cmd/compile: internal compiler error: expression has untyped type

[johejo]

What version of Go are you using (go version)?

$ go version
go version devel go1.20-ee833ed72e Fri Aug 19 01:34:22 2022 +0000 darwin/arm64

Does this issue reproduce with the latest release?

tip only

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="arm64"
GOBIN=""
GOCACHE="/Users/mitsuoheijo/Library/Caches/go-build"
GOENV="/Users/mitsuoheijo/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/mitsuoheijo/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/mitsuoheijo/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/Users/mitsuoheijo/ghq/github.com/golang/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/Users/mitsuoheijo/ghq/github.com/golang/go/pkg/tool/darwin_arm64"
GOVCS=""
GOVERSION="devel go1.20-ee833ed72e Fri Aug 19 01:34:22 2022 +0000"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/mitsuoheijo/ghq/github.com/golang/go/src/go.mod"
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/bq/s3vkkxm17jq79lx5qy3856zh0000gn/T/go-build1579252278=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Build hashicorp/nomad

git clone https://github.com/hashicorp/nomad
cd nomad
gotip build ./...

Trying to find minimal reproduction.

What did you expect to see?

Build successful

What did you see instead?

# github.com/hashicorp/nomad/nomad/structs/config
nomad/structs/config/consul.go:153:36: internal compiler error: expression has untyped type:
.   ANDAND untyped bool tc(1) # consul.go:153:36
.   .   ANDAND untyped bool tc(1) # consul.go:153:36
.   .   .   EQ untyped bool tc(1) # consul.go:153:36
.   .   .   .   LEN int tc(1) # consul.go:153:36
.   .   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   LITERAL-5 int tc(1) # consul.go:153:36
.   .   .   EQ untyped bool tc(1) # consul.go:153:36
.   .   .   .   LITERAL-1886680168 uint32 tc(1) # consul.go:153:36
.   .   .   .   OR uint32 tc(1) # consul.go:153:36
.   .   .   .   .   OR uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   OR uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   CONV uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   INDEX byte tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   .   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   .   .   .   .   .   LITERAL-0 int tc(1) # consul.go:153:36
.   .   .   .   .   .   .   LSH uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   CONV uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   .   INDEX byte tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   .   .   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   .   .   .   .   .   .   LITERAL-1 int tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   LITERAL-8 uint tc(1) # consul.go:153:36
.   .   .   .   .   .   LSH uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   CONV uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   INDEX byte tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   .   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   .   .   .   .   .   LITERAL-2 int tc(1) # consul.go:153:36
.   .   .   .   .   .   .   LITERAL-16 uint tc(1) # consul.go:153:36
.   .   .   .   .   LSH uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   CONV uint32 tc(1) # consul.go:153:36
.   .   .   .   .   .   .   INDEX byte tc(1) # consul.go:153:36
.   .   .   .   .   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   .   .   .   .   LITERAL-3 int tc(1) # consul.go:153:36
.   .   .   .   .   .   LITERAL-24 uint tc(1) # consul.go:153:36
.   .   EQ untyped bool tc(1) # consul.go:153:36
.   .   .   INDEX byte tc(1) # consul.go:153:36
.   .   .   .   DOTPTR config.Scheme string tc(1) # consul.go:153:28
.   .   .   .   .   NAME-config.def esc(no) Class:PAUTO Offset:0 OnStack Used PTR-*api.Config tc(1) # consul.go:136:2
.   .   .   .   LITERAL-4 int tc(1) # consul.go:153:36
.   .   .   LITERAL-115 byte tc(1) # consul.go:153:36

goroutine 1 [running]:
runtime/debug.Stack()
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/runtime/debug/stack.go:24 +0x64
cmd/compile/internal/base.FatalfAt({0x5768738?, 0x1?}, {0x10552e41f, 0x20}, {0x14000aac8b8, 0x1, 0x1})
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/base/print.go:227 +0x224
cmd/compile/internal/base.Fatalf(...)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/walk.walkExpr({0x105768738, 0x140003d73e0}, 0x14000dbb530)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:53 +0x358
cmd/compile/internal/walk.finishCompare(0x14000502e00, {0x105768738?, 0x140003d73e0?}, 0x104efc158?)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/compare.go:457 +0x4c
cmd/compile/internal/walk.walkCompareString(0x14000502e00, 0x14000aad530)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/compare.go:422 +0x1000
cmd/compile/internal/walk.walkCompare(0x14000502e00, 0x14000aad530)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/compare.go:48 +0xfa4
cmd/compile/internal/walk.walkExpr1({0x105767488, 0x14000502e00}, 0x14000502e00?)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:156 +0x6f8
cmd/compile/internal/walk.walkExpr({0x105767488, 0x14000502e00}, 0x14000aad530)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:56 +0x368
cmd/compile/internal/walk.walkAssign(0x14000dbb530, {0x105767318?, 0x140005b1c20?})
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/assign.go:72 +0x944
cmd/compile/internal/walk.walkExpr1({0x105767318, 0x140005b1c20}, 0x140005b1c20?)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:180 +0x3c8
cmd/compile/internal/walk.walkExpr({0x105767318, 0x140005b1c20}, 0x14000aad530)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:56 +0x368
cmd/compile/internal/walk.appendWalkStmt(0x14000dbb530, {0x105767318, 0x140005b1c20})
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/walk.go:256 +0x64
cmd/compile/internal/walk.ascompatee(0x15, {0x14000899000?, 0x2, 0x1?}, {0x14000899040?, 0x2, 0x1?})
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/assign.go:375 +0x494
cmd/compile/internal/walk.walkAssignList(0x14000aad8d0, 0x14000827680)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/assign.go:147 +0x128
cmd/compile/internal/walk.walkExpr1({0x1057671a8, 0x14000827680}, 0x14000827680?)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:184 +0x2cc
cmd/compile/internal/walk.walkExpr({0x1057671a8, 0x14000827680}, 0x14000aad8d0)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/expr.go:56 +0x368
cmd/compile/internal/walk.walkStmt({0x1057671a8, 0x14000827680?})
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/stmt.go:58 +0x74c
cmd/compile/internal/walk.walkStmtList(...)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/stmt.go:177
cmd/compile/internal/walk.Walk(0x140009583c0)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/walk/walk.go:43 +0x194
cmd/compile/internal/gc.prepareFunc(0x140009583c0)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/gc/compile.go:92 +0x80
cmd/compile/internal/gc.enqueueFunc(0x140009583c0)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/gc/compile.go:66 +0x29c
cmd/compile/internal/gc.Main(0x10575cc60)
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/internal/gc/main.go:295 +0x1174
main.main()
        /Users/mitsuoheijo/ghq/github.com/golang/go/src/cmd/compile/main.go:57 +0xf4

[johejo]

Build passed when GOEXPERIMENT=nounified

[seankhliao]

cc @mdempsky

[cuonglm]

Minimal reproducer:

package p

func G[T any](t T) *T {
	return &t
}

func f(x string) {
	_ = G(x == "foo")
}

[mdempsky]

In the -l -W=2 output for @cuonglm's minimized test case, I see:

before walk f
.   AS tc(1) # w.go:8:4
.   .   NAME-p._ Offset:0 blank tc(1)
.   .   CALLFUNC PTR-*go.shape.bool tc(1) # w.go:8:7
.   .   .   NAME-p.G[go.shape.bool] Class:PFUNC Offset:0 Used FUNC-func(*[2]uintptr, go.shape.bool) *go.shape.bool tc(1) # w.go:3:6
.   .   CALLFUNC-Args
.   .   .   ADDR PTR-*[2]uintptr tc(1) # w.go:8:6
.   .   .   .   NAME-p..dict.G[bool] Class:PEXTERN Offset:0 Addrtaken Used ARRAY-[2]uintptr tc(1) # <autogenerated>:1:0
.   .   .   EQ go.shape.bool tc(1) # w.go:8:10
.   .   .   .   NAME-p.x esc(no) Class:PPARAM Offset:0 OnStack Used string tc(1) # w.go:7:8
.   .   .   .   LITERAL-"foo" string tc(1) # w.go:8:13

That looks right to me.

I think the issue is that walk is desugaring the OEQ expression into an "untyped bool" expression; and then somewhere we decide whether to convert it to the original type (go.shape.bool), but types.Identical reports them as identical so we skip coercing back to go.shape.bool.

Probably the fix is to ensure the conversion from "untyped bool" to "go.shape.bool" really happens as needed.

[mdempsky]

I think the issue is the typecheck.Conv call in walk.finishCompare.

Probably we want to change the types.Identical calls to types.IdenticalStrict.

[cuonglm]

I think the issue is the typecheck.Conv call in walk.finishCompare.

Probably we want to change the types.Identical calls to types.IdenticalStrict.

Yeah, for nounified, at that stage, n.Type() is bool, not go.shape.bool like unified. I wonder we can make unified IR behaves the same 🤔

[mdempsky]

The issue affects nounified too: https://go.dev/play/p/BKYr_UUMGvH

[gopherbot]

Change https://go.dev/cl/424936 mentions this issue: cmd/compile: fix unified IR regressions

[gopherbot]

Change https://go.dev/cl/424937 mentions this issue: cmd/compile: fix "expression has untyped type" ICE in generic code