DbC

Design-by-Contract module. More...

Files
file	dbc.h
	Design-by-Contract module.

Macros
#define	check(condition, message)
	Checks the verification of an general algorithm assertion. More...
#define	require(condition, message)
	Checks the verification of a precondition. More...
#define	ensure(condition, message)
	Checks the verification of a postcondition. More...
#define	invariant(condition, message)
	Checks the verification of an invariant. More...

Detailed Description

Design-by-Contract module.

This module gives a better support for DbC in C++.

When compared with assert.h this module offers the following functionalities:

• separates different assertion types (preconditions, postconditions, invariants, and others);
• augments assert with error message strings;
• implements two error handling policies:
  1. EXIT_POLICY (default): describes the failed assertion in stderr (with the identification and the precise location of the assertion), generates a segmentation fault (enabling a stack trace within a debugger like gdb), and exits program execution;
  2. EXCEPTION_POLICY: throws a char* exception with the description of the failed assertion.

Debug settings:

• As happens with assert.h, this module accepts NDEBUG macro definition to disable all assertion run-time verification.
• Also, each assertion type verification can be disabled with macros: NDEBUG_CHECKS, NDEBUG_PRECONDITIONS, NDEBUG_POSTCONDITIONS, and NDEBUG_INVARIANTS.
• A special (high priority) macro named DEBUG_ONLY_PRECONDITIONS ensures that only precondition debugging remains active (regardless of other debug definitions).

Author

Miguel Oliveira e Silva, 2018

Macro Definition Documentation

check

#define check	(		condition,
			message
	)

Value:

if (!(condition)) \
      do { \
         fprintf (stderr, "Assertion fail%s%s, assertion: \"%s\", function: \"%s\":%d, file: \"%s\"\n", \
                  message[0] ? ": " : "", message, #condition, __FUNCTION__, __LINE__ , __FILE__); \
         *((int*)0) = 0; \
         abort (); \
      } while (0)

Checks the verification of an general algorithm assertion.

This assertion verification can be disabled at compile time by defining the macro NDEBUG_CHECKS.

Parameters

[in]	condition	expression to assert its truthness
[in]	message	text to be presented with error information when the assertion fails

require

#define require	(		condition,
			message
	)

Value:

if (!(condition)) \
      do { \
         fprintf (stderr, "Precondition fail%s%s, assertion: \"%s\", function: \"%s\":%d, file: \"%s\"\n", \
                  message[0] ? ": " : "", message, #condition, __FUNCTION__, __LINE__ , __FILE__); \
         *((int*)0) = 0; \
         abort (); \
      } while (0)

Checks the verification of a precondition.

This assertion verification can be disabled at compile time by defining the macro NDEBUG_PRECONDITIONS.

Parameters

[in]	condition	expression to assert its truthness
[in]	message	text to be presented with error information when the assertion fails

ensure

#define ensure	(		condition,
			message
	)

Value:

if (!(condition)) \
      do { \
         fprintf (stderr, "Postcondition fail%s%s, assertion: \"%s\", function: \"%s\":%d, file: \"%s\"\n", \
                  message[0] ? ": " : "", message, #condition, __FUNCTION__, __LINE__ , __FILE__); \
         *((int*)0) = 0; \
         abort (); \
      } while (0)

Checks the verification of a postcondition.

This assertion verification can be disabled at compile time by defining the macro NDEBUG_POSTCONDITIONS.

Parameters

[in]	condition	expression to assert its truthness
[in]	message	text to be presented with error information when the assertion fails

invariant

#define invariant	(		condition,
			message
	)

Value:

if (!(condition)) \
      do { \
         fprintf (stderr, "Invariant fail%s%s, assertion: \"%s\", function: \"%s\":%d, file: \"%s\"\n", \
                  message[0] ? ": " : "", message, #condition, __FUNCTION__, __LINE__ , __FILE__); \
         *((int*)0) = 0; \
         abort (); \
      } while (0)

Checks the verification of an invariant.

This assertion verification can be disabled at compile time by defining the macro NDEBUG_INVARIANTS.

Parameters

[in]	condition	expression to assert its truthness
[in]	message	text to be presented with error information when the assertion fails