[PATCH] D34984: Store token literal data in PCH. Avoids disk read on PreProc expansion.

[Vassil Vassilev via Phabricator via cfe-commits]

v.g.vassilev added a subscriber: karies.
v.g.vassilev added a comment.

What would be the best way to test this. Shall we put:

  echo '#define LITERAL 42' > HEADER.h
  
  clang++ -std=c++14 -x c++-header -o HEADER.h.pch HEADER.h
  
  chmod a-r HEADER.h
  
  echo 'void f(int); void g() { f(12); }' | clang++ -std=c++14 -Xclang
  -fno-validate-pch -include-pch HEADER.h.pch -c -Xclang -emit-llvm -o -
  -x c++ -
  # works, we see the IR
  
  echo 'void f(int); void g() { f(LITERAL); }' | clang++ -std=c++14
  -Xclang -fno-validate-pch -include-pch HEADER.h.pch -c -Xclang
  -emit-llvm -o - -x c++ -
  fatal error: cannot open file
  '/home/axel/build/tmp/clang-repro-PCH-touches-disk-for-literal/HEADER.h':
  Permission denied
  1 error generated.


Repository:
  rL LLVM

https://reviews.llvm.org/D34984