On Mon, Apr 23, 2012 at 7:53 AM, Gabriel Dos Reis
<g...@integrable-solutions.net> wrote:
> On Mon, Apr 23, 2012 at 7:30 AM, Ollie Wild <a...@google.com> wrote:
>>
>> Do you still want me to shorten in?
>
> yes.
Done. Updated patch attached.
Ollie
commit 3f53671fb7fc7811277f047e7914f78e127031a6
Author: Ollie Wild <a...@google.com>
Date: Sun Apr 22 21:37:08 2012 -0500
Add new option, -Wreserved-user-defined-literal.
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.
2012-04-22 Ollie Wild <a...@google.com>
* 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.
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 4eacd19..bf5b034 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_LITERAL_SUFFIX, OPT_Wliteral_suffix},
{CPP_W_NONE, 0}
};
diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index 17e1958..2510747 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -476,6 +476,10 @@ c_common_handle_option (size_t scode, const char *arg, int
value,
cpp_opts->warn_invalid_pch = value;
break;
+ case OPT_Wliteral_suffix:
+ cpp_opts->warn_literal_suffix = value;
+ break;
+
case OPT_Wlong_long:
cpp_opts->cpp_warn_long_long = value;
break;
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index d8c944d..db8ca81 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -449,6 +449,10 @@ Wjump-misses-init
C ObjC Var(warn_jump_misses_init) Init(-1) Warning
Warn when a jump misses a variable initialization
+Wliteral-suffix
+C++ ObjC++ Warning
+Warn when a string or character literal is followed by a ud-suffix which does
not begin with an underscore.
+
Wlogical-op
C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
Warn when a logical operator is suspiciously always evaluating to true or false
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 8ca2f4e..3c9588a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -198,8 +198,8 @@ in the following sections.
-fno-default-inline -fvisibility-inlines-hidden @gol
-fvisibility-ms-compat @gol
-Wabi -Wconversion-null -Wctor-dtor-privacy @gol
--Wdelete-non-virtual-dtor -Wnarrowing -Wnoexcept @gol
--Wnon-virtual-dtor -Wreorder @gol
+-Wdelete-non-virtual-dtor -Wliteral-suffix -Wnarrowing @gol
+-Wnoexcept -Wnon-virtual-dtor -Wreorder @gol
-Weffc++ -Wstrict-null-sentinel @gol
-Wno-non-template-friend -Wold-style-cast @gol
-Woverloaded-virtual -Wno-pmf-conversions @gol
@@ -2425,6 +2425,30 @@ an instance of a derived class through a pointer to a
base class if the
base class does not have a virtual destructor. This warning is enabled
by @option{-Wall}.
+@item -Wliteral-suffix @r{(C++ and Objective-C++ only)}
+@opindex Wliteral-suffix
+@opindex Wno-literal-suffix
+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.
+
@item -Wnarrowing @r{(C++ and Objective-C++ only)}
@opindex Wnarrowing
@opindex Wno-narrowing
diff --git a/gcc/testsuite/g++.dg/cpp0x/Wliteral-suffix.C
b/gcc/testsuite/g++.dg/cpp0x/Wliteral-suffix.C
new file mode 100644
index 0000000..39a8353
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/Wliteral-suffix.C
@@ -0,0 +1,29 @@
+// { dg-do run }
+// { dg-options "-std=c++0x" }
+
+// Make sure -Wliteral-suffix 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..9dbc477 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_literal_suffix;
+
/* 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_LITERAL_SUFFIX
};
/* Output a diagnostic of some kind. */
diff --git a/libcpp/init.c b/libcpp/init.c
index 5fa82ca..3262184 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_literal_suffix) = 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..edab996 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_literal_suffix))
+ cpp_warning_with_line (pfile, CPP_W_LITERAL_SUFFIX,
+ 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_literal_suffix))
+ cpp_warning_with_line (pfile, CPP_W_LITERAL_SUFFIX,
+ 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;
