add code to clGetMemAllocInfoINTEL in USMChecking if it is NULL (#130)

It's possible that an application will never get an extension
function pointer for clGetMemAllocInfoINTEL, in which case there
will not be an entry in the dispatch table for it and it will be
NULL for USMChecking.  So, add checks for a NULL function pointer,
and attempt to get the extension function pointer if it it is
NULL.

Author: bashbaug

intercept/src/intercept.cpp

@@ -6071,14 +6071,66 @@ void CLIntercept::checkKernelArgUSMPointer(
 {
     std::lock_guard<std::mutex> lock(m_Mutex);
 
-    if( arg == NULL )
+    cl_int errorCode = CL_SUCCESS;
+
+    // If we don't have a function pointer for clGetMemAllocINFO, try to
+    // get one.  It's possible that the function pointer exists but
+    // the application hasn't queried for it yet, in which case it won't
+    // be installed into the dispatch table.
+    if( dispatch().clGetMemAllocInfoINTEL == NULL )
+    {
+        cl_program  program = NULL;
+        if( errorCode == CL_SUCCESS )
+        {
+            errorCode = dispatch().clGetKernelInfo(
+                kernel,
+                CL_KERNEL_PROGRAM,
+                sizeof(program),
+                &program,
+                NULL );
+        }
+
+        cl_uint         numDevices = 0;
+        cl_device_id*   deviceList = NULL;
+        if( errorCode == CL_SUCCESS )
+        {
+            errorCode = allocateAndGetProgramDeviceList(
+                program,
+                numDevices,
+                deviceList );
+        }
+
+        cl_platform_id  platform = NULL;
+        if( errorCode == CL_SUCCESS && numDevices > 0 )
+        {
+            errorCode = dispatch().clGetDeviceInfo(
+                deviceList[0],
+                CL_DEVICE_PLATFORM,
+                sizeof(platform),
+                &platform,
+                NULL );
+        }
+
+        if( errorCode == CL_SUCCESS )
+        {
+            getExtensionFunctionAddress(
+                platform,
+                "clGetMemAllocInfoINTEL" );
+        }
+
+        delete [] deviceList;
+    }
+
+    if( dispatch().clGetMemAllocInfoINTEL == NULL )
+    {
+        logf( "function pointer for clGetMemAllocInfoINTEL is NULL\n" );
+    }
+    else if( arg == NULL )
     {
         logf( "mem pointer %p is NULL\n", arg );
     }
     else
     {
-        cl_int errorCode = CL_SUCCESS;
-
         cl_context  context = NULL;
         if( errorCode == CL_SUCCESS )
         {
@@ -6090,10 +6142,11 @@ void CLIntercept::checkKernelArgUSMPointer(
                 NULL );
         }
 
-        cl_unified_shared_memory_type_intel memType = CL_MEM_TYPE_UNKNOWN_INTEL;
-        cl_device_id associatedDevice = NULL;
         if( errorCode == CL_SUCCESS )
         {
+            cl_unified_shared_memory_type_intel memType = CL_MEM_TYPE_UNKNOWN_INTEL;
+            cl_device_id associatedDevice = NULL;
+
             dispatch().clGetMemAllocInfoINTEL(
                 context,
                 arg,
@@ -6135,7 +6188,7 @@ void CLIntercept::checkKernelArgUSMPointer(
                 else
                 {
                     CLI_ASSERT( 0 );
-                    logf( "mem pointer %p is a DEVICE pointer but has no associated device?\n",
+                    logf( "mem pointer %p is a DEVICE pointer without an associated device???\n",
                         arg );
                 }
             }
@@ -6167,7 +6220,7 @@ void CLIntercept::checkKernelArgUSMPointer(
             else if( memType == CL_MEM_TYPE_UNKNOWN_INTEL )
             {
                 // This could be a system shared USM pointer, or this could be an error.
-                // Check the devices associatd with this kernel to see if any support
+                // Check the devices associated with this kernel to see if any support
                 // system shared USM allocations.
                 cl_program  program = NULL;
                 if( errorCode == CL_SUCCESS )