diff options
| -rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCOpts.cpp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp index e6c5928375..8e4da2f796 100644 --- a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp +++ b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp @@ -30,6 +30,7 @@ #include "ObjCARCAliasAnalysis.h" #include "ProvenanceAnalysis.h" #include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/DenseSet.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" @@ -985,6 +986,13 @@ namespace { /// A flag indicating whether this optimization pass should run. bool Run; + /// This set contains references to objc_autorelease calls that at one point + /// in time were objc_autoreleaseRV calls. Thus we can disambiguate + /// in between objc_autorelease that were inserted from the frontend (which + /// we must be very conservative with) and those as a result of strength + /// reducing objc_autoreleaseRV calls (which are more flexible). + DenseSet<Instruction *> ImpreciseAutoreleaseSet; + /// Declarations for ObjC runtime functions, for use in creating calls to /// them. These are initialized lazily to avoid cluttering up the Module /// with unused declarations. @@ -1034,6 +1042,27 @@ namespace { bool IsRetainBlockOptimizable(const Instruction *Inst); + /// Erase an instruction. + /// + /// This is included separately from the EraseInstruction in ObjCARC.h + /// (which this uses internally) in order to make sure that state is cleaned + /// up. Currently this just means attempting to remove said instruction from + /// ImpreciseAutoreleaseSet if it is an autorelease instruction. This will + /// prevent bugs of the sort where we erase an instruction and forget to + /// remove any associated state. + /// + /// TODO: Maybe remove this, the ImpreciseAutoreleaseSet, the + /// MetadataKind/Callee variables into a separate class. + void EraseInstruction(Instruction *Inst) { + // If Inst is an autorelease instruction, erase it from + // ImpreciseAutoreleaseSet if it is contained there in. + if (GetBasicInstructionClass(Inst) == IC_Autorelease) { + ImpreciseAutoreleaseSet.erase(Inst); + } + // Invoke the normal EraseInstruction. + llvm::objcarc::EraseInstruction(Inst); + } + void OptimizeRetainCall(Function &F, Instruction *Retain); bool OptimizeRetainRVCall(Function &F, Instruction *RetainRV); void OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV, @@ -1359,6 +1388,12 @@ ObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV, AutoreleaseRVCI->setTailCall(false); // Never tail call objc_autorelease. Class = IC_Autorelease; + // Stash the given instruction in the ImpreciseAutoreleaseSet so we can check + // later on that this instruction was an autoreleaseRV instruction that was + // converted to an autorelease instead of an autorelease inserted by the + // frontend (which we can not touch). + ImpreciseAutoreleaseSet.insert(AutoreleaseRVCI); + DEBUG(dbgs() << "New: " << *AutoreleaseRV << "\n"); } @@ -3094,11 +3129,14 @@ bool ObjCARCOpt::runOnFunction(Function &F) { DEBUG(dbgs() << "\n"); + ImpreciseAutoreleaseSet.clear(); + return Changed; } void ObjCARCOpt::releaseMemory() { PA.clear(); + ImpreciseAutoreleaseSet.clear(); } /// @} |