From 349fd6ff7886ffb14e68e7cfd043fe4505834ac3 Mon Sep 17 00:00:00 2001
From: Mitchell Plamann <mitchell.plamann@gmail.com>
Date: Sun, 19 Apr 2015 19:48:45 -0400
Subject: [PATCH] Start of a breakpoints system

---
 src/bytecode-parser.js |  1 +
 src/c0vm.js            | 49 ++++++++++++++++++++++++++++++------------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/src/bytecode-parser.js b/src/bytecode-parser.js
index 891a1af..00f8da9 100644
--- a/src/bytecode-parser.js
+++ b/src/bytecode-parser.js
@@ -85,6 +85,7 @@ var Bc0File = function (filename) {
     this.function_pool = [];
     for (var i = 0; i < this.function_count; i++) {
         this.function_pool.push(new FunctionInfo(stream));
+        this.function_pool[i].function_id = i;
     }
 
     this.native_count = stream.get_u2();
diff --git a/src/c0vm.js b/src/c0vm.js
index 768964c..a7e7414 100755
--- a/src/c0vm.js
+++ b/src/c0vm.js
@@ -42,6 +42,7 @@ var StackFrame = function(file, f) {
     this.stack = [];
     this.pc = 0;
     this.program = f.code;
+    this.function_id = f.function_id;
     this.variables = [];
     for (var i = 0; i < f.num_vars; i++)
         this.variables.push(0);
@@ -69,6 +70,8 @@ var ProgramState = function(parsed_file, callback_dict) {
         }
     }
 
+    this.breakpoints = [];
+
     // Memory is just a big array of bytes, right?
     // "Allocation" is appending onto this array
     // A pointer to memory is an index into this array.
@@ -470,8 +473,11 @@ ProgramState.prototype.step = function() {
     }
 }
 
-// Takes in a parsed .bc0 file and runs it
-function execute(file, callbacks, v) {
+ProgramState.prototype.set_breakpoint = function(function_index, opcode_index) {
+    this.breakpoints.push([function_index, opcode_index]);
+}
+
+function initialize_vm(file, callbacks, v) {
     verbose = typeof v !== 'undefined' ? v : true;
     log("Initializing with file " + file);
 
@@ -481,25 +487,40 @@ function execute(file, callbacks, v) {
 
     log("Beginning execution");
 
+    return state;
+}
+
+function run_vm(vm) {
     while (true) {
-        var val = state.step();
+        for (breakpoint in vm.breakpoints) {
+            if (vm.frame.function_id == breakpoint[0] &&
+                vm.frame.pc == breakpoint[1]) {
+                console.log("Breakpoint reached!");
+                return vm;
+            }
+        }
+        
+        var val = vm.step();
         if (val !== undefined) return val;
 
         if (verbose) {
-            console.log("Machine state:");
+            console.log("Machine vm:");
             console.log("  Current Stack Frame:");
-            console.log("    Stack: " + state.frame.stack);
-            console.log("    PC:    " + state.frame.pc);
-            console.log("    Vars:  " + state.frame.variables);
-            // console.log("    Code:  " + state.frame.program);
-            console.log("  Heap: " + state.heap);
+            console.log("    Stack: " + vm.frame.stack);
+            console.log("    PC:    " + vm.frame.pc);
+            console.log("    Vars:  " + vm.frame.variables);
+            // console.log("    Code:  " + vm.frame.program);
+            console.log("  Heap: " + vm.heap);
         }
-
-        // if (at_breakpoint) {
-        //   save state (maybe in a global in this file?)
-        //   return;
-        // }
     }
 }
 
+// Takes in a parsed .bc0 file and runs it
+function execute(file, callbacks, v) {
+    var state = initialize_vm(file, callbacks, v);
+    return run_vm(state);
+}
+
 exports.execute = execute;
+exports.initialize_vm = initialize_vm;
+exports.run_vm = run_vm;