feat(furdb): add break command

furdb/include/command.hpp

@@ -36,4 +36,9 @@ 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;
+};
+
 #endif // COMMAND_HPP

furdb/include/context.hpp

@@ -13,6 +13,7 @@ struct context {
     furvm::function_h mainFunction;
 
     bool running = true;
+    bool halt    = false;
 
     void run();
 };

furdb/src/command.cpp

@@ -1,5 +1,10 @@
 #include "command.hpp"
 
+#include "furvm/executor.hpp"
+#include "furvm/function.hpp"
+#include "furvm/module.hpp"
+#include "furvm/thing.hpp"
+
 #include <cctype>
 #include <cstddef>
 #include <iostream>
@@ -51,5 +56,31 @@ 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";
+}
+
+static void breakpoint_hit(furvm::executor& executor, void* data) {
+    std::cout << "Breakpoint hit\n";
+    context* ctx = reinterpret_cast<context*>(data);
+    ctx->halt    = true;
+}
+
+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";
 }

furdb/src/context.cpp

@@ -1,9 +1,15 @@
 #include "context.hpp"
 
+#include <furvm/executor.hpp>
+#include <iostream>
+
 void context::run() {
     if ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done)
         executor->push_frame(mod, *mainFunction);
-    while ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done) {
+    while ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done && !halt) {
         executor->step();
     }
+    if ((executor->flags() & furvm::executor_flags::Done) == furvm::executor_flags::Done) {
+        std::cout << "Execution finished\n";
+    }
 }

furdb/src/main.cpp

@@ -43,8 +43,9 @@ 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["break"] = s_commands["b"] = new break_command();
 
     try {
         std::ifstream file(argv[1], std::ios::binary | std::ios::in);

furvm/include/furvm/module.hpp

@@ -147,7 +147,7 @@ struct mod_type {
 
 struct breakpoint {
     std::function<void(executor&, void*)> callback;
-    void*                                 data;
+    void*                                 data = nullptr;
 };
 
 class mod {