checker: check generic method receiver type mismatch (#16739)

vlib/v/checker/fn.v

@@ -215,10 +215,9 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 				c.error('optional or result type argument is not supported currently',
 					param.type_pos)
 			}
-			if !param.typ.is_ptr() { // value parameter, i.e. on stack - check for `[heap]`
 			arg_typ_sym := c.table.sym(param.typ)
 			if arg_typ_sym.info is ast.Struct {
-					if arg_typ_sym.info.is_heap { // set auto_heap to promote value parameter
+				if !param.typ.is_ptr() && arg_typ_sym.info.is_heap { // set auto_heap to promote value parameter
 					mut v := node.scope.find_var(param.name) or { continue }
 					v.is_auto_heap = true
 				}
@@ -240,7 +239,6 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 						param.type_pos)
 				}
 			}
-			}
 			// Ensure each generic type of the parameter was declared in the function's definition
 			if param.typ.has_flag(.generic) {
 				generic_names := c.table.generic_type_names(param.typ)

vlib/v/checker/tests/generics_method_receiver_type_err.out

@@ -1,7 +0,0 @@
-vlib/v/checker/tests/generics_method_receiver_type_err.vv:6:11: error: generic struct `Node` in fn declaration must specify the generic type names, e.g. Node[T]
-    4 | }
-    5 |
-    6 | pub fn (x Node) str() string {
-      |           ~~~~
-    7 |     return 'Value is : ${u16(x.val)}\nName is : $x.name'
-    8 | }

vlib/v/checker/tests/generics_method_receiver_type_err_a.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_method_receiver_type_err_a.vv:6:11: error: generic struct `Node` in fn declaration must specify the generic type names, e.g. Node[T]
+    4 | }
+    5 |
+    6 | pub fn (x Node) str() string {
+      |           ~~~~
+    7 |     return 'Value is : ${u16(x.val)}\nName is : $x.name'
+    8 | }

vlib/v/checker/tests/generics_method_receiver_type_err_b.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_method_receiver_type_err_b.vv:8:12: error: generic struct `ConsumableResources` in fn declaration must specify the generic type names, e.g. ConsumableResources[T]
+    6 |     used_resources map[T]Resources
+    7 | }
+    8 | pub fn (cr &ConsumableResources) get_total_resources() Resources {
+      |            ~~~~~~~~~~~~~~~~~~~~
+    9 |     return cr.total_resources
+   10 | }

vlib/v/checker/tests/generics_method_receiver_type_err_b.vv

@@ -0,0 +1,13 @@
+pub struct Resources{}
+
+pub struct ConsumableResources[T] {
+mut:
+	total_resources Resources
+	used_resources map[T]Resources
+}
+pub fn (cr &ConsumableResources) get_total_resources() Resources {
+	return cr.total_resources
+}
+
+fn main() {
+}