Paul Eggert wrote: > > $ gcc -Wall -S foo.c > > foo.c:1: warning: integer constant is too large for ‘long’ type > > I don't see how that would produce incorrect code for byteswap.h.
Indeed, gcc 4.4.7 warns but produces a long long value (no truncation). > The longer story is C89 lacked 'long long'. Also, in C89 on a 32-bit int > platform the decimal integer literal 2147483648 had type 'unsigned int' > because 2147483648 fits in 'unsigned int' but not plain 'int'. Although > this misfeature was fixed in C99 it was present in many compilers for > some time after that. (It still seems to be present in MS Visual Studio! > See > <https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-2-c4146?view=msvc-170>.) > > To help write portable code, GCC formerly warned about integer constants > that might not be portable to C89, but it then went ahead and produced > correct code. Thanks for explaining. I remember that at least in the preprocessor, truncation did occur. I don't remember when in the object code the compilers (other than MSVC) stopped doing the truncation. > The need for these warnings went away long ago (except perhaps for > Microsoft...) but they can be annoying so I installed the attached patch > to pacify older GCCs. Thanks! Bruno
