cmd/go: test -coverprofile with swig fails

[jackielii]

Go version

go version go1.21.2 darwin/arm64

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

GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/jackieli/Library/Caches/go-build'
GOENV='/Users/jackieli/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/jackieli/go/pkg/mod'
GONOPROXY='tespkg.in,github.com/tespkg,gitlab.com/target-digital-transformation'
GONOSUMDB='tespkg.in,github.com/tespkg,gitlab.com/target-digital-transformation'
GOOS='darwin'
GOPATH='/Users/jackieli/go'
GOPRIVATE='tespkg.in,github.com/tespkg,gitlab.com/target-digital-transformation'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/opt/homebrew/Cellar/go/1.21.2/libexec'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/homebrew/Cellar/go/1.21.2/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.21.2'
GCCGO='gccgo'
AR='ar'
CC='cc'
CXX='c++'
CGO_ENABLED='1'
GOMOD='/Users/jackieli/Downloads/simple/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build3418952473=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

Use a simple project with a swig file in it: simple-test.zip

Run go test works
Run go test -coverprofile .testCoverage.txt fails with message:

go build simple:
# cover simple
2023/12/11 22:43:50 cover: open $WORK/b102//var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build368947532/b102/_main_swig.cover.go: no such file or directory
FAIL	simple [build failed]

What did you expect to see?

go test -coverprofile works

What did you see instead?

go test -coverprofile .testCoverage.txt fails with message:

go build simple:
# cover simple
2023/12/11 22:43:50 cover: open $WORK/b102//var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build368947532/b102/_main_swig.cover.go: no such file or directory
FAIL	simple [build failed]

Additionally the output when with go test -x -coverprofile .testCoverage.txt

go test -x -coverprofile .testCoverage.txt

  WORK=/var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849
  mkdir -p $WORK/b001/
  mkdir -p $WORK/b020/
  mkdir -p $WORK/b013/
  mkdir -p $WORK/b016/
  mkdir -p $WORK/b014/
  mkdir -p $WORK/b009/
  mkdir -p $WORK/b007/
  mkdir -p $WORK/b035/
  mkdir -p $WORK/b025/
  mkdir -p $WORK/b037/
  mkdir -p $WORK/b015/
  mkdir -p $WORK/b041/
  mkdir -p $WORK/b018/
  mkdir -p $WORK/b045/
  mkdir -p $WORK/b019/
  mkdir -p $WORK/b071/
  mkdir -p $WORK/b089/
  mkdir -p $WORK/b090/
  mkdir -p $WORK/b096/
  mkdir -p $WORK/b027/
  mkdir -p $WORK/b012/
  mkdir -p $WORK/b006/
  mkdir -p $WORK/b017/
  mkdir -p $WORK/b011/
  mkdir -p $WORK/b039/
  mkdir -p $WORK/b010/
  mkdir -p $WORK/b005/
  mkdir -p $WORK/b026/
  mkdir -p $WORK/b032/
  mkdir -p $WORK/b004/
  mkdir -p $WORK/b049/
  mkdir -p $WORK/b036/
  mkdir -p $WORK/b052/
  mkdir -p $WORK/b024/
  mkdir -p $WORK/b030/
  mkdir -p $WORK/b034/
  mkdir -p $WORK/b051/
  mkdir -p $WORK/b028/
  mkdir -p $WORK/b062/
  mkdir -p $WORK/b086/
  mkdir -p $WORK/b043/
  mkdir -p $WORK/b050/
  mkdir -p $WORK/b040/
  mkdir -p $WORK/b048/
  mkdir -p $WORK/b061/
  mkdir -p $WORK/b058/
  mkdir -p $WORK/b038/
  mkdir -p $WORK/b081/
  mkdir -p $WORK/b047/
  mkdir -p $WORK/b023/
  mkdir -p $WORK/b067/
  mkdir -p $WORK/b080/
  mkdir -p $WORK/b031/
  mkdir -p $WORK/b070/
  mkdir -p $WORK/b088/
  mkdir -p $WORK/b029/
  mkdir -p $WORK/b022/
  mkdir -p $WORK/b056/
  mkdir -p $WORK/b033/
  mkdir -p $WORK/b021/
  mkdir -p $WORK/b003/
  mkdir -p $WORK/b053/
  mkdir -p $WORK/b046/
  mkdir -p $WORK/b044/
  mkdir -p $WORK/b055/
  mkdir -p $WORK/b054/
  mkdir -p $WORK/b094/
  mkdir -p $WORK/b092/
  mkdir -p $WORK/b099/
  mkdir -p $WORK/b069/
  mkdir -p $WORK/b095/
  mkdir -p $WORK/b091/
  mkdir -p $WORK/b101/
  mkdir -p $WORK/b093/
  mkdir -p $WORK/b042/
  mkdir -p $WORK/b097/
  mkdir -p $WORK/b098/
  mkdir -p $WORK/b100/
  mkdir -p $WORK/b087/
  mkdir -p $WORK/b103/
  cp /Users/jackieli/Library/Caches/go-build/9b/9b2bb0e3ac1b16efdbc8ca5a95d2ae084340b1f9d5e8300071e4d4f18e9a6227-d $WORK/b103/_cgo_gotypes.go
  cp /Users/jackieli/Library/Caches/go-build/ab/ab115b8041115aec8fccc5362216233eb3640d462533a86dbf27e17740c7cefc-d $WORK/b103/cgo.cgo1.go
  cp /Users/jackieli/Library/Caches/go-build/e7/e7322c53a39b536e027f8264f29ab9c8263c129048e4fd7c0381c646e5998571-d $WORK/b103/_cgo_import.go
  mkdir -p $WORK/b102/
  cd .
  swig -version
  cd /Users/jackieli/Downloads/simple
  /opt/homebrew/Cellar/go/1.21.2/libexec/pkg/tool/darwin_arm64/compile -o $WORK/b102/_go_.o -trimpath "$WORK/b102=>" -p main -complete -goversion go1.21.2 -c=4 -shared -nolocalimports $WORK/swig_intsize.go
  swig -go -cgo -intgosize 64 -module main -o $WORK/b102/main_wrap.c -outdir $WORK/b102/ main.swig
  mv $WORK/b102/main.go $WORK/b102/_main_swig.go
  cat >/var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/pkgcfg.txt << 'EOF' # internal
  {"OutConfig":"/var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/coveragecfg","PkgPath":"simple","PkgName":"main","Granularity":"perblock","ModulePath":"simple","Local":false}EOF
  cat >/var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/coveroutfiles.txt << 'EOF' # internal
  /var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/covervars.go
  /var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/main.cover.go
  /var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102//var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/_main_swig.cover.go
  EOF
  cd $WORK/b102/
  /opt/homebrew/Cellar/go/1.21.2/libexec/pkg/tool/darwin_arm64/cover -pkgcfg ./pkgcfg.txt -mode set -var goCover_a7a39b72f297_ -outfilelist ./coveroutfiles.txt /Users/jackieli/Downloads/simple/main.go /Users/jackieli/Downloads/simple$WORK/b102/_main_swig.go
  go build simple:
  # cover simple
  2023/12/11 22:45:14 cover: open $WORK/b102//var/folders/v7/nkqv5k_906s7gq6l4h30kq_w0000gn/T/go-build821224849/b102/_main_swig.cover.go: no such file or directory
  rm -r $WORK/b001/
  FAIL    simple [build failed]

Also note that last version I used for this project go1.18 works. I also tested go1.21 on Linux/amd64, same error.

/cc @ianlancetaylor

[prattmic]

cc @thanm

[thanm]

Thanks for the report. I'll take a look.

[thanm]

I spent a little time looking at this. When using Go 1.19 or with Go 1.20 plus the "new coverage experiment" disabled (GOEXPERIMENT=nocoverageredesign), the swig-generated source file (_main_swig.go) is never actually passed to the cover tool. This is due to the fact that only those files processed by DeclareCoverVars will be instrumented. The new coverage implementation gets rid of DeclareCoverVars, and as a result what happens is that _main_swig.go gets added to the package list of cgo files here and then processed along with everything else. This should be relatively straightforward to fix -- just run the cover tool on the original list of go and cgo files.

[gopherbot]

Change https://go.dev/cl/552095 mentions this issue: cmd/go: run cover tool before swig