diff --git a/gcc/README.TRAD b/gcc/README.TRAD new file mode 100644 index 00000000000..07ccd16437b --- /dev/null +++ b/gcc/README.TRAD @@ -0,0 +1,55 @@ +This is a partial list of how `gcc -traditional' disagrees with +traditional C compilers (perhaps only some of them). Most of these +differences are not bugs. + +--------------------------------------------------------------------------- +K&R-1 (2.4.3) says: + + "If the character following a backslash is not one of those + specified {in the table above}, the backslash is ignored." + +Up until recently, `gcc -traditional' complained about \x \a and \v +appearing in a character or string literal. I believe however that +this non-feature has been eliminated (recently). + +--------------------------------------------------------------------------- +When in -traditional mode, gcc allows the following erroneous pair of +declarations to appear together in a given scope: + + typedef int foo; + typedef foo foo; + +--------------------------------------------------------------------------- +K&R-1 (8.5) says: + + "No field may be wider than a word." + +Gcc however allows: + + struct S { int i:33; }; + +--------------------------------------------------------------------------- +In K&R-1 there is no restriction against comments crossing include file +boundaries. Gcc however doesn't allow this, even when in -traditional mode. + +--------------------------------------------------------------------------- +Regarding the length of identifiers, K&R-1 (2.2) says: + + "No more than the first eight characters are significant, + although more may be used." + +Gcc treats all characters of identifiers as significant, even when in +-traditional mode. + +--------------------------------------------------------------------------- +K&R-1 (2.2) says: + + "An identifier is a sequence of letters and digits; the first + character must be a letter. The underscore _ counts as a letter." + +Gcc also allows dollar signs in identifiers. (This may also be an issue +for the -pedantic option.) + +--------------------------------------------------------------------------- + +