freebsd-src/contrib/gcc/README.TRAD

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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.
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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).
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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;
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K&R-1 (8.5) says:
"No field may be wider than a word."
Gcc however allows:
struct S { int i:33; };
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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.
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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.
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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.)
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