Modify hello world example with CMake to build on Windows (#86)

- with MSBuild generator (the path to it should be on the PATH)
- use CMake crosstool file

examples/BUILD

@@ -1,12 +1,21 @@
+tests = [
+    "//examples/cmake:test_libgd",
+    "//examples/cmake:test_libpng",
+    "//examples/cmake:test_zlib",
+    "//examples/cmake_cares:test_c_ares",
+    "//examples/cmake_hello_world_lib:test_hello",
+    "//examples/cmake_nghttp2:test_nghttp2",
+    "//examples/ninja:test_ninja_version",
+    "//test:cmake_script_test_suite",
+]
+
 test_suite(
     name = "tests",
-    tests = [
-        "//examples/cmake:test_libgd",
-        "//examples/cmake:test_libpng",
-        "//examples/cmake:test_zlib",
-        "//examples/cmake_cares:test_c_ares",
-        "//examples/cmake_nghttp2:test_nghttp2",
-        "//examples/ninja:test_ninja_version",
-        "//test:cmake_script_test_suite",
-    ],
+    tests = tests,
+)
+
+test_suite(
+    name = "win_tests",
+    tags = ["windows"],
+    tests = tests,
 )

examples/cmake_hello_world_lib/BUILD

@@ -4,22 +4,45 @@
 filegroup(
     name = "srcs",
     srcs = glob(["**"]),
-    visibility = ["//visibility:public"]
+    visibility = ["//visibility:public"],
 )
 
 load("//tools/build_defs:cmake.bzl", "cmake_external")
+
 cmake_external(
     name = "libhello",
     lib_source = ":srcs",
     # pass include/version123 to C/C++ provider as include directory
-    out_include_dir = "include/version123"
+    out_include_dir = "include/version123",
+)
+
+cmake_external(
+    name = "libhello_win",
+    cmake_options = ["-G \"Visual Studio 15 2017 Win64\""],
+    generate_crosstool_file = True,
+    lib_source = ":srcs",
+    make_commands = ["MSBuild.exe INSTALL.vcxproj"],
+    # pass include/version123 to C/C++ provider as include directory
+    out_include_dir = "include/version123",
+    static_libraries = ["hello.lib"],
 )
 
 cc_binary(
     name = "libhello_example",
     # includes just hello.h, include directory: "include/version123"
     srcs = ["hello_client.c"],
-    deps = [":libhello"]
+    deps = select({
+        "@bazel_tools//src/conditions:windows": [":libhello_win"],
+        "//conditions:default": [":libhello"],
+    }),
+)
+
+sh_test(
+    name = "test_hello",
+    srcs = ["test_hello.sh"],
+    data = [":libhello_example"],
+    tags = ["windows"],
+    visibility = ["//:__pkg__"],
 )
 
 cmake_external(
@@ -27,11 +50,12 @@ cmake_external(
     lib_source = ":srcs",
     out_include_dir = "include",
     # the name of the static library != <name>.a, put it explicitly
-    static_libraries = ["libhello.a"]
+    static_libraries = ["libhello.a"],
 )
+
 cc_binary(
     name = "libhello_example123",
     # includes version123/hello.h, include directory: "include"
     srcs = ["hello_client_version123.c"],
-    deps = [":libhello123"]
+    deps = [":libhello123"],
 )

examples/cmake_hello_world_lib/test_hello.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+${TEST_SRCDIR}/rules_foreign_cc/examples/cmake_hello_world_lib/libhello_example