Commit Graph

620 Commits

Author SHA1 Message Date
Eric Fiselier
00386077e1 Allow the CMake option 'LLVM_ABI_BREAKING_CHECKS' to be undefined.
When building libc++abi in a standalone configuration the CMake option
'LLVM_ABI_BREAKING_CHECKS` will not be defined.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237204 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 22:49:18 +00:00
Kostya Serebryany
8ae273d380 [lib/Fuzzer] use -fsanitize-coverage=trace-cmp when building LLVM with LLVM_USE_SANITIZE_COVERAGE; in lib/Fuzzer try to reload the corpus to pick up new units from other processes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236906 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-08 21:30:55 +00:00
Alexey Samsonov
8227e6a8b4 Update CMake flags, LibFuzzer comments and docs for new -fsanitize-coverage= flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236797 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 23:33:24 +00:00
Chris Bieneman
eb3bc0ba5f [CMake] Fix for PR 23328: LLVM_OPTIMIZED_TABLEGEN broken
In CMake dependencies can be filenames or targets, and targets can't be filenames. The Ninja generator handles filename dependencies because it generates targets for every output file from a command. For example:

add_custom_command(OUTPUT foo.txt COMMAND touch foo.txt)

With the Ninja generator this generates a target foo.txt, but with the Makefile generator it doesn't. This is probably because Ninja explicitly requires these hard dependency ties, and Make just behaves oddly in general.

To fix this we need to make the tablegen actions depend on a target rather than a filename.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235732 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-24 17:09:20 +00:00
Reid Kleckner
1606ccad09 [cmake] Quote the path to the target exports file, fixes PR23313
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235519 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 16:23:00 +00:00
Andrew Kaylor
550a1ca576 Silence MSVC build alignment warnings
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235450 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 22:29:38 +00:00
Pete Cooper
e6308656a6 Add targets to cmake for specific target components.
This adds the following targets to cmake.  These can be used to build and link only specific parts of a backend, instead of having to link the whole backend.

- AllTargetsAsmPrinters, AllTargetsAsmParsers, AllTargetsDescs, AllTargetsDisassemblers, AllTargetsInfos

A typical use for these is instead of linking ${LLVM_TARGETS_TO_BUILD}.  This commit changes llvm-mc to show how to use the new targets.

Reviewed by Chris Bieneman.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235324 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-20 18:22:05 +00:00
Chris Bieneman
e59dcc804f Cleanup based on rnk's feedback.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 18:08:33 +00:00
Chris Bieneman
3cdbd163d0 Fixing windows bots.
Third time's the try.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235123 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 17:40:51 +00:00
Chris Bieneman
578a18c4fc Better fix to the windows conditional.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235121 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 17:26:50 +00:00
Chris Bieneman
9e93b6429d Fix Windows bots.
Turns out Windows is special. All library installs are RUNTIME.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 17:25:17 +00:00
Chris Bieneman
1a0e0ea4fb Fixing a mis-use of the CMake install command.
The CMake install command is defined as:

install(TARGETS targets... [EXPORT <export-name>]
        [[ARCHIVE|LIBRARY|RUNTIME|FRAMEWORK|BUNDLE|
          PRIVATE_HEADER|PUBLIC_HEADER|RESOURCE]
         [DESTINATION <dir>]
         [INCLUDES DESTINATION [<dir> ...]]
         [PERMISSIONS permissions...]
         [CONFIGURATIONS [Debug|Release|...]]
         [COMPONENT <component>]
         [OPTIONAL] [NAMELINK_ONLY|NAMELINK_SKIP]
        ] [...])

This means it can only take one parameter from the set of RUNTIME, LIBRARY, or ARCHIVE. If you set more than one of these it seems to gobble up the extra arguments and ignore the COMPONENT argument.

This adds a check to only set LIBRARY or ARCHIVE based on whether or not the library being built is shared.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 16:56:18 +00:00
Zachary Turner
daa55a66a0 [msvc] Strip /W[0-4] before appending /W4
Certain versions of CMake specify /W3 as part of CMAKE_CXX_FLAGS
by default, before you do anything.  Appending /W4 to the end of
this and using the Ninja generator results in

cl : Command line warning D9025 : overriding '/W3' with '/W4'.

It is not possible to suppress this since it is a command line
warning and not a compiler warning, so we must fix the command
line to contain only one value for /Wn.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234907 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 16:57:54 +00:00
NAKAMURA Takumi
032f4a9ad1 [CMake] Uniquify LLVM_ABI_BREAKING_CHECKS. It reverts r233784, "[CMake] Cache in LLVMConfig.cmake."
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234720 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-13 04:54:12 +00:00
Rafael Espindola
6dc9f59df9 Disable all link optimizations in a debug build.
This taking linking clang on my machine with gold from 16.980257914 to
15.933037649 seconds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234161 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 15:04:31 +00:00
Rafael Espindola
e104aca94c Don't pass -O3 to the linker in debug builds.
This takes linking clang in a debug build with gold form 19.518925697 to
16.406388685 seconds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234160 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 14:51:01 +00:00
Rafael Espindola
29072c8fab Don't use -ffunction-sections -fdata-sections on debug builds.
Unfortunately, on ELF there is not used attribute on the .o files,
so there is no easy way to keep the dump function alive.

If we are not gcing, we may as well produce non gcable files and
avoid the cost.

Linking a debug clang now takes 18.856225992 seconds, before it
took 21.206897447.

I will try avoiding --gc-sections -O3 on a followup patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234159 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 14:34:43 +00:00
NAKAMURA Takumi
598eeb5703 Try to unbreak Clang build to export LLVM_ABI_BREAKING_CHECKS, fixup for r233310.
FIXME: Should ENABLE_ABI_BREAKING_CHECKS be tri-state, "ON/OFF/blank"?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233801 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-01 11:46:15 +00:00
Sanjoy Das
000e1b22e4 [CMake] Cache LLVM_ABI_BREAKING_CHECKS in LLVMConfig.cmake.
Not having this breaks clang builds that use an already-built LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233784 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-01 03:16:10 +00:00
Chris Bieneman
527745e789 [CMake] Removing duplicates from the list of test suites to generate targets for.
Not doing this causes some headaches for users migrating from autoconf to CMake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233428 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 21:45:49 +00:00
Derek Schuff
c18ea8d96e CMake: enable installing utils
Added a new boolean CMake flag, LLVM_INSTALL_UTILS. When set,
the 'install' target will include in the bin directory the
utils binaries - e.g. FileCheck. This mirrors the autoconfig
behavior.

Test Plan:
Locally verified that utils binaries are copied when flag is set,
and not copied when flag is not set.

Reviewers: jfb, dschuff, beanz

Reviewed By: beanz

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8587

Patch by Mircea Trofin

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233385 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 16:53:06 +00:00
Sanjoy Das
784545fba0 [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap
Summary:
This patch is an attempt at making `DenseMapIterator`s "fail-fast".
Fail-fast iterators that have been invalidated due to insertion into
the host `DenseMap` deterministically trip an assert (in debug mode)
on access, instead of non-deterministically hitting memory corruption
issues.

Enabling fail-fast iterators breaks the LLVM C++ ABI, so they are
predicated on `LLVM_ENABLE_ABI_BREAKING_CHECKS`.
`LLVM_ENABLE_ABI_BREAKING_CHECKS` by default flips with
`LLVM_ENABLE_ASSERTS`, but can be clamped to ON or OFF using the CMake /
autoconf build system.

Reviewers: chandlerc, dexonsmith, rnk, zturner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8351

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233310 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 19:25:01 +00:00
Andrew Kaylor
1e4e27a7a6 Disabling warnings for MSVC build to enable /W4 use.
Differential Revision: http://reviews.llvm.org/D8572



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233133 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 23:37:10 +00:00
Chris Bieneman
07118a3546 Re-land: Generate targets for each lit suite.
Summary:
This change makes CMake scan for lit suites and generate a target for each lit test suite. The targets follow the format check-<project>-<suite path>.

For example:
check-llvm-unit - Runs the LLVM unit tests
check-llvm-codegen-arm - Runs the ARM codeine tests

Note: These targets are not generated during multi-configuration generators (i.e. Xcode and Visual Studio) because target clutter impacts UI usability.

* Also fixed a minor issue that Duncan pointed out to me I was passing the suite to lit twice

Reviewers: chandlerc

Subscribers: aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D8380

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233009 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-23 20:04:00 +00:00
Chris Bieneman
0c9684c947 Raising minimum required CMake version to 2.8.12.2.
This commit is in reference to the llvm-dev thread: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-March/083672.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233008 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-23 20:03:57 +00:00
Chris Bieneman
a7c5163281 Fixing dependencies for native tablegen.
The dependencies for cross-built tablegen were a bit confused. This fixes that. The following dependencies are now enforced:

(1) Tablegen tasks depend on the native tablegen
(2) Native tablegen depends on the cross-compiled tablegen

Although the native tablegen doesn't actually require the cross tablegen, having this dependency forces the native tablegen to rebuild whenever the cross tablegen changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232730 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 16:49:44 +00:00
Greg Bedwell
c6e489793c [CMake] Don't pass in MSVC warning flags as definitions.
NFC currently but required as a prerequisite for using
the Microsoft resource compiler in conjunction with
CMake's ninja generator, which knows how to filter flags
appropriately, but not definitions.

Differential Revision: http://reviews.llvm.org/D8188

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232727 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 16:32:47 +00:00
Chris Bieneman
60858a7410 Revert "Generate targets for each lit suite."
This change broke Polly. I'll track down the failure when I have a chance and re-apply the change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232676 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-18 21:53:29 +00:00
Chris Bieneman
3bf045a9c6 Generate targets for each lit suite.
Summary:
This change makes CMake scan for lit suites and generate a target for each lit test suite. The targets follow the format check-<project>-<suite path>.

For example:
check-llvm-unit - Runs the LLVM unit tests
check-llvm-codegen-arm - Runs the ARM codeine tests

Note: These targets are not generated during multi-configuration generators (i.e. Xcode and Visual Studio) because target clutter impacts UI usability.

Reviewers: chandlerc

Subscribers: aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D8380

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232671 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-18 21:19:06 +00:00
Reid Kleckner
85ab1e7fe7 CMake: Disable ENABLE_EXPORTS for executables with MSVC
The MSVC linker won't produce a .lib file for an executable that doesn't
export anything, and LLVM doesn't maintain dllexport annotations or .def
files listing all C++ symbols. It also doesn't support exporting all
symbols, like binutils ld.

CMake 3.2 changed the Ninja generator to list both the .exe and .lib
files as outputs of executable build targets. Ninja would always re-link
executables with ENABLE_EXPORTS because the .lib output file was not
present, and therefore the target was out of date.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232662 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-18 20:09:13 +00:00
Chris Bieneman
a08ee010be Refactoring CMake CrossCompile module.
* put most of the cross-compiling support into a function llvm_create_cross_target_internal.
* when CrossCompile is included it still generates a NATIVE target.
* llvm_create_cross_target function takes a target_name which should match a toolchain.
* llvm_create_cross_target can now be used to target more than one cross-compilation target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232067 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-12 17:33:34 +00:00
Greg Bedwell
756a12d0d1 Revert "[CMake] Don't pass in MSVC warning flags as definitions"
reverting while I investigate why it broke the sanitizer-windows build.
This reverts commit r231924.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231925 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 14:57:48 +00:00
Greg Bedwell
264d962191 [CMake] Don't pass in MSVC warning flags as definitions
NFC currently but required as a prerequisite for using
the Microsoft resource compiler in conjunction with
CMake's ninja generator, which knows how to filter flags
appropriately, but not definitions.

Differential Revision: http://reviews.llvm.org/D8188

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231924 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 14:26:29 +00:00
Chris Bieneman
b8bf97b7e1 Add new LLVM_OPTIMIZED_TABLEGEN build setting which configures, builds and uses a release tablegen build when LLVM is configured with assertions enabled.
Summary: This change leverages the cross-compiling functionality in the build system to build a release tablegen executable for use during the build.

Reviewers: resistor, rnk

Reviewed By: rnk

Subscribers: rnk, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D7349

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231842 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 20:48:02 +00:00
Chandler Carruth
24a6fb0a17 Teach the LLVM CMake build how to explicitly use libc++abi when using
libc++. This lets me almost self-host on Linux with libc++ and libc++abi
very simply.

Currently, MCJIT and OrcJIT are failing due to uncaught exceptions, and
the Go binding tests are failing to build due to not linking in the
correct C++ standard library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231560 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-07 10:30:34 +00:00
Kostya Serebryany
ae0620c4e9 [sanitizer/coverage] Add AFL-style coverage counters (search heuristic for fuzzing).
Introduce -mllvm -sanitizer-coverage-8bit-counters=1
which adds imprecise thread-unfriendly 8-bit coverage counters.

The run-time library maps these 8-bit counters to 8-bit bitsets in the same way
AFL (http://lcamtuf.coredump.cx/afl/technical_details.txt) does:
counter values are divided into 8 ranges and based on the counter
value one of the bits in the bitset is set.
The AFL ranges are used here: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+.

These counters provide a search heuristic for single-threaded
coverage-guided fuzzers, we do not expect them to be useful for other purposes.

Depending on the value of -fsanitize-coverage=[123] flag,
these counters will be added to the function entry blocks (=1),
every basic block (=2), or every edge (=3).

Use these counters as an optional search heuristic in the Fuzzer library.
Add a test where this heuristic is critical.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231166 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 23:27:02 +00:00
Reid Kleckner
fd78a7dd5c cmake: Use MSVC atomics with clang-cl
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 22:00:23 +00:00
Chris Bieneman
b07ab5d546 Making the SO version major.minor instead of just major because ABI and API change between minor versions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230981 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-02 17:50:13 +00:00
Reid Kleckner
13c5474d35 Minor follow-ups to r229720 suggested on llvmdev
"svn" patch by Sedat Dilek plus trimming whitespace added in r229720.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230773 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 18:22:46 +00:00
Zachary Turner
814efef67f [CMake] Fix the clang-cl self host build.
This allows clang-cl to self-host cleanly with no magic setup
steps required.

After this patch, all you have to do is set CC=CXX=clang-cl and
run cmake -G Ninja.

These changes only exist to support C++ features which are
unsupported in clang-cl, so regardless of whether the user
specifies they want to use them, we still have to disable them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230539 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 20:42:19 +00:00
Saleem Abdulrasool
fb5edaa05c build: check if atomic routines are implicitly provided
It is possible for the atomic routines to be provided by the compiler without
requiring any additional libraries.  Check if that is the case before checking
for a library.

Patch by Matt Glazar!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230452 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 02:38:03 +00:00
Tobias Grosser
bc8f84c030 Revert "Raising minimum required CMake version to 2.8.12.2."
This reverts commit r230062.

Debian stable (wheezy) ships still with cmake 2.8.9.

The commit broke my LLVM/Polly buildbot, to my knowledge our only Linux+cmake
buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230343 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-24 16:39:46 +00:00
Chad Rosier
9659f43f10 Revert "Revert "Raising minimum required CMake version to 2.8.12.2.""
This reverts commit r230240, which was an accidental commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230246 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 19:34:04 +00:00
Chad Rosier
3986322604 Revert "Raising minimum required CMake version to 2.8.12.2."
This reverts commit 247aed4710.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230240 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 19:15:08 +00:00
Reid Kleckner
c38816e9d8 cmake: Don't do the libstdc++ version check when clang simulates MSVC
If we're using clang-cl, that's a pretty good indication that we're
going to use MSVC's STL.

This simplifies the clang-cl ninja self-host configuration down to:
CC=clang-cl CXX=clang-cl cmake .. -GNinja

Modified version of zturner's patch:
Differential Revision: http://reviews.llvm.org/D7824

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230239 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 19:07:25 +00:00
Chris Bieneman
247aed4710 Raising minimum required CMake version to 2.8.12.2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230062 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 21:28:18 +00:00
Peter Collingbourne
4c85f68fe4 CMake: Fix add_lit_target for the case where a test suite has zero target dependencies.
This can happen with a standalone project containing a test suite with no
internal dependencies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229753 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 22:25:35 +00:00
Chris Bieneman
bc20f6088d Adding install targets for individual LLVM tools and libraries.
Summary:
* add_llvm_tool and add_llvm_library now add install-${name} targets to install specific components
* added installhdrs target to install just the LLVM headers
* The above changes only apply for single-configuration generators (Ninja, Makefiles...), not for multi-configuration generators (Visual Studio, Xcode...)

Reviewers: pete

Reviewed By: pete

Subscribers: pete, llvm-commits

Differential Revision: http://reviews.llvm.org/D7619

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229727 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 19:25:47 +00:00
Chris Bieneman
56168c6553 Enable standard so versioning for libLLVM.
Summary: This resolves Bugzilla bug 15493.

Reviewers: chapuni, pete

Reviewed By: pete

Subscribers: pete, llvm-commits

Differential Revision: http://reviews.llvm.org/D6157

Conflicts:
	cmake/modules/AddLLVM.cmake

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229720 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 18:52:06 +00:00
Filipe Cabecinhas
c500f13606 Downgrade build system error message to a warning
Instead of requiring MSVC 2013 U4, we simply warn users, since some might
not bt able to immediately upgrade.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229598 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 01:12:38 +00:00