[HIP CLR] Make hipMemPtrGetInfo consistent with malloc and hipMalloc (#1005)

hipMemPtrGetInfo was returning the error hipErrorInvalidValue if it
was called on a nullptr.  However, this does not match the malloc
convention where a nullptr has size zero;  for example,
malloc_usable_size() returns zero if called on a nullptr.

This commit changes hipMemPtrGetInfo to set the size to zero and
return hipSuccess when called with a nullptr.  (This also fits with
hipMalloc and hipFree usage, since hipMalloc of size zero results in a
nullptr, and hipFree of a nullptr is successful.)

projects/clr/hipamd/src/hip_memory.cpp

@@ -1,4 +1,4 @@
-/* Copyright (c) 2015 - 2024 Advanced Micro Devices, Inc.
+/* Copyright (c) 2015 - 2025 Advanced Micro Devices, Inc.
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
@@ -829,6 +829,11 @@ hipError_t hipMemcpyWithStream(void* dst, const void* src, size_t sizeBytes, hip
 hipError_t hipMemPtrGetInfo(void* ptr, size_t* size) {
   HIP_INIT_API(hipMemPtrGetInfo, ptr, size);
 
+  if (ptr == nullptr) {
+    *size = 0;
+    HIP_RETURN(hipSuccess);
+  }
+
   size_t offset = 0;
   amd::Memory* svmMem = getMemoryObject(ptr, offset);
 

projects/hip-tests/catch/unit/memory/hipMemPtrGetInfo.cc

@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2021 Advanced Micro Devices, Inc. All rights reserved.
+Copyright (c) 2021 - 2025 Advanced Micro Devices, Inc. All rights reserved.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -56,3 +56,17 @@ TEST_CASE("Unit_hipMemPtrGetInfo_Basic") {
   HIP_CHECK(hipFree(fPtr));
   HIP_CHECK(hipFree(sPtr));
 }
+
+/*
+This testcase verifies the scenario of
+hipMemPtrGetInfo API being called on a zero-sized allocation.
+*/
+TEST_CASE("Unit_hipMemPtrGetInfo_SizeZeroAllocation") {
+  int* iPtr;
+  size_t sSetSize = 0, sGetSize;
+  HIP_CHECK(hipMalloc(&iPtr, sSetSize));
+  HIP_CHECK(hipMemPtrGetInfo(iPtr, &sGetSize));
+  REQUIRE(sGetSize == sSetSize);
+
+  HIP_CHECK(hipFree(iPtr));
+}