cmd/compile/internal/types2: simplify error reporting API (cleanup)

- Remove specialized errorf functions for invalid AST/argument/operation.
  Instead use prefix constants with the error message.

- Replace several calls to Checker.errorf with calls to Checker.error
  if there are no arguments to format.

- Replace a handful of %s format verbs with %v to satisfy vet check.

- Add a basic test that checks that we're not using Checker.errorf when
  we should be using Checker.error.

Change-Id: I7bc7c14f3cf774689ec8cd5782ea31b6e30dbcd6
Reviewed-on: https://go-review.googlesource.com/c/go/+/300995
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

1 files changed, 12 insertions, 16 deletions

diff --git a/src/cmd/compile/internal/types2/errors.go b/src/cmd/compile/internal/types2/errors.go
index 01df50c8e3..79fedc91e1 100644
--- a/src/cmd/compile/internal/types2/errors.go
+++ b/src/cmd/compile/internal/types2/errors.go
@@ -142,7 +142,7 @@ func (check *Checker) dump(format string, args ...interface{}) {
 	fmt.Println(check.sprintf(format, args...))
 }
 
-func (check *Checker) err(pos syntax.Pos, msg string, soft bool) {
+func (check *Checker) err(at poser, msg string, soft bool) {
 	// Cheap trick: Don't report errors with messages containing
 	// "invalid operand" or "invalid type" as those tend to be
 	// follow-on errors which don't add useful information. Only
@@ -152,6 +152,8 @@ func (check *Checker) err(pos syntax.Pos, msg string, soft bool) {
 		return
 	}
 
+	pos := posFor(at)
+
 	// If we are encountering an error while evaluating an inherited
 	// constant initialization expression, pos is the position of in
 	// the original expression, and not of the currently declared
@@ -179,32 +181,26 @@ func (check *Checker) err(pos syntax.Pos, msg string, soft bool) {
 	f(err)
 }
 
+const (
+	invalidAST = "invalid AST: "
+	invalidArg = "invalid argument: "
+	invalidOp  = "invalid operation: "
+)
+
 type poser interface {
 	Pos() syntax.Pos
 }
 
 func (check *Checker) error(at poser, msg string) {
-	check.err(posFor(at), msg, false)
+	check.err(at, msg, false)
 }
 
 func (check *Checker) errorf(at poser, format string, args ...interface{}) {
-	check.err(posFor(at), check.sprintf(format, args...), false)
+	check.err(at, check.sprintf(format, args...), false)
 }
 
 func (check *Checker) softErrorf(at poser, format string, args ...interface{}) {
-	check.err(posFor(at), check.sprintf(format, args...), true)
-}
-
-func (check *Checker) invalidASTf(at poser, format string, args ...interface{}) {
-	check.errorf(at, "invalid AST: "+format, args...)
-}
-
-func (check *Checker) invalidArgf(at poser, format string, args ...interface{}) {
-	check.errorf(at, "invalid argument: "+format, args...)
-}
-
-func (check *Checker) invalidOpf(at poser, format string, args ...interface{}) {
-	check.errorf(at, "invalid operation: "+format, args...)
+	check.err(at, check.sprintf(format, args...), true)
 }
 
 // posFor reports the left (= start) position of at.