This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.
Authors: Fred J. Tydeman, J11
Date: 2006-07-18
Reference document: N1183
Submitted against: C99
Status: Fixed
Fixed in: C11
Converted from: summary-c99.htm, dr_330.htm
C99 7.12.1 Treatment of error conditions paragraph 1 has: Each function shall execute as if it were a single operation without generating any externally visible exceptional conditions.
As written, I believe that means that errno cannot be altered by any math
function, nor can any of the floating-point exceptions mentioned later in 7.12.1
("invalid", "divide-by-zero", "overflow", "underflow") be raised by any math
function.
That was not our intent.
Seems to me that there are two problems with that text in 7.12.1:
Comment from WG14 on 2007-10-30:
In the Rationale, please add to section 6.5 Expressions, as a new paragraph, words along the lines of:
The "inexact" floating-point exception is NOT an exceptional condition because "inexact" arises from computing a mathematically defined value in the range of representable values, therefore, from the definition, "inexact" is not exceptional. This matters for spurious exceptional conditions in the math library (7.12.1).
Change 7.12.1 paragraph 1 last sentence to:
Each function shall execute as if it were a single operation without generating any of the exceptions "invalid", "divide-by-zero", or "overflow" except to reflect the result of the function.