nodes: make some obvious dead-code raise a log message (Info)

compiler/nodes.py

@@ -5,7 +5,7 @@ from abc import abstractmethod, ABC
 from typing import Any, Iterable
 
 from . import ir, semantic, lexer
-from .errors import SemanticAnalysisError, OverrideMandatoryError
+from .errors import SemanticAnalysisError, OverrideMandatoryError, CompilationWarning, Levels
 from .logger import Logger
 from .source import SourceLocation
 from .typechecking import typecheck
@@ -291,7 +291,12 @@ class Block(Statement):
     def intermediate_representation(self) -> list[ir.IRItem]:
         result: list[ir.IRItem] = []
         for node in self.nodes:
-            if not node.pure:
+            if node.pure:
+                CompilationWarning(node.location(),
+                                   f"{node.__class__.__name__} ignored as it doesn't have any "
+                                   f"visible side effect.",
+                                   level=Levels.Info).raise_warning()
+                continue
             result += node.intermediate_representation()
         return result