1 files changed, 332 insertions, 0 deletions

diff --git a/contrib/llvm-project/clang/lib/Analysis/ThreadSafetyTIL.cpp b/contrib/llvm-project/clang/lib/Analysis/ThreadSafetyTIL.cpp
new file mode 100644
index 000000000000..652f953d2a6d
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/Analysis/ThreadSafetyTIL.cpp
@@ -0,0 +1,332 @@
+//===- ThreadSafetyTIL.cpp ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
+#include "clang/Basic/LLVM.h"
+#include "llvm/Support/Casting.h"
+#include <cassert>
+#include <cstddef>
+
+using namespace clang;
+using namespace threadSafety;
+using namespace til;
+
+StringRef til::getUnaryOpcodeString(TIL_UnaryOpcode Op) {
+  switch (Op) {
+    case UOP_Minus:    return "-";
+    case UOP_BitNot:   return "~";
+    case UOP_LogicNot: return "!";
+  }
+  return {};
+}
+
+StringRef til::getBinaryOpcodeString(TIL_BinaryOpcode Op) {
+  switch (Op) {
+    case BOP_Mul:      return "*";
+    case BOP_Div:      return "/";
+    case BOP_Rem:      return "%";
+    case BOP_Add:      return "+";
+    case BOP_Sub:      return "-";
+    case BOP_Shl:      return "<<";
+    case BOP_Shr:      return ">>";
+    case BOP_BitAnd:   return "&";
+    case BOP_BitXor:   return "^";
+    case BOP_BitOr:    return "|";
+    case BOP_Eq:       return "==";
+    case BOP_Neq:      return "!=";
+    case BOP_Lt:       return "<";
+    case BOP_Leq:      return "<=";
+    case BOP_Cmp:      return "<=>";
+    case BOP_LogicAnd: return "&&";
+    case BOP_LogicOr:  return "||";
+  }
+  return {};
+}
+
+SExpr* Future::force() {
+  Status = FS_evaluating;
+  Result = compute();
+  Status = FS_done;
+  return Result;
+}
+
+unsigned BasicBlock::addPredecessor(BasicBlock *Pred) {
+  unsigned Idx = Predecessors.size();
+  Predecessors.reserveCheck(1, Arena);
+  Predecessors.push_back(Pred);
+  for (auto *E : Args) {
+    if (auto *Ph = dyn_cast<Phi>(E)) {
+      Ph->values().reserveCheck(1, Arena);
+      Ph->values().push_back(nullptr);
+    }
+  }
+  return Idx;
+}
+
+void BasicBlock::reservePredecessors(unsigned NumPreds) {
+  Predecessors.reserve(NumPreds, Arena);
+  for (auto *E : Args) {
+    if (auto *Ph = dyn_cast<Phi>(E)) {
+      Ph->values().reserve(NumPreds, Arena);
+    }
+  }
+}
+
+// If E is a variable, then trace back through any aliases or redundant
+// Phi nodes to find the canonical definition.
+const SExpr *til::getCanonicalVal(const SExpr *E) {
+  while (true) {
+    if (const auto *V = dyn_cast<Variable>(E)) {
+      if (V->kind() == Variable::VK_Let) {
+        E = V->definition();
+        continue;
+      }
+    }
+    if (const auto *Ph = dyn_cast<Phi>(E)) {
+      if (Ph->status() == Phi::PH_SingleVal) {
+        E = Ph->values()[0];
+        continue;
+      }
+    }
+    break;
+  }
+  return E;
+}
+
+// If E is a variable, then trace back through any aliases or redundant
+// Phi nodes to find the canonical definition.
+// The non-const version will simplify incomplete Phi nodes.
+SExpr *til::simplifyToCanonicalVal(SExpr *E) {
+  while (true) {
+    if (auto *V = dyn_cast<Variable>(E)) {
+      if (V->kind() != Variable::VK_Let)
+        return V;
+      // Eliminate redundant variables, e.g. x = y, or x = 5,
+      // but keep anything more complicated.
+      if (til::ThreadSafetyTIL::isTrivial(V->definition())) {
+        E = V->definition();
+        continue;
+      }
+      return V;
+    }
+    if (auto *Ph = dyn_cast<Phi>(E)) {
+      if (Ph->status() == Phi::PH_Incomplete)
+        simplifyIncompleteArg(Ph);
+      // Eliminate redundant Phi nodes.
+      if (Ph->status() == Phi::PH_SingleVal) {
+        E = Ph->values()[0];
+        continue;
+      }
+    }
+    return E;
+  }
+}
+
+// Trace the arguments of an incomplete Phi node to see if they have the same
+// canonical definition.  If so, mark the Phi node as redundant.
+// getCanonicalVal() will recursively call simplifyIncompletePhi().
+void til::simplifyIncompleteArg(til::Phi *Ph) {
+  assert(Ph && Ph->status() == Phi::PH_Incomplete);
+
+  // eliminate infinite recursion -- assume that this node is not redundant.
+  Ph->setStatus(Phi::PH_MultiVal);
+
+  SExpr *E0 = simplifyToCanonicalVal(Ph->values()[0]);
+  for (unsigned i = 1, n = Ph->values().size(); i < n; ++i) {
+    SExpr *Ei = simplifyToCanonicalVal(Ph->values()[i]);
+    if (Ei == Ph)
+      continue;  // Recursive reference to itself.  Don't count.
+    if (Ei != E0) {
+      return;    // Status is already set to MultiVal.
+    }
+  }
+  Ph->setStatus(Phi::PH_SingleVal);
+}
+
+// Renumbers the arguments and instructions to have unique, sequential IDs.
+unsigned BasicBlock::renumberInstrs(unsigned ID) {
+  for (auto *Arg : Args)
+    Arg->setID(this, ID++);
+  for (auto *Instr : Instrs)
+    Instr->setID(this, ID++);
+  TermInstr->setID(this, ID++);
+  return ID;
+}
+
+// Sorts the CFGs blocks using a reverse post-order depth-first traversal.
+// Each block will be written into the Blocks array in order, and its BlockID
+// will be set to the index in the array.  Sorting should start from the entry
+// block, and ID should be the total number of blocks.
+unsigned BasicBlock::topologicalSort(SimpleArray<BasicBlock *> &Blocks,
+                                     unsigned ID) {
+  if (Visited) return ID;
+  Visited = true;
+  for (auto *Block : successors())
+    ID = Block->topologicalSort(Blocks, ID);
+  // set ID and update block array in place.
+  // We may lose pointers to unreachable blocks.
+  assert(ID > 0);
+  BlockID = --ID;
+  Blocks[BlockID] = this;
+  return ID;
+}
+
+// Performs a reverse topological traversal, starting from the exit block and
+// following back-edges.  The dominator is serialized before any predecessors,
+// which guarantees that all blocks are serialized after their dominator and
+// before their post-dominator (because it's a reverse topological traversal).
+// ID should be initially set to 0.
+//
+// This sort assumes that (1) dominators have been computed, (2) there are no
+// critical edges, and (3) the entry block is reachable from the exit block
+// and no blocks are accessible via traversal of back-edges from the exit that
+// weren't accessible via forward edges from the entry.
+unsigned BasicBlock::topologicalFinalSort(SimpleArray<BasicBlock *> &Blocks,
+                                          unsigned ID) {
+  // Visited is assumed to have been set by the topologicalSort.  This pass
+  // assumes !Visited means that we've visited this node before.
+  if (!Visited) return ID;
+  Visited = false;
+  if (DominatorNode.Parent)
+    ID = DominatorNode.Parent->topologicalFinalSort(Blocks, ID);
+  for (auto *Pred : Predecessors)
+    ID = Pred->topologicalFinalSort(Blocks, ID);
+  assert(static_cast<size_t>(ID) < Blocks.size());
+  BlockID = ID++;
+  Blocks[BlockID] = this;
+  return ID;
+}
+
+// Computes the immediate dominator of the current block.  Assumes that all of
+// its predecessors have already computed their dominators.  This is achieved
+// by visiting the nodes in topological order.
+void BasicBlock::computeDominator() {
+  BasicBlock *Candidate = nullptr;
+  // Walk backwards from each predecessor to find the common dominator node.
+  for (auto *Pred : Predecessors) {
+    // Skip back-edges
+    if (Pred->BlockID >= BlockID) continue;
+    // If we don't yet have a candidate for dominator yet, take this one.
+    if (Candidate == nullptr) {
+      Candidate = Pred;
+      continue;
+    }
+    // Walk the alternate and current candidate back to find a common ancestor.
+    auto *Alternate = Pred;
+    while (Alternate != Candidate) {
+      if (Candidate->BlockID > Alternate->BlockID)
+        Candidate = Candidate->DominatorNode.Parent;
+      else
+        Alternate = Alternate->DominatorNode.Parent;
+    }
+  }
+  DominatorNode.Parent = Candidate;
+  DominatorNode.SizeOfSubTree = 1;
+}
+
+// Computes the immediate post-dominator of the current block.  Assumes that all
+// of its successors have already computed their post-dominators.  This is
+// achieved visiting the nodes in reverse topological order.
+void BasicBlock::computePostDominator() {
+  BasicBlock *Candidate = nullptr;
+  // Walk back from each predecessor to find the common post-dominator node.
+  for (auto *Succ : successors()) {
+    // Skip back-edges
+    if (Succ->BlockID <= BlockID) continue;
+    // If we don't yet have a candidate for post-dominator yet, take this one.
+    if (Candidate == nullptr) {
+      Candidate = Succ;
+      continue;
+    }
+    // Walk the alternate and current candidate back to find a common ancestor.
+    auto *Alternate = Succ;
+    while (Alternate != Candidate) {
+      if (Candidate->BlockID < Alternate->BlockID)
+        Candidate = Candidate->PostDominatorNode.Parent;
+      else
+        Alternate = Alternate->PostDominatorNode.Parent;
+    }
+  }
+  PostDominatorNode.Parent = Candidate;
+  PostDominatorNode.SizeOfSubTree = 1;
+}
+
+// Renumber instructions in all blocks
+void SCFG::renumberInstrs() {
+  unsigned InstrID = 0;
+  for (auto *Block : Blocks)
+    InstrID = Block->renumberInstrs(InstrID);
+}
+
+static inline void computeNodeSize(BasicBlock *B,
+                                   BasicBlock::TopologyNode BasicBlock::*TN) {
+  BasicBlock::TopologyNode *N = &(B->*TN);
+  if (N->Parent) {
+    BasicBlock::TopologyNode *P = &(N->Parent->*TN);
+    // Initially set ID relative to the (as yet uncomputed) parent ID
+    N->NodeID = P->SizeOfSubTree;
+    P->SizeOfSubTree += N->SizeOfSubTree;
+  }
+}
+
+static inline void computeNodeID(BasicBlock *B,
+                                 BasicBlock::TopologyNode BasicBlock::*TN) {
+  BasicBlock::TopologyNode *N = &(B->*TN);
+  if (N->Parent) {
+    BasicBlock::TopologyNode *P = &(N->Parent->*TN);
+    N->NodeID += P->NodeID;    // Fix NodeIDs relative to starting node.
+  }
+}
+
+// Normalizes a CFG.  Normalization has a few major components:
+// 1) Removing unreachable blocks.
+// 2) Computing dominators and post-dominators
+// 3) Topologically sorting the blocks into the "Blocks" array.
+void SCFG::computeNormalForm() {
+  // Topologically sort the blocks starting from the entry block.
+  unsigned NumUnreachableBlocks = Entry->topologicalSort(Blocks, Blocks.size());
+  if (NumUnreachableBlocks > 0) {
+    // If there were unreachable blocks shift everything down, and delete them.
+    for (unsigned I = NumUnreachableBlocks, E = Blocks.size(); I < E; ++I) {
+      unsigned NI = I - NumUnreachableBlocks;
+      Blocks[NI] = Blocks[I];
+      Blocks[NI]->BlockID = NI;
+      // FIXME: clean up predecessor pointers to unreachable blocks?
+    }
+    Blocks.drop(NumUnreachableBlocks);
+  }
+
+  // Compute dominators.
+  for (auto *Block : Blocks)
+    Block->computeDominator();
+
+  // Once dominators have been computed, the final sort may be performed.
+  unsigned NumBlocks = Exit->topologicalFinalSort(Blocks, 0);
+  assert(static_cast<size_t>(NumBlocks) == Blocks.size());
+  (void) NumBlocks;
+
+  // Renumber the instructions now that we have a final sort.
+  renumberInstrs();
+
+  // Compute post-dominators and compute the sizes of each node in the
+  // dominator tree.
+  for (auto *Block : Blocks.reverse()) {
+    Block->computePostDominator();
+    computeNodeSize(Block, &BasicBlock::DominatorNode);
+  }
+  // Compute the sizes of each node in the post-dominator tree and assign IDs in
+  // the dominator tree.
+  for (auto *Block : Blocks) {
+    computeNodeID(Block, &BasicBlock::DominatorNode);
+    computeNodeSize(Block, &BasicBlock::PostDominatorNode);
+  }
+  // Assign IDs in the post-dominator tree.
+  for (auto *Block : Blocks.reverse()) {
+    computeNodeID(Block, &BasicBlock::PostDominatorNode);
+  }
+}