go/test/fixedbugs/bug175.go

// errorcheck

// Copyright 2009 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.

package main

func f() (int, bool) { return 0, true }

func main() {
	x, y := f(), 2 // ERROR "multi|2-valued"
	_, _ = x, y
}
test: use testlib (second 100) X ,s;^// \$G (\$D/)?\$F\.go $;// compile;g X ,s;^// \$G (\$D/)?\$F\.go && \$L \$F\.\$A $;// build;g X ,s;^// \$G (\$D/)?\$F\.go && \$L \$F\.\$A && \./\$A\.out $;// run;g X ,s;^// errchk \$G( -e)? (\$D/)?\$F\.go $;// errorcheck;g R=golang-dev CC=golang-dev https://golang.org/cl/5673078 2012-02-16 21:49:30 -07:00			`// errorcheck`
multiple return in := bug R=ken OCL=32253 CL=32253 2009-07-27 17:59:10 -06:00
			`// Copyright 2009 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.`

			`package main`

			`func f() (int, bool) { return 0, true }`

			`func main() {`
cmd/compile/internal/types2: avoid "declared but not used" errors for invalid code Agressively mark all LHS variables in assignments as used if there is any error in the (entire) assignment. This reduces the number of spurious "declared but not used" errors in programs that are invalid in the first place. This behavior is closer to the behavior of the compiler's original type checker (types1) and lets us remove lines of the form "_ = variable" just to satisfy test cases. It also makes more important errors visible by not crowding them out. Remove the Checker.useLHS function and use Checker.use instead: useLHS didn't evaluate top-level variables, but we actually want them to be evaluated in an error scenario so that they are getting used (and thus we don't get the "declared but not used" error). Fixes #42937. Change-Id: Idda460f6b81c66735bf9fd597c54188949bf12b8 Reviewed-on: https://go-review.googlesource.com/c/go/+/351730 Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Findley <rfindley@google.com> 2021-09-22 22:57:19 -06:00			`x, y := f(), 2 // ERROR "multi\|2-valued"`
go/types, types2: refactor initVars As with changes in prior CLs, we don't suppress legitimate "declared but not used" errors anymore simply because the respective variables are used in incorrect assignments, unrelated to the variables in question. Adjust several (ancient) tests accordingly. Change-Id: I5826393264d9d8085c64777a330d4efeb735dd2d Reviewed-on: https://go-review.googlesource.com/c/go/+/478716 Reviewed-by: Robert Griesemer <gri@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com> Run-TryBot: Robert Griesemer <gri@google.com> 2023-03-22 16:04:35 -06:00			`_, _ = x, y`
multiple return in := bug R=ken OCL=32253 CL=32253 2009-07-27 17:59:10 -06:00			`}`