[gcc(refs/users/marxin/heads/vect_cond_expr-rework-v3)] Fix cgraph_node::function_symbol availability compuattion [PR94202]

[Martin Liska]

https://gcc.gnu.org/g:f7dceb4e658399edfbf8dd0e08ce0c686bfa2c9d

commit f7dceb4e658399edfbf8dd0e08ce0c686bfa2c9d
Author: Jan Hubicka <jh@suse.cz>
Date:   Fri Mar 20 00:42:13 2020 +0100

    Fix cgraph_node::function_symbol availability compuattion [PR94202]
    
    this fixes ICE in inliner cache sanity check which is caused by very old
    bug in visibility calculation in cgraph_node::function_symbol and
    cgraph_node::function_or_virtual_thunk_symbol.
    
    In the testcase there is indirect call to a thunk. At begining we correctly
    see that its body as AVAIL_AVAILABLE but later we inline into the thunk and
    this turns it to AVAIL_INTERPOSABLE.
    
    This is because function_symbol incorrectly overwrites availability parameter
    by availability of the alias used in the call within thunk, which is a local
    alias.
    
    gcc/ChangeLog:
    
    2020-03-19  Jan Hubicka  <hubicka@ucw.cz>
    
            PR ipa/94202
            * cgraph.c (cgraph_node::function_symbol): Fix availability computation.
            (cgraph_node::function_or_virtual_thunk_symbol): Likewise.
    
    gcc/testsuite/ChangeLog:
    
    2020-03-19  Jan Hubicka  <hubicka@ucw.cz>
    
            PR ipa/94202
            * g++.dg/torture/pr94202.C: New test.

Diff:
---
 gcc/ChangeLog                          |  6 ++++++
 gcc/cgraph.c                           | 26 ++++++++++----------------
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/g++.dg/torture/pr94202.C | 22 ++++++++++++++++++++++
 4 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e1a778df202..44e320626a3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-03-19  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR ipa/94202
+	* cgraph.c (cgraph_node::function_symbol): Fix availability computation.
+	(cgraph_node::function_or_virtual_thunk_symbol): Likewise.
+
 2020-03-19  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR ipa/92372
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 9f0774f227f..b41dea1fcca 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -3788,16 +3788,13 @@ cgraph_node::function_symbol (enum availability *availability,
 
   while (node->thunk.thunk_p)
     {
+      enum availability a;
+
       ref = node;
       node = node->callees->callee;
-      if (availability)
-	{
-	  enum availability a;
-	  a = node->get_availability (ref);
-	  if (a < *availability)
-	    *availability = a;
-	}
-      node = node->ultimate_alias_target (availability, ref);
+      node = node->ultimate_alias_target (availability ? &a : NULL, ref);
+      if (availability && a < *availability)
+	*availability = a;
     }
   return node;
 }
@@ -3818,16 +3815,13 @@ cgraph_node::function_or_virtual_thunk_symbol
 
   while (node->thunk.thunk_p && !node->thunk.virtual_offset_p)
     {
+      enum availability a;
+
       ref = node;
       node = node->callees->callee;
-      if (availability)
-	{
-	  enum availability a;
-	  a = node->get_availability (ref);
-	  if (a < *availability)
-	    *availability = a;
-	}
-      node = node->ultimate_alias_target (availability, ref);
+      node = node->ultimate_alias_target (availability ? &a : NULL, ref);
+      if (availability && a < *availability)
+	*availability = a;
     }
   return node;
 }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index bde605d2b2f..212c6ffc06e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-19  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR ipa/94202
+	* g++.dg/torture/pr94202.C: New test.
+
 2020-03-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR gcov-profile/94029
diff --git a/gcc/testsuite/g++.dg/torture/pr94202.C b/gcc/testsuite/g++.dg/torture/pr94202.C
new file mode 100644
index 00000000000..5ed3dcbcd18
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr94202.C
@@ -0,0 +1,22 @@
+// { dg-additional-options "-w" }
+struct S1 {
+  virtual ~S1();
+  virtual void v();
+};
+struct S2: S1 {};
+struct S3: S1, S2 { void v(); };
+struct S4: S3 { void v(); };
+void S4::v() { S3::v(); }
+struct R {
+  S1 * m;
+  void f(S2 * x) {
+    static_cast<S1 *>(x)->v();
+    x->v();
+    m = x;
+  }
+};
+void f() {
+  R r;
+  r.f(new S4);
+  r.f(new S3);
+}