test: add meson_simple test

Test meson rule and the new support for extra targets such as
introspect.

Author: jjmaestro

examples/meson_simple/BUILD.bazel

@@ -0,0 +1,46 @@
+load("@rules_cc//cc:defs.bzl", "cc_test")
+load("@rules_foreign_cc//foreign_cc:defs.bzl", "meson")
+load("@rules_shell//shell:sh_test.bzl", "sh_test")
+
+meson(
+    name = "meson_lib",
+    build_data = ["//meson_simple/code:clang_wrapper.sh"],
+    env = select({
+        "//:windows": {
+            "CLANG_WRAPPER": "$(execpath //meson_simple/code:clang_wrapper.sh)",
+            "CXX_FLAGS": "/MD",
+        },
+        "//conditions:default": {
+            "CLANG_WRAPPER": "$(execpath //meson_simple/code:clang_wrapper.sh)",
+            "CXX_FLAGS": "-fPIC",
+        },
+    }),
+    lib_source = "//meson_simple/code:srcs",
+    out_static_libs = ["liba.a"],
+)
+
+cc_test(
+    name = "test_lib",
+    srcs = [
+        "test_libb.cpp",
+    ],
+    deps = [
+        ":meson_lib",
+    ],
+)
+
+meson(
+    name = "meson_lib-introspect",
+    lib_source = "//meson_simple/code:srcs",
+    out_data_files = ["introspect.json"],
+    out_include_dir = "",
+    targets = ["introspect"],
+)
+
+sh_test(
+    name = "test_introspect",
+    srcs = ["test_introspect.sh"],
+    args = ["$(location meson_lib-introspect)"],
+    data = [":meson_lib-introspect"],
+    deps = ["@bazel_tools//tools/bash/runfiles"],
+)

examples/meson_simple/code/BUILD.bazel

@@ -0,0 +1,11 @@
+exports_files(["clang_wrapper.sh"])
+
+filegroup(
+    name = "srcs",
+    srcs = [
+        "liba.cpp",
+        "liba.h",
+        "meson.build",
+    ],
+    visibility = ["//meson_simple:__subpackages__"],
+)

examples/meson_simple/code/clang_wrapper.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+
+if [[ $(uname) == *"NT"* ]]; then
+ # If Windows
+  exec clang-cl "$@"
+else
+  exec clang "$@"
+fi

examples/meson_simple/code/liba.cpp

@@ -0,0 +1,3 @@
+#include "liba.h"
+
+std::string hello_liba(void) { return "Hello from LIBA!"; }

examples/meson_simple/code/liba.h

@@ -0,0 +1,10 @@
+#ifndef LIBA_H_
+#define LIBA_H_ (1)
+
+#include <stdio.h>
+
+#include <string>
+
+std::string hello_liba(void);
+
+#endif

examples/meson_simple/code/meson.build

@@ -0,0 +1,16 @@
+project('liba', 'cpp')
+
+builddir = 'rules_foreign_cc_build'
+
+cxx = meson.get_compiler('cpp')
+
+liba = static_library(
+  'a',
+  'liba.cpp',
+  cpp_args: cxx.get_supported_arguments(),
+  include_directories: include_directories('.'),
+  install: true,
+  install_dir: join_paths(get_option('prefix'), 'lib'),
+)
+
+install_headers('liba.h', subdir: 'include')

examples/meson_simple/test_introspect.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+# --- begin runfiles.bash initialization ---
+# The runfiles library itself defines rlocation which you would need to look
+# up the library's runtime location, thus we have a chicken-and-egg problem.
+#
+# Copy-pasted from Bazel's Bash runfiles library (tools/bash/runfiles/runfiles.bash).
+set -euo pipefail
+if [[ ! -d "${RUNFILES_DIR:-/dev/null}" && ! -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+  if [[ -f "$0.runfiles_manifest" ]]; then
+    export RUNFILES_MANIFEST_FILE="$0.runfiles_manifest"
+  elif [[ -f "$0.runfiles/MANIFEST" ]]; then
+    export RUNFILES_MANIFEST_FILE="$0.runfiles/MANIFEST"
+  elif [[ -f "$0.runfiles/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+    export RUNFILES_DIR="$0.runfiles"
+  fi
+fi
+if [[ -f "${RUNFILES_DIR:-/dev/null}/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+  source "${RUNFILES_DIR}/bazel_tools/tools/bash/runfiles/runfiles.bash"
+elif [[ -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+  source "$(grep -m1 "^bazel_tools/tools/bash/runfiles/runfiles.bash " \
+            "$RUNFILES_MANIFEST_FILE" | cut -d ' ' -f 2-)"
+else
+  echo >&2 "ERROR: cannot find @bazel_tools//tools/bash/runfiles:runfiles.bash"
+  exit 1
+fi
+# --- end runfiles.bash initialization ---
+
+[[ -f $(rlocation $TEST_WORKSPACE/$1) ]] && exit 0
+exit 1

examples/meson_simple/test_libb.cpp

@@ -0,0 +1,13 @@
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+#include "include/liba.h"
+
+int main(int argc, char* argv[]) {
+    std::string result = hello_liba();
+    if (result != "Hello from LIBA!") {
+        throw std::runtime_error("Wrong result: " + result);
+    }
+    std::cout << "Everything's fine!";
+}