Better main function recognition and tests

compiler/backend/src/org/jetbrains/kotlin/codegen/state/JetTypeMapper.java

@@ -30,8 +30,6 @@ import org.jetbrains.kotlin.codegen.binding.PsiCodegenPredictor;
 import org.jetbrains.kotlin.codegen.context.CodegenContext;
 import org.jetbrains.kotlin.codegen.signature.BothSignatureWriter;
 import org.jetbrains.kotlin.descriptors.*;
-import org.jetbrains.kotlin.descriptors.annotations.Annotated;
-import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.kotlin.load.java.JvmAbi;
 import org.jetbrains.kotlin.load.java.descriptors.JavaCallableMemberDescriptor;
 import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor;
@@ -54,8 +52,6 @@ import org.jetbrains.kotlin.resolve.annotations.AnnotationsPackage;
 import org.jetbrains.kotlin.resolve.calls.model.DefaultValueArgument;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedValueArgument;
-import org.jetbrains.kotlin.resolve.constants.ConstantValue;
-import org.jetbrains.kotlin.resolve.constants.StringValue;
 import org.jetbrains.kotlin.resolve.jvm.AsmTypes;
 import org.jetbrains.kotlin.resolve.jvm.JvmClassName;
 import org.jetbrains.kotlin.resolve.jvm.JvmPrimitiveType;
@@ -71,7 +67,6 @@ import org.jetbrains.org.objectweb.asm.commons.Method;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 import static org.jetbrains.kotlin.builtins.KotlinBuiltIns.isUnit;
 import static org.jetbrains.kotlin.codegen.AsmUtil.*;
@@ -716,20 +711,6 @@ public class JetTypeMapper {
         }
     }
 
-    @Nullable
-    private static String getPlatformName(@NotNull Annotated descriptor) {
-        AnnotationDescriptor platformNameAnnotation = descriptor.getAnnotations().findAnnotation(new FqName("kotlin.platform.platformName"));
-        if (platformNameAnnotation == null) return null;
-
-        Map<ValueParameterDescriptor, ConstantValue<?>> arguments = platformNameAnnotation.getAllValueArguments();
-        if (arguments.isEmpty()) return null;
-
-        ConstantValue<?> name = arguments.values().iterator().next();
-        if (!(name instanceof StringValue)) return null;
-
-        return ((StringValue) name).getValue();
-    }
-
     @NotNull
     public JvmMethodSignature mapSignature(@NotNull FunctionDescriptor descriptor) {
         return mapSignature(descriptor, OwnerKind.IMPLEMENTATION);

compiler/frontend/src/org/jetbrains/kotlin/idea/MainFunctionDetector.java

@@ -29,13 +29,11 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils;
 import org.jetbrains.kotlin.resolve.annotations.AnnotationsPackage;
 import org.jetbrains.kotlin.types.JetType;
 import org.jetbrains.kotlin.types.TypeProjection;
-import org.jetbrains.kotlin.types.checker.JetTypeChecker;
+import org.jetbrains.kotlin.types.Variance;
 
 import java.util.Collection;
 import java.util.List;
 
-import static org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilPackage.getBuiltIns;
-
 public class MainFunctionDetector {
     private final NotNullFunction<JetNamedFunction, FunctionDescriptor> getFunctionDescriptor;
 
@@ -63,9 +61,15 @@ public class MainFunctionDetector {
     }
 
     public boolean isMain(@NotNull JetNamedFunction function) {
-        if (!"main".equals(function.getName())) return false;
+        if (!"main".equals(function.getName()) && function.getAnnotationEntries().isEmpty()) {
+            return false;
+        }
 
         FunctionDescriptor functionDescriptor = getFunctionDescriptor.fun(function);
+        if (!getJVMFunctionName(functionDescriptor).equals("main")) {
+            return false;
+        }
+
         List<ValueParameterDescriptor> parameters = functionDescriptor.getValueParameters();
         if (parameters.size() != 1) return false;
 
@@ -77,7 +81,12 @@ public class MainFunctionDetector {
         if (typeArguments.size() != 1) return false;
 
         JetType typeArgument = typeArguments.get(0).getType();
-        if (!JetTypeChecker.DEFAULT.equalTypes(typeArgument, getBuiltIns(functionDescriptor).getStringType())) return false;
+        if (!KotlinBuiltIns.isString(typeArgument)) {
+            return false;
+        }
+        if (typeArguments.get(0).getProjectionKind() != Variance.INVARIANT) {
+            return false;
+        }
 
         if (DescriptorUtils.isTopLevelDeclaration(functionDescriptor)) return true;
 
@@ -110,4 +119,14 @@ public class MainFunctionDetector {
         }
         return null;
     }
+
+    @NotNull
+    private static String getJVMFunctionName(FunctionDescriptor functionDescriptor) {
+        String platformName = DescriptorUtils.getPlatformName(functionDescriptor);
+        if (platformName != null) {
+            return platformName;
+        }
+
+        return functionDescriptor.getName().asString();
+    }
 }