Fix issue #7 : SQLITECPP_ENABLE_ASSERT_HANDLER

- SQLITECPP_ASSERT() can call a user defined SQLite::assertion_failed() handler.

CMakeLists.txt

@@ -16,6 +16,9 @@ if (SQLITE_ENABLE_COLUMN_METADATA)
   add_definitions(-DSQLITE_ENABLE_COLUMN_METADATA)
 endif()
 
+add_definitions(-DSQLITECPP_ENABLE_ASSERT_HANDLER)
+  
+
 if (MSVC)
   # build the SQLite3 C library for Windows (for ease of use)
   add_subdirectory (sqlite3) 

README.md

@@ -205,6 +205,25 @@ catch (std::exception& e)
 }
 ```
 
+### How to handle in assertion in SQLiteC++:
+Exceptions shall not be used in destructors, so SQLiteC++ use SQLITECPP_ASSERT() to check for errors in destructors.
+If you don't want assert() to be called, you have to enable and define an assert handler as shown below.
+
+```C++
+#ifdef SQLITECPP_ENABLE_ASSERT_HANDLER
+namespace SQLite
+{
+/// definition of the assertion handler enabled when SQLITECPP_ENABLE_ASSERT_HANDLER is defined in the project (CMakeList.txt)
+void assertion_failed(const char* apFile, const long apLine, const char* apFunc, const char* apExpr, const char* apMsg)
+{
+    // Print a message to the standard error output stream, and abort the program.
+    std::cerr << apFile << ":" << apLine << ":" << " error: assertion (" << apExpr << ") failed in '" << apFunc << "' (" << apMsg << ")\n";
+    std::abort();
+}
+}
+#endif
+```
+
 ## How to contribute
 ### GitHub website
 The most efficient way to help and contribute to this wrapper project is to

examples/example1/main.cpp

@@ -14,10 +14,25 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+
 #include "../../src/SQLiteC++.h"
 
+#ifdef SQLITECPP_ENABLE_ASSERT_HANDLER
+namespace SQLite
+{
+/// definition of the assertion handler enabled when SQLITECPP_ENABLE_ASSERT_HANDLER is defined in the project (CMakeList.txt)
+void assertion_failed(const char* apFile, const long apLine, const char* apFunc, const char* apExpr, const char* apMsg)
+{
+    // Print a message to the standard error output stream, and abort the program.
+    std::cerr << apFile << ":" << apLine << ":" << " error: assertion (" << apExpr << ") failed in " << apFunc << ": '" << apMsg << "'\n";
+    std::abort();
+}
+}
+#endif
 
+/// Example Database
 static const char* filename_example_db3 = "examples/example1/example.db3";
+/// Image
 static const char* filename_logo_png    = "examples/example1/logo.png";
 
 
@@ -107,7 +122,6 @@ int main (void)
             }
 #endif
             std::cout << "row (" << id << ", \"" << value2.c_str() << "\" "  << bytes << " bytes, " << weight << ")\n";
-
         }
 
         // Reset the query to use it again
@@ -327,7 +341,7 @@ int main (void)
                 size = colBlob.getBytes ();
                 std::cout << "row (" << query.getColumn(0) << ", size=" << size << ")\n";
                 size_t sizew = fwrite(blob, 1, size, fp);
-                SQLITE_CPP_ASSERT(sizew == size);
+                SQLITECPP_ASSERT(sizew == size, "fwrite failed");   // See SQLITECPP_ENABLE_ASSERT_HANDLER
                 fclose (fp);
             }
         }

src/Assert.h

@@ -0,0 +1,56 @@
+/**
+ * @file    Assert.h
+ * @ingroup SQLiteCpp
+ * @brief   Definition of the SQLITECPP_ASSERT() macro.
+ *
+ * Copyright (c) 2012-2013 Sebastien Rombauts (sebastien.rombauts@gmail.com)
+ *
+ * Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
+ * or copy at http://opensource.org/licenses/MIT)
+ */
+#pragma once
+
+#include <cassert>
+
+
+/**
+ * @def SQLITECPP_ASSERT SQLITECPP_ASSERT() is used in destructors, where exceptions shall not be thrown
+ *
+ * Define SQLITECPP_ENABLE_ASSERT_HANDLER at the project level
+ * and define a SQLite::assertion_failed() assertion handler
+ * to tell SQLiteC++ to use it instead of assert() when an assertion fail.
+*/
+#ifdef SQLITECPP_ENABLE_ASSERT_HANDLER
+
+// if an assert handler is provided by user code, use it instead of assert()
+namespace SQLite
+{
+    // declaration of the assert handler to define in user code
+    void assertion_failed(const char* apFile, const long apLine, const char* apFunc, const char* apExpr, const char* apMsg);
+
+#ifdef _MSC_VER
+    #define __func__ __FUNCTION__
+#endif
+// call the assert handler provided by user code
+#define SQLITECPP_ASSERT(expression,message) \
+    if (!(expression))  SQLite::assertion_failed(__FILE__, __LINE__, __func__, #expression, message)
+}
+
+#else
+
+// if no assert handler provided by user code, use standard assert()
+
+#ifndef NDEBUG
+    // in debug mode, assert() :
+    #define SQLITECPP_ASSERT(expression,message) assert(expression)
+#else
+    // in release mode, nothing :
+    #define SQLITECPP_ASSERT(expression,message) (expression)
+#endif
+
+#endif
+
+
+#ifdef _WIN32
+#pragma warning(disable:4290) // Disable warning C4290: C++ exception specification ignored except to indicate a function is not __declspec(nothrow)
+#endif

src/CMakeLists.txt

@@ -12,6 +12,7 @@
 # add sources of the wrapper as a "SQLiteCpp" static library
 add_library (SQLiteCpp
  SQLiteC++.h
+ Assert.h
  Column.cpp
  Column.h
  Database.cpp

src/Database.cpp

@@ -11,6 +11,7 @@
 #include "Database.h"
 
 #include "Statement.h"
+#include "Assert.h"
 #include "Exception.h"
 
 
@@ -37,8 +38,7 @@ Database::~Database(void) throw() // nothrow
 {
     int ret = sqlite3_close(mpSQLite);
     // Never throw an exception in a destructor
-    //std::cout << sqlite3_errmsg(mpSQLite) << std::endl;
-    SQLITE_CPP_ASSERT (SQLITE_OK == ret);
+    SQLITECPP_ASSERT (SQLITE_OK == ret, sqlite3_errmsg(mpSQLite));  // See SQLITECPP_ENABLE_ASSERT_HANDLER
 }
 
 // Shortcut to execute one or multiple SQL statements without results (UPDATE, INSERT, ALTER, COMMIT...).

src/Exception.h

@@ -11,23 +11,6 @@
 #pragma once
 
 #include <stdexcept>
-#include <cassert>
-
-
-// assert() is used in destructors, where exceptions are not allowed
-// here you can chose if you want to use them or not
-#ifndef NDEBUG
-    // in debug mode :
-    #define SQLITE_CPP_ASSERT(expression) assert(expression)
-#else
-    // in release mode :
-    #define SQLITE_CPP_ASSERT(expression) (expression)
-#endif
-
-
-#ifdef _WIN32
-#pragma warning(disable:4290) // Disable warning C4290: C++ exception specification ignored except to indicate a function is not __declspec(nothrow)
-#endif
 
 
 namespace SQLite

src/SQLiteC++.h

@@ -18,6 +18,7 @@
 
 
 // Include useful headers of SQLiteC++
+#include "Assert.h"
 #include "Exception.h"
 #include "Database.h"
 #include "Statement.h"

src/Statement.cpp

@@ -12,6 +12,7 @@
 
 #include "Database.h"
 #include "Column.h"
+#include "Assert.h"
 #include "Exception.h"
 
 
@@ -316,8 +317,7 @@ Statement::Ptr::~Ptr(void) throw() // nothrow
         // as no Statement not Column objet use it anymore
         int ret = sqlite3_finalize(mpStmt);
         // Never throw an exception in a destructor
-        //std::cout << sqlite3_errmsg(mpSQLite) << std::endl;
-        SQLITE_CPP_ASSERT (SQLITE_OK == ret);
+        SQLITECPP_ASSERT (SQLITE_OK == ret, sqlite3_errmsg(mpSQLite));  // See SQLITECPP_ENABLE_ASSERT_HANDLER
 
         // and delete the reference counter
         delete mpRefCount;

src/Transaction.cpp

@@ -11,6 +11,7 @@
 #include "Transaction.h"
 
 #include "Database.h"
+#include "Assert.h"
 #include "Exception.h"
 
 
@@ -35,11 +36,10 @@ Transaction::~Transaction(void) throw() // nothrow
         {
             mDatabase.exec("ROLLBACK");
         }
-        catch (SQLite::Exception& /*e*/)
+        catch (SQLite::Exception& e)
         {
             // Never throw an exception in a destructor
-            //std::cout << e.what() << std::endl;
-            SQLITE_CPP_ASSERT(false);
+            SQLITECPP_ASSERT(false, e.what());  // See SQLITECPP_ENABLE_ASSERT_HANDLER
         }
     }
 }