Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 122 insertions, 0 deletions

diff --git a/clang-r353983/include/clang/Analysis/Analyses/LiveVariables.h b/clang-r353983/include/clang/Analysis/Analyses/LiveVariables.h
new file mode 100644
index 00000000..a46c35ee
--- /dev/null
+++ b/clang-r353983/include/clang/Analysis/Analyses/LiveVariables.h
@@ -0,0 +1,122 @@
+//===- LiveVariables.h - Live Variable Analysis for Source CFGs -*- C++ --*-//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements Live Variables analysis for source-level CFGs.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_LIVEVARIABLES_H
+#define LLVM_CLANG_ANALYSIS_ANALYSES_LIVEVARIABLES_H
+
+#include "clang/AST/Decl.h"
+#include "clang/Analysis/AnalysisDeclContext.h"
+#include "llvm/ADT/ImmutableSet.h"
+
+namespace clang {
+
+class CFG;
+class CFGBlock;
+class Stmt;
+class DeclRefExpr;
+class SourceManager;
+
+class LiveVariables : public ManagedAnalysis {
+public:
+  class LivenessValues {
+  public:
+
+    llvm::ImmutableSet<const Stmt *> liveStmts;
+    llvm::ImmutableSet<const VarDecl *> liveDecls;
+    llvm::ImmutableSet<const BindingDecl *> liveBindings;
+
+    bool equals(const LivenessValues &V) const;
+
+    LivenessValues()
+      : liveStmts(nullptr), liveDecls(nullptr), liveBindings(nullptr) {}
+
+    LivenessValues(llvm::ImmutableSet<const Stmt *> LiveStmts,
+                   llvm::ImmutableSet<const VarDecl *> LiveDecls,
+                   llvm::ImmutableSet<const BindingDecl *> LiveBindings)
+        : liveStmts(LiveStmts), liveDecls(LiveDecls),
+          liveBindings(LiveBindings) {}
+
+    bool isLive(const Stmt *S) const;
+    bool isLive(const VarDecl *D) const;
+
+    friend class LiveVariables;
+  };
+
+  class Observer {
+    virtual void anchor();
+  public:
+    virtual ~Observer() {}
+
+    /// A callback invoked right before invoking the
+    ///  liveness transfer function on the given statement.
+    virtual void observeStmt(const Stmt *S,
+                             const CFGBlock *currentBlock,
+                             const LivenessValues& V) {}
+
+    /// Called when the live variables analysis registers
+    /// that a variable is killed.
+    virtual void observerKill(const DeclRefExpr *DR) {}
+  };
+
+  ~LiveVariables() override;
+
+  /// Compute the liveness information for a given CFG.
+  static LiveVariables *computeLiveness(AnalysisDeclContext &analysisContext,
+                                        bool killAtAssign);
+
+  /// Return true if a variable is live at the end of a
+  /// specified block.
+  bool isLive(const CFGBlock *B, const VarDecl *D);
+
+  /// Returns true if a variable is live at the beginning of the
+  ///  the statement.  This query only works if liveness information
+  ///  has been recorded at the statement level (see runOnAllBlocks), and
+  ///  only returns liveness information for block-level expressions.
+  bool isLive(const Stmt *S, const VarDecl *D);
+
+  /// Returns true the block-level expression "value" is live
+  ///  before the given block-level expression (see runOnAllBlocks).
+  bool isLive(const Stmt *Loc, const Stmt *StmtVal);
+
+  /// Print to stderr the variable liveness information associated with
+  /// each basic block.
+  void dumpBlockLiveness(const SourceManager &M);
+
+  /// Print to stderr the statement liveness information associated with
+  /// each basic block.
+  void dumpStmtLiveness(const SourceManager &M);
+
+  void runOnAllBlocks(Observer &obs);
+
+  static LiveVariables *create(AnalysisDeclContext &analysisContext) {
+    return computeLiveness(analysisContext, true);
+  }
+
+  static const void *getTag();
+
+private:
+  LiveVariables(void *impl);
+  void *impl;
+};
+
+class RelaxedLiveVariables : public LiveVariables {
+public:
+  static LiveVariables *create(AnalysisDeclContext &analysisContext) {
+    return computeLiveness(analysisContext, false);
+  }
+
+  static const void *getTag();
+};
+
+} // end namespace clang
+
+#endif