Make host device return nullptr for bad mallocs (huge, 0, etc)

Signed-off-by: James Brodman <[email protected]>

Author: jbrodman

sycl/include/CL/sycl/detail/aligned_allocator.hpp

@@ -56,7 +56,7 @@ template <typename T> class aligned_allocator {
 
     pointer Result = reinterpret_cast<pointer>(
         detail::OSUtil::alignedAlloc(MAlignment, NumBytes));
-    if (!Result)
+    if (!Result || NumBytes == 0)
       throw std::bad_alloc();
     return Result;
   }

sycl/source/detail/usm/usm_impl.cpp

@@ -71,17 +71,21 @@ void *alignedAlloc(size_t Alignment, size_t Size, const context &Ctxt,
                    const device &Dev, alloc Kind) {
   void *RetVal = nullptr;
   if (Ctxt.is_host()) {
-    if (!Alignment) {
-      // worst case default
-      Alignment = 128;
-    }
-
-    aligned_allocator<char> Alloc(Alignment);
-    try {
-      RetVal = Alloc.allocate(Size);
-    } catch (const std::bad_alloc &) {
-      // Conform with Specification behavior
+    if (Kind == alloc::unknown) {
       RetVal = nullptr;
+    } else {
+      if (!Alignment) {
+        // worst case default
+        Alignment = 128;
+      }
+
+      aligned_allocator<char> Alloc(Alignment);
+      try {
+        RetVal = Alloc.allocate(Size);
+      } catch (const std::bad_alloc &) {
+        // Conform with Specification behavior
+        RetVal = nullptr;
+      }
     }
   } else {
     std::shared_ptr<context_impl> CtxImpl = detail::getSyclObjImpl(Ctxt);