Currently we rely on the type-checker to do some basic data-flow
analysis to help decide whether function literals should capture
variables by value or reference. However, this analysis isn't done by
go/types, and escape analysis already has a better framework for doing
this more precisely.
This CL extends escape analysis to recalculate the same "byval" as
CaptureVars and check that it matches. A future CL will remove
CaptureVars in favor of escape analysis's calculation.
Notably, escape analysis happens after deadcode removes obviously
unreachable code, so it sees the AST without any unreachable
assignments. (Also without unreachable addrtakens, but
ComputeAddrtaken already happens after deadcode too.) There are two
test cases where a variable is only reassigned on certain CPUs. This
CL changes them to reassign the variables unconditionally (as no-op
reassignments that avoid triggering cmd/vet's self-assignment check),
at least until we remove CaptureVars.
Passes toolstash -cmp.
Change-Id: I7162619739fedaf861b478fb8d506f96a6ac21f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/281535
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Using statement nodes restricts the set of valid SetOp operations,
because you can't SetOp across representation. Rewrite various
code to avoid crossing those as-yet-unintroduced boundaries.
In particular, code like
x, y := v.(T)
x, y := f()
x, y := m[k]
x, y := <-c
starts out with Op = OAS2, and then it turns into a specific Op
OAS2DOTTYPE, OAS2FUNC, OAS2MAPR, OAS2RECV, and then
later in walk is lowered to an OAS2 again.
In the middle, the specific forms move the right-hand side from
n.Rlist().First() to n.Right(), and then the conversion to OAS2 moves
it back. This is unnecessary and makes it hard for these all to
share an underlying Node implementation.
This CL changes these specific forms to leave the right-hand side
in n.Rlist().First().
Similarly, OSELRECV2 is really just a temporary form of OAS2.
This CL changes it to use same fields too.
Finally, this CL fixes the printing of OAS2 nodes in ir/fmt.go,
which formerly printed n.Right() instead of n.Rlist().
This results in a (correct!) update to cmd/compile/internal/logopt's
expected output: ~R0 = <N> becomes ~R0 = &y.b.
Passes buildall w/ toolstash -cmp.
Change-Id: I164aa2e17dc55bfb292024de53d7d250192ad64a
Reviewed-on: https://go-review.googlesource.com/c/go/+/274105
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
In golang.org/cl/266199, I reused the existing code in inlining that
recognizes anonymous variables. However, it turns out that code
mistakenly recognizes anonymous return parameters as named when
inlining a function from the same package.
The issue is funcargs (which is only used for functions parsed from
source) synthesizes ~r names for anonymous return parameters, but
funcargs2 (which is only used for functions imported from export data)
does not.
This CL fixes the behavior so that anonymous return parameters are
handled identically whether a function is inlined within the same
package or across packages. It also adds a proper cross-package test
case demonstrating #33160 is fixed in both cases.
Change-Id: Iaa39a23f5666979a1f5ca6d09fc8c398e55b784c
Reviewed-on: https://go-review.googlesource.com/c/go/+/266719
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
This CL replaces the ad hoc and duplicated logic for detecting
inlinable calls with a single "inlCallee" function, which uses the
"staticValue" helper function introduced in an earlier commit.
Updates #41474.
Change-Id: I103d4091b10366fce1344ef2501222b7df68f21d
Reviewed-on: https://go-review.googlesource.com/c/go/+/256460
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Trust: Matthew Dempsky <mdempsky@google.com>
Normally, when variables are declared and initialized using ":=", we
set the variable's n.Name.Defn to point to the initialization
assignment node (i.e., OAS or OAS2). Further, some frontend
optimizations look for variables that are initialized but never
reassigned.
However, when inl.go inlines calls, it was declaring the inlined
variables, and then separately assigning to them. This CL changes
inl.go tweaks the AST to fit the combined declaration+initialization
pattern.
This isn't terribly useful by itself, but it allows further followup
optimizations.
Updates #41474.
Change-Id: I62a9752c60414305679e0ed15a6563baa0224efa
Reviewed-on: https://go-review.googlesource.com/c/go/+/256457
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Allow Windows absolute paths, also fixed URI decoding on Windows.
Added a test, reorganized to make the test cleaner.
Also put some doc comments on exported functions that did not have them.
Fixes#41614.
Change-Id: I2871be0e5183fbd53ffb309896d6fe56c15a7727
Reviewed-on: https://go-review.googlesource.com/c/go/+/257677
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Run TestLogOpt for riscv64 on amd64, as is done for other architectures.
This would have caught the test failure on riscv64 introduced in
47ade08141.
Change-Id: If29dea2ef383b087154d046728f6d1c96811f5a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/227806
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This reverts commit 98534812bd.
Reason for revert: The change does not really fixes issue #38251. CL 227497 is real fix.
Change-Id: I9f556005baf1de968f059fb8dad89dae05330aa6
Reviewed-on: https://go-review.googlesource.com/c/go/+/227802
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
For 1.15.
From the test:
{"range":{"start":{"line":7,"character":13},"end":{...},"severity":3,"code":"leaks","source":"go compiler","message":"parameter z leaks to ~r2 with derefs=0","relatedInformation":[
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: flow: y = z:"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: from y = \u003cN\u003e (assign-pair)"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: flow: ~r1 = y:"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":4,"character":11},"end":{...}},"message":"inlineLoc"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: from y.b (dot of pointer)"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":4,"character":11},"end":{...}},"message":"inlineLoc"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: from \u0026y.b (address-of)"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":4,"character":9},"end":...}},"message":"inlineLoc"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":13},"end":{...}},"message":"escflow: from ~r1 = \u003cN\u003e (assign-pair)"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":3},"end":...}},"message":"escflow: flow: ~r2 = ~r1:"},
{"location":{"uri":"file://T/file.go","range":{"start":{"line":9,"character":3},"end":...}},"message":"escflow: from return (*int)(~r1) (return)"}]}
Change-Id: Idf02438801f63e487c35a928cf5a0b6d3cc48674
Reviewed-on: https://go-review.googlesource.com/c/go/+/206658
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
I've been experimenting with this, success is the wrong thing to report
even though it seems to log much less.
Change-Id: I7c25a45d2f41e82b6c8dd8b0a56ba848c63fb21a
Reviewed-on: https://go-review.googlesource.com/c/go/+/223298
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The test was not preserving temporary directory flags leading to a
failure on windows with:
mkdir C:\WINDOWS\go-build315158903: Access is denied.
Fixes#38251
Change-Id: I6ee31b31e84b7f6e75ea6ee0f3b8c094835bf5d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/227497
Reviewed-by: David Chase <drchase@google.com>
For 1.15, unless someone really wants it in 1.14.
A performance-sensitive user thought this would be useful,
though "large" was not well-defined. If 128 is large,
there are 139 static instances of "large" copies in the compiler
itself.
Includes test.
Change-Id: I81f20c62da59d37072429f3a22c1809e6fb2946d
Reviewed-on: https://go-review.googlesource.com/c/go/+/205066
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This is intended to allow IDEs to note where the optimizer
was not able to improve users' code. There may be other
applications for this, for example in studying effectiveness
of optimizer changes more quickly than running benchmarks,
or in verifying that code changes did not accidentally disable
optimizations in performance-critical code.
Logging of nilcheck (bad) for amd64 is implemented as
proof-of-concept. In general, the intent is that optimizations
that didn't happen are what will be logged, because that is
believed to be what IDE users want.
Added flag -json=version,dest
Check that version=0. (Future compilers will support a
few recent versions, I hope that version is always <=3.)
Dest is expected to be one of:
/path (or \path in Windows)
will create directory /path and fill it w/ json files
file://path
will create directory path, intended either for
I:\dont\know\enough\about\windows\paths
trustme_I_know_what_I_am_doing_probably_testing
Not passing an absolute path name usually leads to
json splattered all over source directories,
or failure when those directories are not writeable.
If you want a foot-gun, you have to ask for it.
The JSON output is directed to subdirectories of dest,
where each subdirectory is net/url.PathEscape of the
package name, and each for each foo.go in the package,
net/url.PathEscape(foo).json is created. The first line
of foo.json contains version and context information,
and subsequent lines contains LSP-conforming JSON
describing the missing optimizations.
Change-Id: Ib83176a53a8c177ee9081aefc5ae05604ccad8a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/204338
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
