refcounting fixes

src/asm_writing/rewriter.cpp

@@ -1515,6 +1515,11 @@ void Rewriter::commitReturning(RewriterVar* var) {
     assert(var->vrefcount == 1);
     var->stealRef();
 
+    for (RewriterVar* arg : args) {
+        if (arg->reftype != RefType::UNKNOWN)
+            arg->decvref();
+    }
+
     addAction([=]() {
         if (LOG_IC_ASSEMBLY) assembler->comment("commitReturning");
         var->getInReg(getReturnDestination(), true /* allow_constant_in_reg */);
@@ -1531,6 +1536,11 @@ void Rewriter::commitReturningNonPython(RewriterVar* var) {
 
     assert(var->reftype == RefType::UNKNOWN);
 
+    for (RewriterVar* arg : args) {
+        if (arg->reftype != RefType::UNKNOWN)
+            arg->decvref();
+    }
+
     addAction([=]() {
         if (LOG_IC_ASSEMBLY) assembler->comment("commitReturning");
         var->getInReg(getReturnDestination(), true /* allow_constant_in_reg */);

src/codegen/ast_interpreter.cpp

@@ -1581,7 +1581,8 @@ Value ASTInterpreter::visit_str(AST_Str* node) {
     } else {
         RELEASE_ASSERT(0, "%d", node->str_type);
     }
-    return Value(o, jit ? jit->imm(o) : NULL);
+    Py_INCREF(o);
+    return Value(o, jit ? jit->imm(o)->setType(RefType::BORROWED) : NULL);
 }
 
 Value ASTInterpreter::visit_name(AST_Name* node) {

src/runtime/objmodel.cpp

@@ -2698,7 +2698,7 @@ extern "C" bool nonzero(Box* obj) {
 
     RewriterVar* r_obj = NULL;
     if (rewriter.get()) {
-        r_obj = rewriter->getArg(0);
+        r_obj = rewriter->getArg(0)->setType(RefType::BORROWED);
         r_obj->addAttrGuard(offsetof(Box, cls), (intptr_t)obj->cls);
     }
 
@@ -3317,15 +3317,17 @@ Box* _callattrEntry(Box* obj, BoxedString* attr, CallattrFlags flags, Box* arg1,
         // or this kind of thing is necessary in a lot more places
         // rewriter->getArg(3).addGuard(npassed_args);
 
-        CallattrRewriteArgs rewrite_args(rewriter.get(), rewriter->getArg(0), rewriter->getReturnDestination());
+        CallattrRewriteArgs rewrite_args(rewriter.get(), rewriter->getArg(0)->setType(RefType::BORROWED), rewriter->getReturnDestination());
         if (npassed_args >= 1)
-            rewrite_args.arg1 = rewriter->getArg(3);
+            rewrite_args.arg1 = rewriter->getArg(3)->setType(RefType::BORROWED);
         if (npassed_args >= 2)
-            rewrite_args.arg2 = rewriter->getArg(4);
+            rewrite_args.arg2 = rewriter->getArg(4)->setType(RefType::BORROWED);
         if (npassed_args >= 3)
-            rewrite_args.arg3 = rewriter->getArg(5);
-        if (npassed_args >= 4)
+            rewrite_args.arg3 = rewriter->getArg(5)->setType(RefType::BORROWED);
+        if (npassed_args >= 4) {
+            assert(0 && "hmm need to figure out vrefs for this");
             rewrite_args.args = rewriter->getArg(6);
+        }
         rtn = callattrInternal<S, REWRITABLE>(obj, attr, scope, &rewrite_args, argspec, arg1, arg2, arg3, args,
                                               keyword_names);
 
@@ -3343,7 +3345,7 @@ Box* _callattrEntry(Box* obj, BoxedString* attr, CallattrFlags flags, Box* arg1,
                 rewriter->commitReturning(rtn);
             } else if (return_convention == ReturnConvention::NO_RETURN && flags.null_on_nonexistent) {
                 assert(!rtn);
-                rewriter->commitReturning(rewriter->loadConst(0, rewriter->getReturnDestination()));
+                rewriter->commitReturningNonPython(rewriter->loadConst(0, rewriter->getReturnDestination()));
             }
         }
     } else {
@@ -4858,8 +4860,6 @@ extern "C" Box* binop(Box* lhs, Box* rhs, int op_type) {
         if (!rewrite_args.out_success) {
             rewriter.reset(NULL);
         } else {
-            rewriter->getArg(0)->decvref();
-            rewriter->getArg(1)->decvref();
             rewriter->commitReturning(rewrite_args.out_rtn);
         }
     } else {