Commit Graph

166 Commits

Author SHA1 Message Date
Aaron Ballman
1d03d382c1 Reverting r315590; it did not include changes for llvm-tblgen, which is causing link errors for several people.
Error LNK2019 unresolved external symbol "public: void __cdecl `anonymous namespace'::MatchableInfo::dump(void)const " (?dump@MatchableInfo@?A0xf4f1c304@@QEBAXXZ) referenced in function "public: void __cdecl `anonymous namespace'::AsmMatcherEmitter::run(class llvm::raw_ostream &)" (?run@AsmMatcherEmitter@?A0xf4f1c304@@QEAAXAEAVraw_ostream@llvm@@@Z) llvm-tblgen D:\llvm\2017\utils\TableGen\AsmMatcherEmitter.obj 1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315854 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-15 14:32:27 +00:00
Don Hinton
5298935fe7 [dump] Remove NDEBUG from test to enable dump methods [NFC]
Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.

Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.

Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.

Differential Revision: https://reviews.llvm.org/D38406

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315590 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-12 16:16:06 +00:00
Reid Kleckner
5cc2236f0f [Support] - Add bad alloc error handler for handling allocation malfunctions
Summary:
Patch by Klaus Kretzschmar

We would like to introduce a new type of llvm error handler for handling
bad alloc fault situations.  LLVM already provides a fatal error handler
for serious non-recoverable error situations which by default writes
some error information to stderr and calls exit(1) at the end (functions
are marked as 'noreturn').

For long running processes (e.g. a server application), exiting the
process is not an acceptable option, especially not when the system is
in a temporary resource bottleneck with a good chance to recover from
this fault situation. In such a situation you would rather throw an
exception to stop the current compilation and try to overcome the
resource bottleneck. The user should be aware of the problem of throwing
an exception in bad alloc situations, e.g. you must not do any
allocations in the unwind chain. This is especially true when adding
exceptions in existing unfamiliar code (as already stated in the comment
of the current fatal error handler)

So the new handler can also be used to distinguish from general fatal
error situations where recovering is no option.  It should be used in
cases where a clean unwind after the allocation is guaranteed.

This patch contains:
- A report_bad_alloc function which calls a user defined bad alloc
  error handler. If no user handler is registered the
  report_fatal_error function is called. This function is not marked as
  'noreturn'.
- A install/restore_bad_alloc_error_handler to install/restore the bad
  alloc handler.
- An example (in Mutex.cpp) where the report_bad_alloc function is
  called in case of a malloc returns a nullptr.

If this patch gets accepted we would create similar patches to fix
corresponding malloc/calloc usages in the llvm code.

Reviewers: chandlerc, greened, baldrick, rnk

Reviewed By: rnk

Subscribers: llvm-commits, MatzeB

Differential Revision: https://reviews.llvm.org/D34753

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307673 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-11 16:45:30 +00:00
George Rimar
b62f430846 [Support/Compiler.h] - Use gnu::fallthrough for LLVM_FALLTHROUGH when available.
I tried to compile LLD using GCC 7.1.0 and got warnings like 
"warning: this statement may fall through [-Wimplicit-fallthrough=]"
(some more details are here: D32907)

GCC's __cplusplus value is 201402L by default, so macro expands to nothing,
though GCC 7 has support for [[fallthrough]].

Patch uses gnu::fallthrough when it is available and fixes warning I am observing.

Initial idea of way to fix belongs to Davide Italiano.

Differential revision: https://reviews.llvm.org/D33036

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302878 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-12 06:53:48 +00:00
Serge Guelton
d35f86ef8f Suppress all uses of LLVM_END_WITH_NULL. NFC.
Use variadic templates instead of relying on <cstdarg> + sentinel.
This enforces better type checking and makes code more readable.

Differential Revision: https://reviews.llvm.org/D32541


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302571 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-09 19:31:13 +00:00
NAKAMURA Takumi
23a948a82f Trailing whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299344 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-02 23:57:17 +00:00
Matthias Braun
88d207542b Cleanup dump() functions.
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html

For reference:
- Public headers should just declare the dump() method but not use
  LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MyClass::dump() {
    // print stuff to dbgs()...
  }
  #endif

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293359 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-28 02:02:38 +00:00
Justin Lebar
6feedc56f7 Remove LLVM_CONSTEXPR.
Summary: With MSVC 2013 and GCC < 4.8 gone, we can use the "constexpr" keyword.

Reviewers: bkramer, mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25901

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284947 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-23 19:39:16 +00:00
Benjamin Kramer
cafdc34428 [Support] Remove llvm::alignOf now that all uses are gone.
Also clean up the legacy hacks for AlignedCharArray. I'm keeping
LLVM_ALIGNAS alive for a bit longer because GCC 4.8.0 (which we still
support apparently) shipped a buggy alignas(). All other supported
compilers have a working alignas.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284736 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 15:36:38 +00:00
Reid Kleckner
3a3c5c8815 Use __func__ directly now that all supported compilers support it
Remove the portability macro now that it is unused.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284681 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 00:22:23 +00:00
Reid Kleckner
5b1c9f3223 Remove LLVM_NOEXCEPT and replace it with noexcept
Now that we have dropped MSVC 2013, all supported compilers support
noexcept and we can drop this portability macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284672 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-19 23:52:38 +00:00
Reid Kleckner
6224e335f0 Update Compiler.h to fail fast when building with MSVC 2013
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284665 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-19 23:34:58 +00:00
Rafael Espindola
8ddbe891dd Add a macro for prefetching data.
It will be used in lld.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284626 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-19 18:34:32 +00:00
Justin Bogner
0ebe9c2f81 Support: Drop LLVM_ATTRIBUTE_UNUSED_RESULT
Uses of this have all been updated to use LLVM_NODISCARD, which
matches the C++17 [[nodiscard]] semantics rather than those of GCC's
__attribute__((warn_unused_result)).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284367 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-17 07:37:11 +00:00
Justin Bogner
6a2dc096c9 Support: Add LLVM_NODISCARD with C++17's [[nodiscard]] semantics
This is essentially a more powerful version of our current
LLVM_ATTRIBUTE_UNUSED_RESULT, in that it can also be applied to types
and generate warnings whenever an object of that type is returned by
value and the value is discarded.

I'll replace uses of LLVM_ATTRIBUTE_UNUSED_RESULT and remove that
macro in follow up commits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284286 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-14 22:04:17 +00:00
Justin Bogner
ba2b23190e Support: Avoid errors with LLVM_FALLTHROUGH in clang 3.6 and below in C mode
Older versions of clang defined __has_cpp_attribute in C mode, but
would choke on scoped attributes, as per llvm.org/PR23435. Since we
support building with clang all the way back to 3.1, we have to work
around this issue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280326 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-31 23:43:14 +00:00
Chandler Carruth
731ba1dedb Restrict the use of the C++17 attribute to C++17 (at least as best we
can given the current __cplusplus definitions).

Without this, Clang triggers TONS of warnings about using a C++17
extension. I tried using LLVM_EXTENSION to turn these off and it doesn't
work.

Suggestions on a better approach are welcome, but at least this makes
the build usable for me again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278909 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-17 07:18:44 +00:00
Justin Bogner
e24b74a90a Introduce LLVM_FALLTHROUGH, which expands to the C++17 attribute.
This allows you to annotate switch case fallthrough in a better way
than a "// FALLTHROUGH" comment. Eventually it would be nice to turn
on -Wimplicit-fallthrough, if we can get the code base clean.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278868 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-16 23:24:13 +00:00
Zachary Turner
dc89d2a880 Make LLVM_PRETTY_FUNCTION support __func__.
In case there are compilers that support neither __FUNCSIG__ or
__PRETTY_FUNCTION__, we fall back to __func__ as a last resort,
which should be guaranteed by C++11 and C99.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278176 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-09 23:03:55 +00:00
Zachary Turner
a533deff7a Add a platform independent version of __PRETTY_FUNCTION__.
MSVC doesn't have this, it only has __FUNCSIG__.  So this adds
a new macro called LLVM_PRETTY_FUNCTION which evaluates to the
right thing on any platform.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278170 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-09 22:03:45 +00:00
Kuba Brecka
5a9fa77faf Add #ifdef __cplusplus around extern "C" in Compiler.h. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278119 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-09 12:12:15 +00:00
Mark Lacey
2a9c5591ed Add an LLVM_BUILTIN_DEBUGTRAP macro.
Summary:
This provides a macro that expands to __builtin_debugtrap() for clang,
and __debugbreak() for MSVC.

It intentionally expands to nothing for compilers that do not support a
similar mechanism that halts the debugger without otherwise crashing the
process.

Differential Revision: http://reviews.llvm.org/D18002

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263095 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-10 05:15:03 +00:00
Justin Bogner
aac07fb758 Annotate our undefined behaviour to sneak it past the sanitizers
We have known UB in some ilists where we static cast half nodes to
(larger) derived types and use the address. See llvm.org/PR26753.

This needs to be fixed, but in the meantime it'd be nice if running
ubsan didn't complain. This adds annotations in the two places where
ubsan complains while running check-all of a sanitized clang build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262683 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-04 01:52:47 +00:00
Reid Kleckner
88dea5d1ef Enable constexpr on Visual Studio 2015, add support for two equivalent attributes
Patch by Alexander Riccio

This patch enables `constexpr` on Visual Studio 2015 by adding `||
LLVM_MSC_PREREQ(1900)` to the preprocessor `#if` statement. Since VS2013
doesn't support `constexpr`, that's purposely excluded. The
`LLVM_CONSTEXPR` macro is used in ~25 places.

I also added the MSVC/SAL equivalent of:

  - `__attribute__((__warn_unused_result__))` as an
    `LLVM_ATTRIBUTE_UNUSED_RESULT` definition

  - `__attribute__((returns_nonnull))` as an
    `LLVM_ATTRIBUTE_RETURNS_NONNULL` definition

...in case anybody ever decides to run `/analyze` on LLVM (probably
myself, if anybody)

Reviewers: rnk, aaron.ballman

Differential Revision: http://reviews.llvm.org/D16751

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260410 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 19:07:47 +00:00
Justin Bogner
d5841c9f1f Support: Teach Asan about BumpPtrAllocator
Based on patch by Pete Cooper.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254964 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-07 23:12:26 +00:00
Xinliang David Li
83b18356e6 Define portable macros for packed struct definitions:
1. A macro with argument: LLVM_PACKED(StructDefinition)
 2. A pair of macros defining scope of region with packing:
    LLVM_PACKED_START
     struct A { ... };
     struct B { ... };
    LLVM_PACKED_END

Differential Revision: http://reviews.llvm.org/D14337


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252099 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 23:42:56 +00:00
Chandler Carruth
cfffa6e06a [Support] Fix the always_inline attribute macro to not include the
'inline' specifier. That specifier may or may not be valid for a given
function, or it may be required for correct linkage even when the
compiler doesn't support the always_inline attribute.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247252 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-10 08:29:30 +00:00
Naomi Musgrave
950c00954a Rollback of commit "Repress sanitization on User dtor."
This would have suppressed bug 24578, about use-after-
destroy on User and MDNode. Rolled back suppression for
the sake of code cleanliness, in preferance for bug
tracking to keep track of this issue.

This reverts commit 6ff2baabc4625d5b0a8dccf76aa0f72d930ea6c0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 21:06:08 +00:00
Naomi Musgrave
9f952dd0f6 Undo reversion on commit: Revert "Revert "Repress sanitization on User dtor.
Modify msan macros for applying attribute""

This reverts commit 020e70a798.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246470 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 18:49:31 +00:00
Naomi Musgrave
020e70a798 Revert "Repress sanitization on User dtor. Modify msan macros for applying attribute"
This reverts commit 5e3bfbb38eb3fb6f568b107f6b239e0aa4c5f334.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246450 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 16:26:44 +00:00
Naomi Musgrave
e2bfe6d6a1 Repress sanitization on User dtor. Modify msan macros for applying attribute
to repress sanitization. Move attribute for repressing sanitization to
operator delete for User, MDNode.

Summary: In response to bug 24578, reported against failing LLVM test.

Reviewers: chandlerc, rsmith, eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12335

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246449 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 15:57:40 +00:00
Peter Collingbourne
bf5dca5930 Support: Clean up TSan annotations.
Remove support for Valgrind-based TSan, which hasn't been maintained for a
few years. We now use the TSan annotations only if LLVM is compiled with
-fsanitize=thread. We no longer need the weak function definitions as we
are guaranteed that our program is linked directly with the TSan runtime.

Differential Revision: http://reviews.llvm.org/D12121

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245374 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-18 22:31:24 +00:00
David Blaikie
deae476f2c -Wdeprecated-clean: Remove uses of throw() in favor of noexcept
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244115 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-05 20:38:57 +00:00
Benjamin Kramer
0ed5091742 Remove macro guards for extern template instantiations.
This is a C++11 feature that both GCC and MSVC have supported as ane extension
long before C++11 was approved.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242042 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-13 17:21:31 +00:00
Rafael Espindola
9751e35f20 Simplify now that we always use an alignment of 2 for ELF files.
This saves 123144 bytes out of llvm-nm on powerpc64le.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238824 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-02 12:05:27 +00:00
Peter Collingbourne
7e452b8b73 Revert r237766, "Support: Introduce LLVM_FALLTHROUGH macro."
The value of this macro seems to be very low unless we actually start
using it everywhere, and I don't have immediate plans to make that
happen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237941 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 19:44:44 +00:00
Peter Collingbourne
ed5afe4277 Support: Introduce LLVM_FALLTHROUGH macro.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237766 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-20 02:44:14 +00:00
Richard Smith
6f6cc8c81f Fix some minor abuse of C++ terminology in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-07 00:14:27 +00:00
Benjamin Kramer
7368f2145a Mark BumpPtrAllocator::Allocate as returning a noalias pointer.
The GCC attribute is curiously named 'malloc', but I think it's better
to use LLVM terminology for the wrapper macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234121 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-05 17:02:25 +00:00
Reid Kleckner
2647380f59 Add an LLVM_PTR_SIZE macro to make LLVM_ALIGNAS more useful
MSVC 2013 requires the argument to __declspec(align()) to be an integer
constant expression that doesn't involve any identifiers like sizeof.

For GCC and Clang, LLVM_PTR_SIZE is equivalent to __SIZEOF_POINTER__,
which dates back to GCC 4.6 and Clang 2010. If that's not available, we
get sizeof(void*), which works with alignas() and
__attribute__((aligned())).

For MSVC, LLVM_PTR_SIZE is 4 or 8 depending on _WIN64.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233929 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-02 17:43:35 +00:00
Benjamin Kramer
efdcf3d62d [support] Add a macro wrapper for alignas and simplify some code.
We wrap __attribute((aligned)) for GCC 4.7 and __declspec(align) for
MSVC. The latter behaves weird in some contexts so this should be used
carefully.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233910 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-02 11:32:48 +00:00
Aaron Ballman
8b0b0a8524 I believe we no longer require LLVM_HAS_INITIALIZER_LISTS; it's supported in MSVC 2013 and GCC. Added a trivial test to ensure the ArrayRef initializer list constructor is called and behaves as expected.
If any of the bots complain (perhaps due to an antiquated version of an STL implementation), I will revert.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229502 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 15:37:53 +00:00
Aaron Ballman
66981fe208 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:54:22 +00:00
Aaron Ballman
d898d31ebc Removing LLVM_EXPLICIT, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229335 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:00:20 +00:00
Aaron Ballman
734d358274 Since MSVC 1800 is our lowest common denominator, we don't need an explicit check for it in these macros any longer; NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229333 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 21:21:52 +00:00
Benjamin Kramer
5d6f0738e3 Remove LLVM_HAS_VARIADIC_TEMPLATES and all the faux variadic workarounds guarded by it.
We no longer support compilers without variadic template support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229324 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 19:34:28 +00:00
Benjamin Kramer
cd2a5f28b1 Update the docs to require at least MSVC 2013.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229323 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 19:34:17 +00:00
Aaron Ballman
a4109ad7b9 Now use the __debugbreak intrinsic instead of calling RaiseException; it requires no forward declares and still calls VEH.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228745 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 21:13:04 +00:00
Aaron Ballman
7bddff5443 Changing the status code generated by LLVM_BUILTIN_TRAP on Windows to be something categorized as a valid error code. Fixes crashing uses (such as not --crash) with existing sys::Wait behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228738 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 20:13:52 +00:00
Aaron Ballman
8be1058946 Re-committing r228628 with a fix for 64-bit builds.
On Windows, we now use RaiseException to generate the kind of trap we require (one which calls our vectored exception handler), and fall back to using a volatile write to simulate a trap elsewhere.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228691 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 14:28:11 +00:00