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// 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 types2
import (
"bytes"
"cmd/compile/internal/syntax"
"fmt"
. "internal/types/errors"
"runtime"
"strconv"
"strings"
)
func assert(p bool) {
if !p {
msg := "assertion failed"
// Include information about the assertion location. Due to panic recovery,
// this location is otherwise buried in the middle of the panicking stack.
if _, file, line, ok := runtime.Caller(1); ok {
msg = fmt.Sprintf("%s:%d: %s", file, line, msg)
}
panic(msg)
}
}
func unreachable() {
panic("unreachable")
}
// An error_ represents a type-checking error.
// To report an error_, call Checker.report.
type error_ struct {
desc []errorDesc
code Code
soft bool // TODO(gri) eventually determine this from an error code
}
// An errorDesc describes part of a type-checking error.
type errorDesc struct {
pos syntax.Pos
format string
args []interface{}
}
func (err *error_) empty() bool {
return err.desc == nil
}
func (err *error_) pos() syntax.Pos {
if err.empty() {
return nopos
}
return err.desc[0].pos
}
func (err *error_) msg(qf Qualifier) string {
if err.empty() {
return "no error"
}
var buf strings.Builder
for i := range err.desc {
p := &err.desc[i]
if i > 0 {
fmt.Fprint(&buf, "\n\t")
if p.pos.IsKnown() {
fmt.Fprintf(&buf, "%s: ", p.pos)
}
}
buf.WriteString(sprintf(qf, false, p.format, p.args...))
}
return buf.String()
}
// String is for testing.
func (err *error_) String() string {
if err.empty() {
return "no error"
}
return fmt.Sprintf("%s: %s", err.pos(), err.msg(nil))
}
// errorf adds formatted error information to err.
// It may be called multiple times to provide additional information.
func (err *error_) errorf(at poser, format string, args ...interface{}) {
err.desc = append(err.desc, errorDesc{atPos(at), format, args})
}
func sprintf(qf Qualifier, tpSubscripts bool, format string, args ...interface{}) string {
for i, arg := range args {
switch a := arg.(type) {
case nil:
arg = "<nil>"
case operand:
panic("got operand instead of *operand")
case *operand:
arg = operandString(a, qf)
case syntax.Pos:
arg = a.String()
case syntax.Expr:
arg = syntax.String(a)
case []syntax.Expr:
var buf strings.Builder
buf.WriteByte('[')
for i, x := range a {
if i > 0 {
buf.WriteString(", ")
}
buf.WriteString(syntax.String(x))
}
buf.WriteByte(']')
arg = buf.String()
case Object:
arg = ObjectString(a, qf)
case Type:
var buf bytes.Buffer
w := newTypeWriter(&buf, qf)
w.tpSubscripts = tpSubscripts
w.typ(a)
arg = buf.String()
case []Type:
var buf bytes.Buffer
w := newTypeWriter(&buf, qf)
w.tpSubscripts = tpSubscripts
buf.WriteByte('[')
for i, x := range a {
if i > 0 {
buf.WriteString(", ")
}
w.typ(x)
}
buf.WriteByte(']')
arg = buf.String()
case []*TypeParam:
var buf bytes.Buffer
w := newTypeWriter(&buf, qf)
w.tpSubscripts = tpSubscripts
buf.WriteByte('[')
for i, x := range a {
if i > 0 {
buf.WriteString(", ")
}
w.typ(x)
}
buf.WriteByte(']')
arg = buf.String()
}
args[i] = arg
}
return fmt.Sprintf(format, args...)
}
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)
}
}
// check may be nil.
func (check *Checker) sprintf(format string, args ...interface{}) string {
var qf Qualifier
if check != nil {
qf = check.qualifier
}
return sprintf(qf, false, format, args...)
}
func (check *Checker) report(err *error_) {
if err.empty() {
panic("no error to report")
}
check.err(err.pos(), err.code, err.msg(check.qualifier), err.soft)
}
func (check *Checker) trace(pos syntax.Pos, format string, args ...interface{}) {
fmt.Printf("%s:\t%s%s\n",
pos,
strings.Repeat(". ", check.indent),
sprintf(check.qualifier, true, format, args...),
)
}
// dump is only needed for debugging
func (check *Checker) dump(format string, args ...interface{}) {
fmt.Println(sprintf(check.qualifier, true, format, args...))
}
func (check *Checker) err(at poser, code Code, msg string, soft bool) {
switch code {
case InvalidSyntaxTree:
msg = "invalid syntax tree: " + msg
case 0:
panic("no error code provided")
}
// 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.
if check.firstErr != nil && (strings.Index(msg, "invalid operand") > 0 || strings.Index(msg, "invalid type") > 0) {
return
}
pos := atPos(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
// constant identifier. Use the provided errpos instead.
// TODO(gri) We may also want to augment the error message and
// refer to the position (pos) in the original expression.
if check.errpos.IsKnown() {
assert(check.iota != nil)
pos = check.errpos
}
// If we have an URL for error codes, add a link to the first line.
if code != 0 && check.conf.ErrorURL != "" {
u := fmt.Sprintf(check.conf.ErrorURL, code)
if i := strings.Index(msg, "\n"); i >= 0 {
msg = msg[:i] + u + msg[i:]
} else {
msg += u
}
}
err := Error{pos, stripAnnotations(msg), msg, soft, code}
if check.firstErr == nil {
check.firstErr = err
}
if check.conf.Trace {
check.trace(pos, "ERROR: %s", msg)
}
f := check.conf.Error
if f == nil {
panic(bailout{}) // report only first error
}
f(err)
}
const (
invalidArg = "invalid argument: "
invalidOp = "invalid operation: "
)
type poser interface {
Pos() syntax.Pos
}
func (check *Checker) error(at poser, code Code, msg string) {
check.err(at, code, msg, false)
}
func (check *Checker) errorf(at poser, code Code, format string, args ...interface{}) {
check.err(at, code, check.sprintf(format, args...), false)
}
func (check *Checker) softErrorf(at poser, code Code, format string, args ...interface{}) {
check.err(at, code, check.sprintf(format, args...), true)
}
func (check *Checker) versionErrorf(at poser, v version, format string, args ...interface{}) {
msg := check.sprintf(format, args...)
msg = fmt.Sprintf("%s requires %s or later", msg, v)
check.err(at, UnsupportedFeature, msg, true)
}
// atPos reports the left (= start) position of at.
func atPos(at poser) syntax.Pos {
switch x := at.(type) {
case *operand:
if x.expr != nil {
return syntax.StartPos(x.expr)
}
case syntax.Node:
return syntax.StartPos(x)
}
return at.Pos()
}
// stripAnnotations removes internal (type) annotations from s.
func stripAnnotations(s string) string {
var buf strings.Builder
for _, r := range s {
// strip #'s and subscript digits
if r < '₀' || '₀'+10 <= r { // '₀' == U+2080
buf.WriteRune(r)
}
}
if buf.Len() < len(s) {
return buf.String()
}
return s
}