Add analysis utility to detect discontinuities.

src/build_angle.gyp

@@ -161,6 +161,8 @@
       ],
       'sources': [
         'compiler/CodeGenGLSL.cpp',
+        'compiler/DetectDiscontinuity.cpp',
+        'compiler/DetectDiscontinuity.h',
         'compiler/OutputESSL.cpp',
         'compiler/OutputESSL.h',        
         'compiler/OutputGLSLBase.cpp',

src/compiler/DetectDiscontinuity.cpp

+//
+// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Contains analysis utilities for dealing with HLSL's lack of support for
+// the use of intrinsic functions which (implicitly or explicitly) compute
+// gradients of functions with discontinuities. 
+//
+
+#include "compiler/DetectDiscontinuity.h"
+
+namespace sh
+{
+bool DetectDiscontinuity::traverse(TIntermNode *node)
+{
+    mDiscontinuity = false;
+    node->traverse(this);
+    return mDiscontinuity;
+}
+
+bool DetectDiscontinuity::visitBranch(Visit visit, TIntermBranch *node)
+{
+    switch (node->getFlowOp())
+    {
+      case EOpKill:
+        break;
+      case EOpBreak:
+      case EOpContinue:
+        mDiscontinuity = true;
+      case EOpReturn:
+        break;
+      default: UNREACHABLE();
+    }
+
+    return !mDiscontinuity;
+}
+}

src/compiler/DetectDiscontinuity.h

+//
+// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Contains analysis utilities for dealing with HLSL's lack of support for
+// the use of intrinsic functions which (implicitly or explicitly) compute
+// gradients of functions with discontinuities. 
+//
+
+#ifndef COMPILER_DETECTDISCONTINUITY_H_
+#define COMPILER_DETECTDISCONTINUITY_H_
+
+#include "compiler/intermediate.h"
+
+namespace sh
+{
+class DetectDiscontinuity : public TIntermTraverser
+{
+  public:
+    bool traverse(TIntermNode *node);
+
+  protected:
+    bool visitBranch(Visit visit, TIntermBranch *node);
+
+    bool mDiscontinuity;
+};
+
+bool containsDiscontinuity(TIntermNode *node)
+{
+    DetectDiscontinuity detectDiscontinuity;
+    return detectDiscontinuity.traverse(node);
+}
+}
+
+#endif   // COMPILER_DETECTDISCONTINUITY_H_

src/compiler/translator_hlsl.vcproj

@@ -51,9 +51,9 @@
 				RuntimeLibrary="1"
 				UsePrecompiledHeader="0"
 				WarningLevel="4"
-				DisableSpecificWarnings="4100;4127;4189;4239;4244;4245;4512;4702"
-				DebugInformationFormat="4"
 				WarnAsError="true"
+				DebugInformationFormat="4"
+				DisableSpecificWarnings="4100;4127;4189;4239;4244;4245;4512;4702"
 			/>
 			<Tool
 				Name="VCManagedResourceCompilerTool"
@@ -117,9 +117,9 @@
 				EnableFunctionLevelLinking="true"
 				UsePrecompiledHeader="0"
 				WarningLevel="4"
-				DisableSpecificWarnings="4100;4127;4189;4239;4244;4245;4512;4702"
-				DebugInformationFormat="3"
 				WarnAsError="true"
+				DebugInformationFormat="3"
+				DisableSpecificWarnings="4100;4127;4189;4239;4244;4245;4512;4702"
 			/>
 			<Tool
 				Name="VCManagedResourceCompilerTool"
@@ -295,6 +295,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\DetectDiscontinuity.cpp"
+				>
+			</File>
+			<File
 				RelativePath=".\OutputHLSL.cpp"
 				>
 			</File>
@@ -317,6 +321,10 @@
 			UniqueIdentifier="{93995380-89BD-4b04-88EB-625FBE52EBFB}"
 			>
 			<File
+				RelativePath=".\DetectDiscontinuity.h"
+				>
+			</File>
+			<File
 				RelativePath=".\OutputHLSL.h"
 				>
 			</File>