Semantics: Geometry stage can support max_vertices = 0.

To do this, more generally use a named -1 as a not set value.

glslang/Include/Types.h

@@ -327,6 +327,8 @@ enum TBlendEquationShift {
 
 class TQualifier {
 public:
+    static const int layoutNotSet = -1;
+
     void clear()
     {
         precision = EpqNone;
@@ -489,8 +491,8 @@ public:
     {
         layoutMatrix = ElmNone;
         layoutPacking = ElpNone;
-        layoutOffset = -1;
-        layoutAlign = -1;
+        layoutOffset = layoutNotSet;
+        layoutAlign = layoutNotSet;
 
         layoutLocation = layoutLocationEnd;
         layoutComponent = layoutComponentEnd;
@@ -567,11 +569,11 @@ public:
     }
     bool hasOffset() const
     {
-        return layoutOffset != -1;
+        return layoutOffset != layoutNotSet;
     }
     bool hasAlign() const
     {
-        return layoutAlign != -1;
+        return layoutAlign != layoutNotSet;
     }
     bool hasAnyLocation() const
     {
@@ -789,7 +791,7 @@ struct TShaderQualifiers {
         originUpperLeft = false;
         pixelCenterInteger = false;
         invocations = 0;        // 0 means no declaration
-        vertices = 0;
+        vertices = TQualifier::layoutNotSet;
         spacing = EvsNone;
         order = EvoNone;
         pointMode = false;
@@ -813,7 +815,7 @@ struct TShaderQualifiers {
             originUpperLeft = src.originUpperLeft;
         if (src.invocations != 0)
             invocations = src.invocations;
-        if (src.vertices != 0)
+        if (src.vertices != TQualifier::layoutNotSet)
             vertices = src.vertices;
         if (src.spacing != EvsNone)
             spacing = src.spacing;

glslang/Include/revision.h

@@ -2,5 +2,5 @@
 // For the version, it uses the latest git tag followed by the number of commits.
 // For the date, it uses the current date (when then script is run).
 
-#define GLSLANG_REVISION "SPIRV99.839"
+#define GLSLANG_REVISION "SPIRV99.841"
 #define GLSLANG_DATE "11-Dec-2015"

glslang/MachineIndependent/ParseHelper.cpp

@@ -662,7 +662,7 @@ void TParseContext::handleIoResizeArrayAccess(const TSourceLoc& /*loc*/, TInterm
     // fix array size, if it can be fixed and needs to be fixed (will allow variable indexing)
     if (symbolNode->getType().isImplicitlySizedArray()) {
         int newSize = getIoArrayImplicitSize();
-        if (newSize)
+        if (newSize > 0)
             symbolNode->getWritableType().changeOuterArraySize(newSize);
     }
 }
@@ -703,7 +703,7 @@ int TParseContext::getIoArrayImplicitSize() const
     if (language == EShLangGeometry)
         return TQualifier::mapGeometryToSize(intermediate.getInputPrimitive());
     else if (language == EShLangTessControl)
-        return intermediate.getVertices();
+        return intermediate.getVertices() != TQualifier::layoutNotSet ? intermediate.getVertices() : 0;
     else
         return 0;
 }
@@ -3875,7 +3875,10 @@ void TParseContext::setLayoutQualifier(const TSourceLoc& loc, TPublicType& publi
 
     case EShLangTessControl:
         if (id == "vertices") {
-            publicType.shaderQualifiers.vertices = value;
+            if (value == 0)
+                error(loc, "must be greater than 0", "vertices", "");
+            else
+                publicType.shaderQualifiers.vertices = value;
             return;
         }
         break;
@@ -4275,7 +4278,7 @@ void TParseContext::checkNoShaderLayouts(const TSourceLoc& loc, const TShaderQua
         error(loc, message, TQualifier::getGeometryString(shaderQualifiers.geometry), "");
     if (shaderQualifiers.invocations > 0)
         error(loc, message, "invocations", "");
-    if (shaderQualifiers.vertices > 0) {
+    if (shaderQualifiers.vertices != TQualifier::layoutNotSet) {
         if (language == EShLangGeometry)
             error(loc, message, "max_vertices", "");
         else if (language == EShLangTessControl)
@@ -5438,7 +5441,7 @@ void TParseContext::invariantCheck(const TSourceLoc& loc, const TQualifier& qual
 //
 void TParseContext::updateStandaloneQualifierDefaults(const TSourceLoc& loc, const TPublicType& publicType)
 {
-    if (publicType.shaderQualifiers.vertices) {
+    if (publicType.shaderQualifiers.vertices != TQualifier::layoutNotSet) {
         assert(language == EShLangTessControl || language == EShLangGeometry);
         const char* id = (language == EShLangTessControl) ? "vertices" : "max_vertices";
 

glslang/MachineIndependent/linkValidate.cpp

@@ -100,7 +100,7 @@ void TIntermediate::merge(TInfoSink& infoSink, TIntermediate& unit)
     else if (outputPrimitive != unit.outputPrimitive)
         error(infoSink, "Contradictory output layout primitives");
     
-    if (vertices == 0)
+    if (vertices == TQualifier::layoutNotSet)
         vertices = unit.vertices;
     else if (vertices != unit.vertices) {
         if (language == EShLangGeometry)
@@ -409,7 +409,7 @@ void TIntermediate::finalCheck(TInfoSink& infoSink)
     case EShLangVertex:
         break;
     case EShLangTessControl:
-        if (vertices == 0)
+        if (vertices == TQualifier::layoutNotSet)
             error(infoSink, "At least one shader must specify an output layout(vertices=...)");
         break;
     case EShLangTessEvaluation:
@@ -425,7 +425,7 @@ void TIntermediate::finalCheck(TInfoSink& infoSink)
             error(infoSink, "At least one shader must specify an input layout primitive");
         if (outputPrimitive == ElgNone)
             error(infoSink, "At least one shader must specify an output layout primitive");
-        if (vertices == 0)
+        if (vertices == TQualifier::layoutNotSet)
             error(infoSink, "At least one shader must specify a layout(max_vertices = value)");
         break;
     case EShLangFragment:

glslang/MachineIndependent/localintermediate.h

@@ -126,7 +126,7 @@ class TIntermediate {
 public:
     explicit TIntermediate(EShLanguage l, int v = 0, EProfile p = ENoProfile) : language(l), treeRoot(0), profile(p), version(v), spv(0),
         numMains(0), numErrors(0), recursive(false),
-        invocations(0), vertices(0), inputPrimitive(ElgNone), outputPrimitive(ElgNone), pixelCenterInteger(false), originUpperLeft(false),
+        invocations(0), vertices(TQualifier::layoutNotSet), inputPrimitive(ElgNone), outputPrimitive(ElgNone), pixelCenterInteger(false), originUpperLeft(false),
         vertexSpacing(EvsNone), vertexOrder(EvoNone), pointMode(false), earlyFragmentTests(false), depthLayout(EldNone), depthReplacing(false), blendEquations(0), xfbMode(false)
     {
         localSize[0] = 1;
@@ -212,7 +212,7 @@ public:
     int getInvocations() const { return invocations; }
     bool setVertices(int m)
     {
-        if (vertices > 0)
+        if (vertices != TQualifier::layoutNotSet)
             return vertices == m;
         vertices = m;
         return true;