Difftool

This directory contains tools to compare build artifacts from two separate build invocations as a way of gauging build correctness and debugging potential problems with build systems under development.

Usage

Use of these tools requires a multistep process:

1. Build using legacy build system:

   $ m libc
   

2. Collect results to a tmp directory.

   $ ./collect.py out/combined-aosp_flame.ninja \
         out/target/product/flame/obj/libc.so \
         /tmp/legacyFiles
   

3. Build using the new build system:

   $ USE_BAZEL_ANALYSIS=1 m libc
   

4. Collect results to a tmp directory.

   $ ./collect.py out/combined-aosp_flame.ninja \
         out/target/product/flame/obj/libc.so \
         /tmp/newFiles
   

5. Run comparative analysis on the two tmp directories. (See documentation of difftool.py for exact usage.)

   $ ./difftool.py /tmp/legacyFiles \
         out/target/product/flame/obj/libc.so \
         /tmp/newFiles \
         out/target/product/flame/obj/libc.so
   

Use ./collect.py -h or ./difftool.py -h for full usage information of these subtools.