[pushed] c++: Check satisfaction before non-dep convs. [CWG2369]
Jason Merrill
jason@redhat.com
Wed Aug 19 20:53:05 GMT 2020
It's very hard to use concepts to protect a template from hard errors due to
unwanted instantiation if constraints aren't checked until after doing all
substitution and checking of non-dependent conversions.
It was pretty straightforward to insert the satisfaction check into the
logic, but I needed to make the 3-parameter version of
satisfy_declaration_constraints call push_tinst_level like the 2-parameter
version already does. For simplicity, I also made it add any needed outer
template arguments from the TEMPLATE_DECL to the args.
The testsuite changes are mostly because this change causes unsatisfaction
to cause deduction to fail rather than reject the candidate later in
overload resolution.
Tested x86_64-pc-linux-gnu, applying to trunk.
gcc/cp/ChangeLog:
DR 2369
* cp-tree.h (push_tinst_level, push_tinst_level_loc): Declare.
* constraint.cc (satisfy_declaration_constraints):
Use add_outermost_template_args and push_tinst_level.
* pt.c (add_outermost_template_args): Handle getting
a TEMPLATE_DECL as the first argument.
(push_tinst_level, push_tinst_level_loc): No longer static.
(fn_type_unification): Check satisfaction before non-dependent
conversions.
gcc/testsuite/ChangeLog:
DR 2369
* g++.dg/concepts/diagnostic10.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic13.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic2.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic3.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic4.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic5.C: Adjust expexcted errors.
* g++.dg/concepts/diagnostic9.C: Adjust expexcted errors.
* g++.dg/concepts/expression2.C: Adjust expexcted errors.
* g++.dg/concepts/fn5.C: Adjust expexcted errors.
* g++.dg/concepts/placeholder5.C: Adjust expexcted errors.
* g++.dg/concepts/pr67595.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-pr78752-2.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-pr84140.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-recursive-sat3.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-requires18.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-requires19.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts3.C: Adjust expexcted errors.
* g++.dg/cpp2a/concepts-nondep1.C: New test.
* g++.dg/cpp2a/concepts-nondep1a.C: New test.
---
gcc/cp/cp-tree.h | 2 ++
gcc/cp/constraint.cc | 12 +++++--
gcc/cp/pt.c | 35 +++++++++++++++----
gcc/testsuite/g++.dg/concepts/diagnostic10.C | 2 +-
gcc/testsuite/g++.dg/concepts/diagnostic13.C | 2 +-
gcc/testsuite/g++.dg/concepts/diagnostic2.C | 2 +-
gcc/testsuite/g++.dg/concepts/diagnostic3.C | 4 +--
gcc/testsuite/g++.dg/concepts/diagnostic4.C | 2 +-
gcc/testsuite/g++.dg/concepts/diagnostic5.C | 2 +-
gcc/testsuite/g++.dg/concepts/diagnostic9.C | 3 +-
gcc/testsuite/g++.dg/concepts/expression2.C | 2 +-
gcc/testsuite/g++.dg/concepts/fn5.C | 4 +--
gcc/testsuite/g++.dg/concepts/placeholder5.C | 4 +--
gcc/testsuite/g++.dg/concepts/pr67595.C | 2 +-
gcc/testsuite/g++.dg/cpp2a/concepts-nondep1.C | 19 ++++++++++
.../g++.dg/cpp2a/concepts-nondep1a.C | 20 +++++++++++
.../g++.dg/cpp2a/concepts-pr78752-2.C | 2 +-
gcc/testsuite/g++.dg/cpp2a/concepts-pr84140.C | 1 -
.../g++.dg/cpp2a/concepts-recursive-sat3.C | 2 +-
.../g++.dg/cpp2a/concepts-requires18.C | 4 +--
.../g++.dg/cpp2a/concepts-requires19.C | 12 +++----
gcc/testsuite/g++.dg/cpp2a/concepts3.C | 6 ++--
22 files changed, 106 insertions(+), 38 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-nondep1.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-nondep1a.C
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 44531cd86dc..3f3717a6bb5 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6981,7 +6981,9 @@ extern bool template_parm_object_p (const_tree);
extern tree tparm_object_argument (tree);
extern bool explicit_class_specialization_p (tree);
extern bool push_tinst_level (tree);
+extern bool push_tinst_level (tree, tree);
extern bool push_tinst_level_loc (tree, location_t);
+extern bool push_tinst_level_loc (tree, tree, location_t);
extern void pop_tinst_level (void);
extern struct tinst_level *outermost_tinst_level(void);
extern void init_template_processing (void);
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 48d52ec5b7a..7a2f3b9fde0 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -2814,16 +2814,22 @@ satisfy_declaration_constraints (tree t, tree args, subst_info info)
info.in_decl = t;
gcc_assert (TREE_CODE (t) == TEMPLATE_DECL);
+
+ args = add_outermost_template_args (t, args);
+
+ tree result = boolean_true_node;
if (tree norm = normalize_template_requirements (t, info.noisy ()))
{
+ if (!push_tinst_level (t, args))
+ return result;
tree pattern = DECL_TEMPLATE_RESULT (t);
push_access_scope (pattern);
- tree result = satisfy_associated_constraints (norm, args, info);
+ result = satisfy_associated_constraints (norm, args, info);
pop_access_scope (pattern);
- return result;
+ pop_tinst_level ();
}
- return boolean_true_node;
+ return result;
}
static tree
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index edaefcf505f..5dbdd37f6e3 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -586,13 +586,23 @@ add_to_template_args (tree args, tree extra_args)
(EXTRA_ARGS) levels are added. This function is used to combine
the template arguments from a partial instantiation with the
template arguments used to attain the full instantiation from the
- partial instantiation. */
+ partial instantiation.
+
+ If ARGS is a TEMPLATE_DECL, use its parameters as args. */
tree
add_outermost_template_args (tree args, tree extra_args)
{
tree new_args;
+ if (!args)
+ return extra_args;
+ if (TREE_CODE (args) == TEMPLATE_DECL)
+ {
+ tree ti = get_template_info (DECL_TEMPLATE_RESULT (args));
+ args = TI_ARGS (ti);
+ }
+
/* If there are more levels of EXTRA_ARGS than there are ARGS,
something very fishy is going on. */
gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
@@ -10772,7 +10782,7 @@ static GTY(()) struct tinst_level *last_error_tinst_level;
/* We're starting to instantiate D; record the template instantiation context
at LOC for diagnostics and to restore it later. */
-static bool
+bool
push_tinst_level_loc (tree tldcl, tree targs, location_t loc)
{
struct tinst_level *new_level;
@@ -10826,7 +10836,7 @@ push_tinst_level_loc (tree tldcl, tree targs, location_t loc)
/* We're starting substitution of TMPL<ARGS>; record the template
substitution context for diagnostics and to restore it later. */
-static bool
+bool
push_tinst_level (tree tmpl, tree args)
{
return push_tinst_level_loc (tmpl, args, input_location);
@@ -21297,13 +21307,24 @@ fn_type_unification (tree fn,
goto fail;
}
+ deduced:
+
+ /* CWG2369: Check satisfaction before non-deducible conversions. */
+ if (!constraints_satisfied_p (fn, targs))
+ {
+ if (explain_p)
+ diagnose_constraints (DECL_SOURCE_LOCATION (fn), fn, targs);
+ goto fail;
+ }
+
/* DR 1391: All parameters have args, now check non-dependent parms for
- convertibility. */
- if (check_non_deducible_conversions (parms, args, nargs, fn, strict, flags,
- convs, explain_p))
+ convertibility. We don't do this if all args were explicitly specified,
+ as the standard says that we substitute explicit args immediately. */
+ if (incomplete
+ && check_non_deducible_conversions (parms, args, nargs, fn, strict, flags,
+ convs, explain_p))
goto fail;
- deduced:
/* All is well so far. Now, check:
[temp.deduct]
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic10.C b/gcc/testsuite/g++.dg/concepts/diagnostic10.C
index fcc6043ca93..7a90b836143 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic10.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic10.C
@@ -14,5 +14,5 @@ struct S
void
bar()
{
- foo<S>(); // { dg-error "unsatisfied constraints" }
+ foo<S>(); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic13.C b/gcc/testsuite/g++.dg/concepts/diagnostic13.C
index accd8a6d2bd..1aff859f0bb 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic13.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic13.C
@@ -10,5 +10,5 @@ void foo() { }
void bar()
{
- foo<int, char>(); // { dg-error "unsatisfied constraints" }
+ foo<int, char>(); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic2.C b/gcc/testsuite/g++.dg/concepts/diagnostic2.C
index 47accb8366e..004c7a378e7 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic2.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic2.C
@@ -22,7 +22,7 @@ template<typename T>
void
baz()
{
- bar<int>(); // { dg-error "unsatisfied constraints" }
+ bar<int>(); // { dg-error "no match" }
/* { dg-begin-multiline-output "" }
bar<int>();
^
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic3.C b/gcc/testsuite/g++.dg/concepts/diagnostic3.C
index b4c75409b94..7796e264251 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic3.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic3.C
@@ -24,6 +24,6 @@ baz() // { dg-message "with Is = .2, 3, 4... evaluated to .false." }
void
baz()
{
- bar<int, char>(); // { dg-error "unsatisfied constraints" }
- baz<2,3,4>(); // { dg-error "unsatisfied constraints" }
+ bar<int, char>(); // { dg-error "no match" }
+ baz<2,3,4>(); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic4.C b/gcc/testsuite/g++.dg/concepts/diagnostic4.C
index 677bc867634..e38e35a4d00 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic4.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic4.C
@@ -15,4 +15,4 @@ template<typename T>
// { dg-message "typename remove_reference<T>::type" "" { target *-*-* } .-1 }
void foo() { }
-void bar() { foo<int> (); } // { dg-error "use of" }
+void bar() { foo<int> (); } // { dg-error "no match" }
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic5.C b/gcc/testsuite/g++.dg/concepts/diagnostic5.C
index 81705f6a0c6..70426ea3099 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic5.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic5.C
@@ -39,5 +39,5 @@ template<typename T>
void
bar()
{
- foo<char>(); // { dg-error "use of" }
+ foo<char>(); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/diagnostic9.C b/gcc/testsuite/g++.dg/concepts/diagnostic9.C
index 414b924f115..8eecfe6f81d 100644
--- a/gcc/testsuite/g++.dg/concepts/diagnostic9.C
+++ b/gcc/testsuite/g++.dg/concepts/diagnostic9.C
@@ -1,11 +1,12 @@
// PR c++/85278
// { dg-do compile { target concepts } }
+// { dg-message "candidate: .*const decltype\\(f2::a\\)&&" "" { target *-*-* } .+2 }
template<typename T>
void f2(T a)
requires requires (const decltype(a) &&x) { -x; }
{ }
int main() {
- f2<void*>(nullptr); // { dg-error "use of function .*const decltype\\(f2::a\\)&&" }
+ f2<void*>(nullptr); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/expression2.C b/gcc/testsuite/g++.dg/concepts/expression2.C
index 60dd5414461..4bb5bc71462 100644
--- a/gcc/testsuite/g++.dg/concepts/expression2.C
+++ b/gcc/testsuite/g++.dg/concepts/expression2.C
@@ -31,7 +31,7 @@ class S
int main()
{
- f1(s); // { dg-error "unsatisfied|private" }
+ f1(s); // { dg-error "no match" }
f2(s); // { dg-error "" }
// When used in non-SFINAE contexts, make sure that we fail
diff --git a/gcc/testsuite/g++.dg/concepts/fn5.C b/gcc/testsuite/g++.dg/concepts/fn5.C
index 6d86ac5d0af..bf277135e79 100644
--- a/gcc/testsuite/g++.dg/concepts/fn5.C
+++ b/gcc/testsuite/g++.dg/concepts/fn5.C
@@ -19,6 +19,6 @@ int main() {
S1<char> s1; // { dg-error "constraint|invalid" }
S2<int, char> s2; // { dg-error "constraint|invalid" }
- f('a'); // { dg-error "unsatisfied" }
- g(0, 'a'); // { dg-error "unsatisfied" }
+ f('a'); // { dg-error "no match" }
+ g(0, 'a'); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/concepts/placeholder5.C b/gcc/testsuite/g++.dg/concepts/placeholder5.C
index eccad65a301..3f29c933973 100644
--- a/gcc/testsuite/g++.dg/concepts/placeholder5.C
+++ b/gcc/testsuite/g++.dg/concepts/placeholder5.C
@@ -14,5 +14,5 @@ concept bool C =
template <C c>
constexpr bool f() { return true; }
-static_assert(f<double>(), ""); // { dg-error "unsatisfied|as type" }
-static_assert(f<int>(), ""); // { dg-error "unsatisfied|as type" }
+static_assert(f<double>(), ""); // { dg-error "no match" }
+static_assert(f<int>(), ""); // { dg-error "no match" }
diff --git a/gcc/testsuite/g++.dg/concepts/pr67595.C b/gcc/testsuite/g++.dg/concepts/pr67595.C
index 029ec7a1186..37adf931fb5 100644
--- a/gcc/testsuite/g++.dg/concepts/pr67595.C
+++ b/gcc/testsuite/g++.dg/concepts/pr67595.C
@@ -5,7 +5,7 @@ template <class X> concept bool allocatable = requires{{new X}->X *; };
template <class X> concept bool semiregular = allocatable<X>;
template <class X> concept bool readable = requires{requires semiregular<X>;};
template <class> int weak_input_iterator = requires{{0}->readable;};
-template <class X> bool input_iterator{weak_input_iterator<X>}; // { dg-warning "narrowing conversion" }
+template <class X> bool input_iterator{weak_input_iterator<X>}; // { dg-prune-output "narrowing conversion" }
template <class X> bool forward_iterator{input_iterator<X>};
template <class X> bool bidirectional_iterator{forward_iterator<X>};
template <class X>
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1.C b/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1.C
new file mode 100644
index 00000000000..5304b661d2a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1.C
@@ -0,0 +1,19 @@
+// DR 2369
+// { dg-do compile { target c++20 } }
+
+template <class T> struct Z {
+ typedef typename T::x xx;
+};
+template <class T> concept C = requires { typename T::A; };
+template <C T> typename Z<T>::xx f(void *, T); // #1
+template <class T> void f(int, T); // #2
+struct A {} a;
+struct ZZ {
+ template <class T, class = typename Z<T>::xx> operator T *();
+ operator int();
+};
+int main() {
+ ZZ zz;
+ f(1, a); // OK, deduction fails for #1 because there is no conversion from int to void*
+ f(zz, 42); // OK, deduction fails for #1 because C<int> is not satisfied
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1a.C b/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1a.C
new file mode 100644
index 00000000000..2ba4dbc84d6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-nondep1a.C
@@ -0,0 +1,20 @@
+// DR 2369
+// { dg-do compile { target c++20 } }
+
+template <class T> struct Z {
+ typedef typename T::x xx;
+};
+template <class T> concept C = requires { typename T::A; }; // { dg-message "T::A" }
+template <C T> typename Z<T>::xx f(void *, T); // { dg-message "not satisfied" }
+
+struct A {} a;
+struct ZZ {
+ template <class T, class = typename Z<T>::xx> operator T *();
+ operator int();
+};
+int main() {
+ ZZ zz;
+ f(1, a); // { dg-error "no match" } no conversion from int to void*
+ // { dg-message "cannot convert" "" { target *-*-* } .-1 }
+ f(zz, 42); // { dg-error "no match" } C<int> is not satisfied
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr78752-2.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78752-2.C
index 6777054285d..7d7c716cfec 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-pr78752-2.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78752-2.C
@@ -17,5 +17,5 @@ int main()
func(1, 2, 3);
t.func(1, 2, ""); // { dg-error "no match" }
- func(1, 2, ""); // { dg-error "unsatisfied constraints" }
+ func(1, 2, ""); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr84140.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr84140.C
index b604f7e00bf..7eff65bee9e 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-pr84140.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr84140.C
@@ -34,4 +34,3 @@ int main()
{
return distance(I<int>{}, I<void>{});
}
-
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-recursive-sat3.C b/gcc/testsuite/g++.dg/cpp2a/concepts-recursive-sat3.C
index 679f5cfbf69..b2a6a796ea7 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-recursive-sat3.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-recursive-sat3.C
@@ -8,5 +8,5 @@ void foo(T t) { }
void test()
{
- foo(0); // { dg-error "unsatisfied constraints" }
+ foo(0); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires18.C b/gcc/testsuite/g++.dg/cpp2a/concepts-requires18.C
index 9d8ec94f696..a9b7720cc6c 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-requires18.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires18.C
@@ -67,11 +67,11 @@ void test()
{
f1<int>();
f1<bool>();
- f1<void>(); // { dg-error "unsatisfied" }
+ f1<void>(); // { dg-error "no match" }
f2<int>();
f2<bool>();
- f2<void>(); // { dg-error "unsatisfied" }
+ f2<void>(); // { dg-error "no match" }
data<char> x;
x.f1<int>();
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires19.C b/gcc/testsuite/g++.dg/cpp2a/concepts-requires19.C
index b020250da50..68aeccf3197 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-requires19.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires19.C
@@ -47,12 +47,12 @@ void f6(T x) requires requires { requires check_v<decltype(x)>; } { }
void test()
{
- f1<int>(); // { dg-error "unsatisfied" }
- f2(0); // { dg-error "unsatisfied" }
+ f1<int>(); // { dg-error "no match" }
+ f2(0); // { dg-error "no match" }
- f3<int>(); // { dg-error "unsatisfied" }
- f4(0); // { dg-error "unsatisfied" }
+ f3<int>(); // { dg-error "no match" }
+ f4(0); // { dg-error "no match" }
- f5<int>(); // { dg-error "unsatisfied" }
- f6(0); // { dg-error "unsatisfied" }
+ f5<int>(); // { dg-error "no match" }
+ f6(0); // { dg-error "no match" }
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts3.C b/gcc/testsuite/g++.dg/cpp2a/concepts3.C
index 4ccfd0805b7..1e28e31ad88 100644
--- a/gcc/testsuite/g++.dg/cpp2a/concepts3.C
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts3.C
@@ -42,7 +42,7 @@ template<typename T>
void f3() { }
void driver2() {
- f1<S1>(); // { dg-error "unsatisfied|is private" }
- f2<S1>(); // { dg-error "unsatisfied|is private" }
- f3<S1>(); // { dg-error "unsatisfied|is private" }
+ f1<S1>(); // { dg-error "no match" }
+ f2<S1>(); // { dg-error "no match" }
+ f3<S1>(); // { dg-error "no match" }
}
base-commit: e6e01618e83bcd9eb3a2b27df30ed87106a748b4
--
2.18.1
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