More helpful error messages

src/pystencils/backend/ast/structural.py

@@ -320,7 +320,7 @@ class PsPragma(PsLeafMixIn, PsEmptyLeafMixIn, PsAstNode):
     Example usage: ``PsPragma("omp parallel for")`` translates to ``#pragma omp parallel for``.
 
     Args:
-        text: The pragmas text, without the ``#pragma``.
+        text: The pragma's text, without the ``#pragma``.
     """
 
     __match_args__ = ("text",)

src/pystencils/backend/emission.py

@@ -50,11 +50,13 @@ from .ast.expressions import (
     PsLt,
     PsGe,
     PsLe,
-    PsSubscript
+    PsSubscript,
+    PsBufferAcc,
 )
 
 from .extensions.foreign_ast import PsForeignExpression
 
+from .exceptions import PsInternalCompilerError
 from .memory import PsSymbol
 from ..types import PsScalarType, PsArrayType
 
@@ -386,6 +388,12 @@ class CAstPrinter:
                 foreign_code = node.get_code(self.visit(c, pc) for c in children)
                 pc.pop_op()
                 return foreign_code
+            
+            case PsBufferAcc():
+                raise PsInternalCompilerError(
+                    f"Unable to print C code for buffer access {node}.\n"
+                    f"Buffer accesses must be lowered using the `LowerToC` pass before emission."
+                )
 
             case _:
                 raise NotImplementedError(f"Don't know how to print {node}")