[Bug plugins/98062] New: [11 regression] Crash in type_as_string from plugin

[Bug plugins/98062] New: [11 regression] Crash in type_as_string from plugin

[sss@li-snyder.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98062

            Bug ID: 98062
           Summary: [11 regression] Crash in type_as_string from plugin
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: plugins
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sss@li-snyder.org
  Target Milestone: ---

hi -

A plugin i'm working on crashes with gcc 11 because
pp_cxx_trait_expression doesn't handle the CPTK_IS_NOTHROW_CONSTRUCTIBLE enum.

Here's a simple reproducer.  First, here's the plugin:

-- p.cc ---------------------------------------------------
#include "gcc-plugin.h"
#include "cp/cp-tree.h"

int plugin_is_GPL_compatible;

void type_callback (void* gcc_data, void*)
{
  tree t = (tree)gcc_data;
  tree binfo = TYPE_BINFO (t);
  if (binfo && BINFO_N_BASE_BINFOS (binfo) > 0) {
    tree base_binfo = BINFO_BASE_BINFO (binfo, 0);
    tree bt = BINFO_TYPE (base_binfo);
    if (bt) {
      type_as_string (bt, 0);
    }
  }
}


extern "C" {

int
plugin_init(struct plugin_name_args   *, struct plugin_gcc_version *)
{
  register_callback ("a", PLUGIN_FINISH_TYPE, type_callback, nullptr);
  return 0;
}


} // extern "C"
-----------------------------------------------------------------------

Compile with

$ g++ -fPIC -shared -o libp.so  p.cc  -I`g++ -print-file-name=plugin`/include

Run it with this input:

-- x.cc ------------------------------------------------------------------
template <bool v> class B {};

template<typename _Tp>
struct is_nothrow_default_constructible
  : public B<__is_nothrow_constructible(_Tp)>
{
};
--------------------------------------------------------------------------

$ g++  -fplugin=libp.so   -c x.cc
*** WARNING *** there are active plugins, do not report this as a bug unless
you can reproduce it without enabling any plugins.
Event                            | Plugins
PLUGIN_FINISH_TYPE               | a
x.cc:7:1: internal compiler error: in pp_cxx_trait_expression, at
cp/cxx-pretty-print.c:2671
    7 | };
      | ^
0x61483f pp_cxx_trait_expression(cxx_pretty_printer*, tree_node*)
        /home/sss/gcc/gcc/gcc/cp/cxx-pretty-print.c:2671
0x6e82ef dump_template_parms
        /home/sss/gcc/gcc/gcc/cp/error.c:1945
0x6ec3dc type_as_string(tree_node*, int)
        /home/sss/gcc/gcc/gcc/cp/error.c:3024
0xbd60c9 invoke_plugin_callbacks_full(int, void*)
        /home/sss/gcc/gcc/gcc/plugin.c:588
0x73ed8f invoke_plugin_callbacks
        /home/sss/gcc/gcc/gcc/plugin.h:191
0x73ed8f cp_parser_type_specifier
        /home/sss/gcc/gcc/gcc/cp/parser.c:17964
0x73f7fb cp_parser_decl_specifier_seq
        /home/sss/gcc/gcc/gcc/cp/parser.c:14585
0x766536 cp_parser_single_declaration
        /home/sss/gcc/gcc/gcc/cp/parser.c:29908
0x766897 cp_parser_template_declaration_after_parameters
        /home/sss/gcc/gcc/gcc/cp/parser.c:29571
0x766e9a cp_parser_explicit_template_declaration
        /home/sss/gcc/gcc/gcc/cp/parser.c:29837
0x7697d9 cp_parser_declaration
        /home/sss/gcc/gcc/gcc/cp/parser.c:13609
0x76a04d cp_parser_translation_unit
        /home/sss/gcc/gcc/gcc/cp/parser.c:4806
0x76a04d c_parse_file()
        /home/sss/gcc/gcc/gcc/cp/parser.c:44630
0x837bed c_common_parse_file()
        /home/sss/gcc/gcc/gcc/c-family/c-opts.c:1198
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.


This patch fixes the crash:

diff --git a/gcc/cp/cxx-pretty-print.c b/gcc/cp/cxx-pretty-print.c
index 058b9c2f4fc..b1e10f9e2a8 100644
--- a/gcc/cp/cxx-pretty-print.c
+++ b/gcc/cp/cxx-pretty-print.c
@@ -2666,6 +2666,9 @@ pp_cxx_trait_expression (cxx_pretty_printer *pp, tree t)
     case CPTK_IS_CONSTRUCTIBLE:
       pp_cxx_ws_string (pp, "__is_constructible");
       break;
+    case CPTK_IS_NOTHROW_CONSTRUCTIBLE:
+      pp_cxx_ws_string (pp, "__is_nothrow_constructible");
+      break;

     default:
       gcc_unreachable ();


However, there are still a few other CPTK_ enums that aren't handled
in pp_cxx_trait_expression --- probably PTK_IS_NOTHROW_ASSIGNABLE
should be there, at least.

[Bug plugins/98062] [11 regression] Crash in type_as_string from plugin

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98062

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.0

[Bug c++/98062] [11 regression] Crash in type_as_string from plugin

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98062

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|plugins                     |c++

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Patches should be sent to gcc-patches@gcc.gnu.org

[Bug c++/98062] [11 regression] Crash in type_as_string from plugin

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98062

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
                 CC|                            |mpolacek at gcc dot gnu.org
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Most likely got resolved by r11-5629.