fix[lang]: disallow blockhash in pure functions

tests/parser/features/decorators/test_pure.py

@@ -129,3 +129,17 @@ def foo() -> uint256:
         ),
         FunctionDeclarationException,
     )
+
+
+def test_invalid_builtin(get_contract, assert_compile_failed):
+    assert_compile_failed(
+        lambda: get_contract(
+            """
+@external
+@pure
+def foo(x: uint256)-> bytes32:
+    return blockhash(x)
+    """
+        ),
+        StateAccessViolation,
+    )

vyper/builtins/_signatures.py

@@ -6,6 +6,7 @@
 from vyper.codegen.expr import Expr
 from vyper.codegen.ir_node import IRnode
 from vyper.exceptions import CompilerPanic, TypeMismatch
+from vyper.semantics.analysis.base import StateMutability
 from vyper.semantics.analysis.utils import get_exact_type_from_node, validate_expected_type
 from vyper.semantics.types import TYPE_T, KwargSettings, VyperType
 from vyper.semantics.types.utils import type_from_annotation
@@ -77,6 +78,7 @@ def decorator_fn(self, node, context):
 class BuiltinFunction:
     _has_varargs = False
     _kwargs: Dict[str, KwargSettings] = {}
+    mutability = StateMutability.PURE
 
     # helper function to deal with TYPE_DEFINITIONs
     def _validate_single(self, arg, expected_type):

vyper/builtins/functions.py

@@ -51,7 +51,7 @@
     UnfoldableNode,
     ZeroDivisionException,
 )
-from vyper.semantics.analysis.base import VarInfo
+from vyper.semantics.analysis.base import StateMutability, VarInfo
 from vyper.semantics.analysis.utils import (
     get_common_types,
     get_exact_type_from_node,
@@ -1256,6 +1256,7 @@ class BlockHash(BuiltinFunction):
     _id = "blockhash"
     _inputs = [("block_num", UINT256_T)]
     _return_type = BYTES32_T
+    mutability = StateMutability.VIEW
 
     @process_inputs
     def build_IR(self, expr, args, kwargs, contact):

vyper/semantics/analysis/local.py

@@ -3,6 +3,7 @@
 from vyper import ast as vy_ast
 from vyper.ast.metadata import NodeMetadata
 from vyper.ast.validation import validate_call_args
+from vyper.builtins._signatures import BuiltinFunction
 from vyper.exceptions import (
     ExceptionList,
     FunctionDeclarationException,
@@ -203,9 +204,20 @@ def __init__(
             ]
             node_list.extend(standalone_self)  # type: ignore
 
+            # Add references to builtin functions reading from the chain's state
+            # TODO Fix circular import
+            from vyper.builtins.functions import BUILTIN_FUNCTIONS
+
+            builtin_fns = fn_node.get_descendants(vy_ast.Name, {"id": set(BUILTIN_FUNCTIONS)})
+
+            node_list.extend(builtin_fns)  # type: ignore
+
             for node in node_list:
                 t = node._metadata.get("type")
-                if isinstance(t, ContractFunctionT) and t.mutability == StateMutability.PURE:
+                if (
+                    isinstance(t, (BuiltinFunction, ContractFunctionT))
+                    and t.mutability == StateMutability.PURE
+                ):
                     # allowed
                     continue
                 raise StateAccessViolation(