[dont merge] reference checking helper function

src/codegen/irgen/refcounts.cpp

@@ -174,6 +174,10 @@ void addDecrefs(llvm::Value* v, bool nullable, int num_refs, llvm::Instruction*
                                                      getConstantInt(num_refs, g.i64), "", decref_pt);
     new llvm::StoreInst(new_refcount, refcount_ptr, decref_pt);
 
+#ifdef Py_REF_DEBUG
+    llvm::CallInst::Create(g.funcs.checkRefs, {v}, "", decref_pt);
+#endif
+
     llvm::BasicBlock* cur_block = decref_pt->getParent();
     llvm::BasicBlock* continue_block = cur_block->splitBasicBlock(decref_pt);
     llvm::BasicBlock* dealloc_block

src/codegen/runtime_hooks.cpp

@@ -322,6 +322,7 @@ void initGlobalFuncs(GlobalState& g) {
     GET(caughtCapiException);
     GET(reraiseCapiExcAsCxx);
     GET(deopt);
+    GET(checkRefs);
 
     GET(div_float_float);
     GET(floordiv_float_float);

src/codegen/runtime_hooks.h

@@ -53,6 +53,7 @@ struct GlobalFuncs {
     llvm::Value* raise0, *raise0_capi, *raise3, *raise3_capi, *rawThrow;
     llvm::Value* PyErr_Fetch, *PyErr_NormalizeException, *PyErr_Restore, *caughtCapiException, *reraiseCapiExcAsCxx;
     llvm::Value* deopt;
+    llvm::Value* checkRefs;
 
     llvm::Value* div_float_float, *floordiv_float_float, *mod_float_float, *pow_float_float;
 

src/runtime/inline/link_forcer.cpp

@@ -136,6 +136,7 @@ void force() {
     FORCE(caughtCapiException);
     FORCE(reraiseCapiExcAsCxx);
     FORCE(deopt);
+    FORCE(checkRefs);
 
     FORCE(div_i64_i64);
     FORCE(mod_i64_i64);

src/runtime/objmodel.cpp

@@ -6894,4 +6894,8 @@ extern "C" void boxedLocalsDel(Box* boxedLocals, BoxedString* attr) {
     }
     d.erase(it);
 }
+
+extern "C" void checkRefs(Box* b) {
+    RELEASE_ASSERT(b->ob_refcnt >= 0, "%ld", b->ob_refcnt);
+}
 }

src/runtime/objmodel.h

@@ -229,5 +229,7 @@ extern "C" void delGlobal(Box* globals, BoxedString* name);
 extern "C" void boxedLocalsSet(Box* boxedLocals, BoxedString* attr, Box* val);
 extern "C" Box* boxedLocalsGet(Box* boxedLocals, BoxedString* attr, Box* globals);
 extern "C" void boxedLocalsDel(Box* boxedLocals, BoxedString* attr);
+
+extern "C" void checkRefs(Box* b);
 }
 #endif