commit 1e36882b5291d5a7209be4f9c99b9713828afac4
author Erik Pilkington <erik.pilkington@gmail.com> Fri Jan 04 18:33:06 2019 +0000
committer Erik Pilkington <erik.pilkington@gmail.com> Fri Jan 04 18:33:06 2019 +0000
tree cd23171fec5d69fd0390b0ad9303f51396072b5c
parent 6153565511338f33506f4615dd5a7d2e4c4ffaa6

[ObjCARC] Add an new attribute, objc_externally_retained

This attribute, called "objc_externally_retained", exposes clang's
notion of pseudo-__strong variables in ARC. Pseudo-strong variables
"borrow" their initializer, meaning that they don't retain/release
it, instead assuming that someone else is keeping their value alive.

If a function is annotated with this attribute, implicitly strong
parameters of that function aren't implicitly retained/released in
the function body, and are implicitly const. This is useful to expose
for performance reasons, most functions don't need the extra safety
of the retain/release, so programmers can opt out as needed.

This attribute can also apply to declarations of local variables,
with similar effect.

Differential revision: https://reviews.llvm.org/D55865

llvm-svn: 350422

clang/lib/Serialization/ASTReaderDecl.cpp

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 8c1710f..763ab52 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1350,6 +1350,7 @@
   VD->VarDeclBits.SClass = (StorageClass)Record.readInt();
   VD->VarDeclBits.TSCSpec = Record.readInt();
   VD->VarDeclBits.InitStyle = Record.readInt();
+  VD->VarDeclBits.ARCPseudoStrong = Record.readInt();
   if (!isa<ParmVarDecl>(VD)) {
     VD->NonParmVarDeclBits.IsThisDeclarationADemotedDefinition =
         Record.readInt();
@@ -1357,7 +1358,6 @@
     VD->NonParmVarDeclBits.NRVOVariable = Record.readInt();
     VD->NonParmVarDeclBits.CXXForRangeDecl = Record.readInt();
     VD->NonParmVarDeclBits.ObjCForDecl = Record.readInt();
-    VD->NonParmVarDeclBits.ARCPseudoStrong = Record.readInt();
     VD->NonParmVarDeclBits.IsInline = Record.readInt();
     VD->NonParmVarDeclBits.IsInlineSpecified = Record.readInt();
     VD->NonParmVarDeclBits.IsConstexpr = Record.readInt();

clang/lib/Serialization/ASTWriterDecl.cpp

diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 5ec11dd..002b43f 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -922,13 +922,13 @@
   Record.push_back(D->getStorageClass());
   Record.push_back(D->getTSCSpec());
   Record.push_back(D->getInitStyle());
+  Record.push_back(D->isARCPseudoStrong());
   if (!isa<ParmVarDecl>(D)) {
     Record.push_back(D->isThisDeclarationADemotedDefinition());
     Record.push_back(D->isExceptionVariable());
     Record.push_back(D->isNRVOVariable());
     Record.push_back(D->isCXXForRangeDecl());
     Record.push_back(D->isObjCForDecl());
-    Record.push_back(D->isARCPseudoStrong());
     Record.push_back(D->isInline());
     Record.push_back(D->isInlineSpecified());
     Record.push_back(D->isConstexpr());
@@ -1986,6 +1986,7 @@
   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
+  Abv->Add(BitCodeAbbrevOp(0));                       // ARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
@@ -2062,12 +2063,12 @@
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr