xref: /llvm-project/clang/lib/AST/Availability.cpp (revision 026d963cb004689477d2b5798cbba5ad41c25a70)
1 //===- Availability.cpp --------------------------------------------------===//
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 // This file implements the Availability information for Decls.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/Availability.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/Attr.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/Basic/TargetInfo.h"
18 
19 namespace {
20 
21 /// Represents the availability of a symbol across platforms.
22 struct AvailabilitySet {
23   bool UnconditionallyDeprecated = false;
24   bool UnconditionallyUnavailable = false;
25 
26   void insert(clang::AvailabilityInfo &&Availability) {
27     auto *Found = getForPlatform(Availability.Domain);
28     if (Found)
29       Found->mergeWith(std::move(Availability));
30     else
31       Availabilities.emplace_back(std::move(Availability));
32   }
33 
34   clang::AvailabilityInfo *getForPlatform(llvm::StringRef Domain) {
35     auto *It = llvm::find_if(Availabilities,
36                              [Domain](const clang::AvailabilityInfo &Info) {
37                                return Domain.compare(Info.Domain) == 0;
38                              });
39     return It == Availabilities.end() ? nullptr : It;
40   }
41 
42 private:
43   llvm::SmallVector<clang::AvailabilityInfo> Availabilities;
44 };
45 
46 static void createInfoForDecl(const clang::Decl *Decl,
47                               AvailabilitySet &Availabilities) {
48   // Collect availability attributes from all redeclarations.
49   for (const auto *RD : Decl->redecls()) {
50     for (const auto *A : RD->specific_attrs<clang::AvailabilityAttr>()) {
51       Availabilities.insert(clang::AvailabilityInfo(
52           A->getPlatform()->getName(), A->getIntroduced(), A->getDeprecated(),
53           A->getObsoleted(), A->getUnavailable(), false, false));
54     }
55 
56     if (const auto *A = RD->getAttr<clang::UnavailableAttr>())
57       if (!A->isImplicit())
58         Availabilities.UnconditionallyUnavailable = true;
59 
60     if (const auto *A = RD->getAttr<clang::DeprecatedAttr>())
61       if (!A->isImplicit())
62         Availabilities.UnconditionallyDeprecated = true;
63   }
64 }
65 
66 } // namespace
67 
68 namespace clang {
69 
70 void AvailabilityInfo::mergeWith(AvailabilityInfo Other) {
71   if (isDefault() && Other.isDefault())
72     return;
73 
74   if (Domain.empty())
75     Domain = Other.Domain;
76 
77   UnconditionallyUnavailable |= Other.UnconditionallyUnavailable;
78   UnconditionallyDeprecated |= Other.UnconditionallyDeprecated;
79   Unavailable |= Other.Unavailable;
80 
81   Introduced = std::max(Introduced, Other.Introduced);
82 
83   // Default VersionTuple is 0.0.0 so if both are non default let's pick the
84   // smallest version number, otherwise select the one that is non-zero if there
85   // is one.
86   if (!Deprecated.empty() && !Other.Deprecated.empty())
87     Deprecated = std::min(Deprecated, Other.Deprecated);
88   else
89     Deprecated = std::max(Deprecated, Other.Deprecated);
90 
91   if (!Obsoleted.empty() && !Other.Obsoleted.empty())
92     Obsoleted = std::min(Obsoleted, Other.Obsoleted);
93   else
94     Obsoleted = std::max(Obsoleted, Other.Obsoleted);
95 }
96 
97 AvailabilityInfo AvailabilityInfo::createFromDecl(const Decl *D) {
98   AvailabilitySet Availabilities;
99   // Walk DeclContexts upwards starting from D to find the combined availability
100   // of the symbol.
101   for (const auto *Ctx = D; Ctx;
102        Ctx = llvm::cast_or_null<Decl>(Ctx->getDeclContext()))
103     createInfoForDecl(Ctx, Availabilities);
104 
105   if (auto *Avail = Availabilities.getForPlatform(
106           D->getASTContext().getTargetInfo().getPlatformName())) {
107     Avail->UnconditionallyDeprecated = Availabilities.UnconditionallyDeprecated;
108     Avail->UnconditionallyUnavailable =
109         Availabilities.UnconditionallyUnavailable;
110     return std::move(*Avail);
111   }
112 
113   AvailabilityInfo Avail;
114   Avail.UnconditionallyDeprecated = Availabilities.UnconditionallyDeprecated;
115   Avail.UnconditionallyUnavailable = Availabilities.UnconditionallyUnavailable;
116   return Avail;
117 }
118 
119 } // namespace clang
120