Fix array.length() to return a signed integer

src/compiler/translator/ParseContext.cpp

@@ -3148,7 +3148,7 @@ TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall, TIntermN
     if (thisNode != nullptr)
     {
         ConstantUnion *unionArray = new ConstantUnion[1];
-        unsigned int arraySize = 0;
+        int arraySize = 0;
         TIntermTyped *typedThis = thisNode->getAsTyped();
         if (fnCall->getName() != "length")
         {
@@ -3167,7 +3167,7 @@ TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall, TIntermN
         }
         else
         {
-            arraySize = static_cast<unsigned int>(typedThis->getArraySize());
+            arraySize = typedThis->getArraySize();
             if (typedThis->hasSideEffects())
             {
                 // This code path can be hit with an expression like this:
@@ -3176,8 +3176,8 @@ TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall, TIntermN
                 UNIMPLEMENTED();
             }
         }
-        unionArray->setUConst(arraySize);
-        callNode = intermediate.addConstantUnion(unionArray, TType(EbtUInt, EbpUndefined, EvqConst), loc);
+        unionArray->setIConst(arraySize);
+        callNode = intermediate.addConstantUnion(unionArray, TType(EbtInt, EbpUndefined, EvqConst), loc);
     }
     else if (op != EOpNull)
     {

src/tests/compiler_tests/MalformedShader_test.cpp

@@ -422,3 +422,22 @@ TEST_F(MalformedShaderTest, TernaryOperatorOnStructs)
         FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
     }
 }
+
+// Array length() returns a constant signed integral expression (ESSL 3.00 section 4.1.9)
+// Assigning it to unsigned should result in an error.
+TEST_F(MalformedShaderTest, AssignArrayLengthToUnsigned)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "out vec4 my_FragColor;\n"
+        "void main() {\n"
+        "   int[1] arr;\n"
+        "   uint l = arr.length();\n"
+        "   my_FragColor = vec4(float(l));\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}