clang-tools  16.0.0git
ExpectedTypes.cpp
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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-exception
6 //
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 "llvm/ADT/None.h"
16 
17 namespace clang {
18 namespace clangd {
19 namespace {
20 
21 static 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 
43 static llvm::Optional<QualType>
44 typeOfCompletion(const CodeCompletionResult &R) {
45  const NamedDecl *D = R.Declaration;
46  // Templates do not have a type on their own, look at the templated decl.
47  if (auto *Template = dyn_cast_or_null<TemplateDecl>(D))
48  D = Template->getTemplatedDecl();
49  auto *VD = dyn_cast_or_null<ValueDecl>(D);
50  if (!VD)
51  return llvm::None; // We handle only variables and functions below.
52  auto T = VD->getType();
53  if (T.isNull())
54  return llvm::None;
55  if (auto *FuncT = T->getAs<FunctionType>()) {
56  // Functions are a special case. They are completed as 'foo()' and we want
57  // to match their return type rather than the function type itself.
58  // FIXME(ibiryukov): in some cases, we might want to avoid completing `()`
59  // after the function name, e.g. `std::cout << std::endl`.
60  return FuncT->getReturnType();
61  }
62  return T;
63 }
64 } // namespace
65 
66 llvm::Optional<OpaqueType> OpaqueType::encode(ASTContext &Ctx, QualType T) {
67  if (T.isNull())
68  return None;
69  const Type *C = toEquivClass(Ctx, T);
70  if (!C)
71  return None;
72  llvm::SmallString<128> Encoded;
73  if (index::generateUSRForType(QualType(C, 0), Ctx, Encoded))
74  return None;
75  return OpaqueType(std::string(Encoded.str()));
76 }
77 
78 OpaqueType::OpaqueType(std::string Data) : Data(std::move(Data)) {}
79 
80 llvm::Optional<OpaqueType> OpaqueType::fromType(ASTContext &Ctx,
81  QualType Type) {
82  return encode(Ctx, Type);
83 }
84 
85 llvm::Optional<OpaqueType>
86 OpaqueType::fromCompletionResult(ASTContext &Ctx,
87  const CodeCompletionResult &R) {
88  auto T = typeOfCompletion(R);
89  if (!T)
90  return None;
91  return encode(Ctx, *T);
92 }
93 
94 } // namespace clangd
95 } // namespace clang
Type
NodeType Type
Definition: HTMLGenerator.cpp:73
Ctx
Context Ctx
Definition: TUScheduler.cpp:553
ns1::ns2::D
@ D
Definition: CategoricalFeature.h:3
ExpectedTypes.h
clang::tidy::bugprone::model::MixFlags::None
@ None
Mix between the two parameters is not possible.
C
const Criteria C
Definition: FunctionCognitiveComplexityCheck.cpp:93
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27