fix PR 17106

This fixes PR 17106, a regression in printing.

The bug is that resolve_dynamic_type follows struct members and
references, but doesn't consider the possibility of infinite
recursion.

This patch fixes the problem by limiting reference following to the
topmost layer of calls -- that is, reference-typed struct members are
never considered as being VLAs.

Built and regtested on x86-64 Fedora 20.
New test case included.

2014-07-14  Tom Tromey  <tromey@redhat.com>

	PR exp/17106:
	* gdbtypes.c (is_dynamic_type_internal): New function, from
	is_dynamic_type.
	(is_dynamic_type): Rewrite.
	(resolve_dynamic_union): Use resolve_dynamic_type_internal.
	(resolve_dynamic_struct): Likewise.
	(resolve_dynamic_type_internal): New function, from
	resolve_dynamic_type.
	(resolve_dynamic_type): Rewrite.

2014-07-14  Tom Tromey  <tromey@redhat.com>

	* gdb.cp/vla-cxx.cc: New file.
	* gdb.cp/vla-cxx.exp: New file.

3 files changed, 89 insertions, 0 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 71987a7..85deea5 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2014-07-14  Tom Tromey  <tromey@redhat.com>
 
+	* gdb.cp/vla-cxx.cc: New file.
+	* gdb.cp/vla-cxx.exp: New file.
+
+2014-07-14  Tom Tromey  <tromey@redhat.com>
+
 	* gdb.reverse/rerun-prec.c: New file.
 	* gdb.reverse/rerun-prec.exp: New file.
 
diff --git a/gdb/testsuite/gdb.cp/vla-cxx.cc b/gdb/testsuite/gdb.cp/vla-cxx.cc
new file mode 100644
index 0000000..ea75df2
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/vla-cxx.cc
@@ -0,0 +1,49 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2014 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+struct container;
+
+struct element
+{
+  container &c;
+
+  element(container &cc) : c (cc) { }
+};
+
+struct container
+{
+  element e;
+
+  container() : e(*this) { }
+};
+
+int main(int argc, char **argv)
+{
+  int z = 3;
+  // Note that this is a GNU extension.
+  int vla[z];
+  typeof (vla) &vlaref (vla);
+  typedef typeof (vla) &vlareftypedef;
+  vlareftypedef vlaref2 (vla);
+  container c;
+
+  for (int i = 0; i < z; ++i)
+    vla[i] = 5 + 2 * i;
+
+  // vlas_filled
+  return vla[2];
+}
diff --git a/gdb/testsuite/gdb.cp/vla-cxx.exp b/gdb/testsuite/gdb.cp/vla-cxx.exp
new file mode 100644
index 0000000..1ff815e
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/vla-cxx.exp
@@ -0,0 +1,35 @@
+# Copyright 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile .cc
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+    return -1
+}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint [gdb_get_line_number "vlas_filled"]
+gdb_continue_to_breakpoint "vlas_filled"
+
+gdb_test "print vla" " = \\{5, 7, 9\\}"
+gdb_test "print vlaref" " = \\(int \\(&\\)\\\[3\\\]\\) @$hex: \\{5, 7, 9\\}"
+# The ".*" here is because what gdb emits currently is "const
+# vlareftypedef", which seems incorrect -- and since that isn't the
+# bug being tested, it's better not to depend on the exact spelling.
+gdb_test "print vlaref2" " = \\(.*\\) @$hex: \\{5, 7, 9\\}"
+gdb_test "print c" " = \\{e = \\{c = @$hex\\}\\}"