1 files changed, 63 insertions, 0 deletions
diff --git a/clang-tools-extra/cpp11-migrate/UseAuto/UseAutoActions.cpp b/clang-tools-extra/cpp11-migrate/UseAuto/UseAutoActions.cpp
new file mode 100644
index 00000000000..ceb22390a1f
--- /dev/null
+++ b/clang-tools-extra/cpp11-migrate/UseAuto/UseAutoActions.cpp
@@ -0,0 +1,63 @@
+//===-- UseAuto/UseAutoActions.cpp - Matcher callback impl ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+///  \file
+///  \brief This file contains the implementation of the UseAutoFixer class.
+///
+//===----------------------------------------------------------------------===//
+#include "UseAutoActions.h"
+#include "UseAutoMatchers.h"
+#include "clang/AST/ASTContext.h"
+
+using namespace clang::ast_matchers;
+using namespace clang::tooling;
+using namespace clang;
+
+void UseAutoFixer::run(const MatchFinder::MatchResult &Result) {
+  const VarDecl *D = Result.Nodes.getNodeAs<VarDecl>(DeclNodeId);
+
+  assert(D && "Bad Callback. No node provided");
+
+  SourceManager &SM = *Result.SourceManager;
+  if (!SM.isFromMainFile(D->getLocStart()))
+    return;
+
+  const CXXConstructExpr *Construct = cast<CXXConstructExpr>(D->getInit());
+  assert(Construct->getNumArgs() == 1u &&
+         "Expected constructor with single argument");
+
+  // Drill down to the as-written initializer.
+  const Expr *E = Construct->arg_begin()->IgnoreParenImpCasts();
+  if (E != E->IgnoreConversionOperator())
+    // We hit a conversion operator. Early-out now as they imply an implicit
+    // conversion from a different type. Could also mean an explicit conversion
+    // from the same type but that's pretty rare.
+    return;
+
+  if (const CXXConstructExpr *NestedConstruct = dyn_cast<CXXConstructExpr>(E))
+    // If we ran into an implicit conversion constructor, can't convert.
+    //
+    // FIXME: The following only checks if the constructor can be used
+    // implicitly, not if it actually was. Cases where the converting constructor
+    // was used explicitly won't get converted.
+    if (NestedConstruct->getConstructor()->isConvertingConstructor(false))
+      return;
+
+  if (Result.Context->hasSameType(D->getType(), E->getType())) {
+    TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
+
+    // WARNING: TypeLoc::getSourceRange() will include the identifier for things
+    // like function pointers. Not a concern since this action only works with
+    // iterators but something to keep in mind in the future.
+
+    CharSourceRange Range(TL.getSourceRange(), true);
+    Replace.insert(tooling::Replacement(SM, Range, "auto"));
+    ++AcceptedChanges;
+  }
+}