[Bug preprocessor/21521] New: -finput-charset -save-temps converts characters twice

[jsm28 at gcc dot gnu dot org]

Compile the following iso-8859-1 file with -finput-charset=iso-8859-1.  In the
output the string has been converted to UTF-8 as documented.  Compile it with
-finput-charset=iso-8859-1 -save-temps.  In the output the string has been
converted to UTF-8, then that UTF-8 treated as ISO-8859-1 and converted to UTF-8
again, which is incorrect.  If preprocessed output is always in UTF-8 then
preprocessed input must always be treated as in UTF-8 regardless of -finput-charset.

const char s[] = "§";

Compilation time test not requiring execution or scanning assembler:

int a = L'§';

compiled with -finput-charset=iso-8859-1 -save-temps gives a bogus "warning:
character constant too long for its type".

-- 
           Summary: -finput-charset -save-temps converts characters twice
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jsm28 at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21521