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

4 files changed, 8 insertions, 9 deletions

diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
index 1580c777ea4..b52d623b948 100644
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -1057,7 +1057,7 @@ llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
     SelValue = llvm::GlobalAlias::create(
         SelectorTy, llvm::GlobalValue::PrivateLinkage,
         ".objc_selector_" + Sel.getAsString(), &TheModule);
-    Types.push_back(TypedSelector(TypeEncoding, SelValue));
+    Types.emplace_back(TypeEncoding, SelValue);
   }
 
   if (lval) {
@@ -2121,9 +2121,8 @@ void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
   // Get the class declaration for which the alias is specified.
   ObjCInterfaceDecl *ClassDecl =
     const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
-  std::string ClassName = ClassDecl->getNameAsString();
-  std::string AliasName = OAD->getNameAsString();
-  ClassAliases.push_back(ClassAliasPair(ClassName,AliasName));
+  ClassAliases.emplace_back(ClassDecl->getNameAsString(),
+                            OAD->getNameAsString());
 }
 
 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index e275466ce1d..8d6930826d7 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -921,13 +921,13 @@ void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
   assert(!GV->isDeclaration() &&
          "Only globals with definition can force usage.");
-  LLVMUsed.push_back(GV);
+  LLVMUsed.emplace_back(GV);
 }
 
 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
   assert(!GV->isDeclaration() &&
          "Only globals with definition can force usage.");
-  LLVMCompilerUsed.push_back(GV);
+  LLVMCompilerUsed.emplace_back(GV);
 }
 
 static void emitUsed(CodeGenModule &CGM, StringRef Name,
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 35000964b2e..edde426e923 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -329,7 +329,7 @@ private:
   };
   std::vector<DeferredGlobal> DeferredDeclsToEmit;
   void addDeferredDeclToEmit(llvm::GlobalValue *GV, GlobalDecl GD) {
-    DeferredDeclsToEmit.push_back(DeferredGlobal(GV, GD));
+    DeferredDeclsToEmit.emplace_back(GV, GD);
   }
 
   /// List of alias we have emitted. Used to make sure that what they point to
@@ -876,7 +876,7 @@ public:
 
   /// Add a destructor and object to add to the C++ global destructor function.
   void AddCXXDtorEntry(llvm::Constant *DtorFn, llvm::Constant *Object) {
-    CXXGlobalDtors.push_back(std::make_pair(DtorFn, Object));
+    CXXGlobalDtors.emplace_back(DtorFn, Object);
   }
 
   /// Create a new runtime function with the specified type and name.
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 53154b513eb..af3f06e7aac 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -6741,7 +6741,7 @@ static bool extractFieldType(SmallVectorImpl<FieldEncoding> &FE,
     if (Field->isBitField())
       Enc += ')';
     Enc += '}';
-    FE.push_back(FieldEncoding(!Field->getName().empty(), Enc));
+    FE.emplace_back(!Field->getName().empty(), Enc);
   }
   return true;
 }