diff mbox

[C++] PR 69637

Message ID 3eec85dc-878a-4bb5-6a19-8efe7a0aaa78@oracle.com
State New
Headers show

Commit Message

Paolo Carlini Feb. 1, 2017, 1:24 p.m. UTC 
Hi,

I'm still working on a number of ICEs on invalid happening during error 
recovery...

In these cases, after a meaningful diagnostic, we ICE in 
cxx_eval_constant_expression because it doesn't handle OVERLOADs and 
TEMPLATE_ID_EXPRs in the main switch. I tried a number of different 
approaches, but I think the most straightforward one is the below: avoid 
setting up  in grokbitfield DECL_INITIAL (and SET_DECL_C_BIT_FIELD) 
after the early diagnostic, exactly as currently happens when the width 
passed to the function is an error_mark_node. In particular, the 
approach seems robust because the callers don't use the the width 
information afterward (it's only passed to grokbitfield). Tested 
x86_64-linux.

Thanks, Paolo.

///////////////////
/cp
2017-02-01  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/69637
	* decl2.c (grokbitfield): In case of error don't set-up DECL_INITIAL
	to the width.

/testsuite
2017-02-01  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/69637
	* g++.dg/cpp0x/pr69637-1.C: New.
	* g++.dg/cpp0x/pr69637-2.C: Likewise.

Comments

Nathan Sidwell Feb. 1, 2017, 3:13 p.m. UTC | #1 
On 02/01/2017 08:24 AM, Paolo Carlini wrote:
> Hi,
>
> I'm still working on a number of ICEs on invalid happening during error
> recovery...
>
> In these cases, after a meaningful diagnostic, we ICE in
> cxx_eval_constant_expression because it doesn't handle OVERLOADs and
> TEMPLATE_ID_EXPRs in the main switch. I tried a number of different
> approaches, but I think the most straightforward one is the below: avoid
> setting up  in grokbitfield DECL_INITIAL (and SET_DECL_C_BIT_FIELD)
> after the early diagnostic, exactly as currently happens when the width
> passed to the function is an error_mark_node. In particular, the
> approach seems robust because the callers don't use the the width
> information afterward (it's only passed to grokbitfield). Tested
> x86_64-linux.


ok, thanks
diff mbox

Patch

Index: cp/decl2.c
===================================================================
--- cp/decl2.c	(revision 245084)
+++ cp/decl2.c	(working copy)
@@ -1059,8 +1059,11 @@  grokbitfield (const cp_declarator *declarator,
 	  && !INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (width)))
 	error ("width of bit-field %qD has non-integral type %qT", value,
 	       TREE_TYPE (width));
-      DECL_INITIAL (value) = width;
-      SET_DECL_C_BIT_FIELD (value);
+      else
+	{
+	  DECL_INITIAL (value) = width;
+	  SET_DECL_C_BIT_FIELD (value);
+	}
     }
 
   DECL_IN_AGGR_P (value) = 1;
Index: testsuite/g++.dg/cpp0x/pr69637-1.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr69637-1.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/pr69637-1.C	(working copy)
@@ -0,0 +1,8 @@ 
+// { dg-do compile { target c++11 } }
+
+template <class T>
+int foo () { return 1; }
+
+struct B {
+    unsigned c: foo;  // { dg-error "non-integral type" }
+};
Index: testsuite/g++.dg/cpp0x/pr69637-2.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr69637-2.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/pr69637-2.C	(working copy)
@@ -0,0 +1,6 @@ 
+// { dg-do compile { target c++11 } }
+
+template <class T, int N>
+constexpr int foo () { return N; }
+
+struct B { unsigned c: foo<int>, 3(); };  // { dg-error "non-integral type|expected" }