patch 9.1.0523: Vim9: cannot downcast an object
Commit:
https://github.com/vim/vim/commit/50d485432c61cae4fea776d26bb051c270f79881
Author: LemonBoy <thatle...@gmail.com>
Date: Thu Jul 4 17:03:17 2024 +0200
patch 9.1.0523: Vim9: cannot downcast an object
Problem: Vim9: cannot downcast an object (Ernie Rael)
Solution: Fix class downcasting issue (LemonBoy).
When casting an object from one class to another the target type may be
a subclass (downcast) or superclass (upcast) of the source one.
Upcasts require a runtime type check to be emitted.
Add a disassembly test.
fixes: #13244
closes: #15079
Signed-off-by: LemonBoy <thatle...@gmail.com>
Signed-off-by: Yegappan Lakshmanan <yegap...@yahoo.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>
diff --git a/src/structs.h b/src/structs.h
index 7e21f0fc8..63092115b 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -4902,7 +4902,8 @@ typedef enum {
WT_MEMBER,
WT_METHOD, // object method
WT_METHOD_ARG, // object method argument type
- WT_METHOD_RETURN // object method return type
+ WT_METHOD_RETURN, // object method return type
+ WT_CAST, // type cast
} wherekind_T;
// Struct used to pass the location of a type check. Used in error messages to
diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index 8e328c2ee..13e8ea6e0 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -10871,4 +10871,21 @@ def Test_class_member_init_typecheck()
v9.CheckScriptFailure(lines, 'E1012: Type mismatch; expected string but got
number', 6)
enddef
+def Test_class_cast()
+ var lines =<< trim END
+ vim9script
+ class A
+ endclass
+ class B extends A
+ var mylen: number
+ endclass
+ def F(o: A): number
+ return (<B>o).mylen
+ enddef
+
+ defcompile F
+ END
+ v9.CheckScriptSuccess(lines)
+enddef
+
" vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker
diff --git a/src/testdir/test_vim9_disassemble.vim
b/src/testdir/test_vim9_disassemble.vim
index 89dcceed5..7746b23b4 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -1761,6 +1761,74 @@ def Test_disassemble_typecast()
instr)
enddef
+def Test_disassemble_object_cast()
+ # Downcasting.
+ var lines =<< trim END
+ vim9script
+ class A
+ endclass
+ class B extends A
+ var mylen: number
+ endclass
+ def F(o: A): number
+ return (<B>o).mylen
+ enddef
+
+ g:instr = execute('disassemble F')
+ END
+ v9.CheckScriptSuccess(lines)
+ assert_match('\<SNR>\d*_F\_s*' ..
+ 'return (<B>o).mylen\_s*' ..
+ '0 LOAD arg\[-1\]\_s*' ..
+ '1 CHECKTYPE object<B> stack\[-1\]\_s*' ..
+ '2 OBJ_MEMBER 0\_s*' ..
+ '3 RETURN\_s*',
+ g:instr)
+
+ # Upcasting.
+ lines =<< trim END
+ vim9script
+ class A
+ var mylen: number
+ endclass
+ class B extends A
+ endclass
+ def F(o: B): number
+ return (<A>o).mylen
+ enddef
+
+ g:instr = execute('disassemble F')
+ END
+ v9.CheckScriptSuccess(lines)
+ assert_match('\<SNR>\d*_F\_s*' ..
+ 'return (<A>o).mylen\_s*' ..
+ '0 LOAD arg\[-1\]\_s*' ..
+ '1 OBJ_MEMBER 0\_s*' ..
+ '2 RETURN\_s*',
+ g:instr)
+
+ # Casting, type is not statically known.
+ lines =<< trim END
+ vim9script
+ class A
+ endclass
+ class B extends A
+ endclass
+ def F(o: any): any
+ return <A>o
+ enddef
+
+ g:instr = execute('disassemble F')
+ END
+ v9.CheckScriptSuccess(lines)
+ assert_match('\<SNR>\d*_F\_s*' ..
+ 'return <A>o\_s*' ..
+ '0 LOAD arg\[-1\]\_s*' ..
+ '1 CHECKTYPE object<A> stack\[-1\]\_s*' ..
+ '2 RETURN\_s*',
+ g:instr)
+enddef
+
def s:Computing()
var nr = 3
var nrres = nr + 7
diff --git a/src/version.c b/src/version.c
index 249d1c549..6588f2f9a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 523,
/**/
522,
/**/
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 61fefa767..ea305b7b3 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -522,6 +522,8 @@ use_typecheck(type_T *actual, type_T *expected)
(actual->tt_member == &t_void)
== (expected->tt_member == &t_void))))
return TRUE;
+ if (actual->tt_type == VAR_OBJECT && expected->tt_type == VAR_OBJECT)
+ return TRUE;
if ((actual->tt_type == VAR_LIST || actual->tt_type == VAR_DICT)
&& actual->tt_type == expected->tt_type)
// This takes care of a nested list or dict.
diff --git a/src/vim9expr.c b/src/vim9expr.c
index 8c412b876..7af8bd63b 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -2836,12 +2836,13 @@ compile_expr8(char_u **arg, cctx_T *cctx, ppconst_T
*ppconst)
type_T *actual;
where_T where = WHERE_INIT;
+ where.wt_kind = WT_CAST;
generate_ppconst(cctx, ppconst);
actual = get_type_on_stack(cctx, 0);
if (check_type_maybe(want_type, actual, FALSE, where) != OK)
{
- if (need_type(actual, want_type, FALSE,
- -1, 0, cctx, FALSE, FALSE) == FAIL)
+ if (need_type_where(actual, want_type, FALSE, -1, where, cctx,
FALSE, FALSE)
+ == FAIL)
return FAIL;
}
}
diff --git a/src/vim9type.c b/src/vim9type.c
index ffdf7facb..a1571218f 100644
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -934,6 +934,7 @@ type_mismatch_where(type_T *expected, type_T *actual,
where_T where)
semsg(_(e_argument_nr_type_mismatch_expected_str_but_got_str_in_str),
where.wt_index, typename1, typename2,
where.wt_func_name);
break;
+ case WT_CAST:
case WT_UNKNOWN:
if (where.wt_func_name == NULL)
semsg(_(e_type_mismatch_expected_str_but_got_str),
@@ -1090,7 +1091,15 @@ check_type_maybe(
ret = FAIL;
}
else if (!class_instance_of(actual->tt_class, expected->tt_class))
- ret = FAIL;
+ {
+ // Check if this is an up-cast, if so we'll have to check the
type at
+ // runtime.
+ if (where.wt_kind == WT_CAST &&
+ class_instance_of(expected->tt_class, actual->tt_class))
+ ret = MAYBE;
+ else
+ ret = FAIL;
+ }
}
if (ret == FAIL && give_msg)
--
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