From 3218b1aa6fffef560147bcbbcb313a5c8a5e0d76 Mon Sep 17 00:00:00 2001 From: Alberto Donizetti Date: Thu, 13 Apr 2017 10:42:16 +0200 Subject: [PATCH] cmd/compile: only print one error for bad-type literal in assignment Fixes #8438 Change-Id: Ib43cdcdc962a8d9e14faf984bc859a92ba1eb517 Reviewed-on: https://go-review.googlesource.com/40531 Reviewed-by: Robert Griesemer --- src/cmd/compile/internal/gc/subr.go | 4 +++- test/fixedbugs/issue8438.go | 17 +++++++++++++++++ test/interface/explicit.go | 3 +-- 3 files changed, 21 insertions(+), 3 deletions(-) create mode 100644 test/fixedbugs/issue8438.go diff --git a/src/cmd/compile/internal/gc/subr.go b/src/cmd/compile/internal/gc/subr.go index ff2d88614b1..b52b4e4e69d 100644 --- a/src/cmd/compile/internal/gc/subr.go +++ b/src/cmd/compile/internal/gc/subr.go @@ -982,7 +982,9 @@ func assignconvfn(n *Node, t *types.Type, context func() string) *Node { var why string op := assignop(n.Type, t, &why) if op == 0 { - yyerror("cannot use %L as type %v in %s%s", n, t, context(), why) + if !old.Diag() { + yyerror("cannot use %L as type %v in %s%s", n, t, context(), why) + } op = OCONV } diff --git a/test/fixedbugs/issue8438.go b/test/fixedbugs/issue8438.go new file mode 100644 index 00000000000..b28025cdac4 --- /dev/null +++ b/test/fixedbugs/issue8438.go @@ -0,0 +1,17 @@ +// errorcheck + +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Check that we don't print duplicate errors for string -> +// array-literal conversion + +package main + +func main() { + _ = []byte{"foo"} // ERROR "cannot convert" + _ = []int{"foo"} // ERROR "cannot convert" + _ = []rune{"foo"} // ERROR "cannot convert" + _ = []string{"foo"} // OK +} diff --git a/test/interface/explicit.go b/test/interface/explicit.go index b10d02f2485..3c449b13ada 100644 --- a/test/interface/explicit.go +++ b/test/interface/explicit.go @@ -53,7 +53,7 @@ func main() { i2 = I2(i) // ERROR "invalid|missing N method" e = E(t) // ok - t = T(e) // ERROR "need explicit|need type assertion|incompatible" "as type [*]T" + t = T(e) // ERROR "need explicit|need type assertion|incompatible" } type M interface { @@ -81,7 +81,6 @@ var m2 M = jj // ERROR "incompatible|wrong type for M method" var m3 = M(ii) // ERROR "invalid|missing" var m4 = M(jj) // ERROR "invalid|wrong type for M method" - type B1 interface { _() // ERROR "methods must have a unique non-blank name" }