spec: package initialization issue #25474
Description
The following piece of code produces different result from SPEC
$ cat main.go
package main
import "fmt"
var (
a = c + b
b = f()
c = f()
d = 3
)
func f() int {
d++
return d
}
func main() {
fmt.Println(a, b, c, d)
}
$ go run main.go
9 5 4 5Following the SPEC, b should be initialized before c, so instead of 9 5 4 5, 9 4 5 5 is expected, according to the SPEC:
... package-level variables are initialized in declaration order but after any of the variables they depend on.
However, if we change a = c + b to a = b + c, then b is initialized before c.
So it seems like the order of presence precedes the order of declaration, deviating the SPEC.
go version: 1.10.2 darwin/amd64
go env:
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/user/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/user/go"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.10.2/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.10.2/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/d3/8sk_rdjx1s703xh89gb4x38h0000gn/T/go-build710804438=/tmp/go-build -gno-record-gcc-switches -fno-common"