[PR,c++/84968] reject stmt-exprs in noexcept constexprs

Message ID or4ll6x169.fsf@lxoliva.fsfla.org
State New
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  • [PR,c++/84968] reject stmt-exprs in noexcept constexprs
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Commit Message

Alexandre Oliva March 23, 2018, 3:27 p.m.
We reject extended statement-expressions in template parameters, so we
might as well reject them in constant expressions used in noexcept
specifications.

Regstrapped on i686- and x86_64-linux-gnu.  Ok to install?

for  gcc/cp/ChangeLog

	PR c++/84968
	* tree.c (strip_typedefs_expr): Reject STATEMENT_LISTs.

for  gcc/testsuite/ChangeLog

	PR c++/84968
	* g++.dg/eh/pr84968.C: New.
---
 gcc/cp/tree.c                     |    4 ++++
 gcc/testsuite/g++.dg/eh/pr84968.C |   15 +++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/eh/pr84968.C



-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer

Comments

Jason Merrill March 23, 2018, 4:29 p.m. | #1
OK.

On Fri, Mar 23, 2018 at 11:27 AM, Alexandre Oliva <aoliva@redhat.com> wrote:
> We reject extended statement-expressions in template parameters, so we

> might as well reject them in constant expressions used in noexcept

> specifications.

>

> Regstrapped on i686- and x86_64-linux-gnu.  Ok to install?

>

> for  gcc/cp/ChangeLog

>

>         PR c++/84968

>         * tree.c (strip_typedefs_expr): Reject STATEMENT_LISTs.

>

> for  gcc/testsuite/ChangeLog

>

>         PR c++/84968

>         * g++.dg/eh/pr84968.C: New.

> ---

>  gcc/cp/tree.c                     |    4 ++++

>  gcc/testsuite/g++.dg/eh/pr84968.C |   15 +++++++++++++++

>  2 files changed, 19 insertions(+)

>  create mode 100644 gcc/testsuite/g++.dg/eh/pr84968.C

>

> diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c

> index f1a90bdec0fc..070bd11a0591 100644

> --- a/gcc/cp/tree.c

> +++ b/gcc/cp/tree.c

> @@ -1785,6 +1785,10 @@ strip_typedefs_expr (tree t, bool *remove_attributes)

>        error ("lambda-expression in a constant expression");

>        return error_mark_node;

>

> +    case STATEMENT_LIST:

> +      error ("statement-expression in a constant expression");

> +      return error_mark_node;

> +

>      default:

>        break;

>      }

> diff --git a/gcc/testsuite/g++.dg/eh/pr84968.C b/gcc/testsuite/g++.dg/eh/pr84968.C

> new file mode 100644

> index 000000000000..23c49f477a88

> --- /dev/null

> +++ b/gcc/testsuite/g++.dg/eh/pr84968.C

> @@ -0,0 +1,15 @@

> +// { dg-do compile { target c++11 } }

> +

> +// { dg-options "" }

> +

> +union b;

> +

> +struct S {

> +  template <typename>

> +  void a()

> +    try {

> +    } catch (int ()

> +            noexcept (({ union b a; true; }))) // { dg-error "constant" }

> +  {

> +  }

> +};

>

>

> --

> Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/

> You must be the change you wish to see in the world. -- Gandhi

> Be Free! -- http://FSFLA.org/   FSF Latin America board member

> Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer

Patch

diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index f1a90bdec0fc..070bd11a0591 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1785,6 +1785,10 @@  strip_typedefs_expr (tree t, bool *remove_attributes)
       error ("lambda-expression in a constant expression");
       return error_mark_node;
 
+    case STATEMENT_LIST:
+      error ("statement-expression in a constant expression");
+      return error_mark_node;
+
     default:
       break;
     }
diff --git a/gcc/testsuite/g++.dg/eh/pr84968.C b/gcc/testsuite/g++.dg/eh/pr84968.C
new file mode 100644
index 000000000000..23c49f477a88
--- /dev/null
+++ b/gcc/testsuite/g++.dg/eh/pr84968.C
@@ -0,0 +1,15 @@ 
+// { dg-do compile { target c++11 } }
+
+// { dg-options "" }
+
+union b;
+
+struct S {
+  template <typename>
+  void a()
+    try {
+    } catch (int ()
+	     noexcept (({ union b a; true; }))) // { dg-error "constant" }
+  {
+  }
+};