blob: 226310641733ae833e91e63064ec6a8db71ea469 [file] [log] [blame]
// Copyright 2012 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.
// This file implements various error reporters.
package types
import (
"errors"
"fmt"
"go/ast"
"go/token"
"strconv"
"strings"
)
func assert(p bool) {
if !p {
panic("assertion failed")
}
}
func unreachable() {
panic("unreachable")
}
func (check *Checker) qualifier(pkg *Package) string {
// Qualify the package unless it's the package being type-checked.
if pkg != check.pkg {
if check.pkgPathMap == nil {
check.pkgPathMap = make(map[string]map[string]bool)
check.seenPkgMap = make(map[*Package]bool)
check.markImports(check.pkg)
}
// If the same package name was used by multiple packages, display the full path.
if len(check.pkgPathMap[pkg.name]) > 1 {
return strconv.Quote(pkg.path)
}
return pkg.name
}
return ""
}
// markImports recursively walks pkg and its imports, to record unique import
// paths in pkgPathMap.
func (check *Checker) markImports(pkg *Package) {
if check.seenPkgMap[pkg] {
return
}
check.seenPkgMap[pkg] = true
forName, ok := check.pkgPathMap[pkg.name]
if !ok {
forName = make(map[string]bool)
check.pkgPathMap[pkg.name] = forName
}
forName[pkg.path] = true
for _, imp := range pkg.imports {
check.markImports(imp)
}
}
func (check *Checker) sprintf(format string, args ...interface{}) string {
for i, arg := range args {
switch a := arg.(type) {
case nil:
arg = "<nil>"
case operand:
panic("internal error: should always pass *operand")
case *operand:
arg = operandString(a, check.qualifier)
case token.Pos:
arg = check.fset.Position(a).String()
case ast.Expr:
arg = ExprString(a)
case Object:
arg = ObjectString(a, check.qualifier)
case Type:
arg = TypeString(a, check.qualifier)
}
args[i] = arg
}
return fmt.Sprintf(format, args...)
}
func (check *Checker) trace(pos token.Pos, format string, args ...interface{}) {
fmt.Printf("%s:\t%s%s\n",
check.fset.Position(pos),
strings.Repeat(". ", check.indent),
check.sprintf(format, args...),
)
}
// dump is only needed for debugging
func (check *Checker) dump(format string, args ...interface{}) {
fmt.Println(check.sprintf(format, args...))
}
func (check *Checker) err(err error) {
if err == nil {
return
}
var e Error
isInternal := errors.As(err, &e)
// 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
// exclude them if these strings are not at the beginning,
// and only if we have at least one error already reported.
isInvalidErr := isInternal && (strings.Index(e.Msg, "invalid operand") > 0 || strings.Index(e.Msg, "invalid type") > 0)
if check.firstErr != nil && isInvalidErr {
return
}
if isInternal {
e.Msg = stripAnnotations(e.Msg)
if check.errpos != nil {
// If we have an internal error and the errpos override is set, use it to
// augment our error positioning.
// TODO(rFindley) we may also want to augment the error message and refer
// to the position (pos) in the original expression.
span := spanOf(check.errpos)
e.Pos = span.pos
e.go116start = span.start
e.go116end = span.end
}
err = e
}
if check.firstErr == nil {
check.firstErr = err
}
if trace {
pos := e.Pos
msg := e.Msg
if !isInternal {
msg = err.Error()
pos = token.NoPos
}
check.trace(pos, "ERROR: %s", msg)
}
f := check.conf.Error
if f == nil {
panic(bailout{}) // report only first error
}
f(err)
}
func (check *Checker) newError(at positioner, code errorCode, soft bool, msg string) error {
span := spanOf(at)
return Error{
Fset: check.fset,
Pos: span.pos,
Msg: msg,
Soft: soft,
go116code: code,
go116start: span.start,
go116end: span.end,
}
}
// newErrorf creates a new Error, but does not handle it.
func (check *Checker) newErrorf(at positioner, code errorCode, soft bool, format string, args ...interface{}) error {
msg := check.sprintf(format, args...)
return check.newError(at, code, soft, msg)
}
func (check *Checker) error(at positioner, code errorCode, msg string) {
check.err(check.newError(at, code, false, msg))
}
func (check *Checker) errorf(at positioner, code errorCode, format string, args ...interface{}) {
check.error(at, code, check.sprintf(format, args...))
}
func (check *Checker) softErrorf(at positioner, code errorCode, format string, args ...interface{}) {
check.err(check.newErrorf(at, code, true, format, args...))
}
func (check *Checker) invalidAST(at positioner, format string, args ...interface{}) {
check.errorf(at, 0, "invalid AST: "+format, args...)
}
func (check *Checker) invalidArg(at positioner, code errorCode, format string, args ...interface{}) {
check.errorf(at, code, "invalid argument: "+format, args...)
}
func (check *Checker) invalidOp(at positioner, code errorCode, format string, args ...interface{}) {
check.errorf(at, code, "invalid operation: "+format, args...)
}
// The positioner interface is used to extract the position of type-checker
// errors.
type positioner interface {
Pos() token.Pos
}
// posSpan holds a position range along with a highlighted position within that
// range. This is used for positioning errors, with pos by convention being the
// first position in the source where the error is known to exist, and start
// and end defining the full span of syntax being considered when the error was
// detected. Invariant: start <= pos < end || start == pos == end.
type posSpan struct {
start, pos, end token.Pos
}
func (e posSpan) Pos() token.Pos {
return e.pos
}
// inNode creates a posSpan for the given node.
// Invariant: node.Pos() <= pos < node.End() (node.End() is the position of the
// first byte after node within the source).
func inNode(node ast.Node, pos token.Pos) posSpan {
start, end := node.Pos(), node.End()
if debug {
assert(start <= pos && pos < end)
}
return posSpan{start, pos, end}
}
// atPos wraps a token.Pos to implement the positioner interface.
type atPos token.Pos
func (s atPos) Pos() token.Pos {
return token.Pos(s)
}
// spanOf extracts an error span from the given positioner. By default this is
// the trivial span starting and ending at pos, but this span is expanded when
// the argument naturally corresponds to a span of source code.
func spanOf(at positioner) posSpan {
switch x := at.(type) {
case nil:
panic("internal error: nil")
case posSpan:
return x
case ast.Node:
pos := x.Pos()
return posSpan{pos, pos, x.End()}
case *operand:
if x.expr != nil {
pos := x.Pos()
return posSpan{pos, pos, x.expr.End()}
}
return posSpan{token.NoPos, token.NoPos, token.NoPos}
default:
pos := at.Pos()
return posSpan{pos, pos, pos}
}
}
// stripAnnotations removes internal (type) annotations from s.
func stripAnnotations(s string) string {
var b strings.Builder
for _, r := range s {
// strip #'s and subscript digits
if r != instanceMarker && !('₀' <= r && r < '₀'+10) { // '₀' == U+2080
b.WriteRune(r)
}
}
if b.Len() < len(s) {
return b.String()
}
return s
}