• Edward Z. Yang's avatar
    Per-component cabal_macros.h (#1893) and install paths · 90e908b8
    Edward Z. Yang authored
    
    
    This commit is a number of refactorings that I needed to do
    while fixing bugs with internal libraries support.
    
    - With internal libraries, it becomes especially clear that
      cabal_macros.h and Paths_foo.hs need to be done per-component.
      It is done!
    
      This change breaks BC in an important way: the preprocessor
      interface now takes a ComponentLocalBuildInfo along with the
      BuildInfo and LocalBuildInfo.  This means that if you implemented
      a custom preprocessor, or called 'preprocessComponent' in a custom
      Setup, you will have to make sure you pass the right
      ComponentLocalBuildInfo.  Some sub-notes:
    
        - While I was mucking about cabal_macros.h, I updated it to have
          two new macros: CURRENT_COMPONENT_ID (an alias for
          CURRENT_PACKAGE_KEY, but using modern terminology) and
          LOCAL_COMPONENT_ID (which refers to the public library; we use
          this in Cabal's test suite but it's unclear what the general
          utility of this is.  See the TODO.)
    
        - checkForeignDeps has a hack where we hardcode the
          cabal_macros.h of the main library.  If we did the foreign dep
          check for every component individually that would be better,
          but I didn't want to roll it into this patch.
    
    - The other piece I needed for internal libraries was per-component
      install directories; otherwise, internal libraries clobber each
      other.  absoluteInstallDirs now takes a ComponentId, which is used
      to determine what '$libname' expands to.  Generally, InstallPaths
      must be computed per component, c.f. #2836.  We're not TRULY
      per-component install paths, since some files are installed for
      the "per-package" InstallPaths (the one we computed for the
      library as a whole), but for libraries we have to compute
      InstallPaths for each one.
    
        - While doing this, ComponentLocalBuildInfo grew a new
          'componentId' field for non-library things.  This lets us
          treat InstallPaths expansion uniformly.
    Signed-off-by: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
    90e908b8
Register.hs 19.4 KB