runtime: make gcDumpObject useful on stack frames
gcDumpObject is often used on a stack pointer (for example, when
checkmark finds an unmarked object on the stack), but since stack
spans don't have an elemsize, it doesn't print any of the memory from
the frame. Make it at least slightly more useful by printing
everything between obj and obj+off (inclusive). While we're here, also
print out the span state.
Change-Id: I51be064ea8791b4a365865bfdc7afa7b5aaecfbd
Reviewed-on: https://go-review.googlesource.com/30142
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go
index 003073f..aa107ee 100644
--- a/src/runtime/mgcmark.go
+++ b/src/runtime/mgcmark.go
@@ -1320,9 +1320,22 @@
print(" s=nil\n")
return
}
- print(" s.base()=", hex(s.base()), " s.limit=", hex(s.limit), " s.sizeclass=", s.sizeclass, " s.elemsize=", s.elemsize, "\n")
+ print(" s.base()=", hex(s.base()), " s.limit=", hex(s.limit), " s.sizeclass=", s.sizeclass, " s.elemsize=", s.elemsize, " s.state=")
+ if 0 <= s.state && int(s.state) < len(mSpanStateNames) {
+ print(mSpanStateNames[s.state], "\n")
+ } else {
+ print("unknown(", s.state, ")\n")
+ }
+
skipped := false
- for i := uintptr(0); i < s.elemsize; i += sys.PtrSize {
+ size := s.elemsize
+ if s.state == _MSpanStack && size == 0 {
+ // We're printing something from a stack frame. We
+ // don't know how big it is, so just show up to an
+ // including off.
+ size = off + sys.PtrSize
+ }
+ for i := uintptr(0); i < size; i += sys.PtrSize {
// For big objects, just print the beginning (because
// that usually hints at the object's type) and the
// fields around off.
