better compiler debugging

added test for defaults

resources/profiles/debug_compiler.json

@@ -2,8 +2,7 @@
 // from nim itself (the nim compiler options are identical to those of
 // production.json)
 {"flags": {
-        "gc": "none",
-        "d": "danger"
+        "gc": "none"
         },
  "verbose": true,
  "override_config": true,

src/compiler.nim

@@ -36,6 +36,8 @@ import config
 when isMainModule:
     import util/debug
 import types/methods
+when DEBUG_TRACE_COMPILER:
+    import terminal
 
 
 type
@@ -212,7 +214,11 @@ proc emitByte(self: Compiler, byt: OpCode|uint8) =
     ## Emits a single bytecode instruction and writes it
     ## to the current chunk being compiled
     when DEBUG_TRACE_COMPILER:
-        echo "DEBUG - Compiler: Emitting " & $byt & " (uint8 value of " & $(uint8 byt) & ")"
+        write stdout, &"DEBUG - Compiler: Emitting {$byt} (uint8 value of  {$(uint8 byt)}"
+        if byt.int() <= OpCode.high().int():
+          write stdout, &"; opcode value of {$byt.OpCode}"
+        write stdout, ")\n"
+          
     self.currentChunk.writeChunk(uint8 byt, self.parser.previous.line)
 
 
@@ -652,6 +658,10 @@ proc emitJump(self: Compiler, opcode: OpCode): int =
     self.emitByte(opcode)
     self.emitByte(0xff)
     self.emitByte(0xff)
+    when DEBUG_TRACE_COMPILER:
+        setForegroundColor(fgYellow)
+        write stdout, &"DEBUG - Compiler: emit jump @ {self.currentChunk.code.len-2}\n"
+        setForegroundColor(fgDefault)
     return self.currentChunk.code.len - 2
 
 
@@ -669,14 +679,23 @@ proc patchJump(self: Compiler, offset: int) =
     ## be jumped over, so the size of the if/else conditions
     ## or loops is limited (hopefully 65 thousands and change
     ## instructions are enough for everyone)
+
+    when DEBUG_TRACE_COMPILER:
+        setForegroundColor(fgYellow)
+        write stdout, &"DEBUG - Compiler: patching jump @ {offset}"
     let jump = self.currentChunk.code.len - offset - 2
     if jump > (int uint16.high):
+        when DEBUG_TRACE_COMPILER:
+            setForegroundColor(fgDefault)
+            write stdout, "\n"
         self.compileError("too much code to jump over")
     else:
         let casted = toDouble(jump)
         self.currentChunk.code[offset] = casted[0]
         self.currentChunk.code[offset + 1] = casted[1]
-
+        when DEBUG_TRACE_COMPILER:
+            write stdout, &" points to {casted[0]}, {casted[1]} = {jump}\n"
+            setForegroundColor(fgDefault)
 
 proc ifStatement(self: Compiler) =
     ## Parses if statements in a C-style fashion
@@ -703,14 +722,22 @@ proc ifStatement(self: Compiler) =
 
 proc emitLoop(self: Compiler, start: int) =
     ## Creates a loop and emits related instructions.
+    when DEBUG_TRACE_COMPILER:
+        setForegroundColor(fgYellow)
+        write stdout, &"DEBUG - Compiler: emitting loop at start {start} "
     self.emitByte(OpCode.Loop)
     var offset = self.currentChunk.code.len - start + 2
     if offset > (int uint16.high):
+        when DEBUG_TRACE_COMPILER:
+            setForegroundColor(fgDefault)
+            write stdout, "\n"
         self.compileError("loop body is too large")
     else:
         let offsetBytes = toDouble(offset)
         self.emitByte(offsetBytes[0])
         self.emitByte(offsetBytes[1])
+        when DEBUG_TRACE_COMPILER:
+            write stdout, &"pointing to {offsetBytes[0]}, {offsetBytes[1]} = {offset}\n"
 
 
 proc endLooping(self: Compiler) =

src/util/debug.nim

@@ -21,6 +21,7 @@ import ../types/methods
 import ../types/arraylist
 import strformat
 import terminal
+import ../multibyte
 
 proc printName(name: string) =
     setForegroundColor(fgGreen)
@@ -62,11 +63,9 @@ proc constantInstruction(name: string, chunk: Chunk, offset: int): int =
 
 proc jumpInstruction(name: string, chunk: Chunk, offset: int): int =
     var jumpArray: array[2, uint8] = [chunk.code[offset + 1], chunk.code[offset + 2]]
-    var jump: int
-    copyMem(jump.addr, jumpArray.addr, sizeof(uint16))
     write stdout, &"DEBUG - VM:\tInstruction -> "
     printName(name)
-    write stdout, &"\nDEBUG - VM:\tJump size -> {jump}"
+    write stdout, &"\nDEBUG - VM:\tJump size -> {jumpArray.fromDouble()} ( = {$jumpArray[0]}, {$jumpArray[1]})"
     nl()
     return offset + 3
 

src/vm.nim

@@ -38,6 +38,7 @@ import types/typeutils
 import types/function
 import types/native
 import types/arraylist
+import multibyte
 # We always import it to
 # avoid the compiler complaining
 # about functions not existing
@@ -281,9 +282,7 @@ proc readBytes(self: CallFrame): int =
 proc readShort(self: CallFrame): uint16 =
     ## Reads a 16 bit number from the
     ## given frame's chunk
-    let arr = [self.readByte(), self.readByte()]
-    copyMem(result.addr, unsafeAddr(arr), sizeof(uint16))
-
+    fromDouble([self.readByte(), self.readByte()])
 
 proc readConstant(self: CallFrame): ptr Obj =
     ## Reads a constant from the given

tests/japl/defaults.jpl

@@ -0,0 +1,11 @@
+//[Test: defaults]
+//[skip]
+//[source:mixed]
+var a = 3;
+fun test(b = a) {
+  print (b);
+}
+a = 9;
+test();//stdout:3
+//[end]
+//[end]