This option, which is enabled by default, causes the preprocessor to warn
when a string or character literal is followed by a ud-suffix which does
not begin with an underscore. According to [lex.ext]p10, this is
ill-formed.
Also modifies the preprocessor to treat such ill-formed suffixes as separate
preprocessing tokens. This is consistent with the Clang front end (see
http://llvm.org/viewvc/llvm-project?view=rev&revision=152287), and enables
backwards compatibility with code that uses formatting macros from
<inttypes.h>, as in the following code block:
int main() {
int64_t i64 = 123;
printf("My int64: %"PRId64"\n", i64);
}
Google ref b/6377711.
2012-04-27 Ollie Wild <aaw@google.com>
PR c++/52538
* gcc/c-family/c-common.c: Add CPP_W_LITERAL_SUFFIX mapping.
* gcc/c-family/c-opts.c (c_common_handle_option): Handle
OPT_Wliteral_suffix.
* gcc/c-family/c.opt: Add Wliteral-suffix.
* gcc/doc/invoke.texi (Wliteral-suffix): Document new option.
* gcc/testsuite/g++.dg/cpp0x/Wliteral-suffix.c: New test.
* libcpp/include/cpplib.h (struct cpp_options): Add new field,
warn_literal_suffix.
(CPP_W_LITERAL_SUFFIX): New enum.
* libcpp/init.c (cpp_create_reader): Default initialization of
warn_literal_suffix.
* libcpp/lex.c (lex_raw_string): Treat user-defined literals which
don't begin with '_' as separate tokens and produce a warning.
(lex_string): Ditto.
From-SVN: r186909
7f5f5f98c5