OK, thanks.
On Tue, Dec 5, 2017 at 7:33 AM, Jakub Jelinek <ja...@redhat.com> wrote: > On Fri, Dec 01, 2017 at 03:16:23PM -0500, Jason Merrill wrote: >> commit e39b7d506d236ce7ef9f64d1bcf0b384bb2d8038 >> Author: Jason Merrill <ja...@redhat.com> >> Date: Fri Dec 1 07:45:03 2017 -0500 >> >> PR c++/79228 - extensions hide C++14 complex literal operators >> >> libcpp/ >> * expr.c (interpret_float_suffix): Ignore 'i' in C++14 and up. >> (interpret_int_suffix): Likewise. >> gcc/cp/ >> * parser.c (cp_parser_userdef_numeric_literal): Be helpful about >> 'i' in C++14 and up. >> >> + /* In C++14 and up these suffixes are in the standard library, so >> treat >> + them as user-defined literals. */ >> + if (CPP_OPTION (pfile, cplusplus) >> + && CPP_OPTION (pfile, lang) > CLK_CXX11 >> + && (!memcmp (orig_s, "i", orig_len) >> + || !memcmp (orig_s, "if", orig_len) >> + || !memcmp (orig_s, "il", orig_len))) > > This doesn't seem right, it will invoke UB if orig_len > 2 by potentially > accessing bytes beyond 'i' and '\0' in "i" (and for orig_len > 3 also after > "if" or "il"). > If you only want to return 0 if orig_len bytes starting at orig_s are 'i' > or 'i' 'f' or 'i' 'l', then I'd write instead as in the patch below. > Or if memcmp is more readable, at least check orig_len first. > >> + /* In C++14 and up these suffixes are in the standard library, so >> treat >> + them as user-defined literals. */ >> + if (CPP_OPTION (pfile, cplusplus) >> + && CPP_OPTION (pfile, lang) > CLK_CXX11 >> + && (!memcmp (s, "i", orig_len) >> + || !memcmp (s, "if", orig_len) >> + || !memcmp (s, "il", orig_len))) > > Similarly. Additionally, "if" can't happen here, because we don't allow 'f' > among suffixes. > > So, ok for trunk if it passes testing, or some other form thereof? > > 2017-12-05 Jakub Jelinek <ja...@redhat.com> > > PR c++/79228 > * expr.c (interpret_float_suffix): Avoid memcmp. > (interpret_int_suffix): Likewise. Don't check for if. > > --- libcpp/expr.c.jj 2017-12-01 22:13:24.000000000 +0100 > +++ libcpp/expr.c 2017-12-05 13:26:57.019683785 +0100 > @@ -280,9 +280,10 @@ interpret_float_suffix (cpp_reader *pfil > them as user-defined literals. */ > if (CPP_OPTION (pfile, cplusplus) > && CPP_OPTION (pfile, lang) > CLK_CXX11 > - && (!memcmp (orig_s, "i", orig_len) > - || !memcmp (orig_s, "if", orig_len) > - || !memcmp (orig_s, "il", orig_len))) > + && orig_s[0] == 'i' > + && (orig_len == 1 > + || (orig_len == 2 > + && (orig_s[1] == 'f' || orig_s[1] == 'l')))) > return 0; > } > > @@ -345,9 +346,8 @@ interpret_int_suffix (cpp_reader *pfile, > them as user-defined literals. */ > if (CPP_OPTION (pfile, cplusplus) > && CPP_OPTION (pfile, lang) > CLK_CXX11 > - && (!memcmp (s, "i", orig_len) > - || !memcmp (s, "if", orig_len) > - || !memcmp (s, "il", orig_len))) > + && s[0] == 'i' > + && (orig_len == 1 || (orig_len == 2 && s[1] == 'l'))) > return 0; > } > > > > Jakub
