remove klee_alias_function()

this function can be used to modify the control flow of the program
on different paths, enabling self-modifying code.

include/klee/ExecutionState.h

@@ -144,8 +144,6 @@ class ExecutionState {
   std::set<std::string> arrayNames;
 
   std::string getFnAlias(std::string fn);
-  void addFnAlias(std::string old_fn, std::string new_fn);
-  void removeFnAlias(std::string fn);
 
   // The objects handling the klee_open_merge calls this state ran through
   std::vector<ref<MergeHandler> > openMergeStack;

include/klee/klee.h

@@ -138,14 +138,6 @@ extern "C" {
   /* Enable/disable forking. */
   void klee_set_forking(unsigned enable);
 
-  /* klee_alias_function("foo", "bar") will replace, at runtime (on
-     the current path and all paths spawned on the current path), all
-     calls to foo() by calls to bar().  foo() and bar() have to exist
-     and have identical types.  Use klee_alias_function("foo", "foo")
-     to undo.  Be aware that some special functions, such as exit(),
-     may not always work. */
-  void klee_alias_function(const char* fn_name, const char* new_fn_name);
-
   /* Print stack trace. */
   void klee_stack_trace(void);
 

lib/Core/ExecutionState.cpp

@@ -173,14 +173,6 @@ std::string ExecutionState::getFnAlias(std::string fn) {
   else return "";
 }
 
-void ExecutionState::addFnAlias(std::string old_fn, std::string new_fn) {
-  fnAliases[old_fn] = new_fn;
-}
-
-void ExecutionState::removeFnAlias(std::string fn) {
-  fnAliases.erase(fn);
-}
-
 /**/
 
 llvm::raw_ostream &klee::operator<<(llvm::raw_ostream &os, const MemoryMap &mm) {

lib/Core/SpecialFunctionHandler.cpp

@@ -108,7 +108,6 @@ static SpecialFunctionHandler::HandlerInfo handlerInfo[] = {
   add("klee_stack_trace", handleStackTrace, false),
   add("klee_warning", handleWarning, false),
   add("klee_warning_once", handleWarningOnce, false),
-  add("klee_alias_function", handleAliasFunction, false),
   add("malloc", handleMalloc, true),
   add("memalign", handleMemalign, true),
   add("realloc", handleRealloc, true),
@@ -299,20 +298,6 @@ void SpecialFunctionHandler::handleSilentExit(ExecutionState &state,
   executor.terminateState(state);
 }
 
-void SpecialFunctionHandler::handleAliasFunction(ExecutionState &state,
-						 KInstruction *target,
-						 std::vector<ref<Expr> > &arguments) {
-  assert(arguments.size()==2 && 
-         "invalid number of arguments to klee_alias_function");
-  std::string old_fn = readStringAtAddress(state, arguments[0]);
-  std::string new_fn = readStringAtAddress(state, arguments[1]);
-  KLEE_DEBUG_WITH_TYPE("alias_handling", llvm::errs() << "Replacing " << old_fn
-                                           << "() with " << new_fn << "()\n");
-  if (old_fn == new_fn)
-    state.removeFnAlias(old_fn);
-  else state.addFnAlias(old_fn, new_fn);
-}
-
 void SpecialFunctionHandler::handleAssert(ExecutionState &state,
                                           KInstruction *target,
                                           std::vector<ref<Expr> > &arguments) {

lib/Core/SpecialFunctionHandler.h

@@ -111,7 +111,6 @@ namespace klee {
     HANDLER(handleDeleteArray);
     HANDLER(handleExit);
     HANDLER(handleErrnoLocation);
-    HANDLER(handleAliasFunction);
     HANDLER(handleFree);
     HANDLER(handleGetErrno);
     HANDLER(handleGetObjSize);

tools/klee/main.cpp

@@ -780,7 +780,6 @@ static const char *modelledExternals[] = {
   "klee_silent_exit",
   "klee_warning",
   "klee_warning_once",
-  "klee_alias_function",
   "klee_stack_trace",
   "llvm.dbg.declare",
   "llvm.dbg.value",