re PR ipa/83983 (FAIL: g++.dg/lto/pr83121 (test for LTO warnings, pr83121_0.C line 8))

	PR ipa/83983
	* ipa-devirt.c (odr_subtypes_equivalent_p): Get the ODR type of both
	arguments if they are comparable.

From-SVN: r258133

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4cadd4d2ca82a444b9c834c810b8df96518b51a7..4649ffa4fd9885ada6d48725067aa030167d47e6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-03-02  Eric Botcazou  <ebotcazou@adacore.com>
+
+       PR ipa/83983
+       * ipa-devirt.c (odr_subtypes_equivalent_p): Get the ODR type of both
+       arguments if they are comparable.
+
 2018-03-02  Richard Sandiford  <richard.sandiford@linaro.org>
 
        PR tree-optimization/84634

diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index f66dc45deb8668372b620d2348c39bef835f8c90..fae82072a7e90eb754bc96cca3684bbfdde20dac 100644 (file)
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -684,9 +684,14 @@ odr_subtypes_equivalent_p (tree t1, tree t2,
     {
       if (!types_same_for_odr (t1, t2, true))
         return false;
-      /* Limit recursion: If subtypes are ODR types and we know
-         that they are same, be happy.  */
-      if (!odr_type_p (t1) || !get_odr_type (t1, true)->odr_violated)
+      /* Limit recursion: if subtypes are ODR types and we know that they are
+        same, be happy.  We need to call get_odr_type on both subtypes since
+        we don't know which among t1 and t2 defines the common ODR type and
+        therefore which call will report the ODR violation, if any.  */
+        if (!odr_type_p (t1)
+            || !odr_type_p (t2)
+            || (!get_odr_type (t1, true)->odr_violated
+                && !get_odr_type (t2, true)->odr_violated))
         return true;
     }