To differentiate between two modules with the same name, we will
consider the path the module map file that they are defined by* part of
the ‘key’ for looking up the precompiled module (pcm file).
Specifically, this patch renames the precompiled module (pcm) files from
cache-path/<module hash>/Foo.pcm
to
cache-path/<module hash>/Foo-<hash of module map path>.pcm
In addition, I’ve taught the ASTReader to re-resolve the names of
imported modules during module loading so that if the header search
context changes between when a module was originally built and when it
is loaded we can rebuild it if necessary. For example, if module A
imports module B
first time:
clang -I /path/to/A -I /path/to/B ...
second time:
clang -I /path/to/A -I /different/path/to/B ...
will now rebuild A as expected.
* in the case of inferred modules, we use the module map file that
allowed the inference, not the __inferred_module.map file, since the
inferred file path is the same for every inferred module.
llvm-svn: 206201
Nick Lewycky