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Commit Graph

7 Commits

Author SHA1 Message Date
Cuong Manh Le
ddc93a536f cmd/compile: fix unified IR shapifying recursive instantiated types
Shape-based stenciling in unified IR is done by converting type argument
to its underlying type. So it agressively check that type argument is
not a TFORW. However, for recursive instantiated type argument, it may
still be a TFORW when shapifying happens. Thus the assertion failed,
causing the compiler crashing.

To fix it, just allow fully instantiated type when shapifying.

Fixes #54512
Fixes #54722

Change-Id: I527e3fd696388c8a37454e738f0324f0c2ec16cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/426335
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-08-30 17:23:27 +00:00
Matthew Dempsky
503de697cb Revert "cmd/compile: restore test/nested.go test cases"
This reverts CL 424854.

Reason for revert: broke misc/cgo/stdio.TestTestRun on several builders.

Will re-land after CL 421879 is submitted.

Change-Id: I2548c70d33d7c178cc71c1d491cd81c22660348f
Reviewed-on: https://go-review.googlesource.com/c/go/+/425214
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
2022-08-23 19:37:34 +00:00
Matthew Dempsky
72a76ca1f9 cmd/compile: restore test/nested.go test cases
When handling a type declaration like:

```
type B A
```

unified IR has been writing out that B's underlying type is A, rather
than the underlying type of A.

This is a bit awkward to implement and adds complexity to importers,
who need to handle resolving the underlying type themselves. But it
was necessary to handle when A was declared like:

```
//go:notinheap
type A int
```

Because we expected A's not-in-heap'ness to be conferred to B, which
required knowing that A was on the path from B to its actual
underlying type int.

However, since #46731 was accepted, we no longer need to support this
case. Instead we can write out B's actual underlying type.

One stumbling point though is the existing code for exporting
interfaces doesn't work for the underlying type of `comparable`, which
is now needed to implement `type C comparable`. As a bit of a hack, we
we instead export its underlying type as `interface{ comparable }`.

Fixes #54512.

Change-Id: I0fb892068d656f1e87bb8ef97da27756051126d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/424854
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2022-08-23 18:13:38 +00:00
Matthew Dempsky
38edd9bd8d cmd/compile/internal/noder: shape-based stenciling for unified IR
This CL switches unified IR to use shape-based stenciling with runtime
dictionaries, like the existing non-unified frontend. Specifically,
when instantiating generic functions and types `X[T]`, we now also
instantiated shaped variants `X[shapify(T)]` that can be shared by
`T`'s with common underlying types.

For example, for generic function `F`, `F[int](args...)` will be
rewritten to `F[go.shape.int](&.dict.F[int], args...)`.

For generic type `T` with method `M` and value `t` of type `T[int]`,
`t.M(args...)` will be rewritten to `T[go.shape.int].M(t,
&.dict.T[int], args...)`.

Two notable distinctions from the non-unified frontend:

1. For simplicity, currently shaping is limited to simply converting
type arguments to their underlying type. Subsequent CLs will implement
more aggressive shaping.

2. For generic types, a single dictionary is generated to be shared by
all methods, rather than separate dictionaries for each method. I
originally went with this design because I have an idea of changing
interface calls to pass the itab pointer via the closure
register (which should have zero overhead), and then the interface
wrappers for generic methods could use the *runtime.itab to find the
runtime dictionary that corresponds to the dynamic type. This would
allow emitting fewer method wrappers.

However, this choice does have the consequence that currently even if
a method is unused and its code is pruned by the linker, it may have
produced runtime dictionary entries that need to be kept alive anyway.

I'm open to changing this to generate per-method dictionaries, though
this would require changing the unified IR export data format; so it
would be best to make this decision before Go 1.20.

The other option is making the linker smarter about pruning unneeded
dictionary entries, like how it already prunes itab entries. For
example, the runtime dictionary for `T[int]` could have a `R_DICTTYPE`
meta-relocation against symbol `.dicttype.T[go.shape.int]` that
declares it's a dictionary associated with that type; and then each
method on `T[go.shape.T]` could have `R_DICTUSE` meta-relocations
against `.dicttype.T[go.shape.T]+offset` indicating which fields
within dictionaries of that type need to be preserved.

Change-Id: I369580b1d93d19640a4b5ecada4f6231adcce3fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/421821
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-18 13:16:21 +00:00
Matthew Dempsky
e24977d231 all: avoid use of cmd/compile -G flag in tests
The next CL will remove the -G flag, effectively hard-coding it to its
current default (-G=3).

Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831
Reviewed-on: https://go-review.googlesource.com/c/go/+/388534
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-01 19:45:34 +00:00
Matthew Dempsky
49ade6b298 [dev.typeparams] test: add expected failure mechanism
This CL changes the existing excluded-test mechanism into a
known-failure mechanism instead. That is, it runs the test regardless,
but only reports if it failed (or succeeded) unexpectedly.

It also splits the known failures list into fine-grain failure lists
for types2, types2 w/ 32-bit target, -G=3, and unified.

Updates #46704.

Change-Id: I1213cbccf1bab6a92d9bfcf0d971a2554249bbff
Reviewed-on: https://go-review.googlesource.com/c/go/+/332551
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2021-07-07 11:12:13 +00:00
Matthew Dempsky
1ba2074440 [dev.typeparams] cmd/compile/internal/types2: support local defined types
This CL changes types2's instance hashing logic to include position
information for function-scope defined types as disambiguation. This
isn't ideal, but it worked for getting nested.go passing.

Updates #46592.

Change-Id: Id83ba0001f44af69b81260306cc8b05e44fc4f09
Reviewed-on: https://go-review.googlesource.com/c/go/+/327170
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
2021-06-16 21:38:50 +00:00