diff mbox series

[pushed] c++: array DMI and member fn [PR109666]

Message ID 20230501205454.1627105-1-jason@redhat.com
State New
Headers show
Series [pushed] c++: array DMI and member fn [PR109666] | expand

Commit Message

Jason Merrill May 1, 2023, 8:54 p.m. UTC 
Tested x86_64-pc-linux-gnu, applying to trunk.

Patrick, can you verify that this resolves 109506 and add whatever testcase(s)
seem appropriate from that PR?

-- 8< --

Here it turns out I also needed to adjust cfun when stepping out of the
member function to instantiate the DMI.  But instead of adding that tweak,
let's unify with instantiate_body and just push_to_top_level instead of
trying to do the minimum subset of it.  There was no measurable change in
compile time on stdc++.h.

This should also resolve 109506 without yet another tweak.

	PR c++/109666

gcc/cp/ChangeLog:

	* name-lookup.cc (maybe_push_to_top_level)
	(maybe_pop_from_top_level): Split out...
	* pt.cc (instantiate_body): ...from here.
	* init.cc (maybe_instantiate_nsdmi_init): Use them.
	* name-lookup.h: Declare them..

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/nsdmi-array2.C: New test.
---
 gcc/cp/name-lookup.h                      |  2 ++
 gcc/cp/init.cc                            | 25 ++-------------
 gcc/cp/name-lookup.cc                     | 37 +++++++++++++++++++++++
 gcc/cp/pt.cc                              | 20 ++----------
 gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C | 15 +++++++++
 5 files changed, 58 insertions(+), 41 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C


base-commit: 14e881eb0305090e5b184806b917d492373d32ea

Comments

Patrick Palka Dec. 19, 2023, 7:08 p.m. UTC | #1 
On Mon, 1 May 2023, Jason Merrill wrote:

> Tested x86_64-pc-linux-gnu, applying to trunk.
> 
> Patrick, can you verify that this resolves 109506 and add whatever testcase(s)
> seem appropriate from that PR?
> 
> -- 8< --
> 
> Here it turns out I also needed to adjust cfun when stepping out of the
> member function to instantiate the DMI.  But instead of adding that tweak,
> let's unify with instantiate_body and just push_to_top_level instead of
> trying to do the minimum subset of it.  There was no measurable change in
> compile time on stdc++.h.
> 
> This should also resolve 109506 without yet another tweak.
> 
> 	PR c++/109666
> 
> gcc/cp/ChangeLog:
> 
> 	* name-lookup.cc (maybe_push_to_top_level)
> 	(maybe_pop_from_top_level): Split out...
> 	* pt.cc (instantiate_body): ...from here.
> 	* init.cc (maybe_instantiate_nsdmi_init): Use them.
> 	* name-lookup.h: Declare them..
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/cpp0x/nsdmi-array2.C: New test.
> ---
>  gcc/cp/name-lookup.h                      |  2 ++
>  gcc/cp/init.cc                            | 25 ++-------------
>  gcc/cp/name-lookup.cc                     | 37 +++++++++++++++++++++++
>  gcc/cp/pt.cc                              | 20 ++----------
>  gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C | 15 +++++++++
>  5 files changed, 58 insertions(+), 41 deletions(-)
>  create mode 100644 gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C
> 
> diff --git a/gcc/cp/name-lookup.h b/gcc/cp/name-lookup.h
> index c234cd44356..b3e708561d8 100644
> --- a/gcc/cp/name-lookup.h
> +++ b/gcc/cp/name-lookup.h
> @@ -466,6 +466,8 @@ extern void push_nested_namespace (tree);
>  extern void pop_nested_namespace (tree);
>  extern void push_to_top_level (void);
>  extern void pop_from_top_level (void);
> +extern bool maybe_push_to_top_level (tree);
> +extern void maybe_pop_from_top_level (bool);
>  extern void push_using_decl_bindings (tree, tree);
>  
>  /* Lower level interface for modules. */
> diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
> index 1dd24e30d7c..0b35e1092e9 100644
> --- a/gcc/cp/init.cc
> +++ b/gcc/cp/init.cc
> @@ -597,32 +597,14 @@ maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
>  	  bool pushed = false;
>  	  tree ctx = type_context_for_name_lookup (member);
>  
> -	  processing_template_decl_sentinel ptds (/*reset*/false);
> +	  bool push_to_top = maybe_push_to_top_level (member);
>  	  if (!currently_open_class (ctx))
>  	    {
> -	      if (!LOCAL_CLASS_P (ctx))
> -		push_to_top_level ();
> -	      else
> -		/* push_to_top_level would lose the necessary function context,
> -		   just reset processing_template_decl.  */
> -		processing_template_decl = 0;
>  	      push_nested_class (ctx);
>  	      push_deferring_access_checks (dk_no_deferred);
>  	      pushed = true;
>  	    }
>  
> -	  /* If we didn't push_to_top_level, still step out of constructor
> -	     scope so build_base_path doesn't try to use its __in_chrg.  */
> -	  tree cfd = current_function_decl;
> -	  auto cbl = current_binding_level;
> -	  if (at_function_scope_p ())
> -	    {
> -	      current_function_decl
> -		= decl_function_context (current_function_decl);
> -	      while (current_binding_level->kind != sk_class)
> -		current_binding_level = current_binding_level->level_chain;
> -	    }
> -
>  	  inject_this_parameter (ctx, TYPE_UNQUALIFIED);
>  
>  	  start_lambda_scope (member);
> @@ -639,15 +621,12 @@ maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
>  	  if (init != error_mark_node)
>  	    DECL_INITIAL (member) = init;
>  
> -	  current_function_decl = cfd;
> -	  current_binding_level = cbl;
>  	  if (pushed)
>  	    {
>  	      pop_deferring_access_checks ();
>  	      pop_nested_class ();
> -	      if (!LOCAL_CLASS_P (ctx))
> -		pop_from_top_level ();
>  	    }
> +	  maybe_pop_from_top_level (push_to_top);
>  
>  	  input_location = sloc;
>  	}
> diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
> index 477cddd7543..7c61bc3bf61 100644
> --- a/gcc/cp/name-lookup.cc
> +++ b/gcc/cp/name-lookup.cc
> @@ -8236,6 +8236,43 @@ pop_from_top_level (void)
>    free_saved_scope = s;
>  }
>  
> +/* Like push_to_top_level, but not if D is function-local.  Returns whether we
> +   did push to top.  */
> +
> +bool
> +maybe_push_to_top_level (tree d)
> +{
> +  /* Push if D isn't function-local, or is a lambda function, for which name
> +     resolution is already done.  */
> +  bool push_to_top
> +    = !(current_function_decl
> +	&& !LAMBDA_FUNCTION_P (d)
> +	&& decl_function_context (d) == current_function_decl);
> +
> +  if (push_to_top)
> +    push_to_top_level ();
> +  else
> +    {
> +      gcc_assert (!processing_template_decl);
> +      push_function_context ();
> +      cp_unevaluated_operand = 0;
> +      c_inhibit_evaluation_warnings = 0;

I think we need to restore these flags in maybe_pop_from_top_level, like
so perhaps?  Bootstrap and regtest running on x86_64-pc-linux-gnu.

-- >8 --

Subject: [PATCH] c++: missing state restoration in maybe_pop_from_top_level

gcc/cp/ChangeLog:

	* name-lookup.cc (struct maybe_push_state_t): Define.
	(maybe_push_state_stack): Define.
	(maybe_push_to_top_level): Use them.
	(maybe_pop_from_top_level): Likewise.
	* pt.cc (instantiate_decl): Remove dead code for saving/restoring
	cp_unevaluated_operand and c_inhibit_evaluation_warnings.
---
 gcc/cp/name-lookup.cc | 37 ++++++++++++++++++++++++++++++++++---
 gcc/cp/pt.cc          |  4 ----
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 09dc6ef3e5a..aaedfaa45b3 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -8553,6 +8553,35 @@ pop_from_top_level (void)
   free_saved_scope = s;
 }
 
+/* Helper class for saving/restoring relevant global flags in the
+   function-local case of maybe_push_to_top_level.  */
+
+struct maybe_push_state_t
+{
+  int cp_unevaluated_operand;
+  int c_inhibit_evaluation_warnings;
+
+  static maybe_push_state_t
+  save_and_clear ()
+  {
+    maybe_push_state_t s;
+    s.cp_unevaluated_operand = ::cp_unevaluated_operand;
+    ::cp_unevaluated_operand = 0;
+    s.c_inhibit_evaluation_warnings = ::c_inhibit_evaluation_warnings;
+    ::c_inhibit_evaluation_warnings = 0;
+    return s;
+  }
+
+  void
+  restore () const
+  {
+    ::cp_unevaluated_operand = this->cp_unevaluated_operand;
+    ::c_inhibit_evaluation_warnings = this->c_inhibit_evaluation_warnings;
+  }
+};
+
+static vec<maybe_push_state_t> maybe_push_state_stack;
+
 /* Like push_to_top_level, but not if D is function-local.  Returns whether we
    did push to top.  */
 
@@ -8572,8 +8601,7 @@ maybe_push_to_top_level (tree d)
     {
       gcc_assert (!processing_template_decl);
       push_function_context ();
-      cp_unevaluated_operand = 0;
-      c_inhibit_evaluation_warnings = 0;
+      maybe_push_state_stack.safe_push (maybe_push_state_t::save_and_clear ());
     }
 
   return push_to_top;
@@ -8587,7 +8615,10 @@ maybe_pop_from_top_level (bool push_to_top)
   if (push_to_top)
     pop_from_top_level ();
   else
-    pop_function_context ();
+    {
+      maybe_push_state_stack.pop ().restore ();
+      pop_function_context ();
+    }
 }
 
 /* Push into the scope of the namespace NS, even if it is deeply
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index a82d7ae93aa..74da35596a5 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -26833,8 +26833,6 @@ instantiate_decl (tree d, bool defer_ok, bool expl_inst_class_mem_p)
   tree gen_tmpl;
   bool pattern_defined;
   location_t saved_loc = input_location;
-  int saved_unevaluated_operand = cp_unevaluated_operand;
-  int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
   bool external_p;
   bool deleted_p;
 
@@ -27071,8 +27069,6 @@ instantiate_decl (tree d, bool defer_ok, bool expl_inst_class_mem_p)
   pop_deferring_access_checks ();
   pop_tinst_level ();
   input_location = saved_loc;
-  cp_unevaluated_operand = saved_unevaluated_operand;
-  c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
 
   return d;
 }
Jason Merrill Dec. 19, 2023, 7:47 p.m. UTC | #2 
On 12/19/23 14:08, Patrick Palka wrote:
> On Mon, 1 May 2023, Jason Merrill wrote:
> 
>> Tested x86_64-pc-linux-gnu, applying to trunk.
>>
>> Patrick, can you verify that this resolves 109506 and add whatever testcase(s)
>> seem appropriate from that PR?
>>
>> -- 8< --
>>
>> Here it turns out I also needed to adjust cfun when stepping out of the
>> member function to instantiate the DMI.  But instead of adding that tweak,
>> let's unify with instantiate_body and just push_to_top_level instead of
>> trying to do the minimum subset of it.  There was no measurable change in
>> compile time on stdc++.h.
>>
>> This should also resolve 109506 without yet another tweak.
>>
>> 	PR c++/109666
>>
>> gcc/cp/ChangeLog:
>>
>> 	* name-lookup.cc (maybe_push_to_top_level)
>> 	(maybe_pop_from_top_level): Split out...
>> 	* pt.cc (instantiate_body): ...from here.
>> 	* init.cc (maybe_instantiate_nsdmi_init): Use them.
>> 	* name-lookup.h: Declare them..
>>
>> gcc/testsuite/ChangeLog:
>>
>> 	* g++.dg/cpp0x/nsdmi-array2.C: New test.
>> ---
>>   gcc/cp/name-lookup.h                      |  2 ++
>>   gcc/cp/init.cc                            | 25 ++-------------
>>   gcc/cp/name-lookup.cc                     | 37 +++++++++++++++++++++++
>>   gcc/cp/pt.cc                              | 20 ++----------
>>   gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C | 15 +++++++++
>>   5 files changed, 58 insertions(+), 41 deletions(-)
>>   create mode 100644 gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C
>>
>> diff --git a/gcc/cp/name-lookup.h b/gcc/cp/name-lookup.h
>> index c234cd44356..b3e708561d8 100644
>> --- a/gcc/cp/name-lookup.h
>> +++ b/gcc/cp/name-lookup.h
>> @@ -466,6 +466,8 @@ extern void push_nested_namespace (tree);
>>   extern void pop_nested_namespace (tree);
>>   extern void push_to_top_level (void);
>>   extern void pop_from_top_level (void);
>> +extern bool maybe_push_to_top_level (tree);
>> +extern void maybe_pop_from_top_level (bool);
>>   extern void push_using_decl_bindings (tree, tree);
>>   
>>   /* Lower level interface for modules. */
>> diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
>> index 1dd24e30d7c..0b35e1092e9 100644
>> --- a/gcc/cp/init.cc
>> +++ b/gcc/cp/init.cc
>> @@ -597,32 +597,14 @@ maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
>>   	  bool pushed = false;
>>   	  tree ctx = type_context_for_name_lookup (member);
>>   
>> -	  processing_template_decl_sentinel ptds (/*reset*/false);
>> +	  bool push_to_top = maybe_push_to_top_level (member);
>>   	  if (!currently_open_class (ctx))
>>   	    {
>> -	      if (!LOCAL_CLASS_P (ctx))
>> -		push_to_top_level ();
>> -	      else
>> -		/* push_to_top_level would lose the necessary function context,
>> -		   just reset processing_template_decl.  */
>> -		processing_template_decl = 0;
>>   	      push_nested_class (ctx);
>>   	      push_deferring_access_checks (dk_no_deferred);
>>   	      pushed = true;
>>   	    }
>>   
>> -	  /* If we didn't push_to_top_level, still step out of constructor
>> -	     scope so build_base_path doesn't try to use its __in_chrg.  */
>> -	  tree cfd = current_function_decl;
>> -	  auto cbl = current_binding_level;
>> -	  if (at_function_scope_p ())
>> -	    {
>> -	      current_function_decl
>> -		= decl_function_context (current_function_decl);
>> -	      while (current_binding_level->kind != sk_class)
>> -		current_binding_level = current_binding_level->level_chain;
>> -	    }
>> -
>>   	  inject_this_parameter (ctx, TYPE_UNQUALIFIED);
>>   
>>   	  start_lambda_scope (member);
>> @@ -639,15 +621,12 @@ maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
>>   	  if (init != error_mark_node)
>>   	    DECL_INITIAL (member) = init;
>>   
>> -	  current_function_decl = cfd;
>> -	  current_binding_level = cbl;
>>   	  if (pushed)
>>   	    {
>>   	      pop_deferring_access_checks ();
>>   	      pop_nested_class ();
>> -	      if (!LOCAL_CLASS_P (ctx))
>> -		pop_from_top_level ();
>>   	    }
>> +	  maybe_pop_from_top_level (push_to_top);
>>   
>>   	  input_location = sloc;
>>   	}
>> diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
>> index 477cddd7543..7c61bc3bf61 100644
>> --- a/gcc/cp/name-lookup.cc
>> +++ b/gcc/cp/name-lookup.cc
>> @@ -8236,6 +8236,43 @@ pop_from_top_level (void)
>>     free_saved_scope = s;
>>   }
>>   
>> +/* Like push_to_top_level, but not if D is function-local.  Returns whether we
>> +   did push to top.  */
>> +
>> +bool
>> +maybe_push_to_top_level (tree d)
>> +{
>> +  /* Push if D isn't function-local, or is a lambda function, for which name
>> +     resolution is already done.  */
>> +  bool push_to_top
>> +    = !(current_function_decl
>> +	&& !LAMBDA_FUNCTION_P (d)
>> +	&& decl_function_context (d) == current_function_decl);
>> +
>> +  if (push_to_top)
>> +    push_to_top_level ();
>> +  else
>> +    {
>> +      gcc_assert (!processing_template_decl);
>> +      push_function_context ();
>> +      cp_unevaluated_operand = 0;
>> +      c_inhibit_evaluation_warnings = 0;
> 
> I think we need to restore these flags in maybe_pop_from_top_level, like
> so perhaps?  Bootstrap and regtest running on x86_64-pc-linux-gnu.
> 
> -- >8 --
> 
> Subject: [PATCH] c++: missing state restoration in maybe_pop_from_top_level
> 
> gcc/cp/ChangeLog:
> 
> 	* name-lookup.cc (struct maybe_push_state_t): Define.
> 	(maybe_push_state_stack): Define.

I might call these local_state_t/local_state_stack since that's the case 
they're used for?  OK either way.

> 	(maybe_push_to_top_level): Use them.
> 	(maybe_pop_from_top_level): Likewise.
> 	* pt.cc (instantiate_decl): Remove dead code for saving/restoring
> 	cp_unevaluated_operand and c_inhibit_evaluation_warnings.
> ---
>   gcc/cp/name-lookup.cc | 37 ++++++++++++++++++++++++++++++++++---
>   gcc/cp/pt.cc          |  4 ----
>   2 files changed, 34 insertions(+), 7 deletions(-)
> 
> diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
> index 09dc6ef3e5a..aaedfaa45b3 100644
> --- a/gcc/cp/name-lookup.cc
> +++ b/gcc/cp/name-lookup.cc
> @@ -8553,6 +8553,35 @@ pop_from_top_level (void)
>     free_saved_scope = s;
>   }
>   
> +/* Helper class for saving/restoring relevant global flags in the
> +   function-local case of maybe_push_to_top_level.  */
> +
> +struct maybe_push_state_t
> +{
> +  int cp_unevaluated_operand;
> +  int c_inhibit_evaluation_warnings;
> +
> +  static maybe_push_state_t
> +  save_and_clear ()
> +  {
> +    maybe_push_state_t s;
> +    s.cp_unevaluated_operand = ::cp_unevaluated_operand;
> +    ::cp_unevaluated_operand = 0;
> +    s.c_inhibit_evaluation_warnings = ::c_inhibit_evaluation_warnings;
> +    ::c_inhibit_evaluation_warnings = 0;
> +    return s;
> +  }
> +
> +  void
> +  restore () const
> +  {
> +    ::cp_unevaluated_operand = this->cp_unevaluated_operand;
> +    ::c_inhibit_evaluation_warnings = this->c_inhibit_evaluation_warnings;
> +  }
> +};
> +
> +static vec<maybe_push_state_t> maybe_push_state_stack;
> +
>   /* Like push_to_top_level, but not if D is function-local.  Returns whether we
>      did push to top.  */
>   
> @@ -8572,8 +8601,7 @@ maybe_push_to_top_level (tree d)
>       {
>         gcc_assert (!processing_template_decl);
>         push_function_context ();
> -      cp_unevaluated_operand = 0;
> -      c_inhibit_evaluation_warnings = 0;
> +      maybe_push_state_stack.safe_push (maybe_push_state_t::save_and_clear ());
>       }
>   
>     return push_to_top;
> @@ -8587,7 +8615,10 @@ maybe_pop_from_top_level (bool push_to_top)
>     if (push_to_top)
>       pop_from_top_level ();
>     else
> -    pop_function_context ();
> +    {
> +      maybe_push_state_stack.pop ().restore ();
> +      pop_function_context ();
> +    }
>   }
>   
>   /* Push into the scope of the namespace NS, even if it is deeply
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index a82d7ae93aa..74da35596a5 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -26833,8 +26833,6 @@ instantiate_decl (tree d, bool defer_ok, bool expl_inst_class_mem_p)
>     tree gen_tmpl;
>     bool pattern_defined;
>     location_t saved_loc = input_location;
> -  int saved_unevaluated_operand = cp_unevaluated_operand;
> -  int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
>     bool external_p;
>     bool deleted_p;
>   
> @@ -27071,8 +27069,6 @@ instantiate_decl (tree d, bool defer_ok, bool expl_inst_class_mem_p)
>     pop_deferring_access_checks ();
>     pop_tinst_level ();
>     input_location = saved_loc;
> -  cp_unevaluated_operand = saved_unevaluated_operand;
> -  c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
>   
>     return d;
>   }
diff mbox series

Patch

diff --git a/gcc/cp/name-lookup.h b/gcc/cp/name-lookup.h
index c234cd44356..b3e708561d8 100644
--- a/gcc/cp/name-lookup.h
+++ b/gcc/cp/name-lookup.h
@@ -466,6 +466,8 @@  extern void push_nested_namespace (tree);
 extern void pop_nested_namespace (tree);
 extern void push_to_top_level (void);
 extern void pop_from_top_level (void);
+extern bool maybe_push_to_top_level (tree);
+extern void maybe_pop_from_top_level (bool);
 extern void push_using_decl_bindings (tree, tree);
 
 /* Lower level interface for modules. */
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 1dd24e30d7c..0b35e1092e9 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -597,32 +597,14 @@  maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
 	  bool pushed = false;
 	  tree ctx = type_context_for_name_lookup (member);
 
-	  processing_template_decl_sentinel ptds (/*reset*/false);
+	  bool push_to_top = maybe_push_to_top_level (member);
 	  if (!currently_open_class (ctx))
 	    {
-	      if (!LOCAL_CLASS_P (ctx))
-		push_to_top_level ();
-	      else
-		/* push_to_top_level would lose the necessary function context,
-		   just reset processing_template_decl.  */
-		processing_template_decl = 0;
 	      push_nested_class (ctx);
 	      push_deferring_access_checks (dk_no_deferred);
 	      pushed = true;
 	    }
 
-	  /* If we didn't push_to_top_level, still step out of constructor
-	     scope so build_base_path doesn't try to use its __in_chrg.  */
-	  tree cfd = current_function_decl;
-	  auto cbl = current_binding_level;
-	  if (at_function_scope_p ())
-	    {
-	      current_function_decl
-		= decl_function_context (current_function_decl);
-	      while (current_binding_level->kind != sk_class)
-		current_binding_level = current_binding_level->level_chain;
-	    }
-
 	  inject_this_parameter (ctx, TYPE_UNQUALIFIED);
 
 	  start_lambda_scope (member);
@@ -639,15 +621,12 @@  maybe_instantiate_nsdmi_init (tree member, tsubst_flags_t complain)
 	  if (init != error_mark_node)
 	    DECL_INITIAL (member) = init;
 
-	  current_function_decl = cfd;
-	  current_binding_level = cbl;
 	  if (pushed)
 	    {
 	      pop_deferring_access_checks ();
 	      pop_nested_class ();
-	      if (!LOCAL_CLASS_P (ctx))
-		pop_from_top_level ();
 	    }
+	  maybe_pop_from_top_level (push_to_top);
 
 	  input_location = sloc;
 	}
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 477cddd7543..7c61bc3bf61 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -8236,6 +8236,43 @@  pop_from_top_level (void)
   free_saved_scope = s;
 }
 
+/* Like push_to_top_level, but not if D is function-local.  Returns whether we
+   did push to top.  */
+
+bool
+maybe_push_to_top_level (tree d)
+{
+  /* Push if D isn't function-local, or is a lambda function, for which name
+     resolution is already done.  */
+  bool push_to_top
+    = !(current_function_decl
+	&& !LAMBDA_FUNCTION_P (d)
+	&& decl_function_context (d) == current_function_decl);
+
+  if (push_to_top)
+    push_to_top_level ();
+  else
+    {
+      gcc_assert (!processing_template_decl);
+      push_function_context ();
+      cp_unevaluated_operand = 0;
+      c_inhibit_evaluation_warnings = 0;
+    }
+
+  return push_to_top;
+}
+
+/* Return from whatever maybe_push_to_top_level did.  */
+
+void
+maybe_pop_from_top_level (bool push_to_top)
+{
+  if (push_to_top)
+    pop_from_top_level ();
+  else
+    pop_function_context ();
+}
+
 /* Push into the scope of the namespace NS, even if it is deeply
    nested within another namespace.  */
 
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 6df16fef0dd..3f1cf139bbd 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -26815,20 +26815,7 @@  instantiate_body (tree pattern, tree args, tree d, bool nested_p)
   if (current_function_decl)
     save_omp_privatization_clauses (omp_privatization_save);
 
-  bool push_to_top
-    = !(current_function_decl
-	&& !LAMBDA_FUNCTION_P (d)
-	&& decl_function_context (d) == current_function_decl);
-
-  if (push_to_top)
-    push_to_top_level ();
-  else
-    {
-      gcc_assert (!processing_template_decl);
-      push_function_context ();
-      cp_unevaluated_operand = 0;
-      c_inhibit_evaluation_warnings = 0;
-    }
+  bool push_to_top = maybe_push_to_top_level (d);
 
   mark_template_arguments_used (pattern, args);
 
@@ -26942,10 +26929,7 @@  instantiate_body (tree pattern, tree args, tree d, bool nested_p)
   if (!nested_p)
     TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
 
-  if (push_to_top)
-    pop_from_top_level ();
-  else
-    pop_function_context ();
+  maybe_pop_from_top_level (push_to_top);
 
   if (current_function_decl)
     restore_omp_privatization_clauses (omp_privatization_save);
diff --git a/gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C b/gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C
new file mode 100644
index 00000000000..5ad60f56510
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/nsdmi-array2.C
@@ -0,0 +1,15 @@ 
+// PR c++/109666
+// { dg-do compile { target c++11 } }
+
+struct Point {
+  int value_;
+};
+template <int n> struct StaticVector {
+  static StaticVector create() {
+    StaticVector output;
+    return output;
+  }
+  Point _M_elems[n]{};
+
+};
+void f() { StaticVector<3>::create(); }