[llvm] [Bazel] Add support for Bzlmod (PR #88927)

[Aaron Siddhartha Mondal via llvm-commits]

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@@ -0,0 +1,127 @@
+# This file is licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:local.bzl", "new_local_repository")
+load(":vulkan_sdk.bzl", "vulkan_sdk_setup")
+load(":configure.bzl", "llvm_configure", "DEFAULT_TARGETS")
+
+def _llvm_configure_extension_impl(ctx):
+    targets = []
+    patches = []
+    commit = ""
+    sha256 = ""
+
+    for module in ctx.modules:
+
+        # Aggregate targets and patches across imports.
+        for config in module.tags.configure:
+            for target in config.targets:
+                if target not in targets:
+                    targets.append(target)
+            for patch in config.patches:
+                if patch not in patches:
+                    patches.append(patch)
+
+        # Use the first nonempty commit/sha configuration, starting from the
+        # top-level import and working down to the MODULE.bazel of the
+        # llvm-project-overlay itself, which does not specify these values.
+        # This way in-tree builds will always use the current sources and not
+        # fetch the llvm repository from a hardcoded commit.
+        if module.tags.configure != [] and commit == "":
+            commit = module.tags.configure[0].commit
+            sha256 = module.tags.configure[0].sha256
+
+    if commit == "":
+        if patches != []:
+            fail("""Cannot apply patches when `commit` is unspecified. Patches
+                 would modify some unknown version of the LLVM sources, making
+                 the build irreproducible.
+                 """,
+            )
+        new_local_repository(
+            name = "llvm-raw",
+            path = "../../",
+            build_file_content = "#Empty.",
+        )
+    else:
+        http_archive(
+            name = "llvm-raw",
+            build_file_content = "# Empty.",
+            sha256 = sha256,
+            strip_prefix = "llvm-project-" + commit,
+            urls = [
+                "https://github.com/llvm/llvm-project/archive/{}.tar.gz".format(
+                    commit,
+                ),
+            ],
+            patches = patches,
+            patch_args = ["-p1"],
+        )
+
+    # Fall back to the default targets if all configurations of this extension
+    # omit the `target` attribute.
+    if targets == []:
+        targets = DEFAULT_TARGETS
+
+    llvm_configure(name = "llvm-project", targets = targets)
+
+    http_archive(
+        name = "llvm_zlib",
----------------
aaronmondal wrote:

Done.

https://github.com/llvm/llvm-project/pull/88927