Windows,Android: support long paths in tool

//tools/android/aar_embedded_jars_extractor.py now
supports long paths using the same
junction-creating trick as aar_resources_extractor
does.

Fixes https://github.com/bazelbuild/bazel/issues/3808

Change-Id: I2db25b0536ac3a97f4a04191bc398eb236923a7c
PiperOrigin-RevId: 170193093

tools/android/BUILD

diff --git a/tools/android/BUILD b/tools/android/BUILD
index 340847e..302fa60 100644
--- a/tools/android/BUILD
+++ b/tools/android/BUILD
@@ -123,7 +123,10 @@
 py_binary(
     name = "aar_embedded_jars_extractor",
     srcs = ["aar_embedded_jars_extractor.py"],
-    deps = ["//third_party/py/gflags"],
+    deps = [
+        ":junction_lib",
+        "//third_party/py/gflags",
+    ],
 )
 
 py_test(

tools/android/BUILD.tools

diff --git a/tools/android/BUILD.tools b/tools/android/BUILD.tools
index 7110448..1a6a6d5 100644
--- a/tools/android/BUILD.tools
+++ b/tools/android/BUILD.tools
@@ -183,7 +183,10 @@
 py_binary(
     name = "aar_embedded_jars_extractor",
     srcs = ["aar_embedded_jars_extractor.py"],
-    deps = ["//third_party/py/gflags"],
+    deps = [
+        ":junction_lib",
+        "//third_party/py/gflags",
+    ],
 )
 
 py_binary(

tools/android/aar_embedded_jars_extractor.py

diff --git a/tools/android/aar_embedded_jars_extractor.py b/tools/android/aar_embedded_jars_extractor.py
index fcdc301..a46dd43b 100644
--- a/tools/android/aar_embedded_jars_extractor.py
+++ b/tools/android/aar_embedded_jars_extractor.py
@@ -19,10 +19,12 @@
 of the jars and creates a param file for singlejar to merge them into one jar.
 """
 
+import os
 import re
 import sys
 import zipfile
 
+from tools.android import junction
 from third_party.py import gflags
 
 FLAGS = gflags.FLAGS
@@ -36,20 +38,54 @@
 gflags.MarkFlagAsRequired("output_dir")
 
 
-def ExtractEmbeddedJars(aar, singlejar_param_file, output_dir):
+def ExtractEmbeddedJars(aar,
+                        singlejar_param_file,
+                        output_dir,
+                        output_dir_orig=None):
+  if not output_dir_orig:
+    output_dir_orig = output_dir
   jar_pattern = re.compile("^(classes|libs/.+)\\.jar$")
   singlejar_param_file.write("--exclude_build_data\n")
   for name in aar.namelist():
     if jar_pattern.match(name):
       singlejar_param_file.write("--sources\n")
-      singlejar_param_file.write(output_dir + "/" + name + "\n")
+      # output_dir may be a temporary junction, so write the original
+      # (unshortened) path to the params file
+      singlejar_param_file.write(output_dir_orig + "/" + name + "\n")
       aar.extract(name, output_dir)
 
 
+def _Main(input_aar,
+          output_singlejar_param_file,
+          output_dir,
+          output_dir_orig=None):
+  if not output_dir_orig:
+    output_dir_orig = output_dir
+  with zipfile.ZipFile(input_aar, "r") as aar:
+    with open(output_singlejar_param_file, "wb") as singlejar_param_file:
+      ExtractEmbeddedJars(aar, singlejar_param_file, output_dir,
+                          output_dir_orig)
+
+
 def main():
-  with zipfile.ZipFile(FLAGS.input_aar, "r") as aar:
-    with open(FLAGS.output_singlejar_param_file, "wb") as singlejar_param_file:
-      ExtractEmbeddedJars(aar, singlejar_param_file, FLAGS.output_dir)
+  if os.name == "nt":
+    # Shorten paths unconditionally, because the extracted paths in
+    # ExtractEmbeddedJars (which we cannot yet predict, because they depend on
+    # the names of the Zip entries) may be longer than MAX_PATH.
+    aar_long = os.path.abspath(FLAGS.input_aar)
+    params_long = os.path.abspath(FLAGS.output_singlejar_param_file)
+    out_long = os.path.abspath(FLAGS.output_dir)
+    with junction.TempJunction(os.path.dirname(aar_long)) as aar_junc:
+      with junction.TempJunction(os.path.dirname(params_long)) as params_junc:
+        with junction.TempJunction(os.path.dirname(out_long)) as out_junc:
+          _Main(
+              os.path.join(aar_junc, os.path.basename(aar_long)),
+              os.path.join(params_junc, os.path.basename(params_long)),
+              os.path.join(out_junc, os.path.basename(out_long)),
+              FLAGS.output_dir)
+  else:
+    _Main(FLAGS.input_aar, FLAGS.output_singlejar_param_file, FLAGS.output_dir)
+
 
 if __name__ == "__main__":
   FLAGS(sys.argv)