[all-commits] [llvm/llvm-project] 8a4fcf: Remove non-affecting module maps from PCM files.

[Jan Svoboda via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8a4fcfc242a0f12e346c3d6026f2ad8764b08f1e
      https://github.com/llvm/llvm-project/commit/8a4fcfc242a0f12e346c3d6026f2ad8764b08f1e
  Author: Ilya Kuteev <ilyakuteev at yandex-team.ru>
  Date:   2021-11-18 (Thu, 18 Nov 2021)

  Changed paths:
    M clang/include/clang/Serialization/ASTWriter.h
    M clang/lib/Serialization/ASTWriter.cpp
    A clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/a.modulemap
    A clang/test/Modules/Inputs/AddRemoveIrrelevantModuleMap/b.modulemap
    A clang/test/Modules/add-remove-irrelevant-mobile-map.m
    A clang/test/SemaCXX/Inputs/compare.modulemap
    M clang/test/SemaCXX/compare-modules-cxx2a.cpp

  Log Message:
  -----------
  Remove non-affecting module maps from PCM files.

Problem:
PCM file includes references to all module maps used in compilation which created PCM. This problem leads to PCM-rebuilds in distributed compilations as some module maps could be missing in isolated compilation. (For example in our distributed build system we create a temp folder for every compilation with only modules and headers that are needed for that particular command).

Solution:
Add only affecting module map files to a PCM-file.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D106876