Hi all I'm trying to add a new runtime function to return the Data Pointer of an array as a v8::NumberObject, so I can operate upon memory addresses in other JavaScript commands. I'm having trouble constructing and returning an object of type v8::internal::Object, since it seems like every operation always returns a Local/Handle.
I reached out to one of the developers (Jakob) separately, and they pointed me to the definition of v8::NumberObject::New <https://source.chromium.org/chromium/chromium/src/+/main:v8/src/api/api.cc;l=7636;drc=e14364652369744ed1a8b9c4a582f11833b35aff>. However, I'm unable to figure out the plumbing required to satisfy the compiler that what I'm returning from the runtime function is indeed a v8::internal::Object. I've shared what I've tried doing to troubleshoot, the error log (bolding the actual errors) and code snippet below. Best Pradyumna *What I've Tried* 1. Constructing v8::StringObjects, v8::NumberObjects, and v8::internal::Numbers,by plumbing together APIs from https://v8docs.nodesource.com/node-0.8/da/d56/classv8_1_1_number_object.html and other sites. 2. Reading the relevant pieces of https://v8.dev/docs/embed to understand what Local/Handle/Persistents are. 3. Searched for call sites of the NumberObject/StringObject/Number APIs on the GitHub, Google, and You search engines to see if others have tried to do something similar. It turns out not a lot of people outside of the v8 developers are editing v8 (at least publicly). 4. Read through numbers StackOverflow questions about construction v8::internal::objects, and manipulating Locals. 5. Searching for related keywords on this forum. *Error Log (for one of the attempts)* # autoninja -C out/arm64.optdebug d8 ninja: Entering directory `out/arm64.optdebug' [1/11] CXX obj/v8_base_without_compiler/runtime-test.o FAILED: obj/v8_base_without_compiler/runtime-test.o ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/v8_base_without_compiler/runtime-test.o.d -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DCR_XCODE_VERSION=1420 -DCR_CLANG_REVISION=\"llvmorg-16-init-17653-g39da55e8-2\" -DCOMPONENT_BUILD -DCR_LIBCXX_REVISION=59bae40d835ae4eabaddbef781f5e3b778dd7907 -D_LIBCPP_ENABLE_ASSERTIONS=1 -D_DEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DCPPGC_VERIFY_HEAP -DENABLE_DISASSEMBLER -DV8_TYPED_ARRAY_MAX_SIZE_IN_HEAP=64 -DOBJECT_PRINT -DVERIFY_HEAP -DV8_TRACE_MAPS -DV8_ENABLE_ALLOCATION_TIMEOUT -DV8_ENABLE_FORCE_SLOW_PATH -DV8_ENABLE_DOUBLE_CONST_STORE_CHECK -DV8_INTL_SUPPORT -DENABLE_HANDLE_ZAPPING -DV8_CODE_COMMENTS -DV8_ENABLE_DEBUG_CODE -DV8_ENABLE_HEAP_SNAPSHOT_VERIFY -DV8_SNAPSHOT_NATIVE_CODE_COUNTERS -DV8_USE_EXTERNAL_STARTUP_DATA -DV8_ATOMIC_OBJECT_FIELD_WRITES -DV8_ENABLE_LAZY_SOURCE_POSITIONS -DV8_SHARED_RO_HEAP -DV8_WIN64_UNWINDING_INFO -DV8_ENABLE_REGEXP_INTERPRETER_THREADED_DISPATCH -DV8_SHORT_BUILTIN_CALLS -DV8_EXTERNAL_CODE_SPACE -DV8_ENABLE_MAGLEV -DV8_ENABLE_TURBOFAN -DV8_ENABLE_SYSTEM_INSTRUMENTATION -DV8_ENABLE_WEBASSEMBLY -DV8_ALLOCATION_FOLDING -DV8_ALLOCATION_SITE_TRACKING -DV8_ADVANCED_BIGINT_ALGORITHMS -DV8_STATIC_ROOTS -DV8_USE_ZLIB -DV8_USE_LIBM_TRIG_FUNCTIONS -DV8_ENABLE_CHECKS -DV8_COMPRESS_POINTERS -DV8_COMPRESS_POINTERS_IN_SHARED_CAGE -DV8_31BIT_SMIS_ON_64BIT_ARCH -DV8_ENABLE_SANDBOX -DV8_DEPRECATION_WARNINGS -DV8_IMMINENT_DEPRECATION_WARNINGS -DCPPGC_CAGED_HEAP -DCPPGC_YOUNG_GENERATION -DCPPGC_POINTER_COMPRESSION -DCPPGC_SLIM_WRITE_BARRIER -DV8_TARGET_ARCH_ARM64 -DV8_HAVE_TARGET_OS -DV8_TARGET_OS_MACOS -DDEBUG -DV8_RUNTIME_CALL_STATS -DBUILDING_V8_SHARED -DUSING_V8_BASE_SHARED -DUSING_V8_PLATFORM_SHARED -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DUSE_CHROMIUM_ICU=1 -DU_ENABLE_TRACING=1 -DU_ENABLE_RESOURCE_TRACING=0 -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -I../.. -Igen -I../../buildtools/third_party/libc++ -I../../include -Igen/include -I../../third_party/icu/source/common -I../../third_party/icu/source/i18n -I../../third_party/zlib -Wall -Werror -Wextra -Wimplicit-fallthrough -Wextra-semi -Wunreachable-code-aggressive -Wthread-safety -Wunguarded-availability -Wno-missing-field-initializers -Wno-unused-parameter -Wno-psabi -Wloop-analysis -Wno-unneeded-internal-declaration -Wenum-compare-conditional -Wno-ignored-pragma-optimize -Wno-deprecated-builtins -Wno-bitfield-constant-conversion -Wshadow -fno-delete-null-pointer-checks -fno-ident -fno-strict-aliasing -fstack-protector-strong -fcolor-diagnostics -fmerge-all-constants -fcrash-diagnostics-dir=../../tools/clang/crashreports -mllvm -instcombine-lower-dbg-declare=0 -ffp-contract=off -fcomplete-member-pointers -arch arm64 -fno-global-isel -mno-outline -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -ffile-compilation-dir=. -no-canonical-prefixes -ftrivial-auto-var-init=pattern -fno-omit-frame-pointer -g2 -gdwarf-aranges -Xclang -debug-info-kind=limited -isysroot ../../../../../../Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.1.sdk -mmacos-version-min=10.13 -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -Wmissing-field-initializers -Wunreachable-code -Wctad-maybe-unsupported -Wno-shadow -Wshorten-64-to-32 -O0 -fvisibility=default -Wexit-time-destructors -Wno-undefined-bool-conversion -Wno-tautological-undefined-compare -std=c++20 -Wno-trigraphs -fno-exceptions -fno-rtti -nostdinc++ -isystem../../buildtools/third_party/libc++/trunk/include -isystem../../buildtools/third_party/libc++abi/trunk/include -c ../../src/runtime/runtime-test.cc -o obj/v8_base_without_compiler/runtime-test.o *../../src/runtime/runtime-test.cc:1160:57: error: cannot initialize a parameter of type 'Value *' with an rvalue of type 'Local<NumberObject> *'* return *(v8::internal::Object*)v8::NumberObject::Cast(&numberObjectLocal); ^~~~~~~~~~~~~~~~~~ *../../include/v8-primitive-object.h:25:46: note: passing argument to parameter 'value' here* V8_INLINE static NumberObject* Cast(Value* value) { ^ In file included from ../../src/runtime/runtime-test.cc:10: In file included from ../../include/v8-function.h:11: In file included from ../../include/v8-function-callback.h:8: *../../include/v8-local-handle.h:166:5: error: static assertion failed due to requirement 'std::is_base_of<v8::NumberObject, v8::Value>::value': type check* static_assert(std::is_base_of<T, S>::value, "type check"); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *../../src/runtime/runtime-test.cc:1159:43: note: in instantiation of function template specialization 'v8::Local<v8::NumberObject>::Local<v8::Value>' requested here* Local<NumberObject> numberObjectLocal = v8::NumberObject::New((v8::Isolate*)isolate, number); ^ 2 errors generated. ninja: build stopped: subcommand failed. Error! - V8 compilation finished with errors. *Code Snippet* RUNTIME_FUNCTION(Runtime_AddressOfArray) { SealHandleScope shs(isolate); StdoutStream os; MaybeObject maybe_object(*args.address_of_arg_at(0)); Object object = maybe_object.GetHeapObjectOrSmi(); void* data_pointer = JSTypedArray::cast(object).DataPtr(); os << "Data Pointer: " << data_pointer << std::endl; std::string data_pointer_string; std::ostringstream stream; stream << data_pointer_string; data_pointer_string = stream.str(); int number = stoi(data_pointer_string); *Local<NumberObject> numberObjectLocal = v8::NumberObject::New((v8::Isolate*)isolate, number); return *(v8::internal::Object*)v8::NumberObject::Cast(&numberObjectLocal);* } -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. 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