[PATCH] Support bitfields in Wodr machinery (PR lto/85405).

[Martin Liška]

Hi.

This is Honza's ODR warning patch that I've just tested. He approved that.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Martin

gcc/ChangeLog:

2018-04-16  Jan Hubicka  <j...@suse.cz>

        PR lto/85405
        * ipa-devirt.c (odr_types_equivalent_p): Handle bit fields.

gcc/testsuite/ChangeLog:

2018-04-16  Martin Liska  <mli...@suse.cz>

        PR lto/85405
        * g++.dg/lto/pr85405_0.C: New test.
        * g++.dg/lto/pr85405_1.C: New test.
---
 gcc/ipa-devirt.c                     | 11 +++++++++--
 gcc/testsuite/g++.dg/lto/pr85405_0.C | 18 ++++++++++++++++++
 gcc/testsuite/g++.dg/lto/pr85405_1.C |  9 +++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/lto/pr85405_0.C
 create mode 100644 gcc/testsuite/g++.dg/lto/pr85405_1.C



diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index fa9380cce80..5da0f72d14f 100644
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -1587,8 +1587,15 @@ odr_types_equivalent_p (tree t1, tree t2, bool warn, bool *warned,
 				 "in another translation unit"));
 		    return false;
 		  }
-		gcc_assert (DECL_NONADDRESSABLE_P (f1)
-			    == DECL_NONADDRESSABLE_P (f2));
+		if (DECL_BIT_FIELD (f1) != DECL_BIT_FIELD (f2))
+		  {
+		    warn_odr (t1, t2, f1, f2, warn, warned,
+			      G_ ("one field is bitfield while other is not "));
+		    return false;
+		  }
+		else
+		  gcc_assert (DECL_NONADDRESSABLE_P (f1)
+			      == DECL_NONADDRESSABLE_P (f2));
 	      }
 
 	    /* If one aggregate has more fields than the other, they
diff --git a/gcc/testsuite/g++.dg/lto/pr85405_0.C b/gcc/testsuite/g++.dg/lto/pr85405_0.C
new file mode 100644
index 00000000000..1a41d81099c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/pr85405_0.C
@@ -0,0 +1,18 @@
+// { dg-lto-do link }
+// { dg-lto-options {{-fPIC -shared -flto}} }
+
+class VclReferenceBase { // { dg-lto-warning "7: type 'struct VclReferenceBase' violates the C\\+\\+ One Definition Rule" }
+  int mnRefCnt;
+  bool mbDisposed : 1;
+  virtual ~VclReferenceBase();
+};
+class a;
+class b {
+  a &e;
+  bool c();
+};
+class B {
+  VclReferenceBase d;
+};
+class a : B {};
+bool b::c() { return false; }
diff --git a/gcc/testsuite/g++.dg/lto/pr85405_1.C b/gcc/testsuite/g++.dg/lto/pr85405_1.C
new file mode 100644
index 00000000000..78606185624
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/pr85405_1.C
@@ -0,0 +1,9 @@
+class VclReferenceBase {
+  int mnRefCnt;
+  bool mbDisposed;
+
+protected:
+  virtual ~VclReferenceBase();
+};
+class : VclReferenceBase {
+} a;