clang-tools  3.9.0
ExplicitMakePairCheck.cpp
Go to the documentation of this file.
1 //===--- ExplicitMakePairCheck.cpp - clang-tidy -----------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "ExplicitMakePairCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/ASTMatchers/ASTMatchers.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace {
19 AST_MATCHER(DeclRefExpr, hasExplicitTemplateArgs) {
20  return Node.hasExplicitTemplateArgs();
21 }
22 } // namespace
23 
24 namespace tidy {
25 namespace google {
26 namespace build {
27 
28 void
29 ExplicitMakePairCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
30  // Only register the matchers for C++; the functionality currently does not
31  // provide any benefit to other languages, despite being benign.
32  if (!getLangOpts().CPlusPlus)
33  return;
34 
35  // Look for std::make_pair with explicit template args. Ignore calls in
36  // templates.
37  Finder->addMatcher(
38  callExpr(unless(isInTemplateInstantiation()),
39  callee(expr(ignoringParenImpCasts(
40  declRefExpr(hasExplicitTemplateArgs(),
41  to(functionDecl(hasName("::std::make_pair"))))
42  .bind("declref"))))).bind("call"),
43  this);
44 }
45 
46 void ExplicitMakePairCheck::check(const MatchFinder::MatchResult &Result) {
47  const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call");
48  const auto *DeclRef = Result.Nodes.getNodeAs<DeclRefExpr>("declref");
49 
50  // Sanity check: The use might have overriden ::std::make_pair.
51  if (Call->getNumArgs() != 2)
52  return;
53 
54  const Expr *Arg0 = Call->getArg(0)->IgnoreParenImpCasts();
55  const Expr *Arg1 = Call->getArg(1)->IgnoreParenImpCasts();
56 
57  // If types don't match, we suggest replacing with std::pair and explicit
58  // template arguments. Otherwise just remove the template arguments from
59  // make_pair.
60  if (Arg0->getType() != Call->getArg(0)->getType() ||
61  Arg1->getType() != Call->getArg(1)->getType()) {
62  diag(Call->getLocStart(), "for C++11-compatibility, use pair directly")
63  << FixItHint::CreateReplacement(
64  SourceRange(DeclRef->getLocStart(), DeclRef->getLAngleLoc()),
65  "std::pair<");
66  } else {
67  diag(Call->getLocStart(),
68  "for C++11-compatibility, omit template arguments from make_pair")
69  << FixItHint::CreateRemoval(
70  SourceRange(DeclRef->getLAngleLoc(), DeclRef->getRAngleLoc()));
71  }
72 }
73 
74 } // namespace build
75 } // namespace google
76 } // namespace tidy
77 } // namespace clang
AST_MATCHER(Type, isStrictlyInteger)
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:210
const NamedDecl * Result
Definition: USRFinder.cpp:137