Re: [pushed] c++: __integer_pack with class argument [PR111357]

[Jakub Jelinek via Gcc-patches]

On Tue, Sep 12, 2023 at 01:34:43PM -0400, Marek Polacek via Gcc-patches wrote:
> On Tue, Sep 12, 2023 at 01:27:44PM -0400, Jason Merrill via Gcc-patches wrote:
> > Tested x86_64-pc-linux-gnu, applying to trunk.
> > 
> > -- 8< --
> > 
> > The argument might not already be an integer.
> > 
> > PR c++/111357
> > 
> > gcc/cp/ChangeLog:
> > 
> > * pt.cc (expand_integer_pack): Convert argument to int.
> > 
> > gcc/testsuite/ChangeLog:
> > 
> > * g++.dg/ext/integer-pack7.C: New test.
> > ---
> >  gcc/cp/pt.cc |  2 ++
> >  gcc/testsuite/g++.dg/ext/integer-pack7.C | 38 
> >  2 files changed, 40 insertions(+)
> >  create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack7.C
> > 
> > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> > index 838179d5fe3..b583c11eb99 100644
> > --- a/gcc/cp/pt.cc
> > +++ b/gcc/cp/pt.cc
> > @@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, 
> > tsubst_flags_t complain,
> >  }
> >else
> >  {
> > +  hi = perform_implicit_conversion_flags (integer_type_node, hi, 
> > complain,
> > + LOOKUP_IMPLICIT);
> 
> FWIW, we have perform_implicit_conversion for this.

Is it correct to convert exactly to integer_type_node though?
Consider
#include 

using std::integer_sequence;
using std::make_integer_sequence;

template
void g(integer_sequence)
{}

template
struct c1
{
  static constexpr int value = 1;
  constexpr operator int() { return value; } 
  constexpr operator long() { return value + 1; }
};
template
struct R
{
using S = make_integer_sequence{}>;

R() noexcept(noexcept(g(S(
{}
};
int main()
{
R();
}
Shouldn't that invoke c1{}.operator long() rather than operator int()?
I thought the conversion was supposed to be done a few lines earlier,
instead of doing
  CALL_EXPR_ARG (call, 0) = hi;
do
  CALL_EXPR_ARG (call, 0)
= perform_implicit_conversion_flags (TREE_TYPE (ohi), hi,
 complain, LOOKUP_IMPLICIT);
or tsubst that TREE_TYPE (ohi) as well?  I.e. convert to type of the
template parameter.

Jakub

Re: [pushed] c++: __integer_pack with class argument [PR111357]

[Marek Polacek via Gcc-patches]

On Tue, Sep 12, 2023 at 01:27:44PM -0400, Jason Merrill via Gcc-patches wrote:
> Tested x86_64-pc-linux-gnu, applying to trunk.
> 
> -- 8< --
> 
> The argument might not already be an integer.
> 
>   PR c++/111357
> 
> gcc/cp/ChangeLog:
> 
>   * pt.cc (expand_integer_pack): Convert argument to int.
> 
> gcc/testsuite/ChangeLog:
> 
>   * g++.dg/ext/integer-pack7.C: New test.
> ---
>  gcc/cp/pt.cc |  2 ++
>  gcc/testsuite/g++.dg/ext/integer-pack7.C | 38 
>  2 files changed, 40 insertions(+)
>  create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack7.C
> 
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 838179d5fe3..b583c11eb99 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, 
> tsubst_flags_t complain,
>  }
>else
>  {
> +  hi = perform_implicit_conversion_flags (integer_type_node, hi, 
> complain,
> +   LOOKUP_IMPLICIT);

FWIW, we have perform_implicit_conversion for this.

Marek

[pushed] c++: __integer_pack with class argument [PR111357]

[Jason Merrill via Gcc-patches]

Tested x86_64-pc-linux-gnu, applying to trunk.

-- 8< --

The argument might not already be an integer.

PR c++/111357

gcc/cp/ChangeLog:

* pt.cc (expand_integer_pack): Convert argument to int.

gcc/testsuite/ChangeLog:

* g++.dg/ext/integer-pack7.C: New test.
---
 gcc/cp/pt.cc |  2 ++
 gcc/testsuite/g++.dg/ext/integer-pack7.C | 38 
 2 files changed, 40 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack7.C

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 838179d5fe3..b583c11eb99 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t 
complain,
 }
   else
 {
+  hi = perform_implicit_conversion_flags (integer_type_node, hi, complain,
+ LOOKUP_IMPLICIT);
   hi = instantiate_non_dependent_expr (hi, complain);
   hi = cxx_constant_value (hi, complain);
   int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
diff --git a/gcc/testsuite/g++.dg/ext/integer-pack7.C 
b/gcc/testsuite/g++.dg/ext/integer-pack7.C
new file mode 100644
index 000..95b1195bef4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/integer-pack7.C
@@ -0,0 +1,38 @@
+// PR c++/111357
+// { dg-do compile { target c++11 } }
+
+namespace std {
+  template
+struct integer_sequence
+{ };
+
+  template
+using make_integer_sequence
+  = integer_sequence<_Tp, __integer_pack(_Num)...>;
+}
+
+using std::integer_sequence;
+using std::make_integer_sequence;
+
+template
+void g(integer_sequence)
+{}
+
+template
+struct c1
+{
+  static constexpr int value = 1;
+  constexpr operator int() { return value; }
+};
+template
+struct R
+{
+   using S = make_integer_sequence{}>;
+
+   R() noexcept(noexcept(g(S(
+   {}
+};
+int main()
+{
+R();
+}

base-commit: ea5abbb263315e558c876b50c9371b90ddd5e028
-- 
2.39.3