DbC

Design-by-Contract module for C/C++. More...

Modules
	DbC-DEM
	The following macros are an approximation to implement a Disciplined Exception Mechanism using only the language preprocessor.

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

Data Structures
struct	DbC_Error
	DbC exceptions throw a pointer to this structure. More...

Macros
#define	PRECONDITION_ERROR
	Integer value for a precondition error code.
#define	POSTCONDITION_ERROR
	Integer value for a postcondition error code.
#define	INVARIANT_ERROR
	Integer value for an invariant error code.
#define	CHECK_ERROR
	Integer value for a check error code.
#define	check(condition, message)
	Checks the verification of an general algorithm assertion.
#define	require(condition, message)
	Checks the verification of a precondition.
#define	ensure(condition, message)
	Checks the verification of a postcondition.
#define	invariant(condition, message)
	Checks the verification of an invariant.
#define	IS_DbC_ERROR(e)
	checks if it is a DbC error code
#define	DbC_ERROR_2_STR(e)
	Converts DbC error code to a string.

Detailed Description

Design-by-Contract module for C/C++.

This module gives an alternative 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 (through the definition of a macro – EXIT_POLICY/EXCEPTION_POLICY – as a compiler option):
  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 DbC_Error* 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

Date

2018, 2026

Version

1.1

Macro Definition Documentation

check

#define check	(		condition,
			message
	)

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

require

#define require	(		condition,
			message
	)

Checks the verification of a precondition.

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

Parameters

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

ensure

#define ensure	(		condition,
			message
	)

Checks the verification of a postcondition.

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

Parameters

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

invariant

#define invariant	(		condition,
			message
	)

Checks the verification of an invariant.

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

Parameters

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

IS_DbC_ERROR

#define IS_DbC_ERROR

(

e

)

checks if it is a DbC error code

Parameters

[in]

e

[int] integer error value

Returns

true if value is a DbC error

DbC_ERROR_2_STR

#define DbC_ERROR_2_STR

(

e

)

Converts DbC error code to a string.

Parameters

[in]

e

[int] integer error value

Returns

the result string