1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-20 03:23:01 +02:00
Commit Graph

446 Commits

Author SHA1 Message Date
Mehdi Amini
e8b9c531d4 Extract a TBAAVerifier out of the verifier (NFC)
This is intended to be used (in a later patch) by the BitcodeReader
to detect invalid TBAA and drop them when loading bitcode, so that
we don't break client that have legacy bitcode with possible invalid
TBAA.

Differential Revision: https://reviews.llvm.org/D27838

llvm-svn: 289927
2016-12-16 06:29:14 +00:00
Nico Weber
1fcb5dfa62 attempt to fix windows build
llvm-svn: 289926
2016-12-16 05:13:02 +00:00
Adrian Prantl
2345112c5b [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289920
2016-12-16 04:25:54 +00:00
Adrian Prantl
daf4fef1f9 Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289902 while investigating bot berakage.

llvm-svn: 289906
2016-12-16 01:00:30 +00:00
Adrian Prantl
0eee52640f [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289902
2016-12-16 00:36:43 +00:00
Sanjoy Das
de96d7b688 [Verifier] Allow TBAA metadata on atomicrmw and atomiccmpxchg
This used to be allowed before r289402 by default (before r289402 you
could have TBAA metadata on any instruction), and while I'm not sure
that it helps, it does sound reasonable enough to not fail the verifier
and we have out-of-tree users who use this.

llvm-svn: 289872
2016-12-15 21:23:44 +00:00
Stephan Bergmann
aba15d97df Replace APFloatBase static fltSemantics data members with getter functions
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.

Differential Revision: https://reviews.llvm.org/D26671

llvm-svn: 289647
2016-12-14 11:57:17 +00:00
Sanjoy Das
a0e8011216 [Verifier] Add verification for TBAA metadata
Summary:
This change adds some verification in the IR verifier around struct path
TBAA metadata.

Other than some basic sanity checks (e.g. we get constant integers where
we expect constant integers), this checks:

 - That by the time an struct access tuple `(base-type, offset)` is
   "reduced" to a scalar base type, the offset is `0`.  For instance, in
   C++ you can't start from, say `("struct-a", 16)`, and end up with
   `("int", 4)` -- by the time the base type is `"int"`, the offset
   better be zero.  In particular, a variant of this invariant is needed
   for `llvm::getMostGenericTBAA` to be correct.

 - That there are no cycles in a struct path.

 - That struct type nodes have their offsets listed in an ascending
   order.

 - That when generating the struct access path, you eventually reach the
   access type listed in the tbaa tag node.

Reviewers: dexonsmith, chandlerc, reames, mehdi_amini, manmanren

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D26438

llvm-svn: 289402
2016-12-11 20:07:15 +00:00
Adrian Prantl
57907269da [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

llvm-svn: 288683
2016-12-05 18:04:47 +00:00
Chandler Carruth
dad102bcc9 [PM] Change the static object whose address is used to uniquely identify
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.

This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.

However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.

And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.

This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.

We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.

Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!

While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.

Differential Revision: https://reviews.llvm.org/D27031

llvm-svn: 287783
2016-11-23 17:53:26 +00:00
Sanjoy Das
1fd60c72fb [Verifier] clang-format a section; NFC
Suggested in D26438 since I'm touching related code.

llvm-svn: 286388
2016-11-09 19:36:39 +00:00
Sanjoy Das
e43f7f887e [TBAA] Drop support for "old style" scalar TBAA tags
Summary:
We've had support for auto upgrading old style scalar TBAA access
metadata tags into the "new" struct path aware TBAA metadata for 3 years
now.  The only way to actually generate old style TBAA was explicitly
through the IRBuilder API.  I think this is a good time for dropping
support for old style scalar TBAA.

I'm not removing support for textual or bitcode upgrade -- if you have
IR with the old style scalar TBAA tags that go through the AsmParser orf
the bitcode parser before LLVM sees them, they will keep working as
usual.

Note:

  %val = load i32, i32* %ptr, !tbaa !N
  !N = < scalar tbaa node >

is equivalent to

  %val = load i32, i32* %ptr, !tbaa !M
  !N = < scalar tbaa node >
  !M = !{!N, !N, 0}

Reviewers: manmanren, chandlerc, sunfish

Subscribers: mcrosier, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D26229

llvm-svn: 286291
2016-11-08 20:46:01 +00:00
Victor Leschuk
8feb81b088 DebugInfo: make DW_TAG_atomic_type valid
DW_TAG_atomic_type was already included in Dwarf.defs and emitted correctly,
however Verifier didn't recognize it as valid.
Thus we introduce the following changes:

  * Make DW_TAG_atomic_type valid tag for IR and DWARF (enabled only with -gdwarf-5)
  * Add it to related docs
  * Add DebugInfo tests

Differential Revision: https://reviews.llvm.org/D26144

llvm-svn: 285624
2016-10-31 19:09:38 +00:00
Adrian Prantl
77c7c501d3 Verifier: Reject any unknown named MD nodes in the llvm.dbg namespace.
This came out of a discussion in https://reviews.llvm.org/D25285.

There used to be various other llvm.dbg.* nodes, but we don't support
upgrading them and we want to reserve the namespace for future uses.

This also removes an entirely obsolete and bitrotted testcase for PR7662.

Reapplies 283390 with a forgotten testcase.

llvm-svn: 283400
2016-10-05 22:15:37 +00:00
Adrian Prantl
6d1cf4c28d Revert "Verifier: Reject any unknown named MD nodes in the llvm.dbg namespace."
Forgot to add a testcase in r283390.

llvm-svn: 283399
2016-10-05 22:15:34 +00:00
Adrian Prantl
0991b8d030 Verifier: Reject any unknown named MD nodes in the llvm.dbg namespace.
This came out of a discussion in https://reviews.llvm.org/D25285.

There used to be various other llvm.dbg.* nodes, but we don't support
upgrading them and we want to reserve the namespace for future uses.

This also removes an entirely obsolete and bitrotted testcase for PR7662.

llvm-svn: 283390
2016-10-05 21:31:19 +00:00
Adrian Prantl
f7b060540c Verifier: Mark orphaned DICompileUnits as a debug info failure.
This is a follow-up to r268778 that adds a couple of missing cases,
most notably orphaned compile units.

rdar://problem/28193346

llvm-svn: 281508
2016-09-14 17:30:37 +00:00
Peter Collingbourne
a9fbb2813b DebugInfo: New metadata representation for global variables.
This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

llvm-svn: 281284
2016-09-13 01:12:59 +00:00
Arnold Schwaighofer
7d4fb4b444 It should also be legal to pass a swifterror parameter to a call as a swifterror
argument.

rdar://28233388

llvm-svn: 281147
2016-09-10 19:42:53 +00:00
Duncan P. N. Exon Smith
57584a7379 ADT: Remove external uses of ilist_iterator, NFC
Delete the dead code for Write(ilist_iterator) in the IR Verifier,
inline report(ilist_iterator) at its call sites in the MachineVerifier,
and use simple_ilist<>::iterator in SymbolTableListTraits.

The only remaining reference to ilist_iterator outside of the ilist
implementation is from MachineInstrBundleIterator.  I'll get rid of that
in a follow-up.

llvm-svn: 280565
2016-09-03 01:22:56 +00:00
Gor Nishanov
cc3ff9c81d [Coroutines] Part 9: Add cleanup subfunction.
Summary:
[Coroutines] Part 9: Add cleanup subfunction.

This patch completes coroutine heap allocation elision. Now, the heap elision example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex3.ll)

Intrinsic Changes:
* coro.free gets a token parameter tying it to coro.id to allow reliably discovering all coro.frees associated with a particular coroutine.
* coro.id gets an extra parameter that points back to a coroutine function. This allows to check whether a coro.id describes the enclosing function or it belongs to a different function that was later inlined.

CoroSplit now creates three subfunctions:
# f$resume - resume logic
# f$destroy - cleanup logic, followed by a deallocation code
# f$cleanup - just the cleanup code

CoroElide pass during devirtualization replaces coro.destroy with either f$destroy or f$cleanup depending whether heap elision is performed or not.

Other fixes, improvements:
* Fixed buglet in Shape::buildFrame that was not creating coro.save properly if coroutine has more than one suspend point.

* Switched to using variable width suspend index field (no longer limited to 32 bit index field can be as little as i1 or as large as i<whatever-size_t-is>)

Reviewers: majnemer

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23844

llvm-svn: 279971
2016-08-29 14:34:12 +00:00
Nico Weber
3170ff6896 fix typo 'varaible' in assert
llvm-svn: 279636
2016-08-24 16:34:54 +00:00
Eugene Zelenko
10633be3a7 Fix some Clang-tidy modernize-use-using and Include What You Use warnings.
Differential revision: https://reviews.llvm.org/D23478

llvm-svn: 278583
2016-08-13 00:50:41 +00:00
Gor Nishanov
37bbef4980 [Coroutines]: Part6b: Add coro.id intrinsic.
Summary:
1. Make coroutine representation more robust against optimization that may duplicate instruction by introducing coro.id intrinsics that returns a token that will get fed into coro.alloc and coro.begin. Due to coro.id returning a token, it won't get duplicated and can be used as reliable indicator of coroutine identify when a particular coroutine call gets inlined.
2. Move last three arguments of coro.begin into coro.id as they will be shared if coro.begin will get duplicated.
3. doc + test + code updated to support the new intrinsic.

Reviewers: mehdi_amini, majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23412

llvm-svn: 278481
2016-08-12 05:45:49 +00:00
David Majnemer
5423e4bff5 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
Sanjoy Das
1dda66d272 [Statepoints] Minor cosmetic change; NFC
The verification failure message was missing a space.

llvm-svn: 278309
2016-08-11 00:56:46 +00:00
Benjamin Kramer
a733725b3a Move helpers into anonymous namespaces. NFC.
llvm-svn: 277916
2016-08-06 11:13:10 +00:00
Gor Nishanov
d04999a10d Part 4c: Coroutine Devirtualization: Devirtualize coro.resume and coro.destroy.
Summary:
This is the 4c patch of the coroutine series. CoroElide pass now checks if PostSplit coro.begin
is referenced by coro.subfn.addr intrinsics. If so replace coro.subfn.addrs with an appropriate coroutine
subfunction associated with that coro.begin.

Documentation and overview is here: http://llvm.org/docs/Coroutines.html.

Upstreaming sequence (rough plan)
1.Add documentation. (https://reviews.llvm.org/D22603)
2.Add coroutine intrinsics. (https://reviews.llvm.org/D22659)
3.Add empty coroutine passes. (https://reviews.llvm.org/D22847)
4.Add coroutine devirtualization + tests.
ab) Lower coro.resume and coro.destroy (https://reviews.llvm.org/D22998)
c) Do devirtualization <= we are here
5.Add CGSCC restart trigger + tests.
6.Add coroutine heap elision + tests.
7.Add the rest of the logic (split into more patches)

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23229

llvm-svn: 277908
2016-08-06 02:16:35 +00:00
David Majnemer
cac831b368 [coroutines] Part 4[ab]: Coroutine Devirtualization: Lower coro.resume and coro.destroy.
This is the forth patch in the coroutine series. CoroEaly pass now lowers coro.resume
and coro.destroy intrinsics by replacing them with an indirect call to an address
returned by coro.subfn.addr intrinsic. This is done so that CGPassManager recognizes
devirtualization when CoroElide replaces a call to coro.subfn.addr with an appropriate
function address.

Patch by Gor Nishanov!

Differential Revision: https://reviews.llvm.org/D22998

llvm-svn: 277765
2016-08-04 20:30:07 +00:00
Sanjoy Das
7931b59359 [Verifier] Disallow illegal ptr<->int casts in ConstantExprs
This should have been a part of rL277085, but I hadn't considered this
case.

llvm-svn: 277413
2016-08-02 02:55:57 +00:00
Sanjoy Das
2f2a2a4518 Tie the Verifier class to a Module; NFCI
Summary:
This commit changes the Verifier class to accept a Module via the
constructor to make it obvious that a specific instance of the class is
only intended to work with a specific module.  The `updateModule` setter
(despite being private) was making this fact less transparent.

There are fields in the `Verifier` class like `DeoptimizeDeclarations`
and `GlobalValueVisited` which are module specific, so a given
Verifier instance will not in fact work across multiple modules today.
This change just makes that more obvious.

The motivation is to make it easy to get to the datalayout of the
module unambiguously.  That is required to verify that `inttoptr` and
`ptrtoint` constant expressions are well typed in the face of
non-integral pointer types.

Reviewers: dexonsmith, bkramer, majnemer, chandlerc

Subscribers: mehdi_amini, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23040

llvm-svn: 277409
2016-08-02 01:34:50 +00:00
David Majnemer
0e0bcfac37 [Verifier] Resume instructions can only be in functions w/ a personality
This fixes PR28799.

llvm-svn: 277360
2016-08-01 18:06:34 +00:00
Justin Lebar
b1ec783712 Revert "Don't invoke getName() from Function::isIntrinsic().", rL276942.
This broke some out-of-tree AMDGPU tests that relied on the old behavior
wherein isIntrinsic() would return true for any function that starts
with "llvm.".  And in general that change will not play nicely with
out-of-tree backends.

llvm-svn: 277087
2016-07-28 23:58:15 +00:00
Sanjoy Das
76a6f34a7e [IR] Introduce a non-integral pointer type
Summary:
This change adds a `ni` specifier in the `datalayout` string to denote
pointers in some given address spaces as "non-integral", and adds some
typing rules around these special pointers.

Reviewers: majnemer, chandlerc, atrick, dberlin, eli.friedman, tstellarAMD, arsenm

Subscribers: arsenm, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D22488

llvm-svn: 277085
2016-07-28 23:43:38 +00:00
Justin Lebar
c1a3abfb94 Don't invoke getName() from Function::isIntrinsic().
Summary:
getName() involves a hashtable lookup, so is expensive given how
frequently isIntrinsic() is called.  (In particular, many users cast to
IntrinsicInstr or one of its subclasses before calling
getIntrinsicID().)

This has an incidental functional change: Before, isIntrinsic() would
return true for any function whose name started with "llvm.", even if it
wasn't properly an intrinsic.  The new behavior seems more correct to
me, because it's strange to say that isIntrinsic() is true, but
getIntrinsicId() returns "not an intrinsic".

Some callers want the old behavior -- they want to know whether the
caller is a recognized intrinsic, or might be one in some other version
of LLVM.  For them, we added Function::hasLLVMReservedName(), which
checks whether the name starts with "llvm.".

This change is good for a 1.5% e2e speedup compiling a large Eigen
benchmark.

Reviewers: bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D22065

llvm-svn: 276942
2016-07-27 23:46:57 +00:00
Nicolai Haehnle
fe1657d8ae Add writeonly IR attribute
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

llvm-svn: 274485
2016-07-04 08:01:29 +00:00
Matt Arsenault
5c73422406 Verifier: Reject non-float !fpmath
Code already assumes this is float. getFPAccuracy()
crashes on any other type.

llvm-svn: 273912
2016-06-27 19:43:15 +00:00
Artur Pilipenko
93a6698cb0 NFC. Move verifyIntrinsicIsVarArg from verifier to Intrinsic::matchIntrinsicVarArg since it will be reused for intrinsic remangling code
llvm-svn: 273685
2016-06-24 14:47:27 +00:00
Artur Pilipenko
d5f0783b51 NFC. Move Verifier::verifyIntrinsicType to Intrinsics.h
Move Verifier::verifyIntrinsicType to Intrinsics::matchIntrinsicsType. Will be used to accumulate overloaded types of a given intrinsic by the upcoming patch to fix intrinsics names when overloaded types are renamed.
    
Reviewed By: reames
    
Differential Revision: http://reviews.llvm.org/D19372

llvm-svn: 273424
2016-06-22 14:56:33 +00:00
Peter Collingbourne
413c7840e0 IR: Allow metadata attachments on declarations, and fix lazy loaded metadata issue with globals.
This change is motivated by an upcoming change to the metadata representation
used for CFI. The indirect function call checker needs type information for
external function declarations in order to correctly generate jump table
entries for such declarations. We currently associate such type information
with declarations using a global metadata node, but I plan [1] to move all
such metadata to global object attachments.

In bitcode, metadata attachments for function declarations appear in the
global metadata block. This seems reasonable to me because I expect metadata
attachments on declarations to be uncommon. In the long term I'd also expect
this to be the case for CFI, because we'd want to use some specialized bitcode
format for this metadata that could be read as part of the ThinLTO thin-link
phase, which would mean that it would not appear in the global metadata block.

To solve the lazy loaded metadata issue I was seeing with D20147, I use the
same bitcode representation for metadata attachments for global variables as I
do for function declarations. Since there's a use case for metadata attachments
in the global metadata block, we might as well use that representation for
global variables as well, at least until we have a mechanism for lazy loading
global variables.

In the assembly format, the metadata attachments appear after the "declare"
keyword in order to avoid a parsing ambiguity.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21052

llvm-svn: 273336
2016-06-21 23:42:48 +00:00
Chandler Carruth
4cad16d76c [PM] Remove support for omitting the AnalysisManager argument to new
pass manager passes' `run` methods.

This removes a bunch of SFINAE goop from the pass manager and just
requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead
argument. This is a small price to pay for the simplicity of the system
as a whole, despite the noise that changing it causes at this stage.

This will also helpfull allow us to make the signature of the run
methods much more flexible for different kinds af passes to support
things like intelligently updating the pass's progression over IR units.

While this touches many, many, files, the changes are really boring.
Mostly made with the help of my trusty perl one liners.

Thanks to Sean and Hal for bouncing ideas for this with me in IRC.

llvm-svn: 272978
2016-06-17 00:11:01 +00:00
Peter Collingbourne
3295a45473 Verifier: check that functions have at most a single !prof attachment.
llvm-svn: 272734
2016-06-14 23:13:15 +00:00
Peter Collingbourne
5dcb77e9fb IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Benjamin Kramer
7287b240f4 [Verifier] Simplify code. No functionality change intended.
llvm-svn: 272517
2016-06-12 17:46:23 +00:00
Benjamin Kramer
5d5a0e4f68 Avoid copies of std::strings and APInt/APFloats where we only read from it
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.

llvm-svn: 272126
2016-06-08 10:01:20 +00:00
Peter Collingbourne
b49c377b70 Verifier: Simplify and fix issue where we were not verifying unmaterialized functions.
Arrange to call verify(Function &) on each function, followed by
verify(Module &), whether the verifier is being used from the pass or
from verifyModule(). As a side effect, this fixes an issue that caused
us not to call verify(Function &) on unmaterialized functions from
verifyModule().

Differential Revision: http://reviews.llvm.org/D21042

llvm-svn: 271956
2016-06-06 23:21:27 +00:00
Peter Collingbourne
77f644cc10 Verifier: Remove dead code.
Remove previously unreachable code that verifies that a function definition has
an entry block. By definition, a function definition has at least one block.

llvm-svn: 271948
2016-06-06 22:32:52 +00:00
Sanjoy Das
ace2883be0 [IR] Disallow loading and storing unsized types
Summary:
It isn't clear what is the operational meaning of loading or storing an
unsized types, since it cannot be lowered into something meaningful.
Since there does not seem to be any practical need for it either, make
such loads and stores illegal IR.

Reviewers: majnemer, chandlerc

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20846

llvm-svn: 271402
2016-06-01 16:13:10 +00:00
Peter Collingbourne
232f184d9b IR: Allow multiple global metadata attachments with the same type.
This will be necessary to allow the global merge pass to attach
multiple debug info metadata nodes to global variables once we reverse
the edge from DIGlobalVariable to GlobalVariable.

Differential Revision: http://reviews.llvm.org/D20414

llvm-svn: 271358
2016-06-01 01:17:57 +00:00
Adrian Prantl
6e37fd5afd Port the strip-invalid-debuginfo logic to the legacy verifier pass, too.
Since r268966 the modern Verifier pass defaults to stripping invalid debug info
in nonasserts builds.  This patch ports this behavior back to the legacy
Verifier pass as well.  The primary motivation is that the clang frontend
accepts bitcode files as input but is still using the legacy pass pipeline.

Background: The problem I'm trying to solve with this sequence of patches is
that historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about breaking
bitcode compatibility with existing producers. For example, we don't necessarily
want IR produced by an older version of clang to be rejected by an LTO link just
because of malformed debug info, and rather provide an option to strip it. Note
that merely outdated (but well-formed) debug info would continue to be
auto-upgraded in this scenario.

http://reviews.llvm.org/D20629
<rdar://problem/26448800>

llvm-svn: 270768
2016-05-25 21:33:20 +00:00