From 218a4d4b30f320797121ad9900d48743da77a1b3 Mon Sep 17 00:00:00 2001 From: Andrew Kelley Date: Sat, 22 Dec 2018 23:06:30 -0500 Subject: comptime: ability to @ptrCast to an extern struct and read fields --- src/ir.cpp | 64 +++++++++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 49 insertions(+), 15 deletions(-) (limited to 'src/ir.cpp') diff --git a/src/ir.cpp b/src/ir.cpp index 028582f87f..83960f2eee 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -159,7 +159,7 @@ static ZigType *ir_resolve_atomic_operand_type(IrAnalyze *ira, IrInstruction *op static IrInstruction *ir_lval_wrap(IrBuilder *irb, Scope *scope, IrInstruction *value, LVal lval); static ZigType *adjust_ptr_align(CodeGen *g, ZigType *ptr_type, uint32_t new_align); static ZigType *adjust_slice_align(CodeGen *g, ZigType *slice_type, uint32_t new_align); -static void buf_read_value_bytes(CodeGen *codegen, uint8_t *buf, ConstExprValue *val); +static Error buf_read_value_bytes(IrAnalyze *ira, AstNode *source_node, uint8_t *buf, ConstExprValue *val); static void buf_write_value_bytes(CodeGen *codegen, uint8_t *buf, ConstExprValue *val); static Error ir_read_const_ptr(IrAnalyze *ira, AstNode *source_node, ConstExprValue *out_val, ConstExprValue *ptr_val); @@ -13725,7 +13725,8 @@ static Error ir_read_const_ptr(IrAnalyze *ira, AstNode *source_node, Buf buf = BUF_INIT; buf_resize(&buf, src_size); buf_write_value_bytes(ira->codegen, (uint8_t*)buf_ptr(&buf), pointee); - buf_read_value_bytes(ira->codegen, (uint8_t*)buf_ptr(&buf), out_val); + if ((err = buf_read_value_bytes(ira, source_node, (uint8_t*)buf_ptr(&buf), out_val))) + return err; return ErrorNone; } @@ -13759,7 +13760,8 @@ static Error ir_read_const_ptr(IrAnalyze *ira, AstNode *source_node, ConstExprValue *elem_val = &array_val->data.x_array.data.s_none.elements[elem_index + i]; buf_write_value_bytes(ira->codegen, (uint8_t*)buf_ptr(&buf) + (i * elem_size), elem_val); } - buf_read_value_bytes(ira->codegen, (uint8_t*)buf_ptr(&buf), out_val); + if ((err = buf_read_value_bytes(ira, source_node, (uint8_t*)buf_ptr(&buf), out_val))) + return err; return ErrorNone; } case ConstPtrSpecialBaseStruct: @@ -20077,7 +20079,8 @@ static void buf_write_value_bytes(CodeGen *codegen, uint8_t *buf, ConstExprValue zig_unreachable(); } -static void buf_read_value_bytes(CodeGen *codegen, uint8_t *buf, ConstExprValue *val) { +static Error buf_read_value_bytes(IrAnalyze *ira, AstNode *source_node, uint8_t *buf, ConstExprValue *val) { + Error err; assert(val->special == ConstValSpecialStatic); switch (val->type->id) { case ZigTypeIdInvalid: @@ -20094,30 +20097,60 @@ static void buf_read_value_bytes(CodeGen *codegen, uint8_t *buf, ConstExprValue case ZigTypeIdPromise: zig_unreachable(); case ZigTypeIdVoid: - return; + return ErrorNone; case ZigTypeIdBool: val->data.x_bool = (buf[0] != 0); - return; + return ErrorNone; case ZigTypeIdInt: bigint_read_twos_complement(&val->data.x_bigint, buf, val->type->data.integral.bit_count, - codegen->is_big_endian, val->type->data.integral.is_signed); - return; + ira->codegen->is_big_endian, val->type->data.integral.is_signed); + return ErrorNone; case ZigTypeIdFloat: - float_read_ieee597(val, buf, codegen->is_big_endian); - return; + float_read_ieee597(val, buf, ira->codegen->is_big_endian); + return ErrorNone; case ZigTypeIdPointer: { val->data.x_ptr.special = ConstPtrSpecialHardCodedAddr; BigInt bn; - bigint_read_twos_complement(&bn, buf, codegen->builtin_types.entry_usize->data.integral.bit_count, - codegen->is_big_endian, false); + bigint_read_twos_complement(&bn, buf, ira->codegen->builtin_types.entry_usize->data.integral.bit_count, + ira->codegen->is_big_endian, false); val->data.x_ptr.data.hard_coded_addr.addr = bigint_as_unsigned(&bn); - return; + return ErrorNone; } case ZigTypeIdArray: zig_panic("TODO buf_read_value_bytes array type"); case ZigTypeIdStruct: - zig_panic("TODO buf_read_value_bytes struct type"); + switch (val->type->data.structure.layout) { + case ContainerLayoutAuto: { + ErrorMsg *msg = ir_add_error_node(ira, source_node, + buf_sprintf("non-extern, non-packed struct '%s' cannot have its bytes reinterpreted", + buf_ptr(&val->type->name))); + add_error_note(ira->codegen, msg, val->type->data.structure.decl_node, + buf_sprintf("declared here")); + return ErrorSemanticAnalyzeFail; + } + case ContainerLayoutExtern: { + size_t src_field_count = val->type->data.structure.src_field_count; + val->data.x_struct.fields = create_const_vals(src_field_count); + for (size_t field_i = 0; field_i < src_field_count; field_i += 1) { + ConstExprValue *field_val = &val->data.x_struct.fields[field_i]; + field_val->special = ConstValSpecialStatic; + TypeStructField *type_field = &val->type->data.structure.fields[field_i]; + field_val->type = type_field->type_entry; + if (type_field->gen_index == SIZE_MAX) + continue; + size_t offset = LLVMOffsetOfElement(ira->codegen->target_data_ref, val->type->type_ref, + type_field->gen_index); + uint8_t *new_buf = buf + offset; + if ((err = buf_read_value_bytes(ira, source_node, new_buf, field_val))) + return err; + } + return ErrorNone; + } + case ContainerLayoutPacked: + zig_panic("TODO buf_read_value_bytes packed struct"); + } + zig_unreachable(); case ZigTypeIdOptional: zig_panic("TODO buf_read_value_bytes maybe type"); case ZigTypeIdErrorUnion: @@ -20220,7 +20253,8 @@ static IrInstruction *ir_analyze_instruction_bit_cast(IrAnalyze *ira, IrInstruct IrInstruction *result = ir_const(ira, &instruction->base, dest_type); uint8_t *buf = allocate_nonzero(src_size_bytes); buf_write_value_bytes(ira->codegen, buf, val); - buf_read_value_bytes(ira->codegen, buf, &result->value); + if ((err = buf_read_value_bytes(ira, instruction->base.source_node, buf, &result->value))) + return ira->codegen->invalid_instruction; return result; } -- cgit v1.2.3