Add initial support for Objective-C class implementation

1 files changed, 558 insertions, 33 deletions

diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 083a1d90e..23ad81847 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -1173,6 +1173,332 @@ gb_internal lbProcedure *lb_create_objc_names(lbModule *main_module) {
 	return p;
 }
 
+// TODO(harold): Move this out of here and into a more suitable place.
+// TODO(harold): Should not take an allocator, but always use temp, as we return string literals as well.
+String lb_get_objc_type_encoding(Type *t, gbAllocator allocator, isize pointer_depth = 0) {
+    // NOTE(harold): See https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html#//apple_ref/doc/uid/TP40008048-CH100
+
+    // NOTE(harold): Darwin targets are always 64-bit. Should we drop this and assume "q" always?
+    #define INT_SIZE_ENCODING (build_context.metrics.ptr_size == 4 ? "i" : "q")
+    switch (t->kind) {
+    case Type_Basic: {
+        switch (t->Basic.kind) {
+        case Basic_Invalid:
+            return str_lit("?");
+
+        case Basic_llvm_bool:
+        case Basic_bool:
+        case Basic_b8:
+            return str_lit("B");
+
+        case Basic_b16:
+            return str_lit("C");
+        case Basic_b32:
+            return str_lit("I");
+        case Basic_b64:
+            return str_lit("q");
+        case Basic_i8:
+            return str_lit("c");
+        case Basic_u8:
+            return str_lit("C");
+        case Basic_i16:
+        case Basic_i16le:
+        case Basic_i16be:
+            return str_lit("s");
+        case Basic_u16:
+        case Basic_u16le:
+        case Basic_u16be:
+            return str_lit("S");
+        case Basic_i32:
+        case Basic_i32le:
+        case Basic_i32be:
+            return str_lit("i");
+        case Basic_u32le:
+        case Basic_u32:
+        case Basic_u32be:
+            return str_lit("I");
+        case Basic_i64:
+        case Basic_i64le:
+        case Basic_i64be:
+            return str_lit("q");
+        case Basic_u64:
+        case Basic_u64le:
+        case Basic_u64be:
+            return str_lit("Q");
+        case Basic_i128:
+        case Basic_i128le:
+        case Basic_i128be:
+            return str_lit("t");
+        case Basic_u128:
+        case Basic_u128le:
+        case Basic_u128be:
+            return str_lit("T");
+        case Basic_rune:
+            return str_lit("I");
+        case Basic_f16:
+        case Basic_f16le:
+        case Basic_f16be:
+            return str_lit("s");    // @harold: Closest we've got?
+        case Basic_f32:
+        case Basic_f32le:
+        case Basic_f32be:
+            return str_lit("f");
+        case Basic_f64:
+        case Basic_f64le:
+        case Basic_f64be:
+            return str_lit("d");
+
+        // TODO(harold) These:
+        case Basic_complex32:
+        case Basic_complex64:
+        case Basic_complex128:
+        case Basic_quaternion64:
+        case Basic_quaternion128:
+        case Basic_quaternion256:
+                return str_lit("?");
+
+        case Basic_int:
+            return str_lit(INT_SIZE_ENCODING);
+        case Basic_uint:
+            return build_context.metrics.ptr_size == 4 ? str_lit("I") : str_lit("Q");
+        case Basic_uintptr:
+        case Basic_rawptr:
+            return str_lit("^v");
+
+        case Basic_string:
+            return build_context.metrics.ptr_size == 4 ? str_lit("{string=*i}") : str_lit("{string=*q}");
+
+        case Basic_cstring: return str_lit("*");
+        case Basic_any:     return str_lit("{any=^v^v");  // rawptr + ^Type_Info
+
+        case Basic_typeid:
+            GB_ASSERT(t->Basic.size == 8);
+            return str_lit("q");
+
+        // Untyped types
+        case Basic_UntypedBool:
+        case Basic_UntypedInteger:
+        case Basic_UntypedFloat:
+        case Basic_UntypedComplex:
+        case Basic_UntypedQuaternion:
+        case Basic_UntypedString:
+        case Basic_UntypedRune:
+        case Basic_UntypedNil:
+        case Basic_UntypedUninit:
+            GB_PANIC("Untyped types cannot be @encoded()");
+            return str_lit("?");
+        }
+        break;
+    }
+
+    case Type_Named:
+    case Type_Struct:
+    case Type_Union: {
+        Type* base = t;
+        if (base->kind == Type_Named) {
+            base = base_type(base);
+            if(base->kind != Type_Struct && base->kind != Type_Union) {
+                return lb_get_objc_type_encoding(base, allocator, pointer_depth);
+            }
+        }
+
+        const bool is_union = base->kind == Type_Union;
+        if (!is_union) {
+            // Check for objc_SEL
+            if (internal_check_is_assignable_to(base, t_objc_SEL)) {
+                return str_lit(":");
+            }
+
+            // Check for objc_Class
+            if (internal_check_is_assignable_to(base, t_objc_SEL)) {
+                return str_lit("#");
+            }
+
+            // Treat struct as an Objective-C Class?
+            if (has_type_got_objc_class_attribute(base) && pointer_depth == 0) {
+                return str_lit("#");
+            }
+        }
+
+        if (is_type_objc_object(base)) {
+            return str_lit("@");
+        }
+
+
+        gbString s = gb_string_make_reserve(allocator, 16);
+        s = gb_string_append_length(s, is_union ? "(" :"{", 1);
+        if (t->kind == Type_Named) {
+            s = gb_string_append_length(s, t->Named.name.text, t->Named.name.len);
+        }
+
+        // Write fields
+        if (pointer_depth < 2) {
+            s = gb_string_append_length(s, "=", 1);
+
+            if (!is_union) {
+                for( auto& f : t->Struct.fields ) {
+                    String field_type = lb_get_objc_type_encoding(f->type, allocator, pointer_depth);
+                    s = gb_string_append_length(s, field_type.text, field_type.len);
+                }
+            } else {
+                // #TODO(harold): Encode fields
+            }
+        }
+
+        s = gb_string_append_length(s, is_union ? ")" :"}", 1);
+
+        return make_string_c(s);
+    }
+
+    case Type_Generic:
+        GB_PANIC("Generic types cannot be @encoded()");
+        return str_lit("?");
+
+    case Type_Pointer: {
+        String pointee = lb_get_objc_type_encoding(t->Pointer.elem, allocator, pointer_depth +1);
+        // Special case for Objective-C Objects
+        if (pointer_depth == 0 && pointee == "@") {
+            return pointee;
+        }
+
+        return concatenate_strings(allocator, str_lit("^"), pointee);
+    }
+
+    case Type_MultiPointer:
+        return concatenate_strings(allocator, str_lit("^"), lb_get_objc_type_encoding(t->Pointer.elem, allocator, pointer_depth +1));
+
+    case Type_Array: {
+        String type_str = lb_get_objc_type_encoding(t->Array.elem, allocator, pointer_depth);
+
+        gbString s = gb_string_make_reserve(allocator, type_str.len + 8);
+        s = gb_string_append_fmt(s, "[%lld%s]", t->Array.count, type_str.text);
+        return make_string_c(s);
+    }
+
+    case Type_EnumeratedArray: {
+        String type_str = lb_get_objc_type_encoding(t->EnumeratedArray.elem, allocator, pointer_depth);
+
+        gbString s = gb_string_make_reserve(allocator, type_str.len + 8);
+        s = gb_string_append_fmt(s, "[%lld%s]", t->EnumeratedArray.count, type_str.text);
+        return make_string_c(s);
+    }
+
+    case Type_Slice: {
+        String type_str = lb_get_objc_type_encoding(t->Slice.elem, allocator, pointer_depth);
+        gbString s = gb_string_make_reserve(allocator, type_str.len + 8);
+        s = gb_string_append_fmt(s, "{slice=^%s%s}", type_str, INT_SIZE_ENCODING);
+        return make_string_c(s);
+    }
+
+    case Type_DynamicArray: {
+        String type_str = lb_get_objc_type_encoding(t->DynamicArray.elem, allocator, pointer_depth);
+        gbString s = gb_string_make_reserve(allocator, type_str.len + 8);
+        s = gb_string_append_fmt(s, "{dynamic=^%s%s%sAllocator={?^v}}", type_str, INT_SIZE_ENCODING, INT_SIZE_ENCODING);
+        return make_string_c(s);
+    }
+
+    case Type_Map:
+        return str_lit("{^v^v{Allocator=?^v}}");
+    case Type_Enum:
+        return lb_get_objc_type_encoding(t->Enum.base_type, allocator, pointer_depth);
+    case Type_Tuple:
+        // NOTE(harold): Is this allowed here?
+        return str_lit("?");
+    case Type_Proc:
+        return str_lit("?");
+    case Type_BitSet:
+        return lb_get_objc_type_encoding(t->BitSet.underlying, allocator, pointer_depth);
+    case Type_SimdVector:
+        break;
+    case Type_Matrix:
+        break;
+    case Type_BitField:
+        return lb_get_objc_type_encoding(t->BitField.backing_type, allocator, pointer_depth);
+    case Type_SoaPointer: {
+        gbString s = gb_string_make_reserve(allocator, 8);
+        s = gb_string_append_fmt(s, "{=^v%s}", INT_SIZE_ENCODING);
+        return make_string_c(s);
+    }
+
+    } // End switch t->kind
+    #undef INT_SIZE_ENCODING
+
+    GB_PANIC("Unreachable");
+}
+
+struct lbObjCGlobalClass {
+    lbObjCGlobal g;
+    lbValue      class_value;    // Local registered class value
+};
+
+gb_internal void lb_register_objc_thing(
+    StringSet &handled,
+    lbModule *m,
+    Array<lbValue> &args,
+    Array<lbObjCGlobalClass> &class_impls,
+    StringMap<lbObjCGlobalClass> &class_map,
+    lbProcedure *p,
+    lbObjCGlobal const &g,
+    char const *call
+) {
+    if (string_set_update(&handled, g.name)) {
+        return;
+    }
+
+    lbAddr addr = {};
+    lbValue *found = string_map_get(&m->members, g.global_name);
+    if (found) {
+        addr = lb_addr(*found);
+    } else {
+        lbValue v = {};
+        LLVMTypeRef t = lb_type(m, g.type);
+        v.value = LLVMAddGlobal(m->mod, t, g.global_name);
+        v.type = alloc_type_pointer(g.type);
+        addr = lb_addr(v);
+        LLVMSetInitializer(v.value, LLVMConstNull(t));
+    }
+
+    lbValue class_ptr{};
+    lbValue class_name = lb_const_value(m, t_cstring, exact_value_string(g.name));
+
+    // If this class requires an implementation, save it for registration below.
+    if (g.class_impl_type != nullptr) {
+
+        // Make sure the superclass has been initialized before us
+        lbValue superclass_value{};
+
+        auto& tn = g.class_impl_type->Named.type_name->TypeName;
+        Type *superclass = tn.objc_superclass;
+        if (superclass != nullptr) {
+            auto& superclass_global = string_map_must_get(&class_map, superclass->Named.type_name->TypeName.objc_class_name);
+            lb_register_objc_thing(handled, m, args, class_impls, class_map, p, superclass_global.g, call);
+            GB_ASSERT(superclass_global.class_value.value);
+
+            superclass_value = superclass_global.class_value;
+        }
+
+        args.count = 3;
+        args[0] = superclass == nullptr ? lb_const_nil(m, t_objc_Class) : superclass_value;
+        args[1] = class_name;
+        args[2] = lb_const_int(m, t_uint, 0);
+        class_ptr = lb_emit_runtime_call(p, "objc_allocateClassPair", args);
+
+        array_add(&class_impls, lbObjCGlobalClass{g, class_ptr});
+    }
+    else {
+        args.count = 1;
+        args[0] = class_name;
+        class_ptr = lb_emit_runtime_call(p, call, args);
+    }
+
+    lb_addr_store(p, addr, class_ptr);
+
+    lbObjCGlobalClass* class_global = string_map_get(&class_map, g.name);
+    if (class_global != nullptr) {
+        class_global->class_value = class_ptr;
+    }
+}
+
 gb_internal void lb_finalize_objc_names(lbGenerator *gen, lbProcedure *p) {
 	if (p == nullptr) {
 		return;
@@ -1186,39 +1512,238 @@ gb_internal void lb_finalize_objc_names(lbGenerator *gen, lbProcedure *p) {
 	string_set_init(&handled);
 	defer (string_set_destroy(&handled));
 
-	auto args = array_make<lbValue>(temporary_allocator(), 1);
-
-	LLVMSetLinkage(p->value, LLVMInternalLinkage);
-	lb_begin_procedure_body(p);
-
-	auto register_thing = [&handled, &m, &args](lbProcedure *p, lbObjCGlobal const &g, char const *call) {
-		if (!string_set_update(&handled, g.name)) {
-			lbAddr addr = {};
-			lbValue *found = string_map_get(&m->members, g.global_name);
-			if (found) {
-				addr = lb_addr(*found);
-			} else {
-				lbValue v = {};
-				LLVMTypeRef t = lb_type(m, g.type);
-				v.value = LLVMAddGlobal(m->mod, t, g.global_name);
-				v.type = alloc_type_pointer(g.type);
-				addr = lb_addr(v);
-				LLVMSetInitializer(v.value, LLVMConstNull(t));
-			}
-
-			args[0] = lb_const_value(m, t_cstring, exact_value_string(g.name));
-			lbValue ptr = lb_emit_runtime_call(p, call, args);
-			lb_addr_store(p, addr, ptr);
-		}
-	};
-
-	for (lbObjCGlobal g = {}; mpsc_dequeue(&gen->objc_classes, &g); /**/) {
-		register_thing(p, g, "objc_lookUpClass");
-	}
-
-	for (lbObjCGlobal g = {}; mpsc_dequeue(&gen->objc_selectors, &g); /**/) {
-		register_thing(p, g, "sel_registerName");
-	}
+	auto args        = array_make<lbValue>(temporary_allocator(), 3, 8);
+    auto class_impls = array_make<lbObjCGlobalClass>(temporary_allocator(), 0, 16);
+
+    // Ensure classes that have been implicitly referenced through
+    // the objc_superclass attribute have a global variable available for them.
+    TypeSet class_set{};
+    type_set_init(&class_set, gen->objc_classes.count+16);
+    defer (type_set_destroy(&class_set));
+
+    auto referenced_classes = array_make<lbObjCGlobal>(temporary_allocator());
+    for (lbObjCGlobal g = {}; mpsc_dequeue(&gen->objc_classes, &g); /**/) {
+        array_add( &referenced_classes, g);
+
+        Type *cls = g.class_impl_type;
+        while (cls) {
+            if (type_set_update(&class_set, cls)) {
+                break;
+            }
+            GB_ASSERT(cls->kind == Type_Named);
+
+            cls = cls->Named.type_name->TypeName.objc_superclass;
+        }
+    }
+
+    for (auto pair : class_set) {
+        auto& tn = pair.type->Named.type_name->TypeName;
+        Type *class_impl = !tn.objc_is_implementation ? nullptr : pair.type;
+        lb_handle_objc_find_or_register_class(p, tn.objc_class_name, class_impl);
+    }
+    for (lbObjCGlobal g = {}; mpsc_dequeue(&gen->objc_classes, &g); /**/) {
+        array_add( &referenced_classes, g );
+    }
+
+    // Add all class globals to a map so that we can look them up dynamically
+    // in order to resolve out-of-order because classes that are being implemented
+    // need their superclasses to have been registered before them.
+    StringMap<lbObjCGlobalClass> global_class_map{};
+    string_map_init(&global_class_map, (usize)gen->objc_classes.count);
+    defer (string_map_destroy(&global_class_map));
+
+    for (lbObjCGlobal g :referenced_classes) {
+        string_map_set(&global_class_map, g.name, lbObjCGlobalClass{g});
+    }
+
+    LLVMSetLinkage(p->value, LLVMInternalLinkage);
+    lb_begin_procedure_body(p);
+
+    // Register class globals, gathering classes that must be implemented
+    for (auto& kv : global_class_map) {
+        lb_register_objc_thing(handled, m, args, class_impls, global_class_map, p, kv.value.g, "objc_lookUpClass");
+    }
+
+    // Prefetch selectors for implemented methods so that they can also be registered.
+    for (const auto& cd : class_impls) {
+        auto& g = cd.g;
+        Type *class_type = g.class_impl_type;
+
+        Array<ObjcMethodData>* methods = map_get(&m->info->objc_method_implementations, class_type);
+        if (!methods) {
+            continue;
+        }
+
+        for (const ObjcMethodData& md : *methods) {
+            lb_handle_objc_find_or_register_selector(p, md.ac.objc_selector);
+        }
+    }
+
+    // Now we can register all referenced selectors
+    for (lbObjCGlobal g = {}; mpsc_dequeue(&gen->objc_selectors, &g); /**/) {
+        lb_register_objc_thing(handled, m, args, class_impls, global_class_map, p, g, "sel_registerName");
+    }
+
+
+    // Emit method wrapper implementations and registration
+    auto wrapper_args = array_make<Type *>(temporary_allocator(), 2, 8);
+
+    for (const auto& cd : class_impls) {
+        auto& g = cd.g;
+        Type *class_type = g.class_impl_type;
+
+        Array<ObjcMethodData>* methods = map_get(&m->info->objc_method_implementations, class_type);
+        if (!methods) {
+            continue;
+        }
+
+        Type *class_ptr_type = alloc_type_pointer(class_type);
+        lbValue class_value = cd.class_value;
+
+        for (const ObjcMethodData& md : *methods) {
+            GB_ASSERT( md.proc_entity->kind == Entity_Procedure);
+            Type *method_type = md.proc_entity->type;
+
+            String proc_name = make_string_c("__$objc_method::");
+            proc_name = concatenate_strings(temporary_allocator(), proc_name, g.name);
+            proc_name = concatenate_strings(temporary_allocator(), proc_name, str_lit("::"));
+            proc_name = concatenate_strings( permanent_allocator(), proc_name, md.ac.objc_name);
+
+            wrapper_args.count = 2;
+            wrapper_args[0] = md.ac.objc_is_class_method ? t_objc_Class : class_ptr_type;
+            wrapper_args[1] = t_objc_SEL;
+
+            auto method_param_count  = (isize)method_type->Proc.param_count;
+            i32  method_param_offset = 0;
+
+            // TODO(harold): Need to make sure (at checker stage) that the non-class method has the self parameter already.
+            //               (Maybe this is already accounted for?.)
+            if (!md.ac.objc_is_class_method) {
+                GB_ASSERT(method_param_count >= 1);
+                method_param_count -= 1;
+                method_param_offset = 1;
+            }
+
+            for (i32 i = 0; i < method_param_count; i++) {
+                array_add(&wrapper_args, method_type->Proc.params->Tuple.variables[method_param_offset+i]->type);
+            }
+
+            Type *wrapper_args_tuple = alloc_type_tuple_from_field_types(wrapper_args.data, wrapper_args.count, false, true);
+            Type *wrapper_proc_type = alloc_type_proc(nullptr, wrapper_args_tuple, (isize)wrapper_args_tuple->Tuple.variables.count, nullptr, 0, false, ProcCC_CDecl);
+
+            lbProcedure *wrapper_proc = lb_create_dummy_procedure(m, proc_name, wrapper_proc_type);
+            lb_add_attribute_to_proc(wrapper_proc->module, wrapper_proc->value, "nounwind");
+
+            // Emit the wrapper
+            LLVMSetLinkage(wrapper_proc->value, LLVMExternalLinkage);
+            lb_begin_procedure_body(wrapper_proc);
+            {
+                auto method_call_args = array_make<lbValue>(temporary_allocator(), method_param_count + (isize)method_param_offset);
+
+                if (!md.ac.objc_is_class_method) {
+                    method_call_args[0] = lbValue {
+                        wrapper_proc->raw_input_parameters[0],
+                        class_ptr_type,
+                    };
+                }
+
+                for (isize i = 0; i < method_param_count; i++) {
+                    method_call_args[i+method_param_offset] = lbValue {
+                        wrapper_proc->raw_input_parameters[i+2],
+                        method_type->Proc.params->Tuple.variables[i+method_param_offset]->type,
+                    };
+                }
+                lbValue method_proc_value = lb_find_procedure_value_from_entity(m, md.proc_entity);
+
+                // Call real procedure for method from here, passing the parameters expected, if any.
+                lb_emit_call(wrapper_proc, method_proc_value, method_call_args);
+            }
+            lb_end_procedure_body(wrapper_proc);
+
+
+            // Add the method to the class
+            String method_encoding = str_lit("v");
+            // TODO (harold): Checker must ensure that objc_methods have a single return value or none!
+            GB_ASSERT(method_type->Proc.result_count <= 1);
+            if (method_type->Proc.result_count != 0) {
+                method_encoding = lb_get_objc_type_encoding(method_type->Proc.results->Tuple.variables[0]->type, temporary_allocator());
+            }
+
+            if (!md.ac.objc_is_class_method) {
+                method_encoding = concatenate_strings(temporary_allocator(), method_encoding, str_lit("@:"));
+            } else {
+                method_encoding = concatenate_strings(temporary_allocator(), method_encoding, str_lit("#:"));
+            }
+
+            for (i32 i = method_param_offset; i < method_param_count; i++) {
+                Type *param_type = method_type->Proc.params->Tuple.variables[i]->type;
+                String param_encoding = lb_get_objc_type_encoding(param_type, temporary_allocator());
+
+                method_encoding = concatenate_strings(temporary_allocator(), method_encoding, param_encoding);
+            }
+
+            // Emit method registration
+            lbAddr* sel_address = string_map_get(&m->objc_selectors, md.ac.objc_selector);
+            GB_ASSERT(sel_address);
+            lbValue selector_value = lb_addr_load(p, *sel_address);
+
+            args.count = 4;
+            args[0] = class_value;    // Class
+            args[1] = selector_value; // SEL
+            args[2] = lbValue { wrapper_proc->value, wrapper_proc->type };
+            args[3] = lb_const_value(m, t_cstring, exact_value_string(method_encoding));
+
+            // TODO(harold): Emit check BOOL result and panic if false.
+            lb_emit_runtime_call(p, "class_addMethod", args);
+
+        } // End methods
+
+        // Add ivar if we have one
+        Type *ivar_type = class_type->Named.type_name->TypeName.objc_ivar;
+        if (ivar_type != nullptr) {
+            // Register a single ivar for this class
+            Type *ivar_base = ivar_type->Named.base;
+            // TODO(harold): No idea if I can use this, but I assume so?
+            const i64 size      = ivar_base->cached_size;
+            const i64 alignment = ivar_base->cached_align;
+            // TODO(harold): Checker: Alignment must be compatible with ivar rules. Or we should increase the alignment if needed.
+
+            String ivar_name  = str_lit("__$ivar");
+            String ivar_types = str_lit("{= }");
+            args.count = 5;
+            args[0] = class_value;
+            args[1] = lb_const_value(m, t_cstring, exact_value_string(ivar_name));
+            args[2] = lb_const_value(m, t_uint, exact_value_u64((u64)size));
+            args[3] = lb_const_value(m, t_u8, exact_value_u64((u64)alignment));
+            args[4] = lb_const_value(m, t_cstring, exact_value_string(ivar_types));
+            lb_emit_runtime_call(p, "class_addIvar", args);
+        }
+
+        // Complete the class registration
+        args.count = 1;
+        args[0] = class_value;
+        lb_emit_runtime_call(p, "objc_registerClassPair", args);
+
+        // If we have an ivar, store its offset globally for an intrinsic
+        // TODO(harold): Only do this for types that had ivar_get calls registered!
+        if (ivar_type != nullptr) {
+            args.count = 2;
+            args[0] = class_value;
+            args[1] = lb_const_value(m, t_cstring, exact_value_string(str_lit("__$ivar")));
+            lbValue ivar = lb_emit_runtime_call(p, "class_getInstanceVariable", args);
+
+            args.count = 1;
+            args[0] = ivar;
+            lbValue ivar_offset     = lb_emit_runtime_call(p, "ivar_getOffset", args);
+            lbValue ivar_offset_u32 = lb_emit_conv(p, ivar_offset, t_u32);
+
+            String class_name = class_type->Named.type_name->TypeName.objc_class_name;
+            // TODO(harold): Oops! This is wrong, that map is there to prevent re-entry.
+            //               Simply emit from referred ivars. For now use a single module only.
+            lbAddr ivar_addr = string_map_must_get(&m->objc_ivars, class_name);
+            lb_addr_store(p, ivar_addr, ivar_offset_u32);
+        }
+    }
 
 	lb_end_procedure_body(p);
 }