Add initial bazel build support for snappy.

PiperOrigin-RevId: 524135175
diff --git a/.gitignore b/.gitignore
index c4b2425..826af25 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,5 @@
 
 # Build directory.
 build/
+/bazel-*
 out/
diff --git a/opensource/.bazelrc b/opensource/.bazelrc
new file mode 100644
index 0000000..3843446
--- /dev/null
+++ b/opensource/.bazelrc
@@ -0,0 +1,2 @@
+# googletest requires C++14 or above
+build --cxxopt='-std=c++17'
diff --git a/opensource/BUILD.bazel b/opensource/BUILD.bazel
new file mode 100644
index 0000000..1c60d28
--- /dev/null
+++ b/opensource/BUILD.bazel
@@ -0,0 +1,199 @@
+# Copyright 2023 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+SNAPPY_VERSION = (1, 1, 10)
+
+cc_library(
+    name = "config",
+    hdrs = ["config.h"],
+    defines = ["HAVE_CONFIG_H"]
+)
+
+cc_library(
+    name = "snappy-stubs-public",
+    hdrs = [":snappy-stubs-public.h"],
+)
+
+cc_library(
+    name = "snappy-stubs-internal",
+    srcs = ["snappy-stubs-internal.cc"],
+    hdrs = ["snappy-stubs-internal.h"],
+    deps = [
+        ":config",
+        ":snappy-stubs-public",
+    ],
+)
+
+cc_library(
+    name = "snappy",
+    srcs = [
+        "snappy.cc",
+        "snappy-internal.h",
+        "snappy-sinksource.cc",
+    ],
+    hdrs = [
+        "snappy.h",
+        "snappy-sinksource.h",
+    ],
+    copts = [
+        "-Wno-sign-compare",
+    ],
+    deps = [
+        ":config",
+        ":snappy-stubs-internal",
+        ":snappy-stubs-public",
+    ],
+)
+
+cc_library(
+    name = "snappy-c",
+    srcs = ["snappy-c.cc"],
+    hdrs = ["snappy-c.h"],
+    deps = [":snappy"],
+)
+
+filegroup(
+    name = "testdata",
+    srcs = glob(["testdata/*"]),
+)
+
+cc_library(
+    name = "snappy-test",
+    testonly = True,
+    srcs = [
+        "snappy-test.cc",
+        "snappy_test_data.cc",
+    ],
+    hdrs = [
+        "snappy-test.h",
+        "snappy_test_data.h",
+    ],
+    deps = [":snappy-stubs-internal"],
+)
+
+cc_test(
+    name = "snappy_benchmark",
+    srcs = ["snappy_benchmark.cc"],
+    data = [":testdata"],
+    deps = [
+        ":snappy",
+        ":snappy-test",
+        "//third_party/benchmark:benchmark_main",
+    ],
+)
+
+cc_test(
+    name = "snappy_unittest",
+    srcs = [
+        "snappy_unittest.cc",
+    ],
+    data = [":testdata"],
+    deps = [
+        ":snappy",
+        ":snappy-test",
+        "//third_party/googletest:gtest_main",
+    ],
+)
+
+# Generate a config.h similar to what cmake would produce.
+genrule(
+    name = "config_h",
+    outs = ["config.h"],
+    cmd = """cat <<EOF >$@
+#define HAVE_STDDEF_H 1
+#define HAVE_STDINT_H 1
+#ifdef __has_builtin
+#  if !defined(HAVE_BUILTIN_EXPECT) && __has_builtin(__builtin_expect)
+#    define HAVE_BUILTIN_EXPECT 1
+#  endif
+#  if !defined(HAVE_BUILTIN_CTZ) && __has_builtin(__builtin_ctzll)
+#    define HAVE_BUILTIN_CTZ 1
+#  endif
+#  if !defined(HAVE_BUILTIN_PREFETCH) && __has_builtin(__builtin_prefetech)
+#    define HAVE_BUILTIN_PREFETCH 1
+#  endif
+#elif defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#  ifndef HAVE_BUILTIN_EXPECT
+#    define HAVE_BUILTIN_EXPECT 1
+#  endif
+#  ifndef HAVE_BUILTIN_CTZ
+#    define HAVE_BUILTIN_CTZ 1
+#  endif
+#  ifndef HAVE_BUILTIN_PREFETCH
+#    define HAVE_BUILTIN_PREFETCH 1
+#  endif
+#endif
+
+#ifdef __has_include
+#  if !defined(HAVE_BYTESWAP_H) && __has_include(<byteswap.h>)
+#    define HAVE_BYTESWAP_H 1
+#  endif
+#  if !defined(HAVE_UNISTD_H) && __has_include(<unistd.h>)
+#    define HAVE_UNISTD_H 1
+#  endif
+#  if !defined(HAVE_SYS_ENDIAN_H) && __has_include(<sys/endian.h>)
+#    define HAVE_SYS_ENDIAN_H 1
+#  endif
+#  if !defined(HAVE_SYS_MMAN_H) && __has_include(<sys/mman.h>)
+#    define HAVE_SYS_MMAN_H 1
+#  endif
+#  if !defined(HAVE_SYS_UIO_H) && __has_include(<sys/uio.h>)
+#    define HAVE_SYS_UIO_H 1
+#  endif
+#  if !defined(HAVE_SYS_TIME_H) && __has_include(<sys/time.h>)
+#    define HAVE_SYS_TIME_H 1
+#  endif
+#endif
+
+#ifndef SNAPPY_IS_BIG_ENDIAN
+#  ifdef __s390x__
+#    define SNAPPY_IS_BIG_ENDIAN 1
+#  elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#    define SNAPPY_IS_BIG_ENDIAN 1
+#  endif
+#endif
+EOF
+""",
+)
+
+genrule(
+    name = "snappy_stubs_public_h",
+    srcs = ["snappy-stubs-public.h.in"],
+    outs = ["snappy-stubs-public.h"],
+    # Define HAVE_SYS_UIO_H_01 to 1; we just assume it's available.
+    # Set the version numbers.
+    cmd = ("""sed -e 's/$${\\(.*\\)_01}/1/g' \
+           -e 's/$${PROJECT_VERSION_MAJOR}/%d/g' \
+           -e 's/$${PROJECT_VERSION_MINOR}/%d/g' \
+           -e 's/$${PROJECT_VERSION_PATCH}/%d/g' \
+    $< >$@""" % SNAPPY_VERSION),
+)
diff --git a/opensource/WORKSPACE b/opensource/WORKSPACE
new file mode 100644
index 0000000..7e60888
--- /dev/null
+++ b/opensource/WORKSPACE
@@ -0,0 +1,27 @@
+# Copyright 2023 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.