go1.10 build c-shared for to windows dll

[Baozisoftware]

Glad to see go1.10 support compiled dll, but the following questions (suggestions):

1. The export function has unnecessary entries;
2. The output file should be added ". dll" suffix;
3. Hope that you can specify the value of cgocheck at compile time instead of the runtime specified;
4. Hope to get rid of symbolic information against static analysis.

Here's the old version of the implementation:
disable cgocheck for golang default

go build to windows dll

Thank golang team for their hard work.

[ianlancetaylor]

I'm sorry, I'm not really sure what you mean by any of this. Can you be more specific? Is there any connection between the four things you mention?

CC @nadiasvertex

[Baozisoftware]

Sorry, my English is poor.

test.go

package main

import "C"

func main(){
}

//export Add
func Add(x,y int)int{
    return x+y
}

//export AddStr
func AddStr(x,y string)string{
    return x+y
}

Use the cmd to build(host:windows/amd64,go1.10b1):

set CGO_ENABLED=1
go build -ldflags="-s -w" -buildmode=c-shared test.go

Yes,i make it,but i have questions:

1. Output "test" file (no ".dll" suffix,here should be "test.dll");
2. Use dumpbin view export functions, I found a lot of goruntime functions export, hoping to hide them.
3. If cgocheck=1(default value),call "Add" funcation is normal,but call "AddStr" is crash,and At the moment can only be set before the call

GODEBUG=cgocheck=0

to solve, I hope we can compile this time instead of running to deal with this issue;

4. Use -ldflags=-s -w to build Seems to not be able to clear the symbolic information, you can still see a lot of goruntime symbols in IDA, although you can compile it with "strip" to manually clean it and hope it's built-in.

Thanks again.

[ianlancetaylor]

I think these problems will be easier to fix if you file separate issues for separate problems.

Regarding point 3, an exported Go function is not permitted to return a Go string. See https://tip.golang.org/cmd/cgo/#hdr-Passing_pointers .

[Baozisoftware]

Yes, these issues can be solved manually, but if the merger into the official code may have a better experience? I will modify the source code after the official version go1.10 released, thank you.

[shyandsy]

@Baozisoftware
I tried this command to build dll library

set CGO_ENABLED=1
go build -ldflags="-s -w" -buildmode=c-shared test.go

when I use this in the VC++ project, VS said "Warning LNK4003 invalid library format; library ignored"

any solution?

[ianlancetaylor]

@shyandsy This issue is closed. I recommend that you use a forum to ask your question. Please see https://golang.org/wiki/Questions .