros.cmake")
+endif()
 # special case end
 
 #####################################################################

src/corelib/Qt6CoreConfigExtras.cmake.in

@@ -47,3 +47,7 @@ set(_Qt6CTestMacros "${_Qt6CoreConfigDir}/Qt6CTestMacros.cmake")
 if(ANDROID_PLATFORM)
     include("${CMAKE_CURRENT_LIST_DIR}/@QT_CMAKE_EXPORT_NAMESPACE@AndroidMacros.cmake")
 endif()
+
+if(EMSCRIPTEN)
+    include("${CMAKE_CURRENT_LIST_DIR}/@QT_CMAKE_EXPORT_NAMESPACE@WasmMacros.cmake")
+endif()

src/corelib/Qt6CoreMacros.cmake

@@ -559,6 +559,9 @@ function(qt6_finalize_executable target)
         qt6_android_generate_deployment_settings("${target}")
         qt6_android_add_apk_target("${target}")
     endif()
+    if(EMSCRIPTEN)
+        qt_wasm_add_target_helpers("${target}")
+    endif()
 endfunction()
 
 if(NOT QT_NO_CREATE_VERSIONLESS_FUNCTIONS)

src/corelib/Qt6WasmMacros.cmake

@@ -0,0 +1,31 @@
+
+function(qt6_wasm_add_target_helpers target)
+    # copy in Qt HTML/JS launch files for apps
+    get_target_property(targetType "${target}" TYPE)
+    if("${targetType}" STREQUAL "EXECUTABLE")
+
+        set(APPNAME ${target})
+
+        if(QT6_INSTALL_PREFIX)
+            set(WASM_BUILD_DIR "${QT6_INSTALL_PREFIX}")
+        elseif(QT_BUILD_DIR)
+            set(WASM_BUILD_DIR "${QT_BUILD_DIR}")
+        endif()
+
+        configure_file("${WASM_BUILD_DIR}/plugins/platforms/wasm_shell.html"
+            "${target}.html")
+        configure_file("${WASM_BUILD_DIR}/plugins/platforms/qtloader.js"
+            qtloader.js COPYONLY)
+        configure_file("${WASM_BUILD_DIR}/plugins/platforms/qtlogo.svg"
+            qtlogo.svg COPYONLY)
+
+    endif()
+endfunction()
+
+if(NOT QT_NO_CREATE_VERSIONLESS_FUNCTIONS)
+    function(qt_wasm_add_target_helpers)
+        if(QT_DEFAULT_MAJOR_VERSION EQUAL 6)
+            qt6_wasm_add_target_helpers(${ARGV})
+        endif()
+    endfunction()
+endif()

src/gui/configure.cmake

@@ -389,10 +389,19 @@ ioctl(fd, FBIOGET_VSCREENINFO, &vinfo);
 ")
 
 # opengles3
+# special case begin
+if(WASM)
+    set(extra_compiler_options "-s FULL_ES3=1")
+endif()
+# special case end
+
 qt_config_compile_test(opengles3
     LABEL "OpenGL ES 3.0"
     LIBRARIES
         GLESv2::GLESv2
+# special case begin
+    COMPILE_OPTIONS ${extra_compiler_options}
+# special case end
     CODE
 "#ifdef __APPLE__
 #  include <OpenGLES/ES3/gl.h>

src/plugins/platforms/CMakeLists.txt

@@ -47,7 +47,7 @@ if(HAIKU)
     # add_subdirectory(haiku) # special case TODO
 endif()
 if(WASM)
-    # add_subdirectory(wasm) # special case TODO
+     add_subdirectory(wasm)
 endif()
 if(QT_FEATURE_integrityfb)
     # add_subdirectory(integrity) # special case TODO

src/plugins/platforms/wasm/CMakeLists.txt

@@ -0,0 +1,78 @@
+# Generated from wasm.pro.
+
+#####################################################################
+## QWasmIntegrationPlugin Plugin:
+#####################################################################
+
+qt_internal_add_plugin(QWasmIntegrationPlugin
+    OUTPUT_NAME qwasm
+    DEFAULT_IF ${QT_QPA_DEFAULT_PLATFORM} MATCHES wasm # special case
+    TYPE platforms
+    STATIC
+    SOURCES
+        main.cpp
+        qwasmclipboard.cpp qwasmclipboard.h
+        qwasmcompositor.cpp qwasmcompositor.h
+        qwasmcursor.cpp qwasmcursor.h
+        qwasmeventdispatcher.cpp qwasmeventdispatcher.h
+        qwasmeventtranslator.cpp qwasmeventtranslator.h
+        qwasmfontdatabase.cpp qwasmfontdatabase.h
+        qwasmintegration.cpp qwasmintegration.h
+        qwasmoffscreensurface.cpp qwasmoffscreensurface.h
+        qwasmopenglcontext.cpp qwasmopenglcontext.h
+        qwasmscreen.cpp qwasmscreen.h
+        qwasmservices.cpp qwasmservices.h
+        qwasmstring.cpp qwasmstring.h
+        qwasmstylepixmaps_p.h
+        qwasmtheme.cpp qwasmtheme.h
+        qwasmwindow.cpp qwasmwindow.h
+    DEFINES
+        QT_EGL_NO_X11
+        QT_NO_FOREACH
+    PUBLIC_LIBRARIES
+        Qt::Core
+        Qt::CorePrivate
+        Qt::Gui
+        Qt::GuiPrivate
+)
+
+# Resources:
+set_source_files_properties("${QT_SOURCE_TREE}/src/3rdparty/wasm/Vera.ttf" PROPERTIES QT_RESOURCE_ALIAS "Vera.ttf")
+set_source_files_properties("${QT_SOURCE_TREE}/src/3rdparty/wasm/DejaVuSans.ttf" PROPERTIES QT_RESOURCE_ALIAS "DejaVuSans.ttf")
+set_source_files_properties("${QT_SOURCE_TREE}/src/3rdparty/wasm/DejaVuSansMono.ttf" PROPERTIES QT_RESOURCE_ALIAS "DejaVuSansMono.ttf")
+
+set(wasmfonts_resource_files
+    "${QT_SOURCE_TREE}/src/3rdparty/wasm/Vera.ttf"
+    "${QT_SOURCE_TREE}/src/3rdparty/wasm/DejaVuSans.ttf"
+    "${QT_SOURCE_TREE}/src/3rdparty/wasm/DejaVuSansMono.ttf"
+)
+
+qt_internal_add_resource(QWasmIntegrationPlugin "wasmfonts"
+    PREFIX
+        "/fonts"
+    FILES
+        ${wasmfonts_resource_files}
+)
+qt_internal_extend_target(QWasmIntegrationPlugin CONDITION QT_FEATURE_opengl
+    SOURCES
+        qwasmbackingstore.cpp qwasmbackingstore.h
+    PUBLIC_LIBRARIES
+        Qt::OpenGL
+        Qt::OpenGLPrivate
+)
+
+#### Keys ignored in scope 4:.:.:wasm.pro:NOT TARGET___equals____ss_QT_DEFAULT_QPA_PLUGIN:
+# PLUGIN_EXTENDS = "-"
+
+qt_copy_or_install(FILES
+    wasm_shell.html
+    DESTINATION "${CMAKE_INSTALL_PREFIX}/plugins/platforms/"
+)
+qt_copy_or_install(FILES
+    qtloader.js
+    DESTINATION "${CMAKE_INSTALL_PREFIX}/plugins/platforms/"
+)
+qt_copy_or_install(FILES
+    qtlogo.svg
+    DESTINATION "${CMAKE_INSTALL_PREFIX}/plugins/platforms/"
+)