package types
import (
+ "bytes"
"fmt"
"go/ast"
"go/token"
- "path"
+ . "internal/types/errors"
+ "runtime"
+ "strconv"
"strings"
)
func assert(p bool) {
if !p {
- panic("assertion failed")
+ 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)
}
}
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 {
+ posn positioner
+ format string
+ args []interface{}
+}
+
+func (err *error_) empty() bool {
+ return err.desc == nil
+}
+
+func (err *error_) pos() token.Pos {
+ if err.empty() {
+ return nopos
+ }
+ return err.desc[0].posn.Pos()
+}
+
+func (err *error_) msg(fset *token.FileSet, 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.posn.Pos().IsValid() {
+ fmt.Fprintf(&buf, "%s: ", fset.Position(p.posn.Pos()))
+ }
+ }
+ buf.WriteString(sprintf(fset, 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("%d: %s", err.pos(), err.msg(nil, nil))
+}
+
+// errorf adds formatted error information to err.
+// It may be called multiple times to provide additional information.
+func (err *error_) errorf(at token.Pos, format string, args ...interface{}) {
+ err.desc = append(err.desc, errorDesc{atPos(at), format, args})
+}
+
func (check *Checker) qualifier(pkg *Package) string {
+ // Qualify the package unless it's the package being type-checked.
if pkg != check.pkg {
- return path.Base(pkg.path) // avoid excessively long path names in error messages
+ 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 ""
}
-func (check *Checker) sprintf(format string, args ...interface{}) string {
+// 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 ...any) string {
+ var fset *token.FileSet
+ var qf Qualifier
+ if check != nil {
+ fset = check.fset
+ qf = check.qualifier
+ }
+ return sprintf(fset, qf, false, format, args...)
+}
+
+func sprintf(fset *token.FileSet, qf Qualifier, tpSubscripts bool, format string, args ...any) string {
for i, arg := range args {
switch a := arg.(type) {
case nil:
arg = "<nil>"
case operand:
- panic("internal error: should always pass *operand")
+ panic("got operand instead of *operand")
case *operand:
- arg = operandString(a, check.qualifier)
+ arg = operandString(a, qf)
case token.Pos:
- arg = check.fset.Position(a).String()
+ if fset != nil {
+ arg = fset.Position(a).String()
+ }
case ast.Expr:
arg = ExprString(a)
+ case []ast.Expr:
+ var buf bytes.Buffer
+ buf.WriteByte('[')
+ writeExprList(&buf, a)
+ buf.WriteByte(']')
+ arg = buf.String()
case Object:
- arg = ObjectString(a, check.qualifier)
+ arg = ObjectString(a, qf)
case Type:
- arg = TypeString(a, check.qualifier)
+ 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) trace(pos token.Pos, format string, args ...interface{}) {
+func (check *Checker) trace(pos token.Pos, format string, args ...any) {
fmt.Printf("%s:\t%s%s\n",
check.fset.Position(pos),
strings.Repeat(". ", check.indent),
- check.sprintf(format, args...),
+ sprintf(check.fset, check.qualifier, true, 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) dump(format string, args ...any) {
+ fmt.Println(sprintf(check.fset, check.qualifier, true, format, args...))
}
-func (check *Checker) err(pos token.Pos, msg string, soft bool) {
+// Report records the error pointed to by errp, setting check.firstError if
+// necessary.
+func (check *Checker) report(errp *error_) {
+ if errp.empty() {
+ panic("empty error details")
+ }
+
+ msg := errp.msg(check.fset, check.qualifier)
+ switch errp.code {
+ case InvalidSyntaxTree:
+ msg = "invalid AST: " + msg
+ case 0:
+ panic("no error code provided")
+ }
+
+ // If we have a URL for error codes, add a link to the first line.
+ if errp.code != 0 && check.conf._ErrorURL != "" {
+ u := fmt.Sprintf(check.conf._ErrorURL, errp.code)
+ if i := strings.Index(msg, "\n"); i >= 0 {
+ msg = msg[:i] + u + msg[i:]
+ } else {
+ msg += u
+ }
+ }
+
+ span := spanOf(errp.desc[0].posn)
+ e := Error{
+ Fset: check.fset,
+ Pos: span.pos,
+ Msg: msg,
+ Soft: errp.soft,
+ go116code: errp.code,
+ go116start: span.start,
+ go116end: span.end,
+ }
+
// 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) {
+ isInvalidErr := strings.Index(e.Msg, "invalid operand") > 0 || strings.Index(e.Msg, "invalid type") > 0
+ if check.firstErr != nil && isInvalidErr {
return
}
- err := Error{check.fset, pos, msg, soft}
+ 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 {
+ if check.conf._Trace {
+ pos := e.Pos
+ msg := e.Msg
check.trace(pos, "ERROR: %s", msg)
}
f(err)
}
-func (check *Checker) error(pos token.Pos, msg string) {
- check.err(pos, msg, false)
+const (
+ invalidArg = "invalid argument: "
+ invalidOp = "invalid operation: "
+)
+
+// newErrorf creates a new error_ for later reporting with check.report.
+func newErrorf(at positioner, code Code, format string, args ...any) *error_ {
+ return &error_{
+ desc: []errorDesc{{at, format, args}},
+ code: code,
+ }
+}
+
+func (check *Checker) error(at positioner, code Code, msg string) {
+ check.report(newErrorf(at, code, "%s", msg))
}
-func (check *Checker) errorf(pos token.Pos, format string, args ...interface{}) {
- check.err(pos, check.sprintf(format, args...), false)
+func (check *Checker) errorf(at positioner, code Code, format string, args ...any) {
+ check.report(newErrorf(at, code, format, args...))
}
-func (check *Checker) softErrorf(pos token.Pos, format string, args ...interface{}) {
- check.err(pos, check.sprintf(format, args...), true)
+func (check *Checker) softErrorf(at positioner, code Code, format string, args ...any) {
+ err := newErrorf(at, code, format, args...)
+ err.soft = true
+ check.report(err)
}
-func (check *Checker) invalidAST(pos token.Pos, format string, args ...interface{}) {
- check.errorf(pos, "invalid AST: "+format, args...)
+func (check *Checker) versionErrorf(at positioner, v goVersion, format string, args ...interface{}) {
+ msg := check.sprintf(format, args...)
+ var err *error_
+ err = newErrorf(at, UnsupportedFeature, "%s requires %s or later", msg, v)
+ check.report(err)
}
-func (check *Checker) invalidArg(pos token.Pos, format string, args ...interface{}) {
- check.errorf(pos, "invalid argument: "+format, args...)
+// The positioner interface is used to extract the position of type-checker
+// errors.
+type positioner interface {
+ Pos() token.Pos
}
-func (check *Checker) invalidOp(pos token.Pos, format string, args ...interface{}) {
- check.errorf(pos, "invalid operation: "+format, args...)
+// 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("nil positioner")
+ 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{nopos, nopos, nopos}
+ default:
+ pos := at.Pos()
+ return posSpan{pos, pos, 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
}