Added PUTS instruction

KCreate · KCreate · commit 7b235ce22a18 · 2017-03-27T23:23:23.000+02:00
diff --git a/spec/machine_spec.cr b/spec/machine_spec.cr
@@ -189,6 +189,23 @@ describe StackVM::Machine do
       machine.stack_read_value(Float32).should eq 50
     end
 
+    it "runs PUTS" do
+      io = IO::Memory.new
+
+      machine = Machine.new(64, output: io)
+      machine.flash Assembler::Utils.convert_opcodes EXE{
+        LOADI, BYTE, 0_u8,
+        LOADI, BYTE, 1_u8,
+        LOADI, BYTE, 2_u8,
+        LOADI, BYTE, 3_u8,
+        PUTS, DWORD,
+        HALT
+      }
+      machine.start
+
+      io.to_s.should eq "Bytes[0, 1, 2, 3]\n"
+    end
+
   end
 
 end
diff --git a/src/stackvm.cr b/src/stackvm.cr
@@ -11,36 +11,12 @@ module StackVM
 
   # Compile the above program to bytes
   binary = Assembler::Utils.convert_opcodes EXE{
+    LOADI, BYTE, 0_u8,
+    LOADI, BYTE, 1_u8,
+    LOADI, BYTE, 2_u8,
+    LOADI, BYTE, 3_u8,
 
-    # 64 bit signed int
-    LOADI, QWORD, 25_u64,
-    LOADI, QWORD, 25_u64,
-    ADD | M_B,
-
-    # 32 bit signed int
-    LOADI, DWORD, 25_u32,
-    LOADI, DWORD, 25_u32,
-    ADD,
-
-    # 64 bit unsigned int
-    LOADI, QWORD, 25_u64,
-    LOADI, QWORD, 25_u64,
-    ADD | M_B | M_S,
-
-    # 32 bit unsigned int
-    LOADI, DWORD, -1.to_u32,
-    LOADI, DWORD, 25_u32,
-    ADD | M_S,
-
-    # 64 bit float
-    LOADI, QWORD, 25_f64,
-    LOADI, QWORD, 25_f64,
-    ADD | M_B | M_T,
-
-    # 32 bit float
-    LOADI, DWORD, 25_f32,
-    LOADI, DWORD, 25_f32,
-    ADD | M_T,
+    PUTS, DWORD,
 
     HALT
   }
diff --git a/src/stackvm/machine/debugger.cr b/src/stackvm/machine/debugger.cr
@@ -50,6 +50,7 @@ module StackVM::Machine::Utils
         rescue e : Exception
           @output.puts "An exception happened:"
           @output.puts e
+          @output.puts e.backtrace.join "\n"
         end
       end
     end
diff --git a/src/stackvm/machine/machine.cr b/src/stackvm/machine/machine.cr
@@ -12,7 +12,11 @@ module StackVM::Machine
     property instruction : Instruction
     property executable_size : UInt64
 
-    def initialize(memory_size = DEFAULT_MEMORY_SIZE)
+    property input : IO
+    property output : IO
+    property error : IO
+
+    def initialize(memory_size = DEFAULT_MEMORY_SIZE, @input = STDIN, @output = STDOUT, @error = STDERR)
       @regs = Slice(UInt64).new(20, 0_u64)
       @memory = Slice(UInt8).new(memory_size, 0_u8)
       @instruction = Instruction.new 0b00000000_00110000_u16
@@ -123,6 +127,10 @@ module StackVM::Machine
         return op_exp
       when OP::LOADI
         return op_loadi
+      when OP::NOP
+        return false
+      when OP::PUTS
+        return op_puts
       when OP::HALT
         return op_halt
       else
@@ -256,6 +264,11 @@ module StackVM::Machine
       value
     end
 
+    # Reads *amount* of bytes from the stack
+    def stack_read_bytes(amount)
+      memory_read @regs[Reg::SP] - amount, amount
+    end
+
     # Pops a *type* value from the stack
     def stack_read_value(type : Number.class)
       memory_read_value @regs[Reg::SP] - sizeof(typeof(type)), type
@@ -505,16 +518,35 @@ module StackVM::Machine
 
       # Decodes the amount of bytes that are being pushed
       type = memory_read(@regs[Reg::IP] + 2, 2)
-      type = Pointer(UInt32).new type.to_unsafe.address
-      amount_of_bytes = type[0]
+      amount_of_bytes = IO::ByteFormat::LittleEndian.decode UInt16, type
 
-      # Reads *type* bytes
+      # Reads *amount_of_bytes* bytes
       value = memory_read(@regs[Reg::IP] + 6, amount_of_bytes)
       stack_push value
 
       return false
     end
 
+    # Executes a PUTS instruction
+    #
+    # ```
+    # LOADI BYTE 25
+    # LOADI BYTE 50
+    # PUTS WORD # => prints [25, 50]
+    # ```
+    def op_puts
+
+      # Decodes the amount of bytes that are being read
+      type = memory_read(@regs[Reg::IP] + 2, 2)
+      amount_of_bytes = IO::ByteFormat::LittleEndian.decode UInt16, type
+
+      # Reads *amount_of_bytes* bytes
+      value = stack_read_bytes amount_of_bytes
+      @output.puts value
+
+      return false
+    end
+
     # Executes a HALT instruction
     #
     # ```
