summaryrefslogtreecommitdiffstats
path: root/clangd/AST.cpp
blob: 113069a09eb0e96a1e8096a63938d77c99437678 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
//===--- AST.cpp - Utility AST functions  -----------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "AST.h"

#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/TemplateBase.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Index/USRGeneration.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"

namespace clang {
namespace clangd {

namespace {
llvm::Optional<llvm::ArrayRef<TemplateArgumentLoc>>
getTemplateSpecializationArgLocs(const NamedDecl &ND) {
  if (auto *Func = llvm::dyn_cast<FunctionDecl>(&ND)) {
    if (const ASTTemplateArgumentListInfo *Args =
            Func->getTemplateSpecializationArgsAsWritten())
      return Args->arguments();
  } else if (auto *Cls =
                 llvm::dyn_cast<ClassTemplatePartialSpecializationDecl>(&ND)) {
    if (auto *Args = Cls->getTemplateArgsAsWritten())
      return Args->arguments();
  } else if (auto *Var = llvm::dyn_cast<VarTemplateSpecializationDecl>(&ND))
    return Var->getTemplateArgsInfo().arguments();
  // We return None for ClassTemplateSpecializationDecls because it does not
  // contain TemplateArgumentLoc information.
  return llvm::None;
}
} // namespace

// Returns true if the complete name of decl \p D is spelled in the source code.
// This is not the case for:
//   * symbols formed via macro concatenation, the spelling location will
//     be "<scratch space>"
//   * symbols controlled and defined by a compile command-line option
//     `-DName=foo`, the spelling location will be "<command line>".
bool isSpelledInSourceCode(const Decl *D) {
  const auto &SM = D->getASTContext().getSourceManager();
  auto Loc = D->getLocation();
  // FIXME: Revisit the strategy, the heuristic is limitted when handling
  // macros, we should use the location where the whole definition occurs.
  if (Loc.isMacroID()) {
    std::string PrintLoc = SM.getSpellingLoc(Loc).printToString(SM);
    if (llvm::StringRef(PrintLoc).startswith("<scratch") ||
        llvm::StringRef(PrintLoc).startswith("<command line>"))
      return false;
  }
  return true;
}

bool isImplementationDetail(const Decl *D) { return !isSpelledInSourceCode(D); }

SourceLocation findNameLoc(const clang::Decl *D) {
  const auto &SM = D->getASTContext().getSourceManager();
  if (!isSpelledInSourceCode(D))
    // Use the expansion location as spelling location is not interesting.
    return SM.getExpansionRange(D->getLocation()).getBegin();
  return SM.getSpellingLoc(D->getLocation());
}

std::string printQualifiedName(const NamedDecl &ND) {
  std::string QName;
  llvm::raw_string_ostream OS(QName);
  PrintingPolicy Policy(ND.getASTContext().getLangOpts());
  // Note that inline namespaces are treated as transparent scopes. This
  // reflects the way they're most commonly used for lookup. Ideally we'd
  // include them, but at query time it's hard to find all the inline
  // namespaces to query: the preamble doesn't have a dedicated list.
  Policy.SuppressUnwrittenScope = true;
  ND.printQualifiedName(OS, Policy);
  OS.flush();
  assert(!StringRef(QName).startswith("::"));
  return QName;
}

std::string printName(const ASTContext &Ctx, const NamedDecl &ND) {
  std::string Name;
  llvm::raw_string_ostream Out(Name);
  PrintingPolicy PP(Ctx.getLangOpts());
  // Handle 'using namespace'. They all have the same name - <using-directive>.
  if (auto *UD = llvm::dyn_cast<UsingDirectiveDecl>(&ND)) {
    Out << "using namespace ";
    if (auto *Qual = UD->getQualifier())
      Qual->print(Out, PP);
    UD->getNominatedNamespaceAsWritten()->printName(Out);
    return Out.str();
  }
  ND.getDeclName().print(Out, PP);
  if (!Out.str().empty()) {
    Out << printTemplateSpecializationArgs(ND);
    return Out.str();
  }
  // The name was empty, so present an anonymous entity.
  if (isa<NamespaceDecl>(ND))
    return "(anonymous namespace)";
  if (auto *Cls = llvm::dyn_cast<RecordDecl>(&ND))
    return ("(anonymous " + Cls->getKindName() + ")").str();
  if (isa<EnumDecl>(ND))
    return "(anonymous enum)";
  return "(anonymous)";
}

std::string printTemplateSpecializationArgs(const NamedDecl &ND) {
  std::string TemplateArgs;
  llvm::raw_string_ostream OS(TemplateArgs);
  PrintingPolicy Policy(ND.getASTContext().getLangOpts());
  if (llvm::Optional<llvm::ArrayRef<TemplateArgumentLoc>> Args =
          getTemplateSpecializationArgLocs(ND)) {
    printTemplateArgumentList(OS, *Args, Policy);
  } else if (auto *Cls = llvm::dyn_cast<ClassTemplateSpecializationDecl>(&ND)) {
    if (const TypeSourceInfo *TSI = Cls->getTypeAsWritten()) {
      // ClassTemplateSpecializationDecls do not contain
      // TemplateArgumentTypeLocs, they only have TemplateArgumentTypes. So we
      // create a new argument location list from TypeSourceInfo.
      auto STL = TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>();
      llvm::SmallVector<TemplateArgumentLoc, 8> ArgLocs;
      ArgLocs.reserve(STL.getNumArgs());
      for (unsigned I = 0; I < STL.getNumArgs(); ++I)
        ArgLocs.push_back(STL.getArgLoc(I));
      printTemplateArgumentList(OS, ArgLocs, Policy);
    } else {
      // FIXME: Fix cases when getTypeAsWritten returns null inside clang AST,
      // e.g. friend decls. Currently we fallback to Template Arguments without
      // location information.
      printTemplateArgumentList(OS, Cls->getTemplateArgs().asArray(), Policy);
    }
  }
  OS.flush();
  return TemplateArgs;
}

std::string printNamespaceScope(const DeclContext &DC) {
  for (const auto *Ctx = &DC; Ctx != nullptr; Ctx = Ctx->getParent())
    if (const auto *NS = dyn_cast<NamespaceDecl>(Ctx))
      if (!NS->isAnonymousNamespace() && !NS->isInlineNamespace())
        return printQualifiedName(*NS) + "::";
  return "";
}

llvm::Optional<SymbolID> getSymbolID(const Decl *D) {
  llvm::SmallString<128> USR;
  if (index::generateUSRForDecl(D, USR))
    return None;
  return SymbolID(USR);
}

llvm::Optional<SymbolID> getSymbolID(const IdentifierInfo &II,
                                     const MacroInfo *MI,
                                     const SourceManager &SM) {
  if (MI == nullptr)
    return None;
  llvm::SmallString<128> USR;
  if (index::generateUSRForMacro(II.getName(), MI->getDefinitionLoc(), SM, USR))
    return None;
  return SymbolID(USR);
}

} // namespace clangd
} // namespace clang