Fix handling of thunks in ipa-modref

Thunks are not transparent for ipa-modref summary since it cares about offsets
from pointer parameters and also for virtual thunk about the read from memory
in there.  We however use function_or_virtual_thunk_symbol to get the summary
that may lead to wrong code (and does in two testsuite testcases with patch
I am working on).  This is a first aid fix that is bacportable to gcc 11.
We could easily produce summary for thunk on demand.  I will look into it
incrementally.  It is not very important since we usually inline the thunk when
we devirutalize...

Bootstrapped/regtested x86_64-linux, will commit it shortly.

gcc/ChangeLog:

2021-12-11  Jan Hubicka  <hubicka@ucw.cz>

	* ipa-modref.c (get_modref_function_summary): Use ultimate_alias_target.
	(ignore_edge): Likewise.
	(compute_parm_map): Likewise.
	(modref_propagate_in_scc): Likewise.
	(modref_propagate_flags_in_scc): Likewise.

diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index 9e537b0..55fa873 100644 (file)
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -754,7 +754,7 @@ get_modref_function_summary (cgraph_node *func)
      we don't want to return anything, even if we have summary for the target
      function.  */
   enum availability avail;
-  func = func->function_or_virtual_thunk_symbol
+  func = func->ultimate_alias_target
                 (&avail, current_function_decl ?
                          cgraph_node::get (current_function_decl) : NULL);
   if (avail <= AVAIL_INTERPOSABLE)
@@ -4065,7 +4065,7 @@ ignore_edge (struct cgraph_edge *e)
   if (!e->inline_failed)
     return false;
   enum availability avail;
-  cgraph_node *callee = e->callee->function_or_virtual_thunk_symbol
+  cgraph_node *callee = e->callee->ultimate_alias_target
                          (&avail, e->caller);
 
   return (avail <= AVAIL_INTERPOSABLE
@@ -4088,7 +4088,7 @@ compute_parm_map (cgraph_edge *callee_edge, vec<modref_parm_map> *parm_map)
       class ipa_call_summary *es
             = ipa_call_summaries->get (callee_edge);
       cgraph_node *callee
-        = callee_edge->callee->function_or_virtual_thunk_symbol
+        = callee_edge->callee->ultimate_alias_target
                              (NULL, callee_edge->caller);
 
       caller_parms_info
@@ -4578,7 +4578,7 @@ modref_propagate_in_scc (cgraph_node *component_node)
 
              /* Get the callee and its summary.  */
              enum availability avail;
-             callee = callee_edge->callee->function_or_virtual_thunk_symbol
+             callee = callee_edge->callee->ultimate_alias_target
                         (&avail, cur);
 
              /* It is not necessary to re-process calls outside of the
@@ -5021,7 +5021,7 @@ modref_propagate_flags_in_scc (cgraph_node *component_node)
 
              /* Get the callee and its summary.  */
              enum availability avail;
-             callee = callee_edge->callee->function_or_virtual_thunk_symbol
+             callee = callee_edge->callee->ultimate_alias_target
                         (&avail, cur);
 
              /* It is not necessary to re-process calls outside of the