From 1db55d6a827cc2625a48a494e426e64f0b36ac0e Mon Sep 17 00:00:00 2001
From: Star Zeng <star.zeng@intel.com>
Date: Mon, 17 Nov 2014 01:53:41 +0000
Subject: [PATCH] MdePkg Base.h: Fix EBC build failure and add comments for
 RETURN_ADDRESS macro.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16395 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Include/Base.h | 44 +++++++++++++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index 5934b0f998..def5aa6184 100644
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -1016,24 +1016,44 @@ typedef UINTN RETURN_STATUS;
 #define SIGNATURE_64(A, B, C, D, E, F, G, H) \
     (SIGNATURE_32 (A, B, C, D) | ((UINT64) (SIGNATURE_32 (E, F, G, H)) << 32))
 
-#if defined(_MSC_EXTENSIONS)
-  //
-  // Intrinsic function provides the address of the instruction in the calling
-  // function that will be executed after control returns to the caller.
-  //
+#if defined(_MSC_EXTENSIONS) && !defined (MDE_CPU_EBC)
   #pragma intrinsic(_ReturnAddress)
+  /**
+    Get the return address of the calling funcation.
+
+    Based on intrinsic function _ReturnAddress that provides the address of
+    the instruction in the calling function that will be executed after
+    control returns to the caller.
+
+    @param L    Return Level.
+
+    @return The return address of the calling funcation or 0 if L != 0.
+
+  **/
   #define RETURN_ADDRESS(L)     ((L == 0) ? _ReturnAddress() : (VOID *) 0)
 #elif defined(__GNUC__)
-  //
-  // Built-in Function returns the return address of the current function,
-  // or of one of its callers.
-  //
   void * __builtin_return_address (unsigned int level);
+  /**
+    Get the return address of the calling funcation.
+
+    Based on built-in Function __builtin_return_address that returns
+    the return address of the current function, or of one of its callers.
+
+    @param L    Return Level.
+
+    @return The return address of the calling funcation.
+
+  **/
   #define RETURN_ADDRESS(L)     __builtin_return_address (L)
 #else
-  //
-  // Compilers don't support this feature.
-  //
+  /**
+    Get the return address of the calling funcation.
+
+    @param L    Return Level.
+
+    @return 0 as compilers don't support this feature.
+
+  **/
   #define RETURN_ADDRESS(L)     ((VOID *) 0)
 #endif