Commit Graph

751 Commits

Author SHA1 Message Date
Matt Arsenault
16fc3db324 Use pointer size function where only a pointer is expected
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207023 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 21:10:15 +00:00
Matt Arsenault
b5a391a685 Remove more default address space argument usage.
These places are inconsequential in practice.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207021 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 20:58:57 +00:00
Rafael Espindola
8b9fe76c0c Remove AssemblyAnnotationWriter from NamedMDNode::print.
No functionality change, this parameter was always set to nullptr.

Patch by Robert Matusewicz!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206972 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 12:23:05 +00:00
Rafael Espindola
1021014c7b Fix DataLayout::operator==().
Patch by Maks Naumov!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206911 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 17:47:03 +00:00
Chandler Carruth
8677f2ff9a [Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.

Other sub-trees will follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206837 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:02:50 +00:00
Chandler Carruth
283b399377 [Modules] Make Support/Debug.h modular. This requires it to not change
behavior based on other files defining DEBUG_TYPE, which means it cannot
define DEBUG_TYPE at all. This is actually better IMO as it forces folks
to define relevant DEBUG_TYPEs for their files. However, it requires all
files that currently use DEBUG(...) to define a DEBUG_TYPE if they don't
already. I've updated all such files in LLVM and will do the same for
other upstream projects.

This still leaves one important change in how LLVM uses the DEBUG_TYPE
macro going forward: we need to only define the macro *after* header
files have been #include-ed. Previously, this wasn't possible because
Debug.h required the macro to be pre-defined. This commit removes that.
By defining DEBUG_TYPE after the includes two things are fixed:

- Header files that need to provide a DEBUG_TYPE for some inline code
  can do so by defining the macro before their inline code and undef-ing
  it afterward so the macro does not escape.

- We no longer have rampant ODR violations due to including headers with
  different DEBUG_TYPE definitions. This may be mostly an academic
  violation today, but with modules these types of violations are easy
  to check for and potentially very relevant.

Where necessary to suppor headers with DEBUG_TYPE, I have moved the
definitions below the includes in this commit. I plan to move the rest
of the DEBUG_TYPE macros in LLVM in subsequent commits; this one is big
enough.

The comments in Debug.h, which were hilariously out of date already,
have been updated to reflect the recommended practice going forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206822 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 22:55:11 +00:00
David Blaikie
e1c0863d74 Use unique_ptr to manage ownership of GCOVFunctions, Blocks, and Edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206796 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 21:40:16 +00:00
David Blaikie
b86fbcb08c Simplify destruction of Modules in LLVContextImpl.
This avoids copying the container by simply deleting until empty.

While I'd rather move to a stricter ownership semantic (unique_ptr),
SmallPtrSet can't cope with unique_ptr and the ownership semantics here
are a bit incestuous (Module sort of owns itself, but sort of doesn't
(if the LLVMContext is destroyed before the Module, then it deregisters
itself from the context... )).

Ideally Modules would be given to the context, or possibly an
emplace-like function to construct them there. Modules then shouldn't be
destroyed by LLVM API clients, but by interacting with the owner
(LLVMContext) directly (but even then, passing a Module* to LLVMContext
doesn't provide an easy way to destroy the Module, since the set would
be over unique_ptrs and you'd need a heterogenous lookup function which
SmallPtrSet doesn't have either).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206794 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 21:27:19 +00:00
Chandler Carruth
6060969b9b [PM] Fix a bug where we didn't properly clear the list map when the list
became empty. This would manifest later as an assert failure due to
a non-empty list map but an empty result map. This doesn't easily
manifest with just the module pass manager and the function pass
manager, but the next commit will add the CGSCC pass manager that hits
this assert immediately.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206744 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 11:11:54 +00:00
Diego Novillo
0a0d620db3 Fix bug 19437 - Only add discriminators for DWARF 4 and above.
Summary:
This prevents the discriminator generation pass from triggering if
the DWARF version being used in the module is prior to 4.

Reviewers: echristo, dblaikie

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3413

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206507 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-17 22:33:50 +00:00
Tom Stellard
57f45392e2 Added new functionality to LLVM C API to use DiagnosticInfo to handle errors
Patch by: Darren Powell

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206407 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-16 17:45:04 +00:00
Diego Novillo
b902acb16c Allow diagnostic handlers to check for optimization remarks.
Summary:
When optimization remarks are enabled via the driver flag -Rpass, we
should allow the FE diagnostic handler to check if the given pass name
needs a diagnostic.

We were unconditionally checking the pattern defined in opt's
-pass-remarks flag. This was causing the FE to not emit any diagnostics.

Reviewers: qcolombet

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3362

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206400 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-16 16:53:41 +00:00
Duncan P. N. Exon Smith
950c7b25bb verify-di: Add back braces for MSVC compatability
Fixup after r206300.

<rdar://problem/15500563>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206305 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 17:28:26 +00:00
Duncan P. N. Exon Smith
32791b02fa verify-di: Implement DebugInfoVerifier
Implement DebugInfoVerifier, which steals verification relying on
DebugInfoFinder from Verifier.

  - Adds LegacyDebugInfoVerifierPassPass, a ModulePass which wraps
    DebugInfoVerifier.  Uses -verify-di command-line flag.

  - Change verifyModule() to invoke DebugInfoVerifier as well as
    Verifier.

  - Add a call to createDebugInfoVerifierPass() wherever there was a
    call to createVerifierPass().

This implementation as a module pass should sidestep efficiency issues,
allowing us to turn debug info verification back on.

<rdar://problem/15500563>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206300 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 16:27:38 +00:00
Duncan P. N. Exon Smith
abf483ba52 verify-di: split out VerifierSupport
Split out assertion and output helpers from Verifier in preparation for
writing the DebugInfoVerifier.

<rdar://problem/15500563>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206299 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 16:27:32 +00:00
David Blaikie
3549f3cf19 Use unique_ptr to manage PassInfo instances in the PassRegistry
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206297 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 15:17:14 +00:00
Nick Lewycky
d63390cba1 Break PseudoSourceValue out of the Value hierarchy. It is now the root of its own tree containing FixedStackPseudoSourceValue (which you can use isa/dyn_cast on) and MipsCallEntry (which you can't). Anything that needs to use either a PseudoSourceValue* and Value* is strongly encouraged to use a MachinePointerInfo instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206255 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 07:22:52 +00:00
Craig Topper
0b6cb7104b [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206252 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 06:32:26 +00:00
Benjamin Kramer
15c435a367 Retire llvm::array_endof in favor of non-member std::end.
While there make array_lengthof constexpr if we have support for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206112 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-12 16:15:53 +00:00
Benjamin Kramer
479151ab7f Move MDBuilder's methods out of line.
Making them inline was a historical accident, they're neither hot nor
templated.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206109 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-12 14:26:59 +00:00
Diego Novillo
bb7b423bdc Fix use-after-free bug caught by address sanitizer:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/2959

The location string is returned as a std::string, not a StringRef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206032 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-11 13:55:56 +00:00
Alp Toker
46d36be2eb Fix some doc and comment typos
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205899 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 14:47:27 +00:00
Craig Topper
ec0f0bc6af [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205831 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 06:08:46 +00:00
Duncan P. N. Exon Smith
bd382db782 Verifier: Give the right message for bad atomic loads
Talk about load (not store) on an invalid atomic load.

<rdar://problem/16287567>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205777 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-08 17:07:44 +00:00
Diego Novillo
35d647b6f3 Add -pass-remarks flag to 'opt'.
Summary:
This adds support in 'opt' to filter pass remarks emitted by
optimization passes. A new flag -pass-remarks specifies which
passes should emit a diagnostic when LLVMContext::emitOptimizationRemark
is invoked.

This will allow the front end to simply pass along the regular
expression from its own -Rpass flag when launching the backend.

Depends on D3227.

Reviewers: qcolombet

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3291

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205775 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-08 16:42:38 +00:00
Diego Novillo
ccbf1d2a05 Add support for optimization reports.
Summary:
This patch adds backend support for -Rpass=, which indicates the name
of the optimization pass that should emit remarks stating when it
made a transformation to the code.

Pass names are taken from their DEBUG_NAME definitions.

When emitting an optimization report diagnostic, the lack of debug
information causes the diagnostic to use "<unknown>:0:0" as the
location string.

This is the back end counterpart for

http://llvm-reviews.chandlerc.com/D3226

Reviewers: qcolombet

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3227

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205774 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-08 16:42:34 +00:00
Andrew Trick
3c1f2eb75d Fix a (legacy) PassManager crash that occurs when a ModulePass
indirectly requires a function analysis.

This bug was reported by Jason Kim. He included a test case here:
http://reviews.llvm.org/D3312

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205753 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-08 03:40:34 +00:00
Eric Christopher
fc3588b336 Invert the option to enable debug info verification. No functional
change outside of the command line to enable it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205713 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-07 13:55:21 +00:00
David Blaikie
1c41705d34 DebugInfo: Support namespace aliases as DW_TAG_imported_declaration instead of DW_TAG_imported_module
I really should read the spec more often (and test GCC more often too).
I just assumed that namespace aliases would be the same as using
directives, except with a name. But apparently that's not how the DWARF
standards suggests they be implemented. DWARF4 provides an example and
other non-normative text suggesting that namespace aliases be
implemented by named imported declarations intsead of named imported
modules.

So be it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-06 06:29:01 +00:00
David Blaikie
ec37734d3c Remove unused parameter
Also update a few null pointers in this function to be consistent with
new null pointers being added.

Patch by Robert Matusewicz!

Differential Revision: http://reviews.llvm.org/D3123

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205682 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-05 23:33:25 +00:00
Saleem Abdulrasool
396e5e328c ARM: update subtarget information for Windows on ARM
Update the subtarget information for Windows on ARM.  This enables using the MC
layer to target Windows on ARM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205459 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-02 20:32:05 +00:00
Adrian Prantl
2f1e34736e Add a comment about the DIDescriptor class hierarchy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205358 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-01 21:04:24 +00:00
Adrian Prantl
1a2786b900 LTO type uniquing: store the Decl field of a DIImportedEntity as a DIRef.
No other functionality changes, DIBuilder testcase is included in a paired
CFE commit.

This relaxes the assertion in isScopeRef to also accept subclasses of
DIScope.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205279 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-01 03:41:04 +00:00
Tim Northover
7c3e057ff4 Intrinsics: add LLVMHalfElementsVectorType constraint
This is like the LLVMMatchType, except the verifier checks that the
second argument is a vector with the same base type and half the
number of elements.

This will be used by the ARM64 backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205079 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-29 07:04:54 +00:00
Tim Northover
b7de4288bc Intrinsics: expand semantics of LLVMExtendedVectorType (& trunc)
These are used in the ARM backends to aid type-checking on patterns involving
intrinsics. By making sure one argument is an extended/truncated version of
another.

However, there's no reason to limit them to just vectors types. For example
AArch64 has the instruction "uqshrn sD, dN, #imm" which would naturally use an
intrinsic taking an i64 and returning an i32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 12:31:39 +00:00
Rafael Espindola
f165cf7ce8 Prevent alias from pointing to weak aliases.
This adds back r204781.

Original message:

Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204934 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 15:26:56 +00:00
Justin Bogner
2a6873fdf3 llvm-cov: Handle functions with no line number
Functions may in an instrumented binary but not in the original source
when they're inserted by the compiler or the runtime. These functions
aren't meaningful to the user, so teach llvm-cov to skip over them
instead of crashing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204863 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 22:03:06 +00:00
Rafael Espindola
72db10a995 Revert "Prevent alias from pointing to weak aliases."
This reverts commit r204781.

I will follow up to with msan folks to see what is what they
were trying to do with aliases to weak aliases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204784 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 06:14:40 +00:00
Rafael Espindola
33845aa8c4 Prevent alias from pointing to weak aliases.
Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 04:48:47 +00:00
Yaron Keren
d8ceb275c2 Disable Visual C++ warning 4722 about aborting a destructor,
it has no value for us.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204704 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-25 08:42:49 +00:00
Yaron Keren
d816eda3c7 In Release modes, Visual Studio complains that the Operator destructor in User.cpp
never returns, which is true by design. 

Initially assumed that the reason is llvm_unreachable being dependent on NDEBUG.

However, even if llvm_unreachable is replaced by __assume(false), VC still warns in
Release modes but not in Debug modes...

The real reason turned out to be optimization flags.
With /Od in Debug modes the warning is not issued whereas with /O1 it is.

I could not find any documentation to this effect, but it is reproducable:

Try compiling http://msdn.microsoft.com/en-us/library/khwfyc5d(v=vs.90).aspx
with /O1 and then with /Od.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204659 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-24 19:48:13 +00:00
Nuno Lopes
2ca626570f remove a bunch of unused private methods
found with a smarter version of -Wunused-member-function that I'm playwing with.
Appologies in advance if I removed someone's WIP code.

 include/llvm/CodeGen/MachineSSAUpdater.h            |    1 
 include/llvm/IR/DebugInfo.h                         |    3 
 lib/CodeGen/MachineSSAUpdater.cpp                   |   10 --
 lib/CodeGen/PostRASchedulerList.cpp                 |    1 
 lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp    |   10 --
 lib/IR/DebugInfo.cpp                                |   12 --
 lib/MC/MCAsmStreamer.cpp                            |    2 
 lib/Support/YAMLParser.cpp                          |   39 ---------
 lib/TableGen/TGParser.cpp                           |   16 ---
 lib/TableGen/TGParser.h                             |    1 
 lib/Target/AArch64/AArch64TargetTransformInfo.cpp   |    9 --
 lib/Target/ARM/ARMCodeEmitter.cpp                   |   12 --
 lib/Target/ARM/ARMFastISel.cpp                      |   84 --------------------
 lib/Target/Mips/MipsCodeEmitter.cpp                 |   11 --
 lib/Target/Mips/MipsConstantIslandPass.cpp          |   12 --
 lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp              |   21 -----
 lib/Target/NVPTX/NVPTXISelDAGToDAG.h                |    2 
 lib/Target/PowerPC/PPCFastISel.cpp                  |    1 
 lib/Transforms/Instrumentation/AddressSanitizer.cpp |    2 
 lib/Transforms/Instrumentation/BoundsChecking.cpp   |    2 
 lib/Transforms/Instrumentation/MemorySanitizer.cpp  |    1 
 lib/Transforms/Scalar/LoopIdiomRecognize.cpp        |    8 -
 lib/Transforms/Scalar/SCCP.cpp                      |    1 
 utils/TableGen/CodeEmitterGen.cpp                   |    2 
 24 files changed, 2 insertions(+), 261 deletions(-)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204560 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-23 17:09:26 +00:00
Hans Wennborg
a2ff1c5de1 Fix comment (PR19188)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204256 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-19 18:41:38 +00:00
Alon Mishne
086494730d [C++11] Change DebugInfoFinder to use range-based loops
Also changes the iterators to return actual DI type over MDNode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204130 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 09:41:07 +00:00
Adrian Prantl
5e8144df32 Switch the type field in DIVariable and DIGlobalVariable over to DITypeRefs.
This allows us to catch more opportunities for ODR-based type uniquing
during LTO.
Paired commit with CFE which updates some testcases to verify the new
DIBuilder behavior.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204106 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 02:34:58 +00:00
Benjamin Kramer
571832b930 Make some assertions on constant expressions static.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204011 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-15 18:47:07 +00:00
Diego Novillo
3f7c2f31ff Use DiagnosticInfo facility.
Summary:
The sample profiler pass emits several error messages. Instead of
just aborting the compiler with report_fatal_error, we can emit
better messages using DiagnosticInfo.

This adds a new sub-class of DiagnosticInfo to handle the sample
profiler.

Reviewers: chandlerc, qcolombet

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3086

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203976 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-14 21:58:59 +00:00
Rafael Espindola
1f21e0dd0d Remove the linker_private and linker_private_weak linkages.
These linkages were introduced some time ago, but it was never very
clear what exactly their semantics were or what they should be used
for. Some investigation found these uses:

* utf-16 strings in clang.
* non-unnamed_addr strings produced by the sanitizers.

It turns out they were just working around a more fundamental problem.
For some sections a MachO linker needs a symbol in order to split the
section into atoms, and llvm had no idea that was the case. I fixed
that in r201700 and it is now safe to use the private linkage. When
the object ends up in a section that requires symbols, llvm will use a
'l' prefix instead of a 'L' prefix and things just work.

With that, these linkages were already dead, but there was a potential
future user in the objc metadata information. I am still looking at
CGObjcMac.cpp, but at this point I am convinced that linker_private
and linker_private_weak are not what they need.

The objc uses are currently split in

* Regular symbols (no '\01' prefix). LLVM already directly provides
whatever semantics they need.
* Uses of a private name (start with "\01L" or "\01l") and private
linkage. We can drop the "\01L" and "\01l" prefixes as soon as llvm
agrees with clang on L being ok or not for a given section. I have two
patches in code review for this.
* Uses of private name and weak linkage.

The last case is the one that one could think would fit one of these
linkages. That is not the case. The semantics are

* the linker will merge these symbol by *name*.
* the linker will hide them in the final DSO.

Given that the merging is done by name, any of the private (or
internal) linkages would be a bad match. They allow llvm to rename the
symbols, and that is really not what we want. From the llvm point of
view, these objects should really be (linkonce|weak)(_odr)?.

For now, just keeping the "\01l" prefix is probably the best for these
symbols. If we one day want to have a more direct support in llvm,
IMHO what we should add is not a linkage, it is just a hidden_symbol
attribute. It would be applicable to multiple linkages. For example,
on weak it would produce the current behavior we have for objc
metadata. On internal, it would be equivalent to private (and we
should then remove private).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203866 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 23:18:37 +00:00
Chandler Carruth
04239506f1 [PM] Stop playing fast and loose with rebinding of references. However
convenient it is to imagine a world where this works, that is not C++ as
was pointed out in review. The standard even goes to some lengths to
preclude any attempt at this, for better or worse. Maybe better. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203775 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 09:50:31 +00:00
Rafael Espindola
38048cdb1c Reject alias to undefined symbols in the verifier.
On ELF and COFF an alias is just another name for a position in the file.
There is no way to refer to a position in another file, so an alias to
undefined is meaningless.

MachO currently doesn't support aliases. The spec has a N_INDR, which when
implemented will have a different set of restrictions. Adding support for
it shouldn't be harder than any other IR extension.

For now, having the IR represent what is actually possible with current
tools makes it easier to fix the design of GlobalAlias.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203705 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-12 20:15:49 +00:00