subagent transcript

session 17f09f89 · workflow wf_4e894f41
← 17f09f89 · archive
delegated task
You are working on the FreeCAD -> WebAssembly port. Ground EVERYTHING in the real code; do not guess. - Source tree: /home/magik6k/lcad-wasm/freecad-p
▸ Magik
You are working on the FreeCAD -> WebAssembly port. Ground EVERYTHING in the real code; do not guess. - Source tree: /home/magik6k/lcad-wasm/freecad-port/FreeCAD (git branch wasm-port). CMake build dir (out-of-source, already configured): /opt/toolchains/src/freecad-gui-build — read /opt/toolchains/src/freecad-gui-build/CMakeCache.txt for BUILD_* flags and dep paths. Build binary: bin/FreeCAD.wasm (~180 MB). - Toolchain: emscripten, ASYNCIFY + JS exceptions (-fexceptions), SINGLE-THREADED (no pthreads). Static CPython 3.14 + static Qt 6.11 (wasm) + static OCCT + static Coin3D. Everything is statically linked; there is NO dlopen — Python C-extension modules are registered statically via PyImport_AppendInittab in the generated file src/Main/WasmInittab.cpp / WasmInittabGui.cpp (see also freecadWasmRegisterInittab in src/Main/MainGui.cpp). - CRITICAL wasm constraints you MUST check for and design around: (1) THREADING HANGS: any std::thread ctor / std::async(default or async policy) / QThreadPool / QtConcurrent / QThread worker HANGS or throws (no pthreads). Fix pattern: force synchronous/deferred on __EMSCRIPTEN__ (e.g. std::launch::deferred), or #ifndef FC_OS_WASM guard the worker and run inline. Example already in-tree: Mod/Sketcher/App/planegcs/GCS.cpp forced std::launch::deferred; App/Application.cpp guards _recomputeThread with #ifndef FC_OS_WASM; Gui/ProgressBar.cpp skips qApp->processEvents() on __EMSCRIPTEN__. (2) MODAL DIALOGS / NESTED EVENT LOOPS: QDialog::exec()/QMessageBox::exec()/QEventLoop::exec() may deadlock under asyncify when driven from outside the main loop. Task-panel (docked, non-modal) dialogs are preferred. (3) Reentrant ccalls from JS during asyncify suspend corrupt state — a QTimer command-pump (/fc-cmd.py) exists for JS->Python. QtWebEngine has NO wasm port (Web workbench / in-app help / real Start page can't use it). (4) Wasm guards used in-tree: __EMSCRIPTEN__ (compiler-provided) and FC_OS_WASM (FreeCAD-defined) — both are defined on wasm. - Built modules today: Part, Sketcher, Material, Start (+ kernel). Everything else is OFF (see BUILD_* in CMakeCache). - PySide/shiboken: FREECAD_USE_PYSIDE=OFF, FREECAD_USE_SHIBOKEN=OFF, PySide6_DIR/Shiboken6_DIR NOTFOUND. Python 'PySide'/'shiboken6' import fails at runtime ("Cannot load shiboken6"). Many workbenches (Draft, BIM, most task dialogs) are Python+PySide and cannot function without it. DELIVERABLES — do BOTH: 1) Write a thorough, concrete, ready-to-apply plan to /home/magik6k/lcad-wasm/porting/<SLUG>/plan.md — include: exact CMake flags/edits, exact source edits (file + before/after or unified-diff snippets precise enough to apply), any NEW files (full contents), external-dependency build recipes (how to build each dep for this emscripten/asyncify toolchain), a threading-hazard list (grep the real files, give file:line + the exact construct + the exact fix), a modal-dialog-hazard list, the PyImport_AppendInittab lines to add, an ordered step list, and an effort/risk estimate. Put any patch files or new-file contents as separate files in that dir too. 2) Return the structured summary (the schema). Keep summary fields concise; the depth goes in plan.md. Your returned text IS the structured object. Be exhaustive and correct — token cost is not a concern. Verify claims against the actual files (use grep/read). If a dependency has no known wasm port, say so plainly and estimate the porting effort. === YOUR SCOPE: Global modal-dialog / nested-event-loop sweep (slug: modal-audit) === Grep src/ (esp. Gui and the candidate Mods: PartDesign, Part, Sketcher, Measure, Import) for QDialog::exec(), ->exec(), QMessageBox::exec()/question()/warning()/critical(), QEventLoop, QProgressDialog, QInputDialog::get*, QFileDialog::get* (file dialogs are a special problem on wasm — they need the async QFileDialog API). List each on an interactive path with file:line and whether it is likely to deadlock under asyncify, plus the async-safe replacement pattern (task panel, or Qt's async QFileDialog::getOpenFileContent). Note FreeCAD's file open/save specifically. Write your full plan + any patch/new-file contents under /home/magik6k/lcad-wasm/porting/modal-audit/ (create the dir; plan.md is required). Then return the structured summary with deliverableFile=/home/magik6k/lcad-wasm/porting/modal-audit/plan.md.
Fable
thinking
I'm going to search through the codebase for modal dialog patterns, focusing on the core modules like Part, Sketcher, Material, and the GUI, along with some additional candidates like PartDesign and Measure.
Fable
⚙ Bash {"command": "git branch --show-current 2>/dev/null; echo \"---\"; ls src/", "description": "Check branch and src layout"}
tool result
wasm-port
---
3rdParty
App
Base
Build
CMakeLists.txt
Doc
Ext
FCConfig.h
FCGlobal.h
Gui
LibraryVersions.h.cmake
MacAppBundle
Main
Mod
QtCore.h.cmake
QtWidgets.h.cmake
SMESH_Version.h.cmake
Tools
XDGData
__init__.py
boost_graph_adjacency_list.hpp
boost_graph_reverse_graph.hpp
boost_regex.hpp
config.h.cmake
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⚙ Bash {"command": "mkdir -p /home/magik6k/lcad-wasm/porting/modal-audit", "description": "Create output dir"}
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⚙ Bash {"command": "grep -c \"FC_OS_WASM\\|__EMSCRIPTEN__\" src/Gui/*.cpp 2>/dev/null | grep -v \":0\" | head -50", "description": "Existing wasm guards in Gui"}
tool result
(Bash completed with no output)
tool result
src/Gui/Application.cpp:2
src/Gui/ProgressBar.cpp:3
src/Gui/View3DInventorViewer.cpp:2
src/Gui/WasmGLWidget.cpp:2
Fable
thinking
I'm going to search through the FreeCAD working directory for relevant patterns to understand the codebase structure.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== QDialog exec (Gui) ===\"; grep -rn \"\\.exec()\\|->exec()\" Gui/ | grep -iv \"process\\|command\\|action\\|menu\\|thread\\|db\\.\\|sql\\|query\" | wc -l\necho \"==…
tool result
=== QDialog exec (Gui) ===
63
=== breakdown by kind across built mods ===
Gui: exec()=89
Mod/Part: exec()=4
Mod/Sketcher: exec()=16
Mod/PartDesign: exec()=18
Mod/Measure: exec()=0
Mod/Import: exec()=2
Mod/Material: exec()=22
Mod/Start: exec()=0
App: exec()=0
Base: exec()=3
Fable
thinking
I need to clarify which modules are actually built versus which are candidates for the task—PartDesign, Import, and Measure aren't currently built, only Part, Sketcher, Material, and Start are. Let me search through the code to find the actual module definitions and check the Gui module since that's critical.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"===== QMessageBox in Gui =====\"\ngrep -rn \"QMessageBox::\" Gui/ | grep -E \"question|warning|critical|information\" | head -80", "description": "QMessageBox static c…
tool result
===== QMessageBox in Gui =====
Gui/Action.cpp:889:        QMessageBox::StandardButton reply = QMessageBox::question(
Gui/Assistant.cpp:96:            QMessageBox::critical(
Gui/Assistant.cpp:133:                        QMessageBox::critical(
Gui/Assistant.cpp:150:                        QMessageBox::critical(
Gui/Assistant.cpp:170:            QMessageBox::critical(
Gui/Command.cpp:518:        QMessageBox::critical(Gui::getMainWindow(), QObject::tr("Exception"), QLatin1String(e.what()));
Gu  …[truncated]
Fable
thinking
I'm realizing the core issue: QMessageBox's static functions like question() and warning() internally call exec(), which spins up a nested event loop. Under Emscripten's asyncify, this creates a deadlock when the dialog is triggered from outside the main event loop. The critical detail is how QDialog::exec() behaves with asyncify's constraints on the main thread.

Actually, Qt 6 for WebAssembly does support QDialog::exec() through asyncify, but the problem manifests specifically when exec() is called from a reentrant path—like FreeCAD's command pump coming through JS→ccall—or when QEventLoop is used to wait on threads that don't exist in the WebAssembly environment. Let me focus on the concr  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"===== QFileDialog getOpen/getSave/getExisting =====\"\ngrep -rn \"QFileDialog::getOpen\\|QFileDialog::getSave\\|QFileDialog::getExisting\\|FileDialog::getOpen\\|FileDi…
tool result
===== QFileDialog getOpen/getSave/getExisting =====
Gui/Command.cpp:133: *     QStringList FileList = QFileDialog::getOpenFileNames( filters, QString(), getMainWindow() );
Gui/CommandDoc.cpp:136:    QStringList fileList = FileDialog::getOpenFileNames(
Gui/CommandDoc.cpp:262:    QStringList fileList = FileDialog::getOpenFileNames(
Gui/CommandDoc.cpp:549:    QString filename = FileDialog::getSaveFileName(
Gui/CommandDoc.cpp:617:    QString project = FileDialog::getOpenFileName(
Gui/CommandDoc  …[truncated]
Fable
thinking
I need to dig into FreeCAD's `Gui::FileDialog` wrapper in FileDialog.cpp — that's where the file dialog logic is centralized. Let me examine how getOpenFileName and getSaveFileName are implemented there and see if there's any existing support for WebAssembly.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"===== wasm guards already in FileDialog =====\"\ngrep -n \"EMSCRIPTEN\\|FC_OS_WASM\\|getOpenFileContent\\|getSaveFileContent\\|saveFileContent\\|wasm\" Gui/FileDialog.…
tool result
===== wasm guards already in FileDialog =====
===== QInputDialog =====
Gui/Dialogs/DlgMacroExecuteImp.cpp:496:    QString fn = QInputDialog::getText(
Gui/Dialogs/DlgMacroExecuteImp.cpp:910:    QString fn = QInputDialog::getText(
Gui/Dialogs/DlgMacroExecuteImp.cpp:1075:    QString fn = QInputDialog::getText(
Gui/Dialogs/DlgParameterImp.cpp:574:    QString name = QInputDialog::getText(
Gui/Dialogs/DlgParameterImp.cpp:810:    QString name = QInputDialog::getText(
Gui/Dialogs/DlgParameterImp.cp  …[truncated]
Fable
thinking
I'm diving into FileDialog.cpp to understand the core file dialog implementations—specifically how getOpenFileName, getSaveFileName, and getOpenFileNames work—and then tracing how FreeCAD wires these into the Std_Open command through CommandDoc.cpp.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Gui/FileDialog.cpp", "offset": 505, "limit": 360}
tool result
505	        if (pat.startsWith("*.")) {
506	            path.append(QStringView(pat).mid(1));
507	            break;
508	        }
509	    }
510	}
511	
512	/**
513	 * This is a convenience static function that will return a file name selected by the user. The file
514	 * does not have to exist.
515	 */
516	QString FileDialog::getSaveFileName(
517	    QWidget* parent,
518	    const QString& caption,
519	    const QString& startPath,
520	    const FilterList& filters,
521	    qsizetype* selectedFi  …[truncated]
Fable
thinking
The real issue is whether FreeCAD's WebAssembly build actually has asyncify enabled in Qt, since dlg.exec() relies on nested event loops that can deadlock without proper support. Qt 6 does support exec() through emscripten_sleep, but only if the build was compiled with the right flags.

The file dialog problem is more fundamental though: WebAssembly has no real filesystem access, so QFileDialog can't work with paths the way FreeCAD expects. The solution is to use Qt's async file methods—getOpenFileContent() to pull bytes from the browser and write them to the in-memory filesystem at a temporary path, then pass that path to FreeCAD's open function. For saving, I'd write to the in-memory files  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"===== Control.cpp (task panel dialog manager) wasm handling =====\"\nsed -n '200,260p' Gui/Control.cpp\necho \"===== showDialog / TaskView =====\"\ngrep -n \"EMSCRIPTE…
tool result
===== Control.cpp (task panel dialog manager) wasm handling =====
    if (!attachedTo) {
        return nullptr;
    }

    Gui::TaskView::TaskView* taskView = taskPanel();

    if (taskView) {
        return taskView->dialog(attachedTo);
    }
    return nullptr;
}

void ControlSingleton::accept(App::Document* attachedTo)
{
    attachedTo = docOrDefault(attachedTo);
    if (!attachedTo) {
        qWarning() << "ControlSingleton::accept: Cannot accept dialog of nullptr document";  …[truncated]
Fable
thinking
I'm tracing through the command execution paths in the codebase, looking at how open/save operations flow through the event loop in DlgPrimitives.h, the 3D viewer implementation, the debugger infrastructure, and the sketcher modules to find all the exec() call sites across the built components.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"===== Part exec() =====\"; grep -rn \"exec()\" Mod/Part/\necho \"===== Sketcher exec() =====\"; grep -rn \"exec()\" Mod/Sketcher/\necho \"===== Material exec() =====\"…
tool result
===== Part exec() =====
Mod/Part/Gui/CommandSimple.cpp:67:    if (dlg.exec() == QDialog::Accepted) {
Mod/Part/Gui/CommandSimple.cpp:126:    dlg.exec();
Mod/Part/Gui/DlgPrimitives.cpp:2267:            int ret = p->loop.exec();
Mod/Part/Gui/TaskFaceAppearances.cpp:506:    dlg.exec();
===== Sketcher exec() =====
Mod/Sketcher/Gui/CommandSketcherTools.cpp:2144:    if (slad.exec() == QDialog::Accepted) {
Mod/Sketcher/Gui/CommandCreateGeo.cpp:1180:    if (srpd.exec() == QDialog::Accepted) {
Mod/Ske  …[truncated]
Fable
thinking
I need to verify whether QDialog::exec() actually functions properly in this asyncify build, since that's the key to determining if these nested event loops will deadlock. Let me examine the emscripten and Qt configuration to see if asyncify is properly set up for handling nested loops, checking the memory settings and CMakeCache for the relevant ASYNCIFY flags.
Fable
⚙ Bash {"command": "cat /home/agent/.claude/projects/-home-magik6k-lcad-wasm/memory/freecad-wasm-viewport.md 2>/dev/null | head -60\necho \"=========== EH/asyncify memory ===========\"\ncat /home/agent/.claude/projects/-home-magik6k-lcad-wasm/memo…
tool result
---
name: freecad-wasm-viewport
description: How the FreeCAD-wasm 3D viewport was made to render (offscreen FBO + QPainter blit) and the asyncify-safe way to create a 3D view
metadata: 
  node_type: memory
  type: project
  originSessionId: 18e25685-98b5-4959-935f-943b1af20789
---

FreeCAD WebAssembly port (/home/magik6k/lcad-wasm/freecad-port/FreeCAD, build dir /opt/toolchains/src/freecad-gui-build). The 3D viewport now RENDERS (gradient background, navigation cube, RGB axis cross all composite  …[truncated]
Fable
thinking
I'm noticing a conflict between what I remember about the toolchain and what the task instructions specify. My memory indicates JSPI is being used with the qt-jspi/6.11.1 setup and wasm exceptions, but the instructions mention ASYNCIFY with JS exceptions instead. I need to verify this against the actual CMakeCache to see which configuration is really in place.
Fable
⚙ Bash {"command": "cd /opt/toolchains/src/freecad-gui-build 2>/dev/null && grep -iE \"ASYNCIFY|JSPI|fwasm-exception|fexception|WASM_LEGACY|Qt6_DIR|QT_DIR|EMSCRIPTEN\" CMakeCache.txt | head -40\necho \"======== link flags in Main ========\"\ngrep …
tool result
CMAKE_CXX_FLAGS:STRING=-fexceptions -DEIGEN_DONT_VECTORIZE -DBOOST_HAS_PTHREADS=1 -DBOOST_STACKTRACE_USE_NOOP
CMAKE_C_FLAGS:STRING=-fexceptions -DXML_DEV_URANDOM
CMAKE_FIND_ROOT_PATH:UNINITIALIZED=/opt/toolchains/qt-asyncify/6.11.1/wasm_singlethread;/opt/toolchains/occt-wasm;/opt/toolchains/xerces-wasm;/opt/toolchains/fmt-wasm;/opt/toolchains/yaml-wasm;/opt/toolchains/python-wasm;/opt/toolchains/boost-wasm;/opt/toolchains/icu-wasm;/opt/toolchains
CMAKE_TOOLCHAIN_FILE:FILEPATH=/opt/toolchains/ems  …[truncated]
Fable
thinking
I need to check the CMakeLists.txt file to see how ASYNCIFY is configured and whether Qt was built with the QT_EMSCRIPTEN_ASYNCIFY flag enabled, since that determines if nested event loops through exec() are supported.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Main/CMakeLists.txt", "offset": 60, "limit": 180}
tool result
60	    freecad_wasm_generate_inittab(${CMAKE_CURRENT_BINARY_DIR}/WasmInittab.cpp
61	        ${FREECAD_WASM_PY_MODULES})
62	    freecad_wasm_generate_inittab(${CMAKE_CURRENT_BINARY_DIR}/WasmInittabGui.cpp
63	        ${FREECAD_WASM_PY_MODULES} ${FREECAD_WASM_PY_GUI_MODULES})
64	
65	    set(FREECAD_WASM_EXTRA_LINK_LIBS "" CACHE STRING
66	        "Extra static archives appended to the FreeCAD wasm links")
67	    set(FREECAD_WASM_COMMON_LINK_OPTIONS
68	        "-sALLOW_MEMORY_GROWTH=1"
69	        "-s  …[truncated]
Fable
thinking
I'm seeing something crucial here—the build configuration explicitly enables asyncify stack switching so that Qt's synchronous `exec()` calls work properly with nested event loops and modal dialogs. This is a deliberate design choice that fundamentally changes how the audit should evaluate the system's capabilities.

The real hazards aren't the modal dialogs themselves, but rather specific edge cases: reentrancy from JavaScript callbacks while asyncify is suspended could corrupt state, QEventLoop waiting on threads or external processes will hang indefinitely since those don't exist in WebAssembly, and file dialogs are completely broken semantically because the MEMFS-based fallback can't acc  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== View3DInventorViewer 4215-4245 ===\"; sed -n '4215,4245p' Gui/View3DInventorViewer.cpp\necho \"=== Widgets.cpp 1240-1258 ===\"; sed -n '1240,1258p' Gui/Widgets.cpp…
tool result
=== View3DInventorViewer 4215-4245 ===
        }
        pos = (box.getCenter() - direction * sphere.getRadius());
    }
    else if (cam->isOfType(SoPerspectiveCamera::getClassTypeId())) {
        // NOLINTBEGIN
        float movelength = sphere.getRadius()
            / float(tan(static_cast<SoPerspectiveCamera*>(cam)->heightAngle.getValue() / 2.0));
        // NOLINTEND
        pos = box.getCenter() - direction * movelength;
    }

    QEventLoop loop;
    QTimer timer;
    timer.setSingleSho  …[truncated]
Fable
thinking
Looking at the QEventLoop sites, I can see that View3DInventorViewer.cpp has a QTimer-driven animation loop for camera operations. Even though animations are disabled on WebAssembly, this particular manual camera animation still works because it relies on QTimer events that fire within the event loop, which means exec() can handle it under asyncify.

StatusWidget::showText in Widgets.cpp is also QTimer-backed and terminates cleanly, so it's low risk despite blocking for the specified duration.

NavigationAnimator::startAndWait is more problematic — it waits for a finished signal from a QAbstractAnimation, but since animation timers are disabled on WebAssembly, that signal may never arrive, c  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== Debugger.h 70-90 ===\"; sed -n '70,95p' Base/Debugger.h\necho \"=== GraphvizView QProcess/exec context ===\"; sed -n '315,395p' Gui/GraphvizView.cpp | grep -n \"ex…
tool result
=== Debugger.h 70-90 ===
    void detach();
    bool eventFilter(QObject* obj, QEvent* event) override;
    int exec();

public Q_SLOTS:
    void quit();

private:
    bool isAttached {false};
    QEventLoop loop;
};

}  // namespace Base
=== GraphvizView QProcess/exec context ===
3:    dotProc->setEnvironment(QProcess::systemEnvironment());
4:    flatProc->setEnvironment(QProcess::systemEnvironment());
6:        flatProc->start(unflatten, flatArgs);
9:        dotProc->start(dot, args);
=== Edit  …[truncated]
Fable
thinking
The BUILD_TEST flag disables CommandTest.cpp compilation, so GraphvizView remains part of the GUI but only gets invoked through the "Dependency graph" command, which relies on the `dot` subprocess that won't work on WebAssembly since QProcess isn't available there—though this isn't a critical interactive path. EditDatumDialog::exec() handles the dimensional constraint editing in the classic Sketcher workflow as a modal dialog, and under asyncify it should function properly when entered from the main event loop.

Now I'm checking the file open/save flow to understand how FreeCAD handles this, particularly the FileDialog execution path and whether DontUseNativeFileDialog is enabled by default.  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== nativeFileDialog impl ===\"; grep -n \"nativeFileDialog\\|dontUseNativeFileDialog\\|getOpenFileContent\\|QFileDialog::getOpenFileName\\b\" Gui/FileDialog.cpp | hea…
tool result
=== nativeFileDialog impl ===
144:bool DialogOptions::dontUseNativeFileDialog()
377:QStringList FileDialogInternal::nativeFileDialog(
392:        selected << QFileDialog::getOpenFileName(
430:            "Qt-backed nativeFileDialog returned a selected filter that wasn't in the original "
564:    if (DialogOptions::dontUseNativeFileDialog()) {
608:        const auto files = nativeFileDialog(
702:    if (DialogOptions::dontUseNativeFileDialog()) {
739:        const auto files = nativeFileDi  …[truncated]
Fable
thinking
I'm tracing through how file dialogs work on WebAssembly with Qt — specifically whether Qt for wasm's native file dialog actually uses the browser's file picker or if it has limitations in its platform integration.

The core issue is that `QFileDialog::getOpenFileName` is a blocking call that returns a path, but the browser's file picker is inherently asynchronous. Qt bridges this gap using asyncify, which suspends execution while waiting for the async JavaScript file input to resolve. Historically Qt recommended using `getOpenFileContent` for wasm because the static blocking functions didn't work, but with asyncify support in Qt 6.11, they might now be functional.

However, looking at the c  …
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== dontUseNativeFileDialog default ===\"; sed -n '144,175p' Gui/FileDialog.cpp\necho \"=== CommandDoc open (Std_Open) context 120-160 ===\"; sed -n '120,160p' Gui/Com…
tool result
=== dontUseNativeFileDialog default ===
bool DialogOptions::dontUseNativeFileDialog()
{
#if defined(USE_QT_DIALOGS)
    constexpr bool notNativeDialog = true;
#else
    constexpr bool notNativeDialog = false;
#endif

    ParameterGrp::handle group = App::GetApplication()
                                     .GetUserParameter()
                                     .GetGroup("BaseApp")
                                     ->GetGroup("Preferences")
                                     -  …[truncated]
Fable
thinking
So USE_QT_DIALOGS isn't defined, which means dontUseNativeFileDialog defaults to false and takes the native file dialog path—specifically QFileDialog::getOpenFileName on Qt-wasm, which triggers the browser file picker. The real question is whether that path reliably returns a usable file path. I should do a final search to make sure I'm covering QColorDialog, QFontDialog, and the print dialog as well when I write out the full plan.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\necho \"=== color/font/print dialogs ===\"; grep -rn \"QColorDialog::getColor\\|QFontDialog::getFont\\|QPrintDialog\\|QPageSetupDialog\\|->exec()\" Gui/ | grep -iE \"color|fon…
tool result
=== color/font/print dialogs ===
Gui/EditorView.cpp:33:#include <QPrintDialog>
Gui/EditorView.cpp:483:    QPrintDialog dlg(&printer, this);
Gui/ImageView.cpp:38:#include <QPrintDialog>
Gui/GraphvizView.cpp:32:#include <QPrintDialog>
Gui/GraphvizView.cpp:599:    QPrintDialog dlg(&printer, this);
Gui/MDIView.cpp:30:#include <QPrintDialog>
Gui/MDIView.cpp:275:    QPrintDialog dlg(&printer, this);
Gui/QtAll.h:121:#include <QPrintDialog>
Gui/View3DInventor.cpp:36:#include <QPrintDialog>
Gui/Vie  …[truncated]
Fable
thinking
I'm noting that print dialogs aren't viable on WebAssembly since there's no printer access, but they're behind a print command so they're not critical to the core functionality. Now I'm ready to write out the plan document with a comprehensive structure, starting with an executive summary that highlights the key finding about Qt being built with asyncify enabled, which means modal dialogs like exec() actually work properly from the main event loop.
Fable
Now I have enough grounding. Let me write the plan and supporting files.
Fable
⚙ Write {"file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/plan.md", "content": "# Modal-dialog / nested-event-loop audit — FreeCAD wasm port\n\nSlug: `modal-audit`\nScope: global sweep of `src/` (esp. `Gui/` and candidate Mods Part, Sketch…
tool result
File created successfully at: /home/magik6k/lcad-wasm/porting/modal-audit/plan.md (file state is current in your context — no need to Read it back)
Fable
Now the supporting patch/new-file contents.
Fable
⚙ Write {"file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/WasmFileBridge.h", "content": "// SPDX-License-Identifier: LGPL-2.1-or-later\n// FreeCAD wasm port: browser <-> MEMFS file bridge for Gui::FileDialog.\n// Only compiled on __EMSCRIP…
tool result
File created successfully at: /home/magik6k/lcad-wasm/porting/modal-audit/WasmFileBridge.h (file state is current in your context — no need to Read it back)
Fable
⚙ Write {"file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/WasmFileBridge.cpp", "content": "// SPDX-License-Identifier: LGPL-2.1-or-later\n// FreeCAD wasm port: browser <-> MEMFS file bridge for Gui::FileDialog.\n#ifdef FC_OS_WASM\n\n#inclu…
tool result
File created successfully at: /home/magik6k/lcad-wasm/porting/modal-audit/WasmFileBridge.cpp (file state is current in your context — no need to Read it back)
Fable
thinking
Now I'm working on the FileDialog patch, creating a unified diff that adds the wasm branches alongside the existing function signatures and includes.
Fable
⚙ Write {"file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/filedialog-wasm.patch", "content": "--- a/src/Gui/FileDialog.cpp\n+++ b/src/Gui/FileDialog.cpp\n@@ -- includes (top of file, after the existing Qt includes) --\n+#ifdef FC_OS_WASM\n…
tool result
File created successfully at: /home/magik6k/lcad-wasm/porting/modal-audit/filedialog-wasm.patch (file state is current in your context — no need to Read it back)
Fable
thinking
Working through the classB-guards.patch now, referencing the specific functions like NavigationAnimator::startAndWait, the View3DInventorViewer camera loop around line 4225, and GraphvizView's command handler to write appropriate guard conditions. I'll also incorporate the Application.cpp flush pump note and the Gui/CMakeLists modification, keeping everything formatted as a proper patch file.

For the View3DInventorViewer camera animation, I'm placing the guard right before the event loop initialization—it'll compute the final camera pose and height from the loop's last iteration values, then return early with those final settings applied rather than running the full animation sequence.
Fable
⚙ Write {"file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/classB-guards.patch", "content": "Class-B hard-hang guards (see plan.md §2). These QEventLoops wait on signals that\nnever fire on single-threaded / no-subprocess / animation-disabl…
tool result
File created successfully at: /home/magik6k/lcad-wasm/porting/modal-audit/classB-guards.patch (file state is current in your context — no need to Read it back)
Fable
thinking
I'm checking whether the Application.cpp flush pump wiring note and Gui/CMakeLists EMSCRIPTEN target_sources are already covered in the plan, since they're referenced in the requirements.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src\ngrep -n \"WasmGLWidget\\|EMSCRIPTEN\\|target_sources\" Gui/CMakeLists.txt | head\necho \"=== fc-cmd pump location in Application.cpp ===\"\ngrep -n \"fc-cmd\\|EMSCRIPTEN\\|si…
tool result
1501:target_sources(FreeCADGui PRIVATE ${FreeCADGui_SRCS})
1571:if(EMSCRIPTEN)
1574:    target_sources(FreeCADGui PRIVATE FcWasmProcess.cpp WasmGLFixedFunc.cpp WasmGLWidget.cpp)
=== fc-cmd pump location in Application.cpp ===
42:#include <QTimer>
1171:        QTimer::singleShot(0, [candidates]() {
2731:    QTimer::singleShot(0, &mw, SLOT(delayedStartup()));
2733:#ifdef __EMSCRIPTEN__
2749:    QTimer::singleShot(300, []() {
2765:    // snippet to /fc-cmd.py; this repeating timer, firing on the ev  …[truncated]
Fable
thinking
I've confirmed the EMSCRIPTEN target_sources line in the CMakeLists.txt file, so I need to update the plan to reference the correct source files—FcWasmProcess.cpp, WasmGLFixedFunc.cpp, and WasmGLWidget.cpp—plus add WasmFileBridge.cpp. I also found the command pump location at Application.cpp:2768, so I'll revise both the CMake and pump references in the plan.
Fable
⚙ Edit {"replace_all": false, "file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/plan.md", "old_string": "`src/Gui/CMakeLists.txt` — add to the `if(EMSCRIPTEN) target_sources(...)` block that already\nlists `WasmGLWidget.cpp` (per viewport …
tool result
The file /home/magik6k/lcad-wasm/porting/modal-audit/plan.md has been updated successfully. (file state is current in your context — no need to Read it back)
Fable
⚙ Edit {"replace_all": false, "file_path": "/home/magik6k/lcad-wasm/porting/modal-audit/plan.md", "old_string": " - Arm the save-flush QTimer in `Gui/Application.cpp` runApplication next to the existing\n `/fc-cmd.py` pump (or self-contained…
tool result
The file /home/magik6k/lcad-wasm/porting/modal-audit/plan.md has been updated successfully. (file state is current in your context — no need to Read it back)
Fable
All deliverables are written. Let me return the structured summary.
Fable
⚙ StructuredOutput {"slug": "modal-audit", "title": "Global modal-dialog / nested-event-loop audit", "feasibility": "needs-code", "oneLineVerdict": "Synchronous modal exec() already works (Qt built QT_EMSCRIPTEN_ASYNCIFY=1, app linked -sASYNCIFY); the real ha…
tool result
Structured output provided successfully