The first redeclarations of gl_FragCoord must appear before any

use of gl_FragCoord.

Test/baseResults/150.frag.out

@@ -2,7 +2,6 @@
 ERROR: 0:4: 'redeclaration' : cannot redeclare with different qualification: gl_FragCoord
 ERROR: 0:5: 'redeclaration' : cannot redeclare with different qualification: gl_FragCoord
 ERROR: 0:6: 'layout qualifier' : can only apply origin_upper_left and pixel_center_origin to gl_FragCoord 
-ERROR: 0:14: 'gl_FragCoord' : cannot redeclare after use 
 ERROR: 0:50: 'gl_PerFragment' : undeclared identifier 
 ERROR: 0:53: 'double' : Reserved word. 
 ERROR: 0:53: 'double' : not supported for this version or the enabled extensions 
@@ -19,7 +18,7 @@ ERROR: 0:154: 'assign' :  cannot convert from ' const float' to ' temp 2-compone
 ERROR: 0:155: 'textureQueryLOD' : no matching overloaded function found 
 ERROR: 0:155: 'assign' :  cannot convert from ' const float' to ' temp 2-component vector of float'
 ERROR: 0:183: 'mix' : required extension not requested: GL_EXT_shader_integer_mix
-ERROR: 18 compilation errors.  No code generated.
+ERROR: 17 compilation errors.  No code generated.
 
 
 Shader version: 150

Test/baseResults/gl_FragCoord.frag.out

@@ -0,0 +1,269 @@
+gl_FragCoord.frag
+Shader version: 150
+Requested GL_ARB_explicit_attrib_location
+gl_FragCoord pixel center is integer
+gl_FragCoord origin is upper left
+0:? Sequence
+0:9  Sequence
+0:9    move second child to first child ( temp float)
+0:9      'myGlobalVar' ( global float)
+0:9      direct index ( temp float)
+0:9        'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:9        Constant:
+0:9          0 (const int)
+0:16  Function Definition: main( ( global void)
+0:16    Function Parameters: 
+0:17    Sequence
+0:17      move second child to first child ( temp 4-component vector of float)
+0:17        'myColor' (layout( location=0) out 4-component vector of float)
+0:17        Constant:
+0:17          0.200000
+0:17          0.200000
+0:17          0.200000
+0:17          0.200000
+0:18      Test condition and select ( temp void)
+0:18        Condition
+0:18        Compare Greater Than or Equal ( temp bool)
+0:18          direct index ( temp float)
+0:18            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:18            Constant:
+0:18              1 (const int)
+0:18          Constant:
+0:18            10.000000
+0:18        true case
+0:19        Sequence
+0:19          move second child to first child ( temp float)
+0:19            direct index ( temp float)
+0:19              'myColor' (layout( location=0) out 4-component vector of float)
+0:19              Constant:
+0:19                2 (const int)
+0:19            Constant:
+0:19              0.800000
+0:21      Test condition and select ( temp void)
+0:21        Condition
+0:21        Compare Equal ( temp bool)
+0:21          direct index ( temp float)
+0:21            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:21            Constant:
+0:21              1 (const int)
+0:21          trunc ( global float)
+0:21            direct index ( temp float)
+0:21              'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:21              Constant:
+0:21                1 (const int)
+0:21        true case
+0:22        Sequence
+0:22          move second child to first child ( temp float)
+0:22            direct index ( temp float)
+0:22              'myColor' (layout( location=0) out 4-component vector of float)
+0:22              Constant:
+0:22                1 (const int)
+0:22            Constant:
+0:22              0.800000
+0:24      Test condition and select ( temp void)
+0:24        Condition
+0:24        Compare Equal ( temp bool)
+0:24          direct index ( temp float)
+0:24            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:24            Constant:
+0:24              0 (const int)
+0:24          trunc ( global float)
+0:24            direct index ( temp float)
+0:24              'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:24              Constant:
+0:24                0 (const int)
+0:24        true case
+0:25        Sequence
+0:25          move second child to first child ( temp float)
+0:25            direct index ( temp float)
+0:25              'myColor' (layout( location=0) out 4-component vector of float)
+0:25              Constant:
+0:25                0 (const int)
+0:25            Constant:
+0:25              0.800000
+0:28      Sequence
+0:28        move second child to first child ( temp 4-component vector of float)
+0:28          'diff' ( temp 4-component vector of float)
+0:28          subtract ( temp 4-component vector of float)
+0:28            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:28            'i' ( smooth in 4-component vector of float)
+0:29      Test condition and select ( temp void)
+0:29        Condition
+0:29        Compare Greater Than ( temp bool)
+0:29          Absolute value ( global float)
+0:29            direct index ( temp float)
+0:29              'diff' ( temp 4-component vector of float)
+0:29              Constant:
+0:29                2 (const int)
+0:29          Constant:
+0:29            0.001000
+0:29        true case
+0:29        move second child to first child ( temp float)
+0:29          direct index ( temp float)
+0:29            'myColor' (layout( location=0) out 4-component vector of float)
+0:29            Constant:
+0:29              2 (const int)
+0:29          Constant:
+0:29            0.500000
+0:30      Test condition and select ( temp void)
+0:30        Condition
+0:30        Compare Greater Than ( temp bool)
+0:30          Absolute value ( global float)
+0:30            direct index ( temp float)
+0:30              'diff' ( temp 4-component vector of float)
+0:30              Constant:
+0:30                3 (const int)
+0:30          Constant:
+0:30            0.001000
+0:30        true case
+0:30        move second child to first child ( temp float)
+0:30          direct index ( temp float)
+0:30            'myColor' (layout( location=0) out 4-component vector of float)
+0:30            Constant:
+0:30              3 (const int)
+0:30          Constant:
+0:30            0.500000
+0:?   Linker Objects
+0:?     'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:?     'myGlobalVar' ( global float)
+0:?     'i' ( smooth in 4-component vector of float)
+0:?     'myColor' (layout( location=0) out 4-component vector of float)
+0:?     'eps' ( const float)
+0:?       0.001000
+
+
+Linked fragment stage:
+
+
+Shader version: 150
+Requested GL_ARB_explicit_attrib_location
+gl_FragCoord pixel center is integer
+gl_FragCoord origin is upper left
+0:? Sequence
+0:9  Sequence
+0:9    move second child to first child ( temp float)
+0:9      'myGlobalVar' ( global float)
+0:9      direct index ( temp float)
+0:9        'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:9        Constant:
+0:9          0 (const int)
+0:16  Function Definition: main( ( global void)
+0:16    Function Parameters: 
+0:17    Sequence
+0:17      move second child to first child ( temp 4-component vector of float)
+0:17        'myColor' (layout( location=0) out 4-component vector of float)
+0:17        Constant:
+0:17          0.200000
+0:17          0.200000
+0:17          0.200000
+0:17          0.200000
+0:18      Test condition and select ( temp void)
+0:18        Condition
+0:18        Compare Greater Than or Equal ( temp bool)
+0:18          direct index ( temp float)
+0:18            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:18            Constant:
+0:18              1 (const int)
+0:18          Constant:
+0:18            10.000000
+0:18        true case
+0:19        Sequence
+0:19          move second child to first child ( temp float)
+0:19            direct index ( temp float)
+0:19              'myColor' (layout( location=0) out 4-component vector of float)
+0:19              Constant:
+0:19                2 (const int)
+0:19            Constant:
+0:19              0.800000
+0:21      Test condition and select ( temp void)
+0:21        Condition
+0:21        Compare Equal ( temp bool)
+0:21          direct index ( temp float)
+0:21            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:21            Constant:
+0:21              1 (const int)
+0:21          trunc ( global float)
+0:21            direct index ( temp float)
+0:21              'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:21              Constant:
+0:21                1 (const int)
+0:21        true case
+0:22        Sequence
+0:22          move second child to first child ( temp float)
+0:22            direct index ( temp float)
+0:22              'myColor' (layout( location=0) out 4-component vector of float)
+0:22              Constant:
+0:22                1 (const int)
+0:22            Constant:
+0:22              0.800000
+0:24      Test condition and select ( temp void)
+0:24        Condition
+0:24        Compare Equal ( temp bool)
+0:24          direct index ( temp float)
+0:24            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:24            Constant:
+0:24              0 (const int)
+0:24          trunc ( global float)
+0:24            direct index ( temp float)
+0:24              'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:24              Constant:
+0:24                0 (const int)
+0:24        true case
+0:25        Sequence
+0:25          move second child to first child ( temp float)
+0:25            direct index ( temp float)
+0:25              'myColor' (layout( location=0) out 4-component vector of float)
+0:25              Constant:
+0:25                0 (const int)
+0:25            Constant:
+0:25              0.800000
+0:28      Sequence
+0:28        move second child to first child ( temp 4-component vector of float)
+0:28          'diff' ( temp 4-component vector of float)
+0:28          subtract ( temp 4-component vector of float)
+0:28            'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:28            'i' ( smooth in 4-component vector of float)
+0:29      Test condition and select ( temp void)
+0:29        Condition
+0:29        Compare Greater Than ( temp bool)
+0:29          Absolute value ( global float)
+0:29            direct index ( temp float)
+0:29              'diff' ( temp 4-component vector of float)
+0:29              Constant:
+0:29                2 (const int)
+0:29          Constant:
+0:29            0.001000
+0:29        true case
+0:29        move second child to first child ( temp float)
+0:29          direct index ( temp float)
+0:29            'myColor' (layout( location=0) out 4-component vector of float)
+0:29            Constant:
+0:29              2 (const int)
+0:29          Constant:
+0:29            0.500000
+0:30      Test condition and select ( temp void)
+0:30        Condition
+0:30        Compare Greater Than ( temp bool)
+0:30          Absolute value ( global float)
+0:30            direct index ( temp float)
+0:30              'diff' ( temp 4-component vector of float)
+0:30              Constant:
+0:30                3 (const int)
+0:30          Constant:
+0:30            0.001000
+0:30        true case
+0:30        move second child to first child ( temp float)
+0:30          direct index ( temp float)
+0:30            'myColor' (layout( location=0) out 4-component vector of float)
+0:30            Constant:
+0:30              3 (const int)
+0:30          Constant:
+0:30            0.500000
+0:?   Linker Objects
+0:?     'gl_FragCoord' ( gl_FragCoord 4-component vector of float FragCoord)
+0:?     'myGlobalVar' ( global float)
+0:?     'i' ( smooth in 4-component vector of float)
+0:?     'myColor' (layout( location=0) out 4-component vector of float)
+0:?     'eps' ( const float)
+0:?       0.001000
+

Test/gl_FragCoord.frag

@@ -0,0 +1,31 @@
+#version 150 core
+#extension GL_ARB_explicit_attrib_location : enable
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+layout (origin_upper_left,pixel_center_integer) in vec4 gl_FragCoord;
+float myGlobalVar = gl_FragCoord.x;
+layout (origin_upper_left,pixel_center_integer) in vec4 gl_FragCoord;
+
+in vec4 i;
+layout (location = 0) out vec4 myColor;
+const float eps=0.001;
+
+void main() {
+    myColor = vec4(0.2);
+    if (gl_FragCoord.y >= 10) {
+        myColor.b = 0.8;
+    }
+    if (gl_FragCoord.y == trunc(gl_FragCoord.y)) {
+        myColor.g = 0.8;
+    }
+    if (gl_FragCoord.x == trunc(gl_FragCoord.x)) {
+        myColor.r = 0.8;
+    }
+
+    vec4 diff = gl_FragCoord - i;
+    if (abs(diff.z)>eps) myColor.b = 0.5;
+    if (abs(diff.w)>eps) myColor.a = 0.5;
+}

glslang/MachineIndependent/ParseHelper.cpp

@@ -4680,7 +4680,7 @@ TSymbol* TParseContext::redeclareBuiltinVariable(const TSourceLoc& loc, const TS
                 symbolQualifier.storage != qualifier.storage)
                 error(loc, "cannot change qualification of", "redeclaration", symbol->getName().c_str());
         } else if (identifier == "gl_FragCoord") {
-            if (intermediate.inIoAccessed("gl_FragCoord"))
+            if (!intermediate.getTexCoordRedeclared() && intermediate.inIoAccessed("gl_FragCoord"))
                 error(loc, "cannot redeclare after use", "gl_FragCoord", "");
             if (qualifier.nopersp != symbolQualifier.nopersp || qualifier.flat != symbolQualifier.flat ||
                 qualifier.isMemory() || qualifier.isAuxiliary())
@@ -4690,6 +4690,9 @@ TSymbol* TParseContext::redeclareBuiltinVariable(const TSourceLoc& loc, const TS
             if (! builtIn && (publicType.pixelCenterInteger != intermediate.getPixelCenterInteger() ||
                               publicType.originUpperLeft != intermediate.getOriginUpperLeft()))
                 error(loc, "cannot redeclare with different qualification:", "redeclaration", symbol->getName().c_str());
+
+
+            intermediate.setTexCoordRedeclared();
             if (publicType.pixelCenterInteger)
                 intermediate.setPixelCenterInteger();
             if (publicType.originUpperLeft)

glslang/MachineIndependent/localintermediate.h

@@ -309,7 +309,7 @@ public:
         useVulkanMemoryModel(false),
         invocations(TQualifier::layoutNotSet), vertices(TQualifier::layoutNotSet),
         inputPrimitive(ElgNone), outputPrimitive(ElgNone),
-        pixelCenterInteger(false), originUpperLeft(false),
+        pixelCenterInteger(false), originUpperLeft(false),texCoordBuiltinRedeclared(false),
         vertexSpacing(EvsNone), vertexOrder(EvoNone), interlockOrdering(EioNone), pointMode(false), earlyFragmentTests(false),
         postDepthCoverage(false), depthLayout(EldNone),
         hlslFunctionality1(false),
@@ -834,6 +834,8 @@ public:
     bool getOriginUpperLeft() const { return originUpperLeft; }
     void setPixelCenterInteger() { pixelCenterInteger = true; }
     bool getPixelCenterInteger() const { return pixelCenterInteger; }
+    void setTexCoordRedeclared() { texCoordBuiltinRedeclared = true; }
+    bool getTexCoordRedeclared() const { return texCoordBuiltinRedeclared; }
     void addBlendEquation(TBlendEquationShift b) { blendEquations |= (1 << b); }
     unsigned int getBlendEquations() const { return blendEquations; }
     bool setXfbBufferStride(int buffer, unsigned stride)
@@ -1122,6 +1124,7 @@ protected:
     TLayoutGeometry outputPrimitive;
     bool pixelCenterInteger;
     bool originUpperLeft;
+    bool texCoordBuiltinRedeclared;
     TVertexSpacing vertexSpacing;
     TVertexOrder vertexOrder;
     TInterlockOrdering interlockOrdering;
@@ -1182,6 +1185,7 @@ protected:
                                             // for callableData/callableDataIn
     // set of names of statically read/written I/O that might need extra checking
     std::set<TString> ioAccessed;
+
     // source code of shader, useful as part of debug information
     std::string sourceFile;
     std::string sourceText;

gtests/AST.FromFile.cpp

@@ -295,6 +295,7 @@ INSTANTIATE_TEST_SUITE_P(
         "EndStreamPrimitive.geom",
         "floatBitsToInt.vert",
         "coord_conventions.frag",
+        "gl_FragCoord.frag"
     })),
     FileNameAsCustomTestSuffix
 );