Add cares build (#45)

WORKSPACE

@@ -107,3 +107,13 @@ new_http_archive(
         "https://github.com/ninja-build/ninja/archive/v1.8.2.tar.gz",
     ],
 )
+
+new_http_archive(
+    name = "cares",
+    build_file_content = all_content,
+    sha256 = "62dd12f0557918f89ad6f5b759f0bf4727174ae9979499f5452c02be38d9d3e8",
+    strip_prefix = "c-ares-cares-1_14_0",
+    urls = [
+        "https://github.com/c-ares/c-ares/archive/cares-1_14_0.tar.gz",
+    ],
+)

examples/cmake_cares/BUILD

@@ -0,0 +1,23 @@
+load("//tools/build_defs:cmake.bzl", "cmake_external")
+load("//tools/build_defs:ninja_build.bzl", "ninja_tool")
+
+ninja_tool(
+    name = "ninjatool",
+    ninja_srcs = "@ninja_build//:all",
+)
+
+sh_library(
+    name = "ninja",
+    srcs = [":ninjatool"],
+)
+
+cmake_external(
+    name = "cares",
+    cache_entries = {
+        "CARES_SHARED": "no",
+        "CARES_STATIC": "on",
+    },
+    lib_source = "@cares//:all",
+    static_libraries = ["libcares.a"],
+    tools_deps = [":ninjatool"],
+)