Adds a C++05 version of unique_ptr. Used this to solve a garbage collection problem caused by memory leaks of heap allocated Parsers.

3 files changed, 82 insertions, 14 deletions

diff --git a/src/base/Makefile.am b/src/base/Makefile.am
index bda063176..94e45c542 100644
--- a/src/base/Makefile.am
+++ b/src/base/Makefile.am
@@ -20,6 +20,7 @@ libbase_la_SOURCES = \
 	configuration_private.h \
 	cvc4_assert.cpp \
 	cvc4_assert.h \
+	cvc4_unique_ptr.h \
 	exception.cpp \
 	exception.h \
 	listener.cpp \
diff --git a/src/base/cvc4_unique_ptr.h b/src/base/cvc4_unique_ptr.h
new file mode 100644
index 000000000..9642d0185
--- /dev/null
+++ b/src/base/cvc4_unique_ptr.h
@@ -0,0 +1,70 @@
+/*********************                                                        */
+/*! \file cvc4_unique_ptr.h
+ ** \verbatim
+ ** Top contributors (to current version):
+ **   Tim King
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
+ ** in the top-level source directory) and their institutional affiliations.
+ ** All rights reserved.  See the file COPYING in the top-level source
+ ** directory for licensing information.\endverbatim
+ **
+ ** \brief A CVC4 variant of unique_ptr for C++05.
+ **
+ ** A CVC4 variant of unique_ptr for C++05.
+ **/
+
+#include "cvc4_public.h"
+
+#ifndef __CVC4__UNIQUE_PTR_H
+#define __CVC4__UNIQUE_PTR_H
+
+namespace CVC4 {
+
+/**
+ * A CVC4 variant of unique_ptr for C++05.
+ *
+ * This is a variant of unique_ptr that is not designed for move semantics.
+ * These are appropriate to own pointer allocations on the stack that should be
+ * deleted when an exception is thrown. These should be used with care within
+ * heap based data structures, and never as the return value of a function.
+ */
+template <class T>
+class UniquePtr {
+ public:
+  UniquePtr() : d_pointer(NULL) {}
+  UniquePtr(T* pointer) : d_pointer(pointer) {}
+  ~UniquePtr() { delete d_pointer; }
+
+  void reset(T* pointer) {
+    delete d_pointer;
+    d_pointer = pointer;
+  }
+
+  /** Gives up ownership of the pointer to the caller. */
+  T* release() {
+    T* copy = d_pointer;
+    d_pointer = NULL;
+    return copy;
+  }
+
+  /** Returns the pointer. */
+  T* get() const { return d_pointer; }
+
+  /** Returns the pointer. Undefined if the pointer is null. */
+  T* operator->() const { return d_pointer; }
+
+  /** Returns true if the pointer is not-null. */
+  operator bool() const { return d_pointer != NULL; }
+
+ private:
+  UniquePtr(const UniquePtr*) CVC4_UNDEFINED;
+  UniquePtr& operator=(const UniquePtr&) CVC4_UNDEFINED;
+
+  /** An owned pointer object allocated by `new` or NULL. */
+  T* d_pointer;
+}; /* class UniquePtr */
+
+} /* CVC4 namespace */
+
+#endif /* __CVC4__UNIQUE_PTR_H */
diff --git a/src/main/driver_unified.cpp b/src/main/driver_unified.cpp
index bab70e98f..e9e703b5f 100644
--- a/src/main/driver_unified.cpp
+++ b/src/main/driver_unified.cpp
@@ -26,6 +26,7 @@
 #include "cvc4autoconfig.h"
 
 #include "base/configuration.h"
+#include "base/cvc4_unique_ptr.h"
 #include "base/output.h"
 #include "expr/expr_iomanip.h"
 #include "expr/expr_manager.h"
@@ -241,7 +242,7 @@ int runCvc4(int argc, char* argv[], Options& opts) {
   }
 # endif
 
-  Parser* replayParser = NULL;
+  UniquePtr<Parser> replayParser;
   if( opts.getReplayInputFilename() != "" ) {
     std::string replayFilename = opts.getReplayInputFilename();
     ParserBuilder replayParserBuilder(exprMgr, replayFilename, opts);
@@ -252,8 +253,8 @@ int runCvc4(int argc, char* argv[], Options& opts) {
       }
       replayParserBuilder.withStreamInput(cin);
     }
-    replayParser = replayParserBuilder.build();
-    pExecutor->setReplayStream(new Parser::ExprStream(replayParser));
+    replayParser.reset(replayParserBuilder.build());
+    pExecutor->setReplayStream(new Parser::ExprStream(replayParser.get()));
   }
 
   int returnValue = 0;
@@ -297,7 +298,7 @@ int runCvc4(int argc, char* argv[], Options& opts) {
                   << (Configuration::isAssertionBuild() ? "on" : "off")
                   << endl;
       }
-      if(replayParser != NULL) {
+      if(replayParser) {
         // have the replay parser use the declarations input interactively
         replayParser->useDeclarationsFrom(shell.getParser());
       }
@@ -347,10 +348,10 @@ int runCvc4(int argc, char* argv[], Options& opts) {
 
       vector< vector<Command*> > allCommands;
       allCommands.push_back(vector<Command*>());
-      Parser *parser = parserBuilder.build();
-      if(replayParser != NULL) {
+      UniquePtr<Parser> parser(parserBuilder.build());
+      if(replayParser) {
         // have the replay parser use the file's declarations
-        replayParser->useDeclarationsFrom(parser);
+        replayParser->useDeclarationsFrom(parser.get());
       }
       int needReset = 0;
       // true if one of the commands was interrupted
@@ -484,8 +485,6 @@ int runCvc4(int argc, char* argv[], Options& opts) {
         }
         delete cmd;
       }
-      // Remove the parser
-      delete parser;
     } else {
       if(!opts.wasSetByUserIncrementalSolving()) {
         cmd = new SetOptionCommand("incremental", SExpr(false));
@@ -504,10 +503,10 @@ int runCvc4(int argc, char* argv[], Options& opts) {
 #endif /* CVC4_COMPETITION_MODE && !CVC4_SMTCOMP_APPLICATION_TRACK */
       }
 
-      Parser *parser = parserBuilder.build();
-      if(replayParser != NULL) {
+      UniquePtr<Parser> parser(parserBuilder.build());
+      if(replayParser) {
         // have the replay parser use the file's declarations
-        replayParser->useDeclarationsFrom(parser);
+        replayParser->useDeclarationsFrom(parser.get());
       }
       bool interrupted = false;
       while(status || opts.getContinuedExecution()) {
@@ -536,8 +535,6 @@ int runCvc4(int argc, char* argv[], Options& opts) {
         }
         delete cmd;
       }
-      // Remove the parser
-      delete parser;
     }
 
     Result result;