go/types: error diagnostics reported by go/types contain %!v(MISSING)

[myitcv]

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

$ go version
go version go1.20.4 linux/arm64
$ go list -m golang.org/x/tools
golang.org/x/tools v0.9.2-0.20230526183654-5974258e689a
$ go list -m golang.org/x/tools/gopls
golang.org/x/tools/gopls v0.0.0-20230526183654-5974258e689a

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="on"
GOARCH="arm64"
GOBIN=""
GOCACHE="/home/myitcv/.cache/go-build"
GOENV="/home/myitcv/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/myitcv/gostuff/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/myitcv/gostuff"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/myitcv/gos"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_arm64"
GOVCS=""
GOVERSION="go1.20.4"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/myitcv/gostuff/src/github.com/myitcv/playground/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 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1568132059=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Load the following file with a gopls-enabled editor:

package main

func main() {
	log("This is a test %v", 5)
}

func log(enabled bool, format string, args ...any) {
	log.Printf(format, args...)
}

What did you expect to see?

The following diagnostics (showing the vim-rendered version):

main.go|4 col 6| cannot use "This is a test %v" (untyped string constant) as bool value in argument to log
main.go|4 col 27| cannot use 5 (untyped int constant) as string value in argument to log
main.go|8 col 6| log.Printf undefined (type func(enabled bool, format string, args ...any) has no field or method Printf)

What did you see instead?

main.go|4 col 6| cannot use "This is a test %!v(MISSING)" (untyped string constant) as bool value in argument to log
main.go|4 col 27| cannot use 5 (untyped int constant) as string value in argument to log
main.go|8 col 6| log.Printf undefined (type func(enabled bool, format string, args ...any) has no field or method Printf)

Note the presence of %!v(MISSING) in the first line.

Log files:

• gopls.log
• govim.log

---

cc @findleyr

[findleyr]

Thank you for the report.

This is reproducible with go/types alone (simply copy the example above into src/go/types/testdata/manual.go.

We should not be passing user content as format strings, therefore this is a release blocker.

CC @griesemer

[griesemer]

Does not happen with types2. Fix forthcoming.

[gopherbot]

Change https://go.dev/cl/499275 mentions this issue: go/types: don't use user string as format string

[adonovan]

Perhaps the printf vet checker should be able to catch problems like this: a variable format string is passed to a printf wrapper, followed by no other arguments. I can't see how that would ever be useful.

See #60529.

[griesemer]

We have a type checker local printf test that perhaps can be adjusted. - gri

…

On Tue, May 30, 2023, 8:44 PM Alan Donovan ***@***.***> wrote: Perhaps the printf vet checker should be able to catch problems like this: a variable format string is passed to a printf wrapper, followed by no other arguments. I can't see how that would ever be useful. — Reply to this email directly, view it on GitHub <#60500 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACBCITZYRDXBAFIYORAIMQTXI25CXANCNFSM6AAAAAAYTUKIS4> . You are receiving this because you were assigned.Message ID: ***@***.***>