[PATCH] PR64959: SFINAE in UDLs
Andrea Azzarone
azzaronea@gmail.com
Mon Feb 9 13:27:00 GMT 2015
Hi all,
atm enable_if cannot be used to select between overload of UDLs. E.g.
https://gcc.gnu.org/bugzilla/attachment.cgi?id=34684 will not compile.
This can be easily fixed making sure that lookup_literal_operator
returns all the possible candidates and not just the first match. I
made some more changes in parser.c to improve diagnostic in case of
failures. Four testcases added:
* udlit-sfinae.C
* udlit-sfinae.neg.C
* udlit-char-template-sfinae.C
* udlit-char-template-sfinae-neg.C
The first make check showed a failures in udlit-resolve.C. Actually
the failures was a false positive, because UDLs lookup is a normal
unqualified name lookup. I added two tests:
* udlit-namespace-ambiguous.C
* udlit-namespace-ambiguous-neg.C
At the end I also noticed a bug in string template literals. As per
N3599 the lookup should give precedence to operator""_t(const char*,
unsigned long). I updated the code in parser.C and added a test.
Please note that this is my first gcc patch :)
2015-2-9 Andrea Azzarone <azzaronea@gmail.com>
PR c++/64959
* gcc/cp/parser.c: Make sure lookup_literal_operator returns all
the possible candidates. Also improve the diagnostic messages.
* gcc/testsuite/g++.dg/cpp0x/udlit-namespace-ambiguous.C: Add test
case to make sure gcc detects ambiguous UDL declarations.
* gcc/testsuite/g++.dg/cpp0x/udlit-namespace-using-directive.C:
Add test case to make sure gcc correctly handles using directive for
UDLs.
* gcc/testsuite/g++.dg/cpp0x/udlit-resolve.C: Remove a incorrect test case.
* gcc/testsuite/g++.dg/cpp0x/udlit-sfinae.C: Add a test case to
make sure that enable_if can be used to select between overloads of
UDLs.
* gcc/testsuite/g++.dg/cpp0x/udlit-sfinae-neg.C: Add a test case
to make sure gcc correctly detects substitution failures when all the
UDSL overloads are disabled by enable_if.
* gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae-neg.C:
Like cpp0x/udlit-sfinae-neg.C but for string template literals.
* gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae.C: Like
cpp0x/udlit-sfinae.C but for string template literals.
* gcc/testsuite/g++.dg/cpp1y/udlit-char-template-vs-std-literal-operator.C:
Add a test to make sure that string template literals have a smaller
priority than standard literal operators.
--
Andrea Azzarone
-------------- next part --------------
Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c (revision 220454)
+++ gcc/cp/parser.c (working copy)
@@ -3828,7 +3828,7 @@ lookup_literal_operator (tree name, vec<
work in presence of default arguments on the literal
operator parameters. */
&& parmtypes == void_list_node)
- return fn;
+ return decl;
}
}
@@ -3955,7 +3955,7 @@ cp_parser_userdef_numeric_literal (cp_pa
decl = lookup_literal_operator (name, args);
if (decl && decl != error_mark_node)
{
- result = finish_call_expr (decl, &args, false, true, tf_none);
+ result = finish_call_expr (decl, &args, false, true, tf_warning_or_error);
if (result != error_mark_node)
{
if (TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE && overflow > 0)
@@ -3986,7 +3986,7 @@ cp_parser_userdef_numeric_literal (cp_pa
decl = lookup_literal_operator (name, args);
if (decl && decl != error_mark_node)
{
- result = finish_call_expr (decl, &args, false, true, tf_none);
+ result = finish_call_expr (decl, &args, false, true, tf_warning_or_error);
if (result != error_mark_node)
{
release_tree_vector (args);
@@ -4004,13 +4004,12 @@ cp_parser_userdef_numeric_literal (cp_pa
{
tree tmpl_args = make_char_string_pack (num_string);
decl = lookup_template_function (decl, tmpl_args);
- result = finish_call_expr (decl, &args, false, true, tf_none);
- if (result != error_mark_node)
- {
- release_tree_vector (args);
- return result;
- }
+ result = finish_call_expr (decl, &args, false, true, tf_warning_or_error);
+
+ release_tree_vector (args);
+ return result;
}
+
release_tree_vector (args);
error ("unable to find numeric literal operator %qD", name);
@@ -4035,6 +4034,24 @@ cp_parser_userdef_string_literal (tree l
tree decl, result;
vec<tree, va_gc> *args;
+ /* Build up a call to the user-defined operator */
+ /* Lookup the name we got back from the id-expression. */
+ args = make_tree_vector ();
+ vec_safe_push (args, value);
+ vec_safe_push (args, build_int_cst (size_type_node, len));
+ decl = lookup_literal_operator (name, args);
+
+ if (decl && decl != error_mark_node)
+ {
+ result = finish_call_expr (decl, &args, false, true, tf_warning_or_error);
+ if (result != error_mark_node)
+ {
+ release_tree_vector (args);
+ return result;
+ }
+ }
+ release_tree_vector (args);
+
/* Look for a template function with typename parameter CharT
and parameter pack CharT... Call the function with
template parameter characters representing the string. */
@@ -4044,31 +4061,15 @@ cp_parser_userdef_string_literal (tree l
{
tree tmpl_args = make_string_pack (value);
decl = lookup_template_function (decl, tmpl_args);
- result = finish_call_expr (decl, &args, false, true, tf_none);
+ result = finish_call_expr (decl, &args, false, true, tf_warning_or_error);
if (result != error_mark_node)
- {
- release_tree_vector (args);
- return result;
- }
+ {
+ release_tree_vector (args);
+ return result;
+ }
}
release_tree_vector (args);
- /* Build up a call to the user-defined operator */
- /* Lookup the name we got back from the id-expression. */
- args = make_tree_vector ();
- vec_safe_push (args, value);
- vec_safe_push (args, build_int_cst (size_type_node, len));
- decl = lookup_name (name);
- if (!decl || decl == error_mark_node)
- {
- error ("unable to find string literal operator %qD", name);
- release_tree_vector (args);
- return error_mark_node;
- }
- result = finish_call_expr (decl, &args, false, true, tf_none);
- release_tree_vector (args);
- if (result != error_mark_node)
- return result;
error ("unable to find string literal operator %qD with %qT, %qT arguments",
name, TREE_TYPE (value), size_type_node);
Index: gcc/testsuite/g++.dg/cpp0x/udlit-namespace-ambiguous.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-namespace-ambiguous.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-namespace-ambiguous.C (working copy)
@@ -0,0 +1,18 @@
+// { dg-do compile { target c++11 } }
+
+int operator""_t(long long unsigned); // { dg-message "note: candidate"}
+
+namespace foo {
+ int operator""_t(long long unsigned); // { dg-message "note: candidate"}
+}
+
+using namespace foo;
+
+int main()
+{
+ 10_t;
+}
+
+// { dg-error "call of overloaded|is ambiguous" 13}
+// { dg-error "unable to find numeric literal operator" 13}
+// { dg-message "note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes" }
Index: gcc/testsuite/g++.dg/cpp0x/udlit-namespace-using-directive.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-namespace-using-directive.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-namespace-using-directive.C (working copy)
@@ -0,0 +1,16 @@
+// { dg-do compile { target c++11 } }
+
+int operator""_t(long long unsigned) {
+ return 0;
+}
+
+namespace foo {
+ int operator""_t(long long unsigned) {
+ return 0;
+ }
+}
+
+int main() {
+ using foo::operator""_t;
+ 10_t;
+}
Index: gcc/testsuite/g++.dg/cpp0x/udlit-resolve.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-resolve.C (revision 220454)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-resolve.C (working copy)
@@ -17,15 +17,10 @@ int operator"" _foo(const char32_t*, std
template<char...> int operator"" _foo2() { return 20; }
int operator"" _foo2(unsigned long long int) { return 21; }
-namespace bar {
-int operator"" _foo(unsigned long long int) { return 101; }
-}
-using namespace bar;
-
int
main()
{
- assert(123_foo == 101);
+ assert(123_foo == 1);
assert(0.123_foo == 2);
assert('c'_foo == 3);
assert(L'c'_foo == 4);
Index: gcc/testsuite/g++.dg/cpp0x/udlit-sfinae-neg.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-sfinae-neg.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-sfinae-neg.C (working copy)
@@ -0,0 +1,21 @@
+// { dg-do compile { target c++11 } }
+// { dg-prune-output "note:" }
+
+template<bool, typename _Tp = void> struct enable_if { };
+template<typename _Tp> struct enable_if<true, _Tp> { typedef _Tp type; };
+
+template <char... c>
+constexpr typename enable_if<sizeof...(c) == 2, int>::type operator""_t() // { dg-error "no type named|in" }
+{
+ return 2;
+}
+
+template <char... c>
+constexpr typename enable_if<sizeof...(c) == 1, int>::type operator""_t() // { dg-error "no type named|in" }
+{
+ return 1;
+}
+
+int a = 45_t;
+int b = 4_t;
+int c = 100000_t; // { dg-error "no matching function for call to" }
Index: gcc/testsuite/g++.dg/cpp0x/udlit-sfinae.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-sfinae.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-sfinae.C (working copy)
@@ -0,0 +1,38 @@
+// { dg-do run { target c++11 } }
+
+#include <cassert>
+
+template<bool, typename _Tp = void> struct enable_if { };
+template<typename _Tp> struct enable_if<true, _Tp> { typedef _Tp type; };
+
+
+template <char... c>
+constexpr typename enable_if<sizeof...(c) == 2, int>::type operator""_t()
+{
+ return 2;
+}
+
+template <char... c>
+constexpr typename enable_if<sizeof...(c) == 1, int>::type operator""_t()
+{
+ return 1;
+}
+
+template <char... c>
+constexpr typename enable_if<sizeof...(c) >= 3, int>::type operator""_t()
+{
+ return 100;
+}
+
+int operator""_t(long double)
+{
+ return 200;
+}
+
+int main()
+{
+ assert(45_t == 2);
+ assert(4_t == 1);
+ assert(100000_t == 100);
+ assert(200.0_t == 200);
+}
Index: gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae-neg.C
===================================================================
--- gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae-neg.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae-neg.C (working copy)
@@ -0,0 +1,21 @@
+// { dg-do compile { target c++14 } }
+// { dg-prune-output "note:" }
+
+template<bool, typename _Tp = void>struct enable_if {};
+template<typename _Tp> struct enable_if<true, _Tp> { typedef _Tp type; };
+
+
+template<typename CharT, CharT... String>
+typename enable_if<sizeof...(String) == 1, int>::type operator"" _script() { // { dg-error "no type named|in" }
+ return 1;
+}
+
+template<typename CharT, CharT... String>
+typename enable_if<sizeof...(String) == 2, int>::type operator"" _script() { // { dg-error "no type named|in" }
+ return 2;
+}
+
+int a = "1"_script;
+int b = "22"_script;
+int c = "333"_script; // { dg-error "no matching function for call to"}
+ // { dg-error "unable to find string literal operator" 20}
Index: gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae.C
===================================================================
--- gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp1y/udlit-char-template-sfinae.C (working copy)
@@ -0,0 +1,29 @@
+// { dg-do run { target c++14 } }
+
+#include <cassert>
+
+template<bool, typename _Tp = void>struct enable_if {};
+template<typename _Tp> struct enable_if<true, _Tp> { typedef _Tp type; };
+
+
+template<typename CharT, CharT... String>
+typename enable_if<sizeof...(String) == 6, int>::type operator"" _script() {
+ return 5;
+}
+
+template<typename CharT, CharT... String>
+typename enable_if<sizeof...(String) == 3, int>::type operator"" _script() {
+ return 3;
+}
+
+template<typename CharT, CharT... String>
+typename enable_if<sizeof...(String) != 3 && sizeof...(String) != 6, int>::type operator"" _script() {
+ return 1;
+}
+
+int main()
+{
+ assert("hello!"_script == 5);
+ assert(u8"hi!"_script == 3);
+ assert("hey!"_script == 1);
+}
Index: gcc/testsuite/g++.dg/cpp1y/udlit-char-template-vs-std-literal-operator.C
===================================================================
--- gcc/testsuite/g++.dg/cpp1y/udlit-char-template-vs-std-literal-operator.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp1y/udlit-char-template-vs-std-literal-operator.C (working copy)
@@ -0,0 +1,17 @@
+// { dg-do run { target c++14 } }
+
+#include <cassert>
+
+template<typename CharT, CharT... String>
+int operator"" _script() {
+ return 1;
+}
+
+int operator"" _script(const char*, unsigned long) {
+ return 2;
+}
+
+int main ()
+{
+ assert("123"_script == 2);
+}
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