bsls_preconditions

Macros
#define	BSLS_PRECONDITIONS_BEGIN_IMP()
#define	BSLS_PRECONDITIONS_END_IMP()
#define	BSLS_PRECONDITIONS_BEGIN()   do {} while(false)
#define	BSLS_PRECONDITIONS_END()   do {} while(false)

Detailed Description

Outline

• Purpose
• Classes
• Macros
• Description
  • Usage

Purpose

Provide macros for use in fuzz testing narrow contract functions.

Classes

• bsls::PreconditionsHandler: for begin/end callback management functions

Macros

• BSLS_PRECONDITIONS_BEGIN: mark the start of function preconditions
• BSLS_PRECONDITIONS_END: mark the end of function preconditions

See also

bsls_fuzztest

Description

This component provides macros, BSLS_PRECONDITIONS_BEGIN and BSLS_PRECONDITIONS_END, to facilitate fuzz testing narrow contract functions. When fuzz testing is not enabled, the macros expand to nothing. When fuzz testing is enabled, the macros invoke a dynamic handler function via bsls::PreconditionsHandler.

BSLS_PRECONDITIONS_BEGIN is used as a marker to identify where precondition checks are begun, while BSLS_PRECONDITIONS_END is used as a marker to identify where precondition checks are complete. These macros should always be used as a pair, and always at the very beginning of a function, surrounding the function preconditions.

Usage

Since the macros contained in this component are intended to be used in conjunction with the macros defined in bsls_fuzztest , this test driver contains only the simplest USAGE EXAMPLE. See the USAGE EXAMPLE in bsls_fuzztest for a fuller treatment.

The following example shows the use of BSLS_PRECONDITIONS_BEGIN and BSLS_PRECONDITIONS_END in the definition of a narrow contract function. These macros are to be placed around the function precondition checks, immediately before and after.

double mySqrt(double x)
    // Return the square root of the specified 'x'.  The behavior is
    // undefined unless 'x >= 0'.
{
    BSLS_PRECONDITIONS_BEGIN();
    BSLS_ASSERT(0 <= x);
    BSLS_PRECONDITIONS_END();
    return sqrt(x);
}

In a fuzz-enabled build, we would invoke this function inside the fuzz loop with BSLS_FUZZTEST_EVALUATE.

Macro Definition Documentation

BSLS_PRECONDITIONS_BEGIN

#define BSLS_PRECONDITIONS_BEGIN

(

)

do {} while(false)

BSLS_PRECONDITIONS_BEGIN_IMP

#define BSLS_PRECONDITIONS_BEGIN_IMP

(

)

Value:

        do {                                   \
        bsls::PreconditionsHandler::invokeBeginHandler();                     \
    } while (false)

BSLS_PRECONDITIONS_END

#define BSLS_PRECONDITIONS_END

(

)

do {} while(false)

BSLS_PRECONDITIONS_END_IMP

#define BSLS_PRECONDITIONS_END_IMP

(

)

Value:

        do {                                     \
        bsls::PreconditionsHandler::invokeEndHandler();                       \
    } while (false)