From 638f0f69eda924c1478902a583703bae56e6803a Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Tue, 2 May 2023 09:52:40 -0300
Subject: [PATCH] checker: fix wrong error message about missing `shared` on
 parameter signature (fix #18087) (#18091)

---
 vlib/v/checker/fn.v                       |  6 ++---
 vlib/v/checker/tests/shared_param_err.out | 14 +++++++++++
 vlib/v/checker/tests/shared_param_err.vv  | 29 +++++++++++++++++++++++
 3 files changed, 46 insertions(+), 3 deletions(-)
 create mode 100644 vlib/v/checker/tests/shared_param_err.out
 create mode 100644 vlib/v/checker/tests/shared_param_err.vv

diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 3cbc1edd1..c72fe9bf5 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -1086,7 +1086,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 			}
 		} else {
 			if param.is_mut {
-				tok := call_arg.share.str()
+				tok := if param.typ.has_flag(.shared_f) { 'shared' } else { call_arg.share.str() }
 				c.error('function `${node.name}` parameter `${param.name}` is `${tok}`, so use `${tok} ${call_arg.expr}` instead',
 					call_arg.expr.pos())
 			} else {
@@ -1805,7 +1805,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 				}
 			} else {
 				if param_is_mut {
-					tok := arg.share.str()
+					tok := if param.typ.has_flag(.shared_f) { 'shared' } else { arg.share.str() }
 					c.error('method `${node.name}` parameter `${param.name}` is `${tok}`, so use `${tok} ${arg.expr}` instead',
 						arg.expr.pos())
 				} else {
@@ -2056,7 +2056,7 @@ fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 					}
 				} else {
 					if param.is_mut {
-						tok := arg.share.str()
+						tok := if param.typ.has_flag(.shared_f) { 'shared' } else { arg.share.str() }
 						c.error('method `${node.name}` parameter ${i + 1} is `${tok}`, so use `${tok} ${arg.expr}` instead',
 							arg.expr.pos())
 					} else {
diff --git a/vlib/v/checker/tests/shared_param_err.out b/vlib/v/checker/tests/shared_param_err.out
new file mode 100644
index 000000000..70bf5eb5f
--- /dev/null
+++ b/vlib/v/checker/tests/shared_param_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/shared_param_err.vv:23:12: error: method `g` parameter `c` is `shared`, so use `shared a` instead
+   21 |         x: 10
+   22 |     }
+   23 |     spawn a.g(a)
+      |               ^
+   24 |     spawn foo(a)
+   25 |
+vlib/v/checker/tests/shared_param_err.vv:24:12: error: function `foo` parameter `b` is `shared`, so use `shared a` instead
+   22 |     }
+   23 |     spawn a.g(a)
+   24 |     spawn foo(a)
+      |               ^
+   25 | 
+   26 |     rlock a {
diff --git a/vlib/v/checker/tests/shared_param_err.vv b/vlib/v/checker/tests/shared_param_err.vv
new file mode 100644
index 000000000..da587b990
--- /dev/null
+++ b/vlib/v/checker/tests/shared_param_err.vv
@@ -0,0 +1,29 @@
+struct St {
+mut:
+	x int
+	// data to be shared
+}
+
+fn (shared b St) g(shared c St) {
+	lock b {
+		b.x = 100
+	}
+}
+
+fn foo(shared b St) {
+	lock b {
+		b.x = 101
+	}
+}
+
+fn main() {
+	shared a := St{
+		x: 10
+	}
+	spawn a.g(a)
+	spawn foo(a)
+
+	rlock a {
+		println(a.x)
+	}
+}
-- 
2.39.5