HackStudio: Show local variables in the debugger

We now have a Debug Information tab, which displays the variables in
the current scope in a tree view.

DevTools/HackStudio/DebugInfoWidget.cpp

@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "DebugInfoWidget.h"
+#include "Debugger.h"
+#include <AK/StringBuilder.h>
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/Model.h>
+#include <LibGUI/TreeView.h>
+
+GUI::ModelIndex DebugInfoModel::index(int row, int column, const GUI::ModelIndex& parent_index) const
+{
+    if (!parent_index.is_valid())
+        return create_index(row, column, &m_variables[row]);
+    auto* parent = static_cast<const DebugInfo::VariableInfo*>(parent_index.internal_data());
+    auto* child = &parent->members[row];
+    return create_index(row, column, child);
+}
+
+GUI::ModelIndex DebugInfoModel::parent_index(const GUI::ModelIndex& index) const
+{
+    if (!index.is_valid())
+        return {};
+    auto* child = static_cast<const DebugInfo::VariableInfo*>(index.internal_data());
+    auto* parent = child->parent;
+    if (parent == nullptr)
+        return {};
+
+    if (parent->parent == nullptr) {
+        for (size_t row = 0; row < m_variables.size(); row++)
+            if (m_variables.ptr_at(row).ptr() == parent)
+                return create_index(row, 0, parent);
+        ASSERT_NOT_REACHED();
+    }
+    for (size_t row = 0; row < parent->parent->members.size(); row++) {
+        DebugInfo::VariableInfo* child_at_row = parent->parent->members.ptr_at(row).ptr();
+        if (child_at_row == parent)
+            return create_index(row, 0, parent);
+    }
+    ASSERT_NOT_REACHED();
+}
+
+int DebugInfoModel::row_count(const GUI::ModelIndex& index) const
+{
+    if (!index.is_valid())
+        return m_variables.size();
+    auto* node = static_cast<const DebugInfo::VariableInfo*>(index.internal_data());
+    return node->members.size();
+}
+
+String variable_value_as_string(const DebugInfo::VariableInfo& variable)
+{
+    if (variable.location_type != DebugInfo::VariableInfo::LocationType::Address)
+        return "N/A";
+
+    auto variable_address = variable.location_data.address;
+
+    if (variable.type == "int") {
+        auto value = Debugger::the().session()->peek((u32*)variable_address);
+        ASSERT(value.has_value());
+        return String::format("%d", static_cast<int>(value.value()));
+    }
+
+    if (variable.type == "char") {
+        auto value = Debugger::the().session()->peek((u32*)variable_address);
+        ASSERT(value.has_value());
+        return String::format("'%c' (%d)", static_cast<char>(value.value()), static_cast<char>(value.value()));
+    }
+
+    return String::format("address: %08x, ", variable_address);
+}
+
+GUI::Variant DebugInfoModel::data(const GUI::ModelIndex& index, Role role) const
+{
+    auto* variable = static_cast<const DebugInfo::VariableInfo*>(index.internal_data());
+    switch (role) {
+    case Role::Display: {
+        auto value_as_string = variable_value_as_string(*variable);
+        return String::format("%s: %s", variable->name.characters(), value_as_string.characters());
+    }
+    case Role::Icon:
+        return m_variable_icon;
+    default:
+        return {};
+    }
+}
+
+void DebugInfoModel::update()
+{
+    did_update();
+}
+
+static RefPtr<DebugInfoModel> create_model(const PtraceRegisters& regs)
+{
+    auto variables = Debugger::the().session()->debug_info().get_variables_in_current_scope(regs);
+    return adopt(*new DebugInfoModel(move(variables), regs));
+}
+
+DebugInfoWidget::DebugInfoWidget()
+{
+    set_layout<GUI::VerticalBoxLayout>();
+    m_info_view = add<GUI::TreeView>();
+}
+
+void DebugInfoWidget::update_variables(const PtraceRegisters& regs)
+{
+    auto model = create_model(regs);
+    m_info_view->set_model(model);
+}

DevTools/HackStudio/DebugInfoWidget.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Debugger.h"
+#include <AK/NonnullOwnPtr.h>
+#include <LibGUI/Model.h>
+#include <LibGUI/Widget.h>
+#include <sys/arch/i386/regs.h>
+
+class DebugInfoModel final : public GUI::Model {
+public:
+    explicit DebugInfoModel(NonnullOwnPtrVector<DebugInfo::VariableInfo>&& variables, const PtraceRegisters& regs)
+        : m_variables(move(variables))
+        , m_regs(regs)
+    {
+        m_variable_icon.set_bitmap_for_size(16, Gfx::Bitmap::load_from_file("/res/icons/16x16/inspector-object.png"));
+    }
+
+    virtual int row_count(const GUI::ModelIndex& = GUI::ModelIndex()) const override;
+    virtual int column_count(const GUI::ModelIndex& = GUI::ModelIndex()) const override { return 1; }
+    virtual GUI::Variant data(const GUI::ModelIndex& index, Role role = Role::Display) const override;
+    virtual void update() override;
+    virtual GUI::ModelIndex parent_index(const GUI::ModelIndex&) const override;
+    virtual GUI::ModelIndex index(int row, int column = 0, const GUI::ModelIndex& = GUI::ModelIndex()) const override;
+
+private:
+    NonnullOwnPtrVector<DebugInfo::VariableInfo> m_variables;
+    PtraceRegisters m_regs;
+
+    GUI::Icon m_variable_icon;
+};
+
+class DebugInfoWidget final : public GUI::Widget {
+    C_OBJECT(DebugInfoWidget)
+public:
+    virtual ~DebugInfoWidget() override {}
+
+    void update_variables(const PtraceRegisters&);
+
+private:
+    explicit DebugInfoWidget();
+
+    RefPtr<GUI::TreeView> m_info_view;
+};

DevTools/HackStudio/Debugger.cpp

@@ -35,7 +35,7 @@ Debugger& Debugger::the()
 }
 
 void Debugger::initialize(
-    Function<void(DebugInfo::SourcePosition)> on_stop_callback,
+    Function<void(const PtraceRegisters&)> on_stop_callback,
     Function<void()> on_continue_callback,
     Function<void()> on_exit_callback)
 {
@@ -48,7 +48,7 @@ bool Debugger::is_initialized()
 }
 
 Debugger::Debugger(
-    Function<void(DebugInfo::SourcePosition)> on_stop_callback,
+    Function<void(const PtraceRegisters&)> on_stop_callback,
     Function<void()> on_continue_callback,
     Function<void()> on_exit_callback)
     : m_on_stopped_callback(move(on_stop_callback))
@@ -129,10 +129,6 @@ int Debugger::debugger_loop()
         }
         ASSERT(optional_regs.has_value());
         const PtraceRegisters& regs = optional_regs.value();
-        auto source_position = m_debug_session->debug_info().get_source_position(regs.eip);
-        if (!source_position.has_value()) {
-            return DebugSession::DebugDecision::Continue;
-        }
 
         if (in_single_step_mode) {
             for (auto address : temporary_breakpoints) {
@@ -142,8 +138,7 @@ int Debugger::debugger_loop()
             in_single_step_mode = false;
         }
 
-        dbg() << "Debugee stopped @ " << source_position.value().file_path << ":" << source_position.value().line_number;
-        m_on_stopped_callback(source_position.value());
+        m_on_stopped_callback(regs);
 
         pthread_mutex_lock(&m_continue_mutex);
         pthread_cond_wait(&m_continue_cond, &m_continue_mutex);

DevTools/HackStudio/Debugger.h

@@ -26,6 +26,7 @@
  */
 
 #pragma once
+
 #include "BreakpointCallback.h"
 #include <AK/Function.h>
 #include <AK/Vector.h>
@@ -37,7 +38,7 @@ class Debugger {
 public:
     static Debugger& the();
     static void initialize(
-        Function<void(DebugInfo::SourcePosition)> on_stop_callback,
+        Function<void(const PtraceRegisters&)> on_stop_callback,
         Function<void()> on_continue_callback,
         Function<void()> on_exit_callback);
 
@@ -65,7 +66,7 @@ public:
 
 private:
     explicit Debugger(
-        Function<void(DebugInfo::SourcePosition)> on_stop_callback,
+        Function<void(const PtraceRegisters&)> on_stop_callback,
         Function<void()> on_continue_callback,
         Function<void()> on_exit_callback);
 
@@ -82,7 +83,7 @@ private:
     Vector<DebugInfo::SourcePosition> m_breakpoints;
     String m_executable_path;
 
-    Function<void(DebugInfo::SourcePosition)> m_on_stopped_callback;
+    Function<void(const PtraceRegisters&)> m_on_stopped_callback;
     Function<void()> m_on_continue_callback;
     Function<void()> m_on_exit_callback;
 

DevTools/HackStudio/Makefile

@@ -6,6 +6,7 @@ OBJS = \
     ProcessStateWidget.o \
     FormEditorWidget.o \
     FormWidget.o \
+    DebugInfoWidget.o \
     Editor.o \
     EditorWrapper.o \
     Locator.o \

DevTools/HackStudio/main.cpp

@@ -25,6 +25,7 @@
  */
 
 #include "CursorTool.h"
+#include "DebugInfoWidget.h"
 #include "Debugger.h"
 #include "Editor.h"
 #include "EditorWrapper.h"
@@ -508,6 +509,7 @@ int main(int argc, char** argv)
 
     auto& find_in_files_widget = s_action_tab_widget->add_tab<FindInFilesWidget>("Find in files");
     auto& terminal_wrapper = s_action_tab_widget->add_tab<TerminalWrapper>("Build", false);
+    auto& debug_info_widget = s_action_tab_widget->add_tab<DebugInfoWidget>("Debug");
 
     auto& locator = widget.add<Locator>();
 
@@ -602,12 +604,17 @@ int main(int argc, char** argv)
 
     RefPtr<EditorWrapper> current_editor_in_execution;
     Debugger::initialize(
-        [&](DebugInfo::SourcePosition source_position) {
+        [&](const PtraceRegisters& regs) {
             dbg() << "Program stopped";
-            current_editor_in_execution = get_editor_of_file(source_position.file_path);
-            current_editor_in_execution->editor().set_execution_position(source_position.line_number - 1);
+
+            auto source_position = Debugger::the().session()->debug_info().get_source_position(regs.eip);
+            ASSERT(source_position.has_value());
+            current_editor_in_execution = get_editor_of_file(source_position.value().file_path);
+            current_editor_in_execution->editor().set_execution_position(source_position.value().line_number - 1);
+            debug_info_widget.update_variables(regs);
             continue_action->set_enabled(true);
             single_step_action->set_enabled(true);
+            reveal_action_tab(debug_info_widget);
         },
         [&]() {
             dbg() << "Program continued";