cmd/cgo: ${SRCDIR} doesn't properly handle paths with spaces

[jtsylve]

Given a cgo directive like the following

//#cgo CFLAGS: -I${SRCDIR}/../../include

I get the following error

malformed #cgo argument: -IC:/Users/Joe Sylve/go/src/go4n6/disk/vmdk/../../include

Neither of the following seem to make much of a difference

//#cgo CFLAGS: -I"${SRCDIR}/../../include"

//#cgo CFLAGS: -I\"${SRCDIR}/../../include\"

Tested on go1.5beta2 on both 32 and 64 bit Windows.

[alexbrainman]

Please, provide instructions to reproduce your issue. Thank you.

Alex

[mattn]

C:\>mkdir "foo bar"

C:\>cd "foo bar"

C:\foo bar>type con > main.go
package main

//#cgo CFLAGS: -I${SRCDIR}/../../include
import "C"

func main() {
}
^Z

C:\foo bar>go build
can't load package: package .: c:\foo bar\main.go: malformed
#cgo argument: -IC:/foo bar/../../include

[mattn]

This is depend on behavior of escape arguments on unix-shell or cmd.exe.

[alexbrainman]

Thank you @mattn. This is how it works on linux too:

# pwd
/root/src/issue 11868
# cat main.go
package main
//#cgo CFLAGS: -I${SRCDIR}/../../include
import "C"
func main() {
}
# go build
can't load package: package issue 11868: /root/src/issue 11868/main.go: malformed #cgo argument: -I/root/src/issue 11868/../../include
#

It appears we don't allow space inside of #cgo line parameters. I don't know why is that. Leaving for others to explain.

Alex

[ianlancetaylor]

It's a bug.

I don't know if changing safeCgoName in go/build/build.go is sufficient, or whether we need to add quoting somewhere.

[mattn]

gcc doesn't allows "-I/path/to directory". it should be -I"/path/to directory". (at least, on windows)

[jtsylve]

Have there been any more thoughts on how this can be fixed? If someone could point me in the right direction, I'd be happy to try to fix it myself.

[ianlancetaylor]

@jtsylve Thanks--I would start with my suggestion above: look at safeCgoName in go/build/build.go. Fix that to accept spaces. Then make sure any necessary quoting is done.

[rsc]

It is important that an attempted fix here does not allow spaces in other places. Changing safeCgoName sounds dangerous.

It does seem reasonable that ${SRCDIR}'s expansion should be properly handled even when that variable contains spaces.

[jtsylve]

The issue is more complicated than just changing safeCgoName, unfortunately. In order to make it work correctly with gcc we need to allow quotes. splitQuoted tends to affect this negatively. I have yet to come up with a reasonable solution.

[gopherbot]

CL https://golang.org/cl/16302 mentions this issue.

[jtsylve]

Under which cases is splitQuoted needed and when should we avoid spaces as @rsc mentioned?