[webkit-changes] [WebKit/WebKit] 97b3a2: [offlineasm] Incremental build failure when genera...

[Elliott Williams]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 97b3a2dd3db7352fa6f8738688183b07c58bc031
      https://github.com/WebKit/WebKit/commit/97b3a2dd3db7352fa6f8738688183b07c58bc031
  Author: Elliott Williams <emw at apple.com>
  Date:   2023-12-06 (Wed, 06 Dec 2023)

  Changed paths:
    M Source/JavaScriptCore/offlineasm/generate_offset_extractor.rb
    M Source/JavaScriptCore/offlineasm/generate_settings_extractor.rb

  Log Message:
  -----------
  [offlineasm] Incremental build failure when generator is interrupted
https://bugs.webkit.org/show_bug.cgi?id=265729
rdar://119079705

Reviewed by Alexey Proskuryakov.

offlineasm writes headers non-atomically, so if the script is
interrupted due to a build failure in a parallel task, it leaves a
partially-written header. The build system can't tell that this header
is incomplete, so its presence breaks subsequent rebuilds.

Fix by writing to a temporary file in the same directory (or
TARGET_TEMP_DIR in Xcode), and `rename`-ing once generation is complete.

* Source/JavaScriptCore/offlineasm/generate_offset_extractor.rb:
* Source/JavaScriptCore/offlineasm/generate_settings_extractor.rb:

Canonical link: https://commits.webkit.org/271640@main