Allow layout aliasing for desktop vertex inputs.

Test/430.vert

@@ -41,4 +41,7 @@ layout(location = 10) out S cs[2];     // 10 through 10 + 2 * 22 - 1 = 53
 layout(location = 54) out float cf;
 layout(location = 53) out float cg; // ERROR, collision at 31
 
+layout(location = 10) in vec4 alias1;
+layout(location = 10) in vec4 alias2;  // okay for vertex input on desktop
+
 float gl_ClipDistance[17];  // ERROR, size too big
\ No newline at end of file

Test/baseResults/430.vert.out

@@ -12,7 +12,7 @@ ERROR: 0:28: '' : cannot use invariant qualifier on a function parameter
 ERROR: 0:30: '' : cannot use layout qualifiers on a function parameter 
 ERROR: 0:31: '' : cannot use auxiliary or interpolation qualifiers on a function parameter 
 ERROR: 0:42: 'location' : repeated use of location 53
-ERROR: 0:44: 'gl_ClipDistance array size' : must be less than gl_MaxClipDistances (8)
+ERROR: 0:47: 'gl_ClipDistance array size' : must be less than gl_MaxClipDistances (8)
 ERROR: 13 compilation errors.  No code generated.
 
 
@@ -45,6 +45,8 @@ ERROR: node is still EOpNull!
 0:?     'cs' (layout(location=10 ) smooth out 2-element array of structure{m,f})
 0:?     'cf' (layout(location=54 ) smooth out float)
 0:?     'cg' (layout(location=53 ) smooth out float)
+0:?     'alias1' (layout(location=10 ) in 4-component vector of float)
+0:?     'alias2' (layout(location=10 ) in 4-component vector of float)
 0:?     'gl_VertexID' (gl_VertexId int)
 0:?     'gl_InstanceID' (gl_InstanceId int)
 

Todo.txt

@@ -33,9 +33,8 @@ Link Validation
           - ...
       + exactly one main
       + ES 3.0: fragment outputs all have locations, if more than one
-      - ES 3.0: location aliasing/overlap (except desktop vertex shader inputs)
-      - Non ES: binding overlap
-      + location overlap
+      + location aliasing/overlap (except desktop vertex shader inputs)
+      - Non ES: binding overlap for atomic counters
       + Non ES: geometry shader input array sizes and input layout qualifier declaration
       + Non ES: read or write to both gl_ClipVertex and gl_ClipDistance
       + Non ES: write to only one of gl_FragColor, gl_FragData, or user-declared

glslang/Include/revision.h

@@ -9,5 +9,5 @@
 // source have to figure out how to create revision.h just to get a build
 // going.  However, if it is not updated, it can be a version behind.
 
-#define GLSLANG_REVISION "24396"
-#define GLSLANG_DATE     "2013/12/06 14:45:15"
+#define GLSLANG_REVISION "24397"
+#define GLSLANG_DATE     "2013/12/06 16:57:42"

glslang/MachineIndependent/ParseHelper.cpp

@@ -2694,8 +2694,6 @@ void TParseContext::layoutTypeCheck(TSourceLoc loc, const TSymbol& symbol)
         // an array of size N, all elements of the array from binding through binding + N  1 must be within this
         // range."
         //
-        // TODO: 4.2 binding limits: binding error checking against limits, arrays
-        //
         if (type.getBasicType() != EbtSampler && type.getBasicType() != EbtBlock)
             error(loc, "requires block, or sampler/image, or atomic-counter type", "binding", "");
             // TODO: 4.2 functionality: atomic counter: include in test above

glslang/MachineIndependent/linkValidate.cpp

@@ -476,12 +476,14 @@ int TIntermediate::addUsedLocation(const TQualifier& qualifier, const TType& typ
 
     TRange range = { qualifier.layoutSlotLocation, qualifier.layoutSlotLocation + size - 1 };
 
-    // check for collisions
-    for (size_t r = 0; r < usedLocations[set].size(); ++r) {
-        if (range.last  >= usedLocations[set][r].start &&
-            range.start <= usedLocations[set][r].last) {
-            // there is a collision; pick one
-            return std::max(range.start, usedLocations[set][r].start);
+    // check for collisions, except for vertex inputs on desktop
+    if (! (profile != EEsProfile && language == EShLangVertex && qualifier.isPipeInput())) {
+        for (size_t r = 0; r < usedLocations[set].size(); ++r) {
+            if (range.last  >= usedLocations[set][r].start &&
+                range.start <= usedLocations[set][r].last) {
+                // there is a collision; pick one
+                return std::max(range.start, usedLocations[set][r].start);
+            }
         }
     }