commit 71db9462eb994327a79928fbbaee3f3675458df1
author Michael Anthony Knyszek <mknyszek@google.com> Fri Dec 13 20:24:29 2024 +0000
committer Gopher Robot <gobot@golang.org> Mon Dec 16 13:41:15 2024 -0800
tree 5427bdba38d2605b94965fdd44ba5a9103e674f7
parent 5f2bbc1069aecbc97fce688b2feafecb0eedfe86

gocore: overhaul roots, expand testing

This change overhauls how roots work to prepare for supporting composite
values (roots "de-structured" and broken up into pieces, despite
representing a single type). It also expands testing a little bit to
prevent backsliding from this point.

Roots now do not have an address identity at all, and callers do not
rely on that fact anymore. They have a forged identity which is useful
for some calculations, but otherwise can only be identified by a *Root.

Pointers may now be found in composite roots, which is nice, so all
destructured values work correctly for the sake of iterating over all
pointers.

Finally, this fixes a small, old bug in typeObject where the type
pointer would be interrogated before we filtered out whether a interface
was nil or not. Because we filter dead pointers by making them appear
nil, this means we could end up looking at a bogus, clobbered type
pointer. (This may be a bug in the compiler's DWARF generation, the type
shouldn't be clobbered.)

Change-Id: I09217b2070dc6f4bf4b1dbd28d52f570ba61ca4a
Reviewed-on: https://go-review.googlesource.com/c/debug/+/635857
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Nicolas Hillegeer <aktau@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>