This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.
Authors: Derek M. Jones, WG14
Date: 1992-12-10
Reference document: X3J11/90-056
Submitted against: C90
Status: Fixed
Fixed in: C90 TC1
Converted from: dr.htm, dr_017.html
New-line in preprocessor directives
Subclause 5.1.1.2, page 5, line 37 says: “Preprocessing directives are executed and macro invocations are expanded.”
Subclause 6.8, page 86, lines 2-5 say: “A preprocessing directive ... and is ended by the next new-line character.”
Subclause 6.8.3, page 89, lines 38-39 say: “Within the sequence of preprocessing tokens ... new-line is considered a normal white-space character.”
These three statements are not sufficient to categorize the following:
#define f(a,b) a+b
#if f(1,
2)
...
It should be defined whether the preprocessing directive rule or macro expansion wins, i.e. is this code fragment legal or illegal?
In translation phase 4 “preprocessing directives are executed and macro invocations expanded.”
Now do macro invocations get done first, followed by preprocessor directives? Does the macro expander need to know that what it is expanding forms a preprocessing directive?
Subclause 6.8, page 86, lines 2-5 suggest that the preprocessor directive is examined to look for the new-line character. But how is it examined? Obviously phases 1-3 happen during this examination. So why shouldn't part of phase 4?
Comment from WG14 on 1997-09-23:
Add to subclause 6.8, page 86, line 5, (Description):
A new-line character ends the preprocessing directive even if it occurs within what would otherwise be an invocation of a function-like macro.