| // Copyright 2020 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. |
| |
| package base |
| |
| import ( |
| "fmt" |
| "internal/buildcfg" |
| "internal/types/errors" |
| "os" |
| "runtime/debug" |
| "sort" |
| "strings" |
| |
| "cmd/internal/src" |
| "cmd/internal/telemetry" |
| ) |
| |
| // An errorMsg is a queued error message, waiting to be printed. |
| type errorMsg struct { |
| pos src.XPos |
| msg string |
| code errors.Code |
| } |
| |
| // Pos is the current source position being processed, |
| // printed by Errorf, ErrorfLang, Fatalf, and Warnf. |
| var Pos src.XPos |
| |
| var ( |
| errorMsgs []errorMsg |
| numErrors int // number of entries in errorMsgs that are errors (as opposed to warnings) |
| numSyntaxErrors int |
| ) |
| |
| // Errors returns the number of errors reported. |
| func Errors() int { |
| return numErrors |
| } |
| |
| // SyntaxErrors returns the number of syntax errors reported. |
| func SyntaxErrors() int { |
| return numSyntaxErrors |
| } |
| |
| // addErrorMsg adds a new errorMsg (which may be a warning) to errorMsgs. |
| func addErrorMsg(pos src.XPos, code errors.Code, format string, args ...interface{}) { |
| msg := fmt.Sprintf(format, args...) |
| // Only add the position if know the position. |
| // See issue golang.org/issue/11361. |
| if pos.IsKnown() { |
| msg = fmt.Sprintf("%v: %s", FmtPos(pos), msg) |
| } |
| errorMsgs = append(errorMsgs, errorMsg{ |
| pos: pos, |
| msg: msg + "\n", |
| code: code, |
| }) |
| } |
| |
| // FmtPos formats pos as a file:line string. |
| func FmtPos(pos src.XPos) string { |
| if Ctxt == nil { |
| return "???" |
| } |
| return Ctxt.OutermostPos(pos).Format(Flag.C == 0, Flag.L == 1) |
| } |
| |
| // byPos sorts errors by source position. |
| type byPos []errorMsg |
| |
| func (x byPos) Len() int { return len(x) } |
| func (x byPos) Less(i, j int) bool { return x[i].pos.Before(x[j].pos) } |
| func (x byPos) Swap(i, j int) { x[i], x[j] = x[j], x[i] } |
| |
| // FlushErrors sorts errors seen so far by line number, prints them to stdout, |
| // and empties the errors array. |
| func FlushErrors() { |
| if Ctxt != nil && Ctxt.Bso != nil { |
| Ctxt.Bso.Flush() |
| } |
| if len(errorMsgs) == 0 { |
| return |
| } |
| sort.Stable(byPos(errorMsgs)) |
| for i, err := range errorMsgs { |
| if i == 0 || err.msg != errorMsgs[i-1].msg { |
| fmt.Print(err.msg) |
| } |
| } |
| errorMsgs = errorMsgs[:0] |
| } |
| |
| // lasterror keeps track of the most recently issued error, |
| // to avoid printing multiple error messages on the same line. |
| var lasterror struct { |
| syntax src.XPos // source position of last syntax error |
| other src.XPos // source position of last non-syntax error |
| msg string // error message of last non-syntax error |
| } |
| |
| // sameline reports whether two positions a, b are on the same line. |
| func sameline(a, b src.XPos) bool { |
| p := Ctxt.PosTable.Pos(a) |
| q := Ctxt.PosTable.Pos(b) |
| return p.Base() == q.Base() && p.Line() == q.Line() |
| } |
| |
| // Errorf reports a formatted error at the current line. |
| func Errorf(format string, args ...interface{}) { |
| ErrorfAt(Pos, 0, format, args...) |
| } |
| |
| // ErrorfAt reports a formatted error message at pos. |
| func ErrorfAt(pos src.XPos, code errors.Code, format string, args ...interface{}) { |
| msg := fmt.Sprintf(format, args...) |
| |
| if strings.HasPrefix(msg, "syntax error") { |
| numSyntaxErrors++ |
| // only one syntax error per line, no matter what error |
| if sameline(lasterror.syntax, pos) { |
| return |
| } |
| lasterror.syntax = pos |
| } else { |
| // only one of multiple equal non-syntax errors per line |
| // (FlushErrors shows only one of them, so we filter them |
| // here as best as we can (they may not appear in order) |
| // so that we don't count them here and exit early, and |
| // then have nothing to show for.) |
| if sameline(lasterror.other, pos) && lasterror.msg == msg { |
| return |
| } |
| lasterror.other = pos |
| lasterror.msg = msg |
| } |
| |
| addErrorMsg(pos, code, "%s", msg) |
| numErrors++ |
| |
| hcrash() |
| if numErrors >= 10 && Flag.LowerE == 0 { |
| FlushErrors() |
| fmt.Printf("%v: too many errors\n", FmtPos(pos)) |
| ErrorExit() |
| } |
| } |
| |
| // UpdateErrorDot is a clumsy hack that rewrites the last error, |
| // if it was "LINE: undefined: NAME", to be "LINE: undefined: NAME in EXPR". |
| // It is used to give better error messages for dot (selector) expressions. |
| func UpdateErrorDot(line string, name, expr string) { |
| if len(errorMsgs) == 0 { |
| return |
| } |
| e := &errorMsgs[len(errorMsgs)-1] |
| if strings.HasPrefix(e.msg, line) && e.msg == fmt.Sprintf("%v: undefined: %v\n", line, name) { |
| e.msg = fmt.Sprintf("%v: undefined: %v in %v\n", line, name, expr) |
| } |
| } |
| |
| // Warn reports a formatted warning at the current line. |
| // In general the Go compiler does NOT generate warnings, |
| // so this should be used only when the user has opted in |
| // to additional output by setting a particular flag. |
| func Warn(format string, args ...interface{}) { |
| WarnfAt(Pos, format, args...) |
| } |
| |
| // WarnfAt reports a formatted warning at pos. |
| // In general the Go compiler does NOT generate warnings, |
| // so this should be used only when the user has opted in |
| // to additional output by setting a particular flag. |
| func WarnfAt(pos src.XPos, format string, args ...interface{}) { |
| addErrorMsg(pos, 0, format, args...) |
| if Flag.LowerM != 0 { |
| FlushErrors() |
| } |
| } |
| |
| // Fatalf reports a fatal error - an internal problem - at the current line and exits. |
| // If other errors have already been printed, then Fatalf just quietly exits. |
| // (The internal problem may have been caused by incomplete information |
| // after the already-reported errors, so best to let users fix those and |
| // try again without being bothered about a spurious internal error.) |
| // |
| // But if no errors have been printed, or if -d panic has been specified, |
| // Fatalf prints the error as an "internal compiler error". In a released build, |
| // it prints an error asking to file a bug report. In development builds, it |
| // prints a stack trace. |
| // |
| // If -h has been specified, Fatalf panics to force the usual runtime info dump. |
| func Fatalf(format string, args ...interface{}) { |
| FatalfAt(Pos, format, args...) |
| } |
| |
| var bugStack = telemetry.NewStackCounter("compile/bug", 16) // 16 is arbitrary; used by gopls and crashmonitor |
| |
| // FatalfAt reports a fatal error - an internal problem - at pos and exits. |
| // If other errors have already been printed, then FatalfAt just quietly exits. |
| // (The internal problem may have been caused by incomplete information |
| // after the already-reported errors, so best to let users fix those and |
| // try again without being bothered about a spurious internal error.) |
| // |
| // But if no errors have been printed, or if -d panic has been specified, |
| // FatalfAt prints the error as an "internal compiler error". In a released build, |
| // it prints an error asking to file a bug report. In development builds, it |
| // prints a stack trace. |
| // |
| // If -h has been specified, FatalfAt panics to force the usual runtime info dump. |
| func FatalfAt(pos src.XPos, format string, args ...interface{}) { |
| FlushErrors() |
| |
| bugStack.Inc() |
| |
| if Debug.Panic != 0 || numErrors == 0 { |
| fmt.Printf("%v: internal compiler error: ", FmtPos(pos)) |
| fmt.Printf(format, args...) |
| fmt.Printf("\n") |
| |
| // If this is a released compiler version, ask for a bug report. |
| if Debug.Panic == 0 && strings.HasPrefix(buildcfg.Version, "go") { |
| fmt.Printf("\n") |
| fmt.Printf("Please file a bug report including a short program that triggers the error.\n") |
| fmt.Printf("https://go.dev/issue/new\n") |
| } else { |
| // Not a release; dump a stack trace, too. |
| fmt.Println() |
| os.Stdout.Write(debug.Stack()) |
| fmt.Println() |
| } |
| } |
| |
| hcrash() |
| ErrorExit() |
| } |
| |
| // Assert reports "assertion failed" with Fatalf, unless b is true. |
| func Assert(b bool) { |
| if !b { |
| Fatalf("assertion failed") |
| } |
| } |
| |
| // Assertf reports a fatal error with Fatalf, unless b is true. |
| func Assertf(b bool, format string, args ...interface{}) { |
| if !b { |
| Fatalf(format, args...) |
| } |
| } |
| |
| // AssertfAt reports a fatal error with FatalfAt, unless b is true. |
| func AssertfAt(b bool, pos src.XPos, format string, args ...interface{}) { |
| if !b { |
| FatalfAt(pos, format, args...) |
| } |
| } |
| |
| // hcrash crashes the compiler when -h is set, to find out where a message is generated. |
| func hcrash() { |
| if Flag.LowerH != 0 { |
| FlushErrors() |
| if Flag.LowerO != "" { |
| os.Remove(Flag.LowerO) |
| } |
| panic("-h") |
| } |
| } |
| |
| // ErrorExit handles an error-status exit. |
| // It flushes any pending errors, removes the output file, and exits. |
| func ErrorExit() { |
| FlushErrors() |
| if Flag.LowerO != "" { |
| os.Remove(Flag.LowerO) |
| } |
| os.Exit(2) |
| } |
| |
| // ExitIfErrors calls ErrorExit if any errors have been reported. |
| func ExitIfErrors() { |
| if Errors() > 0 { |
| ErrorExit() |
| } |
| } |
| |
| var AutogeneratedPos src.XPos |