Current implementation may end up emitting an undefined reference for
an "inline __attribute__((always_inline))" function by generating an
"available_externally alwaysinline" IR function for it and then failing to
inline all the calls. This happens when a call to such function is in dead
code. As the inliner is an SCC pass, it does not process dead code.
Libc++ relies on the compiler never emitting such undefined reference.
With this patch, we emit a pair of
1. internal alwaysinline definition (called F.alwaysinline)
2a. A stub F() { musttail call F.alwaysinline }
-- or, depending on the linkage --
2b. A declaration of F.
The frontend ensures that F.inlinefunction is only used for direct
calls, and the stub is used for everything else (taking the address of
the function, really). Declaration (2b) is emitted in the case when
"inline" is meant for inlining only (like __gnu_inline__ and some
other cases).
This approach, among other nice properties, ensures that alwaysinline
functions are always internal, making it impossible for a direct call
to such function to produce an undefined symbol reference.
This patch is based on ideas by Chandler Carruth and Richard Smith.
llvm-svn: 247465
We used to only select an inheritance model if the pointer to member was
nullptr. Instead, select a model regardless of the member pointer's
value.
N.B. This bug was exposed by making member pointers report true for
isIncompleteType but has been latent since the member pointer scheme's
inception.
llvm-svn: 247464
It seems that there is small bug, and we can't generate assume loads
when some virtual functions have internal visibiliy
This reverts commit 982bb7d966947812d216489b3c519c9825cacbf2.
llvm-svn: 247332
Given a reference to a pointer to member whose class's inheritance model
is unspecified, make sure we come up with an inheritance model in
plausible places. One place we were missing involved LValue to RValue
conversion, another involved unary type traits.
llvm-svn: 247248
This flag causes the compiler to emit bit set entries for functions as well
as runtime bitset checks at indirect call sites. Depends on the new function
bitset mechanism.
Differential Revision: http://reviews.llvm.org/D11857
llvm-svn: 247238
Generating call assume(icmp %vtable, %global_vtable) after constructor
call for devirtualization purposes.
For more info go to:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html
Edit:
Fixed version because of PR24479.
After this patch got reverted because of ScalarEvolution bug (D12719)
Merged after John McCall big patch (Added Address).
http://reviews.llvm.org/D11859
llvm-svn: 247199
We know that a reference can always be dereferenced. However, we don't
always know the number of bytes if the reference's pointee type is
incomplete. This case was correctly handled but we didn't consider the
case where the type is complete but we cannot calculate its size for ABI
specific reasons. In this specific case, a member pointer's size is
available only under certain conditions.
This fixes PR24703.
llvm-svn: 247188
Summary:
If class or struct has not declared a destructor,
no destructor is emitted, and members are not poisoned
after destruction. This case highlights bug in current
implementation of use-after-dtor poisoning (detailed
in https://github.com/google/sanitizers/issues/596).
Reviewers: eugenis, kcc
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D12616
Only check simplest object for existence of sanitizing callback.
Rename test.
llvm-svn: 247025
Introduce an Address type to bundle a pointer value with an
alignment. Introduce APIs on CGBuilderTy to work with Address
values. Change core APIs on CGF/CGM to traffic in Address where
appropriate. Require alignments to be non-zero. Update a ton
of code to compute and propagate alignment information.
As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.
The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned. Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay. I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.
Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.
We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment. In particular,
field access now uses alignmentAtOffset instead of min.
Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs. For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint. That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.
ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments. In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments. That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.
I partially punted on applying this work to CGBuiltin. Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.
llvm-svn: 246985
This fixes an issue raised in D12412, where we generated invalid IR.
Thanks to Vedant Kumar for coming up with the initial work around.
Differential Revision: http://reviews.llvm.org/D12412
llvm-svn: 246880
Summary:
Dtor sanitization handled amidst other dtor cleanups,
between cleaning bases and fields. Sanitizer call pushed onto
stack of cleanup operations.
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D12022
Refactoring dtor sanitizing emission order.
- Support multiple inheritance by poisoning after
member destructors are invoked, and before base
class destructors are invoked.
- Poison for virtual destructor and virtual bases.
- Repress dtor aliasing when sanitizing in dtor.
- CFE test for dtor aliasing, and repression of aliasing in dtor
code generation.
- Poison members on field-by-field basis, with collective poisoning
of trivial members when possible.
- Check msan flags and existence of fields, before dtor sanitizing,
and when determining if aliasing is allowed.
- Testing sanitizing bit fields.
llvm-svn: 246815
This implements basic support for compiling (though not yet assembling
or linking) for a WebAssembly target. Note that ABI details are not yet
finalized, and may change.
Differential Revision: http://reviews.llvm.org/D12002
llvm-svn: 246814
TagDecls (structs, enums, etc.) may have the same name for linkage
purposes of one another; to disambiguate, we add a number to the mangled
named. However, we didn't do this if the TagDecl has a pseudo-name for
linkage purposes (it was defined alongside a DeclaratorDecl or a
TypeNameDecl).
This fixes PR24651.
llvm-svn: 246659
A class without a name for linkage purposes gets a name along the lines
of <unnamed-type-foo> where foo is either the name of a declarator which
defined it (like a variable or field) or a
typedef-name (like a typedef or alias-declaration).
We handled the declarator case correctly but it would fall down during
template instantiation if the declarator didn't share the tag's type.
We failed to handle the typedef-name case at all.
Instead, keep track of the association between the two and keep it up to
date in the face of template instantiation.
llvm-svn: 246469
Proper diagnostic and resolution of mangled names conflicts between C++ methods
and C functions. This patch implements support for functions/methods only;
support for variables is coming separately.
Differential Revision: http://reviews.llvm.org/D11297
llvm-svn: 246438
This patch does two things:
1) Don't error about dllimport/export on thread-local static local variables.
We put those attributes on static locals in dllimport/export functions
implicitly in case the function gets inlined. Now, for TLS variables this
is a problem because we can't import such variables, but it's a benign
problem becase:
2) Make sure we never inline a dllimport function TLS static locals. In fact,
never inline a dllimport function that references a non-imported function
or variable (because these are not defined in the importing library). This
seems to match MSVC's behaviour.
Differential Revision: http://reviews.llvm.org/D12422
llvm-svn: 246338
There was linker problem, and it turns out that it is not always safe
to refer to vtable. If the vtable is used, then we can refer to it
without any problem, but because we don't know when it will be used or
not, we can only check if vtable is external or it is safe to to emit it
speculativly (when class it doesn't have any inline virtual functions).
It should be fixed in the future.
http://reviews.llvm.org/D12385
llvm-svn: 246214
This enables Clang to correctly handle code such as:
struct __declspec(dllexport) S {
int x = 42;
};
where it would otherwise error due to trying to generate the default
constructor before the in-class initializer for x has been parsed.
Differential Revision: http://reviews.llvm.org/D11850
llvm-svn: 245139
We risk iterator invalidation issues if we use a DenseMap to hold the
backing storage for an APValue. Instead, BumpPtrAllocate them and
use APValue * as our DenseMap value.
Also, don't assume that MaterializedGlobalTemporaryMap won't regrow
between when we initially perform a lookup and later on when we actually
try to insert into it.
This fixes PR24289.
Differential Revision: http://reviews.llvm.org/D11629
llvm-svn: 244989
Summary: Poisoning applied to only class members, and before dtors for base class invoked
Implement poisoning of only class members in dtor, as opposed to also
poisoning fields inherited from base classes. Members are poisoned
only once, by the last dtor for a class. Skip poisoning if class has
no fields.
Verify emitted code for derived class with virtual destructor sanitizes
its members only once.
Removed patch file containing extraneous changes.
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D11951
Simplified test cases for use-after-dtor
Summary: Simplified test cases to focus on one feature at time.
Tests updated to align with new emission order for sanitizing
callback.
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D12003
llvm-svn: 244933
Verify emitted code for derived class with virtual destructor sanitizes its members only once.
Changed emission order for dtor callback, so only the last dtor for a class emits the sanitizing callback, while ensuring that class members are poisoned before base class destructors are invoked.
Skip poisoning of members, if class has no fields.
Removed patch file containing extraneous changes.
Summary: Poisoning applied to only class members, and before dtors for base class invoked
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D11951
llvm-svn: 244819
Summary:
The vtable takes its DLL storage class from the class, not the key
function. When they disagree, the vtable won't be exported by the DLL
that defines the key function. The easiest way to ensure that importers
of the class emit their own vtable is to say that the class has no key
function.
Reviewers: hans, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11913
llvm-svn: 244488
This change adds the new unroll metadata "llvm.loop.unroll.enable" which directs
the optimizer to unroll a loop fully if the trip count is known at compile time, and
unroll partially if the trip count is not known at compile time. This differs from
"llvm.loop.unroll.full" which explicitly does not unroll a loop if the trip count is not
known at compile time
With this change "#pragma unroll" generates "llvm.loop.unroll.enable" rather than
"llvm.loop.unroll.full" metadata. This changes the semantics of "#pragma unroll" slightly
to mean "unroll aggressively (fully or partially)" rather than "unroll fully or not at all".
The motivating example for this change was some internal code with a loop marked
with "#pragma unroll" which only sometimes had a compile-time trip count depending
on template magic. When the trip count was a compile-time constant, everything works
as expected and the loop is fully unrolled. However, when the trip count was not a
compile-time constant the "#pragma unroll" explicitly disabled unrolling of the loop(!).
Removing "#pragma unroll" caused the loop to be unrolled partially which was desirable
from a performance perspective.
llvm-svn: 244467
Original class was not marked with inheritance attribute and it causes a crash on codegen.
Differential Revision: http://reviews.llvm.org/D11828
llvm-svn: 244428
MinGW has some pretty strange behvaior around RTTI and
dllimport/dllexport:
- RTTI data is never imported
- RTTI data is only exported if the class has no key function.
llvm-svn: 244266
When a thunk is generated with a call to the original adjusted function,
the thunk appears in the debugger call stack. We want the backend to perform
tail-call optimization on the call, to make it invisible to the debugger.
This fixes PR24235
Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D11476
llvm-svn: 244207
set_size only resets the end pointer and asserts if it is used to grow
the buffer. This would crash when mangling a float with more than 80 bits,
add a test with a ppc double double (128 bits).
Found by inspection.
llvm-svn: 243979
Summary: In addition to checking compiler flags, the front-end also examines the attributes of the destructor definition to ensure that the SanitizeMemory attribute is attached.
Reviewers: eugenis, kcc
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11727
refactored test into new file, revised how function attribute examined
modified test to examine default dtor with and without attribute
removed attribute check
llvm-svn: 243912
Update testcases after LLVM change r243774.
Most of these had no need to check `tag:` field, but did so as a way of
getting to the `name:` field. In a few cases I've converted the `tag:`
checks to `arg:` or `CHECK-NOT: arg:`.
llvm-svn: 243775
new GV (usually NAME.1) instead of the correct NAME of the old GV. Moving comdat
creation after GV replacement solves this. Patch + testcase.
Reviewed by Reid Kleckner.
http://reviews.llvm.org/D11594
llvm-svn: 243525
This will be used for old targets like Android that do not
support ELF TLS models.
Differential Revision: http://reviews.llvm.org/D10524
llvm-svn: 243441
When ‘#pragma clang loop vectorize(assume_safety)’ was specified on a loop other loop hints were lost. The problem is that CGLoopInfo attaches metadata differently than EmitCondBrHints in CGStmt. For do-loops CGLoopInfo attaches metadata to the br in the body block and for while and for loops, the inc block. EmitCondBrHints on the other hand always attaches data to the br in the cond block. When specifying assume_safety CGLoopInfo emits an empty llvm.loop metadata shadowing the metadata in the cond block. Loop transformations like rotate and unswitch would then eliminate the cond block and its non-empty metadata.
This patch unifies both approaches for adding metadata and modifies the existing safety tests to include non-assume_safety loop hints.
llvm-svn: 243315
Generating available_externally vtables for optimizations purposes.
Unfortunatelly ItaniumABI doesn't guarantee that we will be able to
refer to virtual inline method by name.
But when we don't have any inline virtual methods, and key function is
not defined in this TU, we can generate that there will be vtable and
mark it as available_externally.
This is patch will help devirtualize better.
Differential Revision: http://reviews.llvm.org/D11441
llvm-svn: 243090
Sometimes we can provide an initializer for static locals, in which case
we sometimes might need to change the type. Changing the type requires
making a new LLVM GlobalVariable, and in this codepath we were
forgetting to transfer the comdat.
Fixes PR23838.
Patch by Ivan Garramona.
llvm-svn: 242704
Normally, explicit specializations are treated like strong external
definitions. However, MSVC treats explicit specializations of static
data members as weak. MSVC 2013's <regex> implementation has such an
explicit specialization which leads to clang emitting a strong
definition in each translation unit which includes it. Tweak clang's
linkage calculation to give such entities GVA_StrongODR linkage instead.
This fixes PR24165.
llvm-svn: 242592
We shouldn't crash despite the AMD64 ABI not giving clear guidance as to
how to pass around vector types <= 32 bits. Instead, classify such
vectors as INTEGER to be compatible with GCC.
This fixes PR24162.
llvm-svn: 242508
We now use the sanitizer special case list to decide which types to blacklist.
We also support a special blacklist entry for types with a uuid attribute,
which are generally COM types whose virtual tables are defined externally.
Differential Revision: http://reviews.llvm.org/D11096
llvm-svn: 242286
The fix is to remove duplicate copy-initialization of the only memcpy-able struct member and to correct the address of aggregately initialized members in destructors' calls during stack unwinding (in order to obtain address of struct member by using GEP instead of 'bitcast').
Differential Revision: http://reviews.llvm.org/D10990
llvm-svn: 242127
Under the -fsanitize-memory-use-after-dtor (disabled by default) insert
an MSan runtime library call at the end of every destructor.
Patch by Naomi Musgrave.
llvm-svn: 242097
Code in CGCall.cpp that loads up function arguments that need to be
coerced to a different type may in some cases ignore the fact that
the source of the argument is not naturally aligned. This may cause
incorrect code to be generated. In some places in CreateCoercedLoad,
we already have setAlignment calls to address this, but I ran into one
where it was missing, causing wrong code generation on SystemZ.
However, in that location, we do not actually know what alignment of
the source location we can rely on; the callers do not pass anything
to this routine. This is already an issue in other places in
CreateCoercedLoad; and the same problem exists for CreateCoercedStore.
To avoid pessimising code, and to fix the FIXMEs already in place,
this patch also adds an alignment argument to the CreateCoerced*
routines and uses it instead of forcing an alignment of 1. The
callers are changed to pass in the best information they have.
This actually requires changes in a number of existing test cases
since we now get better alignment in many places.
Differential Revision: http://reviews.llvm.org/D11033
llvm-svn: 241898
We were previously creating bit set entries at virtual table offset
sizeof(void*) unconditionally under the Microsoft C++ ABI. This is incorrect
if RTTI data is disabled; in that case the "address point" is at offset
0. This change modifies bit set emission to take into account whether RTTI
data is being emitted.
Also make a start on a blacklisting scheme for records.
Differential Revision: http://reviews.llvm.org/D11048
llvm-svn: 241845
The fix is to emit cleanup for arrays of memcpy-able objects in struct if an exception is thrown later during copy-construction.
Differential Revision: http://reviews.llvm.org/D10989
llvm-svn: 241670
We didn't correctly process the case where a base class is classified as
MEMORY. This would cause us to trip over an assertion.
This fixes PR24020.
Differential Revision: http://reviews.llvm.org/D10907
llvm-svn: 241667
We forgot to run postMerge after decided that the union had to be
classified as MEMORY. This left us with Lo == MEMORY and Hi == SSEUp
which is an invalid combination.
This fixes PR24021.
Differential Revision: http://reviews.llvm.org/D10908
llvm-svn: 241666
Test case trap-fnattr.cpp was failng on clang-ppc64-elf-linux2 because ppc64
sign-extends the i32 return value.
This is a follow-up to r241306.
llvm-svn: 241314
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
It turns out that nullptr pointers to data members act differently in
function templates vs class templates. Class templates use a variable
width representation proportional to the number of fields needed to
materialize it. Function templates always use a single '0' template
parameter. However, using '0' all the time is problematic if the class
uses single or multiple inheritance. In those cases, use -1.
llvm-svn: 241251
Function static variables, typedefs and records (class, struct or union) declared inside
a lexical scope were associated with the function as their parent scope, rather than the
lexical scope they are defined or declared in.
This fixes PR19238
Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D9760
llvm-svn: 241154
When an internal-linkage thunk is code gen'd, CodeGenVTables::emitThunk
will first be called with ForVTable=true (which incorrectly set the
thunk's linkage to available_externally under the Itanium ABI) and later
with ForVTable=false (which reset it to internal). Because we will always
see a call with ForVTable=false, this incorrect linkage never ended up in
the final IR. However, the temporary presence of this linkage caused us
to give such functions a comdat as a result of code introduced in r241102.
To avoid this, check that the thunk is externally visible before giving it
available_externally linkage.
llvm-svn: 241136
Evgeniy Stepanov