Added functionality to push and pop frames and values on framesc

src/vm/cpp_vm.cpp

@@ -1,14 +1,30 @@
 #include "cpp_vm.hpp"
+#include <iostream>
 
+/* Frame */
 Context::Frame::Frame(int s, Frame *p) :
   prev(p),
   next(0),
   size(s),
+  top(0),
   u(0)
 {
-  ;
+  u = new stack_entry[size];
+  for (int i = 0; i < size; i++) {
+    *(u+i)=0;
+  }
+}
+
+std::ostream& operator<<(std::ostream& os, const Context::Frame& f) {
+  os << "Frame at: " << &f << ", size: " << f.size;
+  return os;
 }
 
+Context::Frame::~Frame() {
+  delete [] u; // what happens to each element now?
+}
+
+/* Context */
 Context::Context(int initial_frame_size) :
   top(0),
   bottom(0)
@@ -63,6 +79,34 @@ void Context::pop_frame() {
   delete f;
 }
 
+void Context::push_on(stack_entry s) {
+  if (bottom == 0) {
+    //CMH: error
+    return;
+  }
+  if(bottom->top == bottom->size) {
+    //CMH: error
+    return;
+  }
+  *(bottom->u + bottom->top) = s;
+  bottom->top++;
+}
+
+Context::stack_entry Context::pop_off(bool zero) {
+  if (bottom->top < 1) {
+    //CMH: error
+    return 0;
+  }
+
+  bottom->top--;
+  stack_entry t = *(bottom->u + bottom->top);
+  if(zero) {
+    *(bottom->u + bottom->top) = 0;
+  }
+
+  return t;
+}
+
 Context::Context() :
   top(0),
   bottom(0)

src/vm/cpp_vm.hpp

@@ -1,34 +1,45 @@
 #ifndef CPP_VM_HPP
 #define CPP_VM_HPP 1
 
+#include <iosfwd>
+
 class Context {
+  typedef uint64_t stack_entry;
+
 public:
+  /* Frame */
   class Frame {
   private:
     Frame *prev;
     Frame *next;
     int size;
-    union {
-      void *obp;
-      unsigned long im;
-    } *u;
+    int top;
+    stack_entry *u;
 
     Frame(int s, Frame *p);
 
+    Frame(const Frame&);
+    Frame& operator=(const Frame&);
+
   public:
-
+    ~Frame();
+
     friend class Context;
     friend class TestContext;
+    friend std::ostream& operator<<(std::ostream&, const Context::Frame&);
   };
 
+  /* Registers */
   class Registers {
     friend class Context;
   };
 
+  /* Handler */
   class Handler {
     friend class Context;
   };
 
+  /* Meta */
   class Meta {
     friend class Context;
   };
@@ -45,9 +56,14 @@ class Context {
   explicit Context(int initial_frame_size); // no conversion constructor
   ~Context();
 
+  /* Frame management */
   Frame * push_new_frame(int size);
   void pop_frame();
 
+  /* Values on frame */
+  void push_on(stack_entry);
+  stack_entry pop_off(bool zero=false);
+
   friend class TestContext;
 };
 

src/vm/test/test_context.cpp

@@ -4,61 +4,122 @@
 
 class TestContext {
 public:
-  static void test() {
+  static void test_frames() {
     Context  c;
     Context::Frame *t;
 
+    std::cout << "===test_frames===" << std::endl;
+
     c.push_new_frame(0);
     std::cout << "Frame 0" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.push_new_frame(1);
     std::cout << "Frame 1" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.push_new_frame(2);
     std::cout << "Frame 2" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.push_new_frame(3);
     std::cout << "Frame 3" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.pop_frame();
     std::cout << "Frame 2" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.pop_frame();
     std::cout << "Frame 1" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.pop_frame();
     std::cout << "Frame 0" << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
     }
 
     c.pop_frame();
     std::cout << "Frame NULL" << std::endl;
     std::cout << "top: " << c.top << ", bottom: " << c.bottom << std::endl;
     for(t = c.top; t != 0; t = t->next) {
-      std::cout << t << std::endl;
+      std::cout << *t << std::endl;
+    }
+  }
+
+  static void test_values() {
+    Context  c;
+    Context::Frame *t;
+
+    std::cout << std::endl << "===test_values==" << std::endl;
+
+    c.push_new_frame(5);
+    c.push_on(1);
+    c.push_on(2);
+    c.push_on(3);
+
+    std::cout << "Frame 0" << std::endl;
+    t = c.bottom;
+    std::cout << *t << std::endl;
+    for (int i = 0; i < t->top; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
+    }
+    std::cout << "unused stack:" << std::endl;    
+    for (int i = t->top; i < t->size; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
+    }
+
+    c.push_new_frame(10);
+    c.push_on(11);
+    c.push_on(12);
+
+    std::cout << "Frame 1" << std::endl;
+    t = c.bottom;
+    std::cout << *t << std::endl;
+    for (int i = 0; i < t->top; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
+    }
+    std::cout << "unused stack:" << std::endl;
+    for (int i = t->top; i < t->size; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
+    }
+
+    c.pop_frame();
+    c.pop_off(true);
+
+    std::cout << "Frame 0" << std::endl;
+    t = c.bottom;
+    std::cout << *t << std::endl;
+    for (int i = 0; i < t->top; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
+    }
+    std::cout << "unused stack:" << std::endl;    
+    for (int i = t->top; i < t->size; i++) {
+      std::cout << "i: " << i << ", content: " << (t->u + i) <<
+	", value: " << *(t->u + i) << std::endl;
     }
   }
 };
 
 int main(void) {
-  TestContext::test();
+  TestContext::test_frames();
+  TestContext::test_values();
 }