Skip to content

cmd/compile: Cannot apply function from method expression #23917

Closed
@iporsut

Description

@iporsut

Please answer these questions before submitting your issue. Thanks!

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

  • go version go1.10 darwin/amd64

Does this issue reproduce with the latest release?

  • Yes.

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/username/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/username/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.10/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.10/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/9k/pvfwqqzn6fqbpwghhrcjkm480000gn/T/go-build409818854=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I try to appry method expression function from this code example

package main

import (
	"fmt"
	"io"
	"log"
	"os"
)

func main() {
	var b []byte = make([]byte, 100)

	v := struct{ io.Reader }{os.Stdin}
	f := struct{ io.Reader }.Read
	n, err := f(v, b)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(n)
}

What did you expect to see?

> go run temp.go 
0x1090c50
Hello
6

What did you see instead?

# command-line-arguments
go.struct { io.Reader }.Read·f: relocation target go.struct { io.Reader }.Read not defined
go.struct { io.Reader }.Read·f: undefined: "go.struct { io.Reader }.Read"

But when I add fmt.Println(f) like this

package main

import (
	"fmt"
	"io"
	"log"
	"os"
)

func main() {
	var b []byte = make([]byte, 100)

	v := struct{ io.Reader }{os.Stdin}
	f := struct{ io.Reader }.Read
	fmt.Println(f)
	n, err := f(v, b)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(n)
}

I can run with expected result.

Metadata

Metadata

Assignees

No one assigned

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions