Kotlin: add aliases for default versions

MODULE.bazel

@@ -61,6 +61,7 @@ kotlin_extractor_deps = use_extension("//java/kotlin-extractor:deps.bzl", "kotli
 # following list can be kept in sync by running `bazel mod tidy` in `codeql`
 use_repo(
     kotlin_extractor_deps,
+    "codeql_kotlin_defaults",
     "codeql_kotlin_embeddable",
     "kotlin-compiler-1.4.32",
     "kotlin-compiler-1.5.0",

java/kotlin-extractor/BUILD.bazel

@@ -8,6 +8,7 @@ load(
 )
 load("@rules_kotlin//kotlin:jvm.bzl", "kt_jvm_library")
 load("@rules_kotlin//kotlin:core.bzl", "kt_kotlinc_options")
+load("@codeql_kotlin_defaults//:defaults.bzl", "kotlin_extractor_defaults")
 
 _for_embeddable = repo_name().endswith("codeql_kotlin_embeddable")
 
@@ -114,3 +115,41 @@ _resources = [
     )
     for v in VERSIONS
 ]
+
+# default aliases, based on the kotlinc version installed on the host
+# * default version can be overridden with env variableCODEQL_KOTLIN_SINGLE_VERSION
+# * setting CODEQL_KOTLIN_SINGLE_VERSION_EMBEDDABLE=true overrides the default variant
+# * when a new kotlinc version is installed, you'll need to either `bazel clean` or
+#   `bazel fetch --force @codeql_kotlin_defaults//:all` to refresh the default
+(
+    alias(
+        name = "%s-standalone" % _common_extractor_name_prefix,
+        actual = "%s-standalone-%s" % (
+            _common_extractor_name_prefix,
+            kotlin_extractor_defaults.version,
+        ),
+        visibility = ["//visibility:public"],
+    ),
+    alias(
+        name = "%s-embeddable" % _common_extractor_name_prefix,
+        actual = "%s-embeddable-%s" % (
+            _common_extractor_name_prefix,
+            kotlin_extractor_defaults.version,
+        ),
+        visibility = ["//visibility:public"],
+    ),
+    alias(
+        name = _common_extractor_name_prefix,
+        actual = "%s-%s-%s" % (
+            _common_extractor_name_prefix,
+            kotlin_extractor_defaults.variant,
+            kotlin_extractor_defaults.version,
+        ),
+        visibility = ["//visibility:public"],
+    ),
+    alias(
+        name = "kotlin-extractor",
+        actual = _common_extractor_name_prefix,
+        visibility = ["//visibility:public"],
+    ),
+) if not _for_embeddable else None

java/kotlin-extractor/deps.bzl

@@ -1,4 +1,4 @@
-load("//java/kotlin-extractor:versions.bzl", "VERSIONS")
+load("//java/kotlin-extractor:versions.bzl", "DEFAULT_FALLBACK_VERSION", "VERSIONS", "version_less")
 load("//misc/bazel:lfs.bzl", "lfs_smudge")
 
 _kotlin_dep_build = """
@@ -70,6 +70,41 @@ def _embeddable_source_impl(repository_ctx):
 
 _embeddable_source = repository_rule(implementation = _embeddable_source_impl)
 
+def _get_default_version(repository_ctx):
+    default_version = repository_ctx.getenv("CODEQL_KOTLIN_SINGLE_VERSION")
+    if default_version:
+        if default_version not in VERSIONS:
+            fail("overriding CODEQL_KOTLIN_SINGLE_VERSION=%s not known, must be one of:\n  %s" %
+                 (default_version, " ".join(VERSIONS)))
+        return default_version
+    kotlinc = repository_ctx.which("kotlinc")
+    if not kotlinc:
+        return DEFAULT_FALLBACK_VERSION
+    res = repository_ctx.execute([kotlinc, "-version"])
+    if not res:
+        fail("kotlinc -version failed: %s" % res.stderr)
+    out = res.stderr.split(" ")
+    if len(out) < 3:
+        fail("malformed kotlinc -version output: %s" % res.stdout)
+    host_version = out[2]
+    for version in reversed(VERSIONS):
+        if version_less(version, host_version) or version == host_version:
+            return version
+    fail("no relevant version found for host version %s among:\n  %s" % (host_version, " ".join(VERSIONS)))
+
+def _defaults_impl(repository_ctx):
+    default_version = _get_default_version(repository_ctx)
+    default_variant = "standalone"
+    if repository_ctx.getenv("CODEQL_KOTLIN_SINGLE_VERSION_EMBEDDABLE") in ("true", "1"):
+        default_variant = "embeddable"
+    repository_ctx.file(
+        "defaults.bzl",
+        "kotlin_extractor_defaults = struct(version = '%s', variant = '%s')\n" % (default_version, default_variant),
+    )
+    repository_ctx.file("BUILD.bazel")
+
+_defaults = repository_rule(implementation = _defaults_impl)
+
 def _add_rule(rules, rule, *, name, **kwargs):
     rule(name = name, **kwargs)
     rules.append(name)
@@ -80,6 +115,7 @@ def _kotlin_deps_impl(module_ctx):
         for lib in ("compiler", "compiler-embeddable", "stdlib"):
             _add_rule(deps, _kotlin_dep, name = "kotlin-%s-%s" % (lib, v))
     _add_rule(deps, _embeddable_source, name = "codeql_kotlin_embeddable")
+    _add_rule(deps, _defaults, name = "codeql_kotlin_defaults")
     return module_ctx.extension_metadata(
         root_module_direct_deps = deps,
         root_module_direct_dev_deps = [],

java/kotlin-extractor/kotlin_plugin_versions.py

@@ -62,6 +62,7 @@ def get_single_version(fakeVersionOutput = None):
         raise KotlincNotFoundException()
     versionOutput = subprocess.run([kotlinc, '-version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stderr if fakeVersionOutput is None else fakeVersionOutput
     m = re.match(r'.* kotlinc-jvm ([0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z][a-zA-Z0-9]*)?) .*', versionOutput)
+    if m is None:
     if m is None:
         raise Exception('Cannot detect version of kotlinc (got ' + str(versionOutput) + ')')
     current_version = version_string_to_version(m.group(1))
@@ -87,4 +88,3 @@ if __name__ == "__main__":
         print(get_single_version(*args[2:]))
     else:
         raise Exception("Unknown command: " + command)
-

java/kotlin-extractor/versions.bzl

@@ -16,6 +16,8 @@ VERSIONS = [
     "2.0.255-SNAPSHOT",
 ]
 
+DEFAULT_FALLBACK_VERSION = "1.9.0-Beta"
+
 def _version_to_tuple(v):
     v, _, tail = v.partition("-")
     v = tuple([int(x) for x in v.split(".")])