fix[codegen]: relax the filter for augassign oob check

tests/functional/codegen/features/test_assignment.py

@@ -1,5 +1,6 @@
 import pytest
 
+from vyper.evm.opcodes import version_check
 from vyper.exceptions import CodegenPanic, ImmutableViolation, InvalidType, TypeMismatch
 
 
@@ -103,6 +104,71 @@ def test_augassign_oob(get_contract, tx_failed, source):
     "source",
     [
         """
+@external
+def entry() -> DynArray[uint256, 2]:
+    a: DynArray[uint256, 2] = [1, 1]
+    a[1] += a[1]
+    return a
+    """,
+        """
+@external
+def entry() -> DynArray[uint256, 2]:
+    a: uint256 = 1
+    a += a
+    b: DynArray[uint256, 2] = [a, a]
+    b[0] -= b[0]
+    b[0] += b[1] // 2
+    return b
+    """,
+        """
+a: DynArray[uint256, 2]
+
+def read() -> uint256:
+    return self.a[1]
+
+@external
+def entry() -> DynArray[uint256, 2]:
+    self.a = [1, 1]
+    self.a[1] += self.read()
+    return self.a
+    """,
+        """
+interface Foo:
+    def foo() -> uint256: nonpayable
+
+@external
+def foo() -> uint256:
+    return 1
+
+@external
+def entry() -> DynArray[uint256, 2]:
+    # memory variable, can't be overwritten by extcall, so there
+    # is no panic
+    a: DynArray[uint256, 2] = [1, 1]
+    a[1] += extcall Foo(self).foo()
+    return a
+    """,
+        """
+interface Foo:
+    def foo() -> uint256: nonpayable
+
+def get_foo() -> uint256:
+    return extcall Foo(self).foo()
+
+@external
+def foo() -> uint256:
+    return 1
+
+@external
+def entry() -> DynArray[uint256, 2]:
+    # memory variable, can't be overwritten by extcall, so there
+    # is no panic
+    a: DynArray[uint256, 2] = [1, 1]
+    # extcall hidden inside internal function
+    a[1] += self.get_foo()
+    return a
+    """,
+        """
 a: public(DynArray[uint256, 2])
 
 interface Foo:
@@ -115,57 +181,78 @@ def foo() -> uint256:
 @external
 def entry() -> DynArray[uint256, 2]:
     self.a = [1, 1]
-    # panics due to staticcall
     self.a[1] += staticcall Foo(self).foo()
     return self.a
-    """
+    """,
     ],
 )
-@pytest.mark.xfail(strict=True, raises=CodegenPanic)
-def test_augassign_rhs_references_lhs(get_contract, tx_failed, source):
-    # xfail here (with panic):
+def test_augassign_rhs_references_lhs2(get_contract, source):
     c = get_contract(source)
-
     assert c.entry() == [1, 2]
 
 
+@pytest.mark.requires_evm_version("cancun")
+def test_augassign_rhs_references_lhs_transient(get_contract):
+    source = """
+x: transient(DynArray[uint256, 2])
+
+def read() -> uint256:
+    return self.x[0]
+
+@external
+def entry() -> DynArray[uint256, 2]:
+    self.x = [1, 1]
+    # test augassign with state read hidden behind function call
+    self.x[0] += self.read()
+    # augassign with direct state read
+    self.x[1] += self.x[0]
+    return self.x
+    """
+    c = get_contract(source)
+
+    assert c.entry() == [2, 3]
+
+
 @pytest.mark.parametrize(
     "source",
     [
         """
+x: transient(DynArray[uint256, 2])
+
+def write() -> uint256:
+    return self.x.pop()
+
 @external
 def entry() -> DynArray[uint256, 2]:
-    a: DynArray[uint256, 2] = [1, 1]
-    a[1] += a[1]
-    return a
-    """,
-        """
-@external
-def entry() -> DynArray[uint256, 2]:
-    a: uint256 = 1
-    a += a
-    b: DynArray[uint256, 2] = [a, a]
-    b[0] -= b[0]
-    b[0] += b[1] // 2
-    return b
+    self.x = [1, 1]
+    # hide state write behind function call
+    self.x[1] += self.write()
+    return self.x
     """,
         """
-a: DynArray[uint256, 2]
-
-def read() -> uint256:
-    return self.a[1]
+x: transient(DynArray[uint256, 2])
 
 @external
 def entry() -> DynArray[uint256, 2]:
-    self.a = [1, 1]
-    self.a[1] += self.read()
-    return self.a
+    self.x = [1, 1]
+    # direct state write
+    self.x[1] += self.x.pop()
+    return self.x
     """,
     ],
 )
-def test_augassign_rhs_references_lhs2(get_contract, source):
+@pytest.mark.xfail(strict=True, raises=CodegenPanic)
+def test_augassign_rhs_references_lhs_transient2(get_contract, tx_failed, source):
+    if not version_check(begin="cancun"):
+        # no transient available before cancun
+        pytest.skip()
+
+    # xfail here (with panic):
     c = get_contract(source)
-    assert c.entry() == [1, 2]
+
+    # not reached until the panic is fixed
+    with tx_failed(c):
+        c.entry()
 
 
 @pytest.mark.parametrize(

vyper/codegen/ir_node.py

@@ -498,6 +498,18 @@ def contains_risky_call(self):
 
         return ret
 
+    @cached_property
+    def contains_writeable_call(self):
+        ret = self.value in ("call", "delegatecall", "create", "create2")
+
+        for arg in self.args:
+            ret |= arg.contains_writeable_call
+
+        if getattr(self, "is_self_call", False):
+            ret |= self.invoked_function_ir.func_ir.contains_writeable_call
+
+        return ret
+
     @cached_property
     def contains_self_call(self):
         return getattr(self, "is_self_call", False) or any(x.contains_self_call for x in self.args)

vyper/codegen/stmt.py

@@ -293,7 +293,9 @@ def parse_AugAssign(self):
             if var.typ._is_prim_word:
                 continue
             # oob - GHSA-4w26-8p97-f4jp
-            if var in right.variable_writes or right.contains_risky_call:
+            if var in right.variable_writes or (
+                var.is_state_variable() and right.contains_writeable_call
+            ):
                 raise CodegenPanic("unreachable")
 
         with target.cache_when_complex("_loc") as (b, target):

vyper/semantics/analysis/base.py

@@ -205,6 +205,7 @@ def set_position(self, position: VarOffset) -> None:
         assert isinstance(position, VarOffset)  # sanity check
         self.position = position
 
+    # TODO: convert to property
     def is_state_variable(self):
         non_state_locations = (DataLocation.UNSET, DataLocation.MEMORY, DataLocation.CALLDATA)
         # `self` gets a VarInfo, but it is not considered a state