Commit Graph

1044 Commits

Author SHA1 Message Date
Aaron Ballman 7c04eae204 Silence -Wparentheses warnings (and ran it through clang-format); NFC.
llvm-svn: 241582
2015-07-07 13:25:57 +00:00
Douglas Gregor e83b95641f Substitute type arguments into uses of Objective-C interface members.
When messaging a method that was defined in an Objective-C class (or
category or extension thereof) that has type parameters, substitute
the type arguments for those type parameters. Similarly, substitute
into property accesses, instance variables, and other references.

This includes general infrastructure for substituting the type
arguments associated with an ObjCObject(Pointer)Type into a type
referenced within a particular context, handling all of the
substitutions required to deal with (e.g.) inheritance involving
parameterized classes. In cases where no type arguments are available
(e.g., because we're messaging via some unspecialized type, id, etc.),
we substitute in the type bounds for the type parameters instead.

Example:

  @interface NSSet<T : id<NSCopying>> : NSObject <NSCopying>
  - (T)firstObject;
  @end

  void f(NSSet<NSString *> *stringSet, NSSet *anySet) {
    [stringSet firstObject]; // produces NSString*
    [anySet firstObject]; // produces id<NSCopying> (the bound)
  }

When substituting for the type parameters given an unspecialized
context (i.e., no specific type arguments were given), substituting
the type bounds unconditionally produces type signatures that are too
strong compared to the pre-generics signatures. Instead, use the
following rule:

  - In covariant positions, such as method return types, replace type
    parameters with “id” or “Class” (the latter only when the type
    parameter bound is “Class” or qualified class, e.g,
    “Class<NSCopying>”)
  - In other positions (e.g., parameter types), replace type
    parameters with their type bounds.
  - When a specialized Objective-C object or object pointer type
    contains a type parameter in its type arguments (e.g.,
    NSArray<T>*, but not NSArray<NSString *> *), replace the entire
    object/object pointer type with its unspecialized version (e.g.,
    NSArray *).

llvm-svn: 241543
2015-07-07 03:57:53 +00:00
Reid Kleckner 9fe7f2396b Revert "Revert 241171, 241187, 241199 (32-bit SEH)."
This reverts commit r241244, but restricts SEH support to Win64.

This way, Chromium builds will still fall back on TUs with SEH, and
Clang developers can work on this incrementally upstream while patching
this small predicate locally. It'll also make it easier to review small
fixes.

llvm-svn: 241533
2015-07-07 00:36:30 +00:00
Alexey Bataev 81c7ea0ec3 [OPENMP 4.0] Fixed codegen for 'cancellation point' construct.
Generate the next code for 'cancellation point':
if (__kmpc_cancellationpoint()) {
  __kmpc_cancel_barrier();
  <exit construct>;
}

llvm-svn: 241336
2015-07-03 09:56:58 +00:00
Akira Hatanaka 85365cd72a Attach attribute "trap-func-name" to call sites of llvm.trap and llvm.debugtrap.
This is needed to use clang's command line option "-ftrap-function" for LTO and
enable changing the trap function name on a per-call-site basis.

rdar://problem/21225723

Differential Revision: http://reviews.llvm.org/D10831

llvm-svn: 241306
2015-07-02 22:15:41 +00:00
Alexey Bataev 80909878ad [OPENMP 4.0] Initial support for 'omp cancel' construct.
Implemented parsing/sema analysis + (de)serialization.

llvm-svn: 241253
2015-07-02 11:25:17 +00:00
Nico Weber e4f974c6fb Revert 241171, 241187, 241199 (32-bit SEH).
It still doesn't produce quite the right code, test binaries built with this
enabled fail some tests.

llvm-svn: 241244
2015-07-02 06:10:53 +00:00
Alexey Bataev 0f34da12e4 [OPENMP 4.0] Codegen for 'cancellation point' directive.
The next code is generated for this construct:
```
if (__kmpc_cancellationpoint(ident_t *loc, kmp_int32 global_tid, kmp_int32 cncl_kind) != 0)
  <exit from outer innermost construct>;
```

llvm-svn: 241239
2015-07-02 04:17:07 +00:00
Reid Kleckner eb11c41900 [SEH] Delete the 32-bit IR lowering for __finally blocks and use x64
32-bit finally funclets are intended to be called both directly from the
parent function and indirectly from the EH runtime. Because we aren't
contorting LLVM's X86 prologue to match MSVC's, calling the finally
block directly passes in a different value of EBP than the one that the
runtime provides. We need an adapter thunk to adjust EBP to the expected
value. However, WinEHPrepare already has to solve this problem when
cleanups are not pre-outlined, so we can go ahead and rely on it rather
than duplicating work.

Now we only do the llvm.x86.seh.recoverfp dance for 32-bit SEH filter
functions.

llvm-svn: 241187
2015-07-01 21:00:00 +00:00
Reid Kleckner d0d9a1f63f [SEH] Add 32-bit lowering for SEH __try
This re-lands r236052 and adds support for __exception_code().

In 32-bit SEH, the exception code is not available in eax. It is only
available in the filter function, and now we arrange to load it and
store it into an escaped variable in the parent frame.

As a consequence, we have to disable the "catch i8* null" optimization
on 32-bit and always generate a filter function. We can re-enable the
optimization if we detect an __except block that doesn't use the
exception code, but this probably isn't worth optimizing.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D10852

llvm-svn: 241171
2015-07-01 17:10:10 +00:00
Alexey Bataev 6d4ed05830 [OPENMP 4.0] Initial support for 'omp cancellation point' construct.
Add parsing and sema analysis for 'omp cancellation point' directive.

llvm-svn: 241145
2015-07-01 06:57:41 +00:00
Justin Bogner bdff219439 CodeGen: Resize LifetimeExtendedCleanupHeader to avoid alignment issues
The LifetimeExtendedCleanupHeader is carefully fit into 32 bytes,
meaning that cleanups on the LifetimeExtendedCleanupStack are *always*
allocated at a misaligned address and cause undefined behaviour.

There are two ways to solve this - add padding after the header when
we allocated our cleanups, or just simplify the header and let it use
64 bits in the first place. I've opted for the latter, and added a
static assert to avoid the issue in the future.

llvm-svn: 241133
2015-07-01 00:59:27 +00:00
Peter Collingbourne e286b0e1f2 Fix use-after-free.
llvm-svn: 241121
2015-06-30 22:08:44 +00:00
Artem Belevich d21e5c6684 [CUDA] Implemented __nvvm_atom_*_gen_* builtins.
Integer variants are implemented as atomicrmw or cmpxchg instructions.
Atomic add for floating point (__nvvm_atom_add_gen_f()) is implemented
as a call to an overloaded @llvm.nvvm.atomic.load.add.f32.* LVVM
intrinsic.

Differential Revision: http://reviews.llvm.org/D10666

llvm-svn: 240669
2015-06-25 18:29:42 +00:00
Alexey Bataev d157d47062 Proper changing/restoring for CapturedStmtInfo, NFC.
Added special RAII class for proper values changing/restoring in CodeGenFunction::CapturedStmtInfo.

llvm-svn: 240517
2015-06-24 03:35:38 +00:00
Matt Arsenault 3ea39f9e78 AMDGPU: Fix places missed in rename
llvm-svn: 240148
2015-06-19 17:54:10 +00:00
Peter Collingbourne 6708c4a176 Implement diagnostic mode for -fsanitize=cfi*, -fsanitize=cfi-diag.
This causes programs compiled with this flag to print a diagnostic when
a control flow integrity check fails instead of aborting. Diagnostics are
printed using UBSan's runtime library.

The main motivation of this feature over -fsanitize=vptr is fidelity with
the -fsanitize=cfi implementation: the diagnostics are printed under exactly
the same conditions as those which would cause -fsanitize=cfi to abort the
program. This means that the same restrictions apply regarding compiling
all translation units with -fsanitize=cfi, cross-DSO virtual calls are
forbidden, etc.

Differential Revision: http://reviews.llvm.org/D10268

llvm-svn: 240109
2015-06-19 01:51:54 +00:00
Alexey Bataev c30dd2daf9 [OPENMP] Support for '#pragma omp taskgroup' directive.
Added parsing, sema analysis and codegen for '#pragma omp taskgroup' directive (OpenMP 4.0).
The code for directive is generated the following way:
#pragma omp taskgroup
<body>

void __kmpc_taskgroup(<loc>, thread_id);
<body>
void __kmpc_end_taskgroup(<loc>, thread_id);

llvm-svn: 240011
2015-06-18 12:14:09 +00:00
Alexey Bataev 3b5b5c492e [OPENMP] Add support for 'omp parallel for' directive.
Codegen for this directive is a combined codegen for 'omp parallel' region with 'omp for simd' region inside. Clauses are supported.

llvm-svn: 240006
2015-06-18 10:10:12 +00:00
Alexey Bataev 58e5bdb091 [OPENMP] Add support for 'omp for simd' directive.
Added codegen for combined 'omp for simd' directives, that is a combination of 'omp for' directive followed by 'omp simd' directive. Includes support for all clauses.

llvm-svn: 239990
2015-06-18 04:45:29 +00:00
Alexey Bataev cbdcbb7690 [OPENMP] Code reformatting for omp simd codegen, NFC.
llvm-svn: 239889
2015-06-17 07:45:51 +00:00
Alexey Bataev fc087ecc05 [OPENMP] Support lastprivate clause in omp simd directive.
Added codegen for lastprivate clauses within simd loop-based directives.

llvm-svn: 239813
2015-06-16 13:14:42 +00:00
Alexey Bataev ae05c29ab5 [OPENMP] Remove last iteration separation for loop-based constructs.
Previously the last iteration for simd loop-based OpenMP constructs were generated as a separate code. This feature is not required and codegen is simplified.

llvm-svn: 239810
2015-06-16 11:59:36 +00:00
Reid Kleckner 0b9bbbfc13 Revert "Re-land r236052, "[SEH] Add 32-bit lowering code for __try""
This reverts commit r239415. This was committed accidentally, LLVM isn't
ready for this.

llvm-svn: 239417
2015-06-09 17:49:42 +00:00
Reid Kleckner 65870442b3 Re-land r236052, "[SEH] Add 32-bit lowering code for __try"
This reverts r236167.

LLVM should be ready for this now.

llvm-svn: 239415
2015-06-09 17:47:50 +00:00
Nuno Lopes 1ba2d78b9a ubsan: Check for null pointers given to certain builtins, such
as memcpy, memset, memmove, and bzero.

Reviewed by: Richard Smith

Differential Revision: http://reviews.llvm.org/D9673

llvm-svn: 238657
2015-05-30 16:11:40 +00:00
Justin Bogner 20eb9d486c wip: Remove some unused functions
llvm-svn: 238538
2015-05-29 02:42:14 +00:00
Alexey Bataev d7589ffe1d [OPENMP] Fix codegen for ordered loop directives.
loops with ordered clause must be generated the same way as dynamic loops, but with static scheduleing.

llvm-svn: 237788
2015-05-20 13:12:48 +00:00
Alexey Bataev f0ab553fea [OPENMP] Fixed bug in atomic update/capture/write constructs.
Fixed a bug with codegen for destination atomic l-value with padding and junk in this padding bytes.

llvm-svn: 237422
2015-05-15 08:36:34 +00:00
Peter Collingbourne 3eea677f3a Unify sanitizer kind representation between the driver and the rest of the compiler.
No functional change.

Differential Revision: http://reviews.llvm.org/D9618

llvm-svn: 237055
2015-05-11 21:39:14 +00:00
Justin Bogner 65512647cc InstrProf: Cede ownership of createProfileWeights to CGF
The fact that PGO has a say in how these branch weights are determined
isn't interesting to most of CodeGen, so it makes more sense for this
API to be accessible via CodeGenFunction rather than CodeGenPGO.

llvm-svn: 236380
2015-05-02 05:00:55 +00:00
Reid Kleckner cb7a0a0562 Revert most of r236271, leaving only the datalayout change in lib/Basic/Targets.cpp
llvm-svn: 236274
2015-04-30 22:29:25 +00:00
Reid Kleckner af67602e14 Use 4 byte preferred aggregate alignment in datalayout on x86 Win32
llvm-svn: 236271
2015-04-30 22:13:05 +00:00
Reid Kleckner be9843ce54 Revert r236128, LLVM isn't falling back in the right way
llvm-svn: 236167
2015-04-29 21:55:21 +00:00
Reid Kleckner 0bb12a8981 Re-land r236052, the linker errors were fixed by LLVM r236123
Basic __finally blocks don't cause linker errors anymore (although they
are miscompiled).

llvm-svn: 236128
2015-04-29 17:17:17 +00:00
Nico Weber ea721b64df Revert r236052, it caused linker errors when building 32-bit applications.
llvm-svn: 236082
2015-04-29 03:08:32 +00:00
Reid Kleckner ddd40964f0 [SEH] Add 32-bit lowering code for __try
This is just the clang-side of 32-bit SEH. LLVM still needs work, and it
will determinstically fail to compile until it's feature complete.

On x86, all outlined handlers have no parameters, but they do implicitly
take the EBP value passed in and use it to address locals of the parent
frame. We model this with llvm.frameaddress(1).

This works (mostly), but __finally block inlining can break it. For now,
we apply the 'noinline' attribute. If we really want to inline __finally
blocks on 32-bit x86, we should teach the inliner how to untangle
frameescape and framerecover.

Promote the error diagnostic from codegen to sema. It now rejects SEH on
non-Windows platforms. LLVM doesn't implement SEH on non-x86 Windows
platforms, but there's nothing preventing it.

llvm-svn: 236052
2015-04-28 22:19:32 +00:00
Justin Bogner 66242d6c5e InstrProf: Stop using RegionCounter outside of CodeGenPGO (NFC)
The RegionCounter type does a lot of legwork, but most of it is only
meaningful within the implementation of CodeGenPGO. The uses elsewhere
in CodeGen generally just want to increment or read counters, so do
that directly.

llvm-svn: 235664
2015-04-23 23:06:47 +00:00
Alexey Bataev 5e018f9e29 [OPENMP] Codegen for 'atomic capture'.
Adds codegen for 'atomic capture' constructs with the following forms of expressions/statements:

v = x binop= expr;
v = x++;
v = ++x;
v = x--;
v = --x;
v = x = x binop expr;
v = x = expr binop x;
{v = x; x = binop= expr;}
{v = x; x++;}
{v = x; ++x;}
{v = x; x--;}
{v = x; --x;}
{x = x binop expr; v = x;}
{x binop= expr; v = x;}
{x++; v = x;}
{++x; v = x;}
{x--; v = x;}
{--x; v = x;}
{x = x binop expr; v = x;}
{x = expr binop x; v = x;}
{v = x; x = expr;}
If x and expr are integer and binop is associative or x is a LHS in a RHS of the assignment expression, and atomics are allowed for type of x on the target platform atomicrmw instruction is emitted.
Otherwise compare-and-swap sequence is emitted.
Update of 'v' is not required to be be atomic with respect to the read or write of the 'x'.

bb:
...
atomic load <x>
cont:
<expected> = phi [ <x>, label %bb ], [ <new_failed>, %cont ]
<desired> = <expected> binop <expr>
<res> = cmpxchg atomic &<x>, desired, expected
<new_failed> = <res>.field1;
br <res>field2, label %exit, label %cont
exit:
atomic store <old/new x>, <v>
...
Differential Revision: http://reviews.llvm.org/D9049

llvm-svn: 235573
2015-04-23 06:35:10 +00:00
David Majnemer dc012fa266 Revert "Revert r234581, it might have caused a few miscompiles in Chromium."
This reverts commit r234700.  It turns out that the lifetime markers
were not the cause of Chromium failing but a bug which was uncovered by
optimizations exposed by the markers.

llvm-svn: 235553
2015-04-22 21:38:15 +00:00
Alexey Bataev 98eb6e3d41 [OPENMP] Codegen for 'ordered' directive.
Add codegen for 'ordered' directive:

__kmpc_ordered(ident_t *, gtid);
<associated statement>;
__kmpc_end_ordered(ident_t *, gtid);
Also for 'for' directives with the dynamic scheduling and an 'ordered' clause added a call to '__kmpc_dispatch_fini_(4|8)[u]()' function after increment expression for loop control variable:

while(__kmpc_dispatch_next(&LB, &UB)) {
  idx = LB;
  while (idx <= UB) { BODY; ++idx;
    __kmpc_dispatch_fini_(4|8)[u](); // For ordered loops only.
  } // inner loop
}
Differential Revision: http://reviews.llvm.org/D9070

llvm-svn: 235496
2015-04-22 11:15:40 +00:00
Alexey Bataev f56f98c925 [OPENMP] Codegen for 'copyin' clause in 'parallel' directive.
Emits the following code for the clause at the beginning of the outlined function for implicit threads:

if (<not a master thread>) {
  ...
  <thread local copy of var> = <master thread local copy of var>;
  ...
}
<sync point>;
Checking for a non-master thread is performed by comparing of the address of the thread local variable with the address of the master's variable. Master thread always uses original variables, so you always know the address of the variable in the master thread.
Differential Revision: http://reviews.llvm.org/D9026

llvm-svn: 235075
2015-04-16 05:39:01 +00:00
Alexey Bataev 38e8953352 [OPENMP] Codegen for 'lastprivate' clause in 'for' directive.
#pragma omp for lastprivate(<var>)
for (i = a; i < b; ++b)
  <BODY>;

This construct is translated into something like:

  <last_iter> = alloca i32
  <lastprivate_var> = alloca <type>
  <last_iter> = 0
  ; No initializer for simple variables or a default constructor is called for objects.
  ; For arrays perform element by element initialization by the call of the default constructor.
  ...
  OMP_FOR_START(...,<last_iter>, ..); sets <last_iter> to 1 if this is the last iteration.
  <BODY>
  ...
  OMP_FOR_END
  if (<last_iter> != 0) {
    <var> = <lastprivate_var> ; Update original variable with the lastprivate value.
  }
  call __kmpc_cancel_barrier() ; an implicit barrier to avoid possible data race.

Differential Revision: http://reviews.llvm.org/D8658

llvm-svn: 235074
2015-04-16 04:54:05 +00:00
Alexey Bataev 69c62a9bdb [OPENMP] Codegen for 'firstprivate' clause in 'for' directive.
Adds proper codegen for 'firstprivate' clause in for directive. Initially codegen for 'firstprivate' clause was implemented for 'parallel' directive only.
Also this patch emits sync point only after initialization of firstprivate variables, not all private variables. This sync point is not required for privates, lastprivates etc., only for initialization of firstprivate variables.
Differential Revision: http://reviews.llvm.org/D8660

llvm-svn: 234978
2015-04-15 04:52:20 +00:00
Reid Kleckner ebaf28d13d Reland r234613 (and follow-ups 234614, 234616, 234618)
The frameescape intrinsic cannot be inlined, so I fixed the inliner in
r234937. This should address PR23216.

llvm-svn: 234942
2015-04-14 20:59:00 +00:00
Alexey Bataev 420d45b2dd [OPENMP] Fixed codegen for arrays in 'copyprivate' clause.
Fixed a bug with codegen of variables with array types specified in 'copyprivate' clause of 'single' directive.
Differential Revision: http://reviews.llvm.org/D8914

llvm-svn: 234856
2015-04-14 05:11:24 +00:00
Alexey Bataev 68adb7da1a [OPENMP] Initial codegen for 'parallel sections' directive.
Emits code for outlined 'parallel' directive with the implicitly inlined 'sections' directive:

...
call __kmpc_fork_call(..., outlined_function, ...);
...

define internal void outlined_function(...) {
    <code for implicit sections directive>;
}
Differential Revision: http://reviews.llvm.org/D8997

llvm-svn: 234849
2015-04-14 03:29:22 +00:00
Nico Weber ad108337cf Revert r234613 (and follow-ups 234614, 234616, 234618), it caused PR23216.
llvm-svn: 234789
2015-04-13 20:04:22 +00:00
Nico Weber f2a39a7b4e Revert r234786, it contained a bunch of stuff I did not mean to commit.
llvm-svn: 234787
2015-04-13 20:03:03 +00:00
Nico Weber b31abb05fb Revert r234613 (and follow-ups 234614, 234616, 234618), it caused PR23216.
llvm-svn: 234786
2015-04-13 20:01:20 +00:00
Nico Weber 1c565c31b1 Revert r234581, it might have caused a few miscompiles in Chromium.
If the revert helps, I'll get a repro this Monday.  Else I'll put the change
back in.

llvm-svn: 234700
2015-04-11 23:51:38 +00:00
Reid Kleckner 11859afd5f [SEH] Re-land r234532, but use internal linkage for all SEH helpers
Even though these symbols are in a comdat group, the Microsoft linker
really wants them to have internal linkage.

I'm planning to tweak the mangling in a follow-up change. This is a
straight revert with a 1-line fix.

llvm-svn: 234613
2015-04-10 17:34:52 +00:00
Alexey Bataev 794ba0dcb7 [OPENMP] Codegen for 'reduction' clause in 'parallel' directive.
Emit a code for reduction clause. Next code should be emitted for reductions:

static kmp_critical_name lock = { 0 };

void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
  ...
  *(Type<i> *)lhs[i] = RedOp<i>(*(Type<i> *)lhs[i], *(Type<i> *)rhs[i]);
  ...
}

... void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n> - 1]};
switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList), RedList, reduce_func, &<lock>)) {
case 1:
  ...
  <LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
  ...
  __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
  break;
case 2:
  ...
  Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
  ...
  break;
default:
  ;
}
Reduction variables are a kind of a private variables, they have private copies, but initial values are chosen in accordance with the reduction operation.

Differential Revision: http://reviews.llvm.org/D8915

llvm-svn: 234583
2015-04-10 10:43:45 +00:00
Arnaud A. de Grandmaison 047a686d53 Remove threshold for inserting lifetime markers for named temporaries
Now that TailRecursionElimination has been fixed with r222354, the
threshold on size for lifetime marker insertion can be removed. This
only affects named temporary though, as the patch for unnamed temporaries
is still in progress.

My previous commit (r222993) was not handling debuginfo correctly, but
this could only be seen with some asan tests. Basically, lifetime markers
are just instrumentation for the compiler's usage and should not affect
debug information; however, the cleanup infrastructure was assuming it
contained only destructors, i.e. actual code to be executed, and was
setting the breakpoint for the end of the function to the closing '}', and
not the return statement, in order to show some destructors have been
called when leaving the function. This is wrong when the cleanups are only
lifetime markers, and this is now fixed.

llvm-svn: 234581
2015-04-10 10:13:52 +00:00
Alexey Bataev 6f1ffc069b [OPENMP] Refactoring of codegen for OpenMP directives.
Refactored API of OpenMPRuntime for compatibility with combined directives.
Differential Revision: http://reviews.llvm.org/D8859

llvm-svn: 234564
2015-04-10 04:50:10 +00:00
Nico Weber bd51a6a99f Revert r234532 for a bit, it very likely caused http://crbug.com/475768
llvm-svn: 234563
2015-04-10 04:33:03 +00:00
Reid Kleckner 0dbecf2b78 [SEH] Outline finally blocks using the new variable capture support
WinEHPrepare was going to have to pattern match the control flow merge
and split that the old lowering used, and that wasn't really feasible.

Now we can teach WinEHPrepare to pattern match this, which is much
simpler:
  %fp = call i8* @llvm.frameaddress(i32 0)
  call void @func(iN [01], i8* %fp)

This prototype happens to match the prototype used by the Win64 SEH
personality function, so this is really simple.

llvm-svn: 234532
2015-04-09 20:37:24 +00:00
Reid Kleckner 31a1bb0c14 Reland "[SEH] Implement filter capturing in CodeGen"
The test should be fixed. It was failing in NDEBUG builds due to a
missing '*' character in a regex. In asserts builds, the pattern matched
a single digit value, which became a double digit value in NDEBUG
builds. Go figure.

This reverts commit r234261.

llvm-svn: 234447
2015-04-08 22:23:48 +00:00
Daniel Jasper 303c3ac925 Revert "[SEH] Implement filter capturing in CodeGen"
Test fails:
http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_check/3182/

llvm-svn: 234306
2015-04-07 10:07:47 +00:00
Reid Kleckner 0ada50f17f [SEH] Implement filter capturing in CodeGen
While capturing filters aren't very common, we'd like to outline
__finally blocks in the frontend to simplify -O0 EH preparation and
reduce code size. Finally blocks are usually have captures, and this is
the first step towards that.

Currently we don't support capturing 'this' or VLAs.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D8825

llvm-svn: 234261
2015-04-06 23:51:44 +00:00
David Blaikie 1ed728c499 [opaque pointer type] More GEP API migrations
Looks like the VTable code in particular will need some work to pass
around the pointee type explicitly.

llvm-svn: 234128
2015-04-05 22:45:47 +00:00
David Blaikie fb901c7abf [opaque pointer type] more GEP API migrations
llvm-svn: 234097
2015-04-04 15:12:29 +00:00
Ulrich Weigand 3a610ebf1e [SystemZ] Support transactional execution on zEC12
The zEC12 provides the transactional-execution facility.  This is exposed
to users via a set of builtin routines on other compilers.  This patch
adds clang support to enable those builtins.  In partciular, the patch:

- enables the transactional-execution feature by default on zEC12
- allows to override presence of that feature via the -mhtm/-mno-htm options
- adds a predefined macro __HTM__ if the feature is enabled
- adds support for the transactional-execution GCC builtins
- adds Sema checking to verify the __builtin_tabort abort code
- adds the s390intrin.h header file (for GCC compatibility)
- adds s390 sections to the htmintrin.h and htmxlintrin.h header files

Since this is first use of target-specific intrinsics on the platform,
the patch creates the include/clang/Basic/BuiltinsSystemZ.def file and
hooks it up in TargetBuiltins.h and lib/Basic/Targets.cpp.

An associated LLVM patch adds the required LLVM IR intrinsics.

For reference, the transactional-execution instructions are documented
in the z/Architecture Principles of Operation for the zEC12:
http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/download/DZ9ZR009.pdf
The associated builtins are documented in the GCC manual:
http://gcc.gnu.org/onlinedocs/gcc/S_002f390-System-z-Built-in-Functions.html
The htmxlintrin.h intrinsics provided for compatibility with the IBM XL
compiler are documented in the "z/OS XL C/C++ Programming Guide".

llvm-svn: 233804
2015-04-01 12:54:25 +00:00
Alexey Bataev b4505a7229 [OPENMP] Codegen for 'atomic update' construct.
Adds atomic update codegen for the following forms of expressions:

x binop= expr;
x++;
++x;
x--;
--x;
x = x binop expr;
x = expr binop x;
If x and expr are integer and binop is associative or x is a LHS in a RHS of the assignment expression, and atomics are allowed for type of x on the target platform atomicrmw instruction is emitted.
Otherwise compare-and-swap sequence is emitted:

bb:
...
atomic load <x>
cont:
<expected> = phi [ <x>, label %bb ], [ <new_failed>, %cont ]
<desired> = <expected> binop <expr>
<res> = cmpxchg atomic &<x>, desired, expected
<new_failed> = <res>.field1;
br <res>field2, label %exit, label %cont
exit:
...

Differential Revision: http://reviews.llvm.org/D8536

llvm-svn: 233513
2015-03-30 05:20:59 +00:00
Alexey Bataev a63048e4fd [OPENMP] Codegen for 'copyprivate' clause ('single' directive).
If there is at least one 'copyprivate' clause is associated with the single directive, the following code is generated:

```
i32 did_it = 0;                                  \\ for 'copyprivate' clause
if(__kmpc_single(ident_t *, gtid)) {
  SingleOpGen();
  __kmpc_end_single(ident_t *, gtid);
  did_it = 1;                                    \\ for 'copyprivate' clause
}
<copyprivate_list>[0] = &var0;
...
<copyprivate_list>[n] = &varn;
call __kmpc_copyprivate(ident_t *, gtid, <copyprivate_list_size>,
                        <copyprivate_list>, <copy_func>, did_it);

...

void<copy_func>(void *LHSArg, void *RHSArg) {
  Dst = (void * [n])(LHSArg);
  Src = (void * [n])(RHSArg);
  Dst[0] = Src[0];
  ... Dst[n] = Src[n];
}
```
All list items from all 'copyprivate' clauses are gathered into single <copyprivate list> (<copyprivate_list_size> is a size in bytes of this list) and <copy_func> is used to propagate values of private or threadprivate variables from the 'single' region to other implicit threads from outer 'parallel' region.
Differential Revision: http://reviews.llvm.org/D8410

llvm-svn: 232932
2015-03-23 06:18:07 +00:00
Peter Collingbourne d2926c91d5 Implement bad cast checks using control flow integrity information.
This scheme checks that pointer and lvalue casts are made to an object of
the correct dynamic type; that is, the dynamic type of the object must be
a derived class of the pointee type of the cast. The checks are currently
only introduced where the class being casted to is a polymorphic class.

Differential Revision: http://reviews.llvm.org/D8312

llvm-svn: 232241
2015-03-14 02:42:25 +00:00
Benjamin Kramer 7f1f6b5370 Disambiguate call for GCC.
llvm-svn: 232122
2015-03-12 23:46:55 +00:00
Benjamin Kramer 51680bccda CodeGen: Base the conditional cleanup machinery on variadic templates
This is complicated by the fact that we can't simply use side-effecting
calls in an argument list without losing all guarantees about the order
they're emitted. To keep things deterministic we use tuples and brace
initialization, which thankfully guarantees evaluation order.

No functionality change intended.

llvm-svn: 232121
2015-03-12 23:41:40 +00:00
Alexey Bataev 2df54a07bf [OPENMP] Initial codegen for 'omp sections' and 'omp section' directives.
If only one section is found in the sections region, it is emitted just like single region.
Otherwise it is emitted as a static non-chunked loop.

#pragma omp sections
{
#pragma omp section
  {1}
  ...
  #pragma omp section
  {n}
}
is translated to something like

i32 <iter_var>
i32 <last_iter> = 0
i32 <lower_bound> = 0
i32 <upper_bound> = n-1
i32 <stride> = 1
call void @__kmpc_for_static_init_4(<loc>, i32 <gtid>, i32 34/*static non-chunked*/, i32* <last_iter>, i32* <lower_bound>, i32* <upper_bound>, i32* <stride>, i32 1/*increment always 1*/, i32 1/*chunk always 1*/)
<upper_bound> = min(<upper_bound>, n-1)
<iter_var> = <lb>
check:
br <iter_var> <= <upper_bound>, label cont, label exit
continue:
switch (IV) {
  case 0:
  {1};
  break;
  ...
  case <NumSection> - 1:
  {n};
  break;
  }
  ++<iter_var>
  br label check
  exit:
  call void @__kmpc_for_static_fini(<loc>, i32 <gtid>)
Differential Revision: http://reviews.llvm.org/D8244

llvm-svn: 232021
2015-03-12 08:53:29 +00:00
David Majnemer 7c23707174 MS ABI: Implement support for throwing a C++ exception
Throwing a C++ exception, under the MS ABI, is implemented using three
components:
- ThrowInfo structure which contains information like CV qualifiers,
  what destructor to call and a pointer to the CatchableTypeArray.
- In a significant departure from the Itanium ABI, copying by-value
  occurs in the runtime and not at the catch site.  This means we need
  to enumerate all possible types that this exception could be caught as
  and encode the necessary information to convert from the exception
  object's type to the catch handler's type.  This includes complicated
  derived to base conversions and the execution of copy-constructors.

N.B. This implementation doesn't support the execution of a
copy-constructor from within the runtime for now.  Adding support for
that functionality is quite difficult due to things like default
argument expressions which may evaluate arbitrary code hiding in the
copy-constructor's parameters.

Differential Revision: http://reviews.llvm.org/D8066

llvm-svn: 231328
2015-03-05 00:46:22 +00:00
Alexey Bataev 8cbe0a6b62 [OPENMP] Fixed codegen for directives without function outlining.
Fixed crash on codegen for directives like 'omp for', 'omp single' etc. inside of the 'omp parallel', 'omp task' etc. regions.

llvm-svn: 230621
2015-02-26 10:27:34 +00:00
Peter Collingbourne a4ccff3281 Implement Control Flow Integrity for virtual calls.
This patch introduces the -fsanitize=cfi-vptr flag, which enables a control
flow integrity scheme that checks that virtual calls take place using a vptr of
the correct dynamic type. More details in the new docs/ControlFlowIntegrity.rst
file.

It also introduces the -fsanitize=cfi flag, which is currently a synonym for
-fsanitize=cfi-vptr, but will eventually cover all CFI checks implemented
in Clang.

Differential Revision: http://reviews.llvm.org/D7424

llvm-svn: 230055
2015-02-20 20:30:56 +00:00
Aaron Ballman abc1892057 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition.
llvm-svn: 229339
2015-02-15 22:54:08 +00:00
Aaron Ballman 673476684e Removing LLVM_EXPLICIT, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition.
llvm-svn: 229336
2015-02-15 22:00:28 +00:00
David Majnemer a5b195a1dc Revert "Revert r229082 for a bit, it caused PR22577."
This reverts commit r229123.  It was a red herring, the bug was present
without r229082.

llvm-svn: 229205
2015-02-14 01:35:12 +00:00
Nico Weber 7ce96b853d Revert r229082 for a bit, it caused PR22577.
llvm-svn: 229123
2015-02-13 16:27:00 +00:00
David Majnemer abc482effc MS ABI: Implement /volatile:ms
The /volatile:ms semantics turn volatile loads and stores into atomic
acquire and release operations.  This distinction is important because
volatile memory operations do not form a happens-before relationship
with non-atomic memory.  This means that a volatile store is not
sufficient for implementing a mutex unlock routine.

Differential Revision: http://reviews.llvm.org/D7580

llvm-svn: 229082
2015-02-13 07:55:47 +00:00
Reid Kleckner 11c033e8aa SEH: Use the SEHTryEpilogueStack instead of a separate bool
We don't need a bool to track this now that we have a stack for it.

llvm-svn: 228982
2015-02-12 23:40:45 +00:00
Nico Weber 5779f84000 [ms] Implement codegen for __leave.
Reviewed at http://reviews.llvm.org/D7575

llvm-svn: 228977
2015-02-12 23:16:11 +00:00
Richard Smith 527473df0d Fix typoo.
llvm-svn: 228963
2015-02-12 21:23:20 +00:00
Nico Weber 1bebad1b86 Wrap to 80 columns. No behavior change.
llvm-svn: 228880
2015-02-11 22:33:32 +00:00
Reid Kleckner a593000f01 Add the 'noinline' attribute to call sites within __try bodies
LLVM doesn't support non-call exceptions, so inlining makes it harder to
catch such asynchronous exceptions.

llvm-svn: 228876
2015-02-11 21:40:48 +00:00
Reid Kleckner e7b3f7c70d Emit landing pads for SEH even if nounwind is present
Disabling exceptions applies nounwind to lots of functions. SEH catches
asynch exceptions, so emit the landing pad anyway.

llvm-svn: 228769
2015-02-11 00:00:21 +00:00
Reid Kleckner aca01db706 Implement IRGen for SEH __finally and AbnormalTermination
Previously we would simply double-emit the body of the __finally block,
but that doesn't work when it contains any kind of Decl, which we can't
double emit.

This fixes that by emitting the block once and branching into a shared
code region and then branching back out.

llvm-svn: 228222
2015-02-04 22:37:07 +00:00
David Blaikie 4d52443c0e DebugInfo: Attribute cleanup code to the end of the scope, not the end of the function.
Now if you break on a dtor and go 'up' in your debugger (or you get an
asan failure in a dtor) during an exception unwind, you'll have more
context. Instead of all dtors appearing to be called from the '}' of the
function, they'll be attributed to the end of the scope of the variable,
the same as the non-exceptional dtor call.

This doesn't /quite/ remove all uses of CurEHLocation (which might be
nice to remove, for a few reasons) - it's still used to choose the
location for some other work in the landing pad. It'd be nice to
attribute that code to the same location as the exception calls within
the block and to remove CurEHLocation.

llvm-svn: 228181
2015-02-04 19:47:54 +00:00
David Majnemer fd1e739a44 CodeGen: Copy-ctorm must obey the destination's alignment requirement
We would synthesize memcpy intrinsics when emitting calls to trivial C++
constructors but we wouldn't take into account the alignment of the
destination.

llvm-svn: 228061
2015-02-03 23:04:06 +00:00
Alexander Musman df7a8e2bc8 Support ‘omp for’ with static chunked schedule kind.
Differential Revision: http://reviews.llvm.org/D7006

llvm-svn: 226795
2015-01-22 08:49:35 +00:00
Reid Kleckner 1d59f99f5c Initial support for Win64 SEH IR emission
The lowering looks a lot like normal EH lowering, with the exception
that the exceptions are caught by executing filter expression code
instead of matching typeinfo globals. The filter expressions are
outlined into functions which are used in landingpad clauses where
typeinfo would normally go.

Major aspects that still need work:
- Non-call exceptions in __try bodies won't work yet. The plan is to
  outline the __try block in the frontend to keep things simple.
- Filter expressions cannot use local variables until capturing is
  implemented.
- __finally blocks will not run after exceptions. Fixing this requires
  work in the LLVM SEH preparation pass.

The IR lowering looks like this:

// C code:
bool safe_div(int n, int d, int *r) {
  __try {
    *r = normal_div(n, d);
  } __except(_exception_code() == EXCEPTION_INT_DIVIDE_BY_ZERO) {
    return false;
  }
  return true;
}

; LLVM IR:
define i32 @filter(i8* %e, i8* %fp) {
  %ehptrs = bitcast i8* %e to i32**
  %ehrec = load i32** %ehptrs
  %code = load i32* %ehrec
  %matches = icmp eq i32 %code, i32 u0xC0000094
  %matches.i32 = zext i1 %matches to i32
  ret i32 %matches.i32
}

define i1 zeroext @safe_div(i32 %n, i32 %d, i32* %r) {
  %rr = invoke i32 @normal_div(i32 %n, i32 %d)
      to label %normal unwind to label %lpad

normal:
  store i32 %rr, i32* %r
  ret i1 1

lpad:
  %ehvals = landingpad {i8*, i32} personality i32 (...)* @__C_specific_handler
      catch i8* bitcast (i32 (i8*, i8*)* @filter to i8*)
  %ehptr = extractvalue {i8*, i32} %ehvals, i32 0
  %sel = extractvalue {i8*, i32} %ehvals, i32 1
  %filter_sel = call i32 @llvm.eh.seh.typeid.for(i8* bitcast (i32 (i8*, i8*)* @filter to i8*))
  %matches = icmp eq i32 %sel, %filter_sel
  br i1 %matches, label %eh.except, label %eh.resume

eh.except:
  ret i1 false

eh.resume:
  resume
}

Reviewers: rjmccall, rsmith, majnemer

Differential Revision: http://reviews.llvm.org/D5607

llvm-svn: 226760
2015-01-22 01:36:17 +00:00
David Blaikie 835afb205f DebugInfo: Remove forced column-info workaround for inlined calls
This workaround was to provide unique call sites to ensure LLVM's inline
debug info handling would properly unique two calls to the same function
on the same line. Instead, this has now been fixed in LLVM (r226736) and
the workaround here can be removed.

Originally committed in r176895, but this isn't a straight revert due to
all the changes since then. I just searched for anything ForcedColumn*
related and removed them.

We could test this - but it didn't strike me as terribly valuable once
we're no longer adding this workaround everything just works as expected
& it's no longer a special case to test for.

llvm-svn: 226738
2015-01-21 23:08:17 +00:00
David Blaikie a0a1a8726f Add comment after API changes in r225090
Code review suggestion by Eric Christopher.

llvm-svn: 226395
2015-01-18 02:48:07 +00:00
David Blaikie 66e4197f07 Reapply r225000 (reverted in r225555): DebugInfo: Generalize debug info location handling (and follow-up commits).
Several pieces of code were relying on implicit debug location setting
which usually lead to incorrect line information anyway. So I've fixed
those (in r225955 and r225845) separately which should pave the way for
this commit to be cleanly reapplied.

The reason these implicit dependencies resulted in crashes with this
patch is that the debug location would no longer implicitly leak from
one place to another, but be set back to invalid. Once a call with
no/invalid location was emitted, if that call was ever inlined it could
produce invalid debugloc chains and assert during LLVM's codegen.

There may be further cases of such bugs in this patch - they're hard to
flush out with regression testing, so I'll keep an eye out for reports
and investigate/fix them ASAP if they come up.

Original commit message:

Reapply "DebugInfo: Generalize debug info location handling"

Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).

Recommitted in r224941 and reverted in r224970 after it caused a crash
when building compiler-rt. Looks to be due to this change zeroing out
the debug location when emitting default arguments (which were meant to
inherit their outer expression's location) thus creating call
instructions without locations - these create problems for inlining and
must not be created. That is fixed and tested in this version of the
change.

Original commit message:

This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 225956
2015-01-14 07:38:27 +00:00
David Blaikie f142580dea Sink a parameter into the callee since it's always the same expression in terms of another parameter
llvm-svn: 225856
2015-01-14 00:04:42 +00:00
David Blaikie f353d3ecd0 Revert "DebugInfo: Generalize debug info location handling" and related commits
This reverts commit r225000, r225021, r225083, r225086, r225090.

The root change (r225000) still has several issues where it's caused
calls to be emitted without debug locations. This causes assertion
failures if/when those calls are inlined.

I'll work up some test cases and fixes before recommitting this.

llvm-svn: 225555
2015-01-09 23:00:28 +00:00
David Blaikie b9a23c9155 DebugInfo: Provide a less subtle way to set the debug location of simple ret instructions
un-XFAILing the test XFAIL'd in r225086 after it regressed in r225083.

llvm-svn: 225090
2015-01-02 22:07:26 +00:00
David Blaikie 84fe79cfc3 Reapply "DebugInfo: Generalize debug info location handling"
Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).

Recommitted in r224941 and reverted in r224970 after it caused a crash
when building compiler-rt. Looks to be due to this change zeroing out
the debug location when emitting default arguments (which were meant to
inherit their outer expression's location) thus creating call
instructions without locations - these create problems for inlining and
must not be created. That is fixed and tested in this version of the
change.

Original commit message:

This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 225000
2014-12-30 19:39:33 +00:00
David Blaikie 608a24501c Revert "DebugInfo: Generalize debug info location handling"
Asserting when building compiler-rt when using a GCC host compiler.
Reverting while I investigate.

This reverts commit r224941.

llvm-svn: 224970
2014-12-29 23:49:00 +00:00
David Blaikie 3945d1bd99 Reapply "DebugInfo: Generalize debug info location handling"
Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).

Original commit message:

This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 224941
2014-12-29 18:18:45 +00:00
Alexey Bataev 7cb1789011 Fix for PR21915: assert on multidimensional VLA in function arguments.
Fixed assertion on type checking for arguments and parameters on function call if arguments are pointers to VLA
Differential Revision: http://reviews.llvm.org/D6655

llvm-svn: 224504
2014-12-18 06:54:53 +00:00
David Blaikie 06b2c54db9 Revert "DebugInfo: Generalize debug info location handling"
Fails an ASan bootstrap - I'll try to reproduce locally & sort that out
before recommitting.

This reverts commit r224385.

llvm-svn: 224441
2014-12-17 18:02:04 +00:00
David Blaikie bf22a4eaee DebugInfo: Generalize debug info location handling
This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 224385
2014-12-16 22:49:17 +00:00