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: 238602

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
index d7038fd2c9a..9e71b108280 100644
--- a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -438,7 +438,7 @@ int ExecutionEngine::runFunctionAsMain(Function *Fn,
       if (NumArgs > 2) {
         std::vector<std::string> EnvVars;
         for (unsigned i = 0; envp[i]; ++i)
-          EnvVars.push_back(envp[i]);
+          EnvVars.emplace_back(envp[i]);
         // Arg #2 = envp.
         GVArgs.push_back(PTOGV(CEnv.reset(Fn->getContext(), this, EnvVars)));
       }