From 5a5953ca4caa8feb0e6e0587dd85d7c3550cc052 Mon Sep 17 00:00:00 2001
From: Chris Pressey <cpressey@catseye.tc>
Date: Sun, 18 Oct 2015 18:12:47 +0100
Subject: [PATCH] A little awkward, but analyze byte table access correctly.

---
 src/sixtypical/analyzer.py   |  19 ++++++
 tests/SixtyPical Analysis.md | 110 +++++++++++++++++++++++++++++++++++
 2 files changed, 129 insertions(+)

diff --git a/src/sixtypical/analyzer.py b/src/sixtypical/analyzer.py
index b3806f5..9ab4053 100644
--- a/src/sixtypical/analyzer.py
+++ b/src/sixtypical/analyzer.py
@@ -2,6 +2,7 @@
 
 from sixtypical.ast import Program, Routine, Block, Instr
 from sixtypical.model import (
+    TYPE_BYTE, TYPE_BYTE_TABLE,
     ConstantRef, LocationRef, FLAG_Z, FLAG_N, FLAG_V, FLAG_C
 )
 
@@ -34,6 +35,10 @@ class UsageClashError(StaticAnalysisError):
     pass
 
 
+class TypeMismatchError(StaticAnalysisError):
+    pass
+
+
 class Context():
     def __init__(self, inputs, outputs, trashes):
         self._store = {}  # Ref -> INITALIZED/UNINITIALIZED
@@ -137,10 +142,24 @@ def analyze_instr(instr, context, routines):
     src = instr.src
 
     if opcode == 'ld':
+        if instr.index:
+            if src.type == TYPE_BYTE_TABLE and dest.type == TYPE_BYTE:
+                pass
+            else:
+                raise TypeMismatchError((src, dest))
+        elif src.type != dest.type:
+            raise TypeMismatchError((src, dest))
         context.assert_initialized(src)
         context.assert_writeable(dest, FLAG_Z, FLAG_N)
         context.set_initialized(dest, FLAG_Z, FLAG_N)
     elif opcode == 'st':
+        if instr.index:
+            if src.type == TYPE_BYTE and dest.type == TYPE_BYTE_TABLE:
+                pass
+            else:
+                raise TypeMismatchError((src, dest))
+        elif src.type != dest.type:
+            raise TypeMismatchError((src, dest))
         context.assert_initialized(src)
         context.assert_writeable(dest)
         context.set_initialized(dest)
diff --git a/tests/SixtyPical Analysis.md b/tests/SixtyPical Analysis.md
index 8d8a00c..e5f3935 100644
--- a/tests/SixtyPical Analysis.md	
+++ b/tests/SixtyPical Analysis.md	
@@ -195,6 +195,116 @@ Can't `st` to a memory location that doesn't appear in (outputs ∪ trashes).
     | }
     ? IllegalWriteError: lives
 
+Storing to a table, you must use an index, and vice-versa.
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs one
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, one
+    | }
+    = ok
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs many
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, many
+    | }
+    ? TypeMismatchError
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs one
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, one + x
+    | }
+    ? TypeMismatchError
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs many
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, many + x
+    | }
+    = ok
+
+Reading from a table, you must use an index, and vice-versa.
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs one
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     st x, one
+    |     ld a, one
+    | }
+    = ok
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs one
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     st x, one
+    |     ld a, one + x
+    | }
+    ? TypeMismatchError
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs many
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, many + x
+    |     ld a, many
+    | }
+    ? TypeMismatchError
+
+    | byte one
+    | byte table many
+    | 
+    | routine main
+    |   outputs many
+    |   trashes a, x, n, z
+    | {
+    |     ld x, 0
+    |     ld a, 0
+    |     st a, many + x
+    |     ld a, many + x
+    | }
+    = ok
+
 ### add ###
 
 Can't `add` from or to a memory location that isn't initialized.