binary search tool: Support @file compiler arguments

Gradle passes arguments to gcc/clang by using the @file argument.
Implement expansion of this argument so that bisect_driver can analyze
all arguments being sent to the compiler.

TEST=Tested with NDK sample app

Change-Id: I1e1dae001a062c118b6d5c36e367612c9e4116b7
Reviewed-on: https://chrome-internal-review.googlesource.com/272935
Commit-Ready: Cassidy Burden <cburden@google.com>
Tested-by: Cassidy Burden <cburden@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/binary_search_tool/compiler_wrapper.py b/binary_search_tool/compiler_wrapper.py
index 42723ec0..54d5d7ea 100755
--- a/binary_search_tool/compiler_wrapper.py
+++ b/binary_search_tool/compiler_wrapper.py
@@ -15,6 +15,7 @@ https://docs.google.com/document/d/1yDgaUIa2O5w6dc3sSTe1ry-1ehKajTGJGQCbyn0fcEM
 from __future__ import print_function
 
 import os
+import shlex
 import sys
 
 import bisect_driver
@@ -25,6 +26,15 @@ DEFAULT_BISECT_DIR = os.path.expanduser('~/ANDROID_BISECT')
 BISECT_DIR = os.environ.get('BISECT_DIR') or DEFAULT_BISECT_DIR
 
 
+def ProcessArgFile(arg_file):
+  args = []
+  # Read in entire file at once and parse as if in shell
+  with open(arg_file, 'rb') as f:
+    args.extend(shlex.split(f.read()))
+
+  return args
+
+
 def Main(_):
   if not os.path.islink(sys.argv[0]):
     print("Compiler wrapper can't be called directly!")
@@ -35,6 +45,14 @@ def Main(_):
   if BISECT_STAGE not in bisect_driver.VALID_MODES:
     os.execv(WRAPPED, [WRAPPED] + sys.argv[1:])
 
+  # Handle @file argument syntax with compiler
+  for idx, _ in enumerate(execargs):
+    # @file can be nested in other @file arguments, use While to re-evaluate
+    # the first argument of the embedded file.
+    while execargs[idx][0] == '@':
+      args_in_file = ProcessArgFile(execargs[idx][1:])
+      execargs = execargs[0:idx] + args_in_file + execargs[idx + 1:]
+
   bisect_driver.bisect_driver(BISECT_STAGE, BISECT_DIR, execargs)