Re: [PATCH][C++11][ PR55582] Let string literals starting with lower-case 's' be a user-defined literal instead of string + macro.
I just noticed this patch. Since it was submitted well before the end of stage 3 and looks quite safe, it's OK to go in for 4.8. Please remember to CC/ping me for C++ patches. Thanks, Jason
Re: [PATCH][C++11][ PR55582] Let string literals starting with lower-case 's' be a user-defined literal instead of string + macro.
On 02/13/2013 01:40 PM, Jason Merrill wrote:
I just noticed this patch. Since it was submitted well before the end
of stage 3 and looks quite safe, it's OK to go in for 4.8. Please
remember to CC/ping me for C++ patches.
Thanks,
Jason
Applied the following after build and test on x86_64-unknown-linux.
Ed
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C
===
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
@@ -0,0 +1,13 @@
+// { dg-options -std=c++11 }
+// { dg-require-effective-target stdint_types }
+// PR c++/55582
+
+#include udlit-string-literal.h
+
+using namespace my_string_literals;
+
+decltype(Hello, World!s) s;
+decltype(u8Hello, World!s) s8;
+decltype(LHello, World!s) ws;
+decltype(uHello, World!s) s16;
+decltype(UHello, World!s) s32;
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h
===
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
@@ -0,0 +1,22 @@
+#pragma GCC system_header
+
+#include string
+
+inline namespace my_string_literals
+{
+ std::string
+ operator s(const char* str, std::size_t len)
+ { return std::string{str, len}; }
+
+ std::wstring
+ operator s(const wchar_t* str, std::size_t len)
+ { return std::wstring{str, len}; }
+
+ std::u16string
+ operator s(const char16_t* str, std::size_t len)
+ { return std::u16string{str, len}; }
+
+ std::u32string
+ operator s(const char32_t* str, std::size_t len)
+ { return std::u32string{str, len}; }
+}
Index: libcpp/lex.c
===
--- libcpp/lex.c(revision 196036)
+++ libcpp/lex.c(working copy)
@@ -1561,8 +1561,10 @@
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))
+extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1572,7 +1574,7 @@
a space between literal and identifier);
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_string_add_type (type);
++cur;
@@ -1692,8 +1694,10 @@
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))
+extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1703,7 +1707,7 @@
a space between literal and identifier);
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_char_add_type (type);
type = cpp_userdef_string_add_type (type);
gcc/libcpp/
2013-02-13 Ed Smith-Rowland 3dw...@verizon.net
PR c++/55582
* libcpp/lex.c (lex_raw_string): Allow string literal with suffix
beginning with 's' to be parsed as a C++11 user-defined literal.
gcc/testsuite/
2013-02-13 Ed Smith-Rowland 3dw...@verizon.net
PR c++/55582
* g++.dg/cpp0x/udlit-string-literal.h: New.
* g++.dg/cpp0x/udlit-string-literal.C: New.
[PATCH][C++11][ PR55582] Let string literals starting with lower-case 's' be a user-defined literal instead of string + macro.
There is a proposal to add several user-defined literals to the standard
library that looks like it will probably go through:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3468.pdf
The proposed string literals
std::string hw = Hello, world!s;
will not parse as a literal in gcc.
This patch fixes this by modifying the lexing of stringXYZ
user-defined literals as *two* tokens if the suffix starts with a letter
*unless the letter is a lower-case 's'*. i.e. don't parse as a
user-defined literal but as a sequence of string and macro *unless
starts with lower case 's'*.
The original code parsed all string literals with suffix beginning with
any letter as a sequence of string and macro (two tokens, not one).
Thanks,
Index: libcpp/lex.c
===
--- libcpp/lex.c(revision 194178)
+++ libcpp/lex.c(working copy)
@@ -1562,8 +1562,10 @@
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))
+extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1573,7 +1575,7 @@
a space between literal and identifier);
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_string_add_type (type);
++cur;
@@ -1693,8 +1695,10 @@
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))
+extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1704,7 +1708,7 @@
a space between literal and identifier);
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_char_add_type (type);
type = cpp_userdef_string_add_type (type);
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C
===
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
@@ -0,0 +1,12 @@
+// { dg-options -std=c++11 }
+// PR c++/55582
+
+#include udlit-string-literal.h
+
+using namespace my_string_literals;
+
+decltype(Hello, World!s) s;
+decltype(u8Hello, World!s) s8;
+decltype(LHello, World!s) ws;
+decltype(uHello, World!s) s16;
+decltype(UHello, World!s) s32;
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h
===
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
@@ -0,0 +1,22 @@
+#pragma GCC system_header
+
+#include string
+
+inline namespace my_string_literals
+{
+ std::string
+ operator s(const char* str, std::size_t len)
+ { return std::string{str, len}; }
+
+ std::wstring
+ operator s(const wchar_t* str, std::size_t len)
+ { return std::wstring{str, len}; }
+
+ std::u16string
+ operator s(const char16_t* str, std::size_t len)
+ { return std::u16string{str, len}; }
+
+ std::u32string
+ operator s(const char32_t* str, std::size_t len)
+ { return std::u32string{str, len}; }
+}
gcc/libcpp/
2012-12-05 Ed Smith-Rowland 3dw...@verizon.net
PR c++/55582
* lex.c (lex_raw_string): Allow string literal with suffix starting with
lower-case 's' as a user-defined literal.
(lex_string): Ditto.
gcc/testsuite/
2012-12-05 Ed Smith-Rowland 3dw...@verizon.net
PR c++/55582
* g++.dg/cpp0x/udlit-string-literal.h: New.
* g++.dg/cpp0x/udlit-string-literal.C: New.
