94 lines · cpp
1//===--- ExpectedTypes.cpp ---------------------------------------*- C++-*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "ExpectedTypes.h"10#include "clang/AST/ASTContext.h"11#include "clang/AST/DeclTemplate.h"12#include "clang/AST/Type.h"13#include "clang/Index/USRGeneration.h"14#include "clang/Sema/CodeCompleteConsumer.h"15#include <optional>16 17namespace clang {18namespace clangd {19namespace {20 21static const Type *toEquivClass(ASTContext &Ctx, QualType T) {22 if (T.isNull() || T->isDependentType())23 return nullptr;24 // Drop references, we do not handle reference inits properly anyway.25 T = T.getCanonicalType().getNonReferenceType();26 // Numeric types are the simplest case.27 if (T->isBooleanType())28 return Ctx.BoolTy.getTypePtr();29 if (T->isIntegerType() && !T->isEnumeralType())30 return Ctx.IntTy.getTypePtr(); // All integers are equivalent.31 if (T->isFloatingType() && !T->isComplexType())32 return Ctx.FloatTy.getTypePtr(); // All floats are equivalent.33 34 // Do some simple transformations.35 if (T->isArrayType()) // Decay arrays to pointers.36 return Ctx.getPointerType(QualType(T->getArrayElementTypeNoTypeQual(), 0))37 .getTypePtr();38 // Drop the qualifiers and return the resulting type.39 // FIXME: also drop qualifiers from pointer types, e.g. 'const T* => T*'40 return T.getTypePtr();41}42 43static std::optional<QualType> typeOfCompletion(const CodeCompletionResult &R) {44 const NamedDecl *D = R.Declaration;45 // Templates do not have a type on their own, look at the templated decl.46 if (auto *Template = dyn_cast_or_null<TemplateDecl>(D))47 D = Template->getTemplatedDecl();48 auto *VD = dyn_cast_or_null<ValueDecl>(D);49 if (!VD)50 return std::nullopt; // We handle only variables and functions below.51 auto T = VD->getType();52 if (T.isNull())53 return std::nullopt;54 if (auto *FuncT = T->getAs<FunctionType>()) {55 // Functions are a special case. They are completed as 'foo()' and we want56 // to match their return type rather than the function type itself.57 // FIXME(ibiryukov): in some cases, we might want to avoid completing `()`58 // after the function name, e.g. `std::cout << std::endl`.59 return FuncT->getReturnType();60 }61 return T;62}63} // namespace64 65std::optional<OpaqueType> OpaqueType::encode(ASTContext &Ctx, QualType T) {66 if (T.isNull())67 return std::nullopt;68 const Type *C = toEquivClass(Ctx, T);69 if (!C)70 return std::nullopt;71 llvm::SmallString<128> Encoded;72 if (index::generateUSRForType(QualType(C, 0), Ctx, Encoded))73 return std::nullopt;74 return OpaqueType(std::string(Encoded));75}76 77OpaqueType::OpaqueType(std::string Data) : Data(std::move(Data)) {}78 79std::optional<OpaqueType> OpaqueType::fromType(ASTContext &Ctx, QualType Type) {80 return encode(Ctx, Type);81}82 83std::optional<OpaqueType>84OpaqueType::fromCompletionResult(ASTContext &Ctx,85 const CodeCompletionResult &R) {86 auto T = typeOfCompletion(R);87 if (!T)88 return std::nullopt;89 return encode(Ctx, *T);90}91 92} // namespace clangd93} // namespace clang94