feat: custom objc runtime, msgSend, and HOTObject experiment

.clangd

@@ -0,0 +1,4 @@
+If:
+  PathMatch: .*\.h
+CompileFlags:
+  Add: [-x, objective-c]

CMakeLists.txt

@@ -34,6 +34,7 @@ set(SYSTEM_SERVICES
     init
     debug
     termosh
+    testOBJC
 )
 
 set(VOLUME_ROOT "${CMAKE_BINARY_DIR}/StartupVolume")

userspace/CMakeLists.txt

@@ -7,7 +7,9 @@ set(CMAKE_C_EXTENSIONS OFF)
 
 message(STATUS "Building termOS's userspace")
 
+add_subdirectory(libobjc)
 add_subdirectory(libterm)
 add_subdirectory(init)
 add_subdirectory(debug)
+add_subdirectory(testOBJC)
 add_subdirectory(termosh)

userspace/libobjc/CMakeLists.txt

@@ -0,0 +1,31 @@
+cmake_minimum_required(VERSION 3.16)
+project(libobjc LANGUAGES C ASM_NASM OBJC)
+
+set(USER_C_FLAGS
+    -ffreestanding
+    -fno-builtin
+    -nostdlib
+    -nostdinc
+    -fno-stack-protector
+    -fno-pic
+    -fno-pie
+    -m64
+    -mno-red-zone
+    -mcmodel=small
+    -O2
+)
+
+set(LIBOBJC_SOURCES
+    src/runtime.c
+    src/lookup.c
+    src/msgSend.asm
+    src/exceptions.c
+    src/HOTObject.m
+)
+
+add_library(objc STATIC ${LIBOBJC_SOURCES})
+
+target_compile_options(objc PRIVATE $<$<COMPILE_LANGUAGE:C>:${USER_C_FLAGS}>)
+
+target_include_directories(objc PUBLIC inc)
+target_link_libraries(objc PRIVATE term)

userspace/libobjc/inc/HOTObject.h

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2026 0xKarinyash
+
+#pragma once
+#include <Types.h>
+
+typedef struct OBJCClass  OBJCClass;
+typedef struct OBJCObject OBJCObject;
+
+typedef OBJCObject* id;
+typedef OBJCClass*  Class;
+
+@interface HOTObject {
+    Class classPointer; 
+}
+
++ (id)alloc;
+- (id)init;
+- (id)free;
+
+@end

userspace/libobjc/src/HOTObject.m

@@ -0,0 +1,20 @@
+#import <HOTObject.h>
+
+extern id OBJCAllocateInstance(Class class);
+extern void MemoryFree(void* pointer);
+
+@implementation HOTObject
++ (id)alloc {
+    return OBJCAllocateInstance((Class)self);
+}
+
+- (id)init {
+    return self;
+}
+
+- (id)free {
+    MemoryFree(self);
+    return (id)0;
+}
+
+@end

userspace/libobjc/src/exceptions.c

@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2026 0xKarinyash
+

userspace/libobjc/src/lookup.c

@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2026 0xKarinyash
+

userspace/libobjc/src/msgSend.asm

@@ -0,0 +1,59 @@
+; SPDX-License-Identifier: GPL-3.0-or-later
+; Copyright (c) 2026 0xKarinyash
+
+[bits 64]
+section .text
+global objc_msgSend
+
+; id objc_msgSend(id self, SEL _cmd, ...)
+; RDI = self, RSI = _cmd (pointer on OBJCSelector)
+
+objc_msgSend:
+    test rdi, rdi
+    jz .return_nil
+    mov rax, [rdi]
+
+.search_class:
+    ; OBJClass:
+    ; 0: metaClass, 8: parentClass, 16: name, 24: version, 32: info, 40: instanceSize, 48: methods
+    mov r10, [rax + 48] ; R10 = OBJCMethodList*
+
+.search_method_list:
+    test r10, r10
+    jz .go_to_parent
+    ; OBJCMethodList: 
+    ; 0: next, 8: methodCount, 12: padding, 16: methods[]
+    mov ecx, [r10 + 8] ; ECX = methodCount
+    test ecx, ecx
+    jz .next_list
+
+    lea r11, [r10 + 16] ; R11 start of methods[]
+
+.loop_methods:
+    ; OBJCMethod:
+    ; 0: selector, 8: types, 16: functionPointer
+    mov r8, [r11]
+    cmp r8, rsi
+    je .found
+    add r11, 24
+    loop .loop_methods
+
+.next_list:
+    mov r10, [r10] ; r10 = list->next
+    jmp .search_method_list
+
+.go_to_parent:
+    mov rax, [rax + 8]
+    test rax, rax
+    jnz .search_class
+ 
+    jmp .return_nil
+
+.found:
+    mov rax, [r11 + 16]
+    jmp rax
+
+.return_nil:
+    xor rax, rax
+    xor rdx, rdx
+    ret

userspace/libobjc/src/runtime.c

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2026 0xKarinyash
+
+#include <termOS.h>
+
+typedef struct OBJCSelector    OBJCSelector;
+typedef struct OBJCMethod      OBJCMethod;
+typedef struct OBJCMethodList  OBJCMethodList;
+typedef struct OBJCClass       OBJCClass;
+typedef struct OBJCObject      OBJCObject;
+typedef struct OBJCSymbolTable OBJCSymbolTable;
+typedef struct OBJCModule      OBJCModule;
+
+struct OBJCSelector {
+    const char* name;
+    const char* types;
+};
+
+struct OBJCMethod {
+    struct OBJCSelector* selector;
+    const char* types;
+    void* functionPointer; // pointer to function
+};
+
+struct OBJCMethodList {
+    struct OBJCMethodList* next;
+    Int32 methodCount;
+    struct OBJCMethod methods[];
+};
+
+struct OBJCClass {
+    OBJCClass* metaClass; // pointer to metaclass
+    OBJCClass* parentClass; // parent
+    const char* name;
+    Int64 version;
+    Int64 info;
+    Int64 instanceSize;
+    OBJCMethodList* methods;
+};
+
+struct OBJCObject {
+    OBJCClass* classPointer;
+};
+
+struct OBJCSymbolTable {
+    UInt32 selectorReferencesCount;
+    OBJCSelector* selectorReferences;
+    UInt16 classDefinitionCount;
+    UInt16 categoryDefinitionCount;
+    void* definitions[];
+};
+
+struct OBJCModule {
+    UInt64 version;
+    UInt64 size;
+    const char* name;
+    OBJCSymbolTable* symbolTable;
+};
+
+enum { 
+    kOBJCRuntimeMaxClasses = 256
+};
+
+static OBJCClass* _classTable[kOBJCRuntimeMaxClasses];
+static UInt32 _classCount = 0;
+
+static OBJCClass* sOBJCGetClass(const char* name) {
+    for (UInt32 i = 0; i < _classCount; i++) {
+        if (StringCompare(_classTable[i]->name, name) == 0) return _classTable[i];
+    }
+    return nullptr;
+} 
+
+static void sOBJCRegisterModule(OBJCModule* module) {
+    if (!module || !module->symbolTable) return;
+    OBJCSymbolTable* symbolTable = module->symbolTable;
+    for (UInt16 i = 0; i < symbolTable->classDefinitionCount; i++) {
+        OBJCClass* class = (OBJCClass*)symbolTable->definitions[i];
+        if (_classCount < kOBJCRuntimeMaxClasses) {
+            _classTable[_classCount++] = class;
+        }
+    }
+}
+
+// real
+
+extern void* __objc_module_list_start;
+extern void* __objc_module_list_end;
+
+OBJCClass* objc_getClass(const char* name) {
+    return sOBJCGetClass(name);
+}
+
+void __objc_exec_class(OBJCModule* module) {
+    sOBJCRegisterModule(module);
+}
+
+OBJCClass* objc_lookup_class(const char* name) {
+    return sOBJCGetClass(name);
+}
+
+void _objc_init_runtime() {
+    void** currentModule = &__objc_module_list_start;
+    while (currentModule < &__objc_module_list_end) {
+        if (*currentModule) __objc_exec_class((OBJCModule*)*currentModule);
+        currentModule++;
+    }
+}
+
+
+OBJCObject* OBJCAllocateInstance(OBJCClass* class) {
+    if (!class) return nullptr;
+
+    OBJCObject* instance = (OBJCObject*)MemoryAllocate(class->instanceSize);
+    if (instance) {
+        MemorySet(instance, 0, class->instanceSize);
+        instance->classPointer = class;
+    }
+    
+    return instance;
+}

userspace/libterm/CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.16)
-project(libterm LANGUAGES C ASM_NASM)
+project(libterm LANGUAGES C ASM_NASM OBJC)
 
 set(USER_C_FLAGS
     -ffreestanding
@@ -37,18 +37,36 @@ target_compile_options(term PRIVATE $<$<COMPILE_LANGUAGE:C>:${USER_C_FLAGS}>)
 target_include_directories(term PUBLIC inc)
 
 add_library(RuntimeEntryObject OBJECT src/RuntimeEntry.asm)
-target_compile_options(RuntimeEntryObject PRIVATE $<$<COMPILE_LANGUAGE:C>:${USER_C_FLAGS}>)
+add_library(ObjCRuntimeEntryObject OBJECT src/ObjCRuntimeEntry.asm)
 
 function(add_termos_executable NAME SOURCES)
+    set(HAS_OBJC FALSE)
+    foreach(SRC ${SOURCES})
+        get_filename_component(EXT ${SRC} EXT)
+        if(EXT STREQUAL ".m")
+            set(HAS_OBJC TRUE)
+            break()
+        endif()
+    endforeach()
+
     add_executable(${NAME} ${SOURCES})
     
-    target_sources(${NAME} PRIVATE $<TARGET_OBJECTS:RuntimeEntryObject>)
+    if(HAS_OBJC)
+        target_sources(${NAME} PRIVATE $<TARGET_OBJECTS:ObjCRuntimeEntryObject>)
+        target_compile_options(${NAME} PRIVATE $<$<COMPILE_LANGUAGE:OBJC>:-fobjc-runtime=gnustep -fblocks>)
+        target_link_options(${NAME} PRIVATE -T ${libterm_SOURCE_DIR}/linker/objc.ld)
+        target_link_libraries(${NAME} PRIVATE objc)
+    else()
+        target_sources(${NAME} PRIVATE $<TARGET_OBJECTS:RuntimeEntryObject>)
+    endif()
+    
+    target_compile_options(${NAME} PRIVATE 
+        $<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:OBJC>>:${USER_C_FLAGS}>
+    )
 
-    target_compile_options(${NAME} PRIVATE $<$<COMPILE_LANGUAGE:C>:${USER_C_FLAGS}>)
     target_link_libraries(${NAME} PRIVATE term)
-    
     target_link_options(${NAME} PRIVATE
-        -T ${libterm_SOURCE_DIR}/linker.ld
+        -T ${libterm_SOURCE_DIR}/linker/common.ld
         -nostdlib
         -static
     )

userspace/libterm/linker/objc.ld

@@ -0,0 +1,28 @@
+SECTIONS
+{
+    .objc_metadata : 
+    {
+        . = ALIGN(8);
+        __objc_runtime_start = .;
+        
+        KEEP(*(.objc_info))
+        __objc_module_list_start = .;
+        KEEP(*(.objc_module_info)) 
+        __objc_module_list_end = .;
+        KEEP(*(.objc_selectors))
+        KEEP(*(.objc_classes))
+        KEEP(*(.objc_category))
+        KEEP(*(.objc_class_refs))
+        KEEP(*(.objc_class_names))
+        KEEP(*(.objc_method_names))
+        KEEP(*(.objc_method_types))
+        KEEP(*(.objc_protocol_list))
+        KEEP(*(.objc_string_object))
+        KEEP(*(.objc_constant_string))
+        KEEP(*(.objc_data))
+        KEEP(*(.objc_list.*))
+        
+        __objc_runtime_end = .;
+    }
+}
+INSERT AFTER .data;

userspace/libterm/src/ObjCRuntimeEntry.asm

@@ -0,0 +1,18 @@
+; SPDX-License-Identifier: GPL-3.0-or-later
+; Copyright (c) 2026 0xKarinyash
+
+[bits 64]
+
+section .text
+global _start
+extern main
+extern OSServiceProcessExit
+extern _objc_init_runtime
+
+_start:
+    call _objc_init_runtime 
+
+    call main
+    
+    mov rdi, rax
+    call OSServiceProcessExit

userspace/testOBJC/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.20)
+project(termOSobjcdbg LANGUAGES OBJC)
+
+file(GLOB_RECURSE testOBJC_SOURCES "src/*.m")
+
+add_termos_executable(testOBJC "${testOBJC_SOURCES}")

userspace/testOBJC/src/main.m

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2026 0xKarinyash
+
+#import <termOS.h>
+#import <HOTObject.h>
+
+@interface Test : HOTObject 
+- (void)sayHi;
+@end
+
+@implementation Test
+- (void)sayHi {
+    ConsolePrint("meow");
+}
+@end
+
+int main() {
+    return 1;
+    Test *t = [[Test alloc] init];
+    [t sayHi];
+    return 0;
+}