This patch changes errors in `SmallVector::grow` that are independent of
memory capacity to be reported using report_fatal_error or
std::length_error instead of report_bad_alloc_error, which falsely signals
an OOM.
It also cleans up a few related things:
- makes report_bad_alloc_error to print the failure reason passed
to it.
- fixes the documentation to indicate that report_bad_alloc_error
calls `abort()` not "an assertion"
- uses a consistent name for the size/capacity argument to `grow`
and `grow_pod`
Reviewed By: mehdi_amini, MaskRay
Differential Revision: https://reviews.llvm.org/D86892
Summary:
This was introduced in dda3c19a36 aka D77621.
The unused template instantiation causes a warning on 32 bit systems
about truncating a uint64_t to 32-bit size_t.
Reviewed By: dblaikie, smeenai
Differential Revision: https://reviews.llvm.org/D79214
SmallVector currently uses 32bit integers for size and capacity to reduce
sizeof(SmallVector). This limits the number of elements to UINT32_MAX.
For a SmallVector<char>, this limits the SmallVector size to only 4GB.
Buffering bitcode output uses SmallVector<char>, but needs >4GB output.
This changes SmallVector size and capacity to conditionally use word-size
integers if the element type is small (<4 bytes). For larger elements types,
the vector size can reach ~16GB with 32bit size.
Making this conditional on the element type provides both the smaller
sizeof(SmallVector) for larger types which are unlikely to grow so large,
and supports larger capacities for smaller element types.
This recommit fixes the same template being instantiated twice on platforms
where uintptr_t is the same as uint32_t.
SmallVector currently uses 32bit integers for size and capacity to reduce
sizeof(SmallVector). This limits the number of elements to UINT32_MAX.
For a SmallVector<char>, this limits the SmallVector size to only 4GB.
Buffering bitcode output uses SmallVector<char>, but needs >4GB output.
This changes SmallVector size and capacity to conditionally use word-size
integers if the element type is small (<4 bytes). For larger elements types,
the vector size can reach ~16GB with 32bit size.
Making this conditional on the element type provides both the smaller
sizeof(SmallVector) for larger types which are unlikely to grow so large,
and supports larger capacities for smaller element types.
Context:
/// Double the size of the allocated memory, guaranteeing space for at
/// least one more element or MinSize if specified.
void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); }
void push_back(const T &Elt) {
if (LLVM_UNLIKELY(this->size() >= this->capacity()))
this->grow();
memcpy(reinterpret_cast<void *>(this->end()), &Elt, sizeof(T));
this->set_size(this->size() + 1);
}
When grow is called in push_back() without a MinSize specified, this is
relying on the guarantee of space for at least one more element.
There is an edge case bug where the SmallVector is already at its maximum size
and push_back() calls grow() with default MinSize of zero. Grow is unable to
provide space for one more element, but push_back() assumes the additional
element it will be available. This can result in silent memory corruption, as
this->end() will be an invalid pointer and the program may continue executing.
Another alternative to fix would be to remove the default argument from
grow(), which would mean several changing grow() to grow(this->size()+1)
in several places.
No test case added because it would require allocating ~4GB.
Reviewers: echristo
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77601
SmallVector currently uses 32bit integers for size and capacity to reduce
sizeof(SmallVector). This limits the number of elements to UINT32_MAX.
For a SmallVector<char>, this limits the SmallVector size to only 4GB.
Buffering bitcode output uses SmallVector<char>, but needs >4GB output.
This changes SmallVector size and capacity to conditionally use word-size
integers if the element type is small (<4 bytes). For larger elements types,
the vector size can reach ~16GB with 32bit size.
Making this conditional on the element type provides both the smaller
sizeof(SmallVector) for larger types which are unlikely to grow so large,
and supports larger capacities for smaller element types.
This change also includes a fix for the bug where a SmallVector with 32bit
size has reached UINT32_MAX elements, and cannot provide guaranteed growth.
Context:
// Double the size of the allocated memory, guaranteeing space for at
// least one more element or MinSize if specified.
void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); }
void push_back(const T &Elt) {
if (LLVM_UNLIKELY(this->size() >= this->capacity()))
this->grow();
memcpy(reinterpret_cast<void *>(this->end()), &Elt, sizeof(T));
this->set_size(this->size() + 1);
}
When grow is called in push_back() without a MinSize specified, this is
relying on the guarantee of space for at least one more element.
There is an edge case bug where the SmallVector is already at its maximum size
and push_back() calls grow() with default MinSize of zero. Grow is unable to
provide space for one more element, but push_back() assumes the additional
element it will be available. This can result in silent memory corruption, as
this->end() will be an invalid pointer and the program may continue executing.
An alternative to this fix would be to remove the default argument from
grow(), which would mean several changing grow() to grow(this->size()+1)
in several places.
No test case added because it would require allocating a large ammount.
Differential Revision: https://reviews.llvm.org/D77621
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
SmallVectorTemplateCommon wants to know the address of the first element
so it can detect whether it's in "small size" mode.
The old implementation split the small array, creating the storage for
the first element in SmallVectorTemplateCommon, and pulling the rest
into SmallVectorStorage where we know the size of the array. This
bloats SmallVector size 0 by the larger of sizeof(void*) and sizeof(T),
and we're not even using the storage.
The new implementation leaves the full small storage to
SmallVectorStorage. To calculate the offset of the first element in
SmallVectorTemplateCommon, we just need to know how far to jump, which
we can calculate out-of-band. One subtlety is that we need
SmallVectorStorage to be properly aligned even when the size is 0, to be
sure that (for large alignments) we actually have the padding and it's
well defined to do the pointer math.
llvm-svn: 337820
I'm optimistically reverting commit r337511, effectively reapplying
r337504 *without* changes.
The failing bots that had `SmallVector` in the backtrace recovered after
the unrelated commit r337508. The backtraces looked bogus anyway, with
`SmallVector::size()` calling (e.g.) `ConstantArray::get()`.
Here's the original commit message:
ADT: Shrink size of SmallVector by 8B on 64-bit platforms
Represent size and capacity directly as unsigned and calculate
`end()` using `begin() + size()`.
This limits the maximum size/capacity of a vector to UINT32_MAX.
https://reviews.llvm.org/D48518
llvm-svn: 337514
Representing size and capacity directly as unsigned and calculate
`end()` using `begin() + size()`.
This limits the maximum size/capacity of a vector to UINT32_MAX.
https://reviews.llvm.org/D48518
llvm-svn: 337504
This is a recommit of r333506, which was reverted in r333518.
The original commit message is below.
In r325551 many calls of malloc/calloc/realloc were replaces with calls of
their safe counterparts defined in the namespace llvm. There functions
generate crash if memory cannot be allocated, such behavior facilitates
handling of out of memory errors on Windows.
If the result of *alloc function were checked for success, the function was
not replaced with the safe variant. In these cases the calling function made
the error handling, like:
T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
if (NewElts == nullptr)
report_bad_alloc_error("Allocation of SmallVector element failed.");
Actually knowledge about the function where OOM occurred is useless. Moreover
having a single entry point for OOM handling is convenient for investigation
of memory problems. This change removes custom OOM errors handling and
replaces them with calls to functions `llvm::safe_*alloc`.
Declarations of `safe_*alloc` are moved to a separate include file, to avoid
cyclic dependency in SmallVector.h
Differential Revision: https://reviews.llvm.org/D47440
llvm-svn: 334344
This is a recommit of r333390, which was reverted in r333395, because it
caused cyclic dependency when building shared library `LLVMDemangle.so`.
In this commit `ItaniumDemangler.cpp` was not changed.
The original commit message is below.
In r325551 many calls of malloc/calloc/realloc were replaces with calls of
their safe counterparts defined in the namespace llvm. There functions
generate crash if memory cannot be allocated, such behavior facilitates
handling of out of memory errors on Windows.
If the result of *alloc function were checked for success, the function was
not replaced with the safe variant. In these cases the calling function made
the error handling, like:
T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
if (NewElts == nullptr)
report_bad_alloc_error("Allocation of SmallVector element failed.");
Actually knowledge about the function where OOM occurred is useless. Moreover
having a single entry point for OOM handling is convenient for investigation
of memory problems. This change removes custom OOM errors handling and
replaces them with calls to functions `llvm::safe_*alloc`.
Declarations of `safe_*alloc` are moved to a separate include file, to avoid
cyclic dependency in SmallVector.h
Differential Revision: https://reviews.llvm.org/D47440
llvm-svn: 333506
In r325551 many calls of malloc/calloc/realloc were replaces with calls of
their safe counterparts defined in the namespace llvm. There functions
generate crash if memory cannot be allocated, such behavior facilitates
handling of out of memory errors on Windows.
If the result of *alloc function were checked for success, the function was
not replaced with the safe variant. In these cases the calling function made
the error handling, like:
T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
if (NewElts == nullptr)
report_bad_alloc_error("Allocation of SmallVector element failed.");
Actually knowledge about the function where OOM occurred is useless. Moreover
having a single entry point for OOM handling is convenient for investigation
of memory problems. This change removes custom OOM errors handling and
replaces them with calls to functions `llvm::safe_*alloc`.
Declarations of `safe_*alloc` are moved to a separate include file, to avoid
cyclic dependency in SmallVector.h
Differential Revision: https://reviews.llvm.org/D47440
llvm-svn: 333390
As a follow up of the bad alloc handler patch, this patch introduces nullptr checks on pointers returned from the
malloc/realloc/calloc functions. In addition some memory size assignments are moved behind the allocation
of the corresponding memory to fulfill exception safe memory management (RAII).
patch by Klaus Kretzschmar
Differential Revision: https://reviews.llvm.org/D35414
llvm-svn: 308576
Summary:
If malloc/realloc fails then the SmallVector becomes unusable since begin() and
end() will return NULL. This is unlikely to occur but was the cause of recent
bugpoint test failures on my machine.
It is not clear whether not checking for malloc/realloc failure is a deliberate
decision and adding checks has the potential to impact compiler performance.
Therefore, this patch only adds the check to builds with assertions enabled for
the moment.
Reviewers: bkramer
Reviewed By: bkramer
Subscribers: bkramer, llvm-commits
Differential Revision: http://reviews.llvm.org/D9520
llvm-svn: 239392
Benjamin Kramer