Support, IR, ADT: Check nullptr after allocation with malloc/realloc or calloc

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

llvm/lib/Support/SmallPtrSet.cpp

@@ -15,6 +15,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdlib>
@@ -32,7 +33,9 @@ void SmallPtrSetImplBase::shrink_and_clear() {
 
   // Install the new array.  Clear all the buckets to empty.
   CurArray = (const void**)malloc(sizeof(void*) * CurArraySize);
-  assert(CurArray && "Failed to allocate memory?");
+  if (CurArray == nullptr)
+    report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
+
   memset(CurArray, -1, CurArraySize*sizeof(void*));
 }
 
@@ -96,8 +99,12 @@ void SmallPtrSetImplBase::Grow(unsigned NewSize) {
   bool WasSmall = isSmall();
 
   // Install the new array.  Clear all the buckets to empty.
-  CurArray = (const void**)malloc(sizeof(void*) * NewSize);
-  assert(CurArray && "Failed to allocate memory?");
+  const void **NewBuckets = (const void**) malloc(sizeof(void*) * NewSize);
+  if (NewBuckets == nullptr)
+    report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
+
+  // Reset member only if memory was allocated successfully
+  CurArray = NewBuckets;
   CurArraySize = NewSize;
   memset(CurArray, -1, NewSize*sizeof(void*));
 
@@ -125,7 +132,8 @@ SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
   // Otherwise, allocate new heap space (unless we were the same size)
   } else {
     CurArray = (const void**)malloc(sizeof(void*) * that.CurArraySize);
-    assert(CurArray && "Failed to allocate memory?");
+    if (CurArray == nullptr)
+      report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
   }
 
   // Copy over the that array.
@@ -162,7 +170,8 @@ void SmallPtrSetImplBase::CopyFrom(const SmallPtrSetImplBase &RHS) {
         free(CurArray);
       CurArray = T;
     }
-    assert(CurArray && "Failed to allocate memory?");
+    if (CurArray == nullptr)
+      report_bad_alloc_error("Allocation of SmallPtrSet bucket array failed.");
   }
 
   CopyHelper(RHS);