fix(furdb): improve printing

furdb/include/command.hpp

@@ -36,4 +36,24 @@ public:
     void execute(context& ctx, const command_info& info) override;
 };
 
+class continue_command final : public command {
+public:
+    void execute(context& ctx, const command_info& info) override;
+};
+
+class next_command final : public command {
+public:
+    void execute(context& ctx, const command_info& info) override;
+};
+
+class break_command final : public command {
+public:
+    void execute(context& ctx, const command_info& info) override;
+};
+
+class info_command final : public command {
+public:
+    void execute(context& ctx, const command_info& info) override;
+};
+
 #endif // COMMAND_HPP

furdb/include/context.hpp

@@ -13,8 +13,14 @@ struct context {
     furvm::function_h mainFunction;
 
     bool running = true;
+    bool halt    = true;
+
+    void kill() const;
+    void init();
 
     void run();
+
+    void print_instruction() const;
 };
 
 #endif // CONTEXT_HPP

furdb/src/command.cpp

@@ -1,9 +1,16 @@
 #include "command.hpp"
 
+#include "furvm/executor.hpp"
+#include "furvm/function.hpp"
+#include "furvm/instruction.hpp"
+#include "furvm/module.hpp"
+#include "furvm/thing.hpp"
+
 #include <cctype>
 #include <cstddef>
 #include <iostream>
 #include <random>
+#include <string>
 #include <utility>
 
 command_info command::parse(std::string_view line) {
@@ -50,6 +57,135 @@ void quit_command::execute(context& ctx, const command_info& info) {
 }
 
 void run_command::execute(context& ctx, const command_info& info) {
-    ctx.run();
-    std::cout << "Execution finished\n";
+    if (!ctx.executor->done()) {
+        std::cout << "A program is currently running, do you want to kill it? (y/N) ";
+        std::string answer;
+        if (!std::getline(std::cin, answer)) {
+            ctx.running = false;
+            return;
+        }
+        if (answer != "y" && answer != "Y" && answer != "yes") return;
+        ctx.kill();
+    }
+    std::cout << "Running the program\n";
+    ctx.run();
+}
+
+void continue_command::execute(context& ctx, const command_info& info) {
+    ctx.run();
+}
+
+void next_command::execute(context& ctx, const command_info& info) {
+    if (ctx.executor->done()) {
+        std::cout << "No program's currently running\n";
+        return;
+    }
+    ctx.executor->unsuspend();
+    ctx.executor->step();
+    ctx.print_instruction();
+}
+
+static void print_type(const furvm::thing_type& type) {
+    switch (type.type) {
+    case furvm::thing_type::S8: std::cout << "s8"; break;
+    case furvm::thing_type::S16: std::cout << "s16"; break;
+    case furvm::thing_type::S32: std::cout << "s32"; break;
+    case furvm::thing_type::S64: std::cout << "s64"; break;
+    case furvm::thing_type::U8: std::cout << "u8"; break;
+    case furvm::thing_type::U16: std::cout << "u16"; break;
+    case furvm::thing_type::U32: std::cout << "u32"; break;
+    case furvm::thing_type::U64: std::cout << "u64"; break;
+    case furvm::thing_type::Ptr: std::cout << "ptr"; break;
+    case furvm::thing_type::Ref: std::cout << "ref"; break;
+    case furvm::thing_type::Array:
+        std::cout << "array(";
+        print_type(*type.value.array.type);
+        std::cout << ", ";
+        if (type.value.array.size == 0)
+            std::cout << "dynamic";
+        else
+            std::cout << type.value.array.size;
+        std::cout << ")";
+        break;
+    case furvm::thing_type::Count: break;
+    }
+}
+
+static void print_thing(const furvm::thing<>& thing) {
+    std::cout << '(';
+    print_type(thing.type());
+    std::cout << ") ";
+    switch (thing.type().type) {
+    case furvm::thing_type::S8: std::cout << std::to_string(thing.get<furvm::thing_type::s8>()); break;
+    case furvm::thing_type::S16: std::cout << thing.get<furvm::thing_type::s16>(); break;
+    case furvm::thing_type::S32: std::cout << thing.get<furvm::thing_type::s32>(); break;
+    case furvm::thing_type::S64: std::cout << thing.get<furvm::thing_type::s64>(); break;
+    case furvm::thing_type::U8: std::cout << std::to_string(thing.get<furvm::thing_type::u8>()); break;
+    case furvm::thing_type::U16: std::cout << thing.get<furvm::thing_type::u16>(); break;
+    case furvm::thing_type::U32: std::cout << thing.get<furvm::thing_type::u32>(); break;
+    case furvm::thing_type::U64: std::cout << thing.get<furvm::thing_type::u64>(); break;
+    case furvm::thing_type::Ptr: std::cout << thing.get<const void*>(); break;
+    case furvm::thing_type::Array: {
+        if (thing.type().value.array.size == 0) std::cout << thing.length();
+        std::cout << "{ ";
+        for (std::size_t i = 0; i < thing.length(); ++i) {
+            if (i > 0) std::cout << ", ";
+            print_thing(thing.at(i));
+        }
+        std::cout << " }";
+    } break;
+    case furvm::thing_type::Ref:
+    case furvm::thing_type::Count: break;
+    }
+}
+
+static void breakpoint_hit(furvm::executor& executor, void* data) {
+    std::cout << "Breakpoint hit\n";
+    context* ctx = reinterpret_cast<context*>(data);
+    ctx->halt    = true;
+
+    ctx->print_instruction();
+}
+
+void break_command::execute(context& ctx, const command_info& info) {
+    if (info.args.empty()) {
+        std::cerr << "Usage: " << info.commandName << " <function name>\n";
+        return;
+    }
+
+    std::size_t count = 0;
+    for (const auto& [id, sigPair] : ctx.mod->function_map()) {
+        if (sigPair.first != info.args[0]) continue;
+        const auto& func = ctx.mod->function_at(id);
+        if (func->type() != furvm::function_t::Normal) continue;
+        count += 1;
+        ctx.mod->set_breakpoint(func->position(), furvm::breakpoint{ breakpoint_hit, &ctx });
+    }
+    if (count == 0) {
+        std::cerr << "No function \"" << info.args[0] << "\" found!\n";
+        return;
+    }
+    std::cout << "Breakpoint set in " << count << " places\n";
+}
+
+void info_command::execute(context& ctx, const command_info& info) {
+    if (info.args.empty()) {
+        std::cout << "Possible arguments:\n";
+        std::cout << "- variables\n";
+    } else if (info.args[0] == "variables") {
+        if (ctx.executor->frames().empty()) {
+            std::cerr << "Not running\n";
+            return;
+        }
+        std::cout << "Variables:\n";
+        const auto& frame = ctx.executor->top_frame();
+        for (std::size_t i = 0; i < frame.variables.size(); ++i) {
+            // TODO: Add debug information to modules
+            std::cout << "- %" << i << " = ";
+            print_thing(frame.variables[i]);
+            std::cout << '\n';
+        }
+    } else {
+        std::cerr << "Unexpected argument \"" << info.args[0] << "\"\n";
+    }
 }

furdb/src/context.cpp

@@ -1,9 +1,135 @@
 #include "context.hpp"
 
-void context::run() {
-    if ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done)
+#include <furvm/executor.hpp>
+#include <furvm/instruction.hpp>
+#include <iostream>
+#include <stdexcept>
+
+void context::kill() const {
+    while (!executor->done())
+        executor->pop_frame();
+}
+
+void context::init() {
+    kill();
     executor->push_frame(mod, *mainFunction);
-    while ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done) {
+    executor->clear_flags();
+}
+
+void context::run() {
+    if (executor->done()) init();
+    executor->unsuspend();
+
+    halt = false;
+    while (!executor->done() && !halt)
         executor->step();
+    if (executor->done()) {
+        std::cout << "Execution finished\n";
+        halt = true;
     }
 }
+
+void context::print_instruction() const {
+    static const char* s_instrNames[furvm::instruction::Count] = {
+        // NoOperation
+        "nop",
+        // PushS8
+        "push $s8",
+        // PushU8
+        "push $u8",
+        // PushS16
+        "push $s16",
+        // PushU16
+        "push $U16",
+        // PushS32
+        "push $S32",
+        // PushU32
+        "push $U32",
+        // PushConstant
+        "push",
+        // Array
+        "array",
+        // Get
+        "get",
+        // Set
+        "set",
+        // Drop
+        "drop",
+        // Duplicate
+        "dup",
+        // Swap
+        "swap",
+        // Clone
+        "clone",
+        // Reference
+        "ref",
+        // Add
+        "add",
+        // Sub
+        "sub",
+        // Mul
+        "mul",
+        // Div
+        "div",
+        // Mod
+        "mod",
+        // Equals
+        "eq",
+        // NotEquals
+        "ne",
+        // LessThan
+        "lt",
+        // GreaterThan
+        "gt",
+        // LessEqual
+        "le",
+        // GreaterEqual
+        "ge",
+        // Pointerof
+        "pointerof",
+        // Sizeof
+        "sizeof",
+        // Lengthof
+        "lenof",
+        // Load
+        "load",
+        // Store
+        "store",
+        // LoadGlobal
+        "loadg",
+        // StoreGlobal
+        "storeg",
+        // Call
+        "call",
+        // Jump
+        "jmp",
+        // JumpNotZero
+        "jnz",
+        // Return
+        "ret",
+    };
+
+    furvm::instruction instr{};
+    instr.read(mod->bytecode_view().subview(executor->top_frame().position));
+    std::cout << s_instrNames[instr.type];
+    if (instr.arg.type != furvm::instruction_argument_t::None) {
+        std::cout << ' ';
+        switch (instr.arg.type) {
+        case furvm::instruction_argument::S8: std::cout << std::to_string(instr.arg.s8); break;
+        case furvm::instruction_argument::U8: std::cout << std::to_string(instr.arg.u8); break;
+        case furvm::instruction_argument::S16: std::cout << instr.arg.s16; break;
+        case furvm::instruction_argument::U16: std::cout << instr.arg.u16; break;
+        case furvm::instruction_argument::S32: std::cout << instr.arg.s32; break;
+        case furvm::instruction_argument::U32: std::cout << instr.arg.u32; break;
+        case furvm::instruction_argument::None:
+        case furvm::instruction_argument::Count: break;
+        case furvm::instruction_argument::Constant: throw std::runtime_error("unimplemented");
+        case furvm::instruction_argument::Type: std::cout << "$__t" << instr.arg.u32; break;
+        case furvm::instruction_argument::Variable: std::cout << "%" << instr.arg.u16; break;
+        case furvm::instruction_argument::GlobalVariable: std::cout << "%__g" << instr.arg.u16; break;
+        case furvm::instruction_argument::Function: std::cout << "<a function>"; break;
+        case furvm::instruction_argument::Offset: std::cout << std::to_string(instr.arg.s8); break;
+        }
+    }
+    std::cout << '\n';
+}

furdb/src/main.cpp

@@ -43,8 +43,12 @@ int main(int argc, char** argv) {
     }
 
     static std::unordered_map<std::string_view, command*> s_commands;
-    s_commands["quit"] = s_commands["q"] = new quit_command();
+    s_commands["exit"] = s_commands["quit"] = s_commands["q"] = new quit_command();
     s_commands["run"] = s_commands["r"] = new run_command();
+    s_commands["continue"] = s_commands["c"] = new continue_command();
+    s_commands["next"] = s_commands["n"] = new next_command();
+    s_commands["break"] = s_commands["b"] = new break_command();
+    s_commands["info"] = s_commands["i"] = new info_command();
 
     try {
         std::ifstream file(argv[1], std::ios::binary | std::ios::in);

furvm/include/furvm/executor.hpp

@@ -7,7 +7,6 @@
 
 #include <functional>
 #include <stack>
-#include <utility>
 #include <vector>
 
 namespace furvm {
@@ -15,6 +14,8 @@ namespace furvm {
 enum class executor_flags : std::uint32_t {
     Suspended = (1 << 0), /**< Execution suspended. */
     Done      = (1 << 1), /**< Execution is finished. */
+
+    JustHit = (1 << 16), /**< Executor just hit a breakpoint. */
 };
 
 static inline executor_flags operator|(executor_flags lhs, executor_flags rhs) {
@@ -29,13 +30,15 @@ static inline executor_flags operator~(executor_flags flags) {
     return executor_flags(~static_cast<std::uint32_t>(flags));
 }
 
-using executor_callback = std::function<void(executor&)>;
-
 class executor {
     friend class context;
 private:
     executor(context* context)
       : m_context(context) {}
+public:
+    static constexpr executor_flags STATE_FLAGS = executor_flags::JustHit;
+
+    using new_frame_callback = std::function<void(executor&)>;
 public:
     /**
      * @brief Executor frame.
@@ -84,6 +87,17 @@ public:
      * @return The flags.
      */
     executor_flags flags() const { return m_flags; }
+
+    bool done() const { return (m_flags & executor_flags::Done) == executor_flags::Done; }
+
+    bool suspended() const { return (m_flags & executor_flags::Suspended) == executor_flags::Suspended; }
+
+    void unsuspend() { m_flags = m_flags & ~executor_flags::Suspended; }
+
+    void clear_flags() {
+        m_flags = m_flags & STATE_FLAGS;
+        m_flags = m_frames.empty() ? executor_flags::Done : furvm::executor_flags{ 0 };
+    }
 public:
     /**
      * @brief Pushes a new frame.
@@ -174,13 +188,13 @@ private:
 private:
     static bool compare_thing_types(const thing_type& lhs, const thing_type& rhs);
 private:
-    executor_flags m_flags{}; // NOLINT(bugprone-invalid-enum-default-initialization)
+    executor_flags m_flags = executor_flags::Done;
     context*       m_context;
 
     std::stack<frame>   m_frames;
     std::stack<thing<>> m_stack;
 
-    executor_callback m_newFrameCb = nullptr;
+    new_frame_callback m_newFrameCb = nullptr;
 };
 
 } // namespace furvm

furvm/include/furvm/module.hpp

@@ -145,6 +145,11 @@ struct mod_type {
     }
 };
 
+struct breakpoint {
+    std::function<void(executor&, void*)> callback;
+    void*                                 data = nullptr;
+};
+
 class mod {
     friend class function;
     friend class serializer;
@@ -379,6 +384,15 @@ public:
         if (var >= m_globalVariables.size()) throw std::runtime_error("invalid slot");
         return m_globalVariables[var];
     }
+public:
+    template <typename Fwd, typename = std::enable_if_t<std::is_constructible_v<breakpoint, Fwd>>>
+    void set_breakpoint(bytecode_pos pos, Fwd&& breakpoint) {
+        m_breakpoints[pos] = std::forward<Fwd>(breakpoint);
+    }
+
+    bool has_breakpoint(bytecode_pos pos) const { return m_breakpoints.find(pos) != m_breakpoints.end(); }
+
+    const breakpoint& breakpoint_at(bytecode_pos pos) const { return m_breakpoints.at(pos); }
 public:
     /**
      * @brief Prints the module in a bytecode form to an output stream.
@@ -410,6 +424,8 @@ private:
     std::vector<thing<>> m_globalVariables;
 
     std::unordered_map<std::string, native_function> m_nativeFunctions;
+
+    std::unordered_map<bytecode_pos, breakpoint> m_breakpoints;
 };
 
 } // namespace furvm

furvm/src/executor.cpp

@@ -104,6 +104,13 @@ void executor::push_frame(const mod_h& mod, function function) {
     default: throw std::runtime_error("unexpected function type");
     }
     if (m_newFrameCb) m_newFrameCb(*this);
+
+    if (!m_frames.empty()) {
+        m_flags = m_flags & ~executor_flags::Done;
+    } else {
+        m_flags = m_flags | executor_flags::Done;
+    }
+    m_flags = m_flags & ~executor_flags::JustHit;
 }
 
 struct executor::frame executor::pop_frame() {
@@ -117,6 +124,14 @@ struct executor::frame executor::pop_frame() {
     }
     if (m_stack.size() != frame.stackBase) throw std::runtime_error("unexhausted stack");
     if (returnValue.has_value()) push_thing(std::move(returnValue.value()));
+
+    if (!m_frames.empty()) {
+        m_flags = m_flags & ~executor_flags::Done;
+    } else {
+        m_flags = m_flags | executor_flags::Done;
+    }
+    m_flags = m_flags & ~executor_flags::JustHit;
+
     return frame;
 }
 
@@ -176,6 +191,14 @@ void executor::step() {
 
     struct frame& frame = m_frames.top();
 
+    if ((m_flags & executor_flags::JustHit) != executor_flags::JustHit && frame.mod->has_breakpoint(frame.position)) {
+        m_flags        = m_flags | executor_flags::Suspended | executor_flags::JustHit;
+        const auto& bp = frame.mod->breakpoint_at(frame.position);
+        bp.callback(*this, bp.data);
+        return;
+    }
+    m_flags = m_flags & ~executor_flags::JustHit;
+
     instruction instr{};
     frame.position += instr.read(frame.mod->bytecode_view().subview(frame.position));
     switch (instr.type) {