Use 'auto const&' for iterators whose deref operator return a const var

This patch fixes PR15601.
- Added check for whether the loop variable and the initializer have the same
type.
- Added tests.

llvm-svn: 181528

1 files changed, 9 insertions, 1 deletions

diff --git a/clang-tools-extra/test/cpp11-migrate/LoopConvert/naming-conflict.cpp b/clang-tools-extra/test/cpp11-migrate/LoopConvert/naming-conflict.cpp
index 050f44ef900..9597c63a6f2 100644
--- a/clang-tools-extra/test/cpp11-migrate/LoopConvert/naming-conflict.cpp
+++ b/clang-tools-extra/test/cpp11-migrate/LoopConvert/naming-conflict.cpp
@@ -32,7 +32,7 @@ void sameNames() {
 
 void macroConflict() {
   S MAXs;
-  for (S::const_iterator it = MAXs.begin(), e = MAXs.end(); it != e; ++it) {
+  for (S::iterator it = MAXs.begin(), e = MAXs.end(); it != e; ++it) {
     printf("s has value %d\n", (*it).x);
     printf("Max of 3 and 5: %d\n", MAX(3,5));
   }
@@ -40,6 +40,14 @@ void macroConflict() {
   // CHECK-NEXT: printf("s has value %d\n", (MAXs_it).x);
   // CHECK-NEXT: printf("Max of 3 and 5: %d\n", MAX(3,5));
 
+  for (S::const_iterator it = MAXs.begin(), e = MAXs.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+    printf("Max of 3 and 5: %d\n", MAX(3,5));
+  }
+  // CHECK: for (auto const & MAXs_it : MAXs)
+  // CHECK-NEXT: printf("s has value %d\n", (MAXs_it).x);
+  // CHECK-NEXT: printf("Max of 3 and 5: %d\n", MAX(3,5));
+
   T DEFs;
   for (T::iterator it = DEFs.begin(), e = DEFs.end(); it != e; ++it) {
     if (*it == DEF) {