1. 09 Nov, 2020 1 commit
    • Vassil Vassilev's avatar
      Enable C++ modules for CLHEP · caa0aa3b
      Vassil Vassilev authored and Lynn Garren's avatar Lynn Garren committed
      The C++ modules feature as described in https://clang.llvm.org/docs/Modules.html
      allow producing a binary header representation to avoid redundant header
      reparsing.
      
      This feature is used in ROOT's dictionary system since ROOT v6.20:
      https://github.com/root-project/root/blob/master/README/README.CXXMODULES.md
      
      CMSSW and other experiment migrate their dictionaries to use the provided by
      ROOT C++ modules support: https://github.com/cms-sw/cmssw/issues/15248
      
      Dictionaries which transiently include clhep can be further optimized by
      building a separate module for CLHEP which this MR aims for.
      
      The current patch introduces a module.modulemap file containing a mapping between
      a binary artifact (a module or a pcm file) and a set of header files. The C++
      modules are more picky on translation unit encapsulation and thus require all
      headers which a translation unit uses to be included. In addition to the
      missing include we outline a few virtual destructors to avoid pollution of .o
      files with weak virtual tables.
      
      This patch enables builds with modules via rootcling/genreflex/rootcint and
      enables compile-time module builds if configured like:
      cmake -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_CXX_FLAGS="-fmodules -Xclang -fmodules-local-submodule-visibility" ../clhep/
      
      The module.modulemap file is easy to maintain as it globs for the well-behaved
      header files and enumerates already the ones needed special treatment.
      
      Once merged we will backport this to cmssw.
      
      Conflicts:
      	Matrix/src/DiagMatrix.cc
      	Matrix/src/GenMatrix.cc
      	Matrix/src/Matrix.cc
      	Matrix/src/SymMatrix.cc
      	Matrix/src/Vector.cc
      caa0aa3b
  2. 26 Jun, 2012 1 commit
  3. 14 Jul, 2011 1 commit
  4. 12 Jul, 2011 2 commits