Commit Graph

14 Commits

Author SHA1 Message Date
Dominik Honnef a434f64ace go/pointer: support reflect.Value in AddExtendedQuery
We were calling types.Type.Underlying() too early, which caused CanPoint
to see an ordinary struct, not reflect.Value.

Change-Id: I23ba3b9451bc1abc1ad8a45c790d2e22c1481f26
Reviewed-on: https://go-review.googlesource.com/129196
Run-TryBot: Dominik Honnef <dominik@honnef.co>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
2018-08-13 20:51:10 +00:00
Dominik Honnef a99f4ece36 go/pointer: implement extended queries
The existing API for querying values only allows directly querying
pointer-like values, or pointers to such values. The new, extended
queries make it possible to destructure values and access arbitrarily
nested pointers, such as fields in structs, or specific values in
tuples.

We use single Go expressions as the queries, which we further restrict
to a subset of the language (indexing, field access, pointer
dereferences and channel receives).

Instead of adding another map to Result, we return a *Pointer and
populate it during analysis. This does mean that a Config cannot be
reused for multiple analyses, as it now holds analysis-specific state.
That is, however, not a big problem as reusing one Config had little
use.

Since the new API can do everything the old could, it deprecates
AddQuery and AddIndirectQuery.

Change-Id: I4b2ae7d85c462bc7faa6bab76456106e76be5a65
Reviewed-on: https://go-review.googlesource.com/37635
Reviewed-by: Alan Donovan <adonovan@google.com>
2017-03-06 04:11:41 +00:00
Alan Donovan b56ef30191 tools: updates for minimum Go version 1.6
Details:
- remove go1.5 "default version" labels on most files
- remove go1.6 labels on a few files
- go/loader: use conf.Cwd not "." in a couple places; update faulty
  test expectations.  (Not sure why this wasn't caught sooner.)
- go/ssa/interp: add 'mono' result to time.now intrinsic
- go/gcimporter15/bimport.go: make consistent with the version in gc
- go/ssa/interp: update test error message
- go/ssa: update a comment

The go/gcimporter15/bexport.go logic is stale and needs to be brought
up to date.  Needs a separate CL since it's tricky.

Tested on go1.6, go1.7, go1.8.

Change-Id: I841189d30e131b7c49a4e8690ea7c40b55041bae
Reviewed-on: https://go-review.googlesource.com/36540
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-02-07 21:06:19 +00:00
Alan Donovan 2477c0d578 x/tools/...: fork and tag !1.5 all files that use go/types et al
This change will ensure that the tree continues to work with go1.4.1.

All files continue to depend on golang.org/x/tools/go/types, but in a
follow-up change, I will switch the primary files to depend on the
standard go/types package.  Another (smaller) set of files will be
forked and tagged, this time !1.6, due to API differences between the
two packages.

All tests pass using 1.4.1, 1.5, and ~1.6 (tip).

Change-Id: Ifd75a6330e120957d646be91693daaba1ce0e8c9
Reviewed-on: https://go-review.googlesource.com/18333
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-01-06 20:40:09 +00:00
Alan Donovan d4e7010150 go/pointer: add TODO comment
Change-Id: Ic383036a6b3aa092aa571694bba86d821428f236
Reviewed-on: https://go-review.googlesource.com/8385
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-04-02 18:06:43 +00:00
Andrew Gerrand 5ebbcd132f go.tools: use golang.org/x/... import paths
Rewrite performed with this command:
  sed -i '' 's_code.google.com/p/go\._golang.org/x/_g' \
    $(grep -lr 'code.google.com/p/go.' *)

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/170920043
2014-11-10 08:50:40 +11:00
Alan Donovan 9b38eafe60 go/pointer: implement pointer equivalence via hash-value numbering, a pre-solver optimization.
This reduces solver time by about 40%.
See hvn.go for detailed description.

Also in this CL:
- Update package docs.
- Added various global opt/debug options for maintainer convenience.
- Added logging of phase timing.
- Added stdlib_test, disabled by default, that runs the analysis
  on all tests in $GOROOT.
- include types when dumping solution

LGTM=crawshaw
R=crawshaw, dannyb
CC=golang-codereviews
https://golang.org/cl/96650048
2014-06-16 15:46:07 -04:00
Alan Donovan 74117bcfd8 go/pointer: use sparse bit vectors to represent points-to sets in solver.
This optimization reduces solve time (typically >90% of the
total) by about 78% when analysing real programs.  It also
makes the solver 100% deterministic since all iterations are
ordered.

Also:
- remove unnecessary nodeid parameter to solve() method.
- don't add a fieldInfo for singleton tuples (cosmetic fix).
- inline+simplify "worklist" type.
- replace "constraintset" type by a slice.

LGTM=crawshaw
R=crawshaw
CC=golang-codereviews
https://golang.org/cl/95240043
2014-06-11 13:12:15 -04:00
Alan Donovan 829d52f2e8 go.tools/go/callgraph: simplifications to API.
1) We remove context sensitivity from API.  The pointer analysis is
   not sufficiently context-sensitive for the context information to
   be worth exposing.  (The actual analysis precision still benefits
   from being context-sensitive, though.)  Since all clients would
   discard the context info, we now do that for them.
2) Make the graph doubly-linked.  Edges are now shared by the Nodes
   at both ends of the edge so it's possible to navigate more easily
   (e.g. to the callers).
3) Graph and Node are now concrete, not interfaces.

Less code in every file!

LGTM=crawshaw
R=crawshaw
CC=golang-codereviews
https://golang.org/cl/66460043
2014-02-20 11:57:48 -05:00
Alan Donovan 28104d2c91 go.tools/go/pointer: remove context-sensitivity from API.
Previously, each {Indirect,}Query would return a set of Pointers, one per context; now it returns (at most) one Pointer combining information from all contexts.

The old API was more faithful to the implementation concepts, but the analysis is not sufficiently context-sensitive that it makes sense: all existing clients simply throw away the context information---so now we do that for them.

(I may remove the context-sensitivity from the callgraph too, but I'll benchmark that first to see if it reduces precision.)

LGTM=crawshaw
R=crawshaw
CC=golang-codereviews
https://golang.org/cl/66130044
2014-02-20 11:35:09 -05:00
Alan Donovan 03ca00ddd4 go.tools/go/types/typeutil: new package for type utilities.
Contains the members formerly known as:
- ssa.IntuitiveMethodSet
- typemap.M (now: Map)

LGTM=gri
R=gri
CC=golang-codereviews
https://golang.org/cl/65670043
2014-02-19 13:32:36 -05:00
Alan Donovan 5f96644dbf go.tools/pointer: opt: type-based label tracking reduces solver time by up to 75%.
Observation: not all alias facts are interesting.
- A channel-peers query also cares about pointers of kind chan.
- An oracle "points-to" query on an expression of kind map
  only cares about maps.
- We always care about func, interface and reflect.Value,
  since they're needed for sound analysis of dynamic dispatch.

We needn't bother collecting alias information for
uninteresting pointers, and this massively reduces the number
of labels flowing in to the constraint system.
The only constraints that create new labels are addressOf
and offsetAddr; both are now selectively emitted by type.

We compute the set of type kinds to track, based on the
{Indirect,}Query types.  (We could enable tracking at an
even finer grain if we want.)

This requires that we can see all the {Indirect,}Query
value types a priori, which is not the case for the PrintCalls
mechanism used in the tests, so I have rewritten the latter
to use {Indirect,}Query instead.

This reduces the solver-phase time for the entire standard
library and tests from >8m to <2m.  Similar speedups are
obtained on small and medium-sized programs.

Details:
- shouldTrack inspects the flattened form of a type to see if
  it contains fields we must track.  It memoizes the result.
- added precondition checks to (*Config).Add{,Indirect}Query.
- added (*ssa.Program).LookupMethod convenience method.
- added Example of how to use the Query mechanism.
- removed code made dead by a recent invariant:
  the only pointerlike Const value is nil.
- don't generate constraints for any functions in "reflect".
  (we had forgotten to skip synthetic wrappers too).
- write PTA warnings to the log.
- add annotations for more intrinsics.

LGTM=gri, crawshaw
R=crawshaw, gri
CC=golang-codereviews
https://golang.org/cl/62540043
2014-02-18 12:40:44 -08:00
Alan Donovan b856247075 go.tools/call: rename package to go/callgraph
Was:		Now:
call.Graph	callgraph.Graph
call.GraphNode	callgraph.Node
call.Edge	callgraph.Edge

Though call.Graph was cute, the original naming was a mistake:
'call' is too useful a var name to waste on a package.

R=gri, crawshaw
CC=golang-codereviews
https://golang.org/cl/53190043
2014-01-16 14:04:19 -05:00
Alan Donovan 3fc0fc1310 go.tools: rename packages.
Was:		Now:
ssa		go/ssa
importer	go/loader
pointer		go/pointer

Next CL: call -> go/callgraph (requires more care)

R=gri, crawshaw
CC=golang-codereviews
https://golang.org/cl/52960043
2014-01-16 09:33:58 -05:00