X11/Xlib linker error


(^) #1

I’m trying to get Swift working with X11, and I keep getting this linker
error when I try to compile:

~/dev/cloudgen$ swift build -v
/usr/bin/lsb_release -r
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc --driver-mode=swift -I
/home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -L
/home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -lPackageDescription
/home/kelvin/dev/cloudgen/Package.swift -fileno 5
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swift-build-tool -f
/home/kelvin/dev/cloudgen/.build/debug.yaml -v
'/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc' -Xlinker
'-rpath=$ORIGIN' -g -L/home/kelvin/dev/cloudgen/.build/debug -o
/home/kelvin/dev/cloudgen/.build/debug/cloudgen '-lX11' -emit-executable
/home/kelvin/dev/cloudgen/.build/debug/cloudgen.build/main.swift.o
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:22: error: undefined
reference to 'XOpenDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:29: error: undefined
reference to 'XDefaultScreenOfDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:35: error: undefined
reference to 'XCreateSimpleWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:38: error: undefined
reference to 'XSelectInput'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:41: error: undefined
reference to 'XMapWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:47: error: undefined
reference to 'XNextEvent'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:52: error: undefined
reference to 'XFillRectangle'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:53: error: undefined
reference to 'XDrawString'
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
<unknown>:0: error: link command failed with exit code 1 (use -v to see
invocation)
<unknown>:0: error: build had 1 command failures

Here is the module.modulemap file I am using:

module X11 [system] {
  module Xlib {
    header "/usr/include/X11/Xlib.h"
  }
  module X {
    header "/usr/include/X11/X.h"
  }
  link "X11"
}

Why is it always this difficult to get something to show up on a screen in
Swift…


(Alex Blewitt) #2

If they are umbrella headers that include other header file dependencies, you may need an 'export *' in order to make them visible -- otherwise you only get the contents of that header file.

http://clang.llvm.org/docs/Modules.html#export-declaration

Alex

···

On 21 May 2017, at 20:48, Kelvin Ma via swift-users <swift-users@swift.org> wrote:

I’m trying to get Swift working with X11, and I keep getting this linker error when I try to compile:

~/dev/cloudgen$ swift build -v
/usr/bin/lsb_release -r
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc --driver-mode=swift -I /home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -L /home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -lPackageDescription /home/kelvin/dev/cloudgen/Package.swift -fileno 5
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swift-build-tool -f /home/kelvin/dev/cloudgen/.build/debug.yaml -v
'/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc' -Xlinker '-rpath=$ORIGIN' -g -L/home/kelvin/dev/cloudgen/.build/debug -o /home/kelvin/dev/cloudgen/.build/debug/cloudgen '-lX11' -emit-executable /home/kelvin/dev/cloudgen/.build/debug/cloudgen.build/main.swift.o
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:22: error: undefined reference to 'XOpenDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:29: error: undefined reference to 'XDefaultScreenOfDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:35: error: undefined reference to 'XCreateSimpleWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:38: error: undefined reference to 'XSelectInput'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:41: error: undefined reference to 'XMapWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:47: error: undefined reference to 'XNextEvent'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:52: error: undefined reference to 'XFillRectangle'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:53: error: undefined reference to 'XDrawString'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
<unknown>:0: error: link command failed with exit code 1 (use -v to see invocation)
<unknown>:0: error: build had 1 command failures

Here is the module.modulemap file I am using:

module X11 [system] {
  module Xlib {
    header "/usr/include/X11/Xlib.h"
  }
  module X {
    header "/usr/include/X11/X.h"
  }
  link "X11"
}


(^) #3

Tried that, doesn’t help

···

On Mon, May 22, 2017 at 4:23 AM, Alex Blewitt <alblue@apple.com> wrote:

On 21 May 2017, at 20:48, Kelvin Ma via swift-users <swift-users@swift.org> > wrote:

I’m trying to get Swift working with X11, and I keep getting this linker
error when I try to compile:

~/dev/cloudgen$ swift build -v
/usr/bin/lsb_release -r
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc --driver-mode=swift -I
/home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -L
/home/kelvin/devtools/swift-3.1-dev/usr/lib/swift/pm -lPackageDescription
/home/kelvin/dev/cloudgen/Package.swift -fileno 5
/home/kelvin/devtools/swift-3.1-dev/usr/bin/swift-build-tool -f
/home/kelvin/dev/cloudgen/.build/debug.yaml -v
'/home/kelvin/devtools/swift-3.1-dev/usr/bin/swiftc' -Xlinker
'-rpath=$ORIGIN' -g -L/home/kelvin/dev/cloudgen/.build/debug -o
/home/kelvin/dev/cloudgen/.build/debug/cloudgen '-lX11' -emit-executable
/home/kelvin/dev/cloudgen/.build/debug/cloudgen.build/main.swift.o
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:22: error:
undefined reference to 'XOpenDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:29: error:
undefined reference to 'XDefaultScreenOfDisplay'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:35: error:
undefined reference to 'XCreateSimpleWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:38: error:
undefined reference to 'XSelectInput'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:41: error:
undefined reference to 'XMapWindow'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:47: error:
undefined reference to 'XNextEvent'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:52: error:
undefined reference to 'XFillRectangle'
/home/kelvin/dev/cloudgen/Sources/cloudgen/main.swift:53: error:
undefined reference to 'XDrawString'
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
<unknown>:0: error: link command failed with exit code 1 (use -v to see
invocation)
<unknown>:0: error: build had 1 command failures

Here is the module.modulemap file I am using:

module X11 [system] {
  module Xlib {
    header "/usr/include/X11/Xlib.h"
  }
  module X {
    header "/usr/include/X11/X.h"
  }
  link "X11"
}

If they are umbrella headers that include other header file dependencies,
you may need an 'export *' in order to make them visible -- otherwise you
only get the contents of that header file.

http://clang.llvm.org/docs/Modules.html#export-declaration

Alex