{ lib, stdenv, fetchurl, gettext, emacs }:

stdenv.mkDerivation rec {
  pname = "cflow";
  version = "1.7";

  src = fetchurl {
    url = "mirror://gnu/${pname}/${pname}-${version}.tar.bz2";
    sha256 = "sha256-0BFGyvkAHiZhM0F8KoJYpktfwW/LCCoU9lKCBNDJcIY=";
  };

  patchPhase = ''
    substituteInPlace "src/cflow.h"					\
      --replace "/usr/bin/cpp"						\
                "$(cat ${stdenv.cc}/nix-support/orig-cc)/bin/cpp"
  '';

  buildInputs = [ gettext ] ++
    # We don't have Emacs/GTK/etc. on {Dar,Cyg}win.
    lib.optional
      (! (lib.lists.any (x: stdenv.hostPlatform.system == x)
              [ "i686-cygwin" ]))
      emacs;

  doCheck = true;

  meta = with lib; {
    description = "Tool to analyze the control flow of C programs";
    mainProgram = "cflow";

    longDescription = ''
      GNU cflow analyzes a collection of C source files and prints a
      graph, charting control flow within the program.

      GNU cflow is able to produce both direct and inverted flowgraphs
      for C sources.  Optionally a cross-reference listing can be
      generated.  Two output formats are implemented: POSIX and GNU
      (extended).

      The package also provides Emacs major mode for examining the
      produced flowcharts in Emacs.
    '';

    license = licenses.gpl3Plus;

    homepage = "https://www.gnu.org/software/cflow/";

    maintainers = [ maintainers.vrthra ];

    platforms = platforms.linux ++ platforms.darwin;
  };
}