Make ld parse to a IndexedRef or IndirectRef (latter still todo.)

README.md

@@ -1,7 +1,7 @@
 SixtyPical
 ==========
 
-_Version 0.11.  Work-in-progress, everything is subject to change._
+_Version 0.12.  Work-in-progress, everything is subject to change._
 
 SixtyPical is a very low-level programming language, similar to 6502 assembly,
 with static analysis through abstract interpretation.

src/sixtypical/analyzer.py

@@ -127,6 +127,9 @@ class Context(object):
                     if kwargs.get('message'):
                         message += ' (%s)' % kwargs['message']
                     raise exception_class(message)
+            elif isinstance(ref, IndexedRef):
+                self.assert_meaningful(ref.ref, **kwargs)
+                self.assert_meaningful(ref.index, **kwargs)
             else:
                 raise NotImplementedError(ref)
 
@@ -236,14 +239,16 @@ class Analyzer(object):
         src = instr.src
     
         if opcode == 'ld':
-            if instr.index:
+            if isinstance(src, IndexedRef):
-                if TableType.is_a_table_type(src.type, TYPE_BYTE) and dest.type == TYPE_BYTE:
+                if TableType.is_a_table_type(src.ref.type, TYPE_BYTE) and dest.type == TYPE_BYTE:
                     pass
                 else:
                     raise TypeMismatchError('%s and %s in %s' %
-                        (src.name, dest.name, self.current_routine.name)
+                        (src.ref.name, dest.name, self.current_routine.name)
                     )
-                context.assert_meaningful(instr.index)
+                context.assert_meaningful(src.index)
+            elif isinstance(src, IndirectRef):
+                raise NotImplementedError
             elif src.type != dest.type:
                 raise TypeMismatchError('%s and %s in %s' %
                     (src.name, dest.name, self.current_routine.name)
@@ -352,6 +357,9 @@ class Analyzer(object):
                 context.assert_meaningful(src)
 
         elif opcode == 'copy':
+            if dest == REG_A:
+                raise ForbiddenWriteError("{} cannot be used as destination for copy".format(dest))
+
             # 1. check that their types are compatible
 
             if isinstance(src, AddressRef) and isinstance(dest, LocationRef):

src/sixtypical/compiler.py

@@ -131,9 +131,9 @@ class Compiler(object):
                     self.emitter.emit(TYA())
                 elif isinstance(src, ConstantRef):
                     self.emitter.emit(LDA(Immediate(Byte(src.value))))
-                elif instr.index == REG_X:
+                elif isinstance(src, IndexedRef) and src.index == REG_X:
                     self.emitter.emit(LDA(AbsoluteX(self.labels[src.name])))
-                elif instr.index == REG_Y:
+                elif isinstance(src, IndexedRef) and src.index == REG_Y:
                     self.emitter.emit(LDA(AbsoluteY(self.labels[src.name])))
                 else:
                     self.emitter.emit(LDA(Absolute(self.labels[src.name])))
@@ -142,7 +142,7 @@ class Compiler(object):
                     self.emitter.emit(TAX())
                 elif isinstance(src, ConstantRef):
                     self.emitter.emit(LDX(Immediate(Byte(src.value))))
-                elif instr.index == REG_Y:
+                elif isinstance(src, IndexedRef) and src.index == REG_Y:
                     self.emitter.emit(LDX(AbsoluteY(self.labels[src.name])))
                 else:
                     self.emitter.emit(LDX(Absolute(self.labels[src.name])))
@@ -151,7 +151,7 @@ class Compiler(object):
                     self.emitter.emit(TAY())
                 elif isinstance(src, ConstantRef):
                     self.emitter.emit(LDY(Immediate(Byte(src.value))))
-                elif instr.index == REG_X:
+                elif isinstance(src, IndexedRef) and src.index == REG_X:
                     self.emitter.emit(LDY(AbsoluteX(self.labels[src.name])))
                 else:
                     self.emitter.emit(LDY(Absolute(self.labels[src.name])))

src/sixtypical/model.py

@@ -202,7 +202,8 @@ class IndexedRef(Ref):
 
     @property
     def name(self):
-        return '{}+{}'.format(self.ref.name, self.index.name)
+        return self.ref.name
+        #return '{}+{}'.format(self.ref.name, self.index.name)
 
     def is_constant(self):
         return False

src/sixtypical/parser.py

@@ -316,7 +316,15 @@ class Parser(object):
                 self.scanner.expect('forever')
             return Instr(opcode='repeat', dest=None, src=src,
                          block=block, inverted=inverted)
-        elif self.scanner.token in ("ld", "add", "sub", "cmp", "and", "or", "xor"):
+        elif self.scanner.token in ("ld",):
+            # the same as add, sub, cmp etc below, except supports an indlocexpr for the src
+            opcode = self.scanner.token
+            self.scanner.scan()
+            dest = self.locexpr()
+            self.scanner.expect(',')
+            src = self.indlocexpr()
+            return Instr(opcode=opcode, dest=dest, src=src, index=None)
+        elif self.scanner.token in ("add", "sub", "cmp", "and", "or", "xor"):
             opcode = self.scanner.token
             self.scanner.scan()
             dest = self.locexpr()

tests/SixtyPical Analysis.md

@@ -1462,6 +1462,21 @@ Can `copy` from a `byte` to a `byte`.
     | }
     = ok
 
+The understanding is that, because `copy` trashes `a`, `a` cannot be used
+as the destination of a `copy`.
+
+    | byte source : 0
+    | byte dest
+    | 
+    | routine main
+    |   inputs source
+    |   outputs dest
+    |   trashes a, z, n
+    | {
+    |     copy source, a
+    | }
+    ? ForbiddenWriteError
+
 Can `copy` from a `word` to a `word`.
 
     | word source : 0
@@ -1504,9 +1519,7 @@ Can't `copy` from a `word` to a `byte`.
     | }
     ? TypeMismatchError
 
-### copy[] ###
+### Buffers and pointers ###
-
-Buffers and pointers.
 
 Note that `^buf` is a constant value, so it by itself does not require `buf` to be
 listed in any input/output sets.
@@ -1588,6 +1601,24 @@ Read through a pointer.
     | }
     = ok
 
+Read through a pointer to the `a` register.  Note that
+this is done with `ld`, not `copy`.
+
+    | buffer[2048] buf
+    | pointer ptr
+    | byte foo
+    | 
+    | routine main
+    |   inputs buf
+    |   outputs foo
+    |   trashes a, y, z, n, ptr
+    | {
+    |     ld y, 0
+    |     copy ^buf, ptr
+    |     ld a, [ptr] + y
+    | }
+    = ok
+
 ### routines ###
 
 Routines are constants.  You need not, and in fact cannot, specify a constant

tests/SixtyPical Compilation.md

@@ -846,7 +846,7 @@ Read through a pointer, into a byte storage location, or the `a` register.
     |     ld y, 0
     |     copy ^buf, ptr
     |     copy [ptr] + y, foo
-    |     copy [ptr] + y, a
+    |     ld a, [ptr] + y
     | }
     = $080D   LDY #$00
     = $080F   LDA #$1F