delta/go-git.git/src/cmd/internal/obj, branch dev.cmdgo

cmd/internal/obj/arm64: disable the pre and post index formats for pseudo registers

2021-08-20T03:25:17+00:00

When using the FP or SP pseudo-register to load or store, pre-index and post-index formats
are not supported because the RSP and pseudo registers are not allowed to be modified in this
way. This CL deletes the related entries in optab and adds a few test cases.

Change-Id: Ie30d27d0e7b959242f0e6298b950489669d07989
Reviewed-on: https://go-review.googlesource.com/c/go/+/342770
Reviewed-by: eric fang 
Reviewed-by: Cherry Mui 
Run-TryBot: eric fang 
Trust: Michael Knyszek

cmd/internal/obj/arm64: don't use REGTMP when moving C_AACON2 to a register

2021-08-18T02:07:22+00:00

MOVD $C_AACON2(Rf), Rt is encoded as ADD $C_AACON2_high_12_bits, Rf, REGTMP +
ADD $C_AACON2_low_12_bits, REGTMP, Rt. Actually REGTMP is not necessary here,
we can use Rt directly, so it becomes ADD $C_AACON2_high_12_bits, Rf, Rt +
ADD $C_AACON2_low_12_bits, Rt, Rt.

Change-Id: I90b7718b5fb0ab9f3ea28511f42946a6bdccfef3
Reviewed-on: https://go-review.googlesource.com/c/go/+/329751
Reviewed-by: eric fang 
Reviewed-by: Cherry Mui 
Trust: eric fang 
Run-TryBot: eric fang

cmd/internal/obj/arm64: fix the encoding error when operating with ZR

2021-08-18T02:06:51+00:00

Some arm64 instructions accept ZR as its destination register, such as MOVD,
AND, ADD etc. although it doesn't seem to make much sense, but we should
make sure the encoding is correct. However there exists some encoding mistakes
in the current assembler, they are:
1, 'MOVD $1, ZR' is incorrectly encoded as 'MOVD $1, ZR' + '0x00000000'.
2, 'AND $1, R2, ZR' is incorrectly encoded as 'MOVD $1, R27' + 'AND R27, R2, ZR' +
   '0x00000000'.
3, 'AND $1, ZR' is incorrectly encoded as 'AND $1, ZR, RSP'.

Obviously the first two encoding errors can cause SIGILL, and the third one will
rewrite RSP.

At the same time, I found some weird encodings but they don't cause errors.
4, 'MOVD $0x0001000100010001, ZR' is encoded as 'MOVW $1, ZR' + 'MOVKW $(1<<16), ZR'.
5, 'AND $0x0001000100010001, R2, ZR' is encoded as 'MOVD $1, R27' + 'MOVK $(1<<16), R27' +
   'MOVK $(1<<32), R27'.

Some of these issues also apply to 32-bit versions of these instructions.

These problems are not very complicated, and are basically caused by the improper
adaptation of the class of the constant to the entry in the optab. But the relationship
between these constant classes is a bit complicated, so I don't know how to deal with
issue 4 and 5, because they won't cause errors, so this CL didn't deal with them.

This CL fixed the first three issues.
Issue 1:
  before: 'MOVD $1, ZR' => 'MOVD $1, ZR' + '0x00000000'.
  after:  'MOVD $1, ZR' => 'MOVD $1, ZR'.
Issue 2:
  before: 'AND $1, R2, ZR' => 'MOVD $1, R27' + 'AND R27, R2, ZR' + '0x00000000'.
  after:  'AND $1, R2, ZR' => 'ORR $1, ZR, R27' + 'AND R27, R2, ZR'.
Issue 3:
  before: 'AND $1, ZR' => 'AND $1, ZR, RSP'.
  after:  'AND $1, ZR' => 'ORR $1, ZR, R27' + 'AND R27, ZR, ZR'.

Change-Id: I3c889079229f847b863ad56c88966be12d947202
Reviewed-on: https://go-review.googlesource.com/c/go/+/329750
Reviewed-by: eric fang 
Reviewed-by: Cherry Mui 
Trust: eric fang 
Run-TryBot: eric fang 
TryBot-Result: Go Bot

[dev.typeparams] all: merge master (46fd547) into dev.typeparams

2021-08-12T19:43:12+00:00

Conflicts:

- src/go/types/check_test.go

  CL 324730 on dev.typeparams changed the directory paths in TestCheck,
  TestExamples, and TestFixedbugs and renamed checkFiles to testFiles;
  whereas CL 337529 on master added a new test case just above them and
  that used checkFiles.

Merge List:

+ 2021-08-12 46fd547d89 internal/goversion: update Version to 1.18
+ 2021-08-12 5805efc78e doc/go1.17: remove draft notice
+ 2021-08-12 39634e7dae CONTRIBUTORS: update for the Go 1.17 release
+ 2021-08-12 095bb790e1 os/exec: re-enable LookPathTest/16
+ 2021-08-11 dea23e9ca8 src/make.*: make --no-clean flag a no-op that prints a warning
+ 2021-08-11 d4c0ed26ac doc/go1.17: linker passes -I to extld as -Wl,--dynamic-linker
+ 2021-08-10 1f9c9d8530 doc: use "high address/low address" instead of "top/bottom"
+ 2021-08-09 f1dce319ff cmd/go: with -mod=vendor, don't panic if there are duplicate requirements
+ 2021-08-09 7aeaad5c86 runtime/cgo: when using msan explicitly unpoison cgoCallers
+ 2021-08-08 507cc341ec doc: add example for conversion from slice expressions to array ptr
+ 2021-08-07 891547e2d4 doc/go1.17: fix a typo introduced in CL 335135
+ 2021-08-06 8eaf4d16bc make.bash: do not overwrite GO_LDSO if already set
+ 2021-08-06 63b968f4f8 doc/go1.17: clarify Modules changes
+ 2021-08-06 70546f6404 runtime: allow arm64 SEH to be called if illegal instruction
+ 2021-08-05 fd45e267c2 runtime: warn that KeepAlive is not an unsafe.Pointer workaround
+ 2021-08-04 6e738868a7 net/http: speed up and deflake TestCancelRequestWhenSharingConnection
+ 2021-08-02 8a7ee4c51e io/fs: don't use absolute path in DirEntry.Name doc
+ 2021-07-31 b8ca6e59ed all: gofmt
+ 2021-07-30 b7a85e0003 net/http/httputil: close incoming ReverseProxy request body
+ 2021-07-29 70fd4e47d7 runtime: avoid possible preemption when returning from Go to C
+ 2021-07-28 9eee0ed439 cmd/go: fix go.mod file name printed in error messages for replacements
+ 2021-07-28 b39e0f461c runtime: don't crash on nil pointers in checkptrAlignment
+ 2021-07-27 7cd10c1149 cmd/go: use .mod instead of .zip to determine if version has go.mod file
+ 2021-07-27 c8cf0f74e4 cmd/go: add missing flag in UsageLine
+ 2021-07-27 7ba8e796c9 testing: clarify T.Name returns a distinct name of the running test
+ 2021-07-27 33ff155970 go/types: preserve untyped constants on the RHS of a shift expression
+ 2021-07-26 840e583ff3 runtime: correct variable name in comment
+ 2021-07-26 bfbb288574 runtime: remove adjustTimers counter
+ 2021-07-26 9c81fd53b3 cmd/vet: add missing copyright header

Change-Id: Ia80604d24c6f4205265683024e3100769cf32065

doc: use "high address/low address" instead of "top/bottom"

2021-08-10T01:13:06+00:00

The current document uses the "top" and "bottom" when talking
about the address within a frame, which may easily lead to
misunderstandings. This patch directly uses "high address"
and "low address" to make the expression clearer.

Change-Id: I7469330bbdc158672d7f0314fe6680ebdd9ab79a
Reviewed-on: https://go-review.googlesource.com/c/go/+/339369
Trust: fannie zhang 
Reviewed-by: Austin Clements 
Reviewed-by: Cherry Mui

[dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop

2021-08-03T21:05:55+00:00

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 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui

[dev.typeparams] Revert "[dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop"

2021-07-30T21:51:49+00:00

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 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui

[dev.typeparams] runtime,cmd/compile,cmd/link: replace jmpdefer with a loop

2021-07-30T18:49:44+00:00

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 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui

[dev.typeparams] cmd/compile: introduce named gcshape types

2021-07-21T21:04:15+00:00

Still 1-1 with real types, but now with their own names!

Shape types are implicitly convertible to (and convertible from)
the types they represent.

Change-Id: I0133a8d8fbeb369380574b075a32b3c987e314d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/335170
Run-TryBot: Keith Randall 
Trust: Keith Randall 
Trust: Dan Scales 
Reviewed-by: Dan Scales

[dev.typeparams] all: merge master (4711bf3) into dev.typeparams

2021-07-01T01:28:34+00:00

Conflicts:

- src/cmd/compile/internal/walk/builtin.go

  On dev.typeparams, CL 330194 changed OCHECKNIL to not require manual
  SetTypecheck(1) anymore; while on master, CL 331070 got rid of the
  OCHECKNIL altogether by moving the check into the runtime support
  functions.

- src/internal/buildcfg/exp.go

  On master, CL 331109 refactored the logic for parsing the
  GOEXPERIMENT string, so that it could be more easily reused by
  cmd/go; while on dev.typeparams, several CLs tweaked the regabi
  experiment defaults.

Merge List:

+ 2021-06-30 4711bf30e5 doc/go1.17: linkify "language changes" in the runtime section
+ 2021-06-30 ed56ea73e8 path/filepath: deflake TestEvalSymlinksAboveRoot on darwin
+ 2021-06-30 c080d0323b cmd/dist: pass -Wno-unknown-warning-option in swig_callback_lto
+ 2021-06-30 7d0e9e6e74 image/gif: fix typo in the comment (io.ReadByte -> io.ByteReader)
+ 2021-06-30 0fa3265fe1 os: change example to avoid deprecated function
+ 2021-06-30 d19a53338f image: add Uniform.RGBA64At and Rectangle.RGBA64At
+ 2021-06-30 c45e800e0c crypto/x509: don't fail on optional auth key id fields
+ 2021-06-29 f9d50953b9 net: fix failure of TestCVE202133195
+ 2021-06-29 e294b8a49e doc/go1.17: fix typo "MacOS" -> "macOS"
+ 2021-06-29 3463852b76 math/big: fix typo of comment (`BytesScanner` to `ByteScanner`)
+ 2021-06-29 fd4b587da3 cmd/compile: suppress details error for invalid variadic argument type
+ 2021-06-29 e2e05af6e1 cmd/internal/obj/arm64: fix an encoding error of CMPW instruction
+ 2021-06-28 4bb0847b08 cmd/compile,runtime: change unsafe.Slice((*T)(nil), 0) to return []T(nil)
+ 2021-06-28 1519271a93 spec: change unsafe.Slice((*T)(nil), 0) to return []T(nil)
+ 2021-06-28 5385e2386b runtime/internal/atomic: drop Cas64 pointer indirection in comments
+ 2021-06-28 956c81bfe6 cmd/go: add GOEXPERIMENT to `go env` output
+ 2021-06-28 a1d27269d6 cmd/go: prep for 'go env' refactoring
+ 2021-06-28 901510ed4e cmd/link/internal/ld: skip the windows ASLR test when CGO_ENABLED=0
+ 2021-06-28 361159c055 cmd/cgo: fix 'see gmp.go' to 'see doc.go'
+ 2021-06-27 c95464f0ea internal/buildcfg: refactor GOEXPERIMENT parsing code somewhat
+ 2021-06-25 ed01ceaf48 runtime/race: use race build tag on syso_test.go
+ 2021-06-25 d1916e5e84 go/types: in TestCheck/issues.src, import regexp/syntax instead of cmd/compile/internal/syntax
+ 2021-06-25 5160896c69 go/types: in TestStdlib, import from source instead of export data
+ 2021-06-25 d01bc571f7 runtime: make ncgocall a global counter

Change-Id: I1ce4a3b3ff7c824c67ad66dd27d9d5f1d25c0023