Commit Graph

3 Commits

Author SHA1 Message Date
Rui Ueyama 5c33bbed58 Replace -flavor {gnu,darwin} with ld64.lld or ld.lld.
llvm-svn: 325390
2018-02-16 21:16:57 +00:00
Nick Kledzik a721db24c0 Subclass InputGraph to get darwin linker library semantics
The darwin linker operates differently than the gnu linker with respect to
libraries. The darwin linker first links in all object files from the command
line, then to resolve any remaining undefines, it repeatedly iterates over
libraries on the command line until either all undefines are resolved or no
undefines were resolved in the last pass.

When Shankar made the InputGraph model, the plan for darwin was for the darwin
driver to place all libraries in a group at the end of the InputGraph. Thus
making the darwin model a subset of the gnu model. But it turns out that does
not work because the driver cannot tell if a file is an object or library until
it has been loaded, which happens later.

This solution is to subclass InputGraph for darwin and just iterate the graph
the way darwin linker needs.

llvm-svn: 220330
2014-10-21 21:14:11 +00:00
Tim Northover 77d82202d1 [mach-o]: support -syslibroot and -l options
These behave slightly idiosyncratically in the best of cases, and have
additional hacks layered on top of that for compatibility with badly behaved
build systems (via ld64).

For -lXYZ:
  + If XYZ is actually XY.o then search all library paths for XY.o
  + Otherwise search all library paths, first for libXYZ.dylib, then libXYZ.a
  + By default the library paths are /usr/lib and /usr/local/lib in that order.

For -syslibroot:
  + -syslibroot options apply to absolute paths in the search order.
  + All -syslibroot prefixes that exist are added to the search path *instead*
    of the original.
  + If no -syslibroot prefixed path exists, the original is kept.
  + Hacks^WExceptions:
      + If only 1 -syslibroot is given and doesn't contain /usr/lib or
        /usr/local/lib, that path is dropped entirely. (rdar://problem/6438270).
      + If the last -syslibroot is "/", all of them are ignored entirely.
        (rdar://problem/5829579).

At least, that's my best interpretation of what ld64 does in buildSearchPaths.

llvm-svn: 212706
2014-07-10 11:21:06 +00:00