Upgrade to Bazel 7, Ubuntu 24.04 (fixes #152)

.bazelrc

@@ -2,5 +2,14 @@
 try-import user.bazelrc
 
 # Use C++17.
-common --cxxopt='-std=c++17'
-common --host_cxxopt='-std=c++17'
+build --cxxopt=-std=c++17
+build --host_cxxopt=-std=c++17
+
+# Use Clang.
+build --action_env=CC=clang
+build --action_env=CXX=clang++
+
+# Use `WORKSPACE.bazel` instead of Bzlmod (`MODULE.bazel`).
+# TODO - migrate to Bzlmod.
+common --noenable_bzlmod
+common --enable_workspace

.bazelversion

@@ -1 +1 @@
-5.4.0
+7.4.1

.github/workflows/ci-format.yml

@@ -8,19 +8,9 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-      with:
-        submodules: recursive
-
-    - name: Mount bazel cache
-      uses: actions/cache@v3
-      with:
-        path: "~/.cache/bazel"  # See https://docs.bazel.build/versions/master/output_directories.html
-        key: format-${{ hashFiles('**/*_deps.bzl', '**/*.bazelrc') }}
-        restore-keys: |
-          format
 
     - name: Run format.sh
       run: ./format.sh

.github/workflows/ci-native.yml

@@ -7,29 +7,50 @@ on:
     branches: [ master ]
   schedule:
     # Run daily at 00:00 (https://crontab.guru/#0_0_*_*_*).
-    - cron: "0 0 * * *"
+    - cron: "0 0 * * *"  # Allow manual triggering of the workflow.
+  # https://docs.github.com/en/actions/managing-workflow-runs-and-deployments/managing-workflow-runs/manually-running-a-workflow
+  workflow_dispatch:
 
 jobs:
   build:
-    runs-on: ubuntu-22.04
+
+    strategy:
+      matrix:
+        # We only test on the oldest version we want to support and latest.
+        # We trust that things also work for versions in the middle.
+        os: [ubuntu-22.04, ubuntu-latest]
+        # See Bazelisk README for legal values.
+        # TODO - Add `latest` once it is supported. Requires using Bzlmod.
+        bazel_version: [7.x]
+      # Don't abort other runs when one of them fails, to ease debugging.
+      fail-fast: false
+
+    runs-on: ${{ matrix.os }}
+
     env:
-      XDG_CACHE_HOME: ~/.cache/bazel-repo
+      # This tells Bazelisk (installed as `bazel`) to use specified version.
+      # https://github.com/bazelbuild/bazelisk?tab=readme-ov-file#how-does-bazelisk-know-which-bazel-version-to-run
+      USE_BAZEL_VERSION: ${{ matrix.bazel_version }}
+      CACHE_KEY: ${{ matrix.os }}_bazel-${{ matrix.bazel_version }}
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        submodules: recursive
 
     - name: Install p4c system dependencies (Flex, Bison, GMP)
-      run: sudo apt-get update && sudo apt-get install bison flex libfl-dev libgmp-dev
+      run: sudo apt install bison flex libfl-dev libgmp-dev
 
-    - name: Mount bazel caches
-      uses: actions/cache/restore@v3
-      id: restore-cache
+    - name: Mount bazel cache
+      uses: actions/cache/restore@v4
       with:
+        # See https://docs.bazel.build/versions/master/output_directories.html
         path: "~/.cache/bazel"
-        key: bazel-${{ hashFiles('**/*_deps.bzl', '**/*.bazelrc') }}-${{ github.ref_name }}
+        # Create a new cache entry whenever Bazel files change.
+        # See https://docs.github.com/en/actions/guides/caching-dependencies-to-speed-up-workflows
+        key: ${{ env.CACHE_KEY }}-${{ hashFiles('**/*.bazel*', '**/*.bzl') }}
         restore-keys: |
-          bazel-${{ hashFiles('**/*_deps.bzl', '**/*.bazelrc') }}
-          bazel
+          ${{ env.CACHE_KEY }}
 
     - name: Save start time
       uses: josStorer/get-current-time@v2
@@ -38,44 +59,45 @@ jobs:
         # Unix timestamp -- seconds since 1970.
         format: X
 
-    - name: bazel build //...
-      run: |
-        bazel \
-          --bazelrc=$GITHUB_WORKSPACE/.github/workflows/ci.bazelrc \
-          build //...
+    - name: Build
+      run: bazel build --test_output=errors //...
 
-    - name: bazel test //...
-      run: |
-        bazel \
-          --bazelrc=$GITHUB_WORKSPACE/.github/workflows/ci.bazelrc \
-          test //...
+    - name: Test
+      run: bazel test --test_output=errors //...
 
     - name: Save end time
+      # Always save the end time so we can calculate the build duration.
+      if: always()
       uses: josStorer/get-current-time@v2
       id: end-time
       with:
         # Unix timestamp -- seconds since 1970.
         format: X
 
     - name: Calculate build duration
+      # Always calculate the build duration so we can update the cache if needed.
+      if: always()
       run: |
         START=${{ steps.start-time.outputs.formattedTime }}
         END=${{ steps.end-time.outputs.formattedTime }}
         DURATION=$(( $END - $START ))
         echo "duration=$DURATION" | tee "$GITHUB_ENV"
 
-    # Bazel's `--disk-cache` currently grows without bounds, so we remove files
-    # that haven't been accessed in 30+ days manually.
-    # github.com/bazelbuild/bazel/issues/5139 tracks fixing this in Bazel.
-    - name: Compress disk cache
-      run: find $HOME/.cache/bazel -type f -atime +30 -delete
+    - name: Compress cache
+      # Always compress the cache so we can update the cache if needed.
+      if: always()
+      run: rm -rf $(bazel info repository_cache)
 
-    - name: Save cache
-      uses: actions/cache/save@v3
-      # We create a new cache entry if either of the following is true:
-      # - We are on the master branch.
-      # - It took more than 5 minutes to build and test.
-      if: github.ref_name == 'master' || env.duration > 300
+    - name: Save bazel cache
+      uses: actions/cache/save@v4
+      # Only create a new cache entry if we're on the main branch or the build takes >3mins.
+      #
+      # NOTE: Even though `always()` evaluates to true, and `true && x == x`,
+      # the `always() &&` prefix is not redundant! The call to `always()` has a
+      # side effect, which is to override the default behavior of automagically
+      # canceling this step if a previous step failed.
+      # (Don't blame me, blame GitHub Actions!)
+      if: always() && (github.ref_name == 'main' || env.duration > 180)
       with:
-        key: ${{ steps.restore-cache.outputs.cache-primary-key }}-${{ github.run_id }}
         path: "~/.cache/bazel"
+        key: ${{ env.CACHE_KEY }}-${{ hashFiles('**/*.bazel*', '**/*.bzl') }}-${{ github.run_id }}

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 bazel-*
 user.bazelrc
+buildifier

BUILD.bazel

@@ -1,10 +1,3 @@
-load("@com_github_bazelbuild_buildtools//buildifier:def.bzl", "buildifier")
-
 package(licenses = ["notice"])
 
 exports_files(["LICENSE"])
-
-buildifier(
-    name = "buildifier",
-    lint_mode = "fix",
-)

WORKSPACE.bazel

@@ -12,11 +12,13 @@ load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
 
-load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies", "rules_proto_toolchains")
+load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies")
 
 rules_proto_dependencies()
 
-rules_proto_toolchains()
+load("@rules_proto//proto:setup.bzl", "rules_proto_setup")
+
+rules_proto_setup()
 
 # -- P4{C, Runtime} + transitive dependencies ----------------------------------
 
@@ -48,45 +50,6 @@ load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
 
 grpc_extra_deps()
 
-# -- Buildifier (Bazel file formatter) + transitive dependencies ---------------
-
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
-http_archive(
-    name = "io_bazel_rules_go",
-    sha256 = "2b1641428dff9018f9e85c0384f03ec6c10660d935b750e3fa1492a281a53b0f",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.29.0/rules_go-v0.29.0.zip",
-        "https://github.com/bazelbuild/rules_go/releases/download/v0.29.0/rules_go-v0.29.0.zip",
-    ],
-)
-
-load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
-
-go_rules_dependencies()
-
-go_register_toolchains()
-
-http_archive(
-    name = "bazel_gazelle",
-    sha256 = "b85f48fa105c4403326e9525ad2b2cc437babaa6e15a3fc0b1dbab0ab064bc7c",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.22.2/bazel-gazelle-v0.22.2.tar.gz",
-        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.22.2/bazel-gazelle-v0.22.2.tar.gz",
-    ],
-)
-
-load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
-
-gazelle_dependencies(go_repository_default_config = "@//:WORKSPACE.bazel")
-
-http_archive(
-    name = "com_github_bazelbuild_buildtools",
-    sha256 = "0d3ca4ed434958dda241fb129f77bd5ef0ce246250feed2d5a5470c6f29a77fa",
-    strip_prefix = "buildtools-4.0.0",
-    url = "https://github.com/bazelbuild/buildtools/archive/4.0.0.tar.gz",
-)
-
 # -- Load Rules Foreign CC -----------------------------------------------------
 # Used for Z3.
 

format.sh

@@ -1,5 +1,20 @@
 #!/bin/bash
+#
 # Formats source files according to Google's style guide. Requires clang-format.
+# 
+# If you're on macOS with Apple silicon (M1, M2, M3, ...), call using
+# ```
+# PLATFORM=darown-arm64 ./format.sh
+# ```
+# 
+# If you're on macOS with Intel silicon, call using
+# ```
+# PLATFORM=darown-amd64 ./format.sh
+# ```
+# and similarly for other platforms.
+
+# Possible values: {linux, darwin}_{amd64, arm64}.
+PLATFORM=${PLATFORM:-linux-amd64}
 
 # Only files with these extensions will be formatted by clang-format.
 CLANG_FORMAT_EXTENSIONS="cc|h|proto"
@@ -10,4 +25,8 @@ find . -not -path "./third_party/**" \
   | xargs clang-format --verbose -style=google -i
 
 # Run buildifier (Bazel file formatter).
-bazel run //:buildifier
+BUILDIFIER="buildifier-$PLATFORM"
+wget "https://github.com/bazelbuild/buildtools/releases/download/v7.3.1/$BUILDIFIER"
+mv $BUILDIFIER buildifier
+chmod +x buildifier
+./buildifier --lint=fix -r .

gutils/proto.cc

@@ -26,17 +26,17 @@ class StringErrorCollector : public google::protobuf::io::ErrorCollector {
   StringErrorCollector(const StringErrorCollector &) = delete;
   StringErrorCollector &operator=(const StringErrorCollector &) = delete;
 
-  // Implementation of protobuf::io::ErrorCollector::AddError.
-  void AddError(int line, int column, const std::string &message) override {
+  // Implementation of protobuf::io::ErrorCollector::RecordError.
+  void RecordError(int line, int column, std::string_view message) override {
     if (error_text_ != nullptr) {
       absl::SubstituteAndAppend(error_text_, "$0($1): $2\n", line, column,
                                 message);
     }
   }
 
-  // Implementation of protobuf::io::ErrorCollector::AddWarning.
-  void AddWarning(int line, int column, const std::string &message) override {
-    AddError(line, column, message);
+  // Implementation of protobuf::io::ErrorCollector::RecordWarning.
+  void RecordWarning(int line, int column, std::string_view message) override {
+    RecordError(line, column, message);
   }
 
  private:

gutils/protocol_buffer_matchers.cc

@@ -23,6 +23,7 @@
 #include <cstring>
 #include <ostream>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "absl/log/check.h"
@@ -52,14 +53,14 @@ class StringErrorCollector : public google::protobuf::io::ErrorCollector {
   explicit StringErrorCollector(std::string* error_text)
       : error_text_(error_text) {}
 
-  void AddError(int line, int column, const std::string& message) override {
+  void RecordError(int line, int column, std::string_view message) override {
     absl::SubstituteAndAppend(error_text_, "$0($1): $2\n", line, column,
-                              message.c_str());
+                              message);
   }
 
-  void AddWarning(int line, int column, const std::string& message) override {
+  void RecordWarning(int line, int column, std::string_view message) override {
     absl::SubstituteAndAppend(error_text_, "$0($1): $2\n", line, column,
-                              message.c_str());
+                              message);
   }
 
  private: