1 files changed, 58 insertions, 0 deletions
diff --git a/src/debug/daccess/request_common.h b/src/debug/daccess/request_common.h
new file mode 100644
index 0000000000..aef46b14ff
--- /dev/null
+++ b/src/debug/daccess/request_common.h
@@ -0,0 +1,58 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+// This file contains functions used by both request.cpp and request_svr.cpp
+// to communicate with the debuggee's GC.
+
+#ifndef _REQUEST_COMMON_H_
+#define _REQUEST_COMMON_H_
+
+// Indexes into an array of elements of type T, where the size of type
+// T is not (or may not be) known at compile-time. 
+// Returns a DPTR to the requested element (the element at the given index).
+template<typename T>
+DPTR(T) TableIndex(DPTR(T) base, size_t index, size_t t_size)
+{
+    TADDR base_addr = base.GetAddr();
+    TADDR element_addr = DacTAddrOffset(base_addr, index, t_size);
+    return __DPtr<T>(element_addr); 
+}
+
+// Dereferences a DPTR(T*), yielding a DPTR(T).
+template<typename T>
+DPTR(T) Dereference(DPTR(T*) ptr)
+{
+    TADDR ptr_base = (TADDR)*ptr;
+    return __DPtr<T>(ptr_base);
+}
+
+// Indexes into a given generation table, returning a DPTR to the
+// requested element (the element at the given index) of the table.
+inline DPTR(dac_generation)
+GenerationTableIndex(DPTR(dac_generation) base, size_t index)
+{
+    return TableIndex(base, index, g_gcDacGlobals->generation_size);
+}
+
+// Indexes into a heap's generation table, given the heap instance
+// and the desired index. Returns a DPTR to the requested element.
+inline DPTR(dac_generation)
+ServerGenerationTableIndex(DPTR(dac_gc_heap) heap, size_t index)
+{
+    TADDR base_addr = dac_cast<TADDR>(heap) + offsetof(dac_gc_heap, generation_table);
+    DPTR(dac_generation) base = __DPtr<dac_generation>(base_addr);
+    return TableIndex(base, index, g_gcDacGlobals->generation_size);
+}
+
+// Indexes into the global heap table, returning a DPTR to the requested
+// heap instance.
+inline DPTR(dac_gc_heap)
+HeapTableIndex(DPTR(dac_gc_heap**) heaps, size_t index)
+{
+    DPTR(dac_gc_heap*) heap_table = Dereference(heaps);
+    DPTR(dac_gc_heap*) ptr = TableIndex(heap_table, index, sizeof(dac_gc_heap*));
+    return Dereference(ptr);
+}
+
+#endif // _REQUEST_COMMON_H_