From: Jason Merrill <jason@redhat.com>
Date: Sat, 15 Nov 2025 17:43:37 +0000 (+0530)
Subject: c++/modules: explicit inst of constructor
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c38bf35f0c7fa1dadaae4c2811b24aa4cd764cab;p=thirdparty%2Fgcc.git

c++/modules: explicit inst of constructor

The extern template __shared_ptr<filesystem::_Dir> in bits/fs_dir.h was
leading to an ICE in import_export_decl in 29_atomics/atomic_ref/address.cc
because we had the nonsensical combination of DECL_REALLY_EXTERN and
!DECL_INTERFACE_KNOWN.  This turned out to be because mark_decl_instantiated
was exiting early if TREE_ASM_WRITTEN since way back in the pre-cgraph days,
and expand_or_defer_fn_1 sets TREE_ASM_WRITTEN on maybe-in-charge ctors.
The mark_decl_instantiated code is long-obsolete, so let's just remove it.

gcc/cp/ChangeLog:

	* module.cc (trees_out::write_function_def): Check flag consistency.
	* pt.cc (mark_decl_instantiated): Ignore TREE_ASM_WRITTEN.
---

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 45a0309b86e..48ee7d1e790 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -12914,6 +12914,13 @@ trees_out::write_function_def (tree decl)
 		    && (get_importer_interface (decl)
 			!= importer_interface::external));
 
+      /* Make sure DECL_REALLY_EXTERN and DECL_INTERFACE_KNOWN are consistent
+	 on non-templates or we'll crash later in import_export_decl.  */
+      gcc_checking_assert (flags || DECL_INTERFACE_KNOWN (decl)
+			   || (DECL_LANG_SPECIFIC (decl)
+			       && DECL_TEMPLATE_INFO (decl)
+			       && uses_template_parms (DECL_TI_ARGS (decl))));
+
       if (f)
 	{
 	  flags |= 2;
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index b10442b0960..3b581b3fd36 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -26379,11 +26379,6 @@ mark_decl_instantiated (tree result, int extern_p)
 {
   SET_DECL_EXPLICIT_INSTANTIATION (result);
 
-  /* If this entity has already been written out, it's too late to
-     make any modifications.  */
-  if (TREE_ASM_WRITTEN (result))
-    return;
-
   /* consteval functions are never emitted.  */
   if (TREE_CODE (result) == FUNCTION_DECL
       && DECL_IMMEDIATE_FUNCTION_P (result))