cmd/cover: inconsistent NumStmt when //line clauses are used with Go 1.13.4 #35781
Description
This seems to be the same as #27350 but still happens even after running go fmt which was the recommended fix in that issue (and also in a release that includes d689946 which was intended to mitigate it).
Removing all //line comments from the file allows it to pass.
What version of Go are you using (go version)?
$ go version go version go1.13.4 linux/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/home/jesse/.cache/go-build" GOENV="/home/jesse/.config/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GONOPROXY="" GONOSUMDB="" GOOS="linux" GOPATH="/home/jesse/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/go" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64" GCCGO="gccgo" AR="ar" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="/home/jesse/go/src/github.com/timberio/go-datemath/go.mod" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build279863626=/tmp/go-build -gno-record-gcc-switches"
What did you do?
Using this repo, which uses goyacc to generate datemath.y.go, https://github.com/timberio/go-datemath
$ go test -coverprofile=c.out && go tool cover -html=c.out
PASS
coverage: 71.4% of statements
ok github.com/timberio/go-datemath 0.003s
cover: inconsistent NumStmt: changed from 2 to 1
I see the same issue using the example in the goyacc directory:
https://github.com/golang/tools/tree/master/cmd/goyacc/testdata/expr
When adding a dummy test file:
$ cat expr_test.go
package main
import "testing"
func TestFoo(t *testing.T) {
}
and then running:
$ go generate && go fmt && go test -coverprofile=c.out && go tool cover -html=c.out
PASS
coverage: 0.0% of statements
ok golang.org/x/tools/cmd/goyacc/testdata/expr 0.003s
cover: inconsistent NumStmt: changed from 1 to 2
What did you expect to see?
The coverage pulled up in the browser.
What did you see instead?
PASS
coverage: 71.4% of statements
ok github.com/timberio/go-datemath 0.006s
cover: inconsistent NumStmt: changed from 2 to 1