We were ICEing on the attached testcase, because in check_narrowing,
for = {{}}, we wanted to check recursively the CONSTRUCTOR_ELTs,
even though init in this case has 0 CONSTRUCTOR_NELTS. So I added
the check for CONSTRUCTOR_NELTS > 0. Moreover, since empty scalar
initializers are forbidden in C FE, I think we should error out here
too. (Complex type is considered as an arithmetic type as a GNU
extension and arithmetic types are scalar types.)
This isn't C++11-specific as it may look from the PR. The bug
exhibits when -Wnarrowing (that is implicitly enabled with C++11) is
on, since in check_narrowing we have
if (!warn_narrowing || !ARITHMETIC_TYPE_P (type))
return;
and with -Wno-narrowing we just return early.
Regtested/bootstrapped on x86_64-linux, ok for trunk?
2013-10-14 Marek Polacek <pola...@redhat.com>
PR c++/58705
cp/
* typeck2.c (check_narrowing): Give an error when the scalar
initializer is empty.
testsuite/
* g++.dg/parse/pr58705.C: New test.
--- gcc/cp/typeck2.c.mp 2013-10-14 11:11:36.971293089 +0200
+++ gcc/cp/typeck2.c 2013-10-14 11:52:14.582061052 +0200
@@ -833,7 +833,10 @@ check_narrowing (tree type, tree init)
&& TREE_CODE (type) == COMPLEX_TYPE)
{
tree elttype = TREE_TYPE (type);
- check_narrowing (elttype, CONSTRUCTOR_ELT (init, 0)->value);
+ if (CONSTRUCTOR_NELTS (init) > 0)
+ check_narrowing (elttype, CONSTRUCTOR_ELT (init, 0)->value);
+ else
+ error ("empty scalar initializer");
if (CONSTRUCTOR_NELTS (init) > 1)
check_narrowing (elttype, CONSTRUCTOR_ELT (init, 1)->value);
return;
--- gcc/testsuite/g++.dg/parse/pr58705.C.mp 2013-10-14 11:14:46.460955343
+0200
+++ gcc/testsuite/g++.dg/parse/pr58705.C 2013-10-14 11:51:02.698810118
+0200
@@ -0,0 +1,5 @@
+// PR c++/58705
+// { dg-do compile }
+// { dg-options "-Wnarrowing" }
+
+_Complex float f = {{}}; // { dg-error "empty scalar initializer" }
Marek
