09-09-2005, 02:21 PM
Code:
#define M1 ;This macro breaks rule 19.4. Macro expanding to Null statement is not allowed/
Code:
#define M2
#define M3 /* comment */This macro expands to no body, and is therefore not prohibited by 19.4.
A comment in a macro definition is removed by the pre-processor. Rule 14.3 applied before
Pre-processing. Treatment of M2 and M3 is identical.
Code:
M1Since definition of M1 macro was invalid, its use is already a violation.
Code:
M2;
M3;After pre-processing, these are both Null statements. Before pre-processing, there are characters before the Null statement. This is not allowed by 14.3.