From 9d84391f11fbcc6211cb3fcbac8dbfb95bb4fd0e Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Tue, 16 Sep 2025 16:39:07 -0700 Subject: [PATCH] Support for passing pointers to function templates. (#6080) When a function template takes a parameter of deduced type, and we deduce that type to a pointer type because we passed a Carbon pointer as the argument, don't complain that the deduced type is not nullable. We still know that it can't be null, because we deduced it from a non-nullable type. --- toolchain/check/cpp_import.cpp | 8 +- .../interop/cpp/function/pointer.carbon | 222 ++++++++++++++++++ 2 files changed, 228 insertions(+), 2 deletions(-) diff --git a/toolchain/check/cpp_import.cpp b/toolchain/check/cpp_import.cpp index cf995890863b..e939ea3b5da1 100644 --- a/toolchain/check/cpp_import.cpp +++ b/toolchain/check/cpp_import.cpp @@ -1255,8 +1255,12 @@ static auto MapPointerType(Context& context, clang::QualType type, if (auto nullability = type->getNullability(); !nullability.has_value() || *nullability != clang::NullabilityKind::NonNull) { - // TODO: Support nullable pointers. - return TypeExpr::None; + // If the type was produced by C++ template substitution, then we assume it + // was deduced from a Carbon pointer type, so it's non-null. + if (!type->getAs()) { + // TODO: Support nullable pointers. + return TypeExpr::None; + } } SemIR::TypeId pointer_type_id = diff --git a/toolchain/check/testdata/interop/cpp/function/pointer.carbon b/toolchain/check/testdata/interop/cpp/function/pointer.carbon index e6d8f016d991..32a84696fd87 100644 --- a/toolchain/check/testdata/interop/cpp/function/pointer.carbon +++ b/toolchain/check/testdata/interop/cpp/function/pointer.carbon @@ -187,6 +187,75 @@ fn F() { //@dump-sem-ir-end } +// ============================================================================ +// Deduced pointer type as template argument +// ============================================================================ + +// --- deduced_any_param.h + +struct S {}; + +template +auto foo(T) -> T; + +// --- import_deduced_any_param_as_pointer.carbon + +library "[[@TEST_NAME]]"; + +import Cpp library "deduced_any_param.h"; + +fn F() { + //@dump-sem-ir-begin + var s: Cpp.S = {}; + let p: Cpp.S* = Cpp.foo(&s); + //@dump-sem-ir-end +} + +// --- deduced_pointer_param.h + +struct S {}; + +template +auto Direct(T*) -> T*; + +template +using Wrap = T; + +template +using AddPointer = Wrap; + +template +auto Indirect(V) -> AddPointer; + +// --- fail_import_deduced_pointer_param_as_pointer.carbon + +library "[[@TEST_NAME]]"; + +import Cpp library "deduced_pointer_param.h"; + +fn F() { + //@dump-sem-ir-begin + var s: Cpp.S = {}; + // CHECK:STDERR: fail_import_deduced_pointer_param_as_pointer.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: parameter type: struct S *` [SemanticsTodo] + // CHECK:STDERR: Cpp.Direct(&s); + // CHECK:STDERR: ^~~~~~~~~~~~~~ + // CHECK:STDERR: fail_import_deduced_pointer_param_as_pointer.carbon:[[@LINE+4]]:3: note: in call to Cpp function here [InCallToCppFunction] + // CHECK:STDERR: Cpp.Direct(&s); + // CHECK:STDERR: ^~~~~~~~~~~~~~ + // CHECK:STDERR: + Cpp.Direct(&s); + + // CHECK:STDERR: fail_import_deduced_pointer_param_as_pointer.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: return type: AddPointer` [SemanticsTodo] + // CHECK:STDERR: Cpp.Indirect({} as Cpp.S); + // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~ + // CHECK:STDERR: fail_import_deduced_pointer_param_as_pointer.carbon:[[@LINE+4]]:3: note: in call to Cpp function here [InCallToCppFunction] + // CHECK:STDERR: Cpp.Indirect({} as Cpp.S); + // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~ + // CHECK:STDERR: + Cpp.Indirect({} as Cpp.S); + //@dump-sem-ir-end +} + // CHECK:STDOUT: --- import_pointer_param.carbon // CHECK:STDOUT: // CHECK:STDOUT: constants { @@ -600,3 +669,156 @@ fn F() { // CHECK:STDOUT: // CHECK:STDOUT: } // CHECK:STDOUT: +// CHECK:STDOUT: --- import_deduced_any_param_as_pointer.carbon +// CHECK:STDOUT: +// CHECK:STDOUT: constants { +// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete] +// CHECK:STDOUT: %S: type = class_type @S [concrete] +// CHECK:STDOUT: %empty_struct_type: type = struct_type {} [concrete] +// CHECK:STDOUT: %pattern_type.7da: type = pattern_type %S [concrete] +// CHECK:STDOUT: %S.val: %S = struct_value () [concrete] +// CHECK:STDOUT: %ptr.5c7: type = ptr_type %S [concrete] +// CHECK:STDOUT: %pattern_type.259: type = pattern_type %ptr.5c7 [concrete] +// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @foo [concrete] +// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete] +// CHECK:STDOUT: %foo.type: type = fn_type @foo [concrete] +// CHECK:STDOUT: %foo: %foo.type = struct_value () [concrete] +// CHECK:STDOUT: %T.as.Destroy.impl.Op.type.d46: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%S) [concrete] +// CHECK:STDOUT: %T.as.Destroy.impl.Op.062: %T.as.Destroy.impl.Op.type.d46 = struct_value () [concrete] +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: imports { +// CHECK:STDOUT: %Cpp: = namespace file.%Cpp.import_cpp, [concrete] { +// CHECK:STDOUT: .S = %S.decl +// CHECK:STDOUT: .foo = %.a21 +// CHECK:STDOUT: import Cpp//... +// CHECK:STDOUT: } +// CHECK:STDOUT: %S.decl: type = class_decl @S [concrete = constants.%S] {} {} +// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @foo [concrete = constants.%empty_struct] +// CHECK:STDOUT: %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] { +// CHECK:STDOUT: +// CHECK:STDOUT: } { +// CHECK:STDOUT: +// CHECK:STDOUT: } +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: fn @F() { +// CHECK:STDOUT: !entry: +// CHECK:STDOUT: name_binding_decl { +// CHECK:STDOUT: %s.patt: %pattern_type.7da = binding_pattern s [concrete] +// CHECK:STDOUT: %s.var_patt: %pattern_type.7da = var_pattern %s.patt [concrete] +// CHECK:STDOUT: } +// CHECK:STDOUT: %s.var: ref %S = var %s.var_patt +// CHECK:STDOUT: %.loc8_19.1: %empty_struct_type = struct_literal () +// CHECK:STDOUT: %.loc8_19.2: init %S = class_init (), %s.var [concrete = constants.%S.val] +// CHECK:STDOUT: %.loc8_3: init %S = converted %.loc8_19.1, %.loc8_19.2 [concrete = constants.%S.val] +// CHECK:STDOUT: assign %s.var, %.loc8_3 +// CHECK:STDOUT: %.loc8_13: type = splice_block %S.ref.loc8 [concrete = constants.%S] { +// CHECK:STDOUT: %Cpp.ref.loc8: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %S.ref.loc8: type = name_ref S, imports.%S.decl [concrete = constants.%S] +// CHECK:STDOUT: } +// CHECK:STDOUT: %s: ref %S = bind_name s, %s.var +// CHECK:STDOUT: name_binding_decl { +// CHECK:STDOUT: %p.patt: %pattern_type.259 = binding_pattern p [concrete] +// CHECK:STDOUT: } +// CHECK:STDOUT: %Cpp.ref.loc9_19: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct] +// CHECK:STDOUT: %s.ref: ref %S = name_ref s, %s +// CHECK:STDOUT: %addr.loc9: %ptr.5c7 = addr_of %s.ref +// CHECK:STDOUT: %foo.call: init %ptr.5c7 = call imports.%foo.decl(%addr.loc9) +// CHECK:STDOUT: %.loc9_15: type = splice_block %ptr [concrete = constants.%ptr.5c7] { +// CHECK:STDOUT: %Cpp.ref.loc9_10: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %S.ref.loc9: type = name_ref S, imports.%S.decl [concrete = constants.%S] +// CHECK:STDOUT: %ptr: type = ptr_type %S.ref.loc9 [concrete = constants.%ptr.5c7] +// CHECK:STDOUT: } +// CHECK:STDOUT: %.loc9_29.1: %ptr.5c7 = value_of_initializer %foo.call +// CHECK:STDOUT: %.loc9_29.2: %ptr.5c7 = converted %foo.call, %.loc9_29.1 +// CHECK:STDOUT: %p: %ptr.5c7 = bind_name p, %.loc9_29.2 +// CHECK:STDOUT: %T.as.Destroy.impl.Op.bound: = bound_method %s.var, constants.%T.as.Destroy.impl.Op.062 +// CHECK:STDOUT: +// CHECK:STDOUT: %bound_method: = bound_method %s.var, %T.as.Destroy.impl.Op.specific_fn +// CHECK:STDOUT: %addr.loc8: %ptr.5c7 = addr_of %s.var +// CHECK:STDOUT: %T.as.Destroy.impl.Op.call: init %empty_tuple.type = call %bound_method(%addr.loc8) +// CHECK:STDOUT: +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: --- fail_import_deduced_pointer_param_as_pointer.carbon +// CHECK:STDOUT: +// CHECK:STDOUT: constants { +// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete] +// CHECK:STDOUT: %S: type = class_type @S [concrete] +// CHECK:STDOUT: %empty_struct_type: type = struct_type {} [concrete] +// CHECK:STDOUT: %pattern_type.7da: type = pattern_type %S [concrete] +// CHECK:STDOUT: %S.val: %S = struct_value () [concrete] +// CHECK:STDOUT: %.97c: type = cpp_overload_set_type @Destroy.Op [concrete] +// CHECK:STDOUT: %empty_struct.504: %.97c = struct_value () [concrete] +// CHECK:STDOUT: %ptr.5c7: type = ptr_type %S [concrete] +// CHECK:STDOUT: %.fed: type = cpp_overload_set_type @T.as.Destroy.impl.Op [concrete] +// CHECK:STDOUT: %empty_struct.6e8: %.fed = struct_value () [concrete] +// CHECK:STDOUT: %Indirect.type: type = fn_type @Indirect [concrete] +// CHECK:STDOUT: %Indirect: %Indirect.type = struct_value () [concrete] +// CHECK:STDOUT: %T.as.Destroy.impl.Op.type.d46: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%S) [concrete] +// CHECK:STDOUT: %T.as.Destroy.impl.Op.062: %T.as.Destroy.impl.Op.type.d46 = struct_value () [concrete] +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: imports { +// CHECK:STDOUT: %Cpp: = namespace file.%Cpp.import_cpp, [concrete] { +// CHECK:STDOUT: .S = %S.decl +// CHECK:STDOUT: .Direct = %.e4a +// CHECK:STDOUT: .Indirect = %.9c4 +// CHECK:STDOUT: import Cpp//... +// CHECK:STDOUT: } +// CHECK:STDOUT: %S.decl: type = class_decl @S [concrete = constants.%S] {} {} +// CHECK:STDOUT: %.e4a: %.97c = cpp_overload_set_value @Destroy.Op [concrete = constants.%empty_struct.504] +// CHECK:STDOUT: %.9c4: %.fed = cpp_overload_set_value @T.as.Destroy.impl.Op [concrete = constants.%empty_struct.6e8] +// CHECK:STDOUT: %Indirect.decl: %Indirect.type = fn_decl @Indirect [concrete = constants.%Indirect] { +// CHECK:STDOUT: +// CHECK:STDOUT: } { +// CHECK:STDOUT: +// CHECK:STDOUT: } +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: fn @F() { +// CHECK:STDOUT: !entry: +// CHECK:STDOUT: name_binding_decl { +// CHECK:STDOUT: %s.patt: %pattern_type.7da = binding_pattern s [concrete] +// CHECK:STDOUT: %s.var_patt: %pattern_type.7da = var_pattern %s.patt [concrete] +// CHECK:STDOUT: } +// CHECK:STDOUT: %s.var: ref %S = var %s.var_patt +// CHECK:STDOUT: %.loc8_19.1: %empty_struct_type = struct_literal () +// CHECK:STDOUT: %.loc8_19.2: init %S = class_init (), %s.var [concrete = constants.%S.val] +// CHECK:STDOUT: %.loc8_3: init %S = converted %.loc8_19.1, %.loc8_19.2 [concrete = constants.%S.val] +// CHECK:STDOUT: assign %s.var, %.loc8_3 +// CHECK:STDOUT: %.loc8_13: type = splice_block %S.ref.loc8 [concrete = constants.%S] { +// CHECK:STDOUT: %Cpp.ref.loc8: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %S.ref.loc8: type = name_ref S, imports.%S.decl [concrete = constants.%S] +// CHECK:STDOUT: } +// CHECK:STDOUT: %s: ref %S = bind_name s, %s.var +// CHECK:STDOUT: %Cpp.ref.loc16: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %Direct.ref: %.97c = name_ref Direct, imports.%.e4a [concrete = constants.%empty_struct.504] +// CHECK:STDOUT: %s.ref: ref %S = name_ref s, %s +// CHECK:STDOUT: %addr.loc16: %ptr.5c7 = addr_of %s.ref +// CHECK:STDOUT: %Cpp.ref.loc25_3: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %Indirect.ref: %.fed = name_ref Indirect, imports.%.9c4 [concrete = constants.%empty_struct.6e8] +// CHECK:STDOUT: %.loc25_17.1: %empty_struct_type = struct_literal () +// CHECK:STDOUT: %Cpp.ref.loc25_22: = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp] +// CHECK:STDOUT: %S.ref.loc25: type = name_ref S, imports.%S.decl [concrete = constants.%S] +// CHECK:STDOUT: %.loc25_17.2: ref %S = temporary_storage +// CHECK:STDOUT: %.loc25_17.3: init %S = class_init (), %.loc25_17.2 [concrete = constants.%S.val] +// CHECK:STDOUT: %.loc25_17.4: ref %S = temporary %.loc25_17.2, %.loc25_17.3 +// CHECK:STDOUT: %.loc25_19.1: ref %S = converted %.loc25_17.1, %.loc25_17.4 +// CHECK:STDOUT: %.loc25_19.2: %S = bind_value %.loc25_19.1 +// CHECK:STDOUT: %Indirect.call: init = call imports.%Indirect.decl(%.loc25_19.2) +// CHECK:STDOUT: %T.as.Destroy.impl.Op.bound.loc25: = bound_method %.loc25_17.4, constants.%T.as.Destroy.impl.Op.062 +// CHECK:STDOUT: +// CHECK:STDOUT: %bound_method.loc25: = bound_method %.loc25_17.4, %T.as.Destroy.impl.Op.specific_fn.1 +// CHECK:STDOUT: %addr.loc25: %ptr.5c7 = addr_of %.loc25_17.4 +// CHECK:STDOUT: %T.as.Destroy.impl.Op.call.loc25: init %empty_tuple.type = call %bound_method.loc25(%addr.loc25) +// CHECK:STDOUT: %T.as.Destroy.impl.Op.bound.loc8: = bound_method %s.var, constants.%T.as.Destroy.impl.Op.062 +// CHECK:STDOUT: +// CHECK:STDOUT: %bound_method.loc8: = bound_method %s.var, %T.as.Destroy.impl.Op.specific_fn.2 +// CHECK:STDOUT: %addr.loc8: %ptr.5c7 = addr_of %s.var +// CHECK:STDOUT: %T.as.Destroy.impl.Op.call.loc8: init %empty_tuple.type = call %bound_method.loc8(%addr.loc8) +// CHECK:STDOUT: +// CHECK:STDOUT: } +// CHECK:STDOUT: