From: Akira Hatanaka Date: Sat, 15 Apr 2017 06:42:00 +0000 (+0000) Subject: [ObjC] Use empty Objective-C collection literal constants when X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6b1aefd5a606e04df91f9f29d80e28b428ff8b4b;p=clang [ObjC] Use empty Objective-C collection literal constants when available. Original patch by Douglas Gregor with minor modifications. This recommits r300389, which broke bots because there have been API changes since the original patch was written. rdar://problem/20689633 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300396 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Basic/ObjCRuntime.h b/include/clang/Basic/ObjCRuntime.h index 78fc899882..8dc259c7ab 100644 --- a/include/clang/Basic/ObjCRuntime.h +++ b/include/clang/Basic/ObjCRuntime.h @@ -326,6 +326,20 @@ public: } } + /// Are the empty collection symbols available? + bool hasEmptyCollections() const { + switch (getKind()) { + default: + return false; + case MacOSX: + return getVersion() >= VersionTuple(10, 11); + case iOS: + return getVersion() >= VersionTuple(9); + case WatchOS: + return getVersion() >= VersionTuple(2); + } + } + /// \brief Try to parse an Objective-C runtime specification from the given /// string. /// diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp index c011ab4dfc..3a09a15dbc 100644 --- a/lib/CodeGen/CGObjC.cpp +++ b/lib/CodeGen/CGObjC.cpp @@ -117,10 +117,22 @@ llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E, const ObjCArrayLiteral *ALE = dyn_cast(E); if (!ALE) DLE = cast(E); - - // Compute the type of the array we're initializing. + + // Optimize empty collections by referencing constants, when available. uint64_t NumElements = ALE ? ALE->getNumElements() : DLE->getNumElements(); + if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) { + StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__"; + QualType IdTy(CGM.getContext().getObjCIdType()); + llvm::Constant *Constant = + CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName); + Address Addr(Constant, Context.getTypeAlignInChars(IdTy)); + LValue LV = MakeAddrLValue(Addr, IdTy); + return Builder.CreateBitCast(EmitLoadOfScalar(LV, E->getLocStart()), + ConvertType(E->getType())); + } + + // Compute the type of the array we're initializing. llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()), NumElements); QualType ElementType = Context.getObjCIdType().withConst(); diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp index 485d012b6e..d65570fcef 100644 --- a/lib/Sema/SemaExprCXX.cpp +++ b/lib/Sema/SemaExprCXX.cpp @@ -5980,9 +5980,21 @@ ExprResult Sema::MaybeBindToTemporary(Expr *E) { } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast(E)) { D = BoxedExpr->getBoxingMethod(); } else if (ObjCArrayLiteral *ArrayLit = dyn_cast(E)) { + // Don't do reclaims if we're using the zero-element array + // constant. + if (ArrayLit->getNumElements() == 0 && + Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) + return E; + D = ArrayLit->getArrayWithObjectsMethod(); } else if (ObjCDictionaryLiteral *DictLit = dyn_cast(E)) { + // Don't do reclaims if we're using the zero-element dictionary + // constant. + if (DictLit->getNumElements() == 0 && + Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) + return E; + D = DictLit->getDictWithObjectsMethod(); } diff --git a/test/CodeGenObjC/empty-collection-literals.m b/test/CodeGenObjC/empty-collection-literals.m new file mode 100644 index 0000000000..0f9715f521 --- /dev/null +++ b/test/CodeGenObjC/empty-collection-literals.m @@ -0,0 +1,51 @@ +// RUN: %clang_cc1 -I %S/Inputs -triple x86_64-apple-macosx10.10.0 -fobjc-runtime=macosx-10.10.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITHOUT-EMPTY-COLLECTIONS %s +// RUN: %clang_cc1 -I %S/Inputs -triple x86_64-apple-macosx10.11.0 -fobjc-runtime=macosx-10.11.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITH-EMPTY-COLLECTIONS %s + +// RUN: %clang_cc1 -I %S/Inputs -triple arm64-apple-ios8.0 -fobjc-runtime=ios-8.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITHOUT-EMPTY-COLLECTIONS %s +// RUN: %clang_cc1 -I %S/Inputs -triple arm64-apple-ios9.0 -fobjc-runtime=ios-9.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITH-EMPTY-COLLECTIONS %s + +// RUN: %clang_cc1 -I %S/Inputs -triple armv7k-apple-watchos2.0 -fobjc-runtime=watchos-1.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITHOUT-EMPTY-COLLECTIONS %s +// RUN: %clang_cc1 -I %S/Inputs -triple armv7k-apple-watchos2.0 -fobjc-runtime=watchos-2.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITH-EMPTY-COLLECTIONS %s + +// RUN: %clang_cc1 -I %S/Inputs -triple arm64-apple-tvos8.0 -fobjc-runtime=ios-8.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITHOUT-EMPTY-COLLECTIONS %s +// RUN: %clang_cc1 -I %S/Inputs -triple arm64-apple-tvos9.0 -fobjc-runtime=ios-9.0 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=CHECK-WITH-EMPTY-COLLECTIONS %s + +#include "literal-support.h" + +void test_empty_array() { + // CHECK-WITHOUT-EMPTY-COLLECTIONS-LABEL: define void @test_empty_array + // CHECK-WITHOUT-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITHOUT-EMPTY-COLLECTIONS: {{call.*objc_msgSend}} + // CHECK-WITHOUT-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITHOUT-EMPTY-COLLECTIONS: {{call.*objc_retainAutoreleasedReturnValue}} + // CHECK-WITHOUT-EMPTY-COLLECTIONS: ret void + + // CHECK-WITH-EMPTY-COLLECTIONS-LABEL: define void @test_empty_array + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: load {{.*}} @__NSArray0__ + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: {{call.*objc_retain\(}} + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: call void @objc_storeStrong + // CHECK-WITH-EMPTY-COLLECTIONS-NEXT: ret void + NSArray *arr = @[]; +} + +void test_empty_dictionary() { + // CHECK-WITHOUT-EMPTY-COLLECTIONS-LABEL: define void @test_empty_dictionary + // CHECK-WITHOUT-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITHOUT-EMPTY-COLLECTIONS: {{call.*objc_msgSend}} + // CHECK-WITHOUT-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITHOUT-EMPTY-COLLECTIONS: {{call.*objc_retainAutoreleasedReturnValue}} + // CHECK-WITHOUT-EMPTY-COLLECTIONS: ret void + + // CHECK-WITH-EMPTY-COLLECTIONS-LABEL: define void @test_empty_dictionary + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: load {{.*}} @__NSDictionary0__ + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: {{call.*objc_retain\(}} + // CHECK-WITH-EMPTY-COLLECTIONS-NOT: ret void + // CHECK-WITH-EMPTY-COLLECTIONS: call void @objc_storeStrong + // CHECK-WITH-EMPTY-COLLECTIONS-NEXT: ret void + NSDictionary *dict = @{}; +}