Support Bazel builds. Fixes #16

.bazelrc

@@ -0,0 +1 @@
+common --enable_bzlmod

.github/workflows/build.yml

@@ -12,6 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        # When adding another, also add to copybara's github_check_runs.
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
         build_type: ['Release']
         preset: ['make', 'windows']
@@ -54,3 +55,21 @@ jobs:
           ${{ github.workspace }}/build/${{ matrix.build_type }}/libgemma.lib
           ${{ github.workspace }}/build/gemma
           ${{ github.workspace }}/build/libgemma.a
+
+  bazel:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
+        with:
+          egress-policy: audit  # cannot be block - runner does git checkout
+
+      - uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4.0.0
+
+      - uses: bazelbuild/setup-bazelisk@b39c379c82683a5f25d34f0d062761f62693e0b2 # v3.0.0
+
+      - uses: actions/cache@ab5e6d0c87105b4c9c2047343972218f562e4319 # v4.0.1
+        with:
+          path: ~/.cache/bazel
+          key: bazel-${{ runner.os }}
+      - run: bazel build -c opt --cxxopt=-std=c++20 //...

BUILD.bazel

@@ -25,21 +25,14 @@ cc_library(
     ],
     deps = [
         "//compression:compress",
-        # copybara:import_next_line:hwy
-        "//:algo",
-        # copybara:import_next_line:hwy
-        "//:dot",
-        # copybara:import_next_line:hwy
-        "//:hwy",
-        # copybara:import_next_line:hwy
-        "//:math",
-        # copybara:import_next_line:hwy
-        "//:matvec",
-        # copybara:import_next_line:hwy
-        "//:profiler",
-        # copybara:import_next_line:hwy
-        "//:thread_pool",
-        "//hwy/contrib/sort:vqsort",
+        "@hwy//:algo",
+        "@hwy//:dot",
+        "@hwy//:hwy",
+        "@hwy//:math",
+        "@hwy//:matvec",
+        "@hwy//:profiler",
+        "@hwy//:thread_pool",
+        "@hwy//hwy/contrib/sort:vqsort",
     ],
 )
 
@@ -49,8 +42,7 @@ cc_library(
         "util/args.h",
     ],
     deps = [
-        # copybara:import_next_line:hwy
-        "//:hwy",
+        "@hwy//:hwy",
     ],
 )
 
@@ -61,8 +53,7 @@ cc_library(
     ],
     deps = [
         ":args",
-        # copybara:import_next_line:hwy
-        "//:hwy",
+        "@hwy//:hwy",
     ],
 )
 
@@ -78,19 +69,13 @@ cc_library(
     deps = [
         ":args",
         ":transformer_ops",
-        "//base",
         "//compression:compress",
-        # copybara:import_next_line:hwy
-        "//:hwy",
-        # copybara:import_next_line:hwy
-        "//:matvec",
-        # copybara:import_next_line:hwy
-        "//:nanobenchmark",  # timer
-        # copybara:import_next_line:hwy
-        "//:profiler",
-        # copybara:import_next_line:hwy
-        "//:thread_pool",
-        ":sentencepiece_processor",
+        "@hwy//:hwy",
+        "@hwy//:matvec",
+        "@hwy//:nanobenchmark",  # timer
+        "@hwy//:profiler",
+        "@hwy//:thread_pool",
+        "@com_google_sentencepiece//:sentencepiece_processor",
     ],
 )
 
@@ -104,13 +89,9 @@ cc_binary(
         ":args",
         ":gemma_lib",
         "//compression:compress",
-        # copybara:import_next_line:hwy
-        "//:hwy",
-        # copybara:import_next_line:hwy
-        "//:nanobenchmark",
-        # copybara:import_next_line:hwy
-        "//:profiler",
-        # copybara:import_next_line:hwy
-        "//:thread_pool",
+        "@hwy//:hwy",
+        "@hwy//:nanobenchmark",
+        "@hwy//:profiler",
+        "@hwy//:thread_pool",
     ],
 )

DEVELOPERS.md

@@ -127,13 +127,13 @@ working with weights, kv cache and activations (e.g. you might have multiple kv
 caches and activations for a single set of weights) more directly rather than
 only using a Gemma object.
 
-## Use the tokenizer in the Gemma object (or interact with the Tokenizer object directly)
+### Use the tokenizer in the Gemma object (or interact with the Tokenizer object directly)
 
 You pretty much only do things with the tokenizer, call `Encode()` to go from
 string prompts to token id vectors, or `Decode()` to go from token id vector
 outputs from the model back to strings.
 
-## The main entrypoint for generation is `GenerateGemma()`
+### The main entrypoint for generation is `GenerateGemma()`
 
 Calling into `GenerateGemma` with a tokenized prompt will 1) mutate the
 activation values in `model` and 2) invoke StreamFunc - a lambda callback for
@@ -150,19 +150,28 @@ constrained decoding type of use cases where you want to force the generation
 to fit a grammar. If you're not doing this, you can send an empty lambda as a
 no-op which is what `run.cc` does.
 
-## If you want to invoke the neural network forward function directly call the `Transformer()` function
+### If you want to invoke the neural network forward function directly call the `Transformer()` function
 
 For high-level applications, you might only call `GenerateGemma()` and never
 interact directly with the neural network, but if you're doing something a bit
 more custom you can call transformer which performs a single inference
 operation on a single token and mutates the Activations and the KVCache through
 the neural network computation.
 
-## For low level operations, defining new architectures, call `ops.h` functions directly
+### For low level operations, defining new architectures, call `ops.h` functions directly
 
 You use `ops.h` if you're writing other NN architectures or modifying the
 inference path of the Gemma model.
 
+## Building with Bazel
+
+The sentencepiece library we depend on requires some additional work to build
+with the Bazel build system. First, it does not export its BUILD file, so we
+provide `bazel/sentencepiece.bazel`. Second, it ships with a vendored subset of
+the Abseil library. `bazel/com_google_sentencepiece.patch` changes the code to
+support Abseil as a standalone dependency without third_party/ prefixes, similar
+to the transforms we apply to Gemma via Copybara.
+
 ## Discord
 
 We're also trying out a discord server for discussion here -

MODULE.bazel

@@ -3,12 +3,57 @@ module(
     version = "0.1.0",
 )
 
-bazel_dep(
-    name = "rules_license",
-    version = "0.0.7",
+bazel_dep(name = "rules_license", version = "0.0.7")
+bazel_dep(name = "googletest", version = "1.14.0")
+
+# Copied from Highway because Bazel does not load them transitively
+bazel_dep(name = "bazel_skylib", version = "1.4.1")
+bazel_dep(name = "rules_cc", version = "0.0.9")
+bazel_dep(name = "platforms", version = "0.0.7")
+
+http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "hwy",
+    urls = ["https://github.com/google/highway/archive/refs/tags/1.1.0.zip"],
+    integrity = "sha256-zkJX2SwL4wQ0nHMsURW7MDLEf43vFSnqhSUsUM6eQmY=",
+    strip_prefix = "highway-1.1.0",
 )
 
-bazel_dep(
+http_archive(
     name = "com_google_sentencepiece",
-    version = "0.1.96",
+    sha256 = "8409b0126ebd62b256c685d5757150cf7fcb2b92a2f2b98efb3f38fc36719754",
+    strip_prefix = "sentencepiece-0.1.96",
+    urls = ["https://github.com/google/sentencepiece/archive/refs/tags/v0.1.96.zip"],
+    build_file = "@//bazel:sentencepiece.bazel",
+    patches = ["@//bazel:com_google_sentencepiece.patch"],
+    patch_args = ["-p1"],
+)
+
+# For sentencepiece
+http_archive(
+    name = "darts_clone",
+    build_file_content = """
+licenses(["notice"])
+exports_files(["LICENSE"])
+package(default_visibility = ["//visibility:public"])
+cc_library(
+    name = "darts_clone",
+    hdrs = [
+        "include/darts.h",
+    ],
+)
+""",
+    sha256 = "c97f55d05c98da6fcaf7f9ecc6a6dc6bc5b18b8564465f77abff8879d446491c",
+    strip_prefix = "darts-clone-e40ce4627526985a7767444b6ed6893ab6ff8983",
+    urls = [
+        "https://github.com/s-yata/darts-clone/archive/e40ce4627526985a7767444b6ed6893ab6ff8983.zip",
+    ],
+)
+# ABSL on 2023-10-18
+http_archive(
+    name = "com_google_absl",
+    sha256 = "f841f78243f179326f2a80b719f2887c38fe226d288ecdc46e2aa091e6aa43bc",
+    strip_prefix = "abseil-cpp-9687a8ea750bfcddf790372093245a1d041b21a3",
+    urls = ["https://github.com/abseil/abseil-cpp/archive//9687a8ea750bfcddf790372093245a1d041b21a3.tar.gz"],
 )

README.md

@@ -175,6 +175,14 @@ cmake --build --preset windows -j [number of parallel threads to use]
 
 If the build is successful, you should now have a `gemma.exe` executable in the `build/` directory.
 
+#### Bazel
+
+```sh
+bazel build -c opt --cxxopt=-std=c++20 :gemma
+```
+
+If the build is successful, you should now have a `gemma` executable in the `bazel-bin/` directory.
+
 ### Step 4: Run
 
 You can now run `gemma` from inside the `build/` directory.

WORKSPACE

@@ -1,24 +1,4 @@
 workspace(name = "gemma")
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
-
-maybe(
-    http_archive,
-    name = "rules_license",
-    sha256 = "4531deccb913639c30e5c7512a054d5d875698daeb75d8cf90f284375fe7c360",
-    urls = [
-        "https://github.com/bazelbuild/rules_license/releases/download/0.0.7/rules_license-0.0.7.tar.gz",
-    ],
-)
-
-maybe(
-    http_archive,
-    name = "com_google_sentencepiece",
-    sha256 = "8409b0126ebd62b256c685d5757150cf7fcb2b92a2f2b98efb3f38fc36719754",
-    strip_prefix = "sentencepiece-0.1.96",
-    urls = ["https://github.com/google/sentencepiece/archive/refs/tags/v0.1.96.zip"],
-    build_file = "@//third_party:sentencepiece.bazel",
-    patches = ["@//third_party:com_google_sentencepiece.patch"],
-    patch_args = ["-p1"],
-)
+# This file marks the root of the Bazel workspace.
+# See MODULE.bazel for external dependencies setup.

bazel/BUILD

@@ -0,0 +1,4 @@
+package(
+    default_applicable_licenses = ["//:license"],
+    default_visibility = ["//:__subpackages__"],
+)