Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in as the function attribute
"null-pointer-is-valid"="true".
This CL only adds the attribute on the function.
It also strips "nonnull" attributes from function arguments but
keeps the related warnings unchanged.
Corresponding LLVM change rL336613 already updated the
optimizations to not treat null pointer dereferencing
as undefined if the attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: jyknight
Subscribers: drinkcat, xbolva00, cfe-commits
Differential Revision: https://reviews.llvm.org/D47894
llvm-svn: 337433
Currently clang set kernel calling convention for CUDA/HIP after
arranging function, which causes incorrect kernel function type since
it depends on calling convention.
This patch moves setting kernel convention before arranging
function.
Differential Revision: https://reviews.llvm.org/D47733
llvm-svn: 334457
Introduced CreateMemTempWithoutCast and CreateTemporaryAllocaWithoutCast to emit alloca
without casting to default addr space.
ActiveFlag is a temporary variable emitted for clean up. It is defined as AllocaInst* type and there is
a cast to AlllocaInst in SetActiveFlag. An alloca casted to generic pointer causes assertion in
SetActiveFlag.
Since there is only load/store of ActiveFlag, it is safe to use the original alloca, therefore use
CreateMemTempWithoutCast is called.
Differential Revision: https://reviews.llvm.org/D47099
llvm-svn: 332982
lifetime.start/end expects pointer argument in alloca address space.
However in C++ a temporary variable is in default address space.
This patch changes API CreateMemTemp and CreateTempAlloca to
get the original alloca instruction and pass it lifetime.start/end.
It only affects targets with non-zero alloca address space.
Differential Revision: https://reviews.llvm.org/D45900
llvm-svn: 332593
FunctionProtoType.
We previously re-evaluated the expression each time we wanted to know whether
the type is noexcept or not. We now evaluate the expression exactly once.
This is not quite "no functional change": it fixes a crasher bug during AST
deserialization where we would try to evaluate the noexcept specification in a
situation where we have not deserialized sufficient portions of the AST to
permit such evaluation.
llvm-svn: 331428
As suggested in the post-commit thread for rL331056, we should match these
clang options with the established vocabulary of the corresponding sanitizer
option. Also, the use of 'strict' is well-known for these kinds of knobs,
and we can improve the descriptive text in the docs.
So this intends to match the logic of D46135 but only change the words.
Matching LLVM commit to match this spelling of the attribute to follow shortly.
Differential Revision: https://reviews.llvm.org/D46236
llvm-svn: 331209
As discussed in the post-commit thread for:
rL330437 ( http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180423/545906.html )
We need a way to opt-out of a float-to-int-to-float cast optimization because too much
existing code relies on the platform-specific undefined result of those casts when the
float-to-int overflows.
The LLVM changes associated with adding this function attribute are here:
rL330947
rL330950
rL330951
Also as suggested, I changed the LLVM doc to mention the specific sanitizer flag that
catches this problem:
rL330958
Differential Revision: https://reviews.llvm.org/D46135
llvm-svn: 331041
function if a function delegates to another function.
Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.
This reapplies r331016, which was reverted in r331019 because it caused
an assertion to fail in EmitDelegateCallArg on a windows bot. I made
changes to EmitDelegateCallArg so that it doesn't try to deactivate
cleanups for structs that have trivial destructors (cleanups for those
structs are never pushed to the cleanup stack in EmitParmDecl).
rdar://problem/39194693
Differential Revision: https://reviews.llvm.org/D45382
llvm-svn: 331020
function if a function delegates to another function.
Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.
rdar://problem/39194693
Differential Revision: https://reviews.llvm.org/D45382
llvm-svn: 331016
have a non-trivial destructor.
This fixes a bug introduced in r328731 where CodeGen emits calls to
synthesized destructors for non-trivial C structs in C++ mode when the
struct passed to EmitCallArg doesn't have a non-trivial destructor.
Under Microsoft's ABI, ASTContext::isParamDestroyedInCallee currently
always returns true, so it's necessary to check whether the struct has a
non-trivial destructor before pushing a cleanup in EmitCallArg.
This fixes PR37146.
llvm-svn: 330304
the tail padding is not reused.
We track on the AggValueSlot (and through a couple of other
initialization actions) whether we're dealing with an object that might
share its tail padding with some other object, so that we can avoid
emitting stores into the tail padding if that's the case. We still
widen stores into tail padding when we can do so.
Differential Revision: https://reviews.llvm.org/D45306
llvm-svn: 329342
This reverts r328795 which introduced an issue with referencing __global__
function templates. More details in the original review D44747.
llvm-svn: 329099
Summary:
The following class hierarchy requires that we be able to emit a
this-adjusting thunk for B::foo in C's vftable:
struct Incomplete;
struct A {
virtual A* foo(Incomplete p) = 0;
};
struct B : virtual A {
void foo(Incomplete p) override;
};
struct C : B { int c; };
This TU is valid, but lacks a definition of 'Incomplete', which makes it
hard to build a thunk for the final overrider, B::foo.
Before this change, Clang gives up attempting to emit the thunk, because
it assumes that if the parameter types are incomplete, it must be
emitting the thunk for optimization purposes. This is untrue for the MS
ABI, where the implementation of B::foo has no idea what thunks C's
vftable may require. Clang needs to emit the thunk without necessarily
having access to the complete prototype of foo.
This change makes Clang emit a musttail variadic call when it needs such
a thunk. I call these "unprototyped" thunks, because they only prototype
the "this" parameter, which must always come first in the MS C++ ABI.
These thunks work, but they create ugly LLVM IR. If the call to the
thunk is devirtualized, it will be a call to a bitcast of a function
pointer. Today, LLVM cannot inline through such a call, but I want to
address that soon, because we also use this pattern for virtual member
pointer thunks.
This change also implements an old FIXME in the code about reusing the
thunk's computed CGFunctionInfo as much as possible. Now we don't end up
computing the thunk's mangled name and arranging it's prototype up to
around three times.
Fixes PR25641
Reviewers: rjmccall, rsmith, hans
Subscribers: Prazek, cfe-commits
Differential Revision: https://reviews.llvm.org/D45112
llvm-svn: 329009
This patch sets target specific calling convention for CUDA kernels in IR.
Patch by Greg Rodgers.
Revised and lit test added by Yaxun Liu.
Differential Revision: https://reviews.llvm.org/D44747
llvm-svn: 328795
ObjC and ObjC++ pass non-trivial structs in a way that is incompatible
with each other. For example:
typedef struct {
id f0;
__weak id f1;
} S;
// this code is compiled in c++.
extern "C" {
void foo(S s);
}
void caller() {
// the caller passes the parameter indirectly and destructs it.
foo(S());
}
// this function is compiled in c.
// 'a' is passed directly and is destructed in the callee.
void foo(S a) {
}
This patch fixes the incompatibility by passing and returning structs
with __strong or weak fields using the C ABI in C++ mode. __strong and
__weak fields in a struct do not cause the struct to be destructed in
the caller and __strong fields do not cause the struct to be passed
indirectly.
Also, this patch fixes the microsoft ABI bug mentioned here:
https://reviews.llvm.org/D41039?id=128767#inline-364710
rdar://problem/38887866
Differential Revision: https://reviews.llvm.org/D44908
llvm-svn: 328731
The patch adds nocf_check target independent attribute for disabling checks that were enabled by cf-protection flag.
The attribute can be appertained to functions and function pointers.
Attribute name follows GCC's similar attribute name.
Differential Revision: https://reviews.llvm.org/D41880
llvm-svn: 327768
Before this, we'd only emit lifetime.ends for these temps in
non-exceptional paths. This potentially made our stack larger than it
needed to be for any code that follows an EH cleanup. e.g. in
```
struct Foo { char cs[32]; };
void escape(void *);
struct Bar { ~Bar() { char cs[64]; escape(cs); } };
Foo getFoo();
void baz() {
Bar b;
getFoo();
}
```
baz() would require 96 bytes of stack, since the temporary from getFoo()
only had a lifetime.end on the non-exceptional path.
This also makes us keep hold of the Value* returned by
EmitLifetimeStart, so we don't have to remake it later.
llvm-svn: 326988
The indirect function argument is in alloca address space in LLVM IR. However,
during Clang codegen for C++, the address space of indirect function argument
should match its address space in the source code, i.e., default addr space, even
for indirect argument. This is because destructor of the indirect argument may
be called in the caller function, and address of the indirect argument may be
taken, in either case the indirect function argument is expected to be in default
addr space, not the alloca address space.
Therefore, the indirect function argument should be mapped to the temp var
casted to default address space. The caller will cast it to alloca addr space
when passing it to the callee. In the callee, the argument is also casted to the
default address space and used.
CallArg is refactored to facilitate this fix.
Differential Revision: https://reviews.llvm.org/D34367
llvm-svn: 326946
EmitLifetimeStart returns a non-null `size` pointer if it actually
emits a lifetime.start. Later in this function, we use `tempSize`'s
nullness to determine whether or not we should emit a lifetime.end.
llvm-svn: 326844
The patch fixes a number of bugs related to parameter indexing in
attributes:
* Parameter indices in some attributes (argument_with_type_tag,
pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
and ownership_returns) are specified in source as one-origin
including any C++ implicit this parameter, were stored as
zero-origin excluding any this parameter, and were erroneously
printing (-ast-print) and confusingly dumping (-ast-dump) as the
stored values.
* For alloc_size, the C++ implicit this parameter was not subtracted
correctly in Sema, leading to assert failures or to silent failures
of __builtin_object_size to compute a value.
* For argument_with_type_tag, pointer_with_type_tag, and
ownership_returns, the C++ implicit this parameter was not added
back to parameter indices in some diagnostics.
This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes. ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed. Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*]. This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument. The only exception is xray_log_args's
argument, which is encoded as a count not an index.
Differential Revision: https://reviews.llvm.org/D43248
llvm-svn: 326602
This makes it easier to debug crashes and hangs in block functions since
users can easily find out where the block is called from. The option
doesn't disable tail-calls from non-escaping blocks since non-escaping
blocks are not as hard to debug as escaping blocks.
rdar://problem/35758207
Differential Revision: https://reviews.llvm.org/D43841
llvm-svn: 326530
objc_msgSend_stret takes a hidden parameter for the returned structure's
address for the construction. When the function signature is rewritten
for the inalloca passing, the return type is no longer marked as
indirect but rather inalloca stret. This enhances the test for the
indirect return to check for that case as well. This fixes the
incorrect return classification for Windows x86.
llvm-svn: 326362
ARC mode.
Declaring __strong pointer fields in structs was not allowed in
Objective-C ARC until now because that would make the struct non-trivial
to default-initialize, copy/move, and destroy, which is not something C
was designed to do. This patch lifts that restriction.
Special functions for non-trivial C structs are synthesized that are
needed to default-initialize, copy/move, and destroy the structs and
manage the ownership of the objects the __strong pointer fields point
to. Non-trivial structs passed to functions are destructed in the callee
function.
rdar://problem/33599681
Differential Revision: https://reviews.llvm.org/D41228
llvm-svn: 326307
Summary:
OpenCL 2.0 specification defines '-cl-uniform-work-group-size' option,
which requires that the global work-size be a multiple of the work-group
size specified to clEnqueueNDRangeKernel and allows optimizations that
are made possible by this restriction.
The patch introduces the support of this option.
To keep information about whether an OpenCL kernel has uniform work
group size or not, clang generates 'uniform-work-group-size' function
attribute for every kernel:
- "uniform-work-group-size"="true" for OpenCL 1.2 and lower,
- "uniform-work-group-size"="true" for OpenCL 2.0 and higher if
'-cl-uniform-work-group-size' option was specified,
- "uniform-work-group-size"="false" for OpenCL 2.0 and higher if no
'-cl-uniform-work-group-size' options was specified.
If the function is not an OpenCL kernel, 'uniform-work-group-size'
attribute isn't generated.
Patch by: krisb
Reviewers: yaxunl, Anastasia, b-sumner
Reviewed By: yaxunl, Anastasia
Subscribers: nhaehnle, yaxunl, Anastasia, cfe-commits
Differential Revision: https://reviews.llvm.org/D43570
llvm-svn: 325771
As reported here: https://bugs.llvm.org/show_bug.cgi?id=36301
The issue is that the 'use' causes the plain declaration to emit
the attributes to LLVM-IR. However, if the definition added it
later, these would silently disappear.
This commit extracts that logic to its own function in CodeGenModule,
and has the attribute-applications done during 'definition' update
the attributes properly.
Differential Revision: https://reviews.llvm.org/D43095
llvm-svn: 324907
Summary:
Fixes PR36247, which is where WinEHPrepare replaces inline asm in
funclets with unreachable.
Make getBundlesForFunclet return by value to simplify some call sites.
Reviewers: smeenai, majnemer
Subscribers: eraman, cfe-commits
Differential Revision: https://reviews.llvm.org/D43033
llvm-svn: 324689
This change reduces the live range of the loaded function pointer,
resulting in a slight code size decrease (~10KB in clang), and also
improves the security of CFI for virtual calls by making it less
likely that the function pointer will be spilled, and ensuring that
it is not spilled across a function call boundary.
Fixes PR35353.
Differential Revision: https://reviews.llvm.org/D42725
llvm-svn: 324286
The 'trivial_abi' attribute can be applied to a C++ class, struct, or
union. It makes special functions of the annotated class (the destructor
and copy/move constructors) to be trivial for the purpose of calls and,
as a result, enables the annotated class or containing classes to be
passed or returned using the C ABI for the underlying type.
When a type that is considered trivial for the purpose of calls despite
having a non-trivial destructor (which happens only when the class type
or one of its subobjects is a 'trivial_abi' class) is passed to a
function, the callee is responsible for destroying the object.
For more background, see the discussions that took place on the mailing
list:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/055955.htmlhttp://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180101/thread.html#214043
rdar://problem/35204524
Differential Revision: https://reviews.llvm.org/D41039
llvm-svn: 324269
When a function taking transparent union is declared as taking one of
union members earlier in the translation unit, clang would hit an
"Invalid cast" assertion during EmitFunctionProlog. This case
corresponds to function f1 in test/CodeGen/transparent-union-redecl.c.
We decided to cast i32 to union because after merging function
declarations function parameter type becomes int,
CGFunctionInfo::ArgInfo type matches with ABIArgInfo type, so we decide
it is a trivial case. But these types should also be castable to
parameter declaration type which is not the case here.
Now the fix is in converting from ABIArgInfo type to VarDecl type and using
argument demotion when necessary.
Additional tests in Sema/transparent-union.c capture current behavior and make
sure there are no regressions.
rdar://problem/34949329
Reviewers: rjmccall, rafael
Reviewed By: rjmccall
Subscribers: aemerson, cfe-commits, kristof.beyls, ahatanak
Differential Revision: https://reviews.llvm.org/D41311
llvm-svn: 323156
As @rjmccall suggested in D40023, we can get rid of
ABIInfo::shouldSignExtUnsignedType (used to handle cases like the Mips calling
convention where 32-bit integers are always sign extended regardless of the
sign of the type) by adding a SignExt field to ABIArgInfo. In the common case,
this new field is set automatically by ABIArgInfo::getExtend based on the sign
of the type. For targets that want greater control, they can use
ABIArgInfo::getSignExtend or ABIArgInfo::getZeroExtend when necessary. This
change also cleans up logic in CGCall.cpp.
There is no functional change intended in this patch, and all tests pass
unchanged. As noted in D40023, Mips might want to sign-extend unsigned 32-bit
integer return types. A future patch might modify
MipsABIInfo::classifyReturnType to use MipsABIInfo::extendType.
Differential Revision: https://reviews.llvm.org/D41999
llvm-svn: 322396
Stephen Kelly