wasm: Add helper for pluging preloads

Dynamic linking on WebAssembly involves preloading .so libraries
during startup of application. Normally, those plugin preload
lists are generating manually by user, which can be tedious.
Add a bash script which demonstrates how to call python
programs to generate preload lists.

Pick-to: 6.9
Change-Id: I0a9869ad0d26606f8b33af2c38248cec3088dd0d
Reviewed-by: Alexandru Croitor <[email protected]>

5 files changed, 56 insertions, 14 deletions

diff --git a/cmake/QtBaseGlobalTargets.cmake b/cmake/QtBaseGlobalTargets.cmake
index 1e028c4a72c..2f0a30645e5 100644
--- a/cmake/QtBaseGlobalTargets.cmake
+++ b/cmake/QtBaseGlobalTargets.cmake
@@ -386,9 +386,23 @@ if(APPLE)
 elseif(WASM)
     configure_file("${CMAKE_CURRENT_SOURCE_DIR}/util/wasm/wasmtestrunner/qt-wasmtestrunner.py"
         "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/qt-wasmtestrunner.py" @ONLY)
-
     qt_install(PROGRAMS "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/qt-wasmtestrunner.py"
         DESTINATION "${INSTALL_LIBEXECDIR}")
+
+    if(QT_FEATURE_shared)
+        configure_file("${CMAKE_CURRENT_SOURCE_DIR}/util/wasm/preload/preload_qml_imports.py"
+            "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/preload_qml_imports.py" COPYONLY)
+        configure_file("${CMAKE_CURRENT_SOURCE_DIR}/util/wasm/preload/preload_qt_plugins.py"
+            "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/preload_qt_plugins.py" COPYONLY)
+        configure_file("${CMAKE_CURRENT_SOURCE_DIR}/util/wasm/preload/generate_default_preloads.sh.in"
+            "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/generate_default_preloads.sh.in" COPYONLY)
+        qt_install(PROGRAMS "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/preload_qml_imports.py"
+            DESTINATION "${INSTALL_LIBEXECDIR}")
+        qt_install(PROGRAMS "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/preload_qt_plugins.py"
+            DESTINATION "${INSTALL_LIBEXECDIR}")
+        qt_install(PROGRAMS "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/generate_default_preloads.sh.in"
+            DESTINATION "${INSTALL_LIBEXECDIR}")
+    endif()
 endif()
 
 # Install CI support files to libexec.
diff --git a/src/corelib/Qt6WasmMacros.cmake b/src/corelib/Qt6WasmMacros.cmake
index eae356679bd..e185ef67490 100644
--- a/src/corelib/Qt6WasmMacros.cmake
+++ b/src/corelib/Qt6WasmMacros.cmake
@@ -91,6 +91,15 @@ function(_qt_internal_wasm_add_target_helpers target)
                         ${_target_directory}/qtloader.js COPYONLY)
                     configure_file("${WASM_BUILD_DIR}/plugins/platforms/qtlogo.svg"
                         ${_target_directory}/qtlogo.svg COPYONLY)
+                    if(QT_FEATURE_shared)
+                        set(TARGET_DIR "${_target_directory}")
+                        set(SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+                        set(QT_HOST_DIR "${QT_HOST_PATH}")
+                        set(QT_WASM_DIR "${WASM_BUILD_DIR}")
+                        set(QT_INSTALL_DIR "${QT6_INSTALL_PREFIX}")
+                        configure_file("${WASM_BUILD_DIR}/libexec/generate_default_preloads.sh.in"
+                            "${_target_directory}/generate_default_preloads_for_${target}.sh" @ONLY)
+                    endif()
                 endif()
             endif()
         endif()
diff --git a/util/wasm/preload/generate_default_preloads.sh.in b/util/wasm/preload/generate_default_preloads.sh.in
new file mode 100644
index 00000000000..b38d308fa45
--- /dev/null
+++ b/util/wasm/preload/generate_default_preloads.sh.in
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+TARGET_DIR="@TARGET_DIR@"
+SOURCE_DIR="@SOURCE_DIR@"
+QT_HOST_DIR="@QT_HOST_DIR@"
+QT_WASM_DIR="@QT_WASM_DIR@"
+QT_INSTALL_DIR="@QT_INSTALL_DIR@"
+
+python3 \
+    "$QT_WASM_DIR/libexec/preload_qt_plugins.py" \
+    "$QT_INSTALL_DIR" \
+    "$TARGET_DIR"
+
+python3 \
+    "$QT_WASM_DIR/libexec/preload_qml_imports.py" \
+    "$SOURCE_DIR" \
+    "$QT_HOST_DIR" \
+    "$QT_INSTALL_DIR" \
+    "$TARGET_DIR"
diff --git a/util/wasm/preload/preload_qml_imports.py b/util/wasm/preload/preload_qml_imports.py
index 9af4fa2a282..b78ef5ee744 100755
--- a/util/wasm/preload/preload_qml_imports.py
+++ b/util/wasm/preload/preload_qml_imports.py
@@ -19,10 +19,6 @@ qt_qml_path = "$QTDIR/qml"
 qt_deploy_qml_path = "/qt/qml"
 
 
-def eprint(*args, **kwargs):
-    print(*args, file=sys.stderr, **kwargs)
-
-
 def preload_file(source, destination):
     preload_files.append({"source": source, "destination": destination})
 
@@ -55,24 +51,23 @@ def extract_preload_files_from_imports(imports):
             )
             preload_file(qmldir_source_path, qmldir_destination_path)
         except Exception as e:
-            eprint(e)
             continue
     return libraries
 
 
 if __name__ == "__main__":
-    if len(sys.argv) != 4:
-        print("Usage: python preload_qml_imports.py <qml-source-path> <qt-host-path> <qt-wasm-path>")
+    if len(sys.argv) != 5:
+        print("Usage: python preload_qml_imports.py <qml-source-path> <qt-host-path> <qt-wasm-path> <output-dir>")
         sys.exit(1)
 
     qml_source_path = sys.argv[1]
     qt_host_path = sys.argv[2]
     qt_wasm_path = sys.argv[3]
+    output_dir = sys.argv[4]
 
     qml_import_path = os.path.join(qt_wasm_path, "qml")
     qmlimportsscanner_path = os.path.join(qt_host_path, "libexec/qmlimportscanner")
 
-    eprint("runing qmlimportsscanner")
     command = [qmlimportsscanner_path, "-rootPath", qml_source_path, "-importPath", qml_import_path]
     result = subprocess.run(command, stdout=subprocess.PIPE)
     imports = json.loads(result.stdout)
@@ -98,4 +93,6 @@ if __name__ == "__main__":
         destination = os.path.join("/", library)
         preload_file(source, destination)
 
-    print(json.dumps(preload_files, indent=2))
+    with open(f"{output_dir}/qt_qml_imports.json", "w") as f:
+        f.write(json.dumps(preload_files, indent=2))
+
diff --git a/util/wasm/preload/preload_qt_plugins.py b/util/wasm/preload/preload_qt_plugins.py
index 362d1297320..4b9b3683a70 100755
--- a/util/wasm/preload/preload_qt_plugins.py
+++ b/util/wasm/preload/preload_qt_plugins.py
@@ -27,11 +27,12 @@ def find_so_files(directory):
 
 
 if __name__ == "__main__":
-    if len(sys.argv) != 2:
-        print("Usage: python make_qt_symlinks.py <qt-wasm-path>")
+    if len(sys.argv) != 3:
+        print("Usage: python preload_qt_plugins.py <qt-wasm-path> <output-dir>")
         sys.exit(1)
 
     qt_wasm_path = sys.argv[1]
+    output_dir = sys.argv[2]
 
     # preload all plugins
     plugins = find_so_files(os.path.join(qt_wasm_path, "plugins"))
@@ -47,8 +48,10 @@ if __name__ == "__main__":
     # and QML imports in /qt/plugins and /qt/qml. The qt.conf file is
     # written to the current directory.
     qtconf = "[Paths]\nPrefix = /qt\n"
-    with open("qt.conf", "w") as f:
+    with open(f"{output_dir}/qt.conf", "w") as f:
         f.write(qtconf)
     preload.append({"source": "qt.conf", "destination": "/qt.conf"})
 
-    print(json.dumps(preload, indent=2))
+    with open(f"{output_dir}/qt_plugins.json", "w") as f:
+        f.write(json.dumps(preload, indent=2))
+