pgr_assert.h File Reference

An assert functionality that uses C++ throw(). More...

#include <string>
#include <exception>

Include dependency graph for pgr_assert.h:

Go to the source code of this file.

Classes
class	AssertFailedException
	Extends std::exception and is the exception that we throw if an assert fails. More...

Macros
#define	__STRING(x)   #x
#define	__TOSTRING(x)   __STRING(x)
#define	pgassert(expr)
	Uses the standard assert syntax. More...
#define	pgassertwm(expr, msg)
	Adds a message to the assertion. More...

Functions
std::string	get_backtrace ()
	returns the execution path of the trace More...
std::string	get_backtrace (const std::string &)

Detailed Description

An assert functionality that uses C++ throw().

Assertions Handling

This file provides an alternative to assert functionality that will convert all pgassert() into C++ throw using an AssertFailedException class.

This allows catching errors and do appropriate clean up re-throw if needed to catch errors in the postgresql environment

Do not crash the backend server.

Definition in file pgr_assert.h.

Macro Definition Documentation

__STRING

#define __STRING

(

x

)

#x

Definition at line 55 of file pgr_assert.h.

__TOSTRING

#define __TOSTRING

(

x

)

__STRING(x)

Definition at line 58 of file pgr_assert.h.

pgassert

#define pgassert

(

expr

)

Value:

    ((expr) \
     ? static_cast<void>(0) \
     : throw AssertFailedException( \
         "AssertFailedException: " __STRING(expr) \
         " at " __FILE__ ":" __TOSTRING(__LINE__) + get_backtrace() ) )

Uses the standard assert syntax.

When an assertion fails it will throw AssertFailedException and what() will return a string like "AssertFailedException(2+2 == 5) at t.cpp:11"

Example:

#include <iostream>
#include "pgr_assert.h"
 
int main() {
 
    try {
        pgassert(2+2 == 4);
        pgassert(2+2 == 5);
    }
    catch (AssertFailedException &e) {
        std::cout << e.what() << "\n";
    }
    catch (std::exception& e) {
        std::cout << e.what() << "\n";
    }
    catch(...) {
        std::cout << "Caught unknown exception!\n";
    }
    return 0;
}

Definition at line 94 of file pgr_assert.h.

pgassertwm

#define pgassertwm	(		expr,
			msg
	)

Value:

    ((expr) \
     ? static_cast<void>(0) \
     : throw AssertFailedException( \
         "AssertFailedException: " __STRING(expr) \
         " at " __FILE__ ":" __TOSTRING(__LINE__) + get_backtrace(msg) ) )

Adds a message to the assertion.

Example:

pgassert(2+2 == 5, "Expected a 4 as result");
std::ostringstream log;
log << "Expected a 4 as result"
pgassert(2+2 == 5, log.str());

Definition at line 117 of file pgr_assert.h.

Function Documentation

get_backtrace() [1/2]

std::string get_backtrace

(

)

returns the execution path of the trace

In case of a failed exception the backtrace can be is shown in the error message.

Does not work for windows, please read: http://stackoverflow.com/questions/27639931/can-not-find-execinfo-h-when-setup-malpack

Definition at line 40 of file pgr_assert.cpp.

                          {
#ifdef __GLIBC__
        void *trace[16];
        int i, trace_size = 0;
 
        trace_size = backtrace(trace, 16);
        char** funcNames = backtrace_symbols(trace, trace_size);
 
 
        std::string message = "\n*** Execution path***\n";
        for (i = 0; i < trace_size; ++i) {
            message += "[bt]" + static_cast<std::string>(funcNames[i]) + "\n";
        }
 
        free(funcNames);
        return message;
#else
        return "";
#endif
}

Referenced by get_backtrace().

get_backtrace() [2/2]

std::string get_backtrace

(

const std::string &

)

Definition at line 61 of file pgr_assert.cpp.

                                              {
    return std::string("\n") + msg + "\n" + get_backtrace();
}

References get_backtrace().