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diff --git a/private/rules/javadoc.bzl b/private/rules/javadoc.bzl
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index 9b90570..c9b6f09 100644
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--- a/private/rules/javadoc.bzl
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+++ b/private/rules/javadoc.bzl
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@@ -12,10 +12,43 @@ def generate_javadoc(ctx, javadoc, source_jars, classpath, javadocopts, output):
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         arguments = [args],
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     )
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+def _get_prefix_strings(third_party_prefixes):
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+    path_prefixes = []
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+    for prefix in third_party_prefixes:
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+        if prefix.find(":") != -1:
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+            fail("Target prefixes may only contain paths, not specific targets: %s" % prefix)
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+
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+        if prefix.startswith("@"):
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+            if len(prefix) > 1:
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+                path_prefixes.append("external/%s" % prefix[1:].replace("//", "/"))
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+            else:
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+                # Allow all external dependencies to be ignored
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+                path_prefixes.append("external/")
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+        elif prefix.startswith("//"):
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+            if len(prefix) < 3:
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+                fail("Prefixes for targets within this workspace must contain a path")
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+            path_prefixes.append(prefix[2:])
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+
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+    # Now we have the prefixes, ensure that they do not end with a slash
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+    return [path[:-1] if path.endswith("/") else path for path in path_prefixes]
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+
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+def _path_match(file, prefixes):
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+    short_path = file.dirname[len(file.root.path) + 1:]
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+
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+    for prefix in prefixes:
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+        if short_path.startswith(prefix):
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+            return True
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+    return False
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+
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 def _javadoc_impl(ctx):
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+    path_prefixes = _get_prefix_strings(ctx.attr.third_party_prefixes)
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     sources = []
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+
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     for dep in ctx.attr.deps:
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-        sources.extend(dep[JavaInfo].source_jars)
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+        dep_srcs = dep[JavaInfo].transitive_source_jars.to_list() if ctx.attr.transitive else dep[JavaInfo].source_jars
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+        for jar in dep_srcs:
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+            if not _path_match(jar, path_prefixes):
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+                sources.append(jar)
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     jar_file = ctx.actions.declare_file("%s.jar" % ctx.attr.name)
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@@ -41,13 +74,23 @@ javadoc = rule(
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             doc = """The java libraries to generate javadocs for.
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           The source jars of each dep will be used to generate the javadocs.
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-          Currently docs for transitive dependencies are not generated.
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+          By default docs for transitive dependencies are not generated.
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           """,
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             mandatory = True,
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             providers = [
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                 [JavaInfo],
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             ],
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         ),
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+        "transitive": attr.bool(
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+            doc = "Whether to generate docs for transitive dependencies too.",
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+            default = False,
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+        ),
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+        "third_party_prefixes": attr.string_list(
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+            doc = """Label prefixes to exclude from javadoc generation. This designed
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+            to allow merging of all first party javadocs into a single jar whilst not
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+            including any javadocs for third party packages the code may depend on.""",
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+            default = ["@maven//"],
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+        ),
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         "javadocopts": attr.string_list(
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             doc = """javadoc options.
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             Note sources and classpath are derived from the deps. Any additional
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