diff --git a/py/emitcommon.c b/py/emitcommon.c index c1780d2db9..647430232a 100644 --- a/py/emitcommon.c +++ b/py/emitcommon.c @@ -44,9 +44,14 @@ qstr_short_t mp_emit_common_use_qstr(mp_emit_common_t *emit, qstr qst) { void mp_emit_common_get_id_for_modification(scope_t *scope, qstr qst) { // name adding/lookup id_info_t *id = scope_find_or_add_id(scope, qst, ID_INFO_KIND_GLOBAL_IMPLICIT); - if (SCOPE_IS_FUNC_LIKE(scope->kind) && id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) { - // rebind as a local variable - id->kind = ID_INFO_KIND_LOCAL; + if (id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) { + if (SCOPE_IS_FUNC_LIKE(scope->kind)) { + // rebind as a local variable + id->kind = ID_INFO_KIND_LOCAL; + } else { + // mark this as assigned, to prevent it from being closed over + id->kind = ID_INFO_KIND_GLOBAL_IMPLICIT_ASSIGNED; + } } } @@ -57,7 +62,7 @@ void mp_emit_common_id_op(emit_t *emit, const mp_emit_method_table_id_ops_t *emi assert(id != NULL); // call the emit backend with the correct code - if (id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT) { + if (id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT || id->kind == ID_INFO_KIND_GLOBAL_IMPLICIT_ASSIGNED) { emit_method_table->global(emit, qst, MP_EMIT_IDOP_GLOBAL_NAME); } else if (id->kind == ID_INFO_KIND_GLOBAL_EXPLICIT) { emit_method_table->global(emit, qst, MP_EMIT_IDOP_GLOBAL_GLOBAL); diff --git a/py/scope.h b/py/scope.h index 5006deadea..b781dde427 100644 --- a/py/scope.h +++ b/py/scope.h @@ -32,6 +32,7 @@ typedef enum { ID_INFO_KIND_UNDECIDED, ID_INFO_KIND_GLOBAL_IMPLICIT, + ID_INFO_KIND_GLOBAL_IMPLICIT_ASSIGNED, ID_INFO_KIND_GLOBAL_EXPLICIT, ID_INFO_KIND_LOCAL, // in a function f, written and only referenced by f ID_INFO_KIND_CELL, // in a function f, read/written by children of f diff --git a/tests/basics/scope_class.py b/tests/basics/scope_class.py new file mode 100644 index 0000000000..9c519695dc --- /dev/null +++ b/tests/basics/scope_class.py @@ -0,0 +1,77 @@ +# test scoping rules that involve a class + +# the inner A.method should be independent to the local function called method +def test1(): + def method(): + pass + + class A: + def method(): + pass + + print(hasattr(A, "method")) + print(hasattr(A(), "method")) + + +test1() + + +# the inner A.method is a closure and overrides the local function called method +def test2(): + def method(): + return "outer" + + class A: + nonlocal method + + def method(): + return "inner" + + print(hasattr(A, "method")) + print(hasattr(A(), "method")) + return method() # this is actually A.method + + +print(test2()) + + +# a class body will capture external variables by value (not by reference) +def test3(x): + class A: + local = x + + x += 1 + return x, A.local + + +print(test3(42)) + + +# assigning to a variable in a class will implicitly prevent it from closing over a variable +def test4(global_): + class A: + local = global_ # fetches outer global_ + global_ = "global2" # creates class attribute + + global_ += 1 # updates local variable + return global_, A.local, A.global_ + + +global_ = "global" +print(test4(42), global_) + + +# methods within a class can close over variables outside the class +def test5(x): + def closure(): + return x + + class A: + def method(): + return x, closure() + + closure = lambda: x + 1 # change it after A has been created + return A + + +print(test5(42).method())