cmd/compile: suppress callsite signatures if any type is unknown

Fixes #19012.

Fallback to return signatures without detailed types.
These error message will be of the form of issue:
* https://golang.org/issues/4215
* https://golang.org/issues/6750

So:
func f(x int, y uint) {
    return x > y
}

f(10, "a" < 3)

will give errors:
too many errors to return
too many arguments in call to f

instead of:

too many errors to return
  have (<T>)
  want ()
too many arguments in call to f
  have (number, <T>)
  want (number, number)

Change-Id: I680abc7cdd8444400e234caddf3ff49c2d69f53d
Reviewed-on: https://go-review.googlesource.com/36806
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Emmanuel Odeke 2017-02-10 23:41:53 -07:00 committed by Robert Griesemer
parent ffb3b3698c
commit 19d2061d50
2 changed files with 47 additions and 5 deletions

View file

@ -2700,17 +2700,18 @@ out:
notenough:
if n == nil || !n.Diag {
details := errorDetails(nl, tstruct, isddd)
if call != nil {
// call is the expression being called, not the overall call.
// Method expressions have the form T.M, and the compiler has
// rewritten those to ONAME nodes but left T in Left.
if call.Op == ONAME && call.Left != nil && call.Left.Op == OTYPE {
yyerror("not enough arguments in call to method expression %v\n\thave %s\n\twant %v", call, nl.retsigerr(isddd), tstruct)
yyerror("not enough arguments in call to method expression %v%s", call, details)
} else {
yyerror("not enough arguments in call to %v\n\thave %s\n\twant %v", call, nl.retsigerr(isddd), tstruct)
yyerror("not enough arguments in call to %v%s", call, details)
}
} else {
yyerror("not enough arguments to %v\n\thave %s\n\twant %v", op, nl.retsigerr(isddd), tstruct)
yyerror("not enough arguments to %v%s", op, details)
}
if n != nil {
n.Diag = true
@ -2720,14 +2721,30 @@ notenough:
goto out
toomany:
details := errorDetails(nl, tstruct, isddd)
if call != nil {
yyerror("too many arguments in call to %v\n\thave %s\n\twant %v", call, nl.retsigerr(isddd), tstruct)
yyerror("too many arguments in call to %v%s", call, details)
} else {
yyerror("too many arguments to %v\n\thave %s\n\twant %v", op, nl.retsigerr(isddd), tstruct)
yyerror("too many arguments to %v%s", op, details)
}
goto out
}
func errorDetails(nl Nodes, tstruct *Type, isddd bool) string {
// If we don't know any type at a call site, let's suppress any return
// message signatures. See Issue https://golang.org/issues/19012.
if tstruct == nil {
return ""
}
// If any node has an unknown type, suppress it as well
for _, n := range nl.Slice() {
if n.Type == nil {
return ""
}
}
return fmt.Sprintf("\n\thave %s\n\twant %v", nl.retsigerr(isddd), tstruct)
}
// sigrepr is a type's representation to the outside world,
// in string representations of return signatures
// e.g in error messages about wrong arguments to return.

View file

@ -0,0 +1,25 @@
// 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.
// Issue 19012: if we have any unknown type at a call site,
// we must ensure that we return to the user a suppressed
// error message saying instead of including <T> in
// the message.
package main
func f(x int, y uint) {
if true {
return "a" > 10 // ERROR "^too many arguments to return$" "."
}
return "gopher" == true, 10 // ERROR "^too many arguments to return$" "."
}
func main() {
f(2, 3 < "x", 10) // ERROR "^too many arguments in call to f$" "."
f(10, 10, "a") // ERROR "too many arguments in call to f\n\thave \(number, number, string\)\n\twant \(int, uint\)"
}