code review 176780043: cmd/callgraph: add -algo=static and -algo=cha options.

cmd/callgraph: add -algo=static and -algo=cha options.

"static" ignores dynamic calls altogether.

"cha" uses Class Hierarchy Analysis, which assumes that a
dynamic call may dispatch to any func or method that satisfies
the type.

Both these algorithms can work on partial programs,
e.g. libraries without a main function or tests.

(This feature was requested after my talk last night.)

+ Tests.

[adonovan, 2014-11-14 18:45:25]

Hello sameer@golang.org (cc: golang-codereviews@googlegroups.com,
gri@golang.org),

I'd like you to review this change to
https://code.google.com/p/go.tools

[minux, 2014-11-14 19:04:58]

On Fri, Nov 14, 2014 at 1:45 PM, adonovan via golang-codereviews
<golang-codereviews@googlegroups.com> wrote:
> (This feature was requested after my talk last night.)
Is your talk's slides available publicly?

[adonovan, 2014-11-14 19:10:19]

On 14 November 2014 14:04, minux <minux@golang.org> wrote:

> On Fri, Nov 14, 2014 at 1:45 PM, adonovan via golang-codereviews
> <golang-codereviews@googlegroups.com> wrote:
> > (This feature was requested after my talk last night.)
> Is your talk's slides available publicly?
>

I meant to put them up today, but I left my laptop (containing the final
version) at home.  I'll do it before the conference tomorrow.

[Sameer Ajmani, 2014-11-17 20:50:24]

https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go
File cmd/callgraph/main.go (right):

https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go#new...
cmd/callgraph/main.go:191: for f := range ssautil.AllFunctions(prog) {
Consider hoisting this out into a static.CallGraph function for symmetry with
the others, and so you can write a test.

[adonovan, 2014-11-17 21:38:08]

https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go
File cmd/callgraph/main.go (right):

https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go#new...
cmd/callgraph/main.go:191: for f := range ssautil.AllFunctions(prog) {
On 2014/11/17 20:50:23, Sameer Ajmani wrote:
> Consider hoisting this out into a static.CallGraph function for symmetry with
> the others, and so you can write a test.

Done.

[Sameer Ajmani, 2014-11-18 20:23:12]

On 2014/11/17 21:38:08, adonovan wrote:
> https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go
> File cmd/callgraph/main.go (right):
> 
>
https://codereview.appspot.com/176780043/diff/60001/cmd/callgraph/main.go#new...
> cmd/callgraph/main.go:191: for f := range ssautil.AllFunctions(prog) {
> On 2014/11/17 20:50:23, Sameer Ajmani wrote:
> > Consider hoisting this out into a static.CallGraph function for symmetry
with
> > the others, and so you can write a test.
> 
> Done.

LGTM

[adonovan, 2014-11-21 16:07:56]

*** Submitted as
https://code.google.com/p/go/source/detail?r=159a6f08c3a6&repo=tools ***

cmd/callgraph: add -algo=static and -algo=cha options.

"static" ignores dynamic calls altogether.

"cha" uses Class Hierarchy Analysis, which assumes that a
dynamic call may dispatch to any func or method that satisfies
the type.

Both these algorithms can work on partial programs,
e.g. libraries without a main function or tests.

(This feature was requested after my talk last night.)

+ Tests.

LGTM=sameer
R=sameer, minux
CC=golang-codereviews, gri
https://codereview.appspot.com/176780043