Convert to Android.bp

See build/soong/README.md for more information.

gen.mk is currently using build system internals in order to tell the
gen_*.sh scripts how to call the compiler. Soong genrules do not provide
the required information to call a compiler, so use a `cc_object {}` to
do the preprocessing steps, and pass the output from that into the
gen_*.sh scripts (cc_genrule).

It fixes the missing dependencies for the 2nd arch, and uses the correct
libc headers for the _vendor variant.

Bug: 66914194
Test: mmma external/minijail
Test: cd external/minijail; make all tests
Test: out/host/linux-x86/nativetest/system_unittest_gtest/system_unittest_gtest
Test: out/host/linux-x86/nativetest64/system_unittest_gtest/system_unittest_gtest
Test: cd external/minijail; ../../out/host/linux-x86/nativetest/syscall_filter_unittest_gtest/syscall_filter_unittest_gtest
Test: cd external/minijail; ../../out/host/linux-x86/nativetest64/syscall_filter_unittest_gtest/syscall_filter_unittest_gtest
Change-Id: Id116afb24677ea386f1b043c71c59d3b7ffd8696
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..a90d654
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,287 @@
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Common variables.
+// =========================================================
+libminijailSrcFiles = [
+    "bpf.c",
+    "libminijail.c",
+    "signal_handler.c",
+    "syscall_filter.c",
+    "syscall_wrapper.c",
+    "system.c",
+    "util.c",
+]
+
+unittestSrcFiles = [
+    "testrunner.cc",
+]
+
+minijailCommonLibraries = ["libcap"]
+
+cc_defaults {
+    name: "libminijail_flags",
+    cflags: [
+        "-DHAVE_SECUREBITS_H",
+        "-Wall",
+        "-Werror",
+    ],
+    target: {
+        darwin: {
+            enabled: false,
+        },
+    },
+}
+
+// Static library for generated code.
+// =========================================================
+cc_object {
+    name: "libminijail_gen_syscall_obj",
+    vendor_available: true,
+    srcs: ["gen_syscalls.c"],
+    cflags: [
+        "-dD",
+        "-E",
+    ],
+}
+
+cc_genrule {
+    name: "libminijail_gen_syscall",
+    vendor_available: true,
+    tool_files: ["gen_syscalls.sh"],
+    cmd: "$(location gen_syscalls.sh) $(in) $(out)",
+    srcs: [":libminijail_gen_syscall_obj"],
+    out: ["libsyscalls.c"],
+}
+
+cc_object {
+    name: "libminijail_gen_constants_obj",
+    vendor_available: true,
+    srcs: ["gen_constants.c"],
+    cflags: [
+        "-dD",
+        "-E",
+    ],
+}
+
+cc_genrule {
+    name: "libminijail_gen_constants",
+    vendor_available: true,
+    tool_files: ["gen_constants.sh"],
+    cmd: "$(location gen_constants.sh) $(in) $(out)",
+    srcs: [":libminijail_gen_constants_obj"],
+    out: ["libconstants.c"],
+}
+
+cc_library_static {
+    name: "libminijail_generated",
+    vendor_available: true,
+    defaults: ["libminijail_flags"],
+    host_supported: true,
+
+    target: {
+        android: {
+            generated_sources: [
+                "libminijail_gen_syscall",
+                "libminijail_gen_constants",
+            ],
+        },
+        host: {
+            srcs: [
+                "linux-x86/libconstants.gen.c",
+                "linux-x86/libsyscalls.gen.c",
+            ],
+        },
+    },
+}
+
+// libminijail shared and static library for target.
+// =========================================================
+cc_library {
+    name: "libminijail",
+    vendor_available: true,
+    defaults: ["libminijail_flags"],
+
+    srcs: libminijailSrcFiles,
+
+    static: {
+        whole_static_libs: ["libminijail_generated"] + minijailCommonLibraries,
+    },
+    shared: {
+        static_libs: ["libminijail_generated"],
+        shared_libs: minijailCommonLibraries,
+    },
+    export_include_dirs: ["."],
+}
+
+// Example ASan-ified libminijail shared library for target.
+// Commented out since it's only needed for local debugging.
+// =========================================================
+//cc_library_shared {
+//    name: "libminijail_asan",
+//    defaults: ["libminijail_flags"],
+//
+//    sanitize: {
+//        address: true,
+//    },
+//    relative_install_path: "asan",
+//    srcs: libminijailSrcFiles,
+//
+//    static_libs: ["libminijail_generated"],
+//    shared_libs: minijailCommonLibraries,
+//    export_include_dirs: ["."],
+//}
+
+// libminijail native unit tests using gtest.
+//
+// For a device, run with:
+// adb shell /data/nativetest/libminijail_unittest_gtest/libminijail_unittest_gtest
+//
+// For host, run with:
+// out/host/linux-x86/nativetest(64)/libminijail_unittest_gtest/libminijail_unittest_gtest
+// =========================================================
+cc_test {
+    name: "libminijail_unittest_gtest",
+    defaults: ["libminijail_flags"],
+    // TODO(b/31395668): Re-enable once the seccomp(2) syscall becomes available.
+    //host_supported: true
+
+    srcs: libminijailSrcFiles + ["libminijail_unittest.cc"] + unittestSrcFiles,
+
+    static_libs: ["libminijail_generated"],
+    shared_libs: minijailCommonLibraries,
+
+    target: {
+        android: {
+            cflags: ["-Wno-writable-strings"],
+            test_suites: ["device-tests"],
+        },
+        host: {
+            cflags: ["-DPRELOADPATH=\"/invalid\""],
+        },
+    },
+}
+
+// Syscall filtering native unit tests using gtest.
+//
+// For a device, run with:
+// adb shell /data/nativetest/syscall_filter_unittest_gtest/syscall_filter_unittest_gtest
+//
+// For host, run with:
+// out/host/linux-x86/nativetest(64)/syscall_filter_unittest_gtest/syscall_filter_unittest_gtest
+// =========================================================
+cc_test {
+    name: "syscall_filter_unittest_gtest",
+    defaults: ["libminijail_flags"],
+    host_supported: true,
+
+    srcs: [
+        "bpf.c",
+        "syscall_filter.c",
+        "util.c",
+        "syscall_filter_unittest.cc",
+    ] + unittestSrcFiles,
+
+    static_libs: ["libminijail_generated"],
+    shared_libs: minijailCommonLibraries,
+
+    target: {
+        android: {
+            test_suites: ["device-tests"],
+        },
+    },
+}
+
+// System functionality unit tests using gtest.
+//
+// For a device, run with:
+// adb shell /data/nativetest/system_unittest_gtest/system_unittest_gtest
+//
+// For host, run with:
+// out/host/linux-x86/nativetest(64)/system_unittest_gtest/system_unittest_gtest
+// =========================================================
+cc_test {
+    name: "system_unittest_gtest",
+    defaults: ["libminijail_flags"],
+    host_supported: true,
+
+    srcs: [
+        "system.c",
+        "util.c",
+        "system_unittest.cc",
+    ] + unittestSrcFiles,
+
+    static_libs: ["libminijail_generated"],
+    shared_libs: minijailCommonLibraries,
+
+    target: {
+        android: {
+            test_suites: ["device-tests"],
+        },
+    },
+}
+
+// libminijail_test executable for brillo_Minijail test.
+// =========================================================
+cc_test {
+    name: "libminijail_test",
+    defaults: ["libminijail_flags"],
+    test_suites: ["device-tests"],
+
+    gtest: false,
+
+    srcs: ["test/libminijail_test.cpp"],
+
+    shared_libs: [
+        "libbase",
+        "libminijail",
+    ],
+}
+
+// libminijail usage example.
+// =========================================================
+cc_binary {
+    name: "drop_privs",
+    defaults: ["libminijail_flags"],
+
+    // Don't build with ASan, but leave commented out for easy local debugging.
+    // sanitize: { address: true, },
+    srcs: ["examples/drop_privs.cpp"],
+
+    shared_libs: [
+        "libbase",
+        "libminijail",
+    ],
+}
+
+// minijail0 executable.
+// This is not currently used on Brillo/Android,
+// but it's convenient to be able to build it.
+// =========================================================
+cc_binary {
+    name: "minijail0",
+    defaults: ["libminijail_flags"],
+
+    cflags: [
+        "-Wno-missing-field-initializers",
+        "-DPRELOADPATH=\"/invalidminijailpreload.so\"",
+    ],
+    srcs: [
+        "elfparse.c",
+        "minijail0.c",
+    ],
+
+    static_libs: ["libminijail_generated"],
+    shared_libs: minijailCommonLibraries + ["libminijail"],
+}