Use uniform mechanism for OOM errors handling

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

include/llvm/ADT/SmallVector.h

@@ -18,6 +18,7 @@
 #include "llvm/Support/AlignOf.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Support/MemAlloc.h"
 #include "llvm/Support/type_traits.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
@@ -238,9 +239,7 @@ void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
   size_t NewCapacity = size_t(NextPowerOf2(CurCapacity+2));
   if (NewCapacity < MinSize)
     NewCapacity = MinSize;
-  T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
-  if (NewElts == nullptr)
-    report_bad_alloc_error("Allocation of SmallVector element failed.");
+  T *NewElts = static_cast<T*>(llvm::safe_malloc(NewCapacity*sizeof(T)));
 
   // Move the elements over.
   this->uninitialized_move(this->begin(), this->end(), NewElts);

include/llvm/ADT/StringMap.h

@@ -164,9 +164,7 @@ public:
 
     StringMapEntry *NewItem =
       static_cast<StringMapEntry*>(Allocator.Allocate(AllocSize,Alignment));
-
-    if (NewItem == nullptr)
-      report_bad_alloc_error("Allocation of StringMap entry failed.");
+    assert(NewItem && "Unhandled out-of-memory");
 
     // Construct the value.
     new (NewItem) StringMapEntry(KeyLength, std::forward<InitTy>(InitVals)...);

include/llvm/Support/Allocator.h

@@ -23,8 +23,9 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Compiler.h"
-#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/MemAlloc.h"
 #include <algorithm>
 #include <cassert>
 #include <cstddef>
@@ -95,11 +96,7 @@ public:
 
   LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size,
                                                 size_t /*Alignment*/) {
-    void* memPtr =  malloc(Size);
-    if (memPtr == nullptr) 
-      report_bad_alloc_error("Allocation in MallocAllocator failed.");
-
-    return memPtr;
+    return safe_malloc(Size);
   }
 
   // Pull in base class overloads.
@@ -439,34 +436,6 @@ public:
   T *Allocate(size_t num = 1) { return Allocator.Allocate<T>(num); }
 };
 
-/// \{
-/// Counterparts of allocation functions defined in namespace 'std', which crash
-/// on allocation failure instead of returning null pointer.
-
-LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_malloc(size_t Sz) {
-  void *Result = std::malloc(Sz);
-  if (Result == nullptr)
-    report_bad_alloc_error("Allocation failed.");
-  return Result;
-}
-
-LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_calloc(size_t Count,
-                                                        size_t Sz) {
-  void *Result = std::calloc(Count, Sz);
-  if (Result == nullptr)
-    report_bad_alloc_error("Allocation failed.");
-  return Result;
-}
-
-LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_realloc(void *Ptr, size_t Sz) {
-  void *Result = std::realloc(Ptr, Sz);
-  if (Result == nullptr)
-    report_bad_alloc_error("Allocation failed.");
-  return Result;
-}
-
-/// \}
-
 } // end namespace llvm
 
 template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold>

include/llvm/Support/MemAlloc.h

@@ -0,0 +1,49 @@
+//===- MemAlloc.h - Memory allocation functions -----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file defines counterparts of C library allocation functions defined in
+/// the namespace 'std'. The new allocation functions crash on allocation
+/// failure instead of returning null pointer.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_MEMALLOC_H
+#define LLVM_SUPPORT_MEMALLOC_H
+
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <cstdlib>
+
+namespace llvm {
+
+LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_malloc(size_t Sz) {
+  void *Result = std::malloc(Sz);
+  if (Result == nullptr)
+    report_bad_alloc_error("Allocation failed");
+  return Result;
+}
+
+LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_calloc(size_t Count,
+                                                        size_t Sz) {
+  void *Result = std::calloc(Count, Sz);
+  if (Result == nullptr)
+    report_bad_alloc_error("Allocation failed");
+  return Result;
+}
+
+LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_realloc(void *Ptr, size_t Sz) {
+  void *Result = std::realloc(Ptr, Sz);
+  if (Result == nullptr)
+    report_bad_alloc_error("Allocation failed");
+  return Result;
+}
+
+}
+#endif

lib/IR/DataLayout.cpp

@@ -596,10 +596,8 @@ const StructLayout *DataLayout::getStructLayout(StructType *Ty) const {
   // Otherwise, create the struct layout.  Because it is variable length, we
   // malloc it, then use placement new.
   int NumElts = Ty->getNumElements();
-  StructLayout *L =
-    (StructLayout *)malloc(sizeof(StructLayout)+(NumElts-1) * sizeof(uint64_t));
-  if (L == nullptr)
-    report_bad_alloc_error("Allocation of StructLayout elements failed.");
+  StructLayout *L = (StructLayout *)
+      safe_malloc(sizeof(StructLayout)+(NumElts-1) * sizeof(uint64_t));
 
   // Set SL before calling StructLayout's ctor.  The ctor could cause other
   // entries to be added to TheMap, invalidating our reference.

lib/Support/FoldingSet.cpp

@@ -214,11 +214,8 @@ static void **GetBucketFor(unsigned Hash, void **Buckets, unsigned NumBuckets) {
 
 /// AllocateBuckets - Allocated initialized bucket memory.
 static void **AllocateBuckets(unsigned NumBuckets) {
-  void **Buckets = static_cast<void**>(calloc(NumBuckets+1, sizeof(void*)));
-
-  if (Buckets == nullptr)
-    report_bad_alloc_error("Allocation of Buckets failed.");
-  
+  void **Buckets = static_cast<void**>(safe_calloc(NumBuckets + 1,
+                                                   sizeof(void*)));
   // Set the very last bucket to be a non-null "pointer".
   Buckets[NumBuckets] = reinterpret_cast<void*>(-1);
   return Buckets;

lib/Support/Mutex.cpp

@@ -47,10 +47,7 @@ MutexImpl::MutexImpl( bool recursive)
 {
   // Declare the pthread_mutex data structures
   pthread_mutex_t* mutex =
-    static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
-
-  if (mutex == nullptr)
-    report_bad_alloc_error("Mutex allocation failed");
+    static_cast<pthread_mutex_t*>(safe_malloc(sizeof(pthread_mutex_t)));
 
   pthread_mutexattr_t attr;
 

lib/Support/SmallPtrSet.cpp

@@ -32,9 +32,7 @@ void SmallPtrSetImplBase::shrink_and_clear() {
   NumNonEmpty = NumTombstones = 0;
 
   // Install the new array.  Clear all the buckets to empty.
-  CurArray = (const void**)malloc(sizeof(void*) * CurArraySize);
-  if (CurArray == nullptr)
-    report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
+  CurArray = (const void**)safe_malloc(sizeof(void*) * CurArraySize);
 
   memset(CurArray, -1, CurArraySize*sizeof(void*));
 }
@@ -100,9 +98,7 @@ void SmallPtrSetImplBase::Grow(unsigned NewSize) {
   bool WasSmall = isSmall();
 
   // Install the new array.  Clear all the buckets to empty.
-  const void **NewBuckets = (const void**) malloc(sizeof(void*) * NewSize);
-  if (NewBuckets == nullptr)
-    report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
+  const void **NewBuckets = (const void**) safe_malloc(sizeof(void*) * NewSize);
 
   // Reset member only if memory was allocated successfully
   CurArray = NewBuckets;
@@ -132,9 +128,7 @@ SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
     CurArray = SmallArray;
   // Otherwise, allocate new heap space (unless we were the same size)
   } else {
-    CurArray = (const void**)malloc(sizeof(void*) * that.CurArraySize);
-    if (CurArray == nullptr)
-      report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
+    CurArray = (const void**)safe_malloc(sizeof(void*) * that.CurArraySize);
   }
 
   // Copy over the that array.
@@ -163,16 +157,12 @@ void SmallPtrSetImplBase::CopyFrom(const SmallPtrSetImplBase &RHS) {
   // Otherwise, allocate new heap space (unless we were the same size)
   } else if (CurArraySize != RHS.CurArraySize) {
     if (isSmall())
-      CurArray = (const void**)malloc(sizeof(void*) * RHS.CurArraySize);
+      CurArray = (const void**)safe_malloc(sizeof(void*) * RHS.CurArraySize);
     else {
-      const void **T = (const void**)realloc(CurArray,
+      const void **T = (const void**)safe_realloc(CurArray,
                                              sizeof(void*) * RHS.CurArraySize);
-      if (!T)
-        free(CurArray);
       CurArray = T;
     }
-    if (CurArray == nullptr)
-      report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
   }
 
   CopyHelper(RHS);

lib/Support/SmallVector.cpp

@@ -25,17 +25,13 @@ void SmallVectorBase::grow_pod(void *FirstEl, size_t MinSizeInBytes,
 
   void *NewElts;
   if (BeginX == FirstEl) {
-    NewElts = malloc(NewCapacityInBytes);
-    if (NewElts == nullptr)
-      report_bad_alloc_error("Allocation of SmallVector element failed.");
+    NewElts = safe_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);
-    if (NewElts == nullptr)
-      report_bad_alloc_error("Reallocation of SmallVector element failed.");
+    NewElts = safe_realloc(this->BeginX, NewCapacityInBytes);
   }
 
   this->EndX = (char*)NewElts+CurSizeBytes;

lib/Support/StringMap.cpp

@@ -59,10 +59,8 @@ void StringMapImpl::init(unsigned InitSize) {
   NumTombstones = 0;
 
   TheTable = static_cast<StringMapEntryBase **>(
-      std::calloc(NewNumBuckets+1,
+      safe_calloc(NewNumBuckets+1,
                   sizeof(StringMapEntryBase **) + sizeof(unsigned)));
-  if (TheTable == nullptr)
-    report_bad_alloc_error("Allocation of StringMap table failed.");
 
   // Set the member only if TheTable was successfully allocated
   NumBuckets = NewNumBuckets;
@@ -220,9 +218,7 @@ unsigned StringMapImpl::RehashTable(unsigned BucketNo) {
   // Allocate one extra bucket which will always be non-empty.  This allows the
   // iterators to stop at end.
   auto NewTableArray = static_cast<StringMapEntryBase **>(
-      std::calloc(NewSize+1, sizeof(StringMapEntryBase *) + sizeof(unsigned)));
-  if (NewTableArray == nullptr)
-    report_bad_alloc_error("Allocation of StringMap hash table failed.");
+      safe_calloc(NewSize+1, sizeof(StringMapEntryBase *) + sizeof(unsigned)));
 
   unsigned *NewHashArray = (unsigned *)(NewTableArray + NewSize + 1);
   NewTableArray[NewSize] = (StringMapEntryBase*)2;