Move google-explicit-constructor check to a separate source file.

Summary: No functional changes.

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D4188

llvm-svn: 211154

1 files changed, 85 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/google/ExplicitConstructorCheck.cpp b/clang-tools-extra/clang-tidy/google/ExplicitConstructorCheck.cpp
new file mode 100644
index 00000000000..764f18031c8
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/google/ExplicitConstructorCheck.cpp
@@ -0,0 +1,85 @@
+//===--- ExplicitConstructorCheck.cpp - clang-tidy ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ExplicitConstructorCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+
+void ExplicitConstructorCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(constructorDecl().bind("ctor"), this);
+}
+
+// Looks for the token matching the predicate and returns the range of the found
+// token including trailing whitespace.
+SourceRange FindToken(const SourceManager &Sources, LangOptions LangOpts,
+                      SourceLocation StartLoc, SourceLocation EndLoc,
+                      bool (*Pred)(const Token &)) {
+  if (StartLoc.isMacroID() || EndLoc.isMacroID())
+    return SourceRange();
+  FileID File = Sources.getFileID(Sources.getSpellingLoc(StartLoc));
+  StringRef Buf = Sources.getBufferData(File);
+  const char *StartChar = Sources.getCharacterData(StartLoc);
+  Lexer Lex(StartLoc, LangOpts, StartChar, StartChar, Buf.end());
+  Lex.SetCommentRetentionState(true);
+  Token Tok;
+  do {
+    Lex.LexFromRawLexer(Tok);
+    if (Pred(Tok)) {
+      Token NextTok;
+      Lex.LexFromRawLexer(NextTok);
+      return SourceRange(Tok.getLocation(), NextTok.getLocation());
+    }
+  } while (Tok.isNot(tok::eof) && Tok.getLocation() < EndLoc);
+
+  return SourceRange();
+}
+
+void ExplicitConstructorCheck::check(const MatchFinder::MatchResult &Result) {
+  const CXXConstructorDecl *Ctor =
+      Result.Nodes.getNodeAs<CXXConstructorDecl>("ctor");
+  // Do not be confused: isExplicit means 'explicit' keyword is present,
+  // isImplicit means that it's a compiler-generated constructor.
+  if (Ctor->isOutOfLine() || Ctor->isImplicit() || Ctor->isDeleted())
+    return;
+
+  if (Ctor->isExplicit() && Ctor->isCopyOrMoveConstructor()) {
+    auto isKWExplicit = [](const Token &Tok) {
+      return Tok.is(tok::raw_identifier) &&
+             Tok.getRawIdentifier() == "explicit";
+    };
+    SourceRange ExplicitTokenRange =
+        FindToken(*Result.SourceManager, Result.Context->getLangOpts(),
+                  Ctor->getOuterLocStart(), Ctor->getLocEnd(), isKWExplicit);
+    DiagnosticBuilder Diag =
+        diag(Ctor->getLocation(), "%0 constructor declared explicit.")
+        << (Ctor->isMoveConstructor() ? "Move" : "Copy");
+    if (ExplicitTokenRange.isValid()) {
+      Diag << FixItHint::CreateRemoval(
+          CharSourceRange::getCharRange(ExplicitTokenRange));
+    }
+  }
+
+  if (Ctor->isExplicit() || Ctor->isCopyOrMoveConstructor() ||
+      Ctor->getNumParams() == 0 || Ctor->getMinRequiredArguments() > 1)
+    return;
+
+  SourceLocation Loc = Ctor->getLocation();
+  diag(Loc, "Single-argument constructors must be explicit")
+      << FixItHint::CreateInsertion(Loc, "explicit ");
+}
+
+} // namespace tidy
+} // namespace clang