commit 155b8d02c36354c13f2c9a8ec012a95ae0e283b3
author Richard Trieu <rtrieu@google.com> Thu Aug 08 00:12:51 2019 +0000
committer Richard Trieu <rtrieu@google.com> Thu Aug 08 00:12:51 2019 +0000
tree 8576a010dad5b6c43ef790b5f277f7b6e2a00462
parent a87f856f2d9db0c72c3e59e581527f1cb3a9118a

Update fix-it hints for std::move warnings.

Fix -Wpessimizing-move and -Wredundant-move when warning on initializer lists.
The new fix-it hints for removing the std::move call will now also suggest
removing the braces for the initializer list so that the resulting code will
still be compilable.

This fixes PR42832

llvm-svn: 368237

clang/lib/Sema/SemaInit.cpp

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 7fbffd9..693d759 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -7305,27 +7305,34 @@
   if (!DestType->isRecordType())
     return;
 
-  unsigned DiagID = 0;
-  if (IsReturnStmt) {
-    const CXXConstructExpr *CCE =
-        dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
-    if (!CCE || CCE->getNumArgs() != 1)
-      return;
+  const CXXConstructExpr *CCE =
+      dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
+  if (!CCE || CCE->getNumArgs() != 1)
+    return;
 
-    if (!CCE->getConstructor()->isCopyOrMoveConstructor())
-      return;
+  if (!CCE->getConstructor()->isCopyOrMoveConstructor())
+    return;
 
-    InitExpr = CCE->getArg(0)->IgnoreImpCasts();
-  }
+  InitExpr = CCE->getArg(0)->IgnoreImpCasts();
 
   // Find the std::move call and get the argument.
   const CallExpr *CE = dyn_cast<CallExpr>(InitExpr->IgnoreParens());
   if (!CE || !CE->isCallToStdMove())
     return;
 
-  const Expr *Arg = CE->getArg(0)->IgnoreImplicit();
+  const Expr *Arg = CE->getArg(0);
 
-  if (IsReturnStmt) {
+  unsigned DiagID = 0;
+
+  if (!IsReturnStmt && !isa<MaterializeTemporaryExpr>(Arg))
+    return;
+
+  if (isa<MaterializeTemporaryExpr>(Arg)) {
+    DiagID = diag::warn_pessimizing_move_on_initialization;
+    const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
+    if (!ArgStripped->isRValue() || !ArgStripped->getType()->isRecordType())
+      return;
+  } else { // IsReturnStmt
     const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts());
     if (!DRE || DRE->refersToEnclosingVariableOrCapture())
       return;
@@ -7352,24 +7359,18 @@
       DiagID = diag::warn_redundant_move_on_return;
     else
       DiagID = diag::warn_pessimizing_move_on_return;
-  } else {
-    DiagID = diag::warn_pessimizing_move_on_initialization;
-    const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
-    if (!ArgStripped->isRValue() || !ArgStripped->getType()->isRecordType())
-      return;
   }
 
   S.Diag(CE->getBeginLoc(), DiagID);
 
   // Get all the locations for a fix-it.  Don't emit the fix-it if any location
   // is within a macro.
-  SourceLocation CallBegin = CE->getCallee()->getBeginLoc();
-  if (CallBegin.isMacroID())
+  SourceLocation BeginLoc = CCE->getBeginLoc();
+  if (BeginLoc.isMacroID())
     return;
   SourceLocation RParen = CE->getRParenLoc();
   if (RParen.isMacroID())
     return;
-  SourceLocation LParen;
   SourceLocation ArgLoc = Arg->getBeginLoc();
 
   // Special testing for the argument location.  Since the fix-it needs the
@@ -7380,14 +7381,16 @@
     ArgLoc = S.getSourceManager().getImmediateExpansionRange(ArgLoc).getBegin();
   }
 
+  SourceLocation LParen = ArgLoc.getLocWithOffset(-1);
   if (LParen.isMacroID())
     return;
-
-  LParen = ArgLoc.getLocWithOffset(-1);
+  SourceLocation EndLoc = CCE->getEndLoc();
+  if (EndLoc.isMacroID())
+    return;
 
   S.Diag(CE->getBeginLoc(), diag::note_remove_move)
-      << FixItHint::CreateRemoval(SourceRange(CallBegin, LParen))
-      << FixItHint::CreateRemoval(SourceRange(RParen, RParen));
+      << FixItHint::CreateRemoval(SourceRange(BeginLoc, LParen))
+      << FixItHint::CreateRemoval(SourceRange(RParen, EndLoc));
 }
 
 static void CheckForNullPointerDereference(Sema &S, const Expr *E) {