Avoid using rvalue references with trivially copyable types.

Summary:
When the dereference operator returns a value that is trivially
copyable (like a pointer), copy it. After this change, modernize-loop-convert
check can be applied to the whole llvm source code without breaking any build
or test.

Reviewers: alexfh, klimek

Subscribers: alexfh, cfe-commits

Differential Revision: http://reviews.llvm.org/D12675

llvm-svn: 246989

1 files changed, 12 insertions, 3 deletions

diff --git a/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp b/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
index 7f31a5f4ca4..1979f1467ad 100644
--- a/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
+++ b/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
@@ -291,7 +291,7 @@ void f() {
          I != E; ++I) {
     }
     // CHECK-MESSAGES: :[[@LINE-4]]:5: warning: use range-based for loop instead
-    // CHECK-FIXES: for (auto && int_ptr : int_ptrs) {
+    // CHECK-FIXES: for (auto int_ptr : int_ptrs) {
   }
 
   // This container uses an iterator where the derefence type is a typedef of
@@ -564,14 +564,23 @@ struct DerefByValue {
   unsigned operator[](int);
 };
 
-void DerefByValueTest() {
+void derefByValueTest() {
   DerefByValue DBV;
   for (unsigned i = 0, e = DBV.size(); i < e; ++i) {
     printf("%d\n", DBV[i]);
   }
   // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
-  // CHECK-FIXES: for (auto && elem : DBV) {
+  // CHECK-FIXES: for (auto elem : DBV) {
+  // CHECK-FIXES-NEXT: printf("%d\n", elem);
 
+  for (unsigned i = 0, e = DBV.size(); i < e; ++i) {
+    auto f = [DBV, i]() {};
+    printf("%d\n", DBV[i]);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto elem : DBV) {
+  // CHECK-FIXES-NEXT: auto f = [DBV, elem]() {};
+  // CHECK-FIXES-NEXT: printf("%d\n", elem);
 }
 
 } // namespace PseudoArray