errors: add warning implementation + fix a few issues

compiler/errors.py

@@ -1,20 +1,38 @@
 from __future__ import annotations
 
 import inspect
+import sys
 
 from . import source, lexer
 
 
 class CompilationError(Exception):
     def __init__(self, location: source.SourceLocation, message: str = "Unknown error"):
-        super().__init__(f"{str(location)}: {message} ")
+        super().__init__(f"{str(location)}: \033[1merror:\033[0m {message}")
         self.location = location
 
 
+class CompilationWarning(Warning):
+    _pending_warnings: list[CompilationWarning] = []
+
+    def __init__(self, location: source.SourceLocation, message: str = "Unknown warning"):
+        super().__init__(f"{str(location)}: \033[1mwarning:\033[0m {message}")
+        self.location = location
+
+    @classmethod
+    def show_warnings(cls, _source: str):
+        for warning in CompilationWarning._pending_warnings:
+            warning.location.source = _source
+            print(f"{warning}\n{warning.location.show_in_source()}", file=sys.stderr)
+
+    def raise_warning(self):
+        CompilationWarning._pending_warnings += [self]
+
+
 class UnexpectedTokenError(CompilationError):
     def __init__(self, got: lexer.Token, wanted: lexer.Tokens | str):
         message = wanted
-        if type(wanted) == lexer.Tokens:
+        if isinstance(wanted, lexer.Tokens):
             message = str(wanted)
         super().__init__(got.loc, f"Unexpected token '{got}', wanted {message}")
 
@@ -23,6 +41,12 @@ class SemanticAnalysisError(CompilationError):
     pass
 
 
+class CodegenError(Exception):
+    def __init__(self, ir_location: source.IRLocation, message: str = "Unknown codegen error"):
+        super().__init__(f"Codegen error: {message}\n{str(ir_location)}")
+        pass
+
+
 class OverrideMandatoryError(NotImplementedError):
     def __init__(self, klass: object = None, function_name: str = None):
         if klass is None or function_name is None: