Synchronize libiberty with gcc and add --no-recruse-limit option to tools that support name demangling.

This patch addresses the multitude of bug reports about resource exhaustion
in libiberty's name demangling code.  It adds a limit to the amount of
recursion that is allowed, before an error is triggered.  It also adds a
new demangling option to disable this limit.  (The limit is enabled by
default).

	PR 87681
	PR 87675
	PR 87636
	PR 87335
libiberty * cp-demangle.h (struct d_info): Add recursion_limit field.
	* cp-demangle.c (d_function_type): If the recursion limit is
	enabled and reached, return with a failure result.
        (d_demangle_callback): If the recursion limit is enabled, check
	for a mangled string that is so long that there is not enough
	stack space for the local arrays.
        * cplus-dem.c (struct work): Add recursion_level field.
	(demangle_nested_args): If the recursion limit is enabled and
	reached, return with a failure result.

include	* demangle.h (DMGL_RECURSE_LIMIT): Define.
        (DEMANGLE_RECURSION_LIMIT): Prototype.

binutuils * addr2line.c (demangle_flags): New static variable.
        (long_options): Add --recurse-limit and --no-recurse-limit.
        (translate_address): Pass demangle_flags to bfd_demangle.
        (main): Handle --recurse-limit and --no-recurse-limit options.
        * cxxfilt.c (flags): Add DMGL_RECURSE_LIMIT.
        (long_options): Add --recurse-limit and --no-recurse-limit.
        (main): Handle new options.
        * dlltool.c (gen_def_file): Include DMGL_RECURSE_LIMIT in flags
        passed to cplus_demangle.
        * nm.c (demangle_flags): New static variable.
        (long_options): Add --recurse-limit and --no-recurse-limit.
        (main): Handle new options.
        * objdump.c (demangle_flags): New static variable.
        (usage): Add --recurse-limit and --no-recurse-limit.
        (long_options): Likewise.
        (objdump_print_symname): Pass demangle_flags to bfd_demangle.
        (disassemble_section): Likewise.
        (dump_dymbols): Likewise.
        (main): Handle new options.
        * prdbg.c (demangle_flags): New static variable.
        (tg_variable): Pass demangle_flags to demangler.
        (tg_start_function): Likewise.
        * stabs.c (demangle_flags): New static variable.
        (stab_demangle_template): Pass demangle_flags to demangler.
        (stab_demangle_v3_argtypes): Likewise.
        (stab_demangle_v3_arg): Likewise.
	* doc/binutuls.texi: Document new command line options.
	* NEWS: Mention the new feature.
        * testsuite/config/default.exp (CXXFILT): Define if not already
        defined.
        (CXXFILTFLAGS): Likewise.
        * testsuite/binutils-all/cxxfilt.exp: New file.  Runs a few
        simple tests of the cxxfilt program.

2 files changed, 19 insertions, 0 deletions

diff --git a/include/ChangeLog b/include/ChangeLog
index 3b7c66d..69f7357 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,8 @@
+2018-12-07  Nick Clifton  <nickc@redhat.com>
+
+	* demangle.h (DMGL_NO_RECURSE_LIMIT): Define.
+        (DEMANGLE_RECURSION_LIMIT): Define
+
 2018-12-06  Alan Modra  <amodra@gmail.com>
 
 	* opcode/ppc.h (E_OPCODE_MASK, E_LI_MASK, E_LI_INSN): Define.
diff --git a/include/demangle.h b/include/demangle.h
index b8d57cf..1e67fe2 100644
--- a/include/demangle.h
+++ b/include/demangle.h
@@ -68,6 +68,17 @@ extern "C" {
 /* If none of these are set, use 'current_demangling_style' as the default. */
 #define DMGL_STYLE_MASK (DMGL_AUTO|DMGL_GNU|DMGL_LUCID|DMGL_ARM|DMGL_HP|DMGL_EDG|DMGL_GNU_V3|DMGL_JAVA|DMGL_GNAT|DMGL_DLANG|DMGL_RUST)
 
+/* Disable a limit on the depth of recursion in mangled strings.
+   Note if this limit is disabled then stack exhaustion is possible when
+   demangling pathologically complicated strings.  Bug reports about stack
+   exhaustion when the option is enabled will be rejected.  */  
+#define DMGL_NO_RECURSE_LIMIT (1 << 18)	
+
+/* If DMGL_NO_RECURSE_LIMIT is not enabled, then this is the value used as
+   the maximum depth of recursion allowed.  It should be enough for any
+   real-world mangled name.  */
+#define DEMANGLE_RECURSION_LIMIT 1024
+  
 /* Enumeration of possible demangling styles.
 
    Lucid and ARM styles are still kept logically distinct, even though
@@ -392,6 +403,9 @@ enum demangle_component_type
      template argument, and the right subtree is either NULL or
      another TEMPLATE_ARGLIST node.  */
   DEMANGLE_COMPONENT_TEMPLATE_ARGLIST,
+  /* A template parameter object (C++20).  The left subtree is the
+     corresponding template argument.  */
+  DEMANGLE_COMPONENT_TPARM_OBJ,
   /* An initializer list.  The left subtree is either an explicit type or
      NULL, and the right subtree is a DEMANGLE_COMPONENT_ARGLIST.  */
   DEMANGLE_COMPONENT_INITIALIZER_LIST,