Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types

If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

llvm-svn: 238601

1 files changed, 3 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 5e3a8279504..609c25da3eb 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4514,16 +4514,15 @@ bool ASTReader::ParseHeaderSearchOptions(const RecordData &Record,
       = static_cast<frontend::IncludeDirGroup>(Record[Idx++]);
     bool IsFramework = Record[Idx++];
     bool IgnoreSysRoot = Record[Idx++];
-    HSOpts.UserEntries.push_back(
-      HeaderSearchOptions::Entry(Path, Group, IsFramework, IgnoreSysRoot));
+    HSOpts.UserEntries.emplace_back(std::move(Path), Group, IsFramework,
+                                    IgnoreSysRoot);
   }
 
   // System header prefixes.
   for (unsigned N = Record[Idx++]; N; --N) {
     std::string Prefix = ReadString(Record, Idx);
     bool IsSystemHeader = Record[Idx++];
-    HSOpts.SystemHeaderPrefixes.push_back(
-      HeaderSearchOptions::SystemHeaderPrefix(Prefix, IsSystemHeader));
+    HSOpts.SystemHeaderPrefixes.emplace_back(std::move(Prefix), IsSystemHeader);
   }
 
   HSOpts.ResourceDir = ReadString(Record, Idx);