The previous code was way overcomplicating things. To find out if a
variable is a closure pseudo-variable, one only needs to check
IsClosureVar. Checking Captured and Byval are only meant to be used by
closure conversion.
Passes toolstash -cmp.
Change-Id: I22622cba36ba7f60b3275d17999a8b6bb7c6719a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280995
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
This CL moves the general deadcode-removal pass to before computing
Addrtaken, which allows variables to still be converted to SSA if
their address is only taken in unreachable code paths (e.g., the "&mp"
expression in the "if false" block in runtime/os_linux.go:newosproc).
This doesn't pass toolstash -cmp, because it allows SSA to better
optimize some code.
Change-Id: I43e54acc02fdcbad8eb6493283f355aa1ee0de84
Reviewed-on: https://go-review.googlesource.com/c/go/+/280992
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>
Matthew Dempsky [Fri, 1 Jan 2021 07:45:36 +0000 (23:45 -0800)]
[dev.regabi] cmd/compile: fix package-initialization order
This CL fixes package initialization order by creating the init task
before the general deadcode-removal pass.
It also changes noder to emit zero-initialization assignments (i.e.,
OAS with nil RHS) for package-block variables, so that initOrder can
tell the variables still need initialization. To allow this, we need
to also extend the static-init code to recognize zero-initialization
assignments.
This doesn't pass toolstash -cmp, because it reorders some package
initialization routines.
Fixes #43444.
Change-Id: I0da7996a62c85e15e97ce965298127e075390a7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/280976
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>
This commit splits up typecheck.Package and moves the code
elsewhere. The type-checking code is moved into noder, so that it can
eventually be interleaved with the noding process. The
non-type-checking code is moved back into package gc, so that it can
be incorporated into appropriate compiler backend phases.
While here, deadcode removal is moved into its own package.
Passes toolstash -cmp.
[git-generate]
cd src/cmd/compile/internal/typecheck
: Split into two functions.
sed -i -e '/Phase 6/i}\n\nfunc postTypecheck() {' typecheck.go
# Move into new package.
mv Deadcode deadcodeslice deadcodeexpr deadcode.go
mv deadcode.go cmd/compile/internal/deadcode
# Move top-level type-checking code into noder.
# Move DeclVars there too, now that nothing else uses it.
mv DeclVars Package noder.go
mv noder.go cmd/compile/internal/noder
# Move non-type-checking code back into gc.
mv postTypecheck main.go
mv main.go cmd/compile/internal/gc
'
Matthew Dempsky [Fri, 1 Jan 2021 05:32:52 +0000 (21:32 -0800)]
[dev.regabi] cmd/compile: report unused variables during typecheck
Unused variables are a type-checking error, so they should be reported
during typecheck rather than walk.
One catch is that we only want to report unused-variable errors for
functions that type check successfully, but some errors are reported
during noding, so we don't have an easy way to detect that
currently. As an approximate solution, we simply check if we've
reported any errors yet.
Passes toolstash -cmp.
Change-Id: I9400bfc94312c71d0c908a491e85c16d62224c9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/280973
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>
Matthew Dempsky [Thu, 31 Dec 2020 02:43:10 +0000 (18:43 -0800)]
[dev.regabi] cmd/compile: fix printing of method expressions
OTYPE and OMETHEXPR were missing from OpPrec. So add them with the
same precedences as OT{ARRAY,MAP,STRUCT,etc} and
ODOT{,METH,INTER,etc}, respectively. However, ODEREF (which is also
used for pointer types *T) has a lower precedence than other types, so
pointer types need to be specially handled to assign them their
correct, lower precedence.
Incidentally, this also improves the error messages in issue15055.go,
where we were adding unnecessary parentheses around the types in
conversion expressions.
Thanks to Cuong Manh Le for writing the test cases for #43428.
Fixes #43428.
Change-Id: I57e7979babe3ed9ef8a8b5a2a3745e3737dd785f
Reviewed-on: https://go-review.googlesource.com/c/go/+/280873
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>
The compiler has logic to check whether we implicitly dereferenced a
defined pointer while trying to select a method. However, rather than
checking whether there were any implicit dereferences of a defined
pointer, it was finding the innermost dereference/selector expression
and checking whether that was dereferencing a named pointer. Moreover,
it was only checking defined pointer declared in the package block.
This CL restructures the code to match go/types and gccgo's behavior.
Fixes #43384.
Change-Id: I7bddfe2515776d9480eb2c7286023d4c15423888
Reviewed-on: https://go-review.googlesource.com/c/go/+/280392
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Robert Griesemer <gri@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Matthew Dempsky [Wed, 30 Dec 2020 03:46:31 +0000 (19:46 -0800)]
[dev.regabi] cmd/compile: change ir.DoChildren to use bool result type
After using the IR visitor code for a bit, it seems clear that a
simple boolean result type is adequate for tree traversals. This CL
updates ir.DoChildren to use the same calling convention as ir.Any,
and updates mknode.go to generate code accordingly.
There were only two places where the error-based DoChildren API was
used within the compiler:
1. Within typechecking, marking statements that contain "break". This
code never returns errors anyway, so it's trivially updated to return
false instead.
2. Within inlining, the "hairy visitor" actually does make use of
returning errors. However, it threads through a reference to the
hairyVisitor anyway, where it would be trivial to store any needed
information instead. For the purpose of this CL, we provide
"errChildren" and "errList" helper functions that provide the previous
error-based semantics on top of the new bool-based API.
Passes toolstash -cmp.
Change-Id: I4bac9a697b4dbfb5f66eeac37d4a2ced2073d7d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/280675
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Matthew Dempsky [Tue, 29 Dec 2020 23:36:48 +0000 (15:36 -0800)]
[dev.regabi] cmd/compile: generalize ir/mknode.go
This CL generalizes ir/mknode.go to get rid of most of almost all of
its special cases for node field types. The only remaining speciale
case now is Field, which doesn't implement Node any more, but perhaps
should.
To help with removing special cases, node fields can now be tagged
with `mknode:"-"` so that mknode ignores them when generating its
helper methods. Further, to simplify skipping all of the orig fields,
a new origNode helper type is added which declares an orig field
marked as `mknode:"-"` and also provides the Orig and SetOrig methods
needed to implement the OrigNode interface.
Passes toolstash -cmp.
Change-Id: Ic68d4f0a9d2ef6e57e9fe87cdc641e5c4859830b
Reviewed-on: https://go-review.googlesource.com/c/go/+/280674
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>
Keith Randall [Sat, 28 Nov 2020 20:55:01 +0000 (12:55 -0800)]
[dev.regabi] cmd/compile: move new addrtaken bit back to the old name
Change-Id: I2732aefe95a21c23d73a907d5596fcb1626d6dd7
Reviewed-on: https://go-review.googlesource.com/c/go/+/275697
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
Keith Randall [Sat, 28 Nov 2020 20:37:55 +0000 (12:37 -0800)]
[dev.regabi] cmd/compile: remove original addrtaken bit
Switch the source of truth to the new addrtaken bit. Remove the old one.
Change-Id: Ie53679ab14cfcd34b55e912e7ecb962a22db7db3
Reviewed-on: https://go-review.googlesource.com/c/go/+/275696
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
Keith Randall [Sun, 29 Nov 2020 00:01:58 +0000 (16:01 -0800)]
[dev.regabi] cmd/compile: separate out address taken computation from typechecker
This CL computes a second parallel addrtaken bit that we check
against the old way of doing it. A subsequent CL will rip out the
typechecker code and just use the new way.
Change-Id: I62b7342c44f694144844695386f80088bbd40bf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/275695
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
1. Statements (including ODCLFUNC) don't have types, and the
Func.Nname already has a type. There's no need for a second one.
However, there is a lot of code that expects to be able to call
Func.Type, so leave a forwarding method, like with Sym and Linksym.
2. Inline and remove ir.NewFuncNameAt. It doesn't really save any
code, and it's only used a handful of places.
Passes toolstash -cmp.
Change-Id: I51acaa341897dae0fcdf2fa576a10174a2ae4d1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/280648
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>
Currently, the tcArith logic is complicated and involes many
un-necessary checks for some ir.Op. This CL refactors how it works:
- Add a new tcShiftOp function, which only does necessary works for
typechecking OLSH/ORSH. That ends up moving OLSH/ORSH to a separated
case in typecheck1.
- Move OASOP to separated case, so its logic is detached from tcArith.
- Move OANDAND/OOROR to separated case, which does some validation
dedicated to logical operators only.
Passes toolstash -cmp.
Change-Id: I0db7b7c7a3e52d6f9e9d87eee6967871f1c32200
Reviewed-on: https://go-review.googlesource.com/c/go/+/279442
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Matthew Dempsky [Tue, 29 Dec 2020 05:01:34 +0000 (21:01 -0800)]
[dev.regabi] cmd/compile: more Linksym cleanup
This largely gets rid of the remaining direct Linksym calls, hopefully
enough to discourage people from following bad existing practice until
Sym.Linksym can be removed entirely.
Passes toolstash -cmp.
Change-Id: I5d8f8f703ace7256538fc79648891ede0d879dc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/280641
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>
Matthew Dempsky [Tue, 29 Dec 2020 03:14:39 +0000 (19:14 -0800)]
[dev.regabi] cmd/compile: add Linksym helpers
Syms are meant to be just interned (pkg, name) tuples, and are a
purely abstract, Go-language concept. As such, associating them with
linker symbols (a low-level, implementation-oriented detail) is
inappropriate.
There's still work to be done before linker symbols can be directly
attached to their appropriate, higher-level objects instead. But in
the mean-time, we can at least add helper functions and discourage
folks from using Sym.Linksym directly. The next CL will mechanically
rewrite code to use these helpers where possible.
Passes toolstash -cmp.
Change-Id: I413bd1c80bce056304f9a7343526bd153f2b9c7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/280639
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>
Matthew Dempsky [Tue, 29 Dec 2020 01:30:04 +0000 (17:30 -0800)]
[dev.regabi] cmd/compile: move Node.Opt to Name
Escape analysis uses Node.Opt to map nodes to their "location", so
that other references to the same node use the same location
again. But in the current implementation of escape analysis, we never
need to refer back to a node's location except for named nodes (since
other nodes are anonymous, and have no way to be referenced).
This CL moves Opt from Node down to Name, turns it into a directly
accessed field, and cleans up escape analysis to avoid setting Opt on
non-named expressions.
One nit: in walkCheckPtrArithmetic, we were abusing Opt as a way to
detect/prevent loops. This CL adds a CheckPtr bit flag instead.
Passes toolstash -cmp.
Change-Id: If57d5ad8d972fa63bedbe69b9ebb6753e31aba85
Reviewed-on: https://go-review.googlesource.com/c/go/+/280638
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Matthew Dempsky [Tue, 29 Dec 2020 01:06:43 +0000 (17:06 -0800)]
[dev.regabi] cmd/compile: address some ir TODOs
Previously, ODOTTYPE/ODOTTYPE2 were forced to reuse some available
Node fields for storing pointers to runtime type descriptors. This
resulted in awkward field types for TypeAssertExpr and AddrExpr.
This CL gives TypeAssertExpr proper fields for the runtime type
descriptors, and also tightens the field types as
possible/appropriate.
Passes toolstash -cmp.
Change-Id: I521ee7a1462affc5459de33a0de6c68a7d6416ba
Reviewed-on: https://go-review.googlesource.com/c/go/+/280637
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>
These three expression nodes all represent the same syntax, and so
they're represented the same within types2. And also they're not
handled that meaningfully differently throughout the rest of the
compiler to merit unique representations.
Method expressions are somewhat unique today that they're very
frequently turned into plain function names. But eventually that can
be handled by a post-typecheck desugaring phase that reduces the
number of redundant AST forms.
Passes toolstash -cmp.
Change-Id: I20df91bbd0d885c1f18ec67feb61ae1558670719
Reviewed-on: https://go-review.googlesource.com/c/go/+/280636
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>
Matthew Dempsky [Mon, 28 Dec 2020 23:29:03 +0000 (15:29 -0800)]
[dev.regabi] cmd/compile: remove Sym.Importdef
Evidently it hasn't been needed since circa 2018, when we removed the
binary export data format.
Change-Id: I4e4c788d6b6233340fb0de0a56d035c31d96f761
Reviewed-on: https://go-review.googlesource.com/c/go/+/280634
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>
During recent refactoring, we moved mkbuiltin.go to package typecheck,
but accidentally duplicated its //go:generate directive into a bunch
of other files/directories. This CL cleans up the unnecessary
duplicates.
Also, update all of the stringer invocations to use an explicit file
name, and regenerate their files.
Updates #43369.
Change-Id: I4e493c1fff103d742de0a839d7a3375659270b50
Reviewed-on: https://go-review.googlesource.com/c/go/+/280635
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Meng Zhuo <mzh@golangcn.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Meng Zhuo <mzh@golangcn.org>
Matthew Dempsky [Mon, 28 Dec 2020 08:12:06 +0000 (00:12 -0800)]
[dev.regabi] all: merge master (1d78139) into dev.regabi
Merge List:
+ 2020-12-26 1d78139128 runtime/cgo: fix Android build with NDK 22
+ 2020-12-25 2018b68a65 net/mail: don't use MDT in test
+ 2020-12-23 b116404444 runtime: shift timeHistogram buckets and allow negative durations
+ 2020-12-23 8db7e2fecd runtime: fix allocs-by-size and frees-by-size buckets
+ 2020-12-23 fb96f07e1a runtime: fix nStackRoots comment about stack roots
+ 2020-12-23 d1502b3c72 lib/time, time/tzdata: update tzdata to 2020e
+ 2020-12-23 30c99cbb7a cmd/go: add the Retract field to 'go help mod edit' definition of the GoMod struct
+ 2020-12-23 49d0b239cb doc: fix a typo in contribute.html
+ 2020-12-23 98a73030b0 cmd/go: in 'go get', promote named implicit dependencies to explicit
+ 2020-12-23 fd6ba1c8a2 os/signal: fix a deadlock with syscall.AllThreadsSyscall() use
+ 2020-12-23 b0b0d98283 runtime: linux iscgo support for not blocking nptl signals
+ 2020-12-22 223331fc0c cmd/go/internal/modload: add hint for missing implicit dependency
Matthew Dempsky [Sun, 27 Dec 2020 19:26:12 +0000 (11:26 -0800)]
[dev.regabi] cmd/compile: check for recursive import in ImportBody
After earlier importer refactorings, most of the importer is now
reentrant, so we don't need to guard against it at Resolve. The only
remaining part that is still not reentrant is inline body importing,
so move the recursive-import check there.
Passes toolstash -cmp.
Change-Id: Ia828f880a03e6125b102668c12a155d4c253d26b
Reviewed-on: https://go-review.googlesource.com/c/go/+/280515
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>
Matthew Dempsky [Sun, 27 Dec 2020 19:11:11 +0000 (11:11 -0800)]
[dev.regabi] cmd/compile: remove Declare in makepartialcall
This is the only remaining late call to Declare. By changing it to use
Temp, we'll be able to move the legacy lexical scoping logic by moving
it to noder and iimport.
Passes toolstash -cmp.
Change-Id: Id7cf7a08e3138e50816f515fef3088785a10aaf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/280513
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>
This CL shuffles a couple functions around to help flatten the package
dependency graph somewhat:
1. ssa.LosesStmtMark is only ever used in associated with an
objw.Prog, so we might as well move it to that package. This removes a
dependency from objw (a relatively low-level utility package that
wraps cmd/internal/obj) on ssa (a large and relatively high-level
package).
2. Moves liveness.SetTypeBits into a new package typebits. A
single-function package is a bit on the silly side, but reflectdata
shouldn't need to depend on liveness (nor vice versa).
Matthew Dempsky [Sun, 27 Dec 2020 07:09:54 +0000 (23:09 -0800)]
[dev.regabi] cmd/compile: remove some unneeded code in package ir
The deepCopy functions haven't been needed since we switched to using
Edit everywhere, and AddStringExpr no longer has an Alloc field that
needs special casing.
Passes toolstash -cmp.
Change-Id: I5bcc8c73d5cb784f7e57fb3162ae6e288e6c9392
Reviewed-on: https://go-review.googlesource.com/c/go/+/280445
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>
Matthew Dempsky [Sun, 27 Dec 2020 07:03:25 +0000 (23:03 -0800)]
[dev.regabi] cmd/compile: remove CommStmt.List
Package syntax's parser already ensures that select communication
clauses only have one statement, so there's no need for ir's CommStmt
to need to represent more than one. Instead, noder can just directly
populate Comm in the first place.
Incidentally, this also revealed a latent issue in the inline-body
exporter: we were exporting List (where the case statement is before
type-checking), rather than Comm (where the case statement would be
after type-checking, when export happens).
Passes toolstash -cmp.
Change-Id: Ib4eb711527bed297c7332c79ed6e6562a1db2cfa
Reviewed-on: https://go-review.googlesource.com/c/go/+/280444
Trust: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Matthew Dempsky [Sun, 27 Dec 2020 06:42:17 +0000 (22:42 -0800)]
[dev.regabi] cmd/compile: separate CommStmt from CaseStmt
Like go/ast and cmd/compile/internal/syntax before it, package ir now
has separate concrete representations for switch-case clauses and
select-communication clauses.
Passes toolstash -cmp.
Change-Id: I32667cbae251fe7881be0f434388478433b2414f
Reviewed-on: https://go-review.googlesource.com/c/go/+/280443
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>
Meng Zhuo [Mon, 28 Dec 2020 07:22:47 +0000 (15:22 +0800)]
[dev.regabi] cmd/compile: add explicit file name in types generation
The stringer using `go list` for the type detection, which depends on
GOROOT. Unfortunally by changing GOROOT to develop path will raise
version mismatch with internal packages.
Update #43369
Change-Id: Id81334ea5f1ecdbfa81eb2d162944d65664ce727
Reviewed-on: https://go-review.googlesource.com/c/go/+/280572
Trust: Meng Zhuo <mzh@golangcn.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Matthew Dempsky [Sun, 27 Dec 2020 06:23:45 +0000 (22:23 -0800)]
[dev.regabi] cmd/compile: use []*CaseStmt in {Select,Switch}Stmt
Select and switch statements only ever contain case statements, so
change their Cases fields from Nodes to []*CaseStmt. This allows
removing a bunch of type assertions throughout the compiler.
CaseStmt should be renamed to CaseClause, and SelectStmt should
probably have its own CommClause type instead (like in go/ast and
cmd/compile/internal/syntax), but this is a good start.
Passes toolstash -cmp.
Change-Id: I2d41d616d44512c2be421e1e2ff13d0ee8b238ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/280442
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>
Matthew Dempsky [Sun, 27 Dec 2020 06:00:53 +0000 (22:00 -0800)]
[dev.regabi] cmd/compile: simplify some tree traversal code
When looking for referenced functions within bottomUpVisitor and
initDeps, the logic for ODOTMETH, OCALLPART, and OMETHEXPR are
basically identical, especially after previous refactorings to make
them use MethodExprName. This CL makes them exactly identical.
Passes toolstash -cmp.
Change-Id: I1f59c9be99aa9484d0397a0a6fb8ddd894a31c68
Reviewed-on: https://go-review.googlesource.com/c/go/+/280441
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>
Matthew Dempsky [Sun, 27 Dec 2020 05:43:30 +0000 (21:43 -0800)]
[dev.regabi] cmd/compile: simplify FuncName and PkgFuncName
Now that we have proper types, these functions can be restricted to
only allowing *ir.Func, rather than any ir.Node. And even more
fortunately, all of their callers already happen to always
pass *ir.Func arguments, making this CL pretty simple.
Passes toolstash -cmp.
Change-Id: I21ecd4c8cee3ccb8ba86b17cedb2e71c56ffe87a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280440
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>
After reorder3's simplification, the only remaining use of
refersToCommonName is in oaslit, where the LHS expression is always a
single name. We can replace the now overly-generalized
refersToCommonName with a simple ir.Any traversal with ir.Uses.
Passes toolstash -cmp.
Change-Id: Ice3020cdbbf6083d52e07866a687580f4eb134b8
Reviewed-on: https://go-review.googlesource.com/c/go/+/280439
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>
Matthew Dempsky [Sun, 27 Dec 2020 05:10:16 +0000 (21:10 -0800)]
[dev.regabi] cmd/compile: merge ascompatee, ascompatee1, and reorder3
These functions are interelated and have arbitrarily overlapping
responsibilities. By joining them together, we simplify the code and
remove some redundancy.
Passes toolstash -cmp.
Change-Id: I7c42cb7171b3006bc790199be3fd0991e6e985f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/280438
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>
Matthew Dempsky [Sun, 27 Dec 2020 03:55:57 +0000 (19:55 -0800)]
[dev.regabi] cmd/compile: simplify and optimize reorder3
reorder3 is the code responsible for ensuring that evaluation of an
N:N parallel assignment statement respects the order of evaluation
rules specified for Go.
This CL simplifies the code and improves it from an O(N^2) algorithm
to O(N).
Passes toolstash -cmp.
Change-Id: I04cd31613af6924f637b042be8ad039ec6a924c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/280437
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>
Matthew Dempsky [Sun, 27 Dec 2020 02:56:36 +0000 (18:56 -0800)]
[dev.regabi] cmd/compile: stop mangling SelectorExpr.Sel for ODOTMETH
ODOTMETH is unique among SelectorExpr expressions, in that Sel gets
mangled so that it no longer has the original identifier that was
selected (e.g., just "Foo"), but instead the qualified symbol name for
the selected method (e.g., "pkg.Type.Foo"). This is rarely useful, and
instead results in a lot of compiler code needing to worry about
undoing this change.
This CL changes ODOTMETH to leave the original symbol in place. The
handful of code locations where the mangled symbol name is actually
wanted are updated to use ir.MethodExprName(n).Sym() or (equivalently)
ir.MethodExprName(n).Func.Sym() instead.
Historically, the compiler backend has mistakenly used types.Syms
where it should have used ir.Name/ir.Funcs. And this change in
particular may risk breaking something, as the SelectorExpr.Sel will
no longer point at a symbol that uniquely identifies the called
method. However, I expect CL 280294 (desugar OCALLMETH into OCALLFUNC)
to have substantially reduced this risk, as ODOTMETH expressions are
now replaced entirely earlier in the compiler.
Passes toolstash -cmp.
Change-Id: If3c9c3b7df78ea969f135840574cf89e1d263876
Reviewed-on: https://go-review.googlesource.com/c/go/+/280436
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>
Matthew Dempsky [Sun, 27 Dec 2020 02:33:27 +0000 (18:33 -0800)]
[dev.regabi] cmd/compile: desugar OMETHEXPR into ONAME during walk
A subsequent CL will change FuncName to lazily create the ONAME nodes,
which isn't currently safe to do during SSA construction, because that
phase is concurrent.
Passes toolstash -cmp.
Change-Id: Ic24acc1d1160ad93b70ced3baa468f750e689ea6
Reviewed-on: https://go-review.googlesource.com/c/go/+/280435
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>
Matthew Dempsky [Sun, 27 Dec 2020 03:30:12 +0000 (19:30 -0800)]
[dev.regabi] cmd/compile: minor walkExpr cleanups
This CL cleans up a few minor points in walkExpr:
1. We don't actually care about computing the type-size of all
expressions that are walked. We care about computing the type-size of
all expressions that are *returned* by walk, as these are the
expressions that will actually be seen by the back end.
2. There's no need to call typecheck.EvalConst anymore. EvalConst used
to be responsible for doing additional constant folding during walk;
but for a while a now, it has done only as much constant folding as is
required during type checking (because doing further constant folding
led to too many issues with Go spec compliance). Instead, more
aggressive constant folding is handled entirely by SSA.
3. The code for detecting string constants and generating their
symbols can be simplified somewhat.
Passes toolstash -cmp.
Change-Id: I464ef5bceb8a97689c8f55435369a3402a5ebc55
Reviewed-on: https://go-review.googlesource.com/c/go/+/280434
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>
Matthew Dempsky [Sun, 27 Dec 2020 02:02:33 +0000 (18:02 -0800)]
[dev.regabi] cmd/compile: remove SelectorExpr.Offset field
Now that the previous CL ensures we always set SelectorExpr.Selection,
we can replace the SelectorExpr.Offset field with a helper method that
simply returns SelectorExpr.Selection.Offset.
Passes toolstash -cmp.
Change-Id: Id0f22b8b1980397b668f6860d27cb197b90ff52a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280433
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>
Matthew Dempsky [Sun, 27 Dec 2020 01:51:16 +0000 (17:51 -0800)]
[dev.regabi] cmd/compile: always use a Field for ODOTPTR expressions
During walk, we create ODOTPTR expressions to access runtime struct
fields. But rather than using an actual Field for the selection, we
were just directly setting the ODOTPTR's Offset field.
This CL changes walk to create proper struct fields (albeit without
the rest of their enclosing struct type) and use them for creating the
ODOTPTR expressions.
Passes toolstash -cmp.
Change-Id: I08dbac3ed29141587feb0905d15adbcbcc4ca49e
Reviewed-on: https://go-review.googlesource.com/c/go/+/280432
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>
Elias Naur [Fri, 25 Dec 2020 10:14:11 +0000 (11:14 +0100)]
runtime/cgo: fix Android build with NDK 22
Fixes #42655
Change-Id: I7d2b70098a4ba4dcb325fb0be076043789b86135
Reviewed-on: https://go-review.googlesource.com/c/go/+/280312
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Elias Naur <mail@eliasnaur.com>
Ian Lance Taylor [Wed, 23 Dec 2020 22:01:12 +0000 (14:01 -0800)]
net/mail: don't use MDT in test
When time.Parse sees a timezone name that matches the local timezone,
it uses the local timezone. The tests weren't expecting that,
so using MDT broke with TZ=America/Boise (where MDT means Mountain
Daylight Time). Just use GMT instead.
Fixes #43354
Change-Id: Ida70c8c867e2568b1535d1dfbf1fb0ed9e0e5c1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/280072
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
During walkCall, there's a half-hearted attempt at rewriting OCALLMETH
expressions into regular function calls by moving the receiver
argument into n.Args with the rest of the arguments. But the way it
does this leaves the AST in an inconsistent state (an ODOTMETH node
with no X expression), and leaves a lot of duplicate work for the rest
of the backend to deal with.
By simply rewriting OCALLMETH expressions into proper OCALLFUNC
expressions, we eliminate a ton of unnecessary code duplication during
SSA construction and avoid creation of invalid method-typed variables.
Passes toolstash -cmp.
Change-Id: I4d5c5f90a79f8994059b2d0ae472182e08096c0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280294
Trust: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Matthew Dempsky [Fri, 25 Dec 2020 08:12:15 +0000 (00:12 -0800)]
[dev.regabi] cmd/compile: don't emit reflect data for method types
Within the compiler, we represent the type of methods as a special
"method" type, where the receiver parameter type is kept separate from
the other parameters. This is convenient for operations like testing
whether a type implements an interface, where we want to ignore the
receiver type.
These method types don't properly exist within the Go language though:
there are only "function" types. E.g., method expressions (expressions
of the form Type.Method) are simply functions with the receiver
parameter prepended to the regular parameter list.
However, the compiler backend is currently a little sloppy in its
handling of these types, which results in temporary variables being
declared as having "method" type, which then end up in DWARF
data. This is probably harmless in practice, but it's still wrong.
The proper solution is to fix the backend code so that we use correct
types everywhere, and the next CL does exactly this. But as it fixes
the DWARF output, so it fails toolstash -cmp. So this prelim CL
bandages over the issue in a way that generates the same output as
that proper fix.
Change-Id: I37a127bc8365c3a79ce513bdb3cfccb945912762
Reviewed-on: https://go-review.googlesource.com/c/go/+/280293
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>
The assignment type-checking code previously bounced around a lot
between the LHS and RHS sides of the assignment. But there's actually
a very simple, consistent pattern to how to type check assignments:
1. Check the RHS expression.
2. If the LHS expression is an identifier that was declared in this
statement and it doesn't have an explicit type, give it the RHS
expression's default type.
3. Check the LHS expression.
4. Try assigning the RHS expression to the LHS expression, adding
implicit conversions as needed.
This CL implements this algorithm, and refactors tcAssign and
tcAssignList to use a common implementation. It also fixes the error
messages to consistently say just "1 variable" or "1 value", rather
than occasionally "1 variables" or "1 values".
Fixes #43348.
Passes toolstash -cmp.
Change-Id: I749cb8d6ccbc7d22cd7cb0a381f58a39fc2696b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/280112
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>
Matthew Dempsky [Thu, 24 Dec 2020 23:42:37 +0000 (15:42 -0800)]
[dev.regabi] cmd/compile: new devirtualization pkg [generated]
The devirtualization code was only in inl.go because it reused some of
the same helper functions as inlining (notably staticValue), but that
code all ended up in package ir instead anyway. Beyond that minor
commonality, it's entirely separate from inlining.
It's definitely on the small side, but consistent with the new
micropass-as-a-package approach we're trying.
Michael Anthony Knyszek [Tue, 22 Dec 2020 17:47:43 +0000 (17:47 +0000)]
runtime: shift timeHistogram buckets and allow negative durations
Today, timeHistogram, when copied, has the wrong set of counts for the
bucket that should represent (-inf, 0), when in fact it contains [0, 1).
In essence, the buckets are all shifted over by one from where they're
supposed to be.
But this also means that the existence of the overflow bucket is wrong:
the top bucket is supposed to extend to infinity, and what we're really
missing is an underflow bucket to represent the range (-inf, 0).
We could just always zero this bucket and continue ignoring negative
durations, but that likely isn't prudent.
timeHistogram is intended to be used with differences in nanotime, but
depending on how a platform is implemented (or due to a bug in that
platform) it's possible to get a negative duration without having done
anything wrong. We should just be resilient to that and be able to
detect it.
So this change removes the overflow bucket and replaces it with an
underflow bucket, and timeHistogram no longer panics when faced with a
negative duration.
Fixes #43328.
Fixes #43329.
Change-Id: If336425d7d080fd37bf071e18746800e22d38108
Reviewed-on: https://go-review.googlesource.com/c/go/+/279468
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
Michael Anthony Knyszek [Tue, 22 Dec 2020 16:23:29 +0000 (16:23 +0000)]
runtime: fix allocs-by-size and frees-by-size buckets
Currently these two metrics are reported incorrectly, going by the
documentation in the runtime/metrics package. We just copy in the
size-class-based values from the runtime wholesale, but those implicitly
have an inclusive upper-bound and exclusive lower-bound (e.g. 48-byte
size class contains objects in the size range (32, 48]) but the API
declares inclusive lower-bounds and exclusive upper-bounds.
Also, the bottom bucket representing (-inf, 1) should always be empty.
Extend the consistency check to verify this.
Updates #43329.
Change-Id: I11b5b062a34e13405ab662d15334bda91f779775
Reviewed-on: https://go-review.googlesource.com/c/go/+/279467
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
Change-Id: I709abe899ca498698463e945ccbcf4bc5fe60b92
Reviewed-on: https://go-review.googlesource.com/c/go/+/279794
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Andrey Bokhanko [Mon, 21 Dec 2020 16:33:55 +0000 (16:33 +0000)]
doc: fix a typo in contribute.html
A fix for a trivial (yet still confusing for neophytes like me!) typo in
contribute.html.
Change-Id: Ic68673fb2a3855c2b9e8042047087450e8793e6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/279452 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Cuong Manh Le [Wed, 23 Dec 2020 13:29:28 +0000 (20:29 +0700)]
[dev.regabi] cmd/compile: eliminate usage of ir.Node in liveness
All function parameters and return values in liveness have explicit
*ir.Name type, so use it directly instead of casting from ir.Node. While
at it, rename "affectedNode" to "affectedVar" to reflect this change.
Passes buildall w/ toolstash -cmp.
Change-Id: Id927e817a92ddb551a029064a2a54e020ca27074
Reviewed-on: https://go-review.googlesource.com/c/go/+/279434
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Jay Conrod [Wed, 16 Dec 2020 21:37:56 +0000 (16:37 -0500)]
cmd/go: in 'go get', promote named implicit dependencies to explicit
'go get pkg@vers' will now add an explicit requirement for the module
providing pkg if that version was already indirectly required.
'go get mod@vers' will do the same if mod is a module path but not a
package.
Requirements promoted this way will be marked "// indirect" because
'go get' doesn't know whether they're needed to build packages in the
main module. So users should prefer to run 'go get ./pkg' (where ./pkg
is a package in the main module) to promote requirements.
Fixes #43131
Change-Id: Ifbb65b71274b3cc752a7a593d6ddd875f7de23b8
Reviewed-on: https://go-review.googlesource.com/c/go/+/278812
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Matthew Dempsky [Wed, 23 Dec 2020 11:33:03 +0000 (03:33 -0800)]
[dev.regabi] cmd/compile: cleanup export code further
This CL rips off a number of toolstash bandages:
- Fixes position information for string concatenation.
- Adds position information for struct literal fields.
- Removes unnecessary exprsOrNil calls or replaces them with plain
expr calls when possible.
- Reorders conversion expressions to put type first, which matches
source order and also the order the importer needs for calling the
ConvExpr constructor.
Change-Id: I44cdc6035540d9ecefd9c1bcd92b8711d6ed813c
Reviewed-on: https://go-review.googlesource.com/c/go/+/279957
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>
After the previous CL, the only callers to NewFuncType, tointerface,
or NewStructType are the functions for type-checking the type literal
ASTs. So just inline the code there.
While here, refactor the Field type-checking logic a little bit, to
reduce some duplication.
Passes toolstash -cmp.
Change-Id: Ie12d14b87ef8b6e528ac9dccd609604bd09b98ec
Reviewed-on: https://go-review.googlesource.com/c/go/+/279956
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>
Matthew Dempsky [Wed, 23 Dec 2020 10:16:17 +0000 (02:16 -0800)]
[dev.regabi] cmd/compile: prefer types constructors over typecheck
Similar to the earlier mkbuiltin cleanup, there's a bunch of code that
calls typecheck.NewFuncType or typecheck.NewStructType, which can now
just call types.NewSignature and types.NewStruct, respectively.
Passes toolstash -cmp.
Change-Id: Ie6e09f1a7efef84b9a2bb5daa7087a6879979668
Reviewed-on: https://go-review.googlesource.com/c/go/+/279955
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>
Matthew Dempsky [Wed, 23 Dec 2020 08:50:18 +0000 (00:50 -0800)]
[dev.regabi] cmd/compile: update mkbuiltin.go to use new type constructors
We recently added new functions to types like NewSignature and
NewField, so we can use these directly rather than depending on the
typecheck and ir wrappers.
Passes toolstash -cmp.
Change-Id: I32676aa9a4ea71892216017756e72bcf90297219
Reviewed-on: https://go-review.googlesource.com/c/go/+/279953
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>
Russ Cox [Wed, 23 Dec 2020 06:07:07 +0000 (01:07 -0500)]
[dev.regabi] cmd/compile: split up walkexpr1, walkstmt [generated]
walkexpr1 is the second largest non-machine-generated function in the compiler.
weighing in at 1,164 lines. Since we are destroying the git blame history
anyway, now is a good time to split each different case into its own function,
making future work on this function more manageable.
Do the same to walkstmt too for consistency, even though it is a paltry 259 lines.