Commit Graph

1490 Commits

Author SHA1 Message Date
Reid Kleckner
1808c02c15 Re-land r359250, [COFF] Statically link certain runtime library functions
Reverts the revert of r359251, this time with fixed tests.

Differential Revision: https://reviews.llvm.org/D55229

llvm-svn: 359513
2019-04-29 23:05:47 +00:00
Reid Kleckner
1be5369a0c Revert [COFF] Statically link certain runtime library functions
This reverts r359250 (git commit 4730604bd3)

The newly added test should use -cc1 and -emit-llvm and there are other
test failures that need fixing.

llvm-svn: 359251
2019-04-25 23:30:41 +00:00
Reid Kleckner
4730604bd3 [COFF] Statically link certain runtime library functions
Statically link certain runtime library functions for MSVC/GNU Windows
environments. This is consistent with MSVC behavior.

Fixes LNK4286 and LNK4217 warnings from link.exe when linking the static
CRT:
  LINK : warning LNK4286: symbol '__std_terminate' defined in 'libvcruntime.lib(ehhelpers.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.asan_noinst_test.cc.x86_64-calls.o'
  LINK : warning LNK4286: symbol '__std_terminate' defined in 'libvcruntime.lib(ehhelpers.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.asan_test_main.cc.x86_64-calls.o'
  LINK : warning LNK4217: symbol '_CxxThrowException' defined in 'libvcruntime.lib(throw.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.gtest-all.cc.x86_64-calls.o' in function '"int `public: static class UnitTest::GetInstance * __cdecl testing::UnitTest::GetInstance(void)'::`1'::dtor$5" (?dtor$5@?0??GetInstance@UnitTest@testing@@SAPEAV12@XZ@4HA)'

Reviewers: mstorsjo, efriedma, TomTan, compnerd, smeenai, mgrang

Subscribers: abdulras, theraven, smeenai, pcc, mehdi_amini, javed.absar, inglorion, kristof.beyls, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D55229

llvm-svn: 359250
2019-04-25 23:04:20 +00:00
Fangrui Song
899d13926d Use llvm::stable_sort
llvm-svn: 359098
2019-04-24 14:43:05 +00:00
Scott Linder
fb59fef7dc Move setTargetAttributes after setGVProperties in SetFunctionAttributes
AMDGPU currently relies on global properties being set before
setTargetProperties is called. Existing targets like MIPS which rely on
setTargetProperties do not rely on the current behavior, so this patch
moves the call later in SetFunctionAttributes.

Differential Revision: https://reviews.llvm.org/D60967

llvm-svn: 359039
2019-04-23 21:50:11 +00:00
Anton Afanasyev
d880de2d19 Adds -ftime-trace option to clang that produces Chrome chrome://tracing compatible JSON profiling output dumps.
This change adds hierarchical "time trace" profiling blocks that can be visualized in Chrome, in a "flame chart" style. Each profiling block can have a "detail" string that for example indicates the file being processed, template name being instantiated, function being optimized etc.

This is taken from GitHub PR: https://github.com/aras-p/llvm-project-20170507/pull/2

Patch by Aras Pranckevičius.

Differential Revision: https://reviews.llvm.org/D58675

llvm-svn: 357340
2019-03-30 08:42:48 +00:00
Peter Collingbourne
d1c5b28c2a IRGen: Remove StructorType; thread GlobalDecl through more code. NFCI.
This should make it easier to add more structor variants.

Differential Revision: https://reviews.llvm.org/D59724

llvm-svn: 356822
2019-03-22 23:05:10 +00:00
Alexey Bataev
c56872589f [OPENMP]Codegen support for allocate directive on global variables.
For the global variables the allocate directive must specify only the
predefined allocator. This allocator must be translated into the correct
form of the address space for the targets that support different address
spaces.

llvm-svn: 356702
2019-03-21 19:35:27 +00:00
Jason Liu
a03ae73c29 Add XCOFF triple object format type for AIX
This patch adds an XCOFF triple object format type into LLVM.
This XCOFF triple object file type will be used later by object file and assembly generation for the AIX platform.

Differential Revision: https://reviews.llvm.org/D58930

llvm-svn: 355989
2019-03-12 22:01:10 +00:00
Alexey Bataev
25ed0c07c1 [OPENMP 5.0]Add initial support for 'allocate' directive.
Added parsing/sema analysis/serialization/deserialization support for
'allocate' directive.

llvm-svn: 355614
2019-03-07 17:54:44 +00:00
Rong Xu
39f6d7e616 [PGO] Use the explicit parameter in ProfileSummary API. NFC
Use the explicit parameter in setProfileSummary() and getSummary().
This is a follow-up of r355131.

llvm-svn: 355209
2019-03-01 17:50:20 +00:00
Yaxun Liu
e739ac0e25 [HIP] change kernel stub name
Add .stub to kernel stub function name so that it is different from kernel
name in device code. This is necessary to let debugger find correct symbol
for kernel.

Differential Revision: https://reviews.llvm.org/D58518

llvm-svn: 354948
2019-02-27 02:02:52 +00:00
Michael Liao
0ee7bd4ac5 [CodeGen] Fix string literal address space casting.
Summary:
- If a string literal is reused directly, need to add necessary address
  space casting if the target requires that.

Reviewers: yaxunl

Subscribers: jvesely, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58509

llvm-svn: 354610
2019-02-21 19:40:20 +00:00
Yaxun Liu
c18e9ecd4f [CUDA][HIP] Use device side kernel and variable names when registering them
__hipRegisterFunction and __hipRegisterVar need to accept device side kernel and variable names
so that HIP runtime can associate kernel stub functions in host code with kernel symbols in fat binaries,
and associate shadow variables in host code with device variables in fat binaries.

Currently, clang assumes kernel functions and device variables have the same name as the kernel
stub functions and shadow variables. However, when host is compiled in windows with MSVC C++
ABI and device is compiled with Itanium C++ ABI (e.g. AMDGPU), kernels and device symbols in fat
binary are mangled differently than host.

This patch gets the device side kernel and variable name by mangling them in the mangle context
of aux target.

Differential Revision: https://reviews.llvm.org/D58163

llvm-svn: 354004
2019-02-14 02:00:09 +00:00
Scott Linder
80a1ee46d8 [AMDGPU] Require at least protected visibility for certain symbols
This allows the global visibility controls to be restrictive while still
populating the dynamic symbol table where required.

Differential Revision: https://reviews.llvm.org/D56871

llvm-svn: 353870
2019-02-12 18:30:38 +00:00
Erich Keane
892e633194 Fix r350643 to limit COFF emission to <= 32 BYTES instead of BITS.
The patch in r350643 incorrectly sets the COFF emission based on bits
instead of bytes. This patch converts the 32 via CharUnits to bits to
compare the correct values.

Change-Id: Icf38a16470ad5ae3531374969c033557ddb0d323
llvm-svn: 353411
2019-02-07 15:14:11 +00:00
James Y Knight
9871db064d [opaque pointer types] Pass function types for runtime function calls.
Emit{Nounwind,}RuntimeCall{,OrInvoke} have been modified to take a
FunctionCallee as an argument, and CreateRuntimeFunction has been
modified to return a FunctionCallee. All callers have been updated.

Additionally, CreateBuiltinFunction is removed, as it was redundant
with CreateRuntimeFunction after some previous changes.

Differential Revision: https://reviews.llvm.org/D57668

llvm-svn: 353184
2019-02-05 16:42:33 +00:00
James Y Knight
916db651c8 Remove redundant FunctionDecl argument from a couple functions.
This argument was added in r254554 in order to support the
pass_object_size attribute. However, in r296076, the attribute's
presence is now also represented in FunctionProtoType's
ExtParameterInfo, and thus it's unnecessary to pass along a separate
FunctionDecl.

The functions modified are:
 RequiredArgs::forPrototype{,Plus}, and
 CodeGenTypes::ConvertFunctionType.

After this, it's also (again) unnecessary to have a separate
ConvertFunctionType function ConvertType, so convert callers back to
the latter, leaving the former as an internal helper function.

llvm-svn: 352946
2019-02-02 01:48:23 +00:00
Michael Kruse
251e1488e1 [OpenMP 5.0] Parsing/sema support for "omp declare mapper" directive.
This patch implements parsing and sema for "omp declare mapper"
directive. User defined mapper, i.e., declare mapper directive, is a new
feature in OpenMP 5.0. It is introduced to extend existing map clauses
for the purpose of simplifying the copy of complex data structures
between host and device (i.e., deep copy). An example is shown below:

    struct S {  int len;  int *d; };
    #pragma omp declare mapper(struct S s) map(s, s.d[0:s.len]) // Memory region that d points to is also mapped using this mapper.

Contributed-by: Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D56326

llvm-svn: 352906
2019-02-01 20:25:04 +00:00
James Y Knight
3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +00:00
Scott Linder
bef2663751 Add -fapply-global-visibility-to-externs for -cc1
Introduce an option to request global visibility settings be applied to
declarations without a definition or an explicit visibility, rather than
the existing behavior of giving these default visibility. When the
visibility of all or most extern definitions are known this allows for
the same optimisations -fvisibility permits without updating source code
to annotate all declarations.

Differential Revision: https://reviews.llvm.org/D56868

llvm-svn: 352391
2019-01-28 17:12:19 +00:00
Reid Kleckner
f09c19c896 [CodeGen] Implement isTriviallyRecursive with StmtVisitor instead of RecursiveASTVisitor
This code doesn't need to traverse types, lambdas, template arguments,
etc to detect trivial recursion. We can do a basic statement traversal
instead. This reduces the time spent compiling CodeGenModule.cpp, the
object file size (mostly reduced debug info), and the final executable
size by a small amount. I measured the exe mostly to check how much of
the overhead is from debug info, object file section headers, etc, vs
actual code.

metric   | before | after | diff
time (s) | 47.4   | 38.5  | -8.9
obj (kb) | 12888  | 12012 | -876
exe (kb) | 86072  | 85996 | -76

llvm-svn: 352232
2019-01-25 19:18:40 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Johannes Doerfert
ac991bbb44 Emit !callback metadata and introduce the callback attribute
With commit r351627, LLVM gained the ability to apply (existing) IPO
  optimizations on indirections through callbacks, or transitive calls.
  The general idea is that we use an abstraction to hide the middle man
  and represent the callback call in the context of the initial caller.
  It is described in more detail in the commit message of the LLVM patch
  r351627, the llvm::AbstractCallSite class description, and the
  language reference section on callback-metadata.

  This commit enables clang to emit !callback metadata that is
  understood by LLVM. It does so in three different cases:
    1) For known broker functions declarations that are directly
       generated, e.g., __kmpc_fork_call for the OpenMP pragma parallel.
    2) For known broker functions that are identified by their name and
       source location through the builtin detection, e.g.,
       pthread_create from the POSIX thread API.
    3) For user annotated functions that carry the "callback(callee, ...)"
       attribute. The attribute has to include the name, or index, of
       the callback callee and how the passed arguments can be
       identified (as many as the callback callee has). See the callback
       attribute documentation for detailed information.

Differential Revision: https://reviews.llvm.org/D55483

llvm-svn: 351629
2019-01-19 05:36:54 +00:00
Peter Collingbourne
e9f521069f CodeGen: Remove debug printf unintentionally added in r351228.
llvm-svn: 351241
2019-01-15 20:59:59 +00:00
Anton Korobeynikov
93165d648f [MSP430] Provide a toolchain description
This is an initial implementation for msp430 toolchain including
-mmcu option support
-mhwmult options support
-integrated-as by default

The toolchain uses msp430-elf-as as a linker and supports msp430-gcc toolchain tree.

Patch by Kristina Bessonova!

Differential Revision: https://reviews.llvm.org/D56658

llvm-svn: 351228
2019-01-15 19:44:05 +00:00
Shoaib Meenai
39287e759f [CodeGen] Clarify comment about COFF common symbol alignment
After a discussion on the commit thread, it seems the 32 byte alignment
limitation is an MSVC toolchain artifact, not an inherent COFF
restriction. Clarify the comment accordingly, since saying COFF in the
comment but using isKnownWindowsMSVCEnvironment in the conditional is
confusing. Also add a newline before the comment, which is consistent
with the local style.

Differential Revision: https://reviews.llvm.org/D56466

llvm-svn: 350754
2019-01-09 20:05:16 +00:00
Erich Keane
85c6224971 Limit COFF 'common' emission to <=32 alignment types.
As reported in PR33035, LLVM crashes if given a common object with an
alignment of greater than 32 bits. This is because the COFF file format
does not support these alignments, so emitting them is broken anyway.

This patch changes any global definitions greater than 32 bit alignment
to no longer be in 'common'.

https://bugs.llvm.org/show_bug.cgi?id=33035

Differential Revision: https://reviews.llvm.org/D56391

Change-Id: I48609289753b7f3b58c5e2bc1712756750fbd45a
llvm-svn: 350643
2019-01-08 18:44:22 +00:00
Saleem Abdulrasool
175890e1eb CodeGen: fix autolink emission on ELF
The autolinking extension for ELF uses a slightly different format for
encoding the autolink information compared to COFF and MachO.  Account
for this in the CGM to ensure that we do not assert when emitting
assembly or an object file.

llvm-svn: 350476
2019-01-05 19:27:12 +00:00
Saleem Abdulrasool
da32d7f147 CodeGen: switch iteration to range based for loop (NFC)
Change a loop to range based instead while working on cleaning up some
modules autolinking issues on Linux.  NFC.

llvm-svn: 350472
2019-01-05 18:39:32 +00:00
Artem Belevich
9953577cb2 [CUDA] Treat extern global variable shadows same as regular extern vars.
This fixes compiler crash when we attempted to compile this code:

extern __device__ int data;
__device__ int data = 1;

Differential Revision: https://reviews.llvm.org/D56033

llvm-svn: 349981
2018-12-22 01:11:09 +00:00
Scott Linder
de6beb02a5 Implement -frecord-command-line (-frecord-gcc-switches)
Implement options in clang to enable recording the driver command-line
in an ELF section.

Implement a new special named metadata, llvm.commandline, to support
frontends embedding their command-line options in IR/ASM/ELF.

This differs from the GCC implementation in some key ways:

* In GCC there is only one command-line possible per compilation-unit,
  in LLVM it mirrors llvm.ident and multiple are allowed.
* In GCC individual options are separated by NULL bytes, in LLVM entire
  command-lines are separated by NULL bytes. The advantage of the GCC
  approach is to clearly delineate options in the face of embedded
  spaces. The advantage of the LLVM approach is to support merging
  multiple command-lines unambiguously, while handling embedded spaces
  with escaping.

Differential Revision: https://reviews.llvm.org/D54487
Clang Differential Revision: https://reviews.llvm.org/D54489

llvm-svn: 349155
2018-12-14 15:38:15 +00:00
Artem Belevich
7b05666a19 [CUDA] Make all host-side shadows of device-side variables undef.
The host-side code can't (and should not) access the values that may
only exist on the device side. E.g. address of a __device__ function
does not exist on the host side as we don't generate the code for it there.

Differential Revision: https://reviews.llvm.org/D55663

llvm-svn: 349087
2018-12-13 21:43:04 +00:00
Richard Trieu
6368818fd5 Move CodeGenOptions from Frontend to Basic
Basic uses CodeGenOptions and should not depend on Frontend.

llvm-svn: 348827
2018-12-11 03:18:39 +00:00
Erich Keane
248ed07419 Make CPUDispatch resolver emit dependent functions.
Inline cpu_specific versions referenced before the cpu_dispatch function
weren't properly emitted, since they hadn't been referred to.  This
patch ensures that during resolver generation that all appropriate
versions are emitted.

Change-Id: I94c3766aaf9c75ca07a0ad8258efdbb834654ff8
llvm-svn: 348600
2018-12-07 15:31:23 +00:00
Richard Trieu
5337c74825 Remove CodeGen dependencies on Sema.
Move diagnostics from Sema to Frontend (or Common) so that CodeGen no longer
needs to include the Sema diagnostic IDs.

llvm-svn: 348458
2018-12-06 06:12:20 +00:00
Erich Keane
7304f0a66e Correct 'target' default behavior on redecl, allow forward declaration.
Declarations without the attribute were disallowed because it would be
ambiguous which 'target' it was supposed to be on.  For example:

void ___attribute__((target("v1"))) foo();
void foo(); // Redecl of above, or fwd decl of below?
void ___attribute__((target("v2"))) foo();

However, a first declaration doesn't have that problem, and erroring
prevents it from working in cases where the forward declaration is
useful.

Additionally, a forward declaration of target==default wouldn't properly
cause multiversioning, so this patch fixes that.

The patch was not split since the 'default' fix would require
implementing the same check for that case, followed by undoing the same
change for the fwd-decl implementation.

Change-Id: I66f2c5bc2477bcd3f7544b9c16c83ece257077b0
llvm-svn: 347805
2018-11-28 20:58:43 +00:00
Erich Keane
5c0d1925e3 [NFC] Move MultIversioning::Type into Decl so that it can be used in
CodeGen

Change-Id: I32b14edca3501277e0e65672eafe3eea38c6f9ae
llvm-svn: 347791
2018-11-28 18:34:14 +00:00
Reid Kleckner
755577168a [codeview] Expose -gcodeview-ghash for global type hashing
Summary:
Experience has shown that the functionality is useful. It makes linking
optimized clang with debug info for me a lot faster, 20s to 13s. The
type merging phase of PDB writing goes from 10s to 3s.

This removes the LLVM cl::opt and replaces it with a metadata flag.

After this change, users can do the following to use ghash:
- add -gcodeview-ghash to compiler flags
- replace /DEBUG with /DEBUG:GHASH in linker flags

Reviewers: zturner, hans, thakis, takuto.ikuta

Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D54370

llvm-svn: 347072
2018-11-16 18:47:41 +00:00
Erich Keane
de6480a38c [NFC] Move storage of dispatch-version to GlobalDecl
As suggested by Richard Smith, and initially put up for review here:
https://reviews.llvm.org/D53341, this patch removes a hack that was used
to ensure that proper target-feature lists were used when emitting
cpu-dispatch (and eventually, target-clones) implementations. As a part
of this, the GlobalDecl object is proliferated to a bunch more
locations.

Originally, this was put up for review (see above) to get acceptance on
the approach, though discussion with Richard in San Diego showed he
approved of the approach taken here.  Thus, I believe this is acceptable
for Review-After-commit

Differential Revision: https://reviews.llvm.org/D53341

Change-Id: I0a0bd673340d334d93feac789d653e03d9f6b1d5
llvm-svn: 346757
2018-11-13 15:48:08 +00:00
Dylan McKay
21e7f5e24e Use the correct address space when emitting the ctor function list
This patch modifies clang so that, if compiling for a target that
explicitly specifies a nonzero program memory address space, the
constructor list global will have the same address space as the
functions it contains.

AVR is the only in-tree backend which has a nonzero program memory
address space.

Without this, the IR verifier would always fail if a constructor
was used on a Harvard architecture backend.

This has no functional change to any in-tree backends except AVR.

llvm-svn: 346520
2018-11-09 17:15:06 +00:00
Erich Keane
9e94c18abe CPU-Dispatch- Fix type of a member function, prevent deferrals
The member type creation for a cpu-dispatch function was not correctly
including the 'this' parameter, so ensure that the type is properly
determined. Also, disable defer in the cases of emitting the functoins,
as it can end up resulting in the wrong version being emitted.

Change-Id: I0b8fc5e0b0d1ae1a9d98fd54f35f27f6e5d5d083
llvm-svn: 345838
2018-11-01 15:11:41 +00:00
Erich Keane
44731c5300 CPU-Dispatch-- Fix conflict between 'generic' and 'pentium'
When a dispatch function was being emitted that had both a generic and a
pentium configuration listed, we would assert.  This is because neither
configuration has any 'features' associated with it so they were both
considered the 'default' version.  'pentium' lacks any features because
we implement it in terms of __builtin_cpu_supports (instead of Intel
proprietary checks), which is unable to decern between the two.

The fix for this is to omit the 'generic' version from the dispatcher if
both are present. This permits existing code to compile, and still will
choose the 'best' version available (since 'pentium' is technically
better than 'generic').

Change-Id: I4b69f3e0344e74cbdbb04497845d5895dd05fda0
llvm-svn: 345826
2018-11-01 12:50:37 +00:00
Erik Pilkington
fa98390b3c NFC: Remove the ObjC1/ObjC2 distinction from clang (and related projects)
We haven't supported compiling ObjC1 for a long time (and never will again), so
there isn't any reason to keep these separate. This patch replaces
LangOpts::ObjC1 and LangOpts::ObjC2 with LangOpts::ObjC.

Differential revision: https://reviews.llvm.org/D53547

llvm-svn: 345637
2018-10-30 20:31:30 +00:00
Richard Smith
7c7e531f97 PR31978: Don't crash if CodeGen sees a top-level BindingDecl.
llvm-svn: 345362
2018-10-26 03:21:20 +00:00
Saleem Abdulrasool
98ac9984b0 CodeGen: correct the case for swift 4.2, 5.0
This corrects the leader for the swift names.  The encoding for 4.2 and
5.0 differ by a single bit on the second character and were swapped.

llvm-svn: 345360
2018-10-26 03:16:16 +00:00
Erich Keane
85822b304e Change keep-static-consts to work on static storage duration, not
storage class.

To be more in line with what GCC does, switch the condition to be based
on the Static Storage duration instead of the storage class.

Change-Id: I8e959d762433cda48855099353bf3c950b9d54b8
llvm-svn: 345302
2018-10-25 19:13:46 +00:00
Erich Keane
19a8adc9bd Implement Function Multiversioning for Non-ELF Systems.
Similar to how ICC handles CPU-Dispatch on Windows, this patch uses the
resolver function directly to forward the call to the proper function.
This is not nearly as efficient as IFuncs of course, but is still quite
useful for large functions specifically developed for certain
processors.

This is unfortunately still limited to x86, since it depends on
__builtin_cpu_supports and __builtin_cpu_is, which are x86 builtins.

The naming for the resolver/forwarding function for cpu-dispatch was
taken from ICC's implementation, which uses the unmodified name for this
(no mangling additions).  This is possible, since cpu-dispatch uses '.A'
for the 'default' version.

In 'target' multiversioning, this function keeps the '.resolver'
extension in order to keep the default function keeping the default
mangling.

Change-Id: I4731555a39be26c7ad59a2d8fda6fa1a50f73284

Differential Revision: https://reviews.llvm.org/D53586

llvm-svn: 345298
2018-10-25 18:57:19 +00:00
Saleem Abdulrasool
0c16a13fb9 CodeGen: alter CFConstantString class name for swift 5.0
Swift 5.0 has changed the name decoration for swift symbols, using a 'S' sigil
rather than 's' as in 4.2.  Adopt the new convention.

llvm-svn: 345291
2018-10-25 17:52:13 +00:00
Saleem Abdulrasool
81a650ee87 Driver,CodeGen: introduce support for Swift CFString layout
Add a new driver level flag `-fcf-runtime-abi=` that allows one to specify the
runtime ABI for CoreFoundation.  This controls the language interoperability.
In particular, this is relevant for generating the CFConstantString classes
(primarily through the `__builtin___CFStringMakeConstantString` builtin) which
construct a reference to the "CFObject"'s `isa` field.  This type differs
between swift 4.1 and 4.2+.

Valid values for the new option include:
  - objc [default behaviour] - enable ObjectiveC interoperability
  - swift-4.1 - enable interoperability with swift 4.1
  - swift-4.2 - enable interoperability with swift 4.2
  - swift-5.0 - enable interoperability with swift 5.0
  - swift [alias] - target the latest swift ABI

Furthermore, swift 4.2+ changed the layout for the CFString when building
CoreFoundation *without* ObjectiveC interoperability.  In such a case, a field
was added to the CFObject base type changing it from: <{ const int*, int }> to
<{ uintptr_t, uintptr_t, uint64_t }>.

In swift 5.0, the CFString type will be further adjusted to change the length
from a uint32_t on everything but BE LP64 targets to uint64_t.

Note that the default behaviour for clang remains unchanged and the new layout
must be explicitly opted into via `-fcf-runtime-abi=swift*`.

llvm-svn: 345222
2018-10-24 23:28:28 +00:00