Basic inheritance functionality

Python inheritance is remarkably complicated... this commit implements the basics.
There are still a fair number of things that are unimplemented, and some things
like inheriting from all the basic types haven't been added yet.

src/analysis/function_analysis.cpp

@@ -201,6 +201,7 @@ public:
     virtual bool visit_print(AST_Print* node) { return true; }
     virtual bool visit_raise(AST_Raise* node) { return true; }
     virtual bool visit_return(AST_Return* node) { return true; }
+    virtual bool visit_unreachable(AST_Unreachable* node) { return true; }
 
     virtual bool visit_classdef(AST_ClassDef* node) {
         _doSet(node->name);

src/analysis/type_analysis.cpp

@@ -510,6 +510,8 @@ private:
         }
     }
 
+    virtual void visit_unreachable(AST_Unreachable* node) {}
+
 public:
     static void propagate(CFGBlock* block, const TypeMap& starting, TypeMap& ending, ExprTypeMap& expr_types,
                           TypeSpeculations& type_speculations, TypeAnalysis::SpeculationLevel speculation,

src/asm_writing/rewriter2.cpp

@@ -138,7 +138,7 @@ RewriterVarUsage2 RewriterVarUsage2::getAttr(int offset, KillFlag kill, Location
     assembler::Register this_reg = var->getInReg();
     Rewriter2* rewriter = var->rewriter;
 
-    if (kill) {
+    if (kill == Kill) {
         setDoneUsing();
     }
 
@@ -176,6 +176,7 @@ void RewriterVarUsage2::setDoneUsing() {
     assertValid();
     done_using = true;
     var->decUse();
+    var = NULL;
 }
 
 RewriterVarUsage2::RewriterVarUsage2(RewriterVarUsage2&& usage) {

src/asm_writing/rewriter2.h

@@ -141,10 +141,6 @@ public:
     // semantically we have to pass the ownership of the use.
     RewriterVarUsage2(RewriterVarUsage2&& usage);
     RewriterVarUsage2& operator=(RewriterVarUsage2&& usage);
-    // assert(this->var == NULL)
-    // assert(this->done_using)
-    // assert(usage->var != NULL)
-    // assert(!usage->done_using)
 
     static RewriterVarUsage2 empty();
 
@@ -156,12 +152,6 @@ public:
 #endif
 
     void setDoneUsing();
-    // void setDoneUsing() {
-    // assert(!done_using);
-    // done_using = true;
-    //
-    // var->delUse();
-    //}
 
     // RewriterVarUsage2 addUse() { return var->addUse(); }
     RewriterVarUsage2 addUse();

src/codegen/compvars.cpp

@@ -1306,6 +1306,11 @@ public:
     virtual CompilerType* getattrType(const std::string* attr, bool cls_only) {
         return BOXED_TUPLE->getattrType(attr, cls_only);
     }
+
+    virtual CompilerVariable* callattr(IREmitter& emitter, const OpInfo& info, VAR* var, const std::string* attr,
+                                       bool clsonly, const std::vector<CompilerVariable*>& args) {
+        return makeConverted(emitter, var, getConcreteType())->callattr(emitter, info, attr, clsonly, args);
+    }
 };
 
 CompilerType* makeTupleType(const std::vector<CompilerType*>& elt_types) {

src/codegen/irgen/irgenerator.cpp

@@ -1307,16 +1307,19 @@ private:
 
         ScopeInfo* scope_info = irstate->getSourceInfo()->scoping->getScopeInfoForNode(node);
 
+        RELEASE_ASSERT(node->bases.size() == 1, "");
+
+        CompilerVariable* base = evalExpr(node->bases[0], exc_info);
+        ConcreteCompilerVariable* converted_base = base->makeConverted(emitter, base->getBoxType());
+        base->decvref(emitter);
+
         llvm::Value* classobj
-            = emitter.createCall2(exc_info, g.funcs.createUserClass, embedConstantPtr(&node->name, g.llvm_str_type_ptr),
+            = emitter.createCall3(exc_info, g.funcs.createUserClass, embedConstantPtr(&node->name, g.llvm_str_type_ptr),
+                                  converted_base->getValue(),
                                   embedConstantPtr(irstate->getSourceInfo()->parent_module, g.llvm_module_type_ptr))
                   .getInstruction();
         ConcreteCompilerVariable* cls = new ConcreteCompilerVariable(typeFromClass(type_cls), classobj, true);
 
-        RELEASE_ASSERT(node->bases.size() == 1, "");
-        RELEASE_ASSERT(node->bases[0]->type == AST_TYPE::Name, "");
-        RELEASE_ASSERT(ast_cast<AST_Name>(node->bases[0])->id == "object", "");
-
         // CompilerVariable* name = makeStr(&node->name);
         // cls->setattr(emitter, "__name__", name);
         // name->decvref(emitter);
@@ -1820,6 +1823,10 @@ private:
             case AST_TYPE::Raise:
                 doRaise(ast_cast<AST_Raise>(node), exc_info);
                 break;
+            case AST_TYPE::Unreachable:
+                emitter.getBuilder()->CreateUnreachable();
+                endBlock(FINISHED);
+                break;
             default:
                 printf("Unhandled stmt type at " __FILE__ ":" STRINGIFY(__LINE__) ": %d\n", node->type);
                 exit(1);

src/codegen/patchpoints.cpp

@@ -140,7 +140,10 @@ PatchpointSetupInfo* createSetattrPatchpoint(CompiledFunction* parent_cf, TypeRe
 }
 
 PatchpointSetupInfo* createCallsitePatchpoint(CompiledFunction* parent_cf, TypeRecorder* type_recorder, int num_args) {
-    return PatchpointSetupInfo::initialize(true, 3, 320 + 36 * num_args, parent_cf, Callsite, type_recorder);
+    // TODO These are very large, but could probably be made much smaller with IC optimizations
+    // - using rewriter2 for better code
+    // - not emitting duplicate guards
+    return PatchpointSetupInfo::initialize(true, 3, 480 + 48 * num_args, parent_cf, Callsite, type_recorder);
 }
 
 PatchpointSetupInfo* createGetGlobalPatchpoint(CompiledFunction* parent_cf, TypeRecorder* type_recorder) {
@@ -148,7 +151,7 @@ PatchpointSetupInfo* createGetGlobalPatchpoint(CompiledFunction* parent_cf, Type
 }
 
 PatchpointSetupInfo* createBinexpPatchpoint(CompiledFunction* parent_cf, TypeRecorder* type_recorder) {
-    return PatchpointSetupInfo::initialize(true, 4, 256, parent_cf, Binexp, type_recorder);
+    return PatchpointSetupInfo::initialize(true, 4, 320, parent_cf, Binexp, type_recorder);
 }
 
 PatchpointSetupInfo* createNonzeroPatchpoint(CompiledFunction* parent_cf, TypeRecorder* type_recorder) {

src/codegen/runtime_hooks.cpp

@@ -184,8 +184,6 @@ void initGlobalFuncs(GlobalState& g) {
     GET(printFloat);
     GET(listAppendInternal);
 
-    GET(dump);
-
     g.funcs.runtimeCall = getFunc((void*)runtimeCall, "runtimeCall");
     g.funcs.runtimeCall0 = addFunc((void*)runtimeCall, g.llvm_value_type_ptr, g.llvm_value_type_ptr, g.i64);
     g.funcs.runtimeCall1

src/codegen/runtime_hooks.h

@@ -33,7 +33,6 @@ struct GlobalFuncs {
     llvm::Value* checkUnpackingLength, *raiseAttributeError, *raiseAttributeErrorStr, *raiseNotIterableError,
         *assertNameDefined, *assertFail;
     llvm::Value* printFloat, *listAppendInternal;
-    llvm::Value* dump;
     llvm::Value* runtimeCall0, *runtimeCall1, *runtimeCall2, *runtimeCall3, *runtimeCall;
     llvm::Value* callattr0, *callattr1, *callattr2, *callattr3, *callattr;
     llvm::Value* reoptCompiledFunc, *compilePartialFunc;

src/core/ast.cpp

@@ -786,6 +786,16 @@ void* AST_UnaryOp::accept_expr(ExprVisitor* v) {
     return v->visit_unaryop(this);
 }
 
+void AST_Unreachable::accept(ASTVisitor* v) {
+    bool skip = v->visit_unreachable(this);
+    if (skip)
+        return;
+}
+
+void AST_Unreachable::accept_stmt(StmtVisitor* v) {
+    v->visit_unreachable(this);
+}
+
 void AST_While::accept(ASTVisitor* v) {
     bool skip = v->visit_while(this);
     if (skip)
@@ -1518,6 +1528,11 @@ bool PrintVisitor::visit_unaryop(AST_UnaryOp* node) {
     return true;
 }
 
+bool PrintVisitor::visit_unreachable(AST_Unreachable* node) {
+    printf("<unreachable>");
+    return true;
+}
+
 bool PrintVisitor::visit_while(AST_While* node) {
     printf("while ");
     node->test->accept(this);
@@ -1783,6 +1798,10 @@ public:
         output->push_back(node);
         return false;
     }
+    virtual bool visit_unreachable(AST_Unreachable* node) {
+        output->push_back(node);
+        return false;
+    }
     virtual bool visit_while(AST_While* node) {
         output->push_back(node);
         return false;

src/core/ast.h

@@ -124,6 +124,7 @@ enum AST_TYPE {
     AugBinOp = 203,
     Invoke = 204,
     LangPrimitive = 205,
+    Unreachable = 206,
 };
 };
 
@@ -857,6 +858,15 @@ public:
     static const AST_TYPE::AST_TYPE TYPE = AST_TYPE::LangPrimitive;
 };
 
+class AST_Unreachable : public AST_stmt {
+public:
+    virtual void accept(ASTVisitor* v);
+    virtual void accept_stmt(StmtVisitor* v);
+
+    AST_Unreachable() : AST_stmt(AST_TYPE::Unreachable) {}
+
+    static const AST_TYPE::AST_TYPE TYPE = AST_TYPE::Unreachable;
+};
 
 template <typename T> T* ast_cast(AST* node) {
     assert(node->type == T::TYPE);
@@ -919,6 +929,7 @@ public:
     virtual bool visit_tryfinally(AST_TryFinally* node) { RELEASE_ASSERT(0, ""); }
     virtual bool visit_tuple(AST_Tuple* node) { RELEASE_ASSERT(0, ""); }
     virtual bool visit_unaryop(AST_UnaryOp* node) { RELEASE_ASSERT(0, ""); }
+    virtual bool visit_unreachable(AST_Unreachable* node) { RELEASE_ASSERT(0, ""); }
     virtual bool visit_while(AST_While* node) { RELEASE_ASSERT(0, ""); }
     virtual bool visit_with(AST_With* node) { RELEASE_ASSERT(0, ""); }
 
@@ -980,6 +991,7 @@ public:
     virtual bool visit_tryfinally(AST_TryFinally* node) { return false; }
     virtual bool visit_tuple(AST_Tuple* node) { return false; }
     virtual bool visit_unaryop(AST_UnaryOp* node) { return false; }
+    virtual bool visit_unreachable(AST_Unreachable* node) { return false; }
     virtual bool visit_while(AST_While* node) { return false; }
     virtual bool visit_with(AST_With* node) { return false; }
 
@@ -1042,6 +1054,7 @@ public:
     virtual void visit_return(AST_Return* node) { RELEASE_ASSERT(0, ""); }
     virtual void visit_tryexcept(AST_TryExcept* node) { RELEASE_ASSERT(0, ""); }
     virtual void visit_tryfinally(AST_TryFinally* node) { RELEASE_ASSERT(0, ""); }
+    virtual void visit_unreachable(AST_Unreachable* node) { RELEASE_ASSERT(0, ""); }
     virtual void visit_while(AST_While* node) { RELEASE_ASSERT(0, ""); }
     virtual void visit_with(AST_With* node) { RELEASE_ASSERT(0, ""); }
 
@@ -1108,6 +1121,7 @@ public:
     virtual bool visit_tryexcept(AST_TryExcept* node);
     virtual bool visit_tryfinally(AST_TryFinally* node);
     virtual bool visit_unaryop(AST_UnaryOp* node);
+    virtual bool visit_unreachable(AST_Unreachable* node);
     virtual bool visit_while(AST_While* node);
     virtual bool visit_with(AST_With* node);
 

src/core/cfg.cpp

@@ -1310,6 +1310,10 @@ public:
         if (node->arg2)
             remapped->arg2 = remapExpr(node->arg2);
         push_back(remapped);
+
+        curblock->push_back(new AST_Unreachable());
+        curblock = NULL;
+
         return true;
     }
 
@@ -1331,10 +1335,12 @@ public:
         }
 
         CFGBlock* join_block = cfg->addDeferredBlock();
-        AST_Jump* j = new AST_Jump();
-        j->target = join_block;
-        push_back(j);
-        curblock->connectTo(join_block);
+        if (curblock) {
+            AST_Jump* j = new AST_Jump();
+            j->target = join_block;
+            push_back(j);
+            curblock->connectTo(join_block);
+        }
 
         if (exc_handler_block->predecessors.size() == 0) {
             delete exc_handler_block;
@@ -1357,11 +1363,12 @@ public:
                     is_caught_here->args.push_back(handled_type);
                     is_caught_here->args.push_back(makeNum(1)); // flag: false_on_noncls
 
+                    AST_Branch* br = new AST_Branch();
+                    br->test = remapExpr(is_caught_here);
+
                     CFGBlock* exc_handle = cfg->addBlock();
                     exc_next = cfg->addDeferredBlock();
 
-                    AST_Branch* br = new AST_Branch();
-                    br->test = remapExpr(is_caught_here);
                     br->iftrue = exc_handle;
                     br->iffalse = exc_next;
                     curblock->connectTo(exc_handle);
@@ -1380,10 +1387,12 @@ public:
                     subnode->accept(this);
                 }
 
-                AST_Jump* j = new AST_Jump();
-                j->target = join_block;
-                push_back(j);
-                curblock->connectTo(join_block);
+                if (curblock) {
+                    AST_Jump* j = new AST_Jump();
+                    j->target = join_block;
+                    push_back(j);
+                    curblock->connectTo(join_block);
+                }
 
                 if (exc_next) {
                     cfg->placeBlock(exc_next);
@@ -1397,12 +1406,19 @@ public:
                 AST_Raise* raise = new AST_Raise();
                 raise->arg0 = exc_obj;
                 push_back(raise);
+                curblock->push_back(new AST_Unreachable());
                 curblock = NULL;
             }
         }
 
-        cfg->placeBlock(join_block);
-        curblock = join_block;
+        if (join_block->predecessors.size() == 0) {
+            delete join_block;
+            curblock = NULL;
+        } else {
+            cfg->placeBlock(join_block);
+            curblock = join_block;
+        }
+
         return true;
     }
 
@@ -1579,9 +1595,13 @@ CFG* computeCFG(AST_TYPE::AST_TYPE root_type, std::vector<AST_stmt*> body) {
             ASSERT(b2->idx != -1, "Forgot to place a block!");
         }
 
+        ASSERT(b->body.size(), "%d", b->idx);
         ASSERT(b->successors.size() <= 2, "%d has too many successors!", b->idx);
-        if (b->successors.size() == 0)
-            assert(b->body.back()->type == AST_TYPE::Return || b->body.back()->type == AST_TYPE::Raise);
+        if (b->successors.size() == 0) {
+            AST_stmt* terminator = b->body.back();
+            assert(terminator->type == AST_TYPE::Return || terminator->type == AST_TYPE::Raise
+                   || terminator->type == AST_TYPE::Unreachable);
+        }
 
         if (b->predecessors.size() == 0)
             assert(b == rtn->getStartingBlock());

src/core/types.h

@@ -66,11 +66,8 @@ public:
 extern "C" const AllocationKind untracked_kind, conservative_kind;
 
 class ObjectFlavor;
-extern "C" const ObjectFlavor user_flavor;
 class ObjectFlavor : public AllocationKind {
 public:
-    bool isUserDefined() const { return this == &user_flavor; }
-
     ObjectFlavor(GCHandler gc_handler, FinalizationFunc finalizer) __attribute__((visibility("default")))
     : AllocationKind(gc_handler, finalizer) {}
 };
@@ -350,6 +347,10 @@ public:
     // to guard on anything about the class.
     ICInvalidator dependent_icgetattrs;
 
+    // Only a single base supported for now.
+    // Is NULL iff this is object_cls
+    BoxedClass* const base;
+
     // Offset of the HCAttrs object or 0 if there are no hcattrs.
     // Analogous to tp_dictoffset
     const int attrs_offset;
@@ -371,7 +372,7 @@ public:
     // will need to update this once we support tp_getattr-style overriding:
     bool hasGenericGetattr() { return true; }
 
-    BoxedClass(int attrs_offset, int instance_size, bool is_user_defined);
+    BoxedClass(BoxedClass* base, int attrs_offset, int instance_size, bool is_user_defined);
     void freeze() {
         assert(!is_constant);
         is_constant = true;

src/runtime/builtin_modules/builtins.cpp

@@ -369,8 +369,8 @@ Box* exceptionRepr(Box* b) {
     return boxString(*getTypeName(b) + "(" + message_s->s + ",)");
 }
 
-static BoxedClass* makeBuiltinException(const char* name) {
-    BoxedClass* cls = new BoxedClass(offsetof(BoxedException, attrs), sizeof(BoxedException), false);
+static BoxedClass* makeBuiltinException(BoxedClass* base, const char* name) {
+    BoxedClass* cls = new BoxedClass(base, offsetof(BoxedException, attrs), sizeof(BoxedException), false);
     cls->giveAttr("__name__", boxStrConstant(name));
 
     // TODO these should be on the base Exception class:
@@ -388,7 +388,7 @@ void setupBuiltins() {
 
     builtins_module->giveAttr("None", None);
 
-    notimplemented_cls = new BoxedClass(0, sizeof(Box), false);
+    notimplemented_cls = new BoxedClass(object_cls, 0, sizeof(Box), false);
     notimplemented_cls->giveAttr("__name__", boxStrConstant("NotImplementedType"));
     notimplemented_cls->giveAttr("__repr__",
                                  new BoxedFunction(boxRTFunction((void*)notimplementedRepr, NULL, 1, false)));
@@ -402,20 +402,20 @@ void setupBuiltins() {
     builtins_module->giveAttr("all", new BoxedFunction(boxRTFunction((void*)all, BOXED_BOOL, 1, false)));
     builtins_module->giveAttr("any", new BoxedFunction(boxRTFunction((void*)any, BOXED_BOOL, 1, false)));
 
-    Exception = makeBuiltinException("Exception");
-    AssertionError = makeBuiltinException("AssertionError");
-    AttributeError = makeBuiltinException("AttributeError");
-    TypeError = makeBuiltinException("TypeError");
-    NameError = makeBuiltinException("NameError");
-    KeyError = makeBuiltinException("KeyError");
-    IndexError = makeBuiltinException("IndexError");
-    IOError = makeBuiltinException("IOError");
-    OSError = makeBuiltinException("OSError");
-    ZeroDivisionError = makeBuiltinException("ZeroDivisionError");
-    ValueError = makeBuiltinException("ValueError");
-    UnboundLocalError = makeBuiltinException("UnboundLocalError");
-    RuntimeError = makeBuiltinException("RuntimeError");
-    ImportError = makeBuiltinException("ImportError");
+    Exception = makeBuiltinException(object_cls, "Exception");
+    AssertionError = makeBuiltinException(Exception, "AssertionError");
+    AttributeError = makeBuiltinException(Exception, "AttributeError");
+    TypeError = makeBuiltinException(Exception, "TypeError");
+    NameError = makeBuiltinException(Exception, "NameError");
+    KeyError = makeBuiltinException(Exception, "KeyError");
+    IndexError = makeBuiltinException(Exception, "IndexError");
+    IOError = makeBuiltinException(Exception, "IOError");
+    OSError = makeBuiltinException(Exception, "OSError");
+    ZeroDivisionError = makeBuiltinException(Exception, "ZeroDivisionError");
+    ValueError = makeBuiltinException(Exception, "ValueError");
+    UnboundLocalError = makeBuiltinException(Exception, "UnboundLocalError");
+    RuntimeError = makeBuiltinException(Exception, "RuntimeError");
+    ImportError = makeBuiltinException(Exception, "ImportError");
 
     repr_obj = new BoxedFunction(boxRTFunction((void*)repr, NULL, 1, false));
     builtins_module->giveAttr("repr", repr_obj);
@@ -476,6 +476,7 @@ void setupBuiltins() {
     builtins_module->giveAttr("map", new BoxedFunction(boxRTFunction((void*)map2, LIST, 2, false)));
     builtins_module->giveAttr("zip", new BoxedFunction(boxRTFunction((void*)zip2, LIST, 2, false)));
 
+    builtins_module->giveAttr("object", object_cls);
     builtins_module->giveAttr("str", str_cls);
     builtins_module->giveAttr("int", int_cls);
     builtins_module->giveAttr("float", float_cls);

src/runtime/capi.cpp

@@ -120,7 +120,7 @@ BoxedModule* getTestModule() {
 }
 
 void setupCAPI() {
-    capifunc_cls = new BoxedClass(0, sizeof(BoxedCApiFunction), false);
+    capifunc_cls = new BoxedClass(object_cls, 0, sizeof(BoxedCApiFunction), false);
     capifunc_cls->giveAttr("__name__", boxStrConstant("capifunc"));
 
     capifunc_cls->giveAttr("__repr__",

src/runtime/inline/link_forcer.cpp

@@ -86,8 +86,6 @@ void force() {
     FORCE(printFloat);
     FORCE(listAppendInternal);
 
-    FORCE(dump);
-
     FORCE(runtimeCall);
     FORCE(callattr);
 

src/runtime/inline/xrange.cpp

@@ -120,9 +120,9 @@ Box* xrangeIter(Box* self) {
 }
 
 void setupXrange() {
-    xrange_cls = new BoxedClass(0, sizeof(BoxedXrange), false);
+    xrange_cls = new BoxedClass(object_cls, 0, sizeof(BoxedXrange), false);
     xrange_cls->giveAttr("__name__", boxStrConstant("xrange"));
-    xrange_iterator_cls = new BoxedClass(0, sizeof(BoxedXrangeIterator), false);
+    xrange_iterator_cls = new BoxedClass(object_cls, 0, sizeof(BoxedXrangeIterator), false);
     xrange_iterator_cls->giveAttr("__name__", boxStrConstant("rangeiterator"));
 
     CLFunction* xrange_clf = boxRTFunction((void*)xrange1, NULL, 2, false);

src/runtime/list.cpp

@@ -433,7 +433,7 @@ extern "C" Box* listNew2(Box* cls, Box* container) {
 }
 
 void setupList() {
-    list_iterator_cls = new BoxedClass(0, sizeof(BoxedList), false);
+    list_iterator_cls = new BoxedClass(object_cls, 0, sizeof(BoxedList), false);
 
     list_cls->giveAttr("__name__", boxStrConstant("list"));
 

src/runtime/objmodel.cpp

@@ -34,6 +34,8 @@
 #include "core/options.h"
 #include "core/stats.h"
 #include "core/types.h"
+#include "gc/collector.h"
+#include "gc/heap.h"
 #include "runtime/capi.h"
 #include "runtime/float.h"
 #include "runtime/gc_runtime.h"
@@ -216,6 +218,16 @@ extern "C" void my_assert(bool b) {
     assert(b);
 }
 
+extern "C" bool isSubclass(BoxedClass* child, BoxedClass* parent) {
+    // TODO the class is allowed to override this using __subclasscheck__
+    while (child) {
+        if (child == parent)
+            return true;
+        child = child->base;
+    }
+    return false;
+}
+
 extern "C" void assertFail(BoxedModule* inModule, Box* msg) {
     if (msg) {
         BoxedString* tostr = str(msg);
@@ -263,9 +275,24 @@ extern "C" void checkUnpackingLength(i64 expected, i64 given) {
     }
 }
 
-BoxedClass::BoxedClass(int attrs_offset, int instance_size, bool is_user_defined)
-    : Box(&type_flavor, type_cls), attrs_offset(attrs_offset), instance_size(instance_size), is_constant(false),
-      is_user_defined(is_user_defined) {
+BoxedClass::BoxedClass(BoxedClass* base, int attrs_offset, int instance_size, bool is_user_defined)
+    : Box(&type_flavor, type_cls), base(base), attrs_offset(attrs_offset), instance_size(instance_size),
+      is_constant(false), is_user_defined(is_user_defined) {
+
+    if (!base) {
+        assert(object_cls == nullptr);
+        // we're constructing 'object'
+        // Will have to add __base__ = None later
+    } else {
+        assert(object_cls);
+        if (base->attrs_offset)
+            RELEASE_ASSERT(attrs_offset == base->attrs_offset, "");
+        assert(instance_size >= base->instance_size);
+    }
+
+    if (base && cls && str_cls)
+        giveAttr("__base__", base);
+
     assert(instance_size % sizeof(void*) == 0); // Not critical I suppose, but probably signals a bug
     if (attrs_offset) {
         assert(instance_size >= attrs_offset + sizeof(HCAttrs));
@@ -315,7 +342,6 @@ Box::Box(const ObjectFlavor* flavor, BoxedClass* cls) : GCObject(flavor), cls(cl
     if (cls == NULL) {
         assert(type_cls == NULL);
     } else {
-        assert(flavor->isUserDefined() == isUserDefined(cls));
     }
 }
 
@@ -396,6 +422,9 @@ Box* Box::getattr(const std::string& attr, GetattrRewriteArgs* rewrite_args, Get
     return rtn;
 }
 
+// TODO should centralize all of these:
+static const std::string _call_str("__call__"), _new_str("__new__"), _init_str("__init__");
+
 void Box::setattr(const std::string& attr, Box* val, SetattrRewriteArgs2* rewrite_args2) {
     assert(cls->instancesHaveAttrs());
 
@@ -418,14 +447,21 @@ void Box::setattr(const std::string& attr, Box* val, SetattrRewriteArgs2* rewrit
 
     RELEASE_ASSERT(attr != none_str || this == builtins_module, "can't assign to None");
 
-    if ((this->cls == type_cls) && (attr == getattr_str || attr == getattribute_str)) {
-        // Will have to embed the clear in the IC, so just disable the patching for now:
-        rewrite_args2 = NULL;
-
-        // TODO should put this clearing behavior somewhere else, since there are probably more
-        // cases in which we want to do it.
+    if (isSubclass(this->cls, type_cls)) {
         BoxedClass* self = static_cast<BoxedClass*>(this);
-        self->dependent_icgetattrs.invalidateAll();
+
+        if (attr == getattr_str || attr == getattribute_str) {
+            // Will have to embed the clear in the IC, so just disable the patching for now:
+            rewrite_args2 = NULL;
+
+            // TODO should put this clearing behavior somewhere else, since there are probably more
+            // cases in which we want to do it.
+            self->dependent_icgetattrs.invalidateAll();
+        }
+
+        if (attr == "__base__" && getattr("__base__")) {
+            raiseExcHelper(TypeError, "readonly attribute");
+        }
     }
 
     HCAttrs* attrs = getAttrs();
@@ -541,14 +577,29 @@ Box* typeLookup(BoxedClass* cls, const std::string& attr, GetattrRewriteArgs* re
         assert(!rewrite_args->out_success);
 
         val = cls->getattr(attr, rewrite_args, NULL);
+        assert(rewrite_args->out_success);
+        if (!val and cls->base) {
+            rewrite_args->out_success = false;
+            rewrite_args->obj = rewrite_args->obj.getAttr(offsetof(BoxedClass, base), rewrite_args->preferred_dest_reg);
+            return typeLookup(cls->base, attr, rewrite_args, NULL);
+        }
         return val;
     } else if (rewrite_args2) {
         assert(!rewrite_args2->out_success);
 
         val = cls->getattr(attr, NULL, rewrite_args2);
+        assert(rewrite_args2->out_success);
+        if (!val and cls->base) {
+            rewrite_args2->out_success = false;
+            rewrite_args2->obj = rewrite_args2->obj.getAttr(offsetof(BoxedClass, base), RewriterVarUsage2::Kill);
+            return typeLookup(cls->base, attr, NULL, rewrite_args2);
+        }
         return val;
     } else {
-        return cls->getattr(attr, NULL, NULL);
+        val = cls->getattr(attr, NULL, NULL);
+        if (!val and cls->base)
+            return typeLookup(cls->base, attr, NULL, NULL);
+        return val;
     }
 }
 
@@ -1038,8 +1089,8 @@ extern "C" bool isinstance(Box* obj, Box* cls, int64_t flags) {
 
     BoxedClass* ccls = static_cast<BoxedClass*>(cls);
 
-    // TODO more complicated than this, but there's no inheritance yet...
-    return ccls == obj->cls;
+    // TODO the class is allowed to override this using __instancecheck__
+    return isSubclass(obj->cls, ccls);
 }
 
 extern "C" BoxedInt* hash(Box* obj) {
@@ -1136,8 +1187,36 @@ extern "C" void print(Box* obj) {
     printf("%s", strd->s.c_str());
 }
 
-extern "C" void dump(Box* obj) {
-    printf("dump: obj %p, cls %p\n", obj, obj->cls);
+extern "C" void dump(void* p) {
+    printf("\n");
+    bool is_gc = (gc::global_heap.getAllocationFromInteriorPointer(p) != NULL);
+    if (!is_gc) {
+        printf("non-gc memory\n");
+        return;
+    }
+
+    GCObjectHeader* header = gc::headerFromObject(p);
+    if (header->kind_id == hc_kind.kind_id) {
+        printf("hcls object\n");
+        return;
+    }
+
+    if (header->kind_id == untracked_kind.kind_id) {
+        printf("untracked object\n");
+        return;
+    }
+
+    if (header->kind_id == conservative_kind.kind_id) {
+        printf("untracked object\n");
+        return;
+    }
+
+    printf("Assuming it's a Box*\n");
+    Box* b = (Box*)p;
+    printf("Class: %s\n", getTypeName(b)->c_str());
+    if (isSubclass(b->cls, type_cls)) {
+        printf("Type name: %s\n", getNameOfClass(static_cast<BoxedClass*>(b))->c_str());
+    }
 }
 
 // For rewriting purposes, this function assumes that nargs will be constant.
@@ -1472,7 +1551,6 @@ extern "C" Box* callattr(Box* obj, std::string* attr, bool clsonly, int64_t narg
     return rtn;
 }
 
-static const std::string _call_str("__call__"), _new_str("__new__"), _init_str("__init__");
 Box* runtimeCallInternal(Box* obj, CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, Box* arg2, Box* arg3,
                          Box** args) {
     // the 10M upper bound isn't a hard max, just almost certainly a bug
@@ -1546,8 +1624,11 @@ Box* runtimeCallInternal(Box* obj, CallRewriteArgs* rewrite_args, int64_t nargs,
             return rtn;
         }
 
-        if (cf->sig->is_vararg)
+        if (cf->sig->is_vararg) {
+            if (rewrite_args && VERBOSITY())
+                printf("Not patchpointing this varargs function\n");
             rewrite_args = NULL;
+        }
         if (cf->is_interpreted)
             rewrite_args = NULL;
 
@@ -2159,11 +2240,6 @@ static void assertInitNone(Box* obj) {
     }
 }
 
-// Wrapping the ctor to get a defined ABI for calling from an IC:
-static Box* makeUserObject(BoxedClass* cls) {
-    return new BoxedUserObject(cls);
-}
-
 Box* typeCallInternal(CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, Box* arg2, Box* arg3, Box** args) {
     static StatCounter slowpath_typecall("slowpath_typecall");
     slowpath_typecall.log();
@@ -2200,7 +2276,7 @@ Box* typeCallInternal(CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, B
     if (rewrite_args) {
         GetattrRewriteArgs grewrite_args(rewrite_args->rewriter, r_ccls);
         grewrite_args.preferred_dest_reg = -2;
-        new_attr = typeLookup(ccls, "__new__", &grewrite_args, NULL);
+        new_attr = typeLookup(ccls, _new_str, &grewrite_args, NULL);
 
         if (!grewrite_args.out_success)
             rewrite_args = NULL;
@@ -2211,12 +2287,13 @@ Box* typeCallInternal(CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, B
             }
         }
     } else {
-        new_attr = typeLookup(ccls, "__new__", NULL, NULL);
+        new_attr = typeLookup(ccls, _new_str, NULL, NULL);
     }
+    assert(new_attr && "This should always resolve");
 
     if (rewrite_args) {
         GetattrRewriteArgs grewrite_args(rewrite_args->rewriter, r_ccls);
-        init_attr = typeLookup(ccls, "__init__", &grewrite_args, NULL);
+        init_attr = typeLookup(ccls, _init_str, &grewrite_args, NULL);
 
         if (!grewrite_args.out_success)
             rewrite_args = NULL;
@@ -2227,97 +2304,71 @@ Box* typeCallInternal(CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, B
             }
         }
     } else {
-        init_attr = typeLookup(ccls, "__init__", NULL, NULL);
+        init_attr = typeLookup(ccls, _init_str, NULL, NULL);
     }
+    // The init_attr should always resolve as well, but doesn't yet
 
-    // Box* made = callattrInternal(ccls, &_new_str, INST_ONLY, NULL, nargs, cls, arg2, arg3, args);
     Box* made;
     RewriterVar r_made;
-    if (new_attr) {
-        if (rewrite_args) {
-            if (init_attr)
-                r_init.push();
-            if (nargs >= 1)
-                r_ccls.push();
-            if (nargs >= 2)
-                rewrite_args->arg2.push();
-            if (nargs >= 3)
-                rewrite_args->arg3.push();
-            if (nargs >= 4)
-                rewrite_args->args.push();
 
-            CallRewriteArgs srewrite_args(rewrite_args->rewriter, r_new);
-            if (nargs >= 1)
-                srewrite_args.arg1 = r_ccls;
-            if (nargs >= 2)
-                srewrite_args.arg2 = rewrite_args->arg2;
-            if (nargs >= 3)
-                srewrite_args.arg3 = rewrite_args->arg3;
-            if (nargs >= 4)
-                srewrite_args.args = rewrite_args->args;
-            srewrite_args.args_guarded = true;
-            srewrite_args.func_guarded = true;
-
-            r_new.push();
-
-            made = runtimeCallInternal(new_attr, &srewrite_args, nargs, cls, arg2, arg3, args);
+    if (rewrite_args) {
+        if (init_attr)
+            r_init.push();
+        if (nargs >= 1)
+            r_ccls.push();
+        if (nargs >= 2)
+            rewrite_args->arg2.push();
+        if (nargs >= 3)
+            rewrite_args->arg3.push();
+        if (nargs >= 4)
+            rewrite_args->args.push();
 
-            if (!srewrite_args.out_success)
-                rewrite_args = NULL;
-            else {
-                r_made = srewrite_args.out_rtn;
+        CallRewriteArgs srewrite_args(rewrite_args->rewriter, r_new);
+        if (nargs >= 1)
+            srewrite_args.arg1 = r_ccls;
+        if (nargs >= 2)
+            srewrite_args.arg2 = rewrite_args->arg2;
+        if (nargs >= 3)
+            srewrite_args.arg3 = rewrite_args->arg3;
+        if (nargs >= 4)
+            srewrite_args.args = rewrite_args->args;
+        srewrite_args.args_guarded = true;
+        srewrite_args.func_guarded = true;
 
-                r_new = rewrite_args->rewriter->pop(0);
-                r_made = r_made.move(-1);
+        r_new.push();
 
-                if (nargs >= 4)
-                    rewrite_args->args = rewrite_args->rewriter->pop(3);
-                if (nargs >= 3)
-                    rewrite_args->arg3 = rewrite_args->rewriter->pop(2);
-                if (nargs >= 2)
-                    rewrite_args->arg2 = rewrite_args->rewriter->pop(1);
-                if (nargs >= 1)
-                    r_ccls = rewrite_args->arg1 = rewrite_args->rewriter->pop(0);
-                if (init_attr)
-                    r_init = rewrite_args->rewriter->pop(-2);
+        int new_args = nargs;
+        if (nargs > 1 && new_attr == typeLookup(object_cls, _new_str, NULL, NULL)) {
+            if (init_attr == typeLookup(object_cls, _init_str, NULL, NULL)) {
+                raiseExcHelper(TypeError, "object.__new__() takes no parameters");
+            } else {
+                new_args = 1;
             }
-        } else {
-            made = runtimeCallInternal(new_attr, NULL, nargs, cls, arg2, arg3, args);
         }
-    } else {
-        if (isUserDefined(ccls)) {
-            made = new BoxedUserObject(ccls);
 
-            if (rewrite_args) {
-                if (init_attr)
-                    r_init.push();
-                if (nargs >= 1)
-                    r_ccls.push();
-                if (nargs >= 2)
-                    rewrite_args->arg2.push();
-                if (nargs >= 3)
-                    rewrite_args->arg3.push();
-                if (nargs >= 4)
-                    rewrite_args->args.push();
+        made = runtimeCallInternal(new_attr, &srewrite_args, new_args, cls, arg2, arg3, args);
 
-                r_ccls.move(0);
-                r_made = rewrite_args->rewriter->call((void*)&makeUserObject);
+        if (!srewrite_args.out_success)
+            rewrite_args = NULL;
+        else {
+            r_made = srewrite_args.out_rtn;
 
-                if (nargs >= 4)
-                    rewrite_args->args = rewrite_args->rewriter->pop(3);
-                if (nargs >= 3)
-                    rewrite_args->arg3 = rewrite_args->rewriter->pop(2);
-                if (nargs >= 2)
-                    rewrite_args->arg2 = rewrite_args->rewriter->pop(1);
-                if (nargs >= 1)
-                    r_ccls = rewrite_args->arg1 = rewrite_args->rewriter->pop(0);
-                if (init_attr)
-                    r_init = rewrite_args->rewriter->pop(-2);
-            }
-        } else {
-            fprintf(stderr, "no __new__ defined for %s!\n", getNameOfClass(ccls)->c_str());
-            abort();
+            r_new = rewrite_args->rewriter->pop(0);
+            r_made = r_made.move(-1);
+
+            if (nargs >= 4)
+                rewrite_args->args = rewrite_args->rewriter->pop(3);
+            if (nargs >= 3)
+                rewrite_args->arg3 = rewrite_args->rewriter->pop(2);
+            if (nargs >= 2)
+                rewrite_args->arg2 = rewrite_args->rewriter->pop(1);
+            if (nargs >= 1)
+                r_ccls = rewrite_args->arg1 = rewrite_args->rewriter->pop(0);
+            if (init_attr)
+                r_init = rewrite_args->rewriter->pop(-2);
         }
+    } else {
+        made = runtimeCallInternal(new_attr, NULL, nargs, cls, arg2, arg3, args);
     }
 
     assert(made);
@@ -2359,6 +2410,8 @@ Box* typeCallInternal(CallRewriteArgs* rewrite_args, int64_t nargs, Box* arg1, B
         }
         assertInitNone(initrtn);
     } else {
+        // TODO this shouldn't be reached
+        // assert(0 && "I don't think this should be reached");
         if (new_attr == NULL && nargs != 1) {
             raiseExcHelper(TypeError, "object.__new__() takes no parameters");
         }

src/runtime/objmodel.h

@@ -54,7 +54,6 @@ extern "C" Box* open2(Box* arg1, Box* arg2);
 extern "C" Box* compare(Box*, Box*, int);
 extern "C" BoxedInt* len(Box* obj);
 extern "C" void print(Box* obj);
-extern "C" void dump(Box* obj);
 // extern "C" Box* trap();
 extern "C" i64 unboxedLen(Box* obj);
 extern "C" Box* binop(Box* lhs, Box* rhs, int op_type);
@@ -69,6 +68,7 @@ extern "C" Box* import(const std::string* name);
 extern "C" void checkUnpackingLength(i64 expected, i64 given);
 extern "C" void assertNameDefined(bool b, const char* name);
 extern "C" void assertFail(BoxedModule* inModule, Box* msg);
+extern "C" bool isSubclass(BoxedClass* child, BoxedClass* parent);
 
 class BinopRewriteArgs;
 extern "C" Box* binopInternal(Box* lhs, Box* rhs, int op_type, bool inplace, BinopRewriteArgs* rewrite_args);
@@ -87,6 +87,9 @@ Box* compareInternal(Box* lhs, Box* rhs, int op_type, CompareRewriteArgs* rewrit
 Box* getattr_internal(Box* obj, const std::string& attr, bool check_cls, bool allow_custom,
                       GetattrRewriteArgs* rewrite_args, GetattrRewriteArgs2* rewrite_args2);
 
+Box* typeLookup(BoxedClass* cls, const std::string& attr, GetattrRewriteArgs* rewrite_args,
+                GetattrRewriteArgs2* rewrite_args2);
+
 extern "C" void raiseAttributeErrorStr(const char* typeName, const char* attr) __attribute__((__noreturn__));
 extern "C" void raiseAttributeError(Box* obj, const char* attr) __attribute__((__noreturn__));
 extern "C" void raiseNotIterableError(const char* typeName) __attribute__((__noreturn__));

src/runtime/set.cpp

@@ -176,7 +176,7 @@ using namespace pyston::set;
 void setupSet() {
     set_cls->giveAttr("__name__", boxStrConstant("set"));
 
-    set_iterator_cls = new BoxedClass(0, sizeof(BoxedSet), false);
+    set_iterator_cls = new BoxedClass(object_cls, 0, sizeof(BoxedSet), false);
     set_iterator_cls->giveAttr("__name__", boxStrConstant("setiterator"));
     set_iterator_cls->giveAttr("__hasnext__",
                                new BoxedFunction(boxRTFunction((void*)setiteratorHasnext, BOXED_BOOL, 1, false)));

src/runtime/str.cpp

@@ -524,7 +524,7 @@ Box* strCount2(BoxedString* self, Box* elt) {
 }
 
 void setupStr() {
-    str_iterator_cls = new BoxedClass(0, sizeof(BoxedString), false);
+    str_iterator_cls = new BoxedClass(object_cls, 0, sizeof(BoxedString), false);
     str_iterator_cls->giveAttr("__name__", boxStrConstant("striterator"));
     str_iterator_cls->giveAttr("__hasnext__",
                                new BoxedFunction(boxRTFunction((void*)BoxedStringIterator::hasnext, NULL, 1, false)));

src/runtime/types.cpp

@@ -204,9 +204,10 @@ extern "C" void conservativeGCHandler(GCVisitor* v, void* p) {
 }
 
 extern "C" {
-BoxedClass* type_cls, *none_cls, *bool_cls, *int_cls, *float_cls, *str_cls, *function_cls, *instancemethod_cls,
-    *list_cls, *slice_cls, *module_cls, *dict_cls, *tuple_cls, *file_cls, *member_cls;
+BoxedClass* object_cls, *type_cls, *none_cls, *bool_cls, *int_cls, *float_cls, *str_cls, *function_cls,
+    *instancemethod_cls, *list_cls, *slice_cls, *module_cls, *dict_cls, *tuple_cls, *file_cls, *member_cls;
 
+const ObjectFlavor object_flavor(&boxGCHandler, NULL);
 const ObjectFlavor type_flavor(&typeGCHandler, NULL);
 const ObjectFlavor none_flavor(&boxGCHandler, NULL);
 const ObjectFlavor bool_flavor(&boxGCHandler, NULL);
@@ -221,7 +222,6 @@ const ObjectFlavor module_flavor(&boxGCHandler, NULL);
 const ObjectFlavor dict_flavor(&dictGCHandler, NULL);
 const ObjectFlavor tuple_flavor(&tupleGCHandler, NULL);
 const ObjectFlavor file_flavor(&boxGCHandler, NULL);
-const ObjectFlavor user_flavor(&boxGCHandler, NULL);
 const ObjectFlavor member_flavor(&boxGCHandler, NULL);
 
 const AllocationKind untracked_kind(NULL, NULL);
@@ -229,14 +229,26 @@ const AllocationKind hc_kind(&hcGCHandler, NULL);
 const AllocationKind conservative_kind(&conservativeGCHandler, NULL);
 }
 
-extern "C" Box* createUserClass(std::string* name, BoxedModule* parent_module) {
-    BoxedClass* rtn = new BoxedClass(offsetof(BoxedUserObject, attrs), sizeof(BoxedUserObject), true);
-    rtn->giveAttr("__name__", boxString(*name));
+extern "C" Box* createUserClass(std::string* name, Box* _base, BoxedModule* parent_module) {
+    assert(_base);
+    assert(isSubclass(_base->cls, type_cls));
+    BoxedClass* base = static_cast<BoxedClass*>(_base);
+
+    BoxedClass* made;
+
+    if (base->instancesHaveAttrs()) {
+        made = new BoxedClass(base, base->attrs_offset, base->instance_size, true);
+    } else {
+        assert(base->instance_size % sizeof(void*) == 0);
+        made = new BoxedClass(base, base->instance_size, base->instance_size + sizeof(HCAttrs), true);
+    }
+
+    made->giveAttr("__name__", boxString(*name));
 
     Box* modname = parent_module->getattr("__name__", NULL, NULL);
-    rtn->giveAttr("__module__", modname);
+    made->giveAttr("__module__", modname);
 
-    return rtn;
+    return made;
 }
 
 extern "C" Box* boxInstanceMethod(Box* obj, Box* func) {
@@ -371,35 +383,67 @@ CLFunction* unboxRTFunction(Box* b) {
     return static_cast<BoxedFunction*>(b)->f;
 }
 
+Box* objectNew1(BoxedClass* cls) {
+    assert(cls->instance_size >= sizeof(Box));
+    void* mem = rt_alloc(cls->instance_size);
+
+    Box* rtn = ::new (mem) Box(&object_flavor, cls);
+    if (cls->attrs_offset) {
+        HCAttrs* attrs = rtn->getAttrs();
+        attrs = new ((void*)attrs) HCAttrs();
+    }
+    return rtn;
+}
+
+Box* objectNew(BoxedClass* cls, BoxedList* args) {
+    assert(isSubclass(cls->cls, type_cls));
+
+    if (args->size != 0) {
+        if (typeLookup(cls, "__init__", NULL, NULL) == NULL)
+            raiseExcHelper(TypeError, "object.__new__() takes no parameters");
+    }
+
+    return objectNew1(cls);
+}
+
 bool TRACK_ALLOCATIONS = false;
 void setupRuntime() {
     HiddenClass::getRoot();
 
-    type_cls = new BoxedClass(offsetof(BoxedClass, attrs), sizeof(BoxedClass), false);
+    object_cls = new BoxedClass(NULL, 0, sizeof(Box), false);
+    type_cls = new BoxedClass(object_cls, offsetof(BoxedClass, attrs), sizeof(BoxedClass), false);
     type_cls->cls = type_cls;
+    object_cls->cls = type_cls;
 
-    none_cls = new BoxedClass(0, sizeof(Box), false);
+    none_cls = new BoxedClass(object_cls, 0, sizeof(Box), false);
     None = new Box(&none_flavor, none_cls);
-    gc::registerStaticRootObj(None);
 
-    module_cls = new BoxedClass(offsetof(BoxedModule, attrs), sizeof(BoxedModule), false);
+    str_cls = new BoxedClass(object_cls, 0, sizeof(BoxedString), false);
+
+    // It wasn't safe to add __base__ attributes until object+type+str are set up, so do that now:
+    type_cls->giveAttr("__base__", object_cls);
+    str_cls->giveAttr("__base__", object_cls);
+    none_cls->giveAttr("__base__", object_cls);
+    object_cls->giveAttr("__base__", None);
+
+
+    module_cls = new BoxedClass(object_cls, offsetof(BoxedModule, attrs), sizeof(BoxedModule), false);
 
     // TODO it'd be nice to be able to do these in the respective setupType methods,
     // but those setup methods probably want access to these objects.
     // We could have a multi-stage setup process, but that seems overkill for now.
-    bool_cls = new BoxedClass(0, sizeof(BoxedBool), false);
-    int_cls = new BoxedClass(0, sizeof(BoxedInt), false);
-    float_cls = new BoxedClass(0, sizeof(BoxedFloat), false);
-    str_cls = new BoxedClass(0, sizeof(BoxedString), false);
-    function_cls = new BoxedClass(offsetof(BoxedFunction, attrs), sizeof(BoxedFunction), false);
-    instancemethod_cls = new BoxedClass(0, sizeof(BoxedInstanceMethod), false);
-    list_cls = new BoxedClass(0, sizeof(BoxedList), false);
-    slice_cls = new BoxedClass(0, sizeof(BoxedSlice), false);
-    dict_cls = new BoxedClass(0, sizeof(BoxedDict), false);
-    tuple_cls = new BoxedClass(0, sizeof(BoxedTuple), false);
-    file_cls = new BoxedClass(0, sizeof(BoxedFile), false);
-    set_cls = new BoxedClass(0, sizeof(BoxedSet), false);
-    member_cls = new BoxedClass(0, sizeof(BoxedMemberDescriptor), false);
+    bool_cls = new BoxedClass(object_cls, 0, sizeof(BoxedBool), false);
+    int_cls = new BoxedClass(object_cls, 0, sizeof(BoxedInt), false);
+    float_cls = new BoxedClass(object_cls, 0, sizeof(BoxedFloat), false);
+    function_cls = new BoxedClass(object_cls, offsetof(BoxedFunction, attrs), sizeof(BoxedFunction), false);
+    instancemethod_cls = new BoxedClass(object_cls, 0, sizeof(BoxedInstanceMethod), false);
+    list_cls = new BoxedClass(object_cls, 0, sizeof(BoxedList), false);
+    slice_cls = new BoxedClass(object_cls, 0, sizeof(BoxedSlice), false);
+    dict_cls = new BoxedClass(object_cls, 0, sizeof(BoxedDict), false);
+    tuple_cls = new BoxedClass(object_cls, 0, sizeof(BoxedTuple), false);
+    file_cls = new BoxedClass(object_cls, 0, sizeof(BoxedFile), false);
+    set_cls = new BoxedClass(object_cls, 0, sizeof(BoxedSet), false);
+    member_cls = new BoxedClass(object_cls, 0, sizeof(BoxedMemberDescriptor), false);
 
     STR = typeFromClass(str_cls);
     BOXED_INT = typeFromClass(int_cls);
@@ -413,6 +457,12 @@ void setupRuntime() {
     SET = typeFromClass(set_cls);
     BOXED_TUPLE = typeFromClass(tuple_cls);
 
+    object_cls->giveAttr("__name__", boxStrConstant("object"));
+    auto object_new = boxRTFunction((void*)objectNew1, NULL, 1, false);
+    addRTFunction(object_new, (void*)objectNew, NULL, 1, true);
+    object_cls->giveAttr("__new__", new BoxedFunction(object_new));
+    object_cls->freeze();
+
     type_cls->giveAttr("__name__", boxStrConstant("type"));
     type_cls->giveAttr("__call__", new BoxedFunction(boxRTFunction((void*)typeCall, NULL, 1, true)));
     type_cls->giveAttr("__new__", new BoxedFunction(boxRTFunction((void*)typeNew, NULL, 2, true)));

src/runtime/types.h

@@ -59,16 +59,14 @@ BoxedDict* getSysModulesDict();
 BoxedList* getSysPath();
 
 extern "C" {
-extern BoxedClass* type_cls, *bool_cls, *int_cls, *float_cls, *str_cls, *function_cls, *none_cls, *instancemethod_cls,
-    *list_cls, *slice_cls, *module_cls, *dict_cls, *tuple_cls, *file_cls, *xrange_cls, *member_cls;
+extern BoxedClass* object_cls, *type_cls, *bool_cls, *int_cls, *float_cls, *str_cls, *function_cls, *none_cls,
+    *instancemethod_cls, *list_cls, *slice_cls, *module_cls, *dict_cls, *tuple_cls, *file_cls, *xrange_cls, *member_cls;
 }
 extern "C" {
-extern const ObjectFlavor type_flavor, bool_flavor, int_flavor, float_flavor, str_flavor, function_flavor, none_flavor,
-    instancemethod_flavor, list_flavor, slice_flavor, module_flavor, dict_flavor, tuple_flavor, file_flavor,
-    xrange_flavor, member_flavor;
+extern const ObjectFlavor object_flavor, type_flavor, bool_flavor, int_flavor, float_flavor, str_flavor,
+    function_flavor, none_flavor, instancemethod_flavor, list_flavor, slice_flavor, module_flavor, dict_flavor,
+    tuple_flavor, file_flavor, xrange_flavor, member_flavor;
 }
-extern "C" { extern const ObjectFlavor user_flavor; }
-
 extern "C" { extern Box* None, *NotImplemented, *True, *False; }
 extern "C" {
 extern Box* repr_obj, *len_obj, *hash_obj, *range_obj, *abs_obj, *min_obj, *max_obj, *open_obj, *chr_obj, *ord_obj,
@@ -88,7 +86,7 @@ extern "C" void listAppendInternal(Box* self, Box* v);
 extern "C" void listAppendArrayInternal(Box* self, Box** v, int nelts);
 extern "C" Box* boxCLFunction(CLFunction* f);
 extern "C" CLFunction* unboxCLFunction(Box* b);
-extern "C" Box* createUserClass(std::string* name, BoxedModule* parent_module);
+extern "C" Box* createUserClass(std::string* name, Box* base, BoxedModule* parent_module);
 extern "C" double unboxFloat(Box* b);
 extern "C" Box* createDict();
 extern "C" Box* createList();
@@ -268,14 +266,6 @@ public:
     BoxedFunction(CLFunction* f);
 };
 
-// TODO hack
-class BoxedUserObject : public Box {
-public:
-    HCAttrs attrs;
-
-    BoxedUserObject(BoxedClass* cls) : Box(&user_flavor, cls) {}
-};
-
 class BoxedModule : public Box {
 public:
     HCAttrs attrs;

test/tests/class_noctor.py

-# expected: fail
-# - don't support object.__new__ yet
-
 # Regression test:
 # If the init function doesn't exist, shouldn't just silently ignore any args
 # that got passed

test/tests/exceptions_basic.py

@@ -28,3 +28,26 @@ except ZeroDivisionError, e:
     print e.message
     print str(e), repr(e)
     print e
+
+
+class MyException(Exception):
+    pass
+
+def catches(e):
+    try:
+        try:
+            raise e
+        except MyException:
+            return True
+    except:
+        return False
+print catches(Exception())
+print catches(AttributeError())
+print catches(MyException())
+
+def f():
+    try:
+        raise Exception()
+    except:
+        print True
+f()

test/tests/inheritance.py

+
+def f1():
+    class C(object):
+        pass
+
+    class D(C):
+        pass
+
+    C.a = 1
+    print D.a
+
+    for inst in [C(), D(), object()]:
+        for cls in [C, D, object]:
+            print isinstance(inst, cls)
+
+    print object.__base__
+    print C.__base__
+    print D.__base__
+    print type.__base__
+    print type(None).__base__
+
+    # Just make sure these exist:
+    repr(Exception.__base__)
+    repr(str.__base__)
+f1()
+
+def f2():
+    class B(object):
+        def wrapper(self, n):
+            self.foo(n)
+            self.foo(n)
+
+    class C(B):
+        def foo(self, n):
+            print n
+
+    c = C()
+    print c.wrapper(2)
+f2()

test/tests/object_new_arguments.py

+# object.__new__ doesn't complain if __init__ is overridden:
+
+class C1(object):
+    def __init__(self, a):
+        pass
+
+class C2(object):
+    pass
+
+print "Trying C1"
+object.__new__(C1, 1)
+
+print "Trying C2"
+object.__new__(C2, 1)

test/tests/patching_under.py

@@ -33,3 +33,28 @@ class C2(object):
 c = C2()
 call_f(c, 2)
 call_f(c, 2)
+
+
+
+
+n = 0
+
+def f():
+    C()
+
+def init(self):
+    pass
+
+class C(object):
+    def __new__(cls):
+        global n
+        n += 1
+
+        if n == 10:
+            C.__init__ = init
+            f()
+
+        return object.__new__(cls)
+
+for i in xrange(20):
+    f()