ir: IRValue: track readers

compiler/ir.py

@@ -43,9 +43,25 @@ class IRNop(IRAction):
 
 
 class IRValue(IRItem, abc.ABC):
+    values: list[IRValue] = []
+
+    def __init__(self, location: SourceLocation):
+        super().__init__(location)
+        self.readers: list[IRAction] = []
+        IRValue.values += [self]
+
+    def __del__(self):
+        IRValue.values.remove(self)
+
     def destination(self) -> IRValue:
         return self
 
+    def __str__(self):
+        return self.codegen()
+
+    def __repr__(self) -> str:
+        return f"{self.codegen()} (readers: {repr(self.readers)})"
+
 
 class IRMove(IRAction):