1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/Support/SmallVector.cpp b/llvm/lib/Support/SmallVector.cpp
index 36f0a81..9ece0c5 100644
--- a/llvm/lib/Support/SmallVector.cpp
+++ b/llvm/lib/Support/SmallVector.cpp
@@ -39,12 +39,19 @@ static_assert(sizeof(SmallVector<void *, 1>) ==
 
 /// 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.
+/// This function will report a fatal error if it cannot increase capacity.
 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");
 
+  // Ensure we can meet the guarantee of space for at least one more element.
+  // The above check alone will not catch the case where grow is called with a
+  // default MinCapacity of 0, but the current capacity cannot be increased.
+  if (capacity() == size_t(UINT32_MAX))
+    report_bad_alloc_error("SmallVector capacity unable to grow");
+
   size_t NewCapacity = 2 * capacity() + 1; // Always grow.
   NewCapacity =
       std::min(std::max(NewCapacity, MinCapacity), size_t(UINT32_MAX));