[wip] revert path to non-persistent list

include/klee/Expr/Path.h

@@ -7,17 +7,16 @@ DISABLE_WARNING_DEPRECATED_DECLARATIONS
 #include "llvm/Support/raw_ostream.h"
 DISABLE_WARNING_POP
 
-#include "klee/ADT/ImmutableList.h"
-
+#include <stack>
 #include <string>
 #include <vector>
 
 namespace klee {
 struct CallStackFrame;
 struct KBlock;
+struct KCallBlock;
 struct KFunction;
 struct KInstruction;
-struct KCallBlock;
 class KModule;
 
 class Path {
@@ -32,10 +31,6 @@ class Path {
       return block == other.block && kind == other.kind;
     }
 
-    bool operator!=(const entry &other) const {
-      return !(*this == other);
-    }
-
     bool operator<(const entry &other) const {
       return block < other.block || (block == other.block && kind < other.kind);
     }
@@ -44,13 +39,19 @@ class Path {
     std::vector<entry> getSuccessors();
   };
 
-  using path_ty = ImmutableList<entry>;
+  using path_ty = std::vector<entry>;
 
   struct PathIndex {
     unsigned long block;
     unsigned long instruction;
-    bool operator==(const PathIndex &rhs) const {
-      return block == rhs.block && instruction == rhs.instruction;
+
+    bool operator==(const PathIndex &other) const {
+      return block == other.block && instruction == other.instruction;
+    }
+
+    bool operator<(const PathIndex &other) const {
+      return block < other.block ||
+             (block == other.block && instruction < other.instruction);
     }
   };
 
@@ -87,18 +88,18 @@ class Path {
                (lhs.last == rhs.last && lhs.next < rhs.next)))));
   }
 
-  unsigned KBlockSize() const;
   bool empty() const { return path.empty(); }
   bool emptyWithNext() const { return path.empty() && next; }
 
   std::pair<bool, KCallBlock *> fromOutTransition() const;
 
+  unsigned KBlockSize() const { return path.size(); }
   const path_ty &getBlocks() const;
   unsigned getFirstIndex() const;
   KInstruction *getFirstInstruction() const;
+  unsigned getLastIndex() const;
   KInstruction *getLastInstruction() const;
   KInstruction *getNext() const { return next; }
-  unsigned getLastIndex() const;
 
   bool blockCompleted(unsigned index) const;
   KFunction *getCalledFunction(unsigned index) const;
@@ -114,15 +115,15 @@ class Path {
 
   static Path concat(const Path &l, const Path &r);
 
-  // static Path parse(const std::string &str, const KModule &km);
-
+  // For proof obligations
   Path() = default;
 
+  // For execution states
   explicit Path(KInstruction *next) : next(next) {}
 
-  Path(unsigned first, ImmutableList<entry> path, unsigned last,
+  Path(unsigned first, std::vector<entry> path, unsigned last,
        KInstruction *next)
-  : first(first), last(last), path(path), next(next) {}
+      : first(first), last(last), path(path), next(next) {}
 
 private:
   // The path is stored as:

lib/Core/EventRecorder.h

@@ -10,6 +10,7 @@
 #define KLEE_EVENT_RECORDER_H
 
 #include "klee/Expr/Path.h"
+#include <klee/ADT/ImmutableList.h>
 
 namespace klee {
 

lib/Expr/Parser.cpp

@@ -471,7 +471,7 @@ DeclResult ParserImpl::ParseArrayDecl() {
 Path ParserImpl::ParsePathDecl() {
   unsigned first = 0;
   unsigned last = 0;
-  ImmutableList<Path::entry> blocks;
+  std::vector<Path::entry> blocks;
   KInstruction *next = nullptr;
 
   ConsumeExpectedToken(Token::KWPath);

lib/Expr/Path.cpp

@@ -7,6 +7,7 @@
 DISABLE_WARNING_PUSH
 DISABLE_WARNING_DEPRECATED_DECLARATIONS
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Casting.h"
 DISABLE_WARNING_POP
 
 using namespace klee;
@@ -116,7 +117,7 @@ std::vector<CallStackFrame> Path::getStack(bool reversed) const {
   std::vector<CallStackFrame> stack;
   for (unsigned i = 0; i < path.size(); i++) {
     auto index = reversed ? path.size() - 1 - i : i;
-    auto current = path.at(index);
+    auto current = path[index];
 
     if (i == 0) {
       stack.push_back(CallStackFrame(nullptr, current.block->parent));
@@ -184,6 +185,8 @@ Path Path::concat(const Path &l, const Path &r) {
   }
   Path path;
   auto leftWhole = l.blockCompleted(l.path.size() - 1);
+  path.path.reserve(leftWhole ? l.path.size() + r.path.size()
+                              : l.path.size() + r.path.size() - 1);
   for (unsigned i = 0; i < l.path.size(); i++) {
     path.path.push_back(l.path.at(i));
   }
@@ -266,10 +269,6 @@ void Path::print(llvm::raw_ostream &ss) const {
   ss << ") @ " << (next ? next->toString() : "None");
 }
 
-unsigned Path::KBlockSize() const {
-  return path.size();
-}
-
 std::pair<bool, KCallBlock *> Path::fromOutTransition() const {
   if (path.empty()) {
     return {false, nullptr};