* [PATCH] c++: some missing-SFINAE fixes
@ 2022-09-13 11:45 Patrick Palka
2022-09-13 12:53 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Patrick Palka @ 2022-09-13 11:45 UTC (permalink / raw)
To: gcc-patches; +Cc: jason, Patrick Palka
It looks like we aren't respecting SFINAE for:
* an invalid/non-constant conditional explicit-specifier
* a non-constant conditional noexcept-specifier
* a non-constant argument to __integer_pack
This patch fixes these issues in the usual way, by passing complain
and propagating error_mark_node appropriately.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?
gcc/cp/ChangeLog:
* decl.cc (build_explicit_specifier): Pass complain to
cxx_constant_value.
* except.cc (build_noexcept_spec): Likewise.
* pt.cc (expand_integer_pack): Likewise.
(tsubst_function_decl): Propagate error_mark_node returned
from build_explicit_specifier.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/noexcept-type26.C: New test.
* g++.dg/cpp2a/explicit19.C: New test.
* g++.dg/ext/integer-pack6.C: New test.
---
gcc/cp/decl.cc | 2 +-
gcc/cp/except.cc | 2 +-
gcc/cp/pt.cc | 6 ++++--
gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C | 12 ++++++++++++
gcc/testsuite/g++.dg/cpp2a/explicit19.C | 12 ++++++++++++
gcc/testsuite/g++.dg/ext/integer-pack6.C | 13 +++++++++++++
6 files changed, 43 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit19.C
create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack6.C
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 936f1cf0197..5404d7e084c 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t complain)
expr = build_converted_constant_bool_expr (expr, complain);
expr = instantiate_non_dependent_expr (expr, complain);
- expr = cxx_constant_value (expr);
+ expr = cxx_constant_value (expr, NULL_TREE, complain);
return expr;
}
diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
index 7fdbc747c22..4d7f0ce102d 100644
--- a/gcc/cp/except.cc
+++ b/gcc/cp/except.cc
@@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t complain)
{
expr = build_converted_constant_bool_expr (expr, complain);
expr = instantiate_non_dependent_expr (expr, complain);
- expr = cxx_constant_value (expr);
+ expr = cxx_constant_value (expr, NULL_TREE, complain);
}
if (TREE_CODE (expr) == INTEGER_CST)
{
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 1c6f4b84612..f16f5ffca20 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain,
else
{
hi = instantiate_non_dependent_expr (hi, complain);
- hi = cxx_constant_value (hi);
+ hi = cxx_constant_value (hi, NULL_TREE, complain);
int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
/* Calculate the largest value of len that won't make the size of the vec
@@ -14312,7 +14312,9 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
/*function_p=*/false,
/*i_c_e_p=*/true);
spec = build_explicit_specifier (spec, complain);
- if (instantiation_dependent_expression_p (spec))
+ if (spec == error_mark_node)
+ return error_mark_node;
+ else if (instantiation_dependent_expression_p (spec))
store_explicit_specifier (r, spec);
else
{
diff --git a/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
new file mode 100644
index 00000000000..73058395f0a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
@@ -0,0 +1,12 @@
+// Verify a non-constant conditional noexcept-specifier of a function type
+// is a SFINAE error.
+// { dg-do compile { target c++17 } }
+
+template<class T> void f(void() noexcept(T::value)) = delete;
+template<class T> void f(...);
+
+struct B { static bool value; };
+
+int main() {
+ f<B>(nullptr);
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit19.C b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
new file mode 100644
index 00000000000..47903813680
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
@@ -0,0 +1,12 @@
+// Verify a conditional explicit-specifier is a SFINAE context.
+// { dg-do compile { target c++20 } }
+
+struct A {
+ template<class T> explicit(T::value) A(T) = delete;
+ A(...);
+};
+
+struct B { static bool value; };
+
+A x(0);
+A y(B{});
diff --git a/gcc/testsuite/g++.dg/ext/integer-pack6.C b/gcc/testsuite/g++.dg/ext/integer-pack6.C
new file mode 100644
index 00000000000..7e16bc44b40
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/integer-pack6.C
@@ -0,0 +1,13 @@
+// Verify a non-constant argument to __integer_pack is a SFINAE error.
+// { dg-do compile { target c++11 } }
+
+template<int...> struct A { };
+
+template<class T> auto f(int) -> A<__integer_pack(T::value)...> = delete;
+template<class T> void f(...);
+
+struct B { static int value; };
+
+int main() {
+ f<B>(0);
+}
--
2.37.3.542.gdd3f6c4cae
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] c++: some missing-SFINAE fixes
2022-09-13 11:45 [PATCH] c++: some missing-SFINAE fixes Patrick Palka
@ 2022-09-13 12:53 ` Jason Merrill
2022-09-13 13:46 ` Patrick Palka
0 siblings, 1 reply; 4+ messages in thread
From: Jason Merrill @ 2022-09-13 12:53 UTC (permalink / raw)
To: Patrick Palka, gcc-patches
On 9/13/22 07:45, Patrick Palka wrote:
> It looks like we aren't respecting SFINAE for:
>
> * an invalid/non-constant conditional explicit-specifier
> * a non-constant conditional noexcept-specifier
> * a non-constant argument to __integer_pack
>
> This patch fixes these issues in the usual way, by passing complain
> and propagating error_mark_node appropriately.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?
>
> gcc/cp/ChangeLog:
>
> * decl.cc (build_explicit_specifier): Pass complain to
> cxx_constant_value.
> * except.cc (build_noexcept_spec): Likewise.
> * pt.cc (expand_integer_pack): Likewise.
> (tsubst_function_decl): Propagate error_mark_node returned
> from build_explicit_specifier.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp1z/noexcept-type26.C: New test.
> * g++.dg/cpp2a/explicit19.C: New test.
> * g++.dg/ext/integer-pack6.C: New test.
> ---
> gcc/cp/decl.cc | 2 +-
> gcc/cp/except.cc | 2 +-
> gcc/cp/pt.cc | 6 ++++--
> gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C | 12 ++++++++++++
> gcc/testsuite/g++.dg/cpp2a/explicit19.C | 12 ++++++++++++
> gcc/testsuite/g++.dg/ext/integer-pack6.C | 13 +++++++++++++
> 6 files changed, 43 insertions(+), 4 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit19.C
> create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack6.C
>
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 936f1cf0197..5404d7e084c 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t complain)
>
> expr = build_converted_constant_bool_expr (expr, complain);
> expr = instantiate_non_dependent_expr (expr, complain);
> - expr = cxx_constant_value (expr);
> + expr = cxx_constant_value (expr, NULL_TREE, complain);
The patch is OK, but perhaps we want another overload that omits the
object parameter?
> return expr;
> }
>
> diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
> index 7fdbc747c22..4d7f0ce102d 100644
> --- a/gcc/cp/except.cc
> +++ b/gcc/cp/except.cc
> @@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t complain)
> {
> expr = build_converted_constant_bool_expr (expr, complain);
> expr = instantiate_non_dependent_expr (expr, complain);
> - expr = cxx_constant_value (expr);
> + expr = cxx_constant_value (expr, NULL_TREE, complain);
> }
> if (TREE_CODE (expr) == INTEGER_CST)
> {
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 1c6f4b84612..f16f5ffca20 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain,
> else
> {
> hi = instantiate_non_dependent_expr (hi, complain);
> - hi = cxx_constant_value (hi);
> + hi = cxx_constant_value (hi, NULL_TREE, complain);
> int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
>
> /* Calculate the largest value of len that won't make the size of the vec
> @@ -14312,7 +14312,9 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
> /*function_p=*/false,
> /*i_c_e_p=*/true);
> spec = build_explicit_specifier (spec, complain);
> - if (instantiation_dependent_expression_p (spec))
> + if (spec == error_mark_node)
> + return error_mark_node;
> + else if (instantiation_dependent_expression_p (spec))
> store_explicit_specifier (r, spec);
> else
> {
> diff --git a/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> new file mode 100644
> index 00000000000..73058395f0a
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> @@ -0,0 +1,12 @@
> +// Verify a non-constant conditional noexcept-specifier of a function type
> +// is a SFINAE error.
> +// { dg-do compile { target c++17 } }
> +
> +template<class T> void f(void() noexcept(T::value)) = delete;
> +template<class T> void f(...);
> +
> +struct B { static bool value; };
> +
> +int main() {
> + f<B>(nullptr);
> +}
> diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit19.C b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
> new file mode 100644
> index 00000000000..47903813680
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
> @@ -0,0 +1,12 @@
> +// Verify a conditional explicit-specifier is a SFINAE context.
> +// { dg-do compile { target c++20 } }
> +
> +struct A {
> + template<class T> explicit(T::value) A(T) = delete;
> + A(...);
> +};
> +
> +struct B { static bool value; };
> +
> +A x(0);
> +A y(B{});
> diff --git a/gcc/testsuite/g++.dg/ext/integer-pack6.C b/gcc/testsuite/g++.dg/ext/integer-pack6.C
> new file mode 100644
> index 00000000000..7e16bc44b40
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ext/integer-pack6.C
> @@ -0,0 +1,13 @@
> +// Verify a non-constant argument to __integer_pack is a SFINAE error.
> +// { dg-do compile { target c++11 } }
> +
> +template<int...> struct A { };
> +
> +template<class T> auto f(int) -> A<__integer_pack(T::value)...> = delete;
> +template<class T> void f(...);
> +
> +struct B { static int value; };
> +
> +int main() {
> + f<B>(0);
> +}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] c++: some missing-SFINAE fixes
2022-09-13 12:53 ` Jason Merrill
@ 2022-09-13 13:46 ` Patrick Palka
2022-09-13 13:49 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Patrick Palka @ 2022-09-13 13:46 UTC (permalink / raw)
To: Jason Merrill; +Cc: Patrick Palka, gcc-patches
On Tue, 13 Sep 2022, Jason Merrill wrote:
> On 9/13/22 07:45, Patrick Palka wrote:
> > It looks like we aren't respecting SFINAE for:
> >
> > * an invalid/non-constant conditional explicit-specifier
> > * a non-constant conditional noexcept-specifier
> > * a non-constant argument to __integer_pack
> >
> > This patch fixes these issues in the usual way, by passing complain
> > and propagating error_mark_node appropriately.
> >
> > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> > trunk?
> >
> > gcc/cp/ChangeLog:
> >
> > * decl.cc (build_explicit_specifier): Pass complain to
> > cxx_constant_value.
> > * except.cc (build_noexcept_spec): Likewise.
> > * pt.cc (expand_integer_pack): Likewise.
> > (tsubst_function_decl): Propagate error_mark_node returned
> > from build_explicit_specifier.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/cpp1z/noexcept-type26.C: New test.
> > * g++.dg/cpp2a/explicit19.C: New test.
> > * g++.dg/ext/integer-pack6.C: New test.
> > ---
> > gcc/cp/decl.cc | 2 +-
> > gcc/cp/except.cc | 2 +-
> > gcc/cp/pt.cc | 6 ++++--
> > gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C | 12 ++++++++++++
> > gcc/testsuite/g++.dg/cpp2a/explicit19.C | 12 ++++++++++++
> > gcc/testsuite/g++.dg/ext/integer-pack6.C | 13 +++++++++++++
> > 6 files changed, 43 insertions(+), 4 deletions(-)
> > create mode 100644 gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> > create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit19.C
> > create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack6.C
> >
> > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> > index 936f1cf0197..5404d7e084c 100644
> > --- a/gcc/cp/decl.cc
> > +++ b/gcc/cp/decl.cc
> > @@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t
> > complain)
> > expr = build_converted_constant_bool_expr (expr, complain);
> > expr = instantiate_non_dependent_expr (expr, complain);
> > - expr = cxx_constant_value (expr);
> > + expr = cxx_constant_value (expr, NULL_TREE, complain);
>
> The patch is OK, but perhaps we want another overload that omits the object
> parameter?
Thanks -- sounds good, like the following incremental patch?
-- >8 --
Subject: [PATCH] c++: two-parameter version of cxx_constant_value
Since some callers need the complain parameter but not the object
parameter, let's introduce and use an overload of cxx_constant_value
that omits the latter.
gcc/cp/ChangeLog:
* cp-tree.h (cxx_constant_value): Define two-parameter version
that omits the object parameter.
* decl.cc (build_explicit_specifier): Omit NULL_TREE object
argument to cxx_constant_value.
* except.cc (build_noexcept_spec): Likewise.
* pt.cc (expand_integer_pack): Likewise.
(fold_targs_r): Likewise.
* semantics.cc (finish_if_stmt_cond): Likewise.
---
gcc/cp/cp-tree.h | 2 ++
gcc/cp/decl.cc | 2 +-
gcc/cp/except.cc | 2 +-
gcc/cp/pt.cc | 4 ++--
gcc/cp/semantics.cc | 2 +-
5 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 2ba44e80e20..1eb176d4a50 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -8414,6 +8414,8 @@ extern bool require_rvalue_constant_expression (tree);
extern bool require_potential_rvalue_constant_expression (tree);
extern tree cxx_constant_value (tree, tree = NULL_TREE,
tsubst_flags_t = tf_error);
+inline tree cxx_constant_value (tree t, tsubst_flags_t complain)
+{ return cxx_constant_value (t, NULL_TREE, complain); }
extern void cxx_constant_dtor (tree, tree);
extern tree cxx_constant_init (tree, tree = NULL_TREE);
extern tree maybe_constant_value (tree, tree = NULL_TREE, bool = false);
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 5404d7e084c..006e9affcba 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t complain)
expr = build_converted_constant_bool_expr (expr, complain);
expr = instantiate_non_dependent_expr (expr, complain);
- expr = cxx_constant_value (expr, NULL_TREE, complain);
+ expr = cxx_constant_value (expr, complain);
return expr;
}
diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
index 4d7f0ce102d..048612de400 100644
--- a/gcc/cp/except.cc
+++ b/gcc/cp/except.cc
@@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t complain)
{
expr = build_converted_constant_bool_expr (expr, complain);
expr = instantiate_non_dependent_expr (expr, complain);
- expr = cxx_constant_value (expr, NULL_TREE, complain);
+ expr = cxx_constant_value (expr, complain);
}
if (TREE_CODE (expr) == INTEGER_CST)
{
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 074179288b6..db4e808adec 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain,
else
{
hi = instantiate_non_dependent_expr (hi, complain);
- hi = cxx_constant_value (hi, NULL_TREE, complain);
+ hi = cxx_constant_value (hi, complain);
int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
/* Calculate the largest value of len that won't make the size of the vec
@@ -20121,7 +20121,7 @@ fold_targs_r (tree targs, tsubst_flags_t complain)
&& !glvalue_p (elt)
&& !TREE_CONSTANT (elt))
{
- elt = cxx_constant_value (elt, NULL_TREE, complain);
+ elt = cxx_constant_value (elt, complain);
if (elt == error_mark_node)
return false;
}
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 3edefb2fca2..4f189978484 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -1042,7 +1042,7 @@ finish_if_stmt_cond (tree orig_cond, tree if_stmt)
{
maybe_warn_for_constant_evaluated (cond, /*constexpr_if=*/true);
cond = instantiate_non_dependent_expr (cond);
- cond = cxx_constant_value (cond, NULL_TREE);
+ cond = cxx_constant_value (cond);
}
else
{
--
2.37.3.542.gdd3f6c4cae
>
> > return expr;
> > }
> > diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
> > index 7fdbc747c22..4d7f0ce102d 100644
> > --- a/gcc/cp/except.cc
> > +++ b/gcc/cp/except.cc
> > @@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t
> > complain)
> > {
> > expr = build_converted_constant_bool_expr (expr, complain);
> > expr = instantiate_non_dependent_expr (expr, complain);
> > - expr = cxx_constant_value (expr);
> > + expr = cxx_constant_value (expr, NULL_TREE, complain);
> > }
> > if (TREE_CODE (expr) == INTEGER_CST)
> > {
> > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> > index 1c6f4b84612..f16f5ffca20 100644
> > --- a/gcc/cp/pt.cc
> > +++ b/gcc/cp/pt.cc
> > @@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args,
> > tsubst_flags_t complain,
> > else
> > {
> > hi = instantiate_non_dependent_expr (hi, complain);
> > - hi = cxx_constant_value (hi);
> > + hi = cxx_constant_value (hi, NULL_TREE, complain);
> > int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
> > /* Calculate the largest value of len that won't make the size of
> > the vec
> > @@ -14312,7 +14312,9 @@ tsubst_function_decl (tree t, tree args,
> > tsubst_flags_t complain,
> > /*function_p=*/false,
> > /*i_c_e_p=*/true);
> > spec = build_explicit_specifier (spec, complain);
> > - if (instantiation_dependent_expression_p (spec))
> > + if (spec == error_mark_node)
> > + return error_mark_node;
> > + else if (instantiation_dependent_expression_p (spec))
> > store_explicit_specifier (r, spec);
> > else
> > {
> > diff --git a/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> > b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> > new file mode 100644
> > index 00000000000..73058395f0a
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
> > @@ -0,0 +1,12 @@
> > +// Verify a non-constant conditional noexcept-specifier of a function type
> > +// is a SFINAE error.
> > +// { dg-do compile { target c++17 } }
> > +
> > +template<class T> void f(void() noexcept(T::value)) = delete;
> > +template<class T> void f(...);
> > +
> > +struct B { static bool value; };
> > +
> > +int main() {
> > + f<B>(nullptr);
> > +}
> > diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit19.C
> > b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
> > new file mode 100644
> > index 00000000000..47903813680
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp2a/explicit19.C
> > @@ -0,0 +1,12 @@
> > +// Verify a conditional explicit-specifier is a SFINAE context.
> > +// { dg-do compile { target c++20 } }
> > +
> > +struct A {
> > + template<class T> explicit(T::value) A(T) = delete;
> > + A(...);
> > +};
> > +
> > +struct B { static bool value; };
> > +
> > +A x(0);
> > +A y(B{});
> > diff --git a/gcc/testsuite/g++.dg/ext/integer-pack6.C
> > b/gcc/testsuite/g++.dg/ext/integer-pack6.C
> > new file mode 100644
> > index 00000000000..7e16bc44b40
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/ext/integer-pack6.C
> > @@ -0,0 +1,13 @@
> > +// Verify a non-constant argument to __integer_pack is a SFINAE error.
> > +// { dg-do compile { target c++11 } }
> > +
> > +template<int...> struct A { };
> > +
> > +template<class T> auto f(int) -> A<__integer_pack(T::value)...> = delete;
> > +template<class T> void f(...);
> > +
> > +struct B { static int value; };
> > +
> > +int main() {
> > + f<B>(0);
> > +}
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] c++: some missing-SFINAE fixes
2022-09-13 13:46 ` Patrick Palka
@ 2022-09-13 13:49 ` Jason Merrill
0 siblings, 0 replies; 4+ messages in thread
From: Jason Merrill @ 2022-09-13 13:49 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches
On 9/13/22 09:46, Patrick Palka wrote:
> On Tue, 13 Sep 2022, Jason Merrill wrote:
>
>> On 9/13/22 07:45, Patrick Palka wrote:
>>> It looks like we aren't respecting SFINAE for:
>>>
>>> * an invalid/non-constant conditional explicit-specifier
>>> * a non-constant conditional noexcept-specifier
>>> * a non-constant argument to __integer_pack
>>>
>>> This patch fixes these issues in the usual way, by passing complain
>>> and propagating error_mark_node appropriately.
>>>
>>> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
>>> trunk?
>>>
>>> gcc/cp/ChangeLog:
>>>
>>> * decl.cc (build_explicit_specifier): Pass complain to
>>> cxx_constant_value.
>>> * except.cc (build_noexcept_spec): Likewise.
>>> * pt.cc (expand_integer_pack): Likewise.
>>> (tsubst_function_decl): Propagate error_mark_node returned
>>> from build_explicit_specifier.
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> * g++.dg/cpp1z/noexcept-type26.C: New test.
>>> * g++.dg/cpp2a/explicit19.C: New test.
>>> * g++.dg/ext/integer-pack6.C: New test.
>>> ---
>>> gcc/cp/decl.cc | 2 +-
>>> gcc/cp/except.cc | 2 +-
>>> gcc/cp/pt.cc | 6 ++++--
>>> gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C | 12 ++++++++++++
>>> gcc/testsuite/g++.dg/cpp2a/explicit19.C | 12 ++++++++++++
>>> gcc/testsuite/g++.dg/ext/integer-pack6.C | 13 +++++++++++++
>>> 6 files changed, 43 insertions(+), 4 deletions(-)
>>> create mode 100644 gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C
>>> create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit19.C
>>> create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack6.C
>>>
>>> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
>>> index 936f1cf0197..5404d7e084c 100644
>>> --- a/gcc/cp/decl.cc
>>> +++ b/gcc/cp/decl.cc
>>> @@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t
>>> complain)
>>> expr = build_converted_constant_bool_expr (expr, complain);
>>> expr = instantiate_non_dependent_expr (expr, complain);
>>> - expr = cxx_constant_value (expr);
>>> + expr = cxx_constant_value (expr, NULL_TREE, complain);
>>
>> The patch is OK, but perhaps we want another overload that omits the object
>> parameter?
>
> Thanks -- sounds good, like the following incremental patch?
OK.
> -- >8 --
>
> Subject: [PATCH] c++: two-parameter version of cxx_constant_value
>
> Since some callers need the complain parameter but not the object
> parameter, let's introduce and use an overload of cxx_constant_value
> that omits the latter.
>
> gcc/cp/ChangeLog:
>
> * cp-tree.h (cxx_constant_value): Define two-parameter version
> that omits the object parameter.
> * decl.cc (build_explicit_specifier): Omit NULL_TREE object
> argument to cxx_constant_value.
> * except.cc (build_noexcept_spec): Likewise.
> * pt.cc (expand_integer_pack): Likewise.
> (fold_targs_r): Likewise.
> * semantics.cc (finish_if_stmt_cond): Likewise.
> ---
> gcc/cp/cp-tree.h | 2 ++
> gcc/cp/decl.cc | 2 +-
> gcc/cp/except.cc | 2 +-
> gcc/cp/pt.cc | 4 ++--
> gcc/cp/semantics.cc | 2 +-
> 5 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
> index 2ba44e80e20..1eb176d4a50 100644
> --- a/gcc/cp/cp-tree.h
> +++ b/gcc/cp/cp-tree.h
> @@ -8414,6 +8414,8 @@ extern bool require_rvalue_constant_expression (tree);
> extern bool require_potential_rvalue_constant_expression (tree);
> extern tree cxx_constant_value (tree, tree = NULL_TREE,
> tsubst_flags_t = tf_error);
> +inline tree cxx_constant_value (tree t, tsubst_flags_t complain)
> +{ return cxx_constant_value (t, NULL_TREE, complain); }
> extern void cxx_constant_dtor (tree, tree);
> extern tree cxx_constant_init (tree, tree = NULL_TREE);
> extern tree maybe_constant_value (tree, tree = NULL_TREE, bool = false);
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 5404d7e084c..006e9affcba 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t complain)
>
> expr = build_converted_constant_bool_expr (expr, complain);
> expr = instantiate_non_dependent_expr (expr, complain);
> - expr = cxx_constant_value (expr, NULL_TREE, complain);
> + expr = cxx_constant_value (expr, complain);
> return expr;
> }
>
> diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
> index 4d7f0ce102d..048612de400 100644
> --- a/gcc/cp/except.cc
> +++ b/gcc/cp/except.cc
> @@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t complain)
> {
> expr = build_converted_constant_bool_expr (expr, complain);
> expr = instantiate_non_dependent_expr (expr, complain);
> - expr = cxx_constant_value (expr, NULL_TREE, complain);
> + expr = cxx_constant_value (expr, complain);
> }
> if (TREE_CODE (expr) == INTEGER_CST)
> {
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 074179288b6..db4e808adec 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain,
> else
> {
> hi = instantiate_non_dependent_expr (hi, complain);
> - hi = cxx_constant_value (hi, NULL_TREE, complain);
> + hi = cxx_constant_value (hi, complain);
> int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
>
> /* Calculate the largest value of len that won't make the size of the vec
> @@ -20121,7 +20121,7 @@ fold_targs_r (tree targs, tsubst_flags_t complain)
> && !glvalue_p (elt)
> && !TREE_CONSTANT (elt))
> {
> - elt = cxx_constant_value (elt, NULL_TREE, complain);
> + elt = cxx_constant_value (elt, complain);
> if (elt == error_mark_node)
> return false;
> }
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 3edefb2fca2..4f189978484 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -1042,7 +1042,7 @@ finish_if_stmt_cond (tree orig_cond, tree if_stmt)
> {
> maybe_warn_for_constant_evaluated (cond, /*constexpr_if=*/true);
> cond = instantiate_non_dependent_expr (cond);
> - cond = cxx_constant_value (cond, NULL_TREE);
> + cond = cxx_constant_value (cond);
> }
> else
> {
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-09-13 11:45 [PATCH] c++: some missing-SFINAE fixes Patrick Palka
2022-09-13 12:53 ` Jason Merrill
2022-09-13 13:46 ` Patrick Palka
2022-09-13 13:49 ` Jason Merrill
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