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48989 Commits

Author SHA1 Message Date
Robert Griesemer
93285c89d1 [dev.typeparams] cmd/compile/internal/types2: fix range over exprs of type parameter type
For range expressions of type parameter type, the structural type
of the type parameter's constraint determines the range operation.

While at it, rename implicitArrayDeref to arrayPtrDeref.

Change-Id: Ib631a8a14e717498e5264944f659309df1f68cc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/339897
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-06 20:34:45 +00:00
Robert Griesemer
5aac85ad5e [dev.typeparams] cmd/compile/internal/types2: better names for things (cleanup)
- use the symbol 𝓤 (as in 𝓤niverse) instead of ⊤ to denote the set
  of all types (for better readabilty, ⊤ is hard to distinguish from
  T in some fonts)

- use isAll instead of isTop to test for the set of all types

- use allTermlist instead of topTermlist to denote the termlist
  representing all types

Change-Id: Idcb0b3398782b38653338e65173c0dbb935e430a
Reviewed-on: https://go-review.googlesource.com/c/go/+/339891
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-06 20:34:43 +00:00
Dan Scales
110343e4a2 [dev.typeparams] cmd/compile: cleanup wrapper code for generics
Simple change - added some comments, but also removed some TODO comments
which are now done or no longer a question. Cleaned up the initial check
for generic methods.

The one remaining TODO that really needs to be done is generating
dictionary wrappers for any methods involving embedded fields. Given we
are not doing this, I think this would only affect if a struct with an
embedded field with methods was converted to an interface containing the
embedded method, and then the method was called via that interface.

Change-Id: I6a8a2885de33ad60b313c1899b659daef7550dfb
Reviewed-on: https://go-review.googlesource.com/c/go/+/340260
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-08-06 19:33:52 +00:00
Dan Scales
5e33d11e10 [dev.typeparams] cmd/compile: do transformCall with non-shape type of call
Do the transformCall using the original types2-derived type of the call
(in particular, the types of the params as non-shapes). Currently, since
we were using the param types of the instantiation, we might add in
interface conversions to an interface with shapes in the one case of a
full-instantiated generic call. So, we do the transformCall() before
installing the shaped-based instantiation. transformCall() works
correctly even in the case of OCALL/FUNCINST.

Fixed two related bugs:
  - Fixed case where we still were not correctly substituting the types
    for a function instantiation.
  - The type substituter needs to copy field flags while substituting in
    tstruct.

Change-Id: I14e960737d6840a75846ede480e6650534ba3af3
Reviewed-on: https://go-review.googlesource.com/c/go/+/340259
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-08-06 19:13:56 +00:00
Dan Scales
ac78501b9c [dev.typeparams] cmd/compile: make sure closures inside generic funcs are not compiled
Closures inside generic functions were being added to the g.target.Decls
list during noding, just like other closures. We remove generic
functions/methods from g.target.Decls, so they don't get compiled
(they're only available for export and stenciling). Most closures inside
generic functions/methods were similarly being removed from
g.target.Decls, because they have a generic parameter. But we need to
ensure no closures in generic function/methods are left remaining in
g.target.Decls, since we don't want them transformed and compiled.

So, we set a flag in (*irgen) that records when we are noding a
top-level generic function/method, and don't add any closures to
g.target.Decls when the flag is true.

Updates #47514

Change-Id: Id66b4c41d307ffa8f54cab6ce3646ade81606862
Reviewed-on: https://go-review.googlesource.com/c/go/+/340258
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-08-06 18:50:46 +00:00
Jason A. Donenfeld
70546f6404 runtime: allow arm64 SEH to be called if illegal instruction
DLLs built with recent Microsoft toolchains for ARM64 test for ARMv8.1
atomics by potentially calling an illegal instruction, and then trapping
the exception to disable use of them by way of a structured exception
handler. However, vectored exception handlers are always called before
structured exception handlers. When LoadLibrary-ing DLLs that do this
probing during initialization, our lastcontinuehandler winds up being
called, and then crashing, but actually it should give execution back to
the library to handle the exception and fix up the state. So special
case this for arm64 with illegal instructions, and hope that we're not
masking other things in external DLLs that might more fatally trigger an
illegal instruction exception.

Updates #47576.

Change-Id: I341ab99cd8d513ae999b75596749d49779072022
Reviewed-on: https://go-review.googlesource.com/c/go/+/340070
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2021-08-06 16:51:12 +00:00
Matthew Dempsky
fd45e267c2 runtime: warn that KeepAlive is not an unsafe.Pointer workaround
Even experienced users occasionally mistake that runtime.KeepAlive can
be used as a workaround for following the unsafe.Pointer safety rules,
but it cannot. Add an explicit warning to this effect to dissuade
users from trying to use it as such.

Fixes #47562.

Change-Id: I842e33a3e1c080933c6b1bd1b6318448adbf495c
Reviewed-on: https://go-review.googlesource.com/c/go/+/340269
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-08-05 20:22:31 +00:00
Robert Griesemer
f78d538858 [dev.typeparams] cmd/compile/internal/types2: cleanup panic calls
End-users are not expected to deal with the details of panics,
so providing extra information such as an "internal error" prefix
or the name of the function invoking the panic are not helpful.

Remove unnecessary panic verbiage if it is readily available from
a stack trace (such as the function where it happens, and the fact
that is is an "internal error").

Change-Id: I5f86bae6d2cca7c04ce692d17257da7ddee206d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/339969
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-05 19:37:01 +00:00
Robert Griesemer
c5b6c36ddd [dev.typeparams] cmd/compile/internal/types2: remove TestIncompleteInterfaces (cleanup)
TestIncompleteInterfaces is not useful anymore because interface
printing always shows the syntactic type structure of an interface.

Also remove the respective support code in interface printing and
simplify that code.

Move the newDefined and nopos support declarations unchanged into
api_test.go where they are used.

Updates #46167.

Change-Id: I23e303bc4ae4271912ba75f201bd2b7cd4a17b3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/339832
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-05 19:36:56 +00:00
Robert Griesemer
f14908d01b [dev.typeparams] cmd/compile/internal/types2: remove unused gcCompatibilityMode flag (cleanup)
This flag is not needed by types2 (and possibly can also be removed
from go/types). Removed some unnecessary comments along the way.

Updates #46174.

Change-Id: I1a7a99f724205a084d1c9850bce6f6f5d33f83ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/339831
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-05 19:36:52 +00:00
Robert Griesemer
bb5608dd5d [dev.typeparams] cmd/compile/internal/types2: implement type sets with term lists
This CL resolves several known issues and TODOs.

- Represent type sets with term lists and using term list abstractions.

- Represent Unions internally as a list of (syntactical) terms.
  Use term operations to print terms and detect overlapping union
  entries.

- Compute type sets corresponding to unions lazily, on demand.

- Adjust code throughout.

- Adjusted error check in test/typeparam/mincheck.dir/main.go
  to make test pass.

Change-Id: Ib36fb7e1d343c2b6aec51d304f0f7d1ad415f999
Reviewed-on: https://go-review.googlesource.com/c/go/+/338310
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-05 19:36:47 +00:00
Leonard Wang
6dadee759c [dev.typeparams] cmd/compile: unified importReader receiver name to r
Change-Id: Iaf8ec7665282f4f8c0cb09a652e78aa97959274b
Reviewed-on: https://go-review.googlesource.com/c/go/+/340150
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Robert Griesemer <gri@golang.org>
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2021-08-05 18:01:57 +00:00
Dan Scales
5dcb5e2cea [dev.typeparams] cmd/compile: dictionary/shape cleanup
- Removed gcshapeType - we're going with more granular shapes for now, and gradually
   coarsening later if needed.

 - Put in early return in getDictionarySym(), so the entire rest of the
   function can be un-indented by one level.

 - Removed some duplicated infoprint calls, and fixed one infoprint
   message in getGfInfo.

Change-Id: I13acce8fdabdb21e903275b53ff78a1e6a378de2
Reviewed-on: https://go-review.googlesource.com/c/go/+/339901
Trust: Dan Scales <danscales@google.com>
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Reviewed-by: Keith Randall <khr@golang.org>
2021-08-05 17:53:59 +00:00
Dan Scales
3cdf8b429e [dev.typeparams] cmd/compile: fixing case where type arg is an interface
In this case, we can't use an itab for doing a bound call, since we're
converting from an interface to an interface. We do a static or dynamic
type assert in new function assertToBound().

The dynamic type assert in assertToBound() is only needed if a bound is
parameterized. In that case, we must do a dynamic type assert, and
therefore need a dictionary entry for the type bound (see change in
getGfInfo). I'm not sure if we can somehow limit this case, since using
an interface as a type arg AND having the type bound of the type
arg be parameterized is a very unlikely case.

Had to add the TUNION case to parameterizedBy1() (which is only used for
extra checking).

Added a bunch of these test cases to 13.go, which now passes.

Change-Id: Ic22eed637fa879b5bbb46d36b40aaad6f90b9d01
Reviewed-on: https://go-review.googlesource.com/c/go/+/339898
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-08-05 17:33:41 +00:00
Rob Findley
1b708c0260 [dev.typeparams] go/types: remove a stale comment (cleanup)
Remove a stale comment from when the new types.Info API was guarded
behind the typeparams build constraint.

Change-Id: I319ad0a9e4e4958efdb96c967bf13a0119b5647b
Reviewed-on: https://go-review.googlesource.com/c/go/+/340010
Trust: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
2021-08-04 23:24:01 +00:00
Rob Findley
0ec2a8b42d [dev.typeparams] go/types: switch the TArgs API to NumTArgs/TArg
As with other go/types APIs, we should not expose the underlying
Named.targs slice.

Change-Id: Iba869298fbd3856022ffe8ec2c3273341598c324
Reviewed-on: https://go-review.googlesource.com/c/go/+/340009
Trust: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
2021-08-04 23:23:45 +00:00
Robert Griesemer
e5fe769be1 [dev.typeparams] cmd/compile/internal/types2: implement term lists
Prerequisite for clean implementation of type sets
on top of term lists.

Change-Id: Ice87f2f47327aa6b1f3eaad7f9af20ad7c548155
Reviewed-on: https://go-review.googlesource.com/c/go/+/339596
Trust: Robert Griesemer <gri@golang.org>
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Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-04 21:01:48 +00:00
Keith Randall
b730a26729 [dev.typeparams] cmd/compile: put shape types in their own package
Put shape types in the top level package called ".shape".
Name them using the serialization of the shape name, instead of
the .shapeN names.

This allows the linker to deduplicate instantiations across packages.

Not sure that this is entirely correct, as shapes in this package
may reference other packages (e.g. a field of a struct). But it seems
to work for now.

For the added test, when you look at the resulting binary (use the -k
option with run.go) it has only one instantiation of F, and 4 call sites:

$ objdump -d a.exe | grep _a\.F
 1053cb0:	e8 8b 00 00 00 	callq	139 <_a.F[.shape.*uint8]>
 1053ce9:	e8 52 00 00 00 	callq	82 <_a.F[.shape.*uint8]>
_a.F[.shape.*uint8]:
 1053d90:	e8 ab ff ff ff 	callq	-85 <_a.F[.shape.*uint8]>
 1053dc9:	e8 72 ff ff ff 	callq	-142 <_a.F[.shape.*uint8]>

Change-Id: I627f7e50210aabe4a10d0e2717d87b75ac82e99b
Reviewed-on: https://go-review.googlesource.com/c/go/+/339595
Trust: Keith Randall <khr@golang.org>
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2021-08-04 17:56:00 +00:00
Austin Clements
e590cb64f9 [dev.typeparams] runtime: handle d.link carefully when freeing a defer
CL 339396 allowed stack copying on entry to and during freedefer, but
this introduced a subtle bug: if d is heap-allocated, and d.link
points to a stack-allocated defer, stack copying during freedefer can
briefly introduce a stale pointer, which the garbage collector can
discover and panic about. This happens because d has already been
unlinked from the defer chain when freedefer is called, so stack
copying won't update stack pointers in it.

Fix this by making freedefer nosplit again and immediately clearing
d.link.

This should fix the longtest builders, which currently fail on
GOMAXPROCS=2 runtime -cpu=1,2,4 -quick in the TestDeferHeapAndStack
test.

This seems like the simplest fix, but it just deals with the subtlety
rather than eliminating it. Really, every call site of freedefer (of
which there are surprisingly many) has hidden subtlety between
unlinking the defer and calling freedefer. We could consolidate the
subtlety into each call site by requiring that they unlink the defer
and set d.link to nil before calling freedefer. freedefer could check
this condition like it checks that various other fields have already
been zeroed. A more radical option is to replace freedefer with
"popDefer", which would both pop the defer off the link and take care
of freeing it. There would still be a brief moment of subtlety, but it
would be in one place, in popDefer. Annoyingly, *almost* every call to
freedefer just pops the defer from the head of the G's list, but
there's one place when handling open-coded defers where we have to
remove a defer from the middle of the list. I'm inclined to first fix
that subtlety by only expanding open-coded defer records when they're
at the head of the defer list, and then revisit the popDefer idea.

Change-Id: I3130d2542c01a421a5d60e8c31f5379263219627
Reviewed-on: https://go-review.googlesource.com/c/go/+/339730
Trust: Austin Clements <austin@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-08-04 15:51:58 +00:00
Damien Neil
6e738868a7 net/http: speed up and deflake TestCancelRequestWhenSharingConnection
This test made many requests over the same connection for 10
seconds, trusting that this will exercise the request cancelation
race from #41600.

Change the test to exhibit the specific race in a targeted fashion
with only two requests.

Updates #41600.
Updates #47016.

Change-Id: If99c9b9331ff645f6bb67fe9fb79b8aab8784710
Reviewed-on: https://go-review.googlesource.com/c/go/+/339594
Trust: Damien Neil <dneil@google.com>
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Reviewed-by: Heschi Kreinick <heschi@google.com>
2021-08-04 15:26:45 +00:00
Rob Findley
d27a889119 [dev.typeparams] go/types: move instance.go contents into named.go (cleanup)
This is a port of CL 338469 to go/types.

Change-Id: I3ee655fa2dc7e789f210c8dec171b3358c4ff132
Reviewed-on: https://go-review.googlesource.com/c/go/+/339677
Trust: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
2021-08-04 11:07:34 +00:00
Rob Findley
b01e775e9c [dev.typeparams] go/types: print constraint info for type param operands
This is a clean port of CL 338309 to go/types.

Change-Id: Ie2c9e2ea51d6321af8bf149e43cd71b7ac282d13
Reviewed-on: https://go-review.googlesource.com/c/go/+/339676
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2021-08-04 11:07:26 +00:00
Rob Findley
3efc8f9a8d [dev.typeparams] go/types: (TypeParam) SetBound -> SetConstraint
This is a straightforward port of CL 338196 to go/types, minus the
deprecated TypeParam.Bound() method (since it is not needed), plus an
adjustment for methodset.go.

Change-Id: Ie372bfeec245094102a2c3257a43499d75981447
Reviewed-on: https://go-review.googlesource.com/c/go/+/339675
Trust: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
2021-08-04 11:07:19 +00:00
Rob Findley
ed3667d079 [dev.typeparams] go/types: use type terms to represent unions
This is a straightforward port of CL 338092 to go/types.

Change-Id: I414ec0ad95648c201e85fd2b4f494b1206c658e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/339674
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2021-08-04 11:07:13 +00:00
Rob Findley
880ab6209e [dev.typeparams] cmd/compile/internal/types2: fix a panic in missingMethod
When static == false, missingMethod incorrectly continues with a nil
Func.

Also remove some unnecessary type names from typeterm_test.go, which was
done in the go/types port.

Change-Id: I21fa637ac82b115563d3601314a470a5a43f9ae0
Reviewed-on: https://go-review.googlesource.com/c/go/+/339672
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2021-08-04 11:07:03 +00:00
Rob Findley
5b51cf47dc [dev.typeparams] go/types: implement type terms
This is a port of CL 338049 to go/types. It identical to that CL, except
for eliding unnecessary typenames from the testTerms declaration.

Change-Id: Ieb04d7bbc20063044eb63ea985f75d529f030cd7
Reviewed-on: https://go-review.googlesource.com/c/go/+/339653
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2021-08-04 11:06:37 +00:00
Rob Findley
e0d0907212 [dev.typeparams] go/types: use comparable bit rather than ==() method
This is a port of CL 337354 to go/types, adjusted for the error
reporting API and to reposition a couple error messages in
issue47411.go2 (the go/types position is probably better).

A panic is also fixed in lookup.go when method lookup fails and static
== false. I'll send a fix for types2 in a separate CL.

For #47411

Change-Id: Icc48f03c3958695f581f10e8675c1f32434c424b
Reviewed-on: https://go-review.googlesource.com/c/go/+/339652
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2021-08-04 11:06:24 +00:00
Rob Findley
18e0503724 [dev.typeparams] go/types: embedded type cannot be a (pointer to) a type parameter
This is a port of CL 337353 to go/types, adjusted for the error API and
to comment out a test for MethodSet.

Some nearby error messages that were using errorf rather than error were
also adjusted.

Fixes #43621

Change-Id: I28c9747e044ec7a2863f6890db69475fb8c29231
Reviewed-on: https://go-review.googlesource.com/c/go/+/339651
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2021-08-04 11:06:10 +00:00
Rob Findley
89897473e2 [dev.typeparams] go/types: implement TypeParam.Constraint
This is a clean port of CL 336989 to go/types.

Change-Id: Ib8dbe03f420d28ada6d5fc7003ab0c82c7e06c41
Reviewed-on: https://go-review.googlesource.com/c/go/+/339650
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2021-08-04 11:05:55 +00:00
Rob Findley
1ea3596b41 [dev.typeparams] go/types: adjust unsafe.Alignof/Offsetof/Sizeof
This is a port of CL 335413 to go/types, adjusted for the parsing API of
go/parser.

Change-Id: Ie6836add7d027aaf5d6d3dae65222b1d15bd7558
Reviewed-on: https://go-review.googlesource.com/c/go/+/339649
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2021-08-04 11:05:47 +00:00
Austin Clements
88bd92bb6d [dev.typeparams] runtime: simplify freedefer
Currently, freedefer manually zeros all the fields in the _defer
because simply assigning _defer{} used to cause a nosplit stack
overflow. freedefer is no longer nosplit, so go back to the simpler,
more robust code.

Change-Id: I881f557bab3b1ee7ab29b68e7fb56d0fe6d35d8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/339669
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2021-08-03 21:23:25 +00:00
Austin Clements
1a0630aef4 [dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop
Currently, deferreturn runs deferred functions by backing up its
return PC to the deferreturn call, and then effectively tail-calling
the deferred function (via jmpdefer). The effect of this is that the
deferred function appears to be called directly from the deferee, and
when it returns, the deferee calls deferreturn again so it can run the
next deferred function if necessary.

This unusual flow control leads to a large number of special cases and
complications all over the tool chain.

This used to be necessary because deferreturn copied the deferred
function's argument frame directly into its caller's frame and then
had to invoke that call as if it had been called from its caller's
frame so it could access it arguments. But now that we've simplified
defer processing so the runtime only deals with argument-less
closures, this approach is no longer necessary.

This CL simplifies all of this by making deferreturn simply call
deferred functions in a loop.

This eliminates the need for jmpdefer, so we can delete a bunch of
per-architecture assembly code.

This eliminates several special cases on Wasm, since it couldn't
support these calling shenanigans directly and thus had to simulate
the loop a different way. Now Wasm can largely work the way the other
platforms do.

This eliminates the per-architecture Ginsnopdefer operation. On PPC64,
this was necessary to reload the TOC pointer after the tail call
(since TOC pointers in general make tail calls impossible). The tail
call is gone, and in the case where we do force a jump to the
deferreturn call when recovering from an open-coded defer, we go
through gogo (via runtime.recovery), which handles the TOC. On other
platforms, we needed a NOP so traceback didn't get confused by seeing
the return to the CALL instruction, rather than the usual return to
the instruction following the CALL instruction. Now we don't inject a
return to the CALL instruction at all, so this NOP is also
unnecessary.

The one potential effect of this is that deferreturn could now appear
in stack traces from deferred functions. However, this could already
happen from open-coded defers, so we've long since marked deferreturn
as a "wrapper" so it gets elided not only from printed stack traces,
but from runtime.Callers*.

This is a retry of CL 337652 because we had to back out its parent.
There are no changes in this version.

Change-Id: I3f54b7fec1d7ccac71cc6cf6835c6a46b7e5fb6c
Reviewed-on: https://go-review.googlesource.com/c/go/+/339397
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-08-03 21:05:55 +00:00
Austin Clements
077925e2b0 [dev.typeparams] runtime: remove unnecessary split-prevention from defer code
Prior to regabi, the compiler passed defer arguments to the runtime as
untyped values on the stack. This meant a lot of defer-related runtime
functions had to be very careful not to grow the stack or allow
preemption since the stack could not be safely scanned or moved.
However, with regabi, every defer is now simply a func() from the
runtime's perspective, which means we no longer have untyped values on
the stack when we enter defer-related runtime code.

Hence, this CL removes a lot of the now-unnecessary carefulness in the
defer implementation. Specifically, deferreturn no longer needs to be
nosplit because it doesn't copy untyped defer arguments to its
caller's frame (we also update some stale comments in deferreturn).
freedefer no longer needs to be nosplit because it's none of its
callers are deeply nosplit. And newdefer and freedefer no longer need
to switch to the systemstack on their slow paths to avoid stack
growth.

deferprocStack is the only function that still needs to be nosplit,
but that's because the compiler calls it with uninitialized live
pointer slots on the stack (maybe we should change that, but that's a
very different fix).

This is a retry of CL 337651, which was rolled back. This version
disables preemption in newdefer and freedefer while they hold the
current P.

Change-Id: Ibf469addc0b69dc3ba9a3d1a5e0c2804b7b4b244
Reviewed-on: https://go-review.googlesource.com/c/go/+/339396
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-08-03 21:05:54 +00:00
Matthew Dempsky
7ab8754029 [dev.typeparams] cmd/compile: avoid redundant method wrappers in unified IR
Currently, unified IR takes a simple approach of generating method
wrappers for every anonymous type that it sees. This is correct, but
spends a lot of time in code generation and bloats the object files
with duplicate method wrappers that the linker discards.

This CL changes it to distinguish anonymous types that were found in
imported packages vs the local package. The simple win here is that
now we stop emitting wrappers for imported types; but by keeping track
of them and marking them as "have" instead of "need", we can avoid
emitting wrappers for types that appear in both the local package and
imported packages.

This can be improved further, but this is a simple first step that
prevents large protobuf projects from blowing up build cache limits.

Change-Id: Ia65e8981cb1f067eca2bd072b9bbb77c27b95207
Reviewed-on: https://go-review.googlesource.com/c/go/+/339411
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
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Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-08-03 19:01:04 +00:00
Matthew Dempsky
fe73f28dc5 [dev.typeparams] cmd/compile: set sym.Def to ir.Name for method value wrappers
The code for generating method value wrappers is weird that it sets
sym.Def to the generated ir.Func, whereas normally sym.Def points to
ir.Name.

While here, change methodValueWrapper to return the ir.Name too, since
that's what the caller wants.

Change-Id: I3da5320ca0bf4d32d7b420345454f19075d19a26
Reviewed-on: https://go-review.googlesource.com/c/go/+/339410
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
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Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-08-03 19:00:56 +00:00
Cherry Mui
656f0888b7 [dev.typeparams] cmd/compile: make softfloat mode work with register ABI
Previously, softfloat mode does not work with register ABI, mainly
because the compiler doesn't know how to pass floating point
arguments and results. According to the ABI it should be passed in
FP registers, but there isn't any in softfloat mode.

This CL makes it work. When softfloat is used, we define the ABI
as having 0 floating point registers (because there aren't any).
The integer registers are unchanged. So floating point arguments
and results are passed in memory.

Another option is to pass (the bit representation of) floating
point values in integer registers. But this complicates things
because it'd need to reorder integer argument registers.

Change-Id: Ibecbeccb658c10a868fa7f2dcf75138f719cc809
Reviewed-on: https://go-review.googlesource.com/c/go/+/327274
Trust: Cherry Mui <cherryyz@google.com>
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Reviewed-by: David Chase <drchase@google.com>
2021-08-03 16:14:24 +00:00
Matthew Dempsky
1b193598b3 [dev.typeparams] cmd/compile: fail early on unexpected types2.Invalid
In unified IR, fail right away if we find a types2.Invalid while
writing out the package. This provides a clearer error message for
https://github.com/golang/go/issues/25838#issuecomment-448746670.

Updates #25838.

Change-Id: I6902fdd891fc31bbb832b6fdba00eca301282409
Reviewed-on: https://go-review.googlesource.com/c/go/+/338973
Trust: Matthew Dempsky <mdempsky@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
2021-08-03 02:42:15 +00:00
Dan Scales
e56234a305 [dev.typeparams] cmd/compile: simple shape cleanups
- Changed some early returns to asserts (instantiateMethods and Shapify
   should never take a shape arg)

 - Added suggested change (by Ingo) to use copy() in getInstantiation()

 - Clarified that shape types never have methods in Shapify(), removed
   some TODO comments.

Change-Id: Ia2164ffe670a777f7797bbb45c7ef5e6e9e15357
Reviewed-on: https://go-review.googlesource.com/c/go/+/338971
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
2021-08-02 21:26:07 +00:00
Robert Griesemer
c3c19731a9 [dev.typeparams] cmd/compile/internal/types2: move instance.go contents into named.go (cleanup)
This just moves the code around the instance type into named.go
where it belongs. While at it, also removed some left-over references
to instance types (which are gone). Removed instance.go.

Change-Id: I302a86ca50675b0be54f6138fa47f48f00f9c98f
Reviewed-on: https://go-review.googlesource.com/c/go/+/338469
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-02 21:08:34 +00:00
Dan Scales
156eeb40a6 [dev.typeparams] cmd/compile: make HasShape() more efficient by implementing with a type flag
Implement HasShape() similar to how HasTParam() is implemented.

Fixes #47456

Change-Id: Icbd538574237faad2c4cd8c8e187725a1df47637
Reviewed-on: https://go-review.googlesource.com/c/go/+/339029
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
2021-08-02 17:51:34 +00:00
Ian Lance Taylor
8a7ee4c51e io/fs: don't use absolute path in DirEntry.Name doc
Fixes #47485

Change-Id: I64ac00905a403b7594c706141679051a93058a31
Reviewed-on: https://go-review.googlesource.com/c/go/+/338889
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
2021-08-02 17:18:57 +00:00
Robert Griesemer
283991bd7f [dev.typeparams] cmd/compile/internal/types2: print constraint info for type param operands
Change-Id: Ic7a249fc150b526835db744431bef500c20fbd26
Reviewed-on: https://go-review.googlesource.com/c/go/+/338309
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-08-02 16:16:21 +00:00
Cherry Mui
aa3d54da07 [dev.typeparams] runtime: rewrite softfloat functions to avoid using floats
Currently, most softfloat functions take uint32/64 arguments (for
bit representation of float32/64) and operate on uint32/64. But
there are exeptions where the function take float arguments and
operate on float. So they are only actually softfloat if the
helper functions themselves are translated (by the compiler's
softfloat mode). These are mostly fine (besides being a bit
convoluted). But with register ABIs this inconsistency adds
complexity to the compiler to generate such calls, because it
needs to be called with the right ABI.

Rewrite the functions to operate on uint32/64 directly, using
other helper functions. So they all take uint32/64 arguments and
return uint32/64.

Change-Id: Id9383b74bcbafee44160cc5b58ab245bffbbdfd2
Reviewed-on: https://go-review.googlesource.com/c/go/+/327273
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2021-08-02 16:09:19 +00:00
Josh Bleecher Snyder
b8ca6e59ed all: gofmt
Change-Id: Icfafcfb62a389d9fd2e7a4d17809486ed91f15c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/338629
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-07-31 23:59:40 +00:00
Keith Randall
0b8a9ccb25 [dev.typeparams] cmd/compile: make all pointer types have the same shape
Except unsafe.Pointer. It has a different Kind, which makes it trickier.

Change-Id: I12582afb6e591bea35da9e43ac8d141ed19532a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/338749
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
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Reviewed-by: Dan Scales <danscales@google.com>
2021-07-31 17:03:07 +00:00
Austin Clements
7bed50e667 [dev.typeparams] Revert "[dev.typeparams] runtime: remove unnecessary split-prevention from defer code"
This reverts CL 337651.

This causes `go test -count 1000 -run TestDeferHeapAndStack runtime`
to fail with a SIGSEGV freedefer
[https://build.golang.org/log/c113b366cc6d51146db02a07b4d7dd931133efd5]
and possibly sometimes a GC bad pointer panic
[https://build.golang.org/log/5b1cef7a9ad68704e9ef3ce3ad2fefca3ba86998].

Change-Id: Ie56c274b78603c81191213b302225ae19de27fb9
Reviewed-on: https://go-review.googlesource.com/c/go/+/338710
Trust: Austin Clements <austin@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-07-30 21:51:50 +00:00
Austin Clements
e3e9f0bb2d [dev.typeparams] Revert "[dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop"
This reverts CL 227652.

I'm reverting CL 337651 and this builds on top of it.

Change-Id: I03ce363be44c2a3defff2e43e7b1aad83386820d
Reviewed-on: https://go-review.googlesource.com/c/go/+/338709
Trust: Austin Clements <austin@google.com>
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2021-07-30 21:51:49 +00:00
Keith Randall
40e561d933 [dev.typeparams] cmd/compile: allow types with the same underlying type to have the same shape
First baby step to sharing the underlying implementation among several types.

Change-Id: I6a156176d2b7f0131a87285a03b881ce380c26ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/338610
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
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2021-07-30 21:01:32 +00:00
Austin Clements
fd0011dca5 [dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop
Currently, deferreturn runs deferred functions by backing up its
return PC to the deferreturn call, and then effectively tail-calling
the deferred function (via jmpdefer). The effect of this is that the
deferred function appears to be called directly from the deferee, and
when it returns, the deferee calls deferreturn again so it can run the
next deferred function if necessary.

This unusual flow control leads to a large number of special cases and
complications all over the tool chain.

This used to be necessary because deferreturn copied the deferred
function's argument frame directly into its caller's frame and then
had to invoke that call as if it had been called from its caller's
frame so it could access it arguments. But now that we've simplified
defer processing so the runtime only deals with argument-less
closures, this approach is no longer necessary.

This CL simplifies all of this by making deferreturn simply call
deferred functions in a loop.

This eliminates the need for jmpdefer, so we can delete a bunch of
per-architecture assembly code.

This eliminates several special cases on Wasm, since it couldn't
support these calling shenanigans directly and thus had to simulate
the loop a different way. Now Wasm can largely work the way the other
platforms do.

This eliminates the per-architecture Ginsnopdefer operation. On PPC64,
this was necessary to reload the TOC pointer after the tail call
(since TOC pointers in general make tail calls impossible). The tail
call is gone, and in the case where we do force a jump to the
deferreturn call when recovering from an open-coded defer, we go
through gogo (via runtime.recovery), which handles the TOC. On other
platforms, we needed a NOP so traceback didn't get confused by seeing
the return to the CALL instruction, rather than the usual return to
the instruction following the CALL instruction. Now we don't inject a
return to the CALL instruction at all, so this NOP is also
unnecessary.

The one potential effect of this is that deferreturn could now appear
in stack traces from deferred functions. However, this could already
happen from open-coded defers, so we've long since marked deferreturn
as a "wrapper" so it gets elided not only from printed stack traces,
but from runtime.Callers*.

Change-Id: Ie9f700cd3fb774f498c9edce363772a868407bf7
Reviewed-on: https://go-review.googlesource.com/c/go/+/337652
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-07-30 18:49:44 +00:00
Austin Clements
53fd5b1b77 [dev.typeparams] runtime: remove unnecessary split-prevention from defer code
Prior to regabi, the compiler passed defer arguments to the runtime as
untyped values on the stack. This meant a lot of defer-related runtime
functions had to be very careful not to grow the stack or allow
preemption since the stack could not be safely scanned or moved.
However, with regabi, every defer is now simply a func() from the
runtime's perspective, which means we no longer have untyped values on
the stack when we enter defer-related runtime code.

Hence, this CL removes a lot of the now-unnecessary carefulness in the
defer implementation. Specifically, deferreturn no longer needs to be
nosplit because it doesn't copy untyped defer arguments to its
caller's frame (we also update some stale comments in deferreturn).
freedefer no longer needs to be nosplit because it's none of its
callers are deeply nosplit. And newdefer and freedefer no longer need
to switch to the systemstack on their slow paths to avoid stack
growth.

deferprocStack is the only function that still needs to be nosplit,
but that's because the compiler calls it with uninitialized live
pointer slots on the stack (maybe we should change that, but that's a
very different fix).

Change-Id: I1156ec90bff2613fe4b48b84b375943349ce637d
Reviewed-on: https://go-review.googlesource.com/c/go/+/337651
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-07-30 18:49:42 +00:00