From aa701610e51ca9e15573ba080cb93ef726252cfc Mon Sep 17 00:00:00 2001
From: Jan Hubicka <jh@suse.cz>
Date: Fri, 30 Oct 2020 14:30:43 +0100
Subject: [PATCH] Fix thunk info WRT PCH

	PR pch/97593
	* cgraph.c (cgraph_node::create_thunk): Register thunk as early during
	parsing.
	* cgraphunit.c (analyze_functions): Call
	thunk_info::process_early_thunks.
	* symtab-thunks.cc (struct unprocessed_thunk): New struct.
	(thunks): New static variable.
	(thunk_info::register_early): New member function.
	(thunk_info::process_early_thunks): New member function.
	* symtab-thunks.h (thunk_info::register_early): Declare.
	(thunk_info::process_early_thunks): Declare.
---
 gcc/cgraph.c         |  9 ++++++++-
 gcc/cgraphunit.c     |  2 ++
 gcc/symtab-thunks.cc | 35 +++++++++++++++++++++++++++++++++++
 gcc/symtab-thunks.h  |  7 +++++++
 4 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d1a773d386f..9129bcf12d2 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -633,13 +633,20 @@ cgraph_node::create_thunk (tree alias, tree, bool this_adjusting,
   node->thunk = true;
   node->definition = true;
 
-  thunk_info *i = thunk_info::get_create (node);
+  thunk_info *i;
+  thunk_info local_info;
+  if (symtab->state < CONSTRUCTION)
+    i = &local_info;
+  else
+    i = thunk_info::get_create (node);
   i->fixed_offset = fixed_offset;
   i->virtual_value = virtual_value;
   i->indirect_offset = indirect_offset;
   i->alias = real_alias;
   i->this_adjusting = this_adjusting;
   i->virtual_offset_p = virtual_offset != NULL;
+  if (symtab->state < CONSTRUCTION)
+    i->register_early (node);
 
   return node;
 }
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 08b93cb00ee..3a9895825b1 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -1155,6 +1155,8 @@ analyze_functions (bool first_time)
   symtab->state = CONSTRUCTION;
   input_location = UNKNOWN_LOCATION;
 
+  thunk_info::process_early_thunks ();
+
   /* Ugly, but the fixup cannot happen at a time same body alias is created;
      C++ FE is confused about the COMDAT groups being right.  */
   if (symtab->cpp_implicit_aliases_done)
diff --git a/gcc/symtab-thunks.cc b/gcc/symtab-thunks.cc
index 1a4aaa2d80b..2199f4e6214 100644
--- a/gcc/symtab-thunks.cc
+++ b/gcc/symtab-thunks.cc
@@ -52,6 +52,14 @@ along with GCC; see the file COPYING3.  If not see
 
 /* Used for vtable lookup in thunk adjusting.  */
 static GTY (()) tree vtable_entry_type;
+struct GTY (()) unprocessed_thunk
+{
+  cgraph_node *node;
+  thunk_info *info;
+};
+/* To be PCH safe we store thunks into a vector before end of compilation
+   unit.  */
+static GTY (()) vec<unprocessed_thunk, va_gc> *thunks;
 
 namespace {
 
@@ -147,6 +155,33 @@ thunk_info::hash ()
   return hstate.end ();
 }
 
+/* Add unprocessed thunk.  */
+void
+thunk_info::register_early (cgraph_node *node)
+{
+  unprocessed_thunk entry = {node, new (ggc_alloc <thunk_info> ()) thunk_info};
+  *entry.info = *this;
+  vec_safe_push (thunks, entry);
+}
+
+/* Attach recorded thunks to cgraph_nodes.
+   All this is done only to avoid need to stream summaries to PCH.  */
+void
+thunk_info::process_early_thunks ()
+{
+  unprocessed_thunk *e;
+  unsigned int i;
+  if (!thunks)
+    return;
+
+  FOR_EACH_VEC_ELT (*thunks, i, e)
+    {
+      *thunk_info::get_create (e->node) = *e->info;
+    }
+  vec_free (thunks);
+  thunks = NULL;
+}
+
 /* Adjust PTR by the constant FIXED_OFFSET, by the vtable offset indicated by
    VIRTUAL_OFFSET, and by the indirect offset indicated by INDIRECT_OFFSET, if
    it is non-null. THIS_ADJUSTING is nonzero for a this adjusting thunk and zero
diff --git a/gcc/symtab-thunks.h b/gcc/symtab-thunks.h
index a23fc552950..41a684995b3 100644
--- a/gcc/symtab-thunks.h
+++ b/gcc/symtab-thunks.h
@@ -77,6 +77,7 @@ struct GTY(()) thunk_info {
     fixed_offset = other.fixed_offset;
     virtual_value = other.virtual_value;
     indirect_offset = other.indirect_offset;
+    alias = other.alias;
     this_adjusting = other.this_adjusting;
     virtual_offset_p = other.virtual_offset_p;
     return *this;
@@ -133,6 +134,12 @@ struct GTY(()) thunk_info {
   /* Remove thunk_info.  */
   static void remove (cgraph_node *node);
 
+  /* Add unprocessed thunk.  */
+  void register_early (cgraph_node *node);
+
+  /* Attach recorded thunks to cgraph_nodes.  */
+  static void process_early_thunks ();
+
   /* Release all thunk_infos.  */
   static void release (void);
 };
-- 
2.30.2