Fix precision tracking of constructor return values

src/compiler/translator/ParseContext.cpp

@@ -1605,7 +1605,7 @@ TFunction *TParseContext::addConstructorFunc(TPublicType publicType)
 //
 // Returns 0 for an error or the constructed node (aggregate or typed) for no error.
 //
-TIntermTyped *TParseContext::addConstructor(TIntermNode *arguments, const TType *type, TOperator op, TFunction *fnCall, const TSourceLoc &line)
+TIntermTyped *TParseContext::addConstructor(TIntermNode *arguments, TType *type, TOperator op, TFunction *fnCall, const TSourceLoc &line)
 {
     TIntermAggregate *aggregateArguments = arguments->getAsAggregate();
 
@@ -1633,13 +1633,21 @@ TIntermTyped *TParseContext::addConstructor(TIntermNode *arguments, const TType
     }
 
     // Turn the argument list itself into a constructor
-    TIntermTyped *constructor = intermediate.setAggregateOperator(aggregateArguments, op, line);
-    TIntermTyped *constConstructor = foldConstConstructor(constructor->getAsAggregate(), *type);
+    TIntermAggregate *constructor = intermediate.setAggregateOperator(aggregateArguments, op, line);
+    TIntermTyped *constConstructor = foldConstConstructor(constructor, *type);
     if (constConstructor)
     {
         return constConstructor;
     }
 
+    // Structs should not be precision qualified, the individual members may be.
+    // Built-in types on the other hand should be precision qualified.
+    if (op != EOpConstructStruct)
+    {
+        constructor->setPrecisionFromChildren();
+        type->setPrecision(constructor->getPrecision());
+    }
+
     return constructor;
 }
 

src/compiler/translator/ParseContext.h

@@ -136,7 +136,7 @@ struct TParseContext {
     TIntermAggregate* parseInitDeclarator(TPublicType &publicType, TIntermAggregate *declaratorList, const TSourceLoc& identifierLocation, const TString &identifier, const TSourceLoc& initLocation, TIntermTyped *initializer);
     void parseGlobalLayoutQualifier(const TPublicType &typeQualifier);
     TFunction *addConstructorFunc(TPublicType publicType);
-    TIntermTyped* addConstructor(TIntermNode*, const TType*, TOperator, TFunction*, const TSourceLoc&);
+    TIntermTyped* addConstructor(TIntermNode*, TType*, TOperator, TFunction*, const TSourceLoc&);
     TIntermTyped* foldConstConstructor(TIntermAggregate* aggrNode, const TType& type);
     TIntermTyped* addConstVectorNode(TVectorFields&, TIntermTyped*, const TSourceLoc&);
     TIntermTyped* addConstMatrixNode(int , TIntermTyped*, const TSourceLoc&);

tests/compiler_tests/TypeTracking_test.cpp

@@ -215,3 +215,34 @@ TEST_F(TypeTrackingTest, TextureSizeResultTypeAndPrecision)
     compile(shaderString);
     ASSERT_TRUE(foundInIntermediateTree("textureSize(s21;i1; (highp 2-component vector of int)"));
 };
+
+TEST_F(TypeTrackingTest, BuiltInConstructorResultTypeAndPrecision)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "uniform float u1;\n"
+        "uniform float u2;\n"
+        "uniform float u3;\n"
+        "uniform float u4;\n"
+        "void main() {\n"
+        "   vec4 a = vec4(u1, u2, u3, u4);\n"
+        "   gl_FragColor = a;\n"
+        "}\n";
+    compile(shaderString);
+    ASSERT_TRUE(foundInIntermediateTree("Construct vec4 (mediump 4-component vector of float)"));
+};
+
+TEST_F(TypeTrackingTest, StructConstructorResultNoPrecision)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "uniform vec4 u1;\n"
+        "uniform vec4 u2;\n"
+        "struct S { highp vec4 a; highp vec4 b; };\n"
+        "void main() {\n"
+        "   S s = S(u1, u2);\n"
+        "   gl_FragColor = s.a;\n"
+        "}\n";
+    compile(shaderString);
+    ASSERT_TRUE(foundInIntermediateTree("Construct structure (structure)"));
+};