Hi,
in this error recovery issue, after a sensible error message about
duplicate base type and a redundant one about an incomplete type (the
type with the erroneous base type) we finally crash much later in
build_simple_base_path. Yesterday I noticed that elsewhere we don't
check the return value of xref_basetypes (which only returns false after
an hard error) and error recovery seems better if we don't zero the type
in such cases (we don't end up with this weird half-erroneous,
half-incomplete type declaration which we have to tell from the good
ones downstream, we have instead an usable reference for the informs
about duplicated definitions (see yesterday's patch), etc.). I also
found the commit which introduced the zeroing, r189582, back in 2012,
and the testcase which was crashing back then is now correctly handled
anyway. Thus, all in all, I'm proposing the below for trunk. I guess we
can quickly back it out if we realize that error recovery gets much
worse in other as yet unknown situations.
Tested x86_64-linux.
Thanks,
Paolo.
/////////////////////////////
/cp
2016-06-03 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/70202
* parser.c (cp_parser_class_head): When xref_basetypes fails and
emits an error do not zero the type.
/testsuite
2016-06-03 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/70202
* g++.dg/inherit/crash5.C: New.
* g++.dg/inherit/virtual1.C: Adjust.
Index: cp/parser.c
===================================================================
--- cp/parser.c (revision 237046)
+++ cp/parser.c (working copy)
@@ -22050,9 +22050,8 @@ cp_parser_class_head (cp_parser* parser,
/* If we're really defining a class, process the base classes.
If they're invalid, fail. */
- if (type && cp_lexer_next_token_is (parser->lexer, CPP_OPEN_BRACE)
- && !xref_basetypes (type, bases))
- type = NULL_TREE;
+ if (type && cp_lexer_next_token_is (parser->lexer, CPP_OPEN_BRACE))
+ xref_basetypes (type, bases);
done:
/* Leave the scope given by the nested-name-specifier. We will
Index: testsuite/g++.dg/inherit/crash5.C
===================================================================
--- testsuite/g++.dg/inherit/crash5.C (revision 0)
+++ testsuite/g++.dg/inherit/crash5.C (working copy)
@@ -0,0 +1,10 @@
+// PR c++/70202
+
+class A
+{
+ virtual void foo () { }
+};
+class B : public A, A { }; // { dg-error "duplicate base type" }
+
+B b1, &b2 = b1;
+A a = b2;
Index: testsuite/g++.dg/inherit/virtual1.C
===================================================================
--- testsuite/g++.dg/inherit/virtual1.C (revision 237045)
+++ testsuite/g++.dg/inherit/virtual1.C (working copy)
@@ -5,8 +5,8 @@ struct A
virtual ~A() {}
};
-struct B : A, virtual A {}; // { dg-error "duplicate base|forward
declaration" }
+struct B : A, virtual A {}; // { dg-error "duplicate base" }
-struct C : A, B {}; // { dg-error "duplicate base|invalid use" }
+struct C : A, B {}; // { dg-error "duplicate base" }
-C c; // { dg-error "aggregate" }
+C c;
