Migrate to bzlmod with Bazel version 7.6.1

.bazelversion

@@ -0,0 +1 @@
+7.6.1

.gitignore

@@ -2,3 +2,4 @@ build
 llvm-project
 llvm-build
 bazel-*
+MODULE.bazel.lock

BZLMOD_MIGRATION.md

@@ -0,0 +1,87 @@
+# Bzlmod Migration Guide
+
+This repository has been migrated to use Bazel's bzlmod system with Bazel version 7.6.1.
+
+## What Changed
+
+### Bazel Version
+- Updated `.bazelversion` files to 7.6.1 for both root and stablehlo workspaces
+
+### Module Configuration
+- Added `MODULE.bazel` files for both root (mlir-hlo) and stablehlo workspaces
+- Configured module dependencies from Bazel Central Registry:
+  - `bazel_skylib` (1.3.0)
+  - `rules_cc` (0.0.9)
+  - `rules_python` (0.30.0)
+  - `rules_shell` (0.2.0)
+  - `apple_support` (1.5.0)
+  - `zlib` (1.3.1.bcr.3) - Used by LLVM
+  - `zstd` (1.5.6) - Used by LLVM
+
+### LLVM Dependencies (Hybrid Approach)
+Since LLVM doesn't support bzlmod natively, we use `WORKSPACE.bzlmod` files to manage the LLVM project dependency:
+- `llvm-raw`: The raw LLVM source archive
+- `llvm-project`: Configured LLVM project via `llvm_configure`
+
+Note: `zlib` and `zstd` are now managed through the Bazel Central Registry (BCR) in MODULE.bazel files with repo_name mappings (`llvm_zlib` and `llvm_zstd`) for LLVM compatibility.
+
+### File Structure
+```
+mlir-hlo/
+├── .bazelversion (7.6.1)
+├── MODULE.bazel (bzlmod dependencies)
+├── WORKSPACE.bzlmod (LLVM dependencies)
+├── WORKSPACE (kept for compatibility)
+├── .gitignore (excludes MODULE.bazel.lock files)
+└── stablehlo/
+    ├── .bazelversion (7.6.1)
+    ├── MODULE.bazel (bzlmod dependencies)
+    ├── WORKSPACE.bzlmod (LLVM dependencies)
+    └── WORKSPACE.bazel (kept for compatibility)
+```
+
+### Lock Files
+`MODULE.bazel.lock` files are generated by Bazel to ensure reproducible builds but are excluded from version control via `.gitignore`. They will be regenerated automatically when you run Bazel commands.
+
+## Building
+
+The migration is transparent to users. Build commands remain the same:
+
+```bash
+# From root workspace
+bazel build //path/to:target
+
+# From stablehlo workspace
+cd stablehlo && bazel build //:target
+```
+
+## Benefits of Bzlmod
+
+1. **Dependency Management**: Automatic version resolution through Bazel Central Registry
+2. **Better Isolation**: Each workspace can have its own module configuration
+3. **Reproducibility**: MODULE.bazel.lock files ensure reproducible builds
+4. **Future-proof**: Bzlmod is the default in Bazel 7.x and beyond
+5. **Centralized Dependencies**: Common dependencies like zlib and zstd are managed through BCR
+
+## Hybrid Approach
+
+We use a hybrid approach (bzlmod + WORKSPACE.bzlmod) because:
+- LLVM doesn't have a MODULE.bazel file
+- WORKSPACE.bzlmod is the recommended way to handle non-bzlmod dependencies in Bazel 7.x
+- This allows gradual migration as more dependencies adopt bzlmod
+- Common dependencies (zlib, zstd) are managed through BCR when possible
+
+## Verification
+
+To verify the migration:
+
+```bash
+# Check Bazel version
+bazel --version  # Should show 7.6.1
+
+# View module dependency graph
+bazel mod graph
+
+# Test LLVM dependency resolution
+bazel build --nobuild @llvm-project//llvm:Support
+```

MODULE.bazel

@@ -0,0 +1,33 @@
+# Copyright 2020 The OpenXLA Authors.
+#
+# 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
+#
+#      https://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.
+module(
+    name = "mlir-hlo",
+    version = "0.0.0",
+)
+
+bazel_dep(name = "apple_support", version = "1.5.0", repo_name = "build_bazel_apple_support")
+bazel_dep(name = "bazel_skylib", version = "1.3.0")
+bazel_dep(name = "rules_cc", version = "0.0.9")
+bazel_dep(name = "rules_python", version = "0.30.0")
+bazel_dep(name = "rules_shell", version = "0.2.0")
+
+# LLVM dependencies - using BCR modules with repo_name for LLVM compatibility
+bazel_dep(name = "zlib", version = "1.3.1.bcr.3", repo_name = "llvm_zlib")
+bazel_dep(name = "zstd", version = "1.5.6", repo_name = "llvm_zstd")
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python")
+python.toolchain(
+    is_default = True,
+    python_version = "3.10",
+)

WORKSPACE.bzlmod

@@ -0,0 +1,32 @@
+# Copyright 2020 The OpenXLA Authors.
+#
+# 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
+#
+#      https://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.
+
+# WORKSPACE.bzlmod for dependencies that don't support bzlmod yet (LLVM)
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+LLVM_COMMIT = "ca84f2aa3be6e46a4dccb1bec56b93f2bb3d8ef0"
+LLVM_SHA256 = "5cea44df2e0c3dcb6119c2ca5d7a900001e93ec43369ed1b58eb4ed4d4c9f9f0"
+
+http_archive(
+    name = "llvm-raw",
+    build_file_content = "# empty",
+    sha256 = LLVM_SHA256,
+    strip_prefix = "llvm-project-" + LLVM_COMMIT,
+    urls = ["https://github.com/llvm/llvm-project/archive/{commit}.tar.gz".format(commit = LLVM_COMMIT)],
+)
+
+load("@llvm-raw//utils/bazel:configure.bzl", "llvm_configure")
+
+llvm_configure(name = "llvm-project")

stablehlo/.bazelversion

@@ -1,4 +1,4 @@
-7.0.2
+7.6.1
 # Copyright 2023 The StableHLO Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");

stablehlo/MODULE.bazel

@@ -20,8 +20,15 @@
 ###############################################################################
 module(name = "stablehlo")
 
+bazel_dep(name = "apple_support", version = "1.5.0", repo_name = "build_bazel_apple_support")
 bazel_dep(name = "bazel_skylib", version = "1.3.0")
+bazel_dep(name = "rules_cc", version = "0.0.9")
 bazel_dep(name = "rules_python", version = "0.30.0")
+bazel_dep(name = "rules_shell", version = "0.2.0")
+
+# LLVM dependencies - using BCR modules with repo_name for LLVM compatibility
+bazel_dep(name = "zlib", version = "1.3.1.bcr.3", repo_name = "llvm_zlib")
+bazel_dep(name = "zstd", version = "1.5.6", repo_name = "llvm_zstd")
 
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")