libdill 2.3 (new formula)

Closes #24134.

Signed-off-by: FX Coudert <fxcoudert@gmail.com>

Formula/libdill.rb

@@ -0,0 +1,43 @@
+class Libdill < Formula
+  desc "Structured concurrency in C"
+  homepage "http://libdill.org/"
+  url "https://github.com/sustrik/libdill/archive/2.3.tar.gz"
+  sha256 "f83cba87b1b0d1a8ad0f6345c448c14dee685ee733f3c3ee93f2321acc1bd083"
+
+  depends_on "autoconf" => :build
+  depends_on "automake" => :build
+  depends_on "libtool" => :build
+
+  def install
+    system "./autogen.sh"
+    system "./configure", "--disable-debug",
+                          "--disable-dependency-tracking",
+                          "--disable-silent-rules",
+                          "--prefix=#{prefix}"
+    system "make", "install"
+  end
+
+  test do
+    (testpath/"test.c").write <<~EOS
+      #include <libdill.h>
+      #include <stdio.h>
+      #include <stdlib.h>
+
+      coroutine void worker(const char *text) {
+          while(1) {
+              printf("%s\\n", text);
+              msleep(now() + random() % 500);
+          }
+      }
+
+      int main() {
+          go(worker("Hello!"));
+          go(worker("World!"));
+          msleep(now() + 5000);
+          return 0;
+      }
+    EOS
+    system ENV.cc, "-I#{include}", "-L#{lib}", "-ldill", "-o", "test", "test.c"
+    system "./test"
+  end
+end