Files
carbon-lang/toolchain/check/testdata/interop/cpp/enum/incomplete.carbon
T
Geoff RomerandRichard Smith e023f75254 Implement thunking in terms of constant evaluation (#7332)
The bulk of this change is changing most pattern insts to be `Always`
rather than `AlwaysUnique` constants, so that they can be wrapped in
`SpecificConstant`s to perform substitution. That then lets thunking
rely much more on `SpecificConstant` wrappers instead of deep-copying
the inst tree with modified types.

This approach to thunking should scale better, particularly as things
like form generics make function signatures more complex, because we can
leverage the existing support for constant evaluation and substitution.
Unfortunately, applying this approach to binding patterns will require
more work; see the TODO near the top of `thunk.cpp` for details.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-06-13 00:22:00 +00:00

95 lines
4.4 KiB
Plaintext

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/convert.carbon
// EXTRA-ARGS: --clang-arg=-fms-compatibility
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/enum/incomplete.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/enum/incomplete.carbon
// --- declaration.h
// This is not valid in standard C++, but MSVC allows it as an extension, and so
// Clang allows it in MSVC compatibility mode.
enum UnsizedEnum;
// --- import_declaration.carbon
library "[[@TEST_NAME]]";
// CHECK:STDERR: import_declaration.carbon:[[@LINE+5]]:10: in file included here [InCppInclude]
// CHECK:STDERR: ./declaration.h:4:6: warning: forward references to 'enum' types are a Microsoft extension [CppInteropParseWarning]
// CHECK:STDERR: 4 | enum UnsizedEnum;
// CHECK:STDERR: | ^
// CHECK:STDERR:
import Cpp library "declaration.h";
//@dump-sem-ir-begin
fn F(e: Cpp.UnsizedEnum);
//@dump-sem-ir-end
// --- fail_use_declaration_as_definition.carbon
library "[[@TEST_NAME]]";
// CHECK:STDERR: fail_use_declaration_as_definition.carbon:[[@LINE+5]]:10: in file included here [InCppInclude]
// CHECK:STDERR: ./declaration.h:4:6: warning: forward references to 'enum' types are a Microsoft extension [CppInteropParseWarning]
// CHECK:STDERR: 4 | enum UnsizedEnum;
// CHECK:STDERR: | ^
// CHECK:STDERR:
import Cpp library "declaration.h";
fn MyF() {
// TODO: It's a bit surprising to refer to this type as a class, even though
// we model it as a class in Carbon. Consider customizing the diagnostic.
// CHECK:STDERR: fail_use_declaration_as_definition.carbon:[[@LINE+8]]:17: error: binding pattern has incomplete type `UnsizedEnum` in name binding declaration [IncompleteTypeInBindingDecl]
// CHECK:STDERR: var unused e: Cpp.UnsizedEnum;
// CHECK:STDERR: ^~~~~~~~~~~~~~~
// CHECK:STDERR: fail_use_declaration_as_definition.carbon:[[@LINE-8]]:10: in file included here [InCppInclude]
// CHECK:STDERR: ./declaration.h:4:6: note: class was forward declared here [ClassForwardDeclaredHere]
// CHECK:STDERR: enum UnsizedEnum;
// CHECK:STDERR: ^
// CHECK:STDERR:
var unused e: Cpp.UnsizedEnum;
}
// CHECK:STDOUT: --- import_declaration.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %UnsizedEnum: type = class_type @UnsizedEnum [concrete]
// CHECK:STDOUT: %pattern_type: type = pattern_type %UnsizedEnum [concrete]
// CHECK:STDOUT: %e.param_patt: %pattern_type = value_param_pattern [concrete]
// CHECK:STDOUT: %e.patt: %pattern_type = at_binding_pattern e, %e.param_patt [concrete]
// CHECK:STDOUT: %F.type: type = fn_type @F [concrete]
// CHECK:STDOUT: %F: %F.type = struct_value () [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .UnsizedEnum = %UnsizedEnum.decl
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %UnsizedEnum.decl: type = class_decl @UnsizedEnum [concrete = constants.%UnsizedEnum] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT: %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {
// CHECK:STDOUT: %e.param_patt: %pattern_type = value_param_pattern [concrete = constants.%e.param_patt]
// CHECK:STDOUT: %e.patt: %pattern_type = at_binding_pattern e, %e.param_patt [concrete = constants.%e.patt]
// CHECK:STDOUT: } {
// CHECK:STDOUT: %e.param: %UnsizedEnum = value_param call_param0
// CHECK:STDOUT: %.loc12: type = splice_block %UnsizedEnum.ref [concrete = constants.%UnsizedEnum] {
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %UnsizedEnum.ref: type = name_ref UnsizedEnum, imports.%UnsizedEnum.decl [concrete = constants.%UnsizedEnum]
// CHECK:STDOUT: }
// CHECK:STDOUT: %e: %UnsizedEnum = value_binding e, %e.param
// CHECK:STDOUT: }
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F(%e.param: %UnsizedEnum);
// CHECK:STDOUT: