[Bazel] Use bazel_skylib paths for paths munging

[GMNGeoffrey]

Summary

We do a lot of path munging and bazel_sklyib is a pretty reasonable dep.

[GMNGeoffrey]

• Extract var and bump to latest skylib version

[jpienaar]

utils/bazel/llvm_configs/BUILD.bazel

5–10

missing space

[GMNGeoffrey]

Move space in wrong place to space in right place. Total spaces are conserved :-P

utils/bazel/WORKSPACE

 # 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(":configure.bzl", "llvm_configure")
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
 
+http_archive(
+    name = "bazel_skylib",
+    sha256 = "97e70364e9249702246c0e9444bccdc4b847bed1eb03c5a3ece4f83dfe6abc44",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+    ],
+)
+
+load(":configure.bzl", "llvm_configure")
+
 llvm_configure(
     name = "llvm-project",
     overlay_path = "llvm-project-overlay",
     src_path = "../..",
 )
 
 load(":terminfo.bzl", "llvm_terminfo_from_env")
 

 load(":vulkan_sdk.bzl", "vulkan_sdk_setup")
 
 maybe(
     vulkan_sdk_setup,
     name = "vulkan_sdk",
 )
 
 http_archive(
-    name = "bazel_skylib",
-    sha256 = "97e70364e9249702246c0e9444bccdc4b847bed1eb03c5a3ece4f83dfe6abc44",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
-        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
-    ],
-)
-
-load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")
-
-bazel_skylib_workspace()
-
-http_archive(
     name = "bazel_toolchains",
     sha256 = "1adf5db506a7e3c465a26988514cfc3971af6d5b3c2218925cd6e71ee443fc3f",
     strip_prefix = "bazel-toolchains-4.0.0",
     urls = [
         "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/releases/download/4.0.0/bazel-toolchains-4.0.0.tar.gz",
         "https://github.com/bazelbuild/bazel-toolchains/releases/download/4.0.0/bazel-toolchains-4.0.0.tar.gz",
     ],
 )
 
 load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig")
 rbe_autoconfig(name = "rbe_default")

utils/bazel/configure.bzl

 # 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
 
 """Helper macros to configure the LLVM overlay project."""
 
 load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
+load("@bazel_skylib//lib:paths.bzl", "paths")
 load(":zlib.bzl", "llvm_zlib_disable", "llvm_zlib_system")
 load(":terminfo.bzl", "llvm_terminfo_disable", "llvm_terminfo_system")
 
 # Directory of overlay files relative to WORKSPACE
 DEFAULT_OVERLAY_PATH = "llvm-project-overlay"
 
 DEFAULT_TARGETS = [
     "AArch64",
     "AMDGPU",
     "ARM",
     "BPF",
     "Hexagon",
     "Lanai",
     "NVPTX",
     "PowerPC",
     "RISCV",
     "Sparc",
     "WebAssembly",
     "X86",
 ]
 
-def _is_absolute(path):
-    """Returns `True` if `path` is an absolute path.
-
-    Args:
-      path: A path (which is a string).
-    Returns:
-      `True` if `path` is an absolute path.
-    """
-    return path.startswith("/") or (len(path) > 2 and path[1] == ":")
-
-def _join_path(a, b):
-    if _is_absolute(b):
-        return b
-    return str(a) + "/" + str(b)
-
 def _overlay_directories(repository_ctx):
-    src_workspace_path = repository_ctx.path(
+    src_workspace_path = str(repository_ctx.path(
         repository_ctx.attr.src_workspace,
-    ).dirname
+    ).dirname)
 
-    src_path = _join_path(src_workspace_path, repository_ctx.attr.src_path)
+    src_path = paths.join(src_workspace_path, repository_ctx.attr.src_path)
 
-    overlay_workspace_path = repository_ctx.path(
+    overlay_workspace_path = str(repository_ctx.path(
         repository_ctx.attr.overlay_workspace,
-    ).dirname
-    overlay_path = _join_path(
+    ).dirname)
+    overlay_path = paths.join(
         overlay_workspace_path,
         repository_ctx.attr.overlay_path,
     )
 
     overlay_script = repository_ctx.path(
         repository_ctx.attr._overlay_script,
     )
     python_bin = repository_ctx.which("python3")

utils/bazel/examples/http_archive/WORKSPACE

 # 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
 
 """An example WORKSPACE for configuring LLVM using http_archive."""
 
 workspace(name = "http_archive_example")
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
+http_archive(
+    name = "bazel_skylib",
+    sha256 = "97e70364e9249702246c0e9444bccdc4b847bed1eb03c5a3ece4f83dfe6abc44",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+    ],
+)
+
 # Replace with the LLVM commit you want to use.
 LLVM_COMMIT = "09ac97ce350316b95b8cddb796d52f71b6f68296"
 
 # The easiest way to calculate this for a new commit is to set it to empty and
 # then run a bazel build and it will report the digest necessary to cache the
 # archive and make the build reproducible.
 LLVM_SHA256 = "2fb1aa06d12f8db349a27426cb0ced062987c5c2a75143c69f4284929e2750ff"
 

utils/bazel/examples/submodule/WORKSPACE

 # 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
 
 """An example WORKSPACE for configuring LLVM using a git submodule."""
 
 workspace(name = "submodule_example")
 
+http_archive(
+    name = "bazel_skylib",
+    sha256 = "97e70364e9249702246c0e9444bccdc4b847bed1eb03c5a3ece4f83dfe6abc44",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.0.2/bazel-skylib-1.0.2.tar.gz",
+    ],
+)
+
 # Or wherever your submodule is located.
 SUBMODULE_PATH = "third_party/llvm-project"
 
 local_repository(
     name = "llvm-bazel",
     path = SUBMODULE_PATH + "/utils/bazel",
 )
 

utils/bazel/llvm-project-overlay/mlir/tblgen.bzl

 # 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
 """BUILD extensions for MLIR table generation."""
 
+load("@bazel_skylib//lib:paths.bzl", "paths")
+
+
 TdInfo = provider(
     "Holds TableGen files and the dependencies and include paths necessary to" +
     " build them.",
     fields = {
         "transitive_sources": "td files transitively used by this rule.",
         "transitive_includes": (
             "include arguments to add to the final TableGen invocation. These" +
             " are the absolute directory paths that will be added with '-I'."
def _prefix_roots(ctx, includes):
 
     This will expand them to be relative to all the root directories available
     in the execution environment for ctx.run (bin and genfiles in addition to
     the normal source root)
     """
     prefixed_includes = []
     for include in includes:
         prefixed_includes.append(include)
-        prefixed_includes.append(ctx.genfiles_dir.path + "/" + include)
-        prefixed_includes.append(ctx.bin_dir.path + "/" + include)
+        prefixed_includes.append(paths.join(ctx.genfiles_dir.path, include))
+        prefixed_includes.append(paths.join(ctx.bin_dir.path, include))
     return prefixed_includes
 
 def _resolve_includes(ctx, includes):
     """Resolves include paths to paths relative to the execution root.
 
     Relative paths are interpreted as relative to the current label's package.
     Absolute paths are interpreted as relative to the current label's workspace
     root."""
     package = ctx.label.package
     workspace_root = ctx.label.workspace_root
     workspace_root = workspace_root if workspace_root else "."
     resolved_includes = []
     for include in includes:
-        if not include.startswith("/"):
-            include = "/" + package + "/" + include
-        include = workspace_root + include
+        if paths.is_absolute(include):
+            include = include.lstrip("/")
+        else:
+            include = paths.join(package, include)
+        include = paths.join(workspace_root, include)
         resolved_includes.extend(_prefix_roots(ctx, [include]))
     return resolved_includes
 
 def _td_library_impl(ctx):
     trans_srcs = _get_transitive_srcs(ctx.files.srcs, ctx.attr.deps)
     trans_includes = _get_transitive_includes(
         _resolve_includes(ctx, ctx.attr.includes),
         ctx.attr.deps,
Args:
       td_includes: See gentbl_rule.td_includes
       deps: See gentbl_rule.deps
       test: Whether to create a shell test that invokes the tool too.
       skip_opts: Files generated using these opts in tbl_outs will be excluded
         from the generated filegroup.
       **kwargs: Extra keyword arguments to pass to all generated rules.
     """
 
-    llvm_project_execroot_path = Label("//mlir:tblgen.bzl", relative_to_caller_repository = False).workspace_root
+    llvm_project_execroot_path = Label(
+        "//mlir:tblgen.bzl",
+        relative_to_caller_repository = False,
+    ).workspace_root
 
     # TODO(gcmn): Update callers to td_library and explicit includes and drop
     # this hardcoded include.
     hardcoded_includes = [
-        "%s/mlir/include" % llvm_project_execroot_path,
+        paths.join(llvm_project_execroot_path, "mlir/include"),
     ]
 
     for (opts, out) in tbl_outs:
         first_opt = opts[0] if opts else ""
         rule_suffix = "_{}_{}".format(
             first_opt.replace("-", "_").replace("=", "_"),
             str(hash(" ".join(opts))),
         )

utils/bazel/llvm_configs/BUILD.bazel

 # 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
 
-# We perform diff testing here to avoid any in-tree BUILD files depending on
-# bazel_sklyib. These diff tests ensure that the current Bazel configuration
-# does not drift from the configuration in the .cmake files, since we don't
-# alway use them directly (and even if we did we wouldn't necessarily pick up
-# changes there). These are literal change-detector tests.
+# These diff tests ensure that the current Bazel configurationdoes not drift
+# from the configuration in the .cmake files, since we don't alway use them
+# directly (and even if we did we wouldn't necessarily pick up changes there).
+# These are literal change-detector tests.  We perform diff testing here since
+# it isn't really part of building LLVM and we don't want to include the config
+# copies in the workspace used by dependent projects.
 
 load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
 
 diff_test(
     name = "diff_config.h.cmake",
     file1 = "@llvm-project//llvm:include/llvm/Config/config.h.cmake",
     file2 = "config.h.cmake",
 )