Re-sync with internal repository (#772)

Co-authored-by: Facebook Community Bot <6422482+facebook-github-bot@users.noreply.github.com>

external/llvh/include/llvh/ADT/SmallVector.h

@@ -238,12 +238,16 @@ class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
 // Define this out-of-line to dissuade the C++ compiler from inlining it.
 template <typename T, bool isPodLike>
 void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
-  if (MinSize > UINT32_MAX)
-    report_bad_alloc_error("SmallVector capacity overflow during allocation");
-
   // Always grow, even from zero.
-  size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + 2));
-  NewCapacity = std::min(std::max(NewCapacity, MinSize), size_t(UINT32_MAX));
+  constexpr size_t MinGrowth = 2;
+  size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + MinGrowth));
+  NewCapacity = static_cast<unsigned>(std::max(NewCapacity, MinSize));
+  // Ensure that NewCapacity did not overflow an unsigned int,
+  // and that the capacity in bytes will not overflow a size_t.
+  if (NewCapacity <= this->capacity() ||
+      NewCapacity < MinSize ||
+      NewCapacity > size_t(-1) / sizeof(T))
+    report_bad_alloc_error("SmallVector capacity overflow during allocation");
   T *NewElts = static_cast<T*>(llvh::safe_malloc(NewCapacity*sizeof(T)));
 
   // Move the elements over.

external/llvh/lib/Support/SmallVector.cpp

@@ -42,13 +42,16 @@ static_assert(sizeof(SmallVector<void *, 1>) ==
 /// on POD-like datatypes and is out of line to reduce code duplication.
 void SmallVectorBase::grow_pod(void *FirstEl, size_t MinCapacity,
                                size_t TSize) {
-  // Ensure we can fit the new capacity in 32 bits.
-  if (MinCapacity > UINT32_MAX)
-    report_bad_alloc_error("SmallVector capacity overflow during allocation");
+  constexpr size_t MinGrowth = 1;
+  size_t NewCapacity = 2 * capacity() + MinGrowth; // Always grow.
+  NewCapacity = static_cast<unsigned>(std::max(NewCapacity, MinCapacity));
 
-  size_t NewCapacity = 2 * capacity() + 1; // Always grow.
-  NewCapacity =
-      std::min(std::max(NewCapacity, MinCapacity), size_t(UINT32_MAX));
+  // Ensure that NewCapacity did not overflow an unsigned int,
+  // and that the capacity in bytes will not overflow a size_t.
+  if (NewCapacity <= this->capacity() ||
+      NewCapacity < MinCapacity ||
+      NewCapacity > size_t(-1) / TSize)
+    report_bad_alloc_error("SmallVector capacity overflow during allocation");
 
   void *NewElts;
   if (BeginX == FirstEl) {

external/llvh/patches/SmallVector.patch

@@ -0,0 +1,51 @@
+diff --git a/xplat/hermes/external/llvh/include/llvh/ADT/SmallVector.h b/xplat/hermes/external/llvh/include/llvh/ADT/SmallVector.h
+--- a/xplat/hermes/external/llvh/include/llvh/ADT/SmallVector.h
++++ b/xplat/hermes/external/llvh/include/llvh/ADT/SmallVector.h
+@@ -238,12 +238,16 @@
+ // Define this out-of-line to dissuade the C++ compiler from inlining it.
+ template <typename T, bool isPodLike>
+ void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
+-  if (MinSize > UINT32_MAX)
+-    report_bad_alloc_error("SmallVector capacity overflow during allocation");
+-
+   // Always grow, even from zero.
+-  size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + 2));
+-  NewCapacity = std::min(std::max(NewCapacity, MinSize), size_t(UINT32_MAX));
++  constexpr size_t MinGrowth = 2;
++  size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + MinGrowth));
++  NewCapacity = static_cast<unsigned>(std::max(NewCapacity, MinSize));
++  // Ensure that NewCapacity did not overflow an unsigned int,
++  // and that the capacity in bytes will not overflow a size_t.
++  if (NewCapacity <= this->capacity() ||
++      NewCapacity < MinSize ||
++      NewCapacity > size_t(-1) / sizeof(T))
++    report_bad_alloc_error("SmallVector capacity overflow during allocation");
+   T *NewElts = static_cast<T*>(llvh::safe_malloc(NewCapacity*sizeof(T)));
+
+   // Move the elements over.
+diff --git a/xplat/hermes/external/llvh/lib/Support/SmallVector.cpp b/xplat/hermes/external/llvh/lib/Support/SmallVector.cpp
+--- a/xplat/hermes/external/llvh/lib/Support/SmallVector.cpp
++++ b/xplat/hermes/external/llvh/lib/Support/SmallVector.cpp
+@@ -42,13 +42,16 @@
+ /// on POD-like datatypes and is out of line to reduce code duplication.
+ void SmallVectorBase::grow_pod(void *FirstEl, size_t MinCapacity,
+                                size_t TSize) {
+-  // Ensure we can fit the new capacity in 32 bits.
+-  if (MinCapacity > UINT32_MAX)
+-    report_bad_alloc_error("SmallVector capacity overflow during allocation");
++  constexpr size_t MinGrowth = 1;
++  size_t NewCapacity = 2 * capacity() + MinGrowth; // Always grow.
++  NewCapacity = static_cast<unsigned>(std::max(NewCapacity, MinCapacity));
+
+-  size_t NewCapacity = 2 * capacity() + 1; // Always grow.
+-  NewCapacity =
+-      std::min(std::max(NewCapacity, MinCapacity), size_t(UINT32_MAX));
++  // Ensure that NewCapacity did not overflow an unsigned int,
++  // and that the capacity in bytes will not overflow a size_t.
++  if (NewCapacity <= this->capacity() ||
++      NewCapacity < MinCapacity ||
++      NewCapacity > size_t(-1) / TSize)
++    report_bad_alloc_error("SmallVector capacity overflow during allocation");
+
+   void *NewElts;
+   if (BeginX == FirstEl) {