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https://github.com/carbon-language/carbon-lang.git
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Richard Smith
a9e835f3dc
The caching isn't buying us much, and is adding complexity and divergence between the codepaths for generic and non-generic functions. This means we no longer suppress diagnostics for the second or subsequent time we call a function with an incomplete return type. If we want to add that back, it might be worth considering moving the suppression to `TryToCompleteType` and only diagnosing that a type is incomplete once, regardless of why we're requiring it to be complete.
102 lines
4.0 KiB
C++
102 lines
4.0 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "toolchain/check/function.h"
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#include "toolchain/check/merge.h"
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#include "toolchain/check/subst.h"
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#include "toolchain/sem_ir/ids.h"
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namespace Carbon::Check {
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auto CheckFunctionTypeMatches(Context& context,
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const SemIR::Function& new_function,
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const SemIR::Function& prev_function,
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Substitutions substitutions, bool check_syntax)
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-> bool {
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if (!CheckRedeclParamsMatch(context, DeclParams(new_function),
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DeclParams(prev_function), substitutions,
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check_syntax)) {
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return false;
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}
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// TODO: Pass a specific ID for `prev_function` instead of substitutions and
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// use it here.
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auto new_return_type_id =
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new_function.GetDeclaredReturnType(context.sem_ir());
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auto prev_return_type_id = prev_function.GetDeclaredReturnType(
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context.sem_ir(), SemIR::SpecificId::Invalid);
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if (new_return_type_id == SemIR::TypeId::Error ||
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prev_return_type_id == SemIR::TypeId::Error) {
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return false;
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}
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if (prev_return_type_id.is_valid()) {
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prev_return_type_id =
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SubstType(context, prev_return_type_id, substitutions);
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}
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if (!context.types().AreEqualAcrossDeclarations(new_return_type_id,
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prev_return_type_id)) {
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CARBON_DIAGNOSTIC(
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FunctionRedeclReturnTypeDiffers, Error,
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"Function redeclaration differs because return type is `{0}`.",
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SemIR::TypeId);
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CARBON_DIAGNOSTIC(
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FunctionRedeclReturnTypeDiffersNoReturn, Error,
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"Function redeclaration differs because no return type is provided.");
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auto diag =
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new_return_type_id.is_valid()
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? context.emitter().Build(new_function.decl_id,
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FunctionRedeclReturnTypeDiffers,
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new_return_type_id)
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: context.emitter().Build(new_function.decl_id,
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FunctionRedeclReturnTypeDiffersNoReturn);
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if (prev_return_type_id.is_valid()) {
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CARBON_DIAGNOSTIC(FunctionRedeclReturnTypePrevious, Note,
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"Previously declared with return type `{0}`.",
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SemIR::TypeId);
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diag.Note(prev_function.decl_id, FunctionRedeclReturnTypePrevious,
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prev_return_type_id);
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} else {
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CARBON_DIAGNOSTIC(FunctionRedeclReturnTypePreviousNoReturn, Note,
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"Previously declared with no return type.");
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diag.Note(prev_function.decl_id,
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FunctionRedeclReturnTypePreviousNoReturn);
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}
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diag.Emit();
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return false;
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}
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return true;
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}
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auto CheckFunctionReturnType(Context& context, SemIRLoc loc,
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SemIR::Function& function,
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SemIR::SpecificId specific_id)
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-> SemIR::ReturnInfo {
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auto return_info = function.GetReturnInfo(context.sem_ir(), specific_id);
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// If we couldn't determine the return information due to the return type
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// being incomplete, try to complete it now.
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if (return_info.return_slot == SemIR::ReturnSlot::Incomplete) {
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auto diagnose_incomplete_return_type = [&] {
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CARBON_DIAGNOSTIC(IncompleteTypeInFunctionReturnType, Error,
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"Function returns incomplete type `{0}`.",
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SemIR::TypeId);
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return context.emitter().Build(loc, IncompleteTypeInFunctionReturnType,
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return_info.type_id);
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};
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// TODO: Consider suppressing the diagnostic if we've already diagnosed a
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// definition or call to this function.
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if (context.TryToCompleteType(return_info.type_id,
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diagnose_incomplete_return_type)) {
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return_info = function.GetReturnInfo(context.sem_ir(), specific_id);
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}
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}
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return return_info;
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}
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} // namespace Carbon::Check
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