3627 Commits

Author SHA1 Message Date
Bruno Cardoso Lopes
f08417904d [CrashReproducer] Change module map callback signature. NFC
Use a StringRef instead of a FileEntry in the moduleMapAddHeader
callback to allow more flexibility on what to collect on further
patches. This changes the interface I introduced in r264971.

llvm-svn: 268819
2016-05-06 23:21:50 +00:00
Saleem Abdulrasool
de87e5f875 Frontend: support -I=path for sysroot expansion
From the GCC manpage:

  -I dir
    ... If dir begins with =, then the = will be replaced by the sysroot prefix;
    see --sysroot and -isysroot.

Add support to expand the `=` as a prefix of the include path with the sysroot
if specified.  `-isysroot` takes precedence over `--sysroot` as the normal
argument behaviour occurs.  The ordering of the `-isysroot` is relevant to the
path substituted.  If no `--sysroot=` or `-isysroot` option is present, the = is
not expanded.

Resolves PR26965!

llvm-svn: 268777
2016-05-06 19:13:55 +00:00
Marcin Koscielnicki
b31ee6db11 [SystemZ] Add -mbackchain option.
This option, like the corresponding gcc option, is SystemZ-specific and
enables storing frame backchain links, as specified in the ABI.

Differential Revision: http://reviews.llvm.org/D19891

llvm-svn: 268575
2016-05-04 23:37:40 +00:00
Marianne Mailhot-Sarrasin
21ac3bfc69 Do not disable completely loop unroll when optimizing for size.
Let the loop unroll pass handle /Os. It already checks that option and adjust its thresholds accordingly. Also, will allow the #pragma unroll to have an effect in /Os.

Differential Revision: http://reviews.llvm.org/D19827

llvm-svn: 268509
2016-05-04 15:26:28 +00:00
Reid Kleckner
8195f696e4 [X86] Add -malign-double support
The -malign-double flag causes i64 and f64 types to have alignment 8
instead of 4. On x86-64, the behavior of -malign-double is enabled by default.

Rebases and cleans phosek's work here: http://reviews.llvm.org/D12860

Patch by Sean Klein

Reviewers: rnk

Subscribers: rnk, jfb, dschuff, phosek

Differential Revision: http://reviews.llvm.org/D19734

llvm-svn: 268473
2016-05-04 02:58:24 +00:00
Justin Lebar
76945b2f44 [CUDA] Copy host builtin types to NVPTXTargetInfo.
Summary:
Host and device types must match, otherwise when we pass values back and
forth between the host and device, we will get the wrong result.

This patch makes NVPTXTargetInfo inherit most of its type information
from the host's target info.

Reviewers: rsmith

Subscribers: cfe-commits, jhen, tra

Differential Revision: http://reviews.llvm.org/D19346

llvm-svn: 268131
2016-04-29 23:05:19 +00:00
Richard Smith
41e6629100 Fix use of uninitialized value exposed by r267802. Accessors of an invalid
PresumedLoc should not be called.

llvm-svn: 267914
2016-04-28 18:26:32 +00:00
Peter Collingbourne
3afb266886 Re-apply r267784, r267824 and r267830.
I have updated the compiler-rt tests.

llvm-svn: 267903
2016-04-28 17:09:37 +00:00
Benjamin Kramer
5556a5cf3b Revert r267784, r267824 and r267830.
It makes compiler-rt tests fail if the gold plugin is enabled.

Revert "Rework interface for bitset-using features to use a notion of LTO visibility."
Revert "Driver: only produce CFI -fvisibility= error when compiling."
Revert "clang/test/CodeGenCXX/cfi-blacklist.cpp: Exclude ms targets. They would be non-cfi."

llvm-svn: 267871
2016-04-28 12:14:47 +00:00
Peter Collingbourne
a8b2f7c0d7 Rework interface for bitset-using features to use a notion of LTO visibility.
Bitsets, and the compiler features they rely on (vtable opt, CFI),
only have visibility within the LTO'd part of the linkage unit. Therefore,
only enable these features for classes with hidden LTO visibility. This
notion is based on object file visibility or (on Windows)
dllimport/dllexport attributes.

We provide the [[clang::lto_visibility_public]] attribute to override the
compiler's LTO visibility inference in cases where the class is defined
in the non-LTO'd part of the linkage unit, or where the ABI supports
calling classes derived from abstract base classes with hidden visibility
in other linkage units (e.g. COM on Windows).

If the cross-DSO CFI mode is enabled, bitset checks are emitted even for
classes with public LTO visibility, as that mode uses a separate mechanism
to cause bitsets to be exported.

This mechanism replaces the whole-program-vtables blacklist, so remove the
-fwhole-program-vtables-blacklist flag.

Because __declspec(uuid()) now implies [[clang::lto_visibility_public]], the
support for the special attr:uuid blacklist entry is removed.

Differential Revision: http://reviews.llvm.org/D18635

llvm-svn: 267784
2016-04-27 20:39:53 +00:00
Sunil Srivastava
bf01080672 Set the default C standard to C99 when targeting the PS4.
Patch by Douglas Yung!

Differential Revision: http://reviews.llvm.org/D19003

llvm-svn: 267772
2016-04-27 19:53:03 +00:00
Yaxun Liu
382d355359 [OpenCL] Add predefined macros.
OpenCL spec requires __OPENCL_C_VERSION__ to be defined based on -cl-std option. This patch implements that.

The patch also defines __FAST_RELAXED_MATH__ based on -cl-fast-relaxed-math option.

Also fixed a test using -std=c99 for OpenCL program. Limit allowed language standard of OpenCL to be OpenCL standards.

Differential Revision: http://reviews.llvm.org/D19071

llvm-svn: 267590
2016-04-26 19:25:46 +00:00
Craig Topper
0da2076ba1 Fix a couple assertions that can never fire because the condition ANDed with the string is just true or 1.
llvm-svn: 267313
2016-04-24 02:08:22 +00:00
Bruno Cardoso Lopes
fc8644cd62 [CrashReproducer] Setup 'use-external-names' in YAML files.
Hide the real paths when rebuilding from VFS by setting up the crash
reproducer to use 'use-external-names' = false. This way we avoid
module redifinition errors and consistently use the same paths against
all modules.

With this change on Darwin we are able to simulate a crash for a simple
application using "Foundation/Foundation.h" (which relies on a bunch of
different frameworks and headers) and successfully rebuild all the
modules by relying solely at the VFS overlay.

llvm-svn: 266234
2016-04-13 19:28:21 +00:00
Wei Mi
811ff92e1e Always have clang pass -pie-level and -pic-level values to the code generator.
Patch by tmsriram!

Differential Revision: http://reviews.llvm.org/D18843

llvm-svn: 265816
2016-04-08 17:42:32 +00:00
Saleem Abdulrasool
f7b3d6c55b Move EABIVersion from CodeGenOptions to TargetOptions
It is possible to argue that the EABIVersion field is similar in spirit to the
ABI field in TargetOptions.  It represents the embedded ABI that the target
follows.  This will allow us to thread this information into the target
information construction.

llvm-svn: 265807
2016-04-08 16:52:05 +00:00
Saleem Abdulrasool
10a4972a8d revert SVN r265702, r265640
Revert the two changes to thread CodeGenOptions into the TargetInfo allocation
and to fix the layering violation by moving CodeGenOptions into Basic.
Code Generation is arguably not particularly "basic".  This addresses Richard's
post-commit review comments.  This change purely does the mechanical revert and
will be followed up with an alternate approach to thread the desired information
into TargetInfo.

llvm-svn: 265806
2016-04-08 16:52:00 +00:00
Richard Smith
6a6747d9dd [modules] Add a comment to explain why -E leaves some #includes in the preprocessed output.
llvm-svn: 265766
2016-04-08 01:23:59 +00:00
Richard Smith
466a15ef7f [modules] Don't write @import in -E output if the current language mode doesn't
support @import; use the form as written instead.

llvm-svn: 265756
2016-04-08 00:09:53 +00:00
Richard Smith
351241c83e Replace Sema-level implementation of -fassume-sane-operator-new with a
CodeGen-level implementation. Instead of adding an attribute to clang's
FunctionDecl, add the IR attribute directly. This means a module built with
this flag is now compatible with code built without it and vice versa.

This change also results in the 'noalias' attribute no longer being added to
calls to operator new in the IR; it's now only added to the declaration. It
also fixes a bug where we failed to add the attribute to the 'nothrow' versions
(because we didn't implicitly declare them, there was no good time to inject a
fake attribute).

llvm-svn: 265728
2016-04-07 21:46:12 +00:00
Saleem Abdulrasool
94cfc603d1 Basic: move CodeGenOptions from Frontend
This is a mechanical move of CodeGenOptions from libFrontend to libBasic.  This
fixes the layering violation introduced earlier by threading CodeGenOptions into
TargetInfo.  It should also fix the modules based self-hosting builds.  NFC.

llvm-svn: 265702
2016-04-07 17:49:44 +00:00
Saleem Abdulrasool
724275ba5f Basic: thread CodeGenOptions into TargetInfo
This threads CodeGenOptions into the TargetInfo hierarchy.  This is motivated by
ARM which can change some target information based on the EABI selected
(-meabi).  Similar options exist for other platforms (e.g. MIPS) and thus is
generally useful.  NFC.

llvm-svn: 265640
2016-04-07 05:41:11 +00:00
Sean Silva
72af472523 Don't use PATH_MAX.
This is a SmallVector anyway, and so the exact size doesn't matter.

clang\lib\Frontend\ModuleDependencyCollector.cpp(83) : error C2065: 'PATH_MAX' : undeclared identifier
clang\lib\Frontend\ModuleDependencyCollector.cpp(83) : error C2975: 'InternalLen' : invalid template argument for 'llvm::SmallString', expected compile-time constant expression
        llvm\include\llvm/ADT/SmallString.h(24) : see declaration of 'InternalLen'

llvm-svn: 265634
2016-04-07 01:58:14 +00:00
Bruno Cardoso Lopes
4775fcfa4e [CrashReproducer] Use toUppercase from include/clang/Basic/CharInfo.h
Use toUppercase instead of ::toupper()

llvm-svn: 265632
2016-04-07 01:12:18 +00:00
Bruno Cardoso Lopes
49acebea07 [CrashReproducer] Change std::toupper to ::toupper
Attempt to fix windows bots

llvm-svn: 265630
2016-04-07 01:04:09 +00:00
Bruno Cardoso Lopes
4c20bef1ef [CrashReproducer] Setup 'case-sensitive' in YAML files.
The crash reproducer was not setting up case sensitivity in the
VFS yaml files, which defaults to true. Make the crash reproducer
explicitly set that flag based on the case sensitivity of the .cache
path where vfs and modules are dumped.

llvm-svn: 265622
2016-04-07 00:00:57 +00:00
Bruno Cardoso Lopes
7caebc182a [CrashReproducer] Move ModuleDependencyCollector method around. NFC
llvm-svn: 265621
2016-04-07 00:00:42 +00:00
Sean Silva
31994e2eb6 Revert "Set the default C standard to C99 when targeting the PS4."
This reverts r265359.

It breaks
- llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast
- llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast

Failing Tests (5):
    Clang :: FixIt/fixit-errors.c
    Clang :: Preprocessor/init.c
    Clang :: Sema/attr-deprecated.c
    Clang :: Sema/nullability.c
    Clang :: SemaObjC/objcbridge-attribute-arc.m

llvm-svn: 265601
2016-04-06 21:06:52 +00:00
Dmitry Polukhin
0b0da296e6 [OPENMP] Parsing and Sema support for 'omp declare target' directive
Add parsing, sema analysis for 'declare target' construct for OpenMP 4.0
(4.5 support will be added in separate patch).

The declare target directive specifies that variables, functions (C, C++
and Fortran), and subroutines (Fortran) are mapped to a device. The declare
target directive is a declarative directive. In Clang declare target is
implemented as implicit attribute for the declaration.

The syntax of the declare target directive is as follows:

 #pragma omp declare target
 declarations-definition-seq
 #pragma omp end declare target

Based on patch from Michael Wong http://reviews.llvm.org/D15321

llvm-svn: 265530
2016-04-06 11:38:59 +00:00
Justin Lebar
d3a44f6885 [CUDA] Add -fcuda-flush-denormals-to-zero.
Summary:
Setting this flag causes all functions are annotated with the
"nvvm-f32ftz" = "true" attribute.

In addition, we annotate the module with "nvvm-reflect-ftz" set
to 0 or 1, depending on whether -cuda-flush-denormals-to-zero is set.
This is read by the NVVMReflect pass.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18671

llvm-svn: 265435
2016-04-05 18:26:20 +00:00
Nirav Dave
d2f44d8de0 Add -fno-jump-tables and-fjump-tables flags
Add no-jump-tables flag to disable use of jump tables when lowering
switch statements

Reviewers: echristo, hans

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18407

llvm-svn: 265425
2016-04-05 17:50:43 +00:00
Sunil Srivastava
0e15a77d40 Set the default C standard to C99 when targeting the PS4.
Patch by Douglas Yung!

Differential Revision: http://reviews.llvm.org/D18708

llvm-svn: 265359
2016-04-04 22:56:05 +00:00
Bruno Cardoso Lopes
e62cfd7c17 [CrashReproducer] Add a module map callback for added headers
The current ModuleDependencyCollector has a AST listener to collect
header files present in loaded modules, but this isn't enough to collect
all headers needed in the crash reproducer. One of the reasons is that
the AST writer doesn't write symbolic link header paths in the pcm modules,
this makes the listeners on the reader only able to collect the real files.

Since the module maps could contain submodules that use headers which
are symbolic links, not collecting those forbid the reproducer scripts
to regen the modules.

For instance:

usr/include/module.map:
  ...
  module pthread {
    header "pthread.h"
    export *

    module impl {
      header "pthread_impl.h"
      export *
    }
  }
  ...

usr/include/pthread/pthread_impl.h
usr/include/pthread_impl.h -> pthread/pthread_impl.h

The AST dump for the module above:

  <SUBMODULE_HEADER abbrevid=6/> blob data = 'pthread_impl.h'
  <SUBMODULE_TOPHEADER abbrevid=7/> blob data = '/<path_to_sdk>/usr/include/pthread/pthread_impl.h'

Note that we don't have "usr/include/pthread_impl.h" which is requested
by the module.map in case we want to reconstruct the module in the
reproducer. The reason the original symbolic link path isn't used is
because the headers are kept by name and requested through the
FileManager, which unique files and returns the real path only.

To fix that, add a callback to be invoked everytime a header is added
while parsing module maps and hook that up to the module dependecy
collector. This callback is only registered when generating the
reproducer.

Differential Revision: http://reviews.llvm.org/D18585

rdar://problem/24499339

llvm-svn: 264971
2016-03-30 23:54:25 +00:00
Justin Lebar
ba122ab42f [CUDA] Make unattributed constexpr functions implicitly host+device.
With this patch, by a constexpr function is implicitly host+device
unless:

 a) it's a variadic function (variadic functions are not allowed on the
    device side), or
 b) it's preceeded by a __device__ overload in a system header.

The restriction on overloading __host__ __device__ functions on the
basis of their CUDA attributes remains in place, but we use (b) to allow
us to define __device__ overloads for constexpr functions in cmath,
which would otherwise be __host__ __device__ and thus not overloadable.

You can disable this behavior with -fno-cuda-host-device-constexpr.

Reviewers: tra, rnk, rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18380

llvm-svn: 264964
2016-03-30 23:30:21 +00:00
Stephan Bergmann
17d7d14571 For MS ABI, emit dllexport friend functions defined inline in class
...as that is apparently what MSVC does.  This is an updated version of r263738,
which had to be reverted in r263740 due to test failures.  The original version
had erroneously emitted functions that are defined in class templates, too (see
the updated "Handle friend functions" code in EmitDeferredDecls,
lib/CodeGen/ModuleBuilder.cpp).  (The updated tests needed to be split out into
their own dllexport-ms-friend.cpp because of the CHECK-NOTs which would have
interfered with subsequent CHECK-DAGs in dllexport.cpp.)

Differential Revision: http://reviews.llvm.org/D18430

llvm-svn: 264841
2016-03-30 06:27:31 +00:00
Bruno Cardoso Lopes
b1631d9161 [CrashReproducer] Cleanup and move functionality around in ModuleDependencyCollector. NFC
- Make ModuleDependencyCollector use the DependencyCollector interface
- Move some methods from ModuleDependencyListener to ModuleDependencyCollector
in order to share common functionality with other future possible
callbacks.

llvm-svn: 264808
2016-03-29 23:47:40 +00:00
Justin Lebar
25c4a81e79 [CUDA] Remove three obsolete CUDA cc1 flags.
Summary:
* -fcuda-target-overloads

  Previously unconditionally set to true by the driver.  Necessary for
  correct functioning of the compiler -- our CUDA headers wrapper won't
  compile without this.

* -fcuda-disable-target-call-checks

  Previously unconditionally set to true by the driver.  Necessary to
  compile almost any external CUDA code -- almost all libraries assume
  that host+device code can call host or device functions.

* -fcuda-allow-host-calls-from-host-device

  No effect when target overloading is enabled.

Reviewers: tra

Subscribers: rsmith, cfe-commits

Differential Revision: http://reviews.llvm.org/D18416

llvm-svn: 264739
2016-03-29 16:24:16 +00:00
Richard Smith
26b8f78f44 Delete dead variable.
llvm-svn: 264464
2016-03-25 21:46:44 +00:00
Eric Christopher
4650272310 The time when -faltivec (or, on clang only, -maltivec) will magically
include altivec.h has come and gone.

Rationale: This causes modules, rewrite-includes, etc to be sad and
people should just include altivec.h in their source.

llvm-svn: 264235
2016-03-24 01:26:08 +00:00
JF Bastien
f828bba5bf NFC: clarify comment on lock-free macros
Used by both libstdc++ and libc++.

llvm-svn: 264226
2016-03-24 00:20:44 +00:00
Nico Weber
fbe3adf10e clang-cl: With -fmsc-version=1900, use MSVS2015 diag formatting.
Remove tests that have neither a triple nor an explicit -fmsc-version flag,
since in the absence of an -fmsc-version flag, the implicit value of the flag
is 17 (MSVC2013) with MSVC triples but 0 (not set) for other triples, and
the default triple is platform dependent.

This relands r263974 with a test fix.

llvm-svn: 264210
2016-03-23 22:57:55 +00:00
Nico Weber
f54146c178 clang-cl: Fix remaining bugs in interaction of /Yc and /FI /showIncludes.
Instead of putting the /Yc header into ExtraDeps, give DependencyOutputOptions
a dedicated field for /Yc mode, and let HeaderIncludesCallback hang on to the
full DependencyOutputOptions object, not just ExtraDeps.

Reverts parts of r263352 that are now no longer needed.

llvm-svn: 264182
2016-03-23 18:46:57 +00:00
Nico Weber
149d9522fb clang-cl: Include /FI headers in /showIncludes output.
-H in gcc mode doesn't print -include headers, but they are included in
depfiles written by MMD and friends. Since /showIncludes is what's used instead
of depfiles, printing /FI there seems important (and matches cl.exe).

Instead of giving HeaderIncludeGen more options, just switch on ShowAllHeaders
in clang-cl mode and let clang::InitializePreprocessor() not put -include flags
in the <command line> block. This changes the behavior of -E slightly, and it
removes the <command line> flag from the output triggered by setting the
obscure CC_PRINT_HEADERS=1 env var to true while running clang. Both of these
seem ok to change.

http://reviews.llvm.org/D18401

llvm-svn: 264174
2016-03-23 18:00:22 +00:00
NAKAMURA Takumi
8794f98e21 Revert r263974, "clang-cl: With -fmsc-version=1900, use MSVS2015 diag formatting."
It seems the test wouldn't expect if default target is *-win32.

llvm-svn: 264007
2016-03-21 23:51:50 +00:00
Pete Cooper
948677131f Revert "Convert some ObjC msgSends to runtime calls."
This reverts commit r263607.

This change caused more objc_retain/objc_release calls in the IR but those
are then incorrectly optimized by the ARC optimizer.  Work is going to have
to be done to ensure the ARC optimizer doesn't optimize user written RR, but
that should land before this change.

This change will also need to be updated to take account for any changes required
to ensure that user written calls to RR are distinct from those inserted by ARC.

llvm-svn: 263984
2016-03-21 20:50:03 +00:00
Nico Weber
920341c7a9 clang-cl: With -fmsc-version=1900, use MSVS2015 diag formatting.
llvm-svn: 263974
2016-03-21 19:44:18 +00:00
Bruno Cardoso Lopes
d878e28e67 Reapply [2] [VFS] Add 'overlay-relative' field to YAML files
This reapplies r261552 and r263748. Fixed testcase to reapply.

The VFS overlay mapping between virtual paths and real paths is done through
the 'external-contents' entries in YAML files, which contains hardcoded paths
to the real files.

When a module compilation crashes, headers are dumped into <name>.cache/vfs
directory and are mapped via the <name>.cache/vfs/vfs.yaml. The script
generated for reproduction uses -ivfsoverlay pointing to file to gather the
mapping between virtual paths and files inside <name>.cache/vfs. Currently, we
are only capable of reproducing such crashes in the same machine as they
happen, because of the hardcoded paths in 'external-contents'.

To be able to reproduce a crash in another machine, this patch introduces a new
option in the VFS yaml file called 'overlay-relative'. When it's equal to
'true' it means that the provided path to the YAML file through the
-ivfsoverlay option should also be used to prefix the final path for every
'external-contents'.

Example, given the invocation snippet "... -ivfsoverlay
<name>.cache/vfs/vfs.yaml" and the following entry in the yaml file:

"overlay-relative": "true",
"roots": [
...
  "type": "directory",
  "name": "/usr/include",
  "contents": [
    {
      "type": "file",
      "name": "stdio.h",
      "external-contents": "/usr/include/stdio.h"
    },
...

Here, a file manager request for virtual "/usr/include/stdio.h", that will map
into real path "/<absolute_path_to>/<name>.cache/vfs/usr/include/stdio.h.

This is a useful feature for debugging module crashes in machines other than
the one where the error happened.

Differential Revision: http://reviews.llvm.org/D17457

rdar://problem/24499339

llvm-svn: 263893
2016-03-20 02:08:48 +00:00
Pirama Arumuga Nainar
8e2e9d6f4c Add -fnative-half-arguments-and-returns
Summary:
r246764 handled __fp16 arguments and returns for AAPCS, but skipped this
handling for OpenCL.  Simlar to OpenCL, RenderScript also handles __fp16
type natively.

This patch adds the -fnative-half-arguments-and-returns command line
flag to allow such languages to skip this coercion of __fp16.

Reviewers: srhines, olista01

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18138

llvm-svn: 263795
2016-03-18 16:58:36 +00:00
Bruno Cardoso Lopes
9e2f9d818f Revert "Reapply [VFS] Add 'overlay-relative' field to YAML files"
Tests failing on
http://bb.pgr.jp/builders/cmake-clang-x86_64-linux/builds/46102

This reverts commit a1683cd6c9e07359c09f86e98a4db6b4e1bc51fc.

llvm-svn: 263750
2016-03-17 21:30:55 +00:00
Bruno Cardoso Lopes
016b2d0ddc Reapply [VFS] Add 'overlay-relative' field to YAML files
This reapplies r261552.

The VFS overlay mapping between virtual paths and real paths is done through
the 'external-contents' entries in YAML files, which contains hardcoded paths
to the real files.

When a module compilation crashes, headers are dumped into <name>.cache/vfs
directory and are mapped via the <name>.cache/vfs/vfs.yaml. The script
generated for reproduction uses -ivfsoverlay pointing to file to gather the
mapping between virtual paths and files inside <name>.cache/vfs. Currently, we
are only capable of reproducing such crashes in the same machine as they
happen, because of the hardcoded paths in 'external-contents'.

To be able to reproduce a crash in another machine, this patch introduces a new
option in the VFS yaml file called 'overlay-relative'. When it's equal to
'true' it means that the provided path to the YAML file through the
-ivfsoverlay option should also be used to prefix the final path for every
'external-contents'.

Example, given the invocation snippet "... -ivfsoverlay
<name>.cache/vfs/vfs.yaml" and the following entry in the yaml file:

"overlay-relative": "true",
"roots": [
...
  "type": "directory",
  "name": "/usr/include",
  "contents": [
    {
      "type": "file",
      "name": "stdio.h",
      "external-contents": "/usr/include/stdio.h"
    },
...

Here, a file manager request for virtual "/usr/include/stdio.h", that will map
into real path "/<absolute_path_to>/<name>.cache/vfs/usr/include/stdio.h.

This is a useful feature for debugging module crashes in machines other than
the one where the error happened.

Differential Revision: http://reviews.llvm.org/D17457

rdar://problem/24499339

llvm-svn: 263748
2016-03-17 21:11:23 +00:00