llvm-mirror/lib/Support/SmallVector.cpp
Daniel Sanders a2fe278290 [ADT] Assert that SmallVectorBase::grow_pod() successfully reallocates memory.
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
2015-06-09 09:47:46 +00:00

42 lines
1.5 KiB
C++

//===- llvm/ADT/SmallVector.cpp - 'Normally small' vectors ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SmallVector class.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
/// grow_pod - This is an implementation of the grow() method which only works
/// on POD-like datatypes and is out of line to reduce code duplication.
void SmallVectorBase::grow_pod(void *FirstEl, size_t MinSizeInBytes,
size_t TSize) {
size_t CurSizeBytes = size_in_bytes();
size_t NewCapacityInBytes = 2 * capacity_in_bytes() + TSize; // Always grow.
if (NewCapacityInBytes < MinSizeInBytes)
NewCapacityInBytes = MinSizeInBytes;
void *NewElts;
if (BeginX == FirstEl) {
NewElts = malloc(NewCapacityInBytes);
// Copy the elements over. No need to run dtors on PODs.
memcpy(NewElts, this->BeginX, CurSizeBytes);
} else {
// If this wasn't grown from the inline copy, grow the allocated space.
NewElts = realloc(this->BeginX, NewCapacityInBytes);
}
assert(NewElts && "Out of memory");
this->EndX = (char*)NewElts+CurSizeBytes;
this->BeginX = NewElts;
this->CapacityX = (char*)this->BeginX + NewCapacityInBytes;
}