[clang-tidy] Add a checker that removes deducible arguments from std::make_pair
Those may be incompatible with C++11 and are unnecessary. We suggest
removing the template arguments when they match the types of the make_pair
arguments or replace it with std::pair and explicit template arguments when
not.
Differential Revision: http://reviews.llvm.org/D4497
llvm-svn: 213058
diff --git a/clang-tools-extra/clang-tidy/google/ExplicitMakePairCheck.cpp b/clang-tools-extra/clang-tidy/google/ExplicitMakePairCheck.cpp
new file mode 100644
index 0000000..ae5fbd6
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/google/ExplicitMakePairCheck.cpp
@@ -0,0 +1,71 @@
+//===--- ExplicitMakePairCheck.cpp - clang-tidy -----------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ExplicitMakePairCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/AST/ASTContext.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+
+namespace ast_matchers {
+AST_MATCHER(DeclRefExpr, hasExplicitTemplateArgs) {
+ return Node.hasExplicitTemplateArgs();
+}
+} // namespace ast_matchers
+
+namespace tidy {
+namespace build {
+
+void
+ExplicitMakePairCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
+ // Look for std::make_pair with explicit template args. Ignore calls in
+ // templates.
+ Finder->addMatcher(
+ callExpr(unless(hasAncestor(decl(anyOf(
+ recordDecl(ast_matchers::isTemplateInstantiation()),
+ functionDecl(ast_matchers::isTemplateInstantiation()))))),
+ has(declRefExpr(hasExplicitTemplateArgs()).bind("declref")),
+ callee(functionDecl(hasName("::std::make_pair")))).bind("call"),
+ this);
+}
+
+void ExplicitMakePairCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call");
+ const auto *DeclRef = Result.Nodes.getNodeAs<DeclRefExpr>("declref");
+
+ // Sanity check: The use might have overriden ::std::make_pair.
+ if (Call->getNumArgs() != 2)
+ return;
+
+ const Expr *Arg0 = Call->getArg(0)->IgnoreParenImpCasts();
+ const Expr *Arg1 = Call->getArg(1)->IgnoreParenImpCasts();
+
+ // If types don't match, we suggest replacing with std::pair and explicit
+ // template arguments. Otherwise just remove the template arguments from
+ // make_pair.
+ if (Arg0->getType() != Call->getArg(0)->getType() ||
+ Arg1->getType() != Call->getArg(1)->getType()) {
+ diag(Call->getLocStart(), "for C++11-compatibility, use pair directly")
+ << FixItHint::CreateReplacement(
+ SourceRange(DeclRef->getLocStart(), DeclRef->getLAngleLoc()),
+ "std::pair<");
+ } else {
+ diag(Call->getLocStart(),
+ "for C++11-compatibility, omit template arguments from make_pair")
+ << FixItHint::CreateRemoval(
+ SourceRange(DeclRef->getLAngleLoc(), DeclRef->getRAngleLoc()));
+ }
+}
+
+} // namespace build
+} // namespace tidy
+} // namespace clang