commit fc60b3cc4dca8e952ead56158310e9bac23d9a34
author Googler <noreply@google.com> Mon Feb 04 07:35:41 2019 -0800
committer Copybara-Service <copybara-piper@google.com> Mon Feb 04 07:37:48 2019 -0800
tree 50762d5dc6d5d16982f7f9a4dca6b1e20a7dfbb3
parent 40c2c7b7e56a3283f20d9b4d880e9d9605dd9476

j2objc_dead_code_pruner.py: Improve the message of the exception raised when subprocess.check_output() fails in PruneArchiveFile().

Before this change, if check_output() raised OSError it would not contain information about the command that was attempted to be executed, adding to difficulty diagnosing the root cause of such an OSError.  With this change, the exception's message will include the command that was executed.

RELNOTES: None
PiperOrigin-RevId: 232294150

tools/objc/j2objc_dead_code_pruner.py

diff --git a/tools/objc/j2objc_dead_code_pruner.py b/tools/objc/j2objc_dead_code_pruner.py
index 1ec9f95..f386206 100755
--- a/tools/objc/j2objc_dead_code_pruner.py
+++ b/tools/objc/j2objc_dead_code_pruner.py
@@ -399,8 +399,12 @@
     j2objc_cmd = 'cp %s %s' % (pipes.quote(input_archive),
                                pipes.quote(output_archive))
 
-  subprocess.check_output(
-      j2objc_cmd, stderr=subprocess.STDOUT, shell=True, env=cmd_env)
+  try:
+    subprocess.check_output(
+        j2objc_cmd, stderr=subprocess.STDOUT, shell=True, env=cmd_env)
+  except OSError as e:
+    raise Exception(
+        'executing command failed: %s (%s)' % (j2objc_cmd, e.strerror))
 
   # "Touch" the output file.
   # Prevents a pre-Xcode-8 bug in which passing zero-date archive files to ld