diff options
Diffstat (limited to 'linker/Linker/MethodBodyScanner.cs')
| -rw-r--r-- | linker/Linker/MethodBodyScanner.cs | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/linker/Linker/MethodBodyScanner.cs b/linker/Linker/MethodBodyScanner.cs new file mode 100644 index 000000000..f875ad162 --- /dev/null +++ b/linker/Linker/MethodBodyScanner.cs @@ -0,0 +1,119 @@ +using System; +using System.Collections.Generic; +using System.Linq; +using Mono.Cecil; +using Mono.Cecil.Cil; + +namespace Mono.Linker { + public static class MethodBodyScanner { + public static IEnumerable<InterfaceImplementation> GetReferencedInterfaces (AnnotationStore annotations, MethodBody body) + { + var possibleStackTypes = AllPossibleStackTypes (body.Method); + if (possibleStackTypes.Count == 0) + return null; + + var interfaceTypes = possibleStackTypes.Where (t => t.IsInterface).ToArray (); + if (interfaceTypes.Length == 0) + return null; + + var interfaceImplementations = new HashSet<InterfaceImplementation> (); + + // If a type could be on the stack in the body and an interface it implements could be on the stack on the body + // then we need to mark that interface implementation. When this occurs it is not safe to remove the interface implementation from the type + // even if the type is never instantiated + foreach (var type in possibleStackTypes) { + // We only sweep interfaces on classes so that's why we only care about classes + if (!type.IsClass) + continue; + + AddMatchingInterfaces (interfaceImplementations, type, interfaceTypes); + var bases = annotations.GetClassHierarchy (type); + foreach (var @base in bases) { + AddMatchingInterfaces (interfaceImplementations, @base, interfaceTypes); + } + } + + return interfaceImplementations; + } + + static HashSet<TypeDefinition> AllPossibleStackTypes (MethodDefinition method) + { + if (!method.HasBody) + throw new ArgumentException(); + + var body = method.Body; + var types = new HashSet<TypeDefinition> (); + + foreach (VariableDefinition var in body.Variables) + AddIfResolved (types, var.VariableType); + + foreach (ExceptionHandler eh in body.ExceptionHandlers) { + if (eh.HandlerType == ExceptionHandlerType.Catch) { + AddIfResolved (types, eh.CatchType); + } + } + + foreach (Instruction instruction in body.Instructions) { + if (instruction.Operand is FieldReference fieldReference) { + AddIfResolved (types, fieldReference.Resolve ()?.FieldType); + } else if (instruction.Operand is MethodReference methodReference) { + if (methodReference is GenericInstanceMethod genericInstanceMethod) + AddFromGenericInstance (types, genericInstanceMethod); + + if (methodReference.DeclaringType is GenericInstanceType genericInstanceType) + AddFromGenericInstance (types, genericInstanceType); + + var resolvedMethod = methodReference.Resolve (); + if (resolvedMethod != null) { + if (resolvedMethod.HasParameters) { + foreach (var param in resolvedMethod.Parameters) + AddIfResolved (types, param.ParameterType); + } + + AddFromGenericParameterProvider (types, resolvedMethod); + AddFromGenericParameterProvider (types, resolvedMethod.DeclaringType); + AddIfResolved (types, resolvedMethod.ReturnType); + } + } + } + + return types; + } + + static void AddMatchingInterfaces (HashSet<InterfaceImplementation> results, TypeDefinition type, TypeDefinition [] interfaceTypes) + { + foreach (var interfaceType in interfaceTypes) { + if (type.HasInterface (interfaceType, out InterfaceImplementation implementation)) + results.Add (implementation); + } + } + + static void AddFromGenericInstance (HashSet<TypeDefinition> set, IGenericInstance instance) + { + if (!instance.HasGenericArguments) + return; + + foreach (var genericArgument in instance.GenericArguments) + AddIfResolved (set, genericArgument); + } + + static void AddFromGenericParameterProvider (HashSet<TypeDefinition> set, IGenericParameterProvider provider) + { + if (!provider.HasGenericParameters) + return; + + foreach (var genericParameter in provider.GenericParameters) { + foreach (var constraint in genericParameter.Constraints) + AddIfResolved (set, constraint); + } + } + + static void AddIfResolved (HashSet<TypeDefinition> set, TypeReference item) + { + var resolved = item.Resolve (); + if (resolved == null) + return; + set.Add (resolved); + } + } +}
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