cmd/compile: fix type error reported on the wrong line

The 'Does not match' type error shoud be reported where
the function is called, not where the function is declared.

And fix the todo by gri of issue45985

Fixes #45985
Fixes #49800

Change-Id: I15aac44dd44f2a57c485a1c273fcd79db912c389
Reviewed-on: https://go-review.googlesource.com/c/go/+/362634
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/compile/internal/types2/infer.go b/src/cmd/compile/internal/types2/infer.go
index 4f85a5894cc0726feffeaa4d93ceb81d56257203..b203985b8d129027d75a8b16c10c54e7bc0307b5 100644 (file)
--- a/src/cmd/compile/internal/types2/infer.go
+++ b/src/cmd/compile/internal/types2/infer.go
@@ -60,7 +60,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeParam, targs []Type,
        // If we have type arguments, see how far we get with constraint type inference.
        if len(targs) > 0 && useConstraintTypeInference {
                var index int
-               targs, index = check.inferB(tparams, targs)
+               targs, index = check.inferB(pos, tparams, targs)
                if targs == nil || index < 0 {
                        return targs
                }
@@ -171,7 +171,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeParam, targs []Type,
        // Note that even if we don't have any type arguments, constraint type inference
        // may produce results for constraints that explicitly specify a type.
        if useConstraintTypeInference {
-               targs, index = check.inferB(tparams, targs)
+               targs, index = check.inferB(pos, tparams, targs)
                if targs == nil || index < 0 {
                        return targs
                }
@@ -209,7 +209,7 @@ func (check *Checker) infer(pos syntax.Pos, tparams []*TypeParam, targs []Type,
 
        // Again, follow up with constraint type inference.
        if useConstraintTypeInference {
-               targs, index = check.inferB(tparams, targs)
+               targs, index = check.inferB(pos, tparams, targs)
                if targs == nil || index < 0 {
                        return targs
                }
@@ -360,7 +360,7 @@ func (w *tpWalker) isParameterizedTypeList(list []Type) bool {
 // first type argument in that list that couldn't be inferred (and thus is nil). If all
 // type arguments were inferred successfully, index is < 0. The number of type arguments
 // provided may be less than the number of type parameters, but there must be at least one.
-func (check *Checker) inferB(tparams []*TypeParam, targs []Type) (types []Type, index int) {
+func (check *Checker) inferB(pos syntax.Pos, tparams []*TypeParam, targs []Type) (types []Type, index int) {
        assert(len(tparams) >= len(targs) && len(targs) > 0)
 
        // Setup bidirectional unification between constraints
@@ -388,7 +388,7 @@ func (check *Checker) inferB(tparams []*TypeParam, targs []Type) (types []Type,
                        if !u.unify(tpar, sbound) {
                                // TODO(gri) improve error message by providing the type arguments
                                //           which we know already
-                               check.errorf(tpar.obj, "%s does not match %s", tpar, sbound)
+                               check.errorf(pos, "%s does not match %s", tpar, sbound)
                                return nil, 0
                        }
                }

diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
index 9963d2ee003c165774539cca29614f05147908e9..cea8c1498321c7182c490d262cd9b4f58a03190f 100644 (file)
--- a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
+++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue45985.go2
@@ -4,11 +4,10 @@
 
 package issue45985
 
-// TODO(gri): this error should be on app[int] below.
-func app[S /* ERROR "S does not match" */ interface{ ~[]T }, T any](s S, e T) S {
+func app[S interface{ ~[]T }, T any](s S, e T) S {
     return append(s, e)
 }
 
 func _() {
-       _ = app[int]
+       _ = app[/* ERROR "S does not match" */int]
 }

diff --git a/src/go/types/infer.go b/src/go/types/infer.go
index 909042219c2912d5a0d97e5f96c677b0f35a3a45..a5088f27050bf35fffbd2afbc534697d9ffc7885 100644 (file)
--- a/src/go/types/infer.go
+++ b/src/go/types/infer.go
@@ -59,7 +59,7 @@ func (check *Checker) infer(posn positioner, tparams []*TypeParam, targs []Type,
        // If we have type arguments, see how far we get with constraint type inference.
        if len(targs) > 0 {
                var index int
-               targs, index = check.inferB(tparams, targs)
+               targs, index = check.inferB(posn, tparams, targs)
                if targs == nil || index < 0 {
                        return targs
                }
@@ -174,7 +174,7 @@ func (check *Checker) infer(posn positioner, tparams []*TypeParam, targs []Type,
        // See how far we get with constraint type inference.
        // Note that even if we don't have any type arguments, constraint type inference
        // may produce results for constraints that explicitly specify a type.
-       targs, index = check.inferB(tparams, targs)
+       targs, index = check.inferB(posn, tparams, targs)
        if targs == nil || index < 0 {
                return targs
        }
@@ -210,7 +210,7 @@ func (check *Checker) infer(posn positioner, tparams []*TypeParam, targs []Type,
        }
 
        // Again, follow up with constraint type inference.
-       targs, index = check.inferB(tparams, targs)
+       targs, index = check.inferB(posn, tparams, targs)
        if targs == nil || index < 0 {
                return targs
        }
@@ -359,7 +359,7 @@ func (w *tpWalker) isParameterizedTypeList(list []Type) bool {
 // first type argument in that list that couldn't be inferred (and thus is nil). If all
 // type arguments were inferred successfully, index is < 0. The number of type arguments
 // provided may be less than the number of type parameters, but there must be at least one.
-func (check *Checker) inferB(tparams []*TypeParam, targs []Type) (types []Type, index int) {
+func (check *Checker) inferB(posn positioner, tparams []*TypeParam, targs []Type) (types []Type, index int) {
        assert(len(tparams) >= len(targs) && len(targs) > 0)
 
        // Setup bidirectional unification between constraints
@@ -387,7 +387,7 @@ func (check *Checker) inferB(tparams []*TypeParam, targs []Type) (types []Type,
                        if !u.unify(tpar, sbound) {
                                // TODO(gri) improve error message by providing the type arguments
                                //           which we know already
-                               check.errorf(tpar.obj, _InvalidTypeArg, "%s does not match %s", tpar, sbound)
+                               check.errorf(posn, _InvalidTypeArg, "%s does not match %s", tpar, sbound)
                                return nil, 0
                        }
                }

diff --git a/src/go/types/testdata/fixedbugs/issue45985.go2 b/src/go/types/testdata/fixedbugs/issue45985.go2
index 637e2cad5e05e0f42513b790c7f150329c934191..9a0f5e36970058c347a5f312609f6821c208be59 100644 (file)
--- a/src/go/types/testdata/fixedbugs/issue45985.go2
+++ b/src/go/types/testdata/fixedbugs/issue45985.go2
@@ -4,11 +4,10 @@
 
 package issue45985
 
-// TODO(rFindley): this error should be on app[int] below.
-func app[S /* ERROR "S does not match" */ interface{ ~[]T }, T any](s S, e T) S {
+func app[S interface{ ~[]T }, T any](s S, e T) S {
     return append(s, e)
 }
 
 func _() {
-       _ = app[int]
+       _ = app/* ERROR "S does not match" */[int]
 }