* [C++11] DR1479 - Literal operators and default arguments
@ 2014-12-24 1:23 Ed Smith-Rowland
0 siblings, 0 replies; 3+ messages in thread
From: Ed Smith-Rowland @ 2014-12-24 1:23 UTC (permalink / raw)
To: gcc-patches, Jason Merrill, NightStrike
I tried this patch a year ago and, as pointed out by NightStrike, got
lost in the shuffle.
The idea is that default arguments in literal operators would lead to
ambiguities and might not act like the uthor intends.
The earlier patch errors out. This time I just warn. I'm not sure what
we want here actually so some feedback would be nice.
I could alternatively error and add a note about default argument.
Builds and tests clean on x86_64-linux.
OK?
Ed
^ permalink raw reply [flat|nested] 3+ messages in thread
* [C++11] DR1479 - Literal operators and default arguments
@ 2014-12-24 2:17 Ed Smith-Rowland
0 siblings, 0 replies; 3+ messages in thread
From: Ed Smith-Rowland @ 2014-12-24 2:17 UTC (permalink / raw)
To: gcc-patches, Jason Merrill, NightStrike
[-- Attachment #1: Type: text/plain, Size: 490 bytes --]
And now with a patch...
I tried this patch a year ago and, as pointed out by NightStrike, got
lost in the shuffle.
The idea is that default arguments in literal operators would lead to
ambiguities and might not act like the uthor intends.
The earlier patch errors out. This time I just warn. I'm not sure what
we want here actually so some feedback would be nice.
I could alternatively error and add a note about default argument.
Builds and tests clean on x86_64-linux.
OK?
Ed
[-- Attachment #2: CL_udlit_defarg3 --]
[-- Type: text/plain, Size: 586 bytes --]
cp:
2014-12-23 Edward Smith-Rowland <3dw4rd@verizon.net>
DR1479: Literal operators and default arguments
* cp-tree.h (check_literal_operator_args): Add new variable.
* decl.c (grokfndecl): Adjust call. Report extra error.
* typeck.c (check_literal_operator_args): Add and set new return
argument indicating defaulted operator argument.
of character and build parm pack with correct type and chars.
testsuite:
2014-12-23 Edward Smith-Rowland <3dw4rd@verizon.net>
DR1479: Literal operators and default arguments
* testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C: New.
[-- Attachment #3: patch_udlit_defarg3 --]
[-- Type: text/plain, Size: 3657 bytes --]
Index: cp/cp-tree.h
===================================================================
--- cp/cp-tree.h (revision 218988)
+++ cp/cp-tree.h (working copy)
@@ -6286,7 +6286,7 @@
tsubst_flags_t);
extern void check_template_keyword (tree);
extern bool check_raw_literal_operator (const_tree decl);
-extern bool check_literal_operator_args (const_tree, bool *, bool *);
+extern bool check_literal_operator_args (const_tree, bool *, bool *, bool *);
extern void maybe_warn_about_useless_cast (tree, tree, tsubst_flags_t);
extern tree cp_perform_integral_promotions (tree, tsubst_flags_t);
Index: cp/decl.c
===================================================================
--- cp/decl.c (revision 218988)
+++ cp/decl.c (working copy)
@@ -7849,6 +7849,7 @@
return NULL_TREE;
else if (UDLIT_OPER_P (DECL_NAME (decl)))
{
+ bool default_arg_p;
bool long_long_unsigned_p;
bool long_double_p;
const char *suffix = NULL;
@@ -7861,12 +7862,15 @@
if (DECL_NAMESPACE_SCOPE_P (decl))
{
- if (!check_literal_operator_args (decl, &long_long_unsigned_p,
+ if (!check_literal_operator_args (decl, &default_arg_p,
+ &long_long_unsigned_p,
&long_double_p))
{
error ("%qD has invalid argument list", decl);
return NULL_TREE;
}
+ if (default_arg_p)
+ warning (0, "%qD has default argument(s)", decl);
suffix = UDLIT_OP_SUFFIX (DECL_NAME (decl));
if (long_long_unsigned_p)
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 218988)
+++ cp/typeck.c (working copy)
@@ -9204,15 +9204,21 @@
argument types. */
bool
-check_literal_operator_args (const_tree decl,
+check_literal_operator_args (const_tree decl, bool *default_arg_p,
bool *long_long_unsigned_p, bool *long_double_p)
{
tree argtypes = TYPE_ARG_TYPES (TREE_TYPE (decl));
+ *default_arg_p = false;
*long_long_unsigned_p = false;
*long_double_p = false;
if (processing_template_decl || processing_specialization)
- return argtypes == void_list_node;
+ {
+ if (argtypes && argtypes != void_list_node && TREE_PURPOSE (argtypes))
+ *default_arg_p = true;
+
+ return argtypes == void_list_node;
+ }
else
{
tree argtype;
@@ -9224,6 +9230,9 @@
argtype && argtype != void_list_node;
argtype = TREE_CHAIN (argtype))
{
+ if (TREE_PURPOSE (argtype))
+ *default_arg_p = true;
+
tree t = TREE_VALUE (argtype);
++arity;
@@ -9242,6 +9251,8 @@
argtype = TREE_CHAIN (argtype);
if (!argtype)
return false;
+ if (TREE_PURPOSE (argtype))
+ *default_arg_p = true;
t = TREE_VALUE (argtype);
if (maybe_raw_p && argtype == void_list_node)
return true;
@@ -9278,6 +9289,9 @@
if (!argtype)
return false; /* Found ellipsis. */
+ if (*default_arg_p)
+ return false;
+
if (arity != max_arity)
return false;
Index: testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C
===================================================================
--- testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C (revision 0)
+++ testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C (working copy)
@@ -0,0 +1,22 @@
+// { dg-options -std=c++11 }
+
+#include <cstddef>
+
+int
+operator""_a(const char *, std::size_t = 0) // { dg-warning "has invalid argument list" }
+{
+ return 1;
+}
+
+int
+operator""_a(const char *)
+{
+ return 2;
+}
+
+int
+main()
+{
+ int i = 123_a; // OK, raw literal, not ambiguous.
+ int j = operator""_a("123"); // OK, raw literal, not ambiguous.
+}
^ permalink raw reply [flat|nested] 3+ messages in thread
* [C++11] DR1479 - Literal operators and default arguments
@ 2013-12-05 19:55 Ed Smith-Rowland
0 siblings, 0 replies; 3+ messages in thread
From: Ed Smith-Rowland @ 2013-12-05 19:55 UTC (permalink / raw)
To: gcc-patches, jason
[-- Attachment #1: Type: text/plain, Size: 231 bytes --]
This patch rejects literal operators with defaulted arguments with an extra note to that effect. Not a big deal but it responds to a "malformed program" statement in the draft.
Builds and tests clean on x86_64-linux. OK?
Ed
[-- Attachment #2: CL_udlit_nodefault --]
[-- Type: application/octet-stream, Size: 586 bytes --]
cp:
2013-12-05 Edward Smith-Rowland <3dw4rd@verizon.net>
DR1479: Literal operators and default arguments
* cp-tree.h (check_literal_operator_args): Add new variable.
* decl.c (grokfndecl): Adjust call. Report extra error.
* typeck.c (check_literal_operator_args): Add and set new return
argument indicating defaulted operator argument.
of character and build parm pack with correct type and chars.
testsuite:
2013-12-05 Edward Smith-Rowland <3dw4rd@verizon.net>
DR1479: Literal operators and default arguments
* testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C: New.
[-- Attachment #3: patch_udlit_nodefault --]
[-- Type: application/octet-stream, Size: 3585 bytes --]
Index: cp/cp-tree.h
===================================================================
--- cp/cp-tree.h (revision 205641)
+++ cp/cp-tree.h (working copy)
@@ -6090,7 +6090,7 @@
tsubst_flags_t);
extern void check_template_keyword (tree);
extern bool check_raw_literal_operator (const_tree decl);
-extern bool check_literal_operator_args (const_tree, bool *, bool *);
+extern bool check_literal_operator_args (const_tree, bool *, bool *, bool *);
extern void maybe_warn_about_useless_cast (tree, tree, tsubst_flags_t);
extern tree cp_perform_integral_promotions (tree, tsubst_flags_t);
Index: cp/decl.c
===================================================================
--- cp/decl.c (revision 205641)
+++ cp/decl.c (working copy)
@@ -7618,6 +7618,7 @@
return NULL_TREE;
else if (UDLIT_OPER_P (DECL_NAME (decl)))
{
+ bool default_arg_p;
bool long_long_unsigned_p;
bool long_double_p;
const char *suffix = NULL;
@@ -7630,10 +7631,13 @@
if (DECL_NAMESPACE_SCOPE_P (decl))
{
- if (!check_literal_operator_args (decl, &long_long_unsigned_p,
+ if (!check_literal_operator_args (decl, &default_arg_p,
+ &long_long_unsigned_p,
&long_double_p))
{
error ("%qD has invalid argument list", decl);
+ if (default_arg_p)
+ inform (input_location, "%qD has default argument(s)", decl);
return NULL_TREE;
}
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 205641)
+++ cp/typeck.c (working copy)
@@ -9061,15 +9061,20 @@
argument types. */
bool
-check_literal_operator_args (const_tree decl,
+check_literal_operator_args (const_tree decl, bool *default_arg_p,
bool *long_long_unsigned_p, bool *long_double_p)
{
tree argtypes = TYPE_ARG_TYPES (TREE_TYPE (decl));
+ *default_arg_p = false;
*long_long_unsigned_p = false;
*long_double_p = false;
if (processing_template_decl || processing_specialization)
- return argtypes == void_list_node;
+ {
+ if (argtypes && argtypes != void_list_node && TREE_PURPOSE (argtypes))
+ *default_arg_p = true;
+ return argtypes == void_list_node;
+ }
else
{
tree argtype;
@@ -9081,6 +9086,9 @@
argtype && argtype != void_list_node;
argtype = TREE_CHAIN (argtype))
{
+ if (TREE_PURPOSE (argtype))
+ *default_arg_p = true;
+
tree t = TREE_VALUE (argtype);
++arity;
@@ -9099,6 +9107,8 @@
argtype = TREE_CHAIN (argtype);
if (!argtype)
return false;
+ if (TREE_PURPOSE (argtype))
+ *default_arg_p = true;
t = TREE_VALUE (argtype);
if (maybe_raw_p && argtype == void_list_node)
return true;
@@ -9135,6 +9145,9 @@
if (!argtype)
return false; /* Found ellipsis. */
+ if (*default_arg_p)
+ return false;
+
if (arity != max_arity)
return false;
Index: testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C
===================================================================
--- testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C (revision 0)
+++ testsuite/g++.dg/cpp0x/udlit-default-arg-neg.C (revision 0)
@@ -0,0 +1,22 @@
+// { dg-options -std=c++11 }
+
+#include <cstddef>
+
+int
+operator""_a(const char *, std::size_t = 0) // { dg-error "has invalid argument list" }
+{
+ return 1;
+}
+
+int
+operator""_a(const char *)
+{
+ return 2;
+}
+
+int
+main()
+{
+ int i = 123_a; // OK, raw literal, not ambiguous.
+ int j = operator""_a("123"); // OK, raw literal, not ambiguous.
+}
^ permalink raw reply [flat|nested] 3+ messages in thread
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