| @echo off |
| :: Copyright 2017 The Chromium Authors. All rights reserved. |
| :: Use of this source code is governed by a BSD-style license that can be |
| :: found in the LICENSE file. |
| |
| setlocal |
| set PYTHON_BAT_RUNNER=1 |
| |
| :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
| :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
| :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
| :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
| :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
| |
| :: This file is automatically generated by "bootstrap\win\win_tools.py", and |
| :: should not be modified. |
| :: |
| :: The previous "::" block acts as a nop-sled. Each time a batch file executes |
| :: a command, it reloads itself and seeks to its previous execution offset to |
| :: begin execution. Updating this batch file is, therefore, risky, since any |
| :: running Python instance that is using the old batch file will reload the new |
| :: batch file once the Python command terminates and resume at some unknown |
| :: offset. |
| :: |
| :: With the sled in place, a previous instance will resume mid-label. We are |
| :: assuming that the offset of the Python invocation is greater than the |
| :: PYTHON_BAT_RUNNER set command, which is the case since the old instance has |
| :: a large PATH set block before the Python execution. Old instances will hit |
| :: the next block of code without PYTHON_BAT_RUNNER set. New instances will have |
| :: it set. |
| :: |
| :: We remedy this in the future by having the batch file load its core paths |
| :: from an external file with for/set, removing the need to modify "python.bat" |
| :: during upgrade. |
| :: |
| :: After all of the old batch files are believed to be replaced, we can remove |
| :: the PYTHON_BAT_RUNNER block and the sled. For this update, old instances |
| :: will resume past the end of the file and terminate. |
| |
| if not "%PYTHON_BAT_RUNNER%" == "1" goto :END |
| |
| for /f %%i in (%~dp0python3_bin_reldir.txt) do set PYTHON3_BIN_RELDIR=%%i |
| set PATH=%~dp0%PYTHON3_BIN_RELDIR%;%~dp0%PYTHON3_BIN_RELDIR%\Scripts;%PATH% |
| "%~dp0%PYTHON3_BIN_RELDIR%\python3.exe" %* |
| |
| :END |