Commit Graph

1292 Commits

Author SHA1 Message Date
Heejin Ahn c647919933 [WebAssembly] Use Windows EH instructions for Wasm EH
Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes wasm EH uses Windows EH instructions, with some changes:
1. Because wasm uses a single catch block to catch all C++ exceptions,
   this merges all catch clauses into a single catchpad, within which we
   test the EH selector as in Itanium EH.
2. Generates a call to `__clang_call_terminate` in case a cleanup
   throws. Wasm does not have a runtime to handle this.
3. In case there is no catch-all clause, inserts a call to
   `__cxa_rethrow` at the end of a catchpad in order to unwind to an
   enclosing EH scope.

Reviewers: majnemer, dschuff

Subscribers: jfb, sbc100, jgravelle-google, sunfish, cfe-commits

Differential Revision: https://reviews.llvm.org/D44931

llvm-svn: 333703
2018-05-31 22:18:13 +00:00
Simon Tatham 89e31fa7fc Support __iso_volatile_load8 etc on aarch64-win32.
These intrinsics are used by MSVC's header files on AArch64 Windows as
well as AArch32, so we should support them for both targets. I've
factored them out of CodeGenFunction::EmitARMBuiltinExpr into separate
functions that EmitAArch64BuiltinExpr can call as well.

Reviewers: javed.absar, mstorsjo

Reviewed By: mstorsjo

Subscribers: kristof.beyls, cfe-commits

Differential Revision: https://reviews.llvm.org/D47476

llvm-svn: 333513
2018-05-30 07:54:05 +00:00
Yaxun Liu 00ddbed298 Revert r332982 Call CreateTempMemWithoutCast for ActiveFlag
Due to regression on arm.

llvm-svn: 332991
2018-05-22 16:13:07 +00:00
Yaxun Liu 8a60e5db70 Call CreateTempMemWithoutCast for ActiveFlag
Introduced CreateMemTempWithoutCast and CreateTemporaryAllocaWithoutCast to emit alloca
without casting to default addr space.

ActiveFlag is a temporary variable emitted for clean up. It is defined as AllocaInst* type and there is
a cast to AlllocaInst in SetActiveFlag. An alloca casted to generic pointer causes assertion in
SetActiveFlag.

Since there is only load/store of ActiveFlag, it is safe to use the original alloca, therefore use
CreateMemTempWithoutCast is called.

Differential Revision: https://reviews.llvm.org/D47099

llvm-svn: 332982
2018-05-22 14:36:26 +00:00
Yaxun Liu a2a9cfab83 CodeGen: Fix invalid bitcast for lifetime.start/end
lifetime.start/end expects pointer argument in alloca address space.
However in C++ a temporary variable is in default address space.

This patch changes API CreateMemTemp and CreateTempAlloca to
get the original alloca instruction and pass it lifetime.start/end.

It only affects targets with non-zero alloca address space.

Differential Revision: https://reviews.llvm.org/D45900

llvm-svn: 332593
2018-05-17 11:16:35 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Akira Hatanaka ccda3d2970 [CodeGen] Avoid destructing a callee-destructued struct type in a
function if a function delegates to another function.

Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.

This reapplies r331016, which was reverted in r331019 because it caused
an assertion to fail in EmitDelegateCallArg on a windows bot. I made
changes to EmitDelegateCallArg so that it doesn't try to deactivate
cleanups for structs that have trivial destructors (cleanups for those
structs are never pushed to the cleanup stack in EmitParmDecl).

rdar://problem/39194693

Differential Revision: https://reviews.llvm.org/D45382

llvm-svn: 331020
2018-04-27 06:57:00 +00:00
Akira Hatanaka b4f3637cec Revert "[CodeGen] Avoid destructing a callee-destructued struct type in a"
This reverts commit r331016, which broke a windows bot.

http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/11727

llvm-svn: 331019
2018-04-27 05:56:55 +00:00
Akira Hatanaka e712374496 [CodeGen] Avoid destructing a callee-destructued struct type in a
function if a function delegates to another function.

Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.

rdar://problem/39194693

Differential Revision: https://reviews.llvm.org/D45382

llvm-svn: 331016
2018-04-27 04:21:51 +00:00
Keith Wyss f437e35671 [XRay] Add clang builtin for xray typed events.
Summary:
A clang builtin for xray typed events. Differs from
__xray_customevent(...) by the presence of a type tag that is vended by
compiler-rt in typical usage. This allows xray handlers to expand logged
events with their type description and plugins to process traced events
based on type.

This change depends on D45633 for the intrinsic definition.

Reviewers: dberris, pelikan, rnk, eizan

Subscribers: cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D45716

llvm-svn: 330220
2018-04-17 21:32:43 +00:00
Akira Hatanaka 617e26152d Add a command line option 'fregister_global_dtors_with_atexit' to
register destructor functions annotated with __attribute__((destructor))
using __cxa_atexit or atexit.

Register destructor functions annotated with __attribute__((destructor))
calling __cxa_atexit in a synthesized constructor function instead of
emitting references to the functions in a special section.

The primary reason for adding this option is that we are planning to
deprecate the __mod_term_funcs section on Darwin in the future. This
feature is enabled by default only on Darwin. Users who do not want this
can use command line option 'fno_register_global_dtors_with_atexit' to
disable it.

rdar://problem/33887655

Differential Revision: https://reviews.llvm.org/D45578

llvm-svn: 330199
2018-04-17 18:41:52 +00:00
Alexey Bataev ddf3db9b5e [OPENMP] Code cleanup + formatting, NFC.
llvm-svn: 330040
2018-04-13 17:31:06 +00:00
Alexander Kornienko 2a8c18d991 Fix typos in clang
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
2018-04-06 15:14:32 +00:00
Richard Smith e78fac5126 PR36992: do not store beyond the dsize of a class object unless we know
the tail padding is not reused.

We track on the AggValueSlot (and through a couple of other
initialization actions) whether we're dealing with an object that might
share its tail padding with some other object, so that we can avoid
emitting stores into the tail padding if that's the case. We still
widen stores into tail padding when we can do so.

Differential Revision: https://reviews.llvm.org/D45306

llvm-svn: 329342
2018-04-05 20:52:58 +00:00
Reid Kleckner 399d96e39c [MS] Emit vftable thunks for functions with incomplete prototypes
Summary:
The following class hierarchy requires that we be able to emit a
this-adjusting thunk for B::foo in C's vftable:

  struct Incomplete;
  struct A {
    virtual A* foo(Incomplete p) = 0;
  };
  struct B : virtual A {
    void foo(Incomplete p) override;
  };
  struct C : B { int c; };

This TU is valid, but lacks a definition of 'Incomplete', which makes it
hard to build a thunk for the final overrider, B::foo.

Before this change, Clang gives up attempting to emit the thunk, because
it assumes that if the parameter types are incomplete, it must be
emitting the thunk for optimization purposes. This is untrue for the MS
ABI, where the implementation of B::foo has no idea what thunks C's
vftable may require. Clang needs to emit the thunk without necessarily
having access to the complete prototype of foo.

This change makes Clang emit a musttail variadic call when it needs such
a thunk. I call these "unprototyped" thunks, because they only prototype
the "this" parameter, which must always come first in the MS C++ ABI.

These thunks work, but they create ugly LLVM IR. If the call to the
thunk is devirtualized, it will be a call to a bitcast of a function
pointer. Today, LLVM cannot inline through such a call, but I want to
address that soon, because we also use this pattern for virtual member
pointer thunks.

This change also implements an old FIXME in the code about reusing the
thunk's computed CGFunctionInfo as much as possible. Now we don't end up
computing the thunk's mangled name and arranging it's prototype up to
around three times.

Fixes PR25641

Reviewers: rjmccall, rsmith, hans

Subscribers: Prazek, cfe-commits

Differential Revision: https://reviews.llvm.org/D45112

llvm-svn: 329009
2018-04-02 20:20:33 +00:00
Eric Fiselier fa752f23cc [Builtins] Overload __builtin_operator_new/delete to allow forwarding to usual allocation/deallocation functions.
Summary:
Libc++'s default allocator uses `__builtin_operator_new` and `__builtin_operator_delete` in order to allow the calls to new/delete to be ellided. However, libc++ now needs to support over-aligned types in the default allocator. In order to support this without disabling the existing optimization Clang needs to support calling the aligned new overloads from the builtins.

See llvm.org/PR22634 for more information about the libc++ bug.

This patch changes `__builtin_operator_new`/`__builtin_operator_delete` to call any usual `operator new`/`operator delete` function. It does this by performing overload resolution with the arguments passed to the builtin to determine which allocation function to call. If the selected function is not a usual allocation function a diagnostic is issued.

One open issue is if the `align_val_t` overloads should be considered "usual" when `LangOpts::AlignedAllocation` is disabled.


In order to allow libc++ to detect this new behavior the value for `__has_builtin(__builtin_operator_new)` has been updated to `201802`.

Reviewers: rsmith, majnemer, aaron.ballman, erik.pilkington, bogner, ahatanak

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43047

llvm-svn: 328134
2018-03-21 19:19:48 +00:00
Akira Hatanaka 797afe3a4e [CodeGen] Ignore OpaqueValueExprs that are unique references to their
source expressions when iterating over a PseudoObjectExpr's semantic
subexpression list.

Previously the loop in emitPseudoObjectExpr would emit the IR for each
OpaqueValueExpr that was in a PseudoObjectExpr's semantic-form
expression list and use the result when the OpaqueValueExpr later
appeared in other expressions. This caused an assertion failure when
AggExprEmitter tried to copy the result of an OpaqueValueExpr and the
copied type didn't have trivial copy/move constructors or assignment
operators.

This patch adds flag IsUnique to OpaqueValueExpr which indicates it is a
unique reference to its source expression (it is not used in multiple
places). The loop in emitPseudoObjectExpr ignores OpaqueValueExprs that
are unique and CodeGen visitors simply traverse the source expressions
of such OpaqueValueExprs.

rdar://problem/34363596

Differential Revision: https://reviews.llvm.org/D39562

llvm-svn: 327939
2018-03-20 01:47:58 +00:00
Akira Hatanaka d791e92b5f [ObjC] Allow declaring __weak pointer fields in C structs in ARC.
This patch uses the infrastructure added in r326307 for enabling
non-trivial fields to be declared in C structs to allow __weak fields in
C structs in ARC.

This recommits r327206, which was reverted because it caused
module-enabled builders to fail. I discovered that the
CXXRecordDecl::CanPassInRegisters flag wasn't being set correctly in
some cases after I moved it to RecordDecl.

Thanks to Eric Liu for helping me investigate the bug.

rdar://problem/33599681

https://reviews.llvm.org/D44095

llvm-svn: 327870
2018-03-19 17:38:40 +00:00
Yaxun Liu 5b330e8d61 Recommit r326946 after reducing CallArgList memory footprint
llvm-svn: 327634
2018-03-15 15:25:19 +00:00
Sjoerd Meijer 95da875898 This reverts "r327189 - [ARM] Add ARMv8.2-A FP16 vector intrinsic"
This is causing problems in testing, and PR36683 was raised.
Reverting it until we have sorted out how to pass f16 vectors.

llvm-svn: 327437
2018-03-13 19:38:56 +00:00
Akira Hatanaka be7daa3d50 Revert "[ObjC] Allow declaring __weak pointer fields in C structs in
ARC."

This reverts commit r327206 as there were test failures caused by this
patch.

http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180312/221427.html

llvm-svn: 327294
2018-03-12 17:05:06 +00:00
Akira Hatanaka c181b127c0 [ObjC] Allow declaring __weak pointer fields in C structs in ARC.
This patch uses the infrastructure added in r326307 for enabling
non-trivial fields to be declared in C structs to allow __weak fields in
C structs in ARC.

rdar://problem/33599681

Differential Revision: https://reviews.llvm.org/D44095

llvm-svn: 327206
2018-03-10 06:36:08 +00:00
Richard Smith 007cb6df58 Revert r326946. It caused stack overflows by significantly increasing the size of a CallArgList.
llvm-svn: 327195
2018-03-10 01:47:22 +00:00
Abderrazek Zaafrani 5bd68cf742 [ARM] Add ARMv8.2-A FP16 vector intrinsic
Add the fp16 neon vector intrinsic for ARM as described in the ARM ACLE document.

Reviews in https://reviews.llvm.org/D43650

llvm-svn: 327189
2018-03-09 23:39:34 +00:00
Yaxun Liu 06dd81149f CodeGen: Fix address space of indirect function argument
The indirect function argument is in alloca address space in LLVM IR. However,
during Clang codegen for C++, the address space of indirect function argument
should match its address space in the source code, i.e., default addr space, even
for indirect argument. This is because destructor of the indirect argument may
be called in the caller function, and address of the indirect argument may be
taken, in either case the indirect function argument is expected to be in default
addr space, not the alloca address space.

Therefore, the indirect function argument should be mapped to the temp var
casted to default address space. The caller will cast it to alloca addr space
when passing it to the callee. In the callee, the argument is also casted to the
default address space and used.

CallArg is refactored to facilitate this fix.

Differential Revision: https://reviews.llvm.org/D34367

llvm-svn: 326946
2018-03-07 21:45:40 +00:00
Alexey Bataev ab4ea225fe [OPENMP] Fix lifetime of the loop counters.
We may emit incorrect lifetime info during codegen for loop counters in
OpenMP constructs because of automatic scope cleanup when we needed
temporarily locations for private loop counters.

llvm-svn: 326922
2018-03-07 18:17:06 +00:00
Akira Hatanaka 7275da0f2e [ObjC] Allow declaring __strong pointer fields in structs in Objective-C
ARC mode.

Declaring __strong pointer fields in structs was not allowed in
Objective-C ARC until now because that would make the struct non-trivial
to default-initialize, copy/move, and destroy, which is not something C
was designed to do. This patch lifts that restriction.

Special functions for non-trivial C structs are synthesized that are
needed to default-initialize, copy/move, and destroy the structs and
manage the ownership of the objects the __strong pointer fields point
to. Non-trivial structs passed to functions are destructed in the callee
function.

rdar://problem/33599681

Differential Revision: https://reviews.llvm.org/D41228

llvm-svn: 326307
2018-02-28 07:15:55 +00:00
Yaxun Liu fa13d015a3 [OpenCL] Fix __enqueue_block for block with captures
The following test case causes issue with codegen of __enqueue_block

void (^block)(void) = ^{ callee(id, out); };

enqueue_kernel(queue, 0, ndrange, block);
Clang first does codegen for block expression in the first line and deletes its block info.
Clang then tries to do codegen for the same block expression again for the second line,
and fails because the block info is gone.

The fix is to do normal codegen for both lines. Introduce an API to OpenCL runtime to
record llvm block invoke function and llvm block literal emitted for each AST block
expression, and use the recorded information for generating the wrapper kernel.

The EmitBlockLiteral APIs are cleaned up to minimize changes to the normal codegen
of blocks.

Another minor issue is that some clean up AST expression is generated for block
with captures, which can be stripped by IgnoreImplicit.

Differential Revision: https://reviews.llvm.org/D43240

llvm-svn: 325264
2018-02-15 16:39:19 +00:00
Reid Kleckner b75a3f04ec [WinEH] Put funclet bundles on inline asm calls
Summary:
Fixes PR36247, which is where WinEHPrepare replaces inline asm in
funclets with unreachable.

Make getBundlesForFunclet return by value to simplify some call sites.

Reviewers: smeenai, majnemer

Subscribers: eraman, cfe-commits

Differential Revision: https://reviews.llvm.org/D43033

llvm-svn: 324689
2018-02-09 00:16:41 +00:00
Sander de Smalen 891af03a55 Recommit rL323952: [DebugInfo] Enable debug information for C99 VLA types.
Fixed build issue when building with g++-4.8 (specialization after instantiation).

llvm-svn: 324173
2018-02-03 13:55:59 +00:00
Eric Fiselier 88df555d05 Emit label names according to -discard-value-names.
Summary:
Previously, Clang only emitted label names in assert builds.
However there is a CC1 option -discard-value-names that should have been used to control emission instead.
    
This patch removes the NDEBUG preprocessor block and instead allows LLVM to handle removing the names in accordance with the option.


Reviewers: erichkeane, aaron.ballman, majnemer

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D42829

llvm-svn: 324127
2018-02-02 19:58:34 +00:00
Sander de Smalen 4e9a1264dd Reverting patch rL323952 due to build errors that I
haven't encountered in local builds.

llvm-svn: 323956
2018-02-01 12:27:13 +00:00
Sander de Smalen 17c4633e7f [DebugInfo] Enable debug information for C99 VLA types
Summary:
This patch enables debugging of C99 VLA types by generating more precise
LLVM Debug metadata, using the extended DISubrange 'count' field that
takes a DIVariable.
    
This should implement:
  Bug 30553: Debug info generated for arrays is not what GDB expects (not as good as GCC's)
https://bugs.llvm.org/show_bug.cgi?id=30553

Reviewers: echristo, aprantl, dexonsmith, clayborg, pcc, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: jholewinski, schweitz, davide, fhahn, JDevlieghere, cfe-commits

Differential Revision: https://reviews.llvm.org/D41698

llvm-svn: 323952
2018-02-01 11:25:10 +00:00
Ivan A. Kosarev 1860b520a2 [CodeGen] Decorate aggregate accesses with TBAA tags
Differential Revision: https://reviews.llvm.org/D41539

llvm-svn: 323421
2018-01-25 14:21:55 +00:00
Alexey Bataev 647dd84422 [OPENMP] Initial codegen for `target teams distribute parallel for
simd`.

Added host codegen + codegen for devices with default codegen for
`#pragma omp target teams distribute parallel for simd` directive.

llvm-svn: 322515
2018-01-15 20:59:40 +00:00
John McCall 5cdf038374 Allocate and access NormalCleanupDest with the natural alignment of i32.
This alignment can be less than 4 on certain embedded targets, which may
not even be able to deal with 4-byte alignment on the stack.

Patch by Jacob Young!

llvm-svn: 322406
2018-01-12 22:07:01 +00:00
Alexey Bataev 475a7440f1 [OPENMP] Replace calls of getAssociatedStmt().
getAssociatedStmt() returns the outermost captured statement for the
OpenMP directive. It may return incorrect region in case of combined
constructs. Reworked the code to reduce the number of calls of
getAssociatedStmt() and used getInnermostCapturedStmt() and
getCapturedStmt() functions instead.
In case of firstprivate variables it may lead to an extra allocas
generation for private copies even if the variable is passed by value
into outlined function and could be used directly as private copy.

llvm-svn: 322393
2018-01-12 19:39:11 +00:00
Erich Keane 281d20b601 Implement Attribute Target MultiVersioning
GCC's attribute 'target', in addition to being an optimization hint,
also allows function multiversioning. We currently have the former
implemented, this is the latter's implementation.

This works by enabling functions with the same name/signature to coexist,
so that they can all be emitted. Multiversion state is stored in the
FunctionDecl itself, and SemaDecl manages the definitions.
Note that it ends up having to permit redefinition of functions so
that they can all be emitted. Additionally, all versions of the function
must be emitted, so this also manages that.

Note that this includes some additional rules that GCC does not, since
defining something as a MultiVersion function after a usage has been made illegal.

The only 'history rewriting' that happens is if a function is emitted before
it has been converted to a multiversion'ed function, at which point its name
needs to be changed.

Function templates and virtual functions are NOT yet supported (not supported
in GCC either).

Additionally, constructors/destructors are disallowed, but the former is 
planned.

llvm-svn: 322028
2018-01-08 21:34:17 +00:00
Carlo Bertolli 52978c3554 [OpenMP] Initial implementation of code generation for pragma 'target teams distribute parallel for' on host
https://reviews.llvm.org/D41709

This patch includes code generation and testing for offloading when target device is host.

llvm-svn: 321759
2018-01-03 21:12:44 +00:00
Reid Kleckner 06f19a0de0 [WinEH] Allow for multiple terminatepads
Fixes verifier errors with Windows EH and OpenMP, which injects a
terminate scope around parallel blocks.

Fixes PR35778

llvm-svn: 321676
2018-01-02 21:34:16 +00:00
Alexey Bataev a8a9153a37 [OPENMP] Support for -fopenmp-simd option with compilation of simd loops
only.

Added support for -fopenmp-simd option that allows compilation of
simd-based constructs without emission of OpenMP runtime calls.

llvm-svn: 321560
2017-12-29 18:07:07 +00:00
Stephan Bergmann d71ad177eb -fsanitize=vptr warnings on bad static types in dynamic_cast and typeid
...when such an operation is done on an object during con-/destruction.

This is the cfe part of a patch covering both cfe and compiler-rt.

Differential Revision: https://reviews.llvm.org/D40295

llvm-svn: 321519
2017-12-28 12:45:41 +00:00
Alexey Bataev d2202caeda [OPENMP] Support for `depend` clauses on `target data update`.
Added codegen for `depend` clauses on `target data update` directives.

llvm-svn: 321493
2017-12-27 17:58:32 +00:00
Abderrazek Zaafrani abb890b7be [AArch64] Enable fp16 data type for the Builtin for AArch64 only.
Differential Revision: https:://reviews.llvm.org/D41360

llvm-svn: 321301
2017-12-21 20:10:03 +00:00
Vedant Kumar 09b5bfdd85 [ubsan] Diagnose noreturn functions which return
Diagnose 'unreachable' UB when a noreturn function returns.

  1. Insert a check at the end of functions marked noreturn.

  2. A decl may be marked noreturn in the caller TU, but not marked in
     the TU where it's defined. To diagnose this scenario, strip away the
     noreturn attribute on the callee and insert check after calls to it.

Testing: check-clang, check-ubsan, check-ubsan-minimal, D40700

rdar://33660464

Differential Revision: https://reviews.llvm.org/D40698

llvm-svn: 321231
2017-12-21 00:10:25 +00:00
Krzysztof Parzyszek 5a6558382c [Hexagon] Intrinsic support for V62 and V65
llvm-svn: 320609
2017-12-13 19:56:03 +00:00
Alexey Bataev fbe17fb8a5 [OPENMP] Initial codegen for `target teams distribute simd` directive.
Host + generic device codegen for `target teams distribute simd`
directive.

llvm-svn: 320608
2017-12-13 19:45:06 +00:00
Alexey Bataev dfa430f694 [OPENMP] Initial codegen for `target teams distribute` directive.
Host + default devices codegen for `target teams distribute` directive.

llvm-svn: 320149
2017-12-08 15:03:50 +00:00
Vedant Kumar 36347d917f [ubsan] Use pass_object_size info in bounds checks
Teach UBSan's bounds check to opportunistically use pass_object_size
information to check array accesses.

rdar://33272922

llvm-svn: 320128
2017-12-08 01:51:47 +00:00
Dean Michael Berris 1a5b10d5b4 [XRay][clang] Introduce -fxray-always-emit-customevents
Summary:
The -fxray-always-emit-customevents flag instructs clang to always emit
the LLVM IR for calls to the `__xray_customevent(...)` built-in
function. The default behaviour currently respects whether the function
has an `[[clang::xray_never_instrument]]` attribute, and thus not lower
the appropriate IR code for the custom event built-in.

This change allows users calling through to the
`__xray_customevent(...)` built-in to always see those calls lowered to
the corresponding LLVM IR to lay down instrumentation points for these
custom event calls.

Using this flag enables us to emit even just the user-provided custom
events even while never instrumenting the start/end of the function
where they appear. This is useful in cases where "phase markers" using
__xray_customevent(...) can have very few instructions, must never be
instrumented when entered/exited.

Reviewers: rnk, dblaikie, kpw

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D40601

llvm-svn: 319388
2017-11-30 00:04:54 +00:00