Disallow structs as scalar/vector constructor arguments

src/compiler/translator/ParseContext.cpp

@@ -640,6 +640,12 @@ bool TParseContext::checkConstructorArguments(const TSourceLoc &line,
             const TIntermTyped *argTyped = arg->getAsTyped();
             ASSERT(argTyped != nullptr);
 
+            if (argTyped->getBasicType() == EbtStruct)
+            {
+                error(line, "a struct cannot be used as a constructor argument for this type",
+                      "constructor");
+                return false;
+            }
             if (argTyped->getType().isArray())
             {
                 error(line, "constructing from a non-dereferenced array", "constructor");
@@ -655,7 +661,7 @@ bool TParseContext::checkConstructorArguments(const TSourceLoc &line,
             {
                 overFull = true;
             }
-            if (type.getBasicType() != EbtStruct && !type.isArray() && size >= type.getObjectSize())
+            if (size >= type.getObjectSize())
             {
                 full = true;
             }

src/tests/compiler_tests/ShaderValidation_test.cpp

@@ -3858,3 +3858,24 @@ TEST_F(FragmentShaderValidationTest, InvalidInterfaceBlockTernaryExpression)
         FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
     }
 }
+
+// Test that a struct can not be used as a constructor argument for a scalar.
+TEST_F(FragmentShaderValidationTest, StructAsBoolConstructorArgument)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "struct my_struct\n"
+        "{\n"
+        "    float f;\n"
+        "};\n"
+        "my_struct a = my_struct(1.0);\n"
+        "void main(void)\n"
+        "{\n"
+        "    bool test = bool(a);\n"
+        "}\n";
+
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
+    }
+}