fmt: include failing method name in panic message
Fixes #25707
Change-Id: Idfa379db8cc0e105ea68455ec0b4a0dbc1b3f485
Reviewed-on: https://go-review.googlesource.com/c/153827
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/fmt/fmt_test.go b/src/fmt/fmt_test.go
index 1907268..068c262 100644
--- a/src/fmt/fmt_test.go
+++ b/src/fmt/fmt_test.go
@@ -1683,18 +1683,18 @@
}{
// String
{"%s", (*PanicS)(nil), "<nil>"}, // nil pointer special case
- {"%s", PanicS{io.ErrUnexpectedEOF}, "%!s(PANIC=unexpected EOF)"},
- {"%s", PanicS{3}, "%!s(PANIC=3)"},
+ {"%s", PanicS{io.ErrUnexpectedEOF}, "%!s(PANIC=String method: unexpected EOF)"},
+ {"%s", PanicS{3}, "%!s(PANIC=String method: 3)"},
// GoString
{"%#v", (*PanicGo)(nil), "<nil>"}, // nil pointer special case
- {"%#v", PanicGo{io.ErrUnexpectedEOF}, "%!v(PANIC=unexpected EOF)"},
- {"%#v", PanicGo{3}, "%!v(PANIC=3)"},
+ {"%#v", PanicGo{io.ErrUnexpectedEOF}, "%!v(PANIC=GoString method: unexpected EOF)"},
+ {"%#v", PanicGo{3}, "%!v(PANIC=GoString method: 3)"},
// Issue 18282. catchPanic should not clear fmtFlags permanently.
- {"%#v", []interface{}{PanicGo{3}, PanicGo{3}}, "[]interface {}{%!v(PANIC=3), %!v(PANIC=3)}"},
+ {"%#v", []interface{}{PanicGo{3}, PanicGo{3}}, "[]interface {}{%!v(PANIC=GoString method: 3), %!v(PANIC=GoString method: 3)}"},
// Format
{"%s", (*PanicF)(nil), "<nil>"}, // nil pointer special case
- {"%s", PanicF{io.ErrUnexpectedEOF}, "%!s(PANIC=unexpected EOF)"},
- {"%s", PanicF{3}, "%!s(PANIC=3)"},
+ {"%s", PanicF{io.ErrUnexpectedEOF}, "%!s(PANIC=Format method: unexpected EOF)"},
+ {"%s", PanicF{3}, "%!s(PANIC=Format method: 3)"},
}
func TestPanics(t *testing.T) {
diff --git a/src/fmt/print.go b/src/fmt/print.go
index 5df34a2..42fcd8b 100644
--- a/src/fmt/print.go
+++ b/src/fmt/print.go
@@ -538,7 +538,7 @@
}
}
-func (p *pp) catchPanic(arg interface{}, verb rune) {
+func (p *pp) catchPanic(arg interface{}, verb rune, method string) {
if err := recover(); err != nil {
// If it's a nil pointer, just say "<nil>". The likeliest causes are a
// Stringer that fails to guard against nil or a nil pointer for a
@@ -561,6 +561,8 @@
p.buf.WriteString(percentBangString)
p.buf.WriteRune(verb)
p.buf.WriteString(panicString)
+ p.buf.WriteString(method)
+ p.buf.WriteString(" method: ")
p.panicking = true
p.printArg(err, 'v')
p.panicking = false
@@ -577,7 +579,7 @@
// Is it a Formatter?
if formatter, ok := p.arg.(Formatter); ok {
handled = true
- defer p.catchPanic(p.arg, verb)
+ defer p.catchPanic(p.arg, verb, "Format")
formatter.Format(p, verb)
return
}
@@ -586,7 +588,7 @@
if p.fmt.sharpV {
if stringer, ok := p.arg.(GoStringer); ok {
handled = true
- defer p.catchPanic(p.arg, verb)
+ defer p.catchPanic(p.arg, verb, "GoString")
// Print the result of GoString unadorned.
p.fmt.fmtS(stringer.GoString())
return
@@ -604,13 +606,13 @@
switch v := p.arg.(type) {
case error:
handled = true
- defer p.catchPanic(p.arg, verb)
+ defer p.catchPanic(p.arg, verb, "Error")
p.fmtString(v.Error(), verb)
return
case Stringer:
handled = true
- defer p.catchPanic(p.arg, verb)
+ defer p.catchPanic(p.arg, verb, "String")
p.fmtString(v.String(), verb)
return
}