In the case of TypedefDecls we set the DeclContext after we imported it.
It turns out, it could lead to null pointer dereferences during the
cleanup part of a failed import.
This patch demonstrates this issue and fixes it by checking if the
DeclContext is available or not.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D102640
This patch is the Part-1 (FE Clang) implementation of HW Exception handling.
This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).
This is the first step of this project; only X86_64 target is enabled in this patch.
Compiler options:
For clang-cl.exe, the option is -EHa, the same as MSVC.
For clang.exe, the extra option is -fasync-exceptions,
plus -triple x86_64-windows -fexceptions and -fcxx-exceptions as usual.
NOTE:: Without the -EHa or -fasync-exceptions, this patch is a NO-DIFF change.
The rules for C code:
For C-code, one way (MSVC approach) to achieve SEH -EHa semantic is to follow
three rules:
* First, no exception can move in or out of _try region., i.e., no "potential
faulty instruction can be moved across _try boundary.
* Second, the order of exceptions for instructions 'directly' under a _try
must be preserved (not applied to those in callees).
* Finally, global states (local/global/heap variables) that can be read
outside of _try region must be updated in memory (not just in register)
before the subsequent exception occurs.
The impact to C++ code:
Although SEH is a feature for C code, -EHa does have a profound effect on C++
side. When a C++ function (in the same compilation unit with option -EHa ) is
called by a SEH C function, a hardware exception occurs in C++ code can also
be handled properly by an upstream SEH _try-handler or a C++ catch(...).
As such, when that happens in the middle of an object's life scope, the dtor
must be invoked the same way as C++ Synchronous Exception during unwinding
process.
Design:
A natural way to achieve the rules above in LLVM today is to allow an EH edge
added on memory/computation instruction (previous iload/istore idea) so that
exception path is modeled in Flow graph preciously. However, tracking every
single memory instruction and potential faulty instruction can create many
Invokes, complicate flow graph and possibly result in negative performance
impact for downstream optimization and code generation. Making all
optimizations be aware of the new semantic is also substantial.
This design does not intend to model exception path at instruction level.
Instead, the proposed design tracks and reports EH state at BLOCK-level to
reduce the complexity of flow graph and minimize the performance-impact on CPP
code under -EHa option.
One key element of this design is the ability to compute State number at
block-level. Our algorithm is based on the following rationales:
A _try scope is always a SEME (Single Entry Multiple Exits) region as jumping
into a _try is not allowed. The single entry must start with a seh_try_begin()
invoke with a correct State number that is the initial state of the SEME.
Through control-flow, state number is propagated into all blocks. Side exits
marked by seh_try_end() will unwind to parent state based on existing
SEHUnwindMap[].
Note side exits can ONLY jump into parent scopes (lower state number).
Thus, when a block succeeds various states from its predecessors, the lowest
State triumphs others. If some exits flow to unreachable, propagation on those
paths terminate, not affecting remaining blocks.
For CPP code, object lifetime region is usually a SEME as SEH _try.
However there is one rare exception: jumping into a lifetime that has Dtor but
has no Ctor is warned, but allowed:
Warning: jump bypasses variable with a non-trivial destructor
In that case, the region is actually a MEME (multiple entry multiple exits).
Our solution is to inject a eha_scope_begin() invoke in the side entry block to
ensure a correct State.
Implementation:
Part-1: Clang implementation described below.
Two intrinsic are created to track CPP object scopes; eha_scope_begin() and eha_scope_end().
_scope_begin() is immediately added after ctor() is called and EHStack is pushed.
So it must be an invoke, not a call. With that it's also guaranteed an
EH-cleanup-pad is created regardless whether there exists a call in this scope.
_scope_end is added before dtor(). These two intrinsics make the computation of
Block-State possible in downstream code gen pass, even in the presence of
ctor/dtor inlining.
Two intrinsic, seh_try_begin() and seh_try_end(), are added for C-code to mark
_try boundary and to prevent from exceptions being moved across _try boundary.
All memory instructions inside a _try are considered as 'volatile' to assure
2nd and 3rd rules for C-code above. This is a little sub-optimized. But it's
acceptable as the amount of code directly under _try is very small.
Part-2 (will be in Part-2 patch): LLVM implementation described below.
For both C++ & C-code, the state of each block is computed at the same place in
BE (WinEHPreparing pass) where all other EH tables/maps are calculated.
In addition to _scope_begin & _scope_end, the computation of block state also
rely on the existing State tracking code (UnwindMap and InvokeStateMap).
For both C++ & C-code, the state of each block with potential trap instruction
is marked and reported in DAG Instruction Selection pass, the same place where
the state for -EHsc (synchronous exceptions) is done.
If the first instruction in a reported block scope can trap, a Nop is injected
before this instruction. This nop is needed to accommodate LLVM Windows EH
implementation, in which the address in IPToState table is offset by +1.
(note the purpose of that is to ensure the return address of a call is in the
same scope as the call address.
The handler for catch(...) for -EHa must handle HW exception. So it is
'adjective' flag is reset (it cannot be IsStdDotDot (0x40) that only catches
C++ exceptions).
Suppress push/popTerminate() scope (from noexcept/noTHrow) so that HW
exceptions can be passed through.
Original llvm-dev [RFC] discussions can be found in these two threads below:
https://lists.llvm.org/pipermail/llvm-dev/2020-March/140541.htmlhttps://lists.llvm.org/pipermail/llvm-dev/2020-April/141338.html
Differential Revision: https://reviews.llvm.org/D80344/new/
1.[bool, char, short] bitfields have the same alignment as unsigned int
2.Adjust alignment on typedef field decls/honor align attribute
3.Fix alignment for scoped enum class
4.Long long bitfield has 4bytes alignment and StorageUnitSize under 32 bit
compile mode
Differential Revision: https://reviews.llvm.org/D87029
In working on p0388 (ary[N] -> ary[] conversion), I discovered neither
use of UnwrapSimilarArrayTypes used the return value. So let's nuke
it.
Differential Revision: https://reviews.llvm.org/D102480
For a type-constraint in a lambda signature, this makes the lambda
contain an unexpanded pack; for requirements in a requires-expressions
it makes the requires-expression contain an unexpanded pack; otherwise
it's invalid.
properly track that it has constraints.
Previously an instantiation of a constrained generic lambda would behave
as if unconstrained because we incorrectly cached a "has no constraints"
value that we computed before the constraints from 'auto' parameters
were attached.
It doesn't really make sense to emit language specific diagnostics
in a discarded statement, and suppressing these diagnostics results in a
programming pattern that many users will feel is quite useful.
Basically, this makes sure we only emit errors from the 'true' side of a
'constexpr if'.
It does this by making the ExprEvaluatorBase type have an opt-in option
as to whether it should visit discarded cases.
Differential Revision: https://reviews.llvm.org/D102251
Non-comprehensive list of cases:
* Dumping template arguments;
* Corresponding parameter contains a deduced type;
* Template arguments are for a DeclRefExpr that hadMultipleCandidates()
Type information is added in the form of prefixes (u8, u, U, L),
suffixes (U, L, UL, LL, ULL) or explicit casts to printed integral template
argument, if MSVC codeview mode is disabled.
Differential revision: https://reviews.llvm.org/D77598
Currently clang does not emit device template variables
instantiated only in host functions, however, nvcc is
able to do that:
https://godbolt.org/z/fneEfferY
This patch fixes this issue by refactoring and extending
the existing mechanism for emitting static device
var ODR-used by host only. Basically clang records
device variables ODR-used by host code and force
them to be emitted in device compilation. The existing
mechanism makes sure these device variables ODR-used
by host code are added to llvm.compiler-used, therefore
they are guaranteed not to be deleted.
It also fixes non-ODR-use of static device variable by host code
causing static device variable to be emitted and registered,
which should not.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D102237
This patch fixes various issues with our prior `declare target` handling
and extends it to support `omp begin declare target` as well.
This started with PR49649 in mind, trying to provide a way for users to
avoid the "ref" global use introduced for globals with internal linkage.
From there it went down the rabbit hole, e.g., all variables, even
`nohost` ones, were emitted into the device code so it was impossible to
determine if "ref" was needed late in the game (based on the name only).
To make it really useful, `begin declare target` was needed as it can
carry the `device_type`. Not emitting variables eagerly had a ripple
effect. Finally, the precedence of the (explicit) declare target list
items needed to be taken into account, that meant we cannot just look
for any declare target attribute to make a decision. This caused the
handling of functions to require fixup as well.
I tried to clean up things while I was at it, e.g., we should not "parse
declarations and defintions" as part of OpenMP parsing, this will always
break at some point. Instead, we keep track what region we are in and
act on definitions and declarations instead, this is what we do for
declare variant and other begin/end directives already.
Highlights:
- new diagnosis for restrictions specificed in the standard,
- delayed emission of globals not mentioned in an explicit
list of a declare target,
- omission of `nohost` globals on the host and `host` globals on the
device,
- no explicit parsing of declarations in-between `omp [begin] declare
variant` and the corresponding end anymore, regular parsing instead,
- precedence for explicit mentions in `declare target` lists over
implicit mentions in the declaration-definition-seq, and
- `omp allocate` declarations will now replace an earlier emitted
global, if necessary.
---
Notes:
The patch is larger than I hoped but it turns out that most changes do
on their own lead to "inconsistent states", which seem less desirable
overall.
After working through this I feel the standard should remove the
explicit declare target forms as the delayed emission is horrible.
That said, while we delay things anyway, it seems to me we check too
often for the current status even though that is often not sufficient to
act upon. There seems to be a lot of duplication that can probably be
trimmed down. Eagerly emitting some things seems pretty weak as an
argument to keep so much logic around.
---
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D101030
This implements the flag proposed in RFC
http://lists.llvm.org/pipermail/cfe-dev/2020-August/066437.html.
The goal is to add a way to override the default target C++ ABI through a
compiler flag. This makes it easier to test and transition between different
C++ ABIs through compile flags rather than build flags.
In this patch:
- Store -fc++-abi= in a LangOpt. This isn't stored in a CodeGenOpt because
there are instances outside of codegen where Clang needs to know what the
ABI is (particularly through ASTContext::createCXXABI), and we should be
able to override the target default if the flag is provided at that point.
- Expose the existing ABIs in TargetCXXABI as values that can be passed
through this flag.
- Create a .def file for these ABIs to make it easier to check flag values.
- Add an error for diagnosing bad ABI flag values.
Differential Revision: https://reviews.llvm.org/D85802
Warn when a declaration uses an identifier that doesn't obey the reserved
identifier rule from C and/or C++.
Differential Revision: https://reviews.llvm.org/D93095
The code example:
```
constexpr const char kEta[] = "Eta";
template <const char*, typename T> class Column {};
using quick = Column<kEta,double>;
void lookup() {
quick c1;
c1.ls();
}
```
emits error: no member named 'ls' in 'Column<&kEta, double>'. The patch fixes
the printed type name by not printing the ampersand for array types.
Differential Revision: https://reviews.llvm.org/D36368
Reverts parts of https://reviews.llvm.org/D17183, but keeps the
resetDataLayout() API and adds an assert that checks that datalayout string and
user label prefix are in sync.
Approach 1 in https://reviews.llvm.org/D17183#2653279
Reduces number of TUs build for 'clang-format' from 689 to 575.
I also implemented approach 2 in D100764. If someone feels motivated
to make us use DataLayout more, it's easy to revert this change here
and go with D100764 instead. I don't plan on doing more work in this
area though, so I prefer going with the smaller, more self-consistent change.
Differential Revision: https://reviews.llvm.org/D100776
Default address space (applies when no explicit address space was
specified) maps to generic (4) address space.
Added SYCL named address spaces `sycl_global`, `sycl_local` and
`sycl_private` defined as sub-sets of the default address space.
Static variables without address space now reside in global address
space when compile for SPIR target, unless they have an explicit address
space qualifier in source code.
Differential Revision: https://reviews.llvm.org/D89909
In some cases, we want to provide the alias name for the clang builtins.
For example, the arguments must be constant integers for some RISC-V builtins.
If we use wrapper functions, we could not constrain the arguments be constant
integer. This attribute is used to achieve the purpose.
Besides this, use `clang_builtin_alias` is more efficient than using
wrapper functions. We use this attribute to deal with test time issue
reported in https://bugs.llvm.org/show_bug.cgi?id=49962.
In our downstream testing, it could decrease the testing time from 6.3
seconds to 3.7 seconds for vloxei.c test.
Differential Revision: https://reviews.llvm.org/D100611
The following program winds up with
D->getDefaultArgStorage().getInheritedFrom() == nullptr
during dumping the TemplateTemplateParmDecl corresponding to the
template parameter of i.
template <typename>
struct R;
template <template <typename> class = R>
void i();
This patch fixes the null pointer dereference.
Overflows are never fun.
In most cases (in most of the code), they are rare,
because usually you e.g. don't have as many elements.
However, it's exceptionally easy to fall into this pitfail
in code that deals with images, because, assuming 4-channel 32-bit FP data,
you need *just* ~269 megapixel image to case an overflow
when computing at least the total byte count.
In [[ https://github.com/darktable-org/darktable | darktable ]], there is a *long*, painful history of dealing with such bugs:
* https://github.com/darktable-org/darktable/pull/7740
* https://github.com/darktable-org/darktable/pull/7419
* eea1989f2c
* 70626dd95b
* https://github.com/darktable-org/darktable/pull/670
* 38c69fb1b2
and yet they clearly keep resurfacing still.
It would be immensely helpful to have a diagnostic for those patterns,
which is what this change proposes.
Currently, i only diagnose the most obvious case, where multiplication
is directly widened with no other expressions inbetween,
(i.e. `long r = (int)a * (int)b` but not even e.g. `long r = ((int)a * (int)b)`)
however that might be worth relaxing later.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D93822
The existing Windows Itanium patches for dllimport/export
behaviour w.r.t vtables/rtti can't be adopted for PS4 due to
backwards compatibility reasons (see comments on
https://reviews.llvm.org/D90299).
This commit adds our PS4 scheme for this to Clang.
Differential Revision: https://reviews.llvm.org/D93203
The function did not handle every case. In some cases this
caused assertion failure.
After the fix the function returns DependentTy if the exact
return type can not be determined.
It seems that clang itself does not call the function in the
affected cases but some checker or other code may call it.
Reviewed By: hokein
Differential Revision: https://reviews.llvm.org/D95244
This implements C-style type conversions for matrix types, as specified
in clang/docs/MatrixTypes.rst.
Fixes PR47141.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D99037
I have been trying to statically find and analyze all calls to heap
allocation functions to determine how many of them use sizes known at
compile time vs only at runtime. While doing so I saw that quite a few
projects use replaceable function pointers for heap allocation and noticed
that clang was not able to annotate functions pointers with alloc_size.
I have changed the Sema checks to allow alloc_size on all function pointers
and typedefs for function pointers now and added checks that these
attributes are propagated to the LLVM IR correctly.
With this patch we can also compute __builtin_object_size() for calls to
allocation function pointers with the alloc_size attribute.
Reviewed By: aaron.ballman, erik.pilkington
Differential Revision: https://reviews.llvm.org/D55212
omp_is_initial_device() is marked as a built-in function in the current
compiler, and user code guarded by this call may be optimized away,
resulting in undesired behavior in some cases. This patch provides a
possible fix for such cases by defining the routine as a variant
function and removing it from builtin list.
Differential Revision: https://reviews.llvm.org/D99447
Programmers would like to be able to test direct methods by calling them from a
different linkage unit or mocking them, both of which are impossible. This
patch adds a flag that effectively disables the attribute, which will fix this
when enabled in testable builds. rdar://71190891
Differential revision: https://reviews.llvm.org/D95845
(PR49478)
As ArrayType::ArrayType mentioned in clang/lib/AST/Type.cpp, a
DependentSizedArrayType might not have size expression because it it
used as the type of a dependent array of unknown bound with a dependent
braced initializer.
Thus, I add a check when mangling array of that type.
This should fix https://bugs.llvm.org/show_bug.cgi?id=49478
Reviewed By: Richard Smith - zygoloid
Differential Revision: https://reviews.llvm.org/D99407
We do the import of the member enum specialization similarly to as we do
with member CXXRecordDecl specialization.
Differential Revision: https://reviews.llvm.org/D99421
On z/OS there is a hard limitation on on the maximum requestable alignment in aligned attribute for static variables. We need to truncate values greater than that.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D98864
Zero length bitfield alignment is not respected if they are leading members on z/OS target.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D98890
Update ASTImporter to import value of FieldDecl::getCapturedVLAType.
Reviewed By: shafik, martong
Differential Revision: https://reviews.llvm.org/D99062
Objective-C apparently allows name conflicts between instance and class
properties, so this is valid code:
```
@protocol DupProp
@property (class, readonly) int prop;
@property (readonly) int prop;
@end
```
The ASTImporter however isn't aware of this and will consider the two properties
as if they are the same property because it just compares their name and types.
This causes that when importing both properties we only end up with one property
(whatever is imported first from what I can see).
Beside generating a different AST this also leads to a bunch of asserts and
crashes as we still correctly import the two different getters for both
properties (the import code for methods does the correct check where it
differentiated between instance and class methods). As one of the setters will
not have its associated ObjCPropertyDecl imported, any call to
`ObjCMethodDecl::findPropertyDecl` will just lead to an assert or crash.
Fixes rdar://74322659
Reviewed By: shafik, kastiglione
Differential Revision: https://reviews.llvm.org/D99077
There was only an `Import` function for `QualType` but not for `Type`.
For correct import of some AST nodes where not `QualType` is used
an import of `Type *` is needed. (It is the case with
`FieldDecl::getCapturedVLAType`.)
Reviewed By: shafik, teemperor, martong
Differential Revision: https://reviews.llvm.org/D98951
It is possible that imported `SourceLocExpr` can cause not expected behavior (if `__builtin_LINE()` is used together with `__LINE__` for example) but still it may be worth to import these because some projects use it.
Reviewed By: teemperor
Differential Revision: https://reviews.llvm.org/D98876
C functions may be declared and defined in different prototypes like below. This patch unifies the checks for mangling names in symbol linkage name emission and debug linkage name emission so that the two names are consistent.
static int go(int);
static int go(a) int a;
{
return a;
}
Test Plan:
Differential Revision: https://reviews.llvm.org/D98799
Added basic parsing/sema/serialization support to extend the
existing 'destroy' clause for use with the 'interop' directive.
Differential Revision: https://reviews.llvm.org/D98834
Alexey Bader