On Sun, Apr 22, 2012 at 10:59 PM, Ollie Wild <a...@google.com> wrote: > Add new option, -Wreserved-user-defined-literal.
Just shorten it to -Wliteral-suffix. > > 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. the non-CPP part is OK with the above change. You would need Tom's approval for the CPP part. > > 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); > } > > Tested via bootstrap + test. > > Okay for trunk? > > Thanks, > Ollie > > > 2012-04-22 Ollie Wild <a...@google.com> > > * gcc/c-family/c-common.c: > * gcc/c-family/c-opts.c (c_common_handle_option): > * gcc/c-family/c.opt: > * gcc/doc/invoke.texi (struct A): > * gcc/testsuite/g++.dg/cpp0x/Wreserved-user-defined-literal.C (test): > (main): > * libcpp/include/cpplib.h (struct cpp_options): > * libcpp/init.c (cpp_create_reader): > * libcpp/lex.c (lex_raw_string): > (lex_string): > > diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c > index 4eacd19..f79020c 100644 > --- a/gcc/c-family/c-common.c > +++ b/gcc/c-family/c-common.c > @@ -8820,6 +8820,7 @@ static const struct reason_option_codes_t > option_codes[] = { > {CPP_W_NORMALIZE, OPT_Wnormalized_}, > {CPP_W_INVALID_PCH, OPT_Winvalid_pch}, > {CPP_W_WARNING_DIRECTIVE, OPT_Wcpp}, > + {CPP_W_RESERVED_USER_LITERALS, OPT_Wreserved_user_defined_literal}, > {CPP_W_NONE, 0} > }; > > diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c > index 17e1958..a812762 100644 > --- a/gcc/c-family/c-opts.c > +++ b/gcc/c-family/c-opts.c > @@ -510,6 +510,10 @@ c_common_handle_option (size_t scode, const char *arg, > int value, > break; > } > > + case OPT_Wreserved_user_defined_literal: > + cpp_opts->warn_reserved_user_literals = value; > + break; > + > case OPT_Wreturn_type: > warn_return_type = value; > break; > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > index d8c944d..c8a0c84 100644 > --- a/gcc/c-family/c.opt > +++ b/gcc/c-family/c.opt > @@ -593,6 +593,10 @@ Wreorder > C++ ObjC++ Var(warn_reorder) Warning > Warn when the compiler reorders code > > +Wreserved-user-defined-literal > +C++ ObjC++ Warning > +Warn when a string or character literal is followed by a ud-suffix which > does not begin with an underscore. > + > Wreturn-type > C ObjC C++ ObjC++ Var(warn_return_type) Warning > Warn whenever a function's return type defaults to \"int\" (C), or about > inconsistent return types (C++) > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index 8ca2f4e..ddf0fc6 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -199,7 +199,7 @@ in the following sections. > -fvisibility-ms-compat @gol > -Wabi -Wconversion-null -Wctor-dtor-privacy @gol > -Wdelete-non-virtual-dtor -Wnarrowing -Wnoexcept @gol > --Wnon-virtual-dtor -Wreorder @gol > +-Wnon-virtual-dtor -Wreorder -Wreserved-user-defined-literal @gol > -Weffc++ -Wstrict-null-sentinel @gol > -Wno-non-template-friend -Wold-style-cast @gol > -Woverloaded-virtual -Wno-pmf-conversions @gol > @@ -2478,6 +2478,30 @@ struct A @{ > The compiler rearranges the member initializers for @samp{i} > and @samp{j} to match the declaration order of the members, emitting > a warning to that effect. This warning is enabled by @option{-Wall}. > + > +@item -Wreserved-user-defined-literal @r{(C++ and Objective-C++ only)} > +@opindex Wreserved-user-defined-literal > +@opindex Wno-reserved-user-defined-literal > +Warn when a string or character literal is followed by a ud-suffix which does > +not begin with an underscore. As a conforming extension, GCC treats such > +suffixes as separate preprocessing tokens in order to maintain backwards > +compatibility with code that uses formatting macros from @code{<inttypes.h>}. > +For example: > + > +@smallexample > +#define __STDC_FORMAT_MACROS > +#include <inttypes.h> > +#include <stdio.h> > + > +int main() @{ > + int64_t i64 = 123; > + printf("My int64: %"PRId64"\n", i64); > +@} > +@end smallexample > + > +In this case, @code{PRId64} is treated as a separate preprocessing token. > + > +This warning is enabled by default. > @end table > > The following @option{-W@dots{}} options are not affected by @option{-Wall}. > diff --git a/gcc/testsuite/g++.dg/cpp0x/Wreserved-user-defined-literal.C > b/gcc/testsuite/g++.dg/cpp0x/Wreserved-user-defined-literal.C > new file mode 100644 > index 0000000..66de5c0 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/Wreserved-user-defined-literal.C > @@ -0,0 +1,29 @@ > +// { dg-do run } > +// { dg-options "-std=c++0x" } > + > +// Make sure -Wreserved-user-defined-literal is enabled by default and > +// triggers as expected. > + > +#define BAR "bar" > +#define PLUS_ONE + 1 > + > +#include <cstdint> > +#include <cassert> > + > + > +void > +test() > +{ > + char c = '3'PLUS_ONE; // { dg-warning "invalid suffix on literal" > } > + char s[] = "foo"BAR; // { dg-warning "invalid suffix on literal" } > + > + assert(c == '4'); > + assert(s[3] != '\0'); > + assert(s[3] == 'b'); > +} > + > +int > +main() > +{ > + test(); > +} > diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h > index bf59d01..84cacb0 100644 > --- a/libcpp/include/cpplib.h > +++ b/libcpp/include/cpplib.h > @@ -427,6 +427,10 @@ struct cpp_options > /* Nonzero for C++ 2011 Standard user-defnied literals. */ > unsigned char user_literals; > > + /* Nonzero means warn when a string or character literal is followed by a > + ud-suffix which does not beging with an underscore. */ > + unsigned char warn_reserved_user_literals; > + > /* Holds the name of the target (execution) character set. */ > const char *narrow_charset; > > @@ -906,7 +910,8 @@ enum { > CPP_W_CXX_OPERATOR_NAMES, > CPP_W_NORMALIZE, > CPP_W_INVALID_PCH, > - CPP_W_WARNING_DIRECTIVE > + CPP_W_WARNING_DIRECTIVE, > + CPP_W_RESERVED_USER_LITERALS > }; > > /* Output a diagnostic of some kind. */ > diff --git a/libcpp/init.c b/libcpp/init.c > index 5fa82ca..2688699 100644 > --- a/libcpp/init.c > +++ b/libcpp/init.c > @@ -175,6 +175,7 @@ cpp_create_reader (enum c_lang lang, hash_table *table, > CPP_OPTION (pfile, warn_variadic_macros) = 1; > CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1; > CPP_OPTION (pfile, warn_normalize) = normalized_C; > + CPP_OPTION (pfile, warn_reserved_user_literals) = 1; > > /* Default CPP arithmetic to something sensible for the host for the > benefit of dumb users like fix-header. */ > diff --git a/libcpp/lex.c b/libcpp/lex.c > index 9d23002..3589a81 100644 > --- a/libcpp/lex.c > +++ b/libcpp/lex.c > @@ -1553,14 +1553,30 @@ lex_raw_string (cpp_reader *pfile, cpp_token *token, > const uchar *base, > > if (CPP_OPTION (pfile, user_literals)) > { > + /* According to C++11 [lex.ext]p10, a ud-suffix not starting with an > + underscore is ill-formed. Since this breaks programs using macros > + from inttypes.h, we generate a warning and treat the ud-suffix as a > + separate preprocessing token. This approach is under discussion by > + the standards committee, and has been adopted as a conforming > + extension by other front ends such as clang. */ > + if (ISALPHA(*cur)) > + { > + // Raise a warning, but do not consume subsequent tokens. > + if (CPP_OPTION (pfile, warn_reserved_user_literals)) > + cpp_warning_with_line (pfile, CPP_W_RESERVED_USER_LITERALS, > + token->src_loc, 0, > + "invalid suffix on literal; C++11 requires > " > + "a space between literal and identifier"); > + } > /* Grab user defined literal suffix. */ > - if (ISIDST (*cur)) > + else if (*cur == '_') > { > type = cpp_userdef_string_add_type (type); > ++cur; > + > + while (ISIDNUM (*cur)) > + ++cur; > } > - while (ISIDNUM (*cur)) > - ++cur; > } > > pfile->buffer->cur = cur; > @@ -1668,15 +1684,31 @@ lex_string (cpp_reader *pfile, cpp_token *token, > const uchar *base) > > if (CPP_OPTION (pfile, user_literals)) > { > + /* According to C++11 [lex.ext]p10, a ud-suffix not starting with an > + underscore is ill-formed. Since this breaks programs using macros > + from inttypes.h, we generate a warning and treat the ud-suffix as a > + separate preprocessing token. This approach is under discussion by > + the standards committee, and has been adopted as a conforming > + extension by other front ends such as clang. */ > + if (ISALPHA(*cur)) > + { > + // Raise a warning, but do not consume subsequent tokens. > + if (CPP_OPTION (pfile, warn_reserved_user_literals)) > + cpp_warning_with_line (pfile, CPP_W_RESERVED_USER_LITERALS, > + token->src_loc, 0, > + "invalid suffix on literal; C++11 requires > " > + "a space between literal and identifier"); > + } > /* Grab user defined literal suffix. */ > - if (ISIDST (*cur)) > + else if (*cur == '_') > { > type = cpp_userdef_char_add_type (type); > type = cpp_userdef_string_add_type (type); > ++cur; > + > + while (ISIDNUM (*cur)) > + ++cur; > } > - while (ISIDNUM (*cur)) > - ++cur; > } > > pfile->buffer->cur = cur; > > -- > This patch is available for review at http://codereview.appspot.com/6109043
