Reapply [VFS] Skip non existent files from the VFS tree

Reapply r278457 with test fixed to not abouse fs case sensitivity.

When the VFS uses a YAML file, the real file path for a
virtual file is de

Reapply [VFS] Skip non existent files from the VFS tree

Reapply r278457 with test fixed to not abouse fs case sensitivity.

When the VFS uses a YAML file, the real file path for a
virtual file is described in the "external-contents" field. Example:

...
{
'type': 'file',
'name': 'a.h',
'external-contents': '/a/b/c/a.h'
}

Currently, when parsing umbrella directories, we use
vfs::recursive_directory_iterator to gather the header files to generate the
equivalent modules for. If the external contents for a header does not exist,
we currently are unable to build a module, since the VFS
vfs::recursive_directory_iterator will fail when it finds an entry without a
reliable real path.

Since the YAML file could be prepared ahead of time and shared among
different compiler invocations, an entry might not yet have a reliable
path in 'external-contents', breaking the iteration.

Give the VFS the capability to skip such entries whenever
'ignore-non-existent-contents' property is set in the YAML file.

rdar://problem/27531549

llvm-svn: 278543

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Revert "[VFS] Skip non existent files from the VFS tree"

Breaking bots:
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/27281/

This reverts commit r278457.

llvm-svn: 278

Revert "[VFS] Skip non existent files from the VFS tree"

Breaking bots:
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/27281/

This reverts commit r278457.

llvm-svn: 278459

show more ...

[VFS] Skip non existent files from the VFS tree

When the VFS uses a YAML file, the real file path for a
virtual file is described in the "external-contents" field. Example:

...
{
'type': '

[VFS] Skip non existent files from the VFS tree

When the VFS uses a YAML file, the real file path for a
virtual file is described in the "external-contents" field. Example:

...
{
'type': 'file',
'name': 'a.h',
'external-contents': '/a/b/c/a.h'
}

Currently, when parsing umbrella directories, we use
vfs::recursive_directory_iterator to gather the header files to generate the
equivalent modules for. If the external contents for a header does not exist,
we currently are unable to build a module, since the VFS
vfs::recursive_directory_iterator will fail when it finds an entry without a
reliable real path.

Since the YAML file could be prepared ahead of time and shared among
different compiler invocations, an entry might not yet have a reliable
path in 'external-contents', breaking the iteration.

Give the VFS the capability to skip such entries whenever
'ignore-non-existent-contents' property is set in the YAML file.

rdar://problem/27531549

llvm-svn: 278457

show more ...