MFC 261991:

Upgrade our copy of llvm/clang to 3.4 release.  This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC 262121 (by emaste):

Update lldb for clang/llvm 3.4 import

This commit largely restores the lldb source to the upstream r196259
snapshot with the addition of threaded inferior support and a few bug
fixes.

Specific upstream lldb revisions restored include:
   SVN      git
  181387  779e6ac
  181703  7bef4e2
  182099  b31044e
  182650  f2dcf35
  182683  0d91b80
  183862  15c1774
  183929  99447a6
  184177  0b2934b
  184948  4dc3761
  184954  007e7bc
  186990  eebd175

Sponsored by:	DARPA, AFRL

MFC 262186 (by emaste):

Fix mismerge in r262121

A break statement was lost in the merge.  The error had no functional
impact, but restore it to reduce the diff against upstream.

MFC 262303:

Pull in r197521 from upstream clang trunk (by rdivacky):

  Use the integrated assembler by default on FreeBSD/ppc and ppc64.

Requested by:	jhibbits

MFC 262611:

Pull in r196874 from upstream llvm trunk:

  Fix a crash that occurs when PWD is invalid.

  MCJIT needs to be able to run in hostile environments, even when PWD
  is invalid. There's no need to crash MCJIT in this case.

  The obvious fix is to simply leave MCContext's CompilationDir empty
  when PWD can't be determined. This way, MCJIT clients,
  and other clients that link with LLVM don't need a valid working directory.

  If we do want to guarantee valid CompilationDir, that should be done
  only for clients of getCompilationDir(). This is as simple as checking
  for an empty string.

  The only current use of getCompilationDir is EmitGenDwarfInfo, which
  won't conceivably run with an invalid working dir. However, in the
  purely hypothetically and untestable case that this happens, the
  AT_comp_dir will be omitted from the compilation_unit DIE.

This should help fix assertions occurring with ports-mgmt/tinderbox,
when it is using jails, and sometimes invalidates clang's current
working directory.

Reported by:	decke

MFC 262809:

Pull in r203007 from upstream clang trunk:

  Don't produce an alias between destructors with different calling conventions.

  Fixes pr19007.

(Please note that is an LLVM PR identifier, not a FreeBSD one.)

This should fix Firefox and/or libxul crashes (due to problems with
regparm/stdcall calling conventions) on i386.

Reported by:	multiple users on freebsd-current
PR:		bin/187103

MFC 263048:

Repair recognition of "CC" as an alias for the C++ compiler, since it
was silently broken by upstream for a Windows-specific use-case.

Apparently some versions of CMake still rely on this archaic feature...

Reported by:	rakuco

MFC 263049:

Garbage collect the old way of adding the libstdc++ include directories
in clang's InitHeaderSearch.cpp.  This has been superseded by David
Chisnall's commit in r255321.

Moreover, if libc++ is used, the libstdc++ include directories should
not be in the search path at all.  These directories are now only used
if you pass -stdlib=libstdc++.

1 files changed, 250 insertions, 22 deletions

diff --git a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 9188945..835f643 100644
--- a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -1,4 +1,4 @@
-//===-- SelectionDAGBuilder.h - Selection-DAG building --------------------===//
+//===-- SelectionDAGBuilder.h - Selection-DAG building --------*- C++ -*---===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -26,6 +26,7 @@
 
 namespace llvm {
 
+class AddrSpaceCastInst;
 class AliasAnalysis;
 class AllocaInst;
 class BasicBlock;
@@ -80,11 +81,11 @@ class ZExtInst;
 /// implementation that is parameterized by a TargetLowering object.
 ///
 class SelectionDAGBuilder {
-  /// CurDebugLoc - current file + line number.  Changes as we build the DAG.
-  DebugLoc CurDebugLoc;
+  /// CurInst - The current instruction being visited
+  const Instruction *CurInst;
 
   DenseMap<const Value*, SDValue> NodeMap;
-  
+
   /// UnusedArgNodeMap - Maps argument value for unused arguments. This is used
   /// to preserve debug information for incoming arguments.
   DenseMap<const Value*, SDValue> UnusedArgNodeMap;
@@ -182,6 +183,17 @@ private:
 
   typedef std::vector<CaseRec> CaseRecVector;
 
+  /// The comparison function for sorting the switch case values in the vector.
+  /// WARNING: Case ranges should be disjoint!
+  struct CaseCmp {
+    bool operator()(const Case &C1, const Case &C2) {
+      assert(isa<ConstantInt>(C1.Low) && isa<ConstantInt>(C2.High));
+      const ConstantInt* CI1 = cast<const ConstantInt>(C1.Low);
+      const ConstantInt* CI2 = cast<const ConstantInt>(C2.High);
+      return CI1->getValue().slt(CI2->getValue());
+    }
+  };
+
   struct CaseBitsCmp {
     bool operator()(const CaseBits &C1, const CaseBits &C2) {
       return C1.Bits > C2.Bits;
@@ -224,7 +236,7 @@ private:
   struct JumpTable {
     JumpTable(unsigned R, unsigned J, MachineBasicBlock *M,
               MachineBasicBlock *D): Reg(R), JTI(J), MBB(M), Default(D) {}
-  
+
     /// Reg - the virtual register containing the index of the jump table entry
     //. to jump to.
     unsigned Reg;
@@ -278,12 +290,204 @@ private:
     BitTestInfo Cases;
   };
 
-public:
-  // TLI - This is information that describes the available target features we
-  // need for lowering.  This indicates when operations are unavailable,
-  // implemented with a libcall, etc.
+  /// A class which encapsulates all of the information needed to generate a
+  /// stack protector check and signals to isel via its state being initialized
+  /// that a stack protector needs to be generated.
+  ///
+  /// *NOTE* The following is a high level documentation of SelectionDAG Stack
+  /// Protector Generation. The reason that it is placed here is for a lack of
+  /// other good places to stick it.
+  ///
+  /// High Level Overview of SelectionDAG Stack Protector Generation:
+  ///
+  /// Previously, generation of stack protectors was done exclusively in the
+  /// pre-SelectionDAG Codegen LLVM IR Pass "Stack Protector". This necessitated
+  /// splitting basic blocks at the IR level to create the success/failure basic
+  /// blocks in the tail of the basic block in question. As a result of this,
+  /// calls that would have qualified for the sibling call optimization were no
+  /// longer eligible for optimization since said calls were no longer right in
+  /// the "tail position" (i.e. the immediate predecessor of a ReturnInst
+  /// instruction).
+  ///
+  /// Then it was noticed that since the sibling call optimization causes the
+  /// callee to reuse the caller's stack, if we could delay the generation of
+  /// the stack protector check until later in CodeGen after the sibling call
+  /// decision was made, we get both the tail call optimization and the stack
+  /// protector check!
+  ///
+  /// A few goals in solving this problem were:
+  ///
+  ///   1. Preserve the architecture independence of stack protector generation.
+  ///
+  ///   2. Preserve the normal IR level stack protector check for platforms like
+  ///      OpenBSD for which we support platform specific stack protector
+  ///      generation.
+  ///
+  /// The main problem that guided the present solution is that one can not
+  /// solve this problem in an architecture independent manner at the IR level
+  /// only. This is because:
+  ///
+  ///   1. The decision on whether or not to perform a sibling call on certain
+  ///      platforms (for instance i386) requires lower level information
+  ///      related to available registers that can not be known at the IR level.
+  ///
+  ///   2. Even if the previous point were not true, the decision on whether to
+  ///      perform a tail call is done in LowerCallTo in SelectionDAG which
+  ///      occurs after the Stack Protector Pass. As a result, one would need to
+  ///      put the relevant callinst into the stack protector check success
+  ///      basic block (where the return inst is placed) and then move it back
+  ///      later at SelectionDAG/MI time before the stack protector check if the
+  ///      tail call optimization failed. The MI level option was nixed
+  ///      immediately since it would require platform specific pattern
+  ///      matching. The SelectionDAG level option was nixed because
+  ///      SelectionDAG only processes one IR level basic block at a time
+  ///      implying one could not create a DAG Combine to move the callinst.
+  ///
+  /// To get around this problem a few things were realized:
+  ///
+  ///   1. While one can not handle multiple IR level basic blocks at the
+  ///      SelectionDAG Level, one can generate multiple machine basic blocks
+  ///      for one IR level basic block. This is how we handle bit tests and
+  ///      switches.
+  ///
+  ///   2. At the MI level, tail calls are represented via a special return
+  ///      MIInst called "tcreturn". Thus if we know the basic block in which we
+  ///      wish to insert the stack protector check, we get the correct behavior
+  ///      by always inserting the stack protector check right before the return
+  ///      statement. This is a "magical transformation" since no matter where
+  ///      the stack protector check intrinsic is, we always insert the stack
+  ///      protector check code at the end of the BB.
+  ///
+  /// Given the aforementioned constraints, the following solution was devised:
+  ///
+  ///   1. On platforms that do not support SelectionDAG stack protector check
+  ///      generation, allow for the normal IR level stack protector check
+  ///      generation to continue.
+  ///
+  ///   2. On platforms that do support SelectionDAG stack protector check
+  ///      generation:
+  ///
+  ///     a. Use the IR level stack protector pass to decide if a stack
+  ///        protector is required/which BB we insert the stack protector check
+  ///        in by reusing the logic already therein. If we wish to generate a
+  ///        stack protector check in a basic block, we place a special IR
+  ///        intrinsic called llvm.stackprotectorcheck right before the BB's
+  ///        returninst or if there is a callinst that could potentially be
+  ///        sibling call optimized, before the call inst.
+  ///
+  ///     b. Then when a BB with said intrinsic is processed, we codegen the BB
+  ///        normally via SelectBasicBlock. In said process, when we visit the
+  ///        stack protector check, we do not actually emit anything into the
+  ///        BB. Instead, we just initialize the stack protector descriptor
+  ///        class (which involves stashing information/creating the success
+  ///        mbbb and the failure mbb if we have not created one for this
+  ///        function yet) and export the guard variable that we are going to
+  ///        compare.
+  ///
+  ///     c. After we finish selecting the basic block, in FinishBasicBlock if
+  ///        the StackProtectorDescriptor attached to the SelectionDAGBuilder is
+  ///        initialized, we first find a splice point in the parent basic block
+  ///        before the terminator and then splice the terminator of said basic
+  ///        block into the success basic block. Then we code-gen a new tail for
+  ///        the parent basic block consisting of the two loads, the comparison,
+  ///        and finally two branches to the success/failure basic blocks. We
+  ///        conclude by code-gening the failure basic block if we have not
+  ///        code-gened it already (all stack protector checks we generate in
+  ///        the same function, use the same failure basic block).
+  class StackProtectorDescriptor {
+  public:
+    StackProtectorDescriptor() : ParentMBB(0), SuccessMBB(0), FailureMBB(0),
+                                 Guard(0) { }
+    ~StackProtectorDescriptor() { }
+
+    /// Returns true if all fields of the stack protector descriptor are
+    /// initialized implying that we should/are ready to emit a stack protector.
+    bool shouldEmitStackProtector() const {
+      return ParentMBB && SuccessMBB && FailureMBB && Guard;
+    }
+
+    /// Initialize the stack protector descriptor structure for a new basic
+    /// block.
+    void initialize(const BasicBlock *BB,
+                    MachineBasicBlock *MBB,
+                    const CallInst &StackProtCheckCall) {
+      // Make sure we are not initialized yet.
+      assert(!shouldEmitStackProtector() && "Stack Protector Descriptor is "
+             "already initialized!");
+      ParentMBB = MBB;
+      SuccessMBB = AddSuccessorMBB(BB, MBB);
+      FailureMBB = AddSuccessorMBB(BB, MBB, FailureMBB);
+      if (!Guard)
+        Guard = StackProtCheckCall.getArgOperand(0);
+    }
+
+    /// Reset state that changes when we handle different basic blocks.
+    ///
+    /// This currently includes:
+    ///
+    /// 1. The specific basic block we are generating a
+    /// stack protector for (ParentMBB).
+    ///
+    /// 2. The successor machine basic block that will contain the tail of
+    /// parent mbb after we create the stack protector check (SuccessMBB). This
+    /// BB is visited only on stack protector check success.
+    void resetPerBBState() {
+      ParentMBB = 0;
+      SuccessMBB = 0;
+    }
+
+    /// Reset state that only changes when we switch functions.
+    ///
+    /// This currently includes:
+    ///
+    /// 1. FailureMBB since we reuse the failure code path for all stack
+    /// protector checks created in an individual function.
+    ///
+    /// 2.The guard variable since the guard variable we are checking against is
+    /// always the same.
+    void resetPerFunctionState() {
+      FailureMBB = 0;
+      Guard = 0;
+    }
+
+    MachineBasicBlock *getParentMBB() { return ParentMBB; }
+    MachineBasicBlock *getSuccessMBB() { return SuccessMBB; }
+    MachineBasicBlock *getFailureMBB() { return FailureMBB; }
+    const Value *getGuard() { return Guard; }
+
+  private:
+    /// The basic block for which we are generating the stack protector.
+    ///
+    /// As a result of stack protector generation, we will splice the
+    /// terminators of this basic block into the successor mbb SuccessMBB and
+    /// replace it with a compare/branch to the successor mbbs
+    /// SuccessMBB/FailureMBB depending on whether or not the stack protector
+    /// was violated.
+    MachineBasicBlock *ParentMBB;
+
+    /// A basic block visited on stack protector check success that contains the
+    /// terminators of ParentMBB.
+    MachineBasicBlock *SuccessMBB;
+
+    /// This basic block visited on stack protector check failure that will
+    /// contain a call to __stack_chk_fail().
+    MachineBasicBlock *FailureMBB;
+
+    /// The guard variable which we will compare against the stored value in the
+    /// stack protector stack slot.
+    const Value *Guard;
+
+    /// Add a successor machine basic block to ParentMBB. If the successor mbb
+    /// has not been created yet (i.e. if SuccMBB = 0), then the machine basic
+    /// block will be created.
+    MachineBasicBlock *AddSuccessorMBB(const BasicBlock *BB,
+                                       MachineBasicBlock *ParentMBB,
+                                       MachineBasicBlock *SuccMBB = 0);
+  };
+
+private:
   const TargetMachine &TM;
-  const TargetLowering &TLI;
+public:
   SelectionDAG &DAG;
   const DataLayout *TD;
   AliasAnalysis *AA;
@@ -298,6 +502,9 @@ public:
   /// BitTestCases - Vector of BitTestBlock structures used to communicate
   /// SwitchInst code generation information.
   std::vector<BitTestBlock> BitTestCases;
+  /// A StackProtectorDescriptor structure used to communicate stack protector
+  /// information in between SelectBasicBlock and FinishBasicBlock.
+  StackProtectorDescriptor SPDescriptor;
 
   // Emit PHI-node-operand constants only once even if used by multiple
   // PHI nodes.
@@ -308,9 +515,9 @@ public:
   FunctionLoweringInfo &FuncInfo;
 
   /// OptLevel - What optimization level we're generating code for.
-  /// 
+  ///
   CodeGenOpt::Level OptLevel;
-  
+
   /// GFI - Garbage collection metadata for the function.
   GCFunctionInfo *GFI;
 
@@ -327,7 +534,7 @@ public:
 
   SelectionDAGBuilder(SelectionDAG &dag, FunctionLoweringInfo &funcinfo,
                       CodeGenOpt::Level ol)
-    : SDNodeOrder(0), TM(dag.getTarget()), TLI(dag.getTargetLoweringInfo()),
+    : CurInst(NULL), SDNodeOrder(0), TM(dag.getTarget()),
       DAG(dag), FuncInfo(funcinfo), OptLevel(ol),
       HasTailCall(false) {
   }
@@ -364,17 +571,18 @@ public:
   ///
   SDValue getControlRoot();
 
-  DebugLoc getCurDebugLoc() const { return CurDebugLoc; }
+  SDLoc getCurSDLoc() const {
+    return SDLoc(CurInst, SDNodeOrder);
+  }
+
+  DebugLoc getCurDebugLoc() const {
+    return CurInst ? CurInst->getDebugLoc() : DebugLoc();
+  }
 
   unsigned getSDNodeOrder() const { return SDNodeOrder; }
 
   void CopyValueToVirtualRegister(const Value *V, unsigned Reg);
 
-  /// AssignOrderingToNode - Assign an ordering to the node. The order is gotten
-  /// from how the code appeared in the source. The ordering is used by the
-  /// scheduler to effectively turn off scheduling.
-  void AssignOrderingToNode(const SDNode *Node);
-
   void visit(const Instruction &I);
 
   void visit(unsigned Opcode, const User &I);
@@ -391,7 +599,7 @@ public:
     assert(N.getNode() == 0 && "Already set a value for this node!");
     N = NewN;
   }
-  
+
   void setUnusedArgValue(const Value *V, SDValue NewN) {
     SDValue &N = UnusedArgNodeMap[V];
     assert(N.getNode() == 0 && "Already set a value for this node!");
@@ -412,6 +620,12 @@ public:
   void LowerCallTo(ImmutableCallSite CS, SDValue Callee, bool IsTailCall,
                    MachineBasicBlock *LandingPad = NULL);
 
+  std::pair<SDValue, SDValue> LowerCallOperands(const CallInst &CI,
+                                                unsigned ArgIdx,
+                                                unsigned NumArgs,
+                                                SDValue Callee,
+                                                bool useVoidTy = false);
+
   /// UpdateSplitBlock - When an MBB was split during scheduling, update the
   /// references that ned to refer to the last resulting block.
   void UpdateSplitBlock(MachineBasicBlock *First, MachineBasicBlock *Last);
@@ -453,6 +667,9 @@ private:
 public:
   void visitSwitchCase(CaseBlock &CB,
                        MachineBasicBlock *SwitchBB);
+  void visitSPDescriptorParent(StackProtectorDescriptor &SPD,
+                               MachineBasicBlock *ParentBB);
+  void visitSPDescriptorFailure(StackProtectorDescriptor &SPD);
   void visitBitTestHeader(BitTestBlock &B, MachineBasicBlock *SwitchBB);
   void visitBitTestCase(BitTestBlock &BB,
                         MachineBasicBlock* NextMBB,
@@ -463,7 +680,7 @@ public:
   void visitJumpTable(JumpTable &JT);
   void visitJumpTableHeader(JumpTable &JT, JumpTableHeader &JTH,
                             MachineBasicBlock *SwitchBB);
-  
+
 private:
   // These all get lowered before this pass.
   void visitInvoke(const InvokeInst &I);
@@ -504,6 +721,7 @@ private:
   void visitPtrToInt(const User &I);
   void visitIntToPtr(const User &I);
   void visitBitCast(const User &I);
+  void visitAddrSpaceCast(const User &I);
 
   void visitExtractElement(const User &I);
   void visitInsertElement(const User &I);
@@ -525,6 +743,11 @@ private:
   void visitPHI(const PHINode &I);
   void visitCall(const CallInst &I);
   bool visitMemCmpCall(const CallInst &I);
+  bool visitMemChrCall(const CallInst &I);
+  bool visitStrCpyCall(const CallInst &I, bool isStpcpy);
+  bool visitStrCmpCall(const CallInst &I);
+  bool visitStrLenCall(const CallInst &I);
+  bool visitStrNLenCall(const CallInst &I);
   bool visitUnaryFloatCall(const CallInst &I, unsigned Opcode);
   void visitAtomicLoad(const LoadInst &I);
   void visitAtomicStore(const StoreInst &I);
@@ -537,6 +760,8 @@ private:
   void visitVAArg(const VAArgInst &I);
   void visitVAEnd(const CallInst &I);
   void visitVACopy(const CallInst &I);
+  void visitStackmap(const CallInst &I);
+  void visitPatchpoint(const CallInst &I);
 
   void visitUserOp1(const Instruction &I) {
     llvm_unreachable("UserOp1 should not exist at instruction selection time!");
@@ -545,10 +770,13 @@ private:
     llvm_unreachable("UserOp2 should not exist at instruction selection time!");
   }
 
+  void processIntegerCallValue(const Instruction &I,
+                               SDValue Value, bool IsSigned);
+
   void HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB);
 
   /// EmitFuncArgumentDbgValue - If V is an function argument then create
-  /// corresponding DBG_VALUE machine instruction for it now. At the end of 
+  /// corresponding DBG_VALUE machine instruction for it now. At the end of
   /// instruction selection, they will be inserted to the entry BB.
   bool EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
                                 int64_t Offset, const SDValue &N);