move the VM stack off the real stack + std cleanups

src/cs_std.hh

@@ -15,19 +15,16 @@ namespace cubescript {
 
 /* run func, call the second one after finishing */
 
-template<typename F>
-struct CsScopeExit {
-    template<typename FF>
-    CsScopeExit(FF &&f): func(std::forward<FF>(f)) {}
-    ~CsScopeExit() {
-        func();
-    }
-    std::decay_t<F> func;
-};
-
 template<typename F1, typename F2>
 inline void call_with_cleanup(F1 &&dof, F2 &&clf) {
-    CsScopeExit<F2> cleanup(std::forward<F2>(clf));
+    struct scope_exit {
+        scope_exit(std::decay_t<F2> &f): func(&f) {}
+        ~scope_exit() {
+            (*func)();
+        }
+        std::decay_t<F2> *func;
+    };
+    scope_exit cleanup(clf);
     dof();
 }
 
@@ -72,10 +69,19 @@ struct valbuf {
     void reserve(std::size_t s) { buf.reserve(s); }
     void resize(std::size_t s) { buf.resize(s); }
 
+    void resize(std::size_t s, value_type const &v) {
+        buf.resize(s, v);
+    }
+
     void append(T const *beg, T const *end) {
         buf.insert(buf.end(), beg, end);
     }
 
+    template<typename ...A>
+    reference emplace_back(A &&...args) {
+        return buf.emplace_back(std::forward<A>(args)...);
+    }
+
     void push_back(T const &v) { buf.push_back(v); }
     void pop_back() { buf.pop_back(); }
 

src/cs_thread.cc

@@ -0,0 +1,19 @@
+#include "cs_thread.hh"
+
+#include "cs_gen.hh"
+
+namespace cubescript {
+
+thread_state::thread_state(internal_state *cs):
+    vmstack{cs}, errbuf{cs}
+{
+    vmstack.reserve(MAX_ARGUMENTS + MAX_RESULTS);
+}
+
+hook_func thread_state::set_hook(hook_func f) {
+    auto hk = std::move(call_hook);
+    call_hook = std::move(f);
+    return hk;
+}
+
+} /* namespace cubescript */

src/cs_thread.hh

@@ -17,6 +17,8 @@ struct thread_state {
     ident_link *callstack{};
     /* current codegen state for diagnostics */
     codegen_state *cstate{};
+    /* value stack for VM */
+    valbuf<any_value> vmstack;
     /* per-thread storage buffer for error messages */
     charbuf errbuf;
     /* we can attach a hook to vm events */
@@ -24,15 +26,9 @@ struct thread_state {
     /* loop nesting level */
     int loop_level = 0;
 
-    thread_state(internal_state *cs):
-        errbuf{cs}
-    {}
+    thread_state(internal_state *cs);
 
-    hook_func set_hook(hook_func f) {
-        auto hk = std::move(call_hook);
-        call_hook = std::move(f);
-        return hk;
-    }
+    hook_func set_hook(hook_func f);
 
     hook_func &get_hook() { return call_hook; }
     hook_func const &get_hook() const { return call_hook; }

src/meson.build

@@ -11,6 +11,7 @@ libcubescript_src = [
     'cs_parser.cc',
     'cs_state.cc',
     'cs_strman.cc',
+    'cs_thread.cc',
     'cs_val.cc',
     'cs_vm.cc',
     'lib_base.cc',