Allow building from head repo (bazelbuild#612)

Author: restingbull

README.md

@@ -178,21 +178,49 @@ Third party (external) artifacts can be brought in with systems such as [`rules_
 # Development Setup Guide
 As of 1.5.0, to use the rules directly from the rules_kotlin workspace (i.e. not the release artifact)
  require the use of `release_archive` repository. This repository will build and configure the current
- workspace to use `rules_kotlin` in the same manner as the released binary artifact.
+workspace to use `rules_kotlin` in the same manner as the released binary artifact.
 
 In the project's `WORKSPACE`, change the setup:
+
 ```python
 
 # Use local check-out of repo rules (or a commit-archive from github via http_archive or git_repository)
 local_repository(
     name = "release_archive",
     path = "../path/to/rules_kotlin_clone/src/main/starlark/release_archive",
 )
-
 load("@release_archive//:repository.bzl", "archive_repository")
 
+
+archive_repository(
+    name = "io_bazel_rules_kotlin",
+)
+
+load("@io_bazel_rules_kotlin//kotlin:repositories.bzl", "kotlin_repositories", "versions")
+
+kotlin_repositories()
+
+load("@io_bazel_rules_kotlin//kotlin:core.bzl", "kt_register_toolchains")
+
+kt_register_toolchains()
+```
+
+To use rules_kotlin from head without cloning the repository, (caveat emptor, of course), change the
+rules to this:
+
+```python
+# Download master or specific revisions
+http_archive(
+    name = "io_bazel_rules_kotlin_master",
+    urls = [ "https://github.com/bazelbuild/rules_kotlin/archive/refs/heads/master.zip", ],
+    strip_prefix = "rules_kotlin-master",
+)
+
+load("@io_bazel_rules_kotlin_master//src/main/starklark/release_archive", "archive_repository")
+
 archive_repository(
     name = "io_bazel_rules_kotlin",
+    source_repository_name = "io_bazel_rules_kotlin_master"
 )
 
 load("@io_bazel_rules_kotlin//kotlin:repositories.bzl", "kotlin_repositories", "versions")

WORKSPACE

@@ -0,0 +1 @@
+WORKSPACE.dev.bazel

WORKSPACE

@@ -0,0 +1,32 @@
+# Copyright 2018 The Bazel Authors. All rights reserved.
+#
+# 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
+#
+#    http://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(name = "dev_io_bazel_rules_kotlin")
+
+load("//src/main/starlark/core/repositories:download.bzl", "kt_download_local_dev_dependencies")
+
+kt_download_local_dev_dependencies()
+
+load("//kotlin:repositories.bzl", "kotlin_repositories")
+
+kotlin_repositories()
+
+register_toolchains("@dev_io_bazel_rules_kotlin//kotlin/internal:default_toolchain")
+
+# Creates toolchain configuration for remote execution with BuildKite CI
+# for rbe_ubuntu1604
+load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig")
+
+rbe_autoconfig(
+    name = "buildkite_config",
+)

WORKSPACE.dev.bazel

@@ -50,6 +50,7 @@ def kt_configure():
         ],
         repositories = [
             "https://maven-central.storage.googleapis.com/repos/central/data/",
+            "https://maven.google.com",
             "https://repo1.maven.org/maven2",
         ],
     )

src/main/starlark/core/repositories/setup.bzl

@@ -1,3 +1,6 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
+
 versions = struct(
     RULES_KOTLIN = struct(
         urls = [
@@ -6,6 +9,13 @@ versions = struct(
         sha256 = "d8650bb939d87a080448ffbbbd1594f5ae054738df5d9471941c18784aa139b9",
         prefix = "rules_kotlin-1.5.0-beta-3",
     ),
+    RULES_KOTLIN_HEAD = struct(
+        urls = [
+            "https://github.com/bazelbuild/rules_kotlin/archive/refs/heads/master.zip",
+        ],
+        sha256 = "cd5388f019d856ede82dd2a3dc7cf935d4925340fee56094f1e23d93a62b5439",
+        prefix = "rules_kotlin-master",
+    ),
 )
 
 def archive_repository_implementation(repository_ctx):
@@ -38,10 +48,31 @@ def archive_repository_implementation(repository_ctx):
         # move to execroot, then reference local repo.
         workspace = repository_ctx.path("../../%s" % release_archive.workspace_root)
 
+        if not workspace.exists:
+            fail("local workspace %s does not exist" % workspace)
+
         target = "//%s:%s" % (release_archive.package, release_archive.name)
 
+        workspace_file = workspace.get_child("WORKSPACE")
+
+        # if kt_download_local_dev_dependencies isn't there, the WORKSPACE file is invalid
+        # probably generated by http_archive.
+        if not ("kt_download_local_dev_dependencies" in repository_ctx.read(workspace_file)):
+            repository_ctx.report_progress(
+                "Symlinking WORKSPACE to WORKSPACE.dev.bazel in %s" % (workspace.basename),
+            )
+
+            # Remove existing WORKSPACE, as it might be created by http_archive
+            repository_ctx.delete(workspace_file)
+
+            # Symlink the WORKSPACE
+            repository_ctx.symlink(
+                workspace.get_child("WORKSPACE.dev.bazel"),
+                workspace_file,
+            )
+
         repository_ctx.report_progress(
-            "Building %s in %s... (may take a while.)" % (target, workspace),
+            "Building %s in %s... (may take a while.)" % (target, workspace.basename),
         )
 
         result = repository_ctx.execute(
@@ -66,10 +97,12 @@ def archive_repository_implementation(repository_ctx):
         )
 
         # update release when the contents change.
-        return [
-            repository_ctx.path("../../%s" % release_archive.workspace_root),
-        ]
-    return []
+        return {
+            "release_archive": str(workspace),
+        }
+    return {
+        "release_archive": "",
+    }
 
 # not windows compatible.
 def _find_workspace(attr, environ, path):
@@ -99,7 +132,6 @@ _archive_repository = repository_rule(
         ),
         "local_release_archive_target": attr.label(
             doc = "release_archive rule.",
-            default = Label("@rules_kotlin_release//:rules_kotlin_release"),
         ),
         "env_archive": attr.string(
             doc = "release archive path environment variable name",
@@ -116,17 +148,46 @@ _archive_repository = repository_rule(
     },
 )
 
-def archive_repository(name, local_path = "../..", release_archive_target = Label("//:rules_kotlin_release")):
-    release_name = "%s_head" % name
-    if not native.existing_rule(release_name):
-        native.local_repository(
-            name = release_name,
+def archive_repository(
+        name,
+        local_path = "../..",
+        release_archive_target = Label("//:rules_kotlin_release"),
+        remote_source_archive = None,
+        source_repository_name = None):
+    """
+    archive_repository builds rules_kotlin from either a local_path or a remote archive.
+
+    Args:
+        name: of the repository
+        local_path: to an un-archived rules_kotlin repository. Defaults to '../..'.
+        release_archive_target: Label to build a rules_kotlin release
+        remote_source_archive: struct(
+            urls = list of urls for a remote source archive,
+            sha256 = hash of remote archive,
+            prefix = directory string to strip from extracted archive
+        )
+        source_repository_name: of the release archive. Defaults to `name`_head. If set to an existing
+          repository no new repository will be created.
+    """
+    source_repository_name = source_repository_name or ("%s_head" % name)
+    if remote_source_archive:
+        maybe(
+            http_archive,
+            name = source_repository_name,
+            sha256 = remote_source_archive.sha256,
+            strip_prefix = remote_source_archive.prefix,
+            urls = remote_source_archive.urls,
+        )
+    else:
+        maybe(
+            native.local_repository,
+            name = source_repository_name,
             path = local_path,
         )
     _archive_repository(
         name = name,
         local_release_archive_target = "@%s//%s:%s" % (
-            release_name,
+            source_repository_name,
             release_archive_target.package,
             release_archive_target.name,
         ),