From 2e00b98027b51ee5bfb88a4daea8b78bf9a01e62 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Sat, 8 Sep 2018 20:03:00 +0000 Subject: Distinguish `__block` variables that are captured by escaping blocks from those that aren't. This patch changes the way __block variables that aren't captured by escaping blocks are handled: - Since non-escaping blocks on the stack never get copied to the heap (see https://reviews.llvm.org/D49303), Sema shouldn't error out when the type of a non-escaping __block variable doesn't have an accessible copy constructor. - IRGen doesn't have to use the specialized byref structure (see https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a non-escaping __block variable anymore. Instead IRGen can emit the variable as a normal variable and copy the reference to the block literal. Byref copy/dispose helpers aren't needed either. rdar://problem/39352313 Differential Revision: https://reviews.llvm.org/D51564 llvm-svn: 341754 --- clang/lib/CodeGen/CodeGenFunction.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'clang/lib/CodeGen/CodeGenFunction.h') diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h index f56284d..0a11d04 100644 --- a/clang/lib/CodeGen/CodeGenFunction.h +++ b/clang/lib/CodeGen/CodeGenFunction.h @@ -1787,7 +1787,7 @@ public: llvm::Value *ptr); Address LoadBlockStruct(); - Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef); + Address GetAddrOfBlockDecl(const VarDecl *var); /// BuildBlockByrefAddress - Computes the location of the /// data in a variable which is declared as __block. @@ -2683,8 +2683,9 @@ public: llvm::Value *NRVOFlag; - /// True if the variable is a __block variable. - bool IsByRef; + /// True if the variable is a __block variable that is captured by an + /// escaping block. + bool IsEscapingByRef; /// True if the variable is of aggregate type and has a constant /// initializer. @@ -2704,7 +2705,7 @@ public: AutoVarEmission(const VarDecl &variable) : Variable(&variable), Addr(Address::invalid()), NRVOFlag(nullptr), - IsByRef(false), IsConstantAggregate(false), + IsEscapingByRef(false), IsConstantAggregate(false), SizeForLifetimeMarkers(nullptr), AllocaAddr(Address::invalid()) {} bool wasEmittedAsGlobal() const { return !Addr.isValid(); } @@ -2734,7 +2735,7 @@ public: /// Note that this does not chase the forwarding pointer for /// __block decls. Address getObjectAddress(CodeGenFunction &CGF) const { - if (!IsByRef) return Addr; + if (!IsEscapingByRef) return Addr; return CGF.emitBlockByrefAddress(Addr, Variable, /*forward*/ false); } -- cgit v1.1