From 4007c6cf89256dfe3c18a428cd5e67505bff1935 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Tue, 28 Mar 2023 20:00:08 +0800
Subject: [PATCH] checker: check generic struct infering error (#17802)

---
 vlib/v/checker/check_types.v                       |  3 +++
 vlib/v/checker/tests/generic_interface_err.out     |  6 ++++++
 vlib/v/checker/tests/generics_struct_infer_err.out |  7 +++++++
 vlib/v/checker/tests/generics_struct_infer_err.vv  | 11 +++++++++++
 vlib/v/checker/tests/generics_struct_init_err.out  |  4 ++--
 vlib/v/checker/tests/interface_generic_err.out     |  6 ++++++
 6 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 vlib/v/checker/tests/generics_struct_infer_err.out
 create mode 100644 vlib/v/checker/tests/generics_struct_infer_err.vv

diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index 2f12d5aaf5..da0f9d5aaf 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -793,6 +793,9 @@ fn (mut c Checker) infer_struct_generic_types(typ ast.Type, node ast.StructInit)
 					}
 				}
 			}
+			c.error('could not infer generic type `${gt_name}` in generic struct `${sym.name}[${generic_names.join(', ')}]`',
+				node.pos)
+			return concrete_types
 		}
 	}
 	return concrete_types
diff --git a/vlib/v/checker/tests/generic_interface_err.out b/vlib/v/checker/tests/generic_interface_err.out
index 5c197aefe0..007bc890f7 100644
--- a/vlib/v/checker/tests/generic_interface_err.out
+++ b/vlib/v/checker/tests/generic_interface_err.out
@@ -3,6 +3,12 @@ vlib/v/checker/tests/generic_interface_err.vv:10:1: warning: unused variable: `i
     9 | s := Struct{7}
    10 | i := Interface(s)
       | ^
+vlib/v/checker/tests/generic_interface_err.vv:9:6: error: could not infer generic type `T` in generic struct `Struct[T]`
+    7 | }
+    8 |
+    9 | s := Struct{7}
+      |      ~~~~~~~~~
+   10 | i := Interface(s)
 vlib/v/checker/tests/generic_interface_err.vv:10:6: error: can not find method `method` on `Struct`, needed for interface: `Interface`
     8 |
     9 | s := Struct{7}
diff --git a/vlib/v/checker/tests/generics_struct_infer_err.out b/vlib/v/checker/tests/generics_struct_infer_err.out
new file mode 100644
index 0000000000..d7fda8c1fd
--- /dev/null
+++ b/vlib/v/checker/tests/generics_struct_infer_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_struct_infer_err.vv:7:10: error: could not infer generic type `U` in generic struct `Foo[T, U]`
+    5 |
+    6 | fn main() {
+    7 |     st11 := Foo{
+      |             ~~~~
+    8 |         a: 'two'
+    9 |     }
diff --git a/vlib/v/checker/tests/generics_struct_infer_err.vv b/vlib/v/checker/tests/generics_struct_infer_err.vv
new file mode 100644
index 0000000000..800bbe3861
--- /dev/null
+++ b/vlib/v/checker/tests/generics_struct_infer_err.vv
@@ -0,0 +1,11 @@
+struct Foo[T, U] {
+	a T
+	b U
+}
+
+fn main() {
+	st11 := Foo{
+		a: 'two'
+	}
+	println(st11)
+}
diff --git a/vlib/v/checker/tests/generics_struct_init_err.out b/vlib/v/checker/tests/generics_struct_init_err.out
index b29871d11e..32e1c26f4f 100644
--- a/vlib/v/checker/tests/generics_struct_init_err.out
+++ b/vlib/v/checker/tests/generics_struct_init_err.out
@@ -1,8 +1,8 @@
-vlib/v/checker/tests/generics_struct_init_err.vv:67:23: error: could not infer generic type `T` in call to `call`
+vlib/v/checker/tests/generics_struct_init_err.vv:67:8: error: could not infer generic type `T` in generic struct `FnHolder2[T]`
    65 |     ret = holder_call_22(neg, 5)
    66 |     assert ret == -5
    67 |     ret = FnHolder2{neg}.call(6)
-      |                          ~~~~~~~
+      |           ~~~~~~~~~~~~~~
    68 |     assert ret == -6
    69 | }
 vlib/v/checker/tests/generics_struct_init_err.vv:22:7: error: generic struct init must specify type parameter, e.g. Foo[T]
diff --git a/vlib/v/checker/tests/interface_generic_err.out b/vlib/v/checker/tests/interface_generic_err.out
index 709993e1a8..bf888de203 100644
--- a/vlib/v/checker/tests/interface_generic_err.out
+++ b/vlib/v/checker/tests/interface_generic_err.out
@@ -3,6 +3,12 @@ vlib/v/checker/tests/interface_generic_err.vv:8:1: warning: unused variable: `wh
     7 | what := What{}
     8 | why := Why(what)
       | ~~~
+vlib/v/checker/tests/interface_generic_err.vv:7:9: error: could not infer generic type `T` in generic struct `What[T]`
+    5 |
+    6 | // no segfault without generic
+    7 | what := What{}
+      |         ~~~~~~
+    8 | why := Why(what)
 vlib/v/checker/tests/interface_generic_err.vv:8:8: error: could not infer generic type `T` in interface `Why`
     6 | // no segfault without generic
     7 | what := What{}