Modernize Bazel setup (#20)

* No longer rely on `native.bind` and the `external` package
* Replace host with exec cfg
* Use `ctx.actions.args()` instead of string lists
* Use `http_jar` instead of `jvm_maven_import_external`

Author: fmeum

jar_jar.bzl

@@ -1,6 +1,6 @@
 load(
-    "@bazel_tools//tools/build_defs/repo:jvm.bzl",
-    "jvm_maven_import_external",
+    "@bazel_tools//tools/build_defs/repo:http.bzl",
+    "http_jar",
 )
 
 def _jar_jar_impl(ctx):
@@ -16,12 +16,18 @@ def _jar_jar_impl(ctx):
             content = "\n".join(ctx.attr.inline_rules)
         )
 
+    args = ctx.actions.args()
+    args.add("process")
+    args.add(rule_file)
+    args.add(ctx.file.input_jar)
+    args.add(ctx.outputs.jar)
+
     ctx.actions.run(
         inputs = [rule_file, ctx.file.input_jar],
         outputs = [ctx.outputs.jar],
         executable = ctx.executable._jarjar_runner,
         progress_message = "jarjar %s" % ctx.label,
-        arguments = ["process", rule_file.path, ctx.file.input_jar.path, ctx.outputs.jar.path],
+        arguments = [args],
     )
 
     return [
@@ -38,41 +44,31 @@ jar_jar = rule(
         "input_jar": attr.label(allow_single_file = True),
         "rules": attr.label(allow_single_file = True),
         "inline_rules" : attr.string_list(),
-        "_jarjar_runner": attr.label(executable = True, cfg = "host", default = Label("@com_github_johnynek_bazel_jar_jar//src/main/java/com/github/johnynek/jarjar:app")),
+        "_jarjar_runner": attr.label(executable = True, cfg = "exec", default = "//src/main/java/com/github/johnynek/jarjar:app"),
     },
     outputs = {
         "jar": "%{name}.jar",
     },
     provides = [JavaInfo],
 )
 
-def _mvn_name(coord):
-    nocolon = "_".join(coord.split(":"))
-    nodot = "_".join(nocolon.split("."))
-    nodash = "_".join(nodot.split("-"))
-    return nodash
-
-def _mvn_jar(coord, sha, bname, servers):
-    nm = "jar_jar_" + _mvn_name(coord)
-    jvm_maven_import_external(
-        name = nm,
-        artifact = coord,
-        server_urls = servers,
-        artifact_sha256 = sha,
-        licenses = [],
+def _http_jar_with_servers(name, path, sha256, servers):
+    http_jar(
+      name = name,
+      urls = [server + path for server in servers],
+      sha256 = sha256,
     )
-    native.bind(name = ("com_github_johnynek_bazel_jar_jar/%s" % bname), actual = "@%s//jar" % nm)
 
-def jar_jar_repositories(servers = ["https://repo1.maven.org/maven2"]):
-    _mvn_jar(
-        "org.ow2.asm:asm:7.0",
-        "b88ef66468b3c978ad0c97fd6e90979e56155b4ac69089ba7a44e9aa7ffe9acf",
-        "asm",
-        servers,
+def jar_jar_repositories(servers=["https://repo1.maven.org/maven2"]):
+    _http_jar_with_servers(
+      name = "bazel_jar_jar_asm",
+      path = "/org/ow2/asm/asm/7.0/asm-7.0.jar",
+      sha256 = "b88ef66468b3c978ad0c97fd6e90979e56155b4ac69089ba7a44e9aa7ffe9acf",
+      servers = servers,
     )
-    _mvn_jar(
-        "org.ow2.asm:asm-commons:7.0",
-        "fed348ef05958e3e846a3ac074a12af5f7936ef3d21ce44a62c4fa08a771927d",
-        "asm_commons",
-        servers,
+    _http_jar_with_servers(
+      name = "bazel_jar_jar_asm_commons",
+      path = "/org/ow2/asm/asm-commons/7.0/asm-commons-7.0.jar",
+      sha256 = "fed348ef05958e3e846a3ac074a12af5f7936ef3d21ce44a62c4fa08a771927d",
+      servers = servers,
     )

jar_jar_toolchain.bzl

@@ -12,7 +12,7 @@ jar_jar_toolchain = rule(
     attrs = {
         "rules": attr.label(allow_single_file = True),
         "duplicate_class_to_warn": attr.bool(mandatory = False, default = False),
-        "jar_jar_runner": attr.label(executable = True, cfg = "host", default = Label("@com_github_johnynek_bazel_jar_jar//src/main/java/com/github/johnynek/jarjar:app")),
+        "jar_jar_runner": attr.label(executable = True, cfg = "exec", default = "//src/main/java/com/github/johnynek/jarjar:app"),
         "jar_jar_is_native_image": attr.bool(default = False)
     },
 )

src/main/java/com/github/johnynek/jarjar/BUILD

@@ -6,8 +6,8 @@ java_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
-        "//external:com_github_johnynek_bazel_jar_jar/asm",
-        "//external:com_github_johnynek_bazel_jar_jar/asm_commons",
+        "@bazel_jar_jar_asm//jar",
+        "@bazel_jar_jar_asm_commons//jar",
     ],
 )