cmd/compile/types2, go/types: add position for "have" in failed inter…

…face satisfaction With this change, we shall now see: *myS does not implement S (wrong type for DoSomething method) have DoSomething() (string, error) at ./main.go:9:14 want DoSomething() (int, error) instead of previously: *myS does not implement S (wrong type for DoSomething method) have DoSomething() (string, error) want DoSomething() (int, error) Fixes #42841 Fixes #45813 Change-Id: I66990929e39b0d36f2e91da0d92f60586a9b84e5 Reviewed-on: https://go-review.googlesource.com/c/go/+/373634 Trust: Robert Findley <[email protected]> Trust: Emmanuel Odeke <[email protected]> Run-TryBot: Emmanuel Odeke <[email protected]> TryBot-Result: Gopher Robot <[email protected]> Reviewed-by: Robert Griesemer <[email protected]>
cloudflare · Jan 12, 2022 · 8070e70 · 8070e70
1 parent 1ee70da
commit 8070e70
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Showing 4 changed files with 20 additions and 19 deletions.
diff --git a/src/cmd/compile/internal/types2/lookup.go b/src/cmd/compile/internal/types2/lookup.go
@@ -428,18 +428,18 @@ func (check *Checker) missingMethodReason(V, T Type, m, wrongType *Func) string
  if wrongType != nil {
  if Identical(m.typ, wrongType.typ) {
  if m.Name() == wrongType.Name() {
- r = check.sprintf("(%s has pointer receiver)", mname)
+ r = check.sprintf("(%s has pointer receiver) at %s", mname, wrongType.Pos())
  } else {
- r = check.sprintf("(missing %s)\n\t\thave %s^^%s\n\t\twant %s^^%s",
- mname, wrongType.Name(), wrongType.typ, m.Name(), m.typ)
+ r = check.sprintf("(missing %s)\n\t\thave %s^^%s at %s\n\t\twant %s^^%s",
+ mname, wrongType.Name(), wrongType.typ, wrongType.Pos(), m.Name(), m.typ)
  }
  } else {
  if check.conf.CompilerErrorMessages {
- r = check.sprintf("(wrong type for %s)\n\t\thave %s^^%s\n\t\twant %s^^%s",
- mname, wrongType.Name(), wrongType.typ, m.Name(), m.typ)
+ r = check.sprintf("(wrong type for %s)\n\t\thave %s^^%s at %s\n\t\twant %s^^%s",
+ mname, wrongType.Name(), wrongType.typ, wrongType.Pos(), m.Name(), m.typ)
  } else {
- r = check.sprintf("(wrong type for %s: have %s, want %s)",
- mname, wrongType.typ, m.typ)
+ r = check.sprintf("(wrong type for %s)\n\thave %s at %s\n\twant %s",
+ mname, wrongType.typ, wrongType.Pos(), m.typ)
  }
  }
  // This is a hack to print the function type without the leading

diff --git a/src/cmd/compile/internal/types2/testdata/check/issues.src b/src/cmd/compile/internal/types2/testdata/check/issues.src
@@ -137,7 +137,7 @@ func issue10260() {
  T1{}.foo /* ERROR cannot call pointer method foo on T1 */ ()
  x.Foo /* ERROR "x.Foo undefined \(type I1 has no field or method Foo, but does have foo\)" */ ()
 
- _ = i2. /* ERROR impossible type assertion: i2.\(\*T1\)\n\t\*T1 does not implement I2 \(wrong type for method foo: have func\(\), want func\(x int\)\) */ (*T1)
+ _ = i2. /* ERROR impossible type assertion: i2.\(\*T1\)\n\t\*T1 does not implement I2 \(wrong type for method foo\)\n\thave func\(\) at \w+.+\d+.\d+\n\twant func\(x int\) */ (*T1)
 
  i1 = i0 /* ERROR cannot use .* missing method foo */
  i1 = t0 /* ERROR cannot use .* missing method foo */

diff --git a/src/go/types/lookup.go b/src/go/types/lookup.go
@@ -400,20 +400,21 @@ func (check *Checker) missingMethodReason(V, T Type, m, wrongType *Func) string
  mname = "method " + m.Name()
  }
  if wrongType != nil {
+ pos := check.fset.Position(wrongType.Pos())
  if Identical(m.typ, wrongType.typ) {
  if m.Name() == wrongType.Name() {
- r = check.sprintf("(%s has pointer receiver)", mname)
+ r = check.sprintf("(%s has pointer receiver) at %s", mname, pos)
  } else {
- r = check.sprintf("(missing %s)\n\t\thave %s^^%s\n\t\twant %s^^%s",
- mname, wrongType.Name(), wrongType.typ, m.Name(), m.typ)
+ r = check.sprintf("(missing %s)\n\t\thave %s^^%s at %s\n\t\twant %s^^%s",
+ mname, wrongType.Name(), wrongType.typ, pos, m.Name(), m.typ)
  }
  } else {
  if compilerErrorMessages {
- r = check.sprintf("(wrong type for %s)\n\t\thave %s^^%s\n\t\twant %s^^%s",
- mname, wrongType.Name(), wrongType.typ, m.Name(), m.typ)
+ r = check.sprintf("(wrong type for %s)\n\t\thave %s^^%s at %s\n\t\twant %s^^%s",
+ mname, wrongType.Name(), wrongType.typ, pos, m.Name(), m.typ)
  } else {
- r = check.sprintf("(wrong type for %s: have %s, want %s)",
- mname, wrongType.typ, m.typ)
+ r = check.sprintf("(wrong type for %s)\n\thave %s at %s\nwant %s",
+ mname, wrongType.typ, pos, m.typ)
  }
  }
  // This is a hack to print the function type without the leading

diff --git a/test/fixedbugs/issue48471.go b/test/fixedbugs/issue48471.go
@@ -29,12 +29,12 @@ func g() {
  var i I
  i = new(T) // ERROR "cannot use new\(T\) \(.*type \*T\) as type I in assignment:\n\t\*T does not implement I \(missing M method\)"
  i = I(new(T)) // ERROR "cannot convert new\(T\) \(.*type \*T\) to type I:\n\t\*T does not implement I \(missing M method\)"
- i = new(T2) // ERROR "cannot use new\(T2\) \(.*type \*T2\) as type I in assignment:\n\t\*T2 does not implement I \(missing M method\)\n\t\thave m\(int\)\n\t\twant M\(int\)"
- i = new(T3) // ERROR "cannot use new\(T3\) \(.*type \*T3\) as type I in assignment:\n\t\*T3 does not implement I \(wrong type for M method\)\n\t\thave M\(string\)\n\t\twant M\(int\)"
+ i = new(T2) // ERROR "cannot use new\(T2\) \(.*type \*T2\) as type I in assignment:\n\t\*T2 does not implement I \(missing M method\)\n\t\thave m\(int\) at \w+.+\d.\d+\n\t\twant M\(int\)"
+ i = new(T3) // ERROR "cannot use new\(T3\) \(.*type \*T3\) as type I in assignment:\n\t\*T3 does not implement I \(wrong type for M method\)\n\t\thave M\(string\) at \w+.+\d.\d+\n\t\twant M\(int\)"
  i = T4{} // ERROR "cannot use T4\{\} \(.*type T4\) as type I in assignment:\n\tT4 does not implement I \(M method has pointer receiver\)"
  i = new(I) // ERROR "cannot use new\(I\) \(.*type \*I\) as type I in assignment:\n\t\*I does not implement I \(type \*I is pointer to interface, not interface\)"
- _ = i.(*T2) // ERROR "impossible type assertion: i.\(\*T2\)\n\t\*T2 does not implement I \(missing M method\)\n\t\thave m\(int\)\n\t\twant M\(int\)"
- _ = i.(*T3) // ERROR "impossible type assertion: i.\(\*T3\)\n\t\*T3 does not implement I \(wrong type for M method\)\n\t\thave M\(string\)\n\t\twant M\(int\)"
+ _ = i.(*T2) // ERROR "impossible type assertion: i.\(\*T2\)\n\t\*T2 does not implement I \(missing M method\)\n\t\thave m\(int\) at \w+.+\d.\d+\n\t\twant M\(int\)"
+ _ = i.(*T3) // ERROR "impossible type assertion: i.\(\*T3\)\n\t\*T3 does not implement I \(wrong type for M method\)\n\t\thave M\(string\) at \w+.+\d.\d+\n\t\twant M\(int\)"
  var t *T4
  t = i // ERROR "cannot use i \(variable of type I\) as type \*T4 in assignment:\n\tneed type assertion"
  _ = i