diff --git a/src/all_types.hpp b/src/all_types.hpp index 9d41b86fa0..c671682363 100644 --- a/src/all_types.hpp +++ b/src/all_types.hpp @@ -583,6 +583,7 @@ enum CastOp { CastOpNumLitToConcrete, CastOpErrSet, CastOpBitCast, + CastOpPtrOfArrayToSlice, }; struct AstNodeFnCallExpr { diff --git a/src/codegen.cpp b/src/codegen.cpp index d156a8a178..fab2ad659e 100644 --- a/src/codegen.cpp +++ b/src/codegen.cpp @@ -2530,7 +2530,7 @@ static LLVMValueRef ir_render_cast(CodeGen *g, IrExecutable *executable, assert(wanted_type->data.structure.is_slice); assert(actual_type->id == TypeTableEntryIdArray); - TypeTableEntry *wanted_pointer_type = wanted_type->data.structure.fields[0].type_entry; + TypeTableEntry *wanted_pointer_type = wanted_type->data.structure.fields[slice_ptr_index].type_entry; TypeTableEntry *wanted_child_type = wanted_pointer_type->data.pointer.child_type; @@ -2576,6 +2576,29 @@ static LLVMValueRef ir_render_cast(CodeGen *g, IrExecutable *executable, return expr_val; case CastOpBitCast: return LLVMBuildBitCast(g->builder, expr_val, wanted_type->type_ref, ""); + case CastOpPtrOfArrayToSlice: { + assert(cast_instruction->tmp_ptr); + assert(actual_type->id == TypeTableEntryIdPointer); + TypeTableEntry *array_type = actual_type->data.pointer.child_type; + assert(array_type->id == TypeTableEntryIdArray); + + LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, cast_instruction->tmp_ptr, + slice_ptr_index, ""); + LLVMValueRef indices[] = { + LLVMConstNull(g->builtin_types.entry_usize->type_ref), + LLVMConstInt(g->builtin_types.entry_usize->type_ref, 0, false), + }; + LLVMValueRef slice_start_ptr = LLVMBuildInBoundsGEP(g->builder, expr_val, indices, 2, ""); + gen_store_untyped(g, slice_start_ptr, ptr_field_ptr, 0, false); + + LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, cast_instruction->tmp_ptr, + slice_len_index, ""); + LLVMValueRef len_value = LLVMConstInt(g->builtin_types.entry_usize->type_ref, + array_type->data.array.len, false); + gen_store_untyped(g, len_value, len_field_ptr, 0, false); + + return cast_instruction->tmp_ptr; + } } zig_unreachable(); } @@ -3815,7 +3838,6 @@ static LLVMValueRef ir_render_slice(CodeGen *g, IrExecutable *executable, IrInst } else { end_val = LLVMConstInt(g->builtin_types.entry_usize->type_ref, array_type->data.array.len, false); } - if (want_runtime_safety) { add_bounds_check(g, start_val, LLVMIntEQ, nullptr, LLVMIntULE, end_val); if (instruction->end) { diff --git a/src/ir.cpp b/src/ir.cpp index 3c9adab796..cc4ffb44a9 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -108,6 +108,7 @@ static IrInstruction *ir_get_var_ptr(IrAnalyze *ira, IrInstruction *instruction, static TypeTableEntry *ir_resolve_atomic_operand_type(IrAnalyze *ira, IrInstruction *op); static IrInstruction *ir_lval_wrap(IrBuilder *irb, Scope *scope, IrInstruction *value, LVal lval); static TypeTableEntry *adjust_ptr_align(CodeGen *g, TypeTableEntry *ptr_type, uint32_t new_align); +static TypeTableEntry *adjust_slice_align(CodeGen *g, TypeTableEntry *slice_type, uint32_t new_align); ConstExprValue *const_ptr_pointee(CodeGen *g, ConstExprValue *const_val) { assert(const_val->type->id == TypeTableEntryIdPointer); @@ -8024,6 +8025,33 @@ static ImplicitCastMatchResult ir_types_match_with_implicit_cast(IrAnalyze *ira, } } + // implicit *[N]T to [*]T + if (expected_type->id == TypeTableEntryIdPointer && + expected_type->data.pointer.ptr_len == PtrLenUnknown && + actual_type->id == TypeTableEntryIdPointer && + actual_type->data.pointer.ptr_len == PtrLenSingle && + actual_type->data.pointer.child_type->id == TypeTableEntryIdArray && + types_match_const_cast_only(ira, expected_type->data.pointer.child_type, + actual_type->data.pointer.child_type->data.array.child_type, source_node).id == ConstCastResultIdOk) + { + return ImplicitCastMatchResultYes; + } + + // implicit *[N]T to []T + if (is_slice(expected_type) && + actual_type->id == TypeTableEntryIdPointer && + actual_type->data.pointer.ptr_len == PtrLenSingle && + actual_type->data.pointer.child_type->id == TypeTableEntryIdArray) + { + TypeTableEntry *slice_ptr_type = expected_type->data.structure.fields[slice_ptr_index].type_entry; + assert(slice_ptr_type->id == TypeTableEntryIdPointer); + if (types_match_const_cast_only(ira, slice_ptr_type->data.pointer.child_type, + actual_type->data.pointer.child_type->data.array.child_type, source_node).id == ConstCastResultIdOk) + { + return ImplicitCastMatchResultYes; + } + } + // implicit [N]T to ?[]const T if (expected_type->id == TypeTableEntryIdMaybe && is_slice(expected_type->data.maybe.child_type) && @@ -8699,6 +8727,7 @@ static void eval_const_expr_implicit_cast(CastOp cast_op, zig_unreachable(); case CastOpErrSet: case CastOpBitCast: + case CastOpPtrOfArrayToSlice: zig_panic("TODO"); case CastOpNoop: { @@ -8786,6 +8815,63 @@ static IrInstruction *ir_resolve_cast(IrAnalyze *ira, IrInstruction *source_inst } } +static IrInstruction *ir_resolve_ptr_of_array_to_unknown_len_ptr(IrAnalyze *ira, IrInstruction *source_instr, + IrInstruction *value, TypeTableEntry *wanted_type) +{ + assert(value->value.type->id == TypeTableEntryIdPointer); + wanted_type = adjust_ptr_align(ira->codegen, wanted_type, value->value.type->data.pointer.alignment); + + if (instr_is_comptime(value)) { + ConstExprValue *pointee = const_ptr_pointee(ira->codegen, &value->value); + if (pointee->special != ConstValSpecialRuntime) { + IrInstruction *result = ir_create_const(&ira->new_irb, source_instr->scope, + source_instr->source_node, wanted_type); + result->value.type = wanted_type; + result->value.data.x_ptr.special = ConstPtrSpecialBaseArray; + result->value.data.x_ptr.mut = value->value.data.x_ptr.mut; + result->value.data.x_ptr.data.base_array.array_val = pointee; + result->value.data.x_ptr.data.base_array.elem_index = 0; + result->value.data.x_ptr.data.base_array.is_cstr = false; + return result; + } + } + + IrInstruction *result = ir_build_cast(&ira->new_irb, source_instr->scope, source_instr->source_node, + wanted_type, value, CastOpBitCast); + result->value.type = wanted_type; + return result; +} + +static IrInstruction *ir_resolve_ptr_of_array_to_slice(IrAnalyze *ira, IrInstruction *source_instr, + IrInstruction *value, TypeTableEntry *wanted_type) +{ + wanted_type = adjust_slice_align(ira->codegen, wanted_type, value->value.type->data.pointer.alignment); + + if (instr_is_comptime(value)) { + ConstExprValue *pointee = const_ptr_pointee(ira->codegen, &value->value); + if (pointee->special != ConstValSpecialRuntime) { + assert(value->value.type->id == TypeTableEntryIdPointer); + TypeTableEntry *array_type = value->value.type->data.pointer.child_type; + assert(is_slice(wanted_type)); + bool is_const = wanted_type->data.structure.fields[slice_ptr_index].type_entry->data.pointer.is_const; + + IrInstruction *result = ir_create_const(&ira->new_irb, source_instr->scope, + source_instr->source_node, wanted_type); + init_const_slice(ira->codegen, &result->value, pointee, 0, array_type->data.array.len, is_const); + result->value.data.x_struct.fields[slice_ptr_index].data.x_ptr.mut = + value->value.data.x_ptr.mut; + result->value.type = wanted_type; + return result; + } + } + + IrInstruction *result = ir_build_cast(&ira->new_irb, source_instr->scope, source_instr->source_node, + wanted_type, value, CastOpPtrOfArrayToSlice); + result->value.type = wanted_type; + ir_add_alloca(ira, result, wanted_type); + return result; +} + static bool is_container(TypeTableEntry *type) { return type->id == TypeTableEntryIdStruct || type->id == TypeTableEntryIdEnum || @@ -9937,6 +10023,35 @@ static IrInstruction *ir_analyze_cast(IrAnalyze *ira, IrInstruction *source_inst } } + // explicit *[N]T to [*]T + if (wanted_type->id == TypeTableEntryIdPointer && + wanted_type->data.pointer.ptr_len == PtrLenUnknown && + actual_type->id == TypeTableEntryIdPointer && + actual_type->data.pointer.ptr_len == PtrLenSingle && + actual_type->data.pointer.child_type->id == TypeTableEntryIdArray && + actual_type->data.pointer.alignment >= wanted_type->data.pointer.alignment && + types_match_const_cast_only(ira, wanted_type->data.pointer.child_type, + actual_type->data.pointer.child_type->data.array.child_type, source_node).id == ConstCastResultIdOk) + { + return ir_resolve_ptr_of_array_to_unknown_len_ptr(ira, source_instr, value, wanted_type); + } + + // explicit *[N]T to []T + if (is_slice(wanted_type) && + actual_type->id == TypeTableEntryIdPointer && + actual_type->data.pointer.ptr_len == PtrLenSingle && + actual_type->data.pointer.child_type->id == TypeTableEntryIdArray) + { + TypeTableEntry *slice_ptr_type = wanted_type->data.structure.fields[slice_ptr_index].type_entry; + assert(slice_ptr_type->id == TypeTableEntryIdPointer); + if (types_match_const_cast_only(ira, slice_ptr_type->data.pointer.child_type, + actual_type->data.pointer.child_type->data.array.child_type, source_node).id == ConstCastResultIdOk) + { + return ir_resolve_ptr_of_array_to_slice(ira, source_instr, value, wanted_type); + } + } + + // explicit cast from child type of maybe type to maybe type if (wanted_type->id == TypeTableEntryIdMaybe) { TypeTableEntry *wanted_child_type = wanted_type->data.maybe.child_type; @@ -13150,6 +13265,13 @@ static TypeTableEntry *adjust_ptr_align(CodeGen *g, TypeTableEntry *ptr_type, ui ptr_type->data.pointer.bit_offset, ptr_type->data.pointer.unaligned_bit_count); } +static TypeTableEntry *adjust_slice_align(CodeGen *g, TypeTableEntry *slice_type, uint32_t new_align) { + assert(is_slice(slice_type)); + TypeTableEntry *ptr_type = adjust_ptr_align(g, slice_type->data.structure.fields[slice_ptr_index].type_entry, + new_align); + return get_slice_type(g, ptr_type); +} + static TypeTableEntry *adjust_ptr_len(CodeGen *g, TypeTableEntry *ptr_type, PtrLen ptr_len) { assert(ptr_type->id == TypeTableEntryIdPointer); return get_pointer_to_type_extra(g, diff --git a/test/cases/cast.zig b/test/cases/cast.zig index 7358a4ffd8..c3ef24cd78 100644 --- a/test/cases/cast.zig +++ b/test/cases/cast.zig @@ -384,3 +384,19 @@ test "const slice widen cast" { assert(@bitCast(u32, bytes) == 0x12121212); } + +test "single-item pointer of array to slice and to unknown length pointer" { + testCastPtrOfArrayToSliceAndPtr(); + comptime testCastPtrOfArrayToSliceAndPtr(); +} + +fn testCastPtrOfArrayToSliceAndPtr() void { + var array = "ao" ++ "eu"; // TODO https://github.com/ziglang/zig/issues/1076 + const x: [*]u8 = &array; + x[0] += 1; + assert(mem.eql(u8, array[0..], "boeu")); + const y: []u8 = &array; + y[0] += 1; + assert(mem.eql(u8, array[0..], "coeu")); +} +