libstdc++: [_GLIBCXX_DEBUG] Enhance rendering of assert message

Avoid building an intermediate buffer to print to stderr, push directly to stderr.

libstdc++-v3/ChangeLog:

	* include/debug/formatter.h
	(_Error_formatter::_Parameter::_Named): New.
	(_Error_formatter::_Parameter::_Type): Inherit latter.
	(_Error_formatter::_Parameter::_M_integer): Likewise.
	(_Error_formatter::_Parameter::_M_string): Likewise.
	* src/c++11/debug.cc: Include <cstring>.
	(_Print_func_t): New.
	(print_raw(PrintContext&, const char*, ptrdiff_t)): New.
	(print_word): Use '%.*s' format in fprintf to render only expected number of chars.
	(pretty_print(PrintContext&, const char*, _Print_func_t)): New.
	(print_type): Rename in...
	(print_type_info): ...this. Use pretty_print.
	(print_address, print_integer): New.
	(print_named_name, print_iterator_constness, print_iterator_state): New.
	(print_iterator_seq_type): New.
	(print_named_field, print_type_field, print_instance_field, print_iterator_field): New.
	(print_field): Use latters.
	(print_quoted_named_name, print_type_type, print_type, print_instance): New.
	(print_string(PrintContext&, const char*, const _Parameter*, size_t)):
	Change signature to...
	(print_string(PrintContext&, const char*, ptrdiff_t, const _Parameter*, size_t)):
	...this and adapt. Remove intermediate buffer to render input string.
	(print_string(PrintContext&, const char*, ptrdiff_t)): New.

diff --git a/libstdc++-v3/include/debug/formatter.h b/libstdc++-v3/include/debug/formatter.h
index 7140fed5e834327e773bb2811b6192d61adb0d14..a83d33a4cb86fc7c68c56897459489e91724dec7 100644 (file)
--- a/libstdc++-v3/include/debug/formatter.h
+++ b/libstdc++-v3/include/debug/formatter.h
@@ -202,9 +202,13 @@ namespace __gnu_debug
        __iterator_value_type
       } _M_kind;
 
-      struct _Type
+      struct _Named
       {
        const char*             _M_name;
+      };
+
+      struct _Type : _Named
+      {
        const type_info*        _M_type;
       };
 
@@ -228,16 +232,14 @@ namespace __gnu_debug
        _Instance _M_sequence;
 
        // When _M_kind == __integer
-       struct
+       struct : _Named
        {
-         const char*           _M_name;
          long                  _M_value;
        } _M_integer;
 
        // When _M_kind == __string
-       struct
+       struct : _Named
        {
-         const char*           _M_name;
          const char*           _M_value;
        } _M_string;
 

diff --git a/libstdc++-v3/src/c++11/debug.cc b/libstdc++-v3/src/c++11/debug.cc
index 5a642097d179cd1654a12ef5f907d3aae2cac960..33d76bfcaab879a42d8f6ba7c61f25795f5247b1 100644 (file)
--- a/libstdc++-v3/src/c++11/debug.cc
+++ b/libstdc++-v3/src/c++11/debug.cc
@@ -34,16 +34,12 @@
 
 #include <cassert>
 #include <cstdio>
-#include <cctype> // for std::isspace
+#include <cctype>      // for std::isspace.
+#include <cstring>     // for std::strstr.
 
-#include <algorithm> // for std::min
+#include <algorithm>   // for std::min.
 
-#include <cxxabi.h> // for __cxa_demangle
-
-// libstdc++/85768
-#if 0 // defined _GLIBCXX_HAVE_EXECINFO_H
-# include <execinfo.h> // for backtrace
-#endif
+#include <cxxabi.h>    // for __cxa_demangle.
 
 #include "mutex_pool.h"
 
@@ -574,7 +570,7 @@ namespace
   struct PrintContext
   {
     PrintContext()
-      : _M_max_length(78), _M_column(1), _M_first_line(true), _M_wordwrap(false)
+    : _M_max_length(78), _M_column(1), _M_first_line(true), _M_wordwrap(false)
     { get_max_length(_M_max_length); }
 
     std::size_t        _M_max_length;
@@ -584,16 +580,26 @@ namespace
     bool       _M_wordwrap;
   };
 
+  using _Print_func_t = void (PrintContext&, const char*, ptrdiff_t);
+
   template<size_t Length>
     void
     print_literal(PrintContext& ctx, const char(&word)[Length])
     { print_word(ctx, word, Length - 1); }
 
   void
-  print_word(PrintContext& ctx, const char* word,
-            std::ptrdiff_t count = -1)
+  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc = -1)
   {
-    size_t length = count >= 0 ? count : __builtin_strlen(word);
+    if (nbc >= 0)
+      ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
+    else
+      ctx._M_column += fprintf(stderr, "%s", str);
+  }
+
+  void
+  print_word(PrintContext& ctx, const char* word, ptrdiff_t nbc = -1)
+  {
+    size_t length = nbc >= 0 ? nbc : __builtin_strlen(word);
     if (length == 0)
       return;
 
@@ -610,7 +616,7 @@ namespace
       }
 
     size_t visual_length
-      = isspace(word[length - 1]) ? length - 1 : length;
+      = isspace((unsigned char)word[length - 1]) ? length - 1 : length;
     if (visual_length == 0
        || !ctx._M_wordwrap
        || (ctx._M_column + visual_length < ctx._M_max_length)
@@ -619,15 +625,11 @@ namespace
        // If this isn't the first line, indent
        if (ctx._M_column == 1 && !ctx._M_first_line)
          {
-           char spacing[ctx._M_indent + 1];
-           for (int i = 0; i < ctx._M_indent; ++i)
-             spacing[i] = ' ';
-           spacing[ctx._M_indent] = '\0';
-           fprintf(stderr, "%s", spacing);
-           ctx._M_column += ctx._M_indent;
+           const char spacing[ctx._M_indent + 1] = "    ";
+           print_raw(ctx, spacing, ctx._M_indent);
          }
 
-       int written = fprintf(stderr, "%s", word);
+       int written = fprintf(stderr, "%.*s", (int)length, word);
 
        if (word[length - 1] == '\n')
          {
@@ -640,15 +642,40 @@ namespace
     else
       {
        print_literal(ctx, "\n");
-       print_word(ctx, word, count);
+       print_word(ctx, word, nbc);
+      }
+  }
+
+  void
+  pretty_print(PrintContext& ctx, const char* str, _Print_func_t print_func)
+  {
+    const char cxx1998[] = "cxx1998::";
+    for (;;)
+      {
+       if (auto pos = strstr(str, "__"))
+         {
+           if (pos != str)
+             print_func(ctx, str, pos - str);
+
+           pos += 2; // advance past "__"
+           if (memcmp(pos, cxx1998, 9) == 0)
+             pos += 9; // advance part "cxx1998::"
+
+           str = pos;
+         }
+       else
+         {
+           print_func(ctx, str, -1);
+           break;
+         }
       }
   }
 
   template<size_t Length>
     void
-    print_type(PrintContext& ctx,
-              const type_info* info,
-              const char(&unknown_name)[Length])
+    print_type_info(PrintContext& ctx,
+                   const type_info* info,
+                   const char(&unknown_name)[Length])
     {
       if (!info)
        print_literal(ctx, unknown_name);
@@ -657,22 +684,86 @@ namespace
          int status;
          char* demangled_name =
            __cxxabiv1::__cxa_demangle(info->name(), NULL, NULL, &status);
-         print_word(ctx, status == 0 ? demangled_name : info->name());
+         if (status == 0)
+           pretty_print(ctx, demangled_name, &print_word);
+         else
+           print_word(ctx, info->name());
          free(demangled_name);
        }
     }
 
+  void
+  print_address(PrintContext& ctx, const char* fmt, const void* address)
+  {
+    char buf[128];
+    int written = __builtin_sprintf(buf, fmt, address);
+    print_word(ctx, buf, written);
+  }
+
+  void
+  print_address(PrintContext& ctx, const void* address)
+  { print_address(ctx, "%p", address); }
+
+  void
+  print_integer(PrintContext& ctx, long integer)
+  {
+    char buf[64];
+    int written = __builtin_sprintf(buf, "%ld", integer);
+    print_word(ctx, buf, written);
+  }
+
+  void
+  print_named_name(PrintContext& ctx, const _Parameter::_Named& named)
+  {
+    assert(named._M_name);
+    pretty_print(ctx, named._M_name, print_word);
+  }
+
+  template<typename _Iterator>
+    void
+    print_iterator_constness(PrintContext& ctx, const _Iterator& iterator)
+    {
+      static const char*
+       constness_names[_Error_formatter::__last_constness] =
+       {
+        "<unknown constness>",
+        "constant",
+        "mutable"
+       };
+      print_word(ctx, constness_names[iterator._M_constness]);
+    }
+
+  template<typename _Iterator>
+    void
+    print_iterator_state(PrintContext& ctx, const _Iterator& iterator)
+    {
+      static const char*
+       state_names[_Error_formatter::__last_state] =
+       {
+        "<unknown state>",
+        "singular",
+        "dereferenceable (start-of-sequence)",
+        "dereferenceable",
+        "past-the-end",
+        "before-begin",
+        "dereferenceable (start-of-reverse-sequence)",
+        "dereferenceable (reverse)",
+        "past-the-reverse-end"
+       };
+      print_word(ctx, state_names[iterator._M_state]);
+    }
+
+  template<typename _Iterator>
+    void
+    print_iterator_seq_type(PrintContext& ctx, const _Iterator& iterator)
+    { print_type_info(ctx, iterator._M_seq_type, "<unknown seq_type>"); }
+
   bool
-  print_field(PrintContext& ctx,
-             const char* name, const _Parameter::_Type& type)
+  print_named_field(PrintContext& ctx,
+                   const char* fname, const _Parameter::_Named& named)
   {
-    if (__builtin_strcmp(name, "name") == 0)
-      {
-       assert(type._M_name);
-       print_word(ctx, type._M_name);
-      }
-    else if (__builtin_strcmp(name, "type") == 0)
-      print_type(ctx, type._M_type, "<unknown type>");
+    if (__builtin_strcmp(fname, "name") == 0)
+      print_named_name(ctx, named);
     else
       return false;
 
@@ -680,112 +771,92 @@ namespace
   }
 
   bool
-  print_field(PrintContext& ctx,
-             const char* name, const _Parameter::_Instance& inst)
+  print_type_field(PrintContext& ctx,
+                  const char* fname, const _Parameter::_Type& type)
   {
-    const _Parameter::_Type& type = inst;
-    if (print_field(ctx, name, type))
+    if (print_named_field(ctx, fname, type))
       { }
-    else if (__builtin_strcmp(name, "address") == 0)
-      {
-       char buf[64];
-       int ret = __builtin_sprintf(buf, "%p", inst._M_address);
-       print_word(ctx, buf, ret);
-      }
+    else if (__builtin_strcmp(fname, "type") == 0)
+      print_type_info(ctx, type._M_type, "<unknown type>");
+    else
+      return false;
+
+    return true;
+  }
+
+  bool
+  print_instance_field(PrintContext& ctx,
+                      const char* fname, const _Parameter::_Instance& inst)
+  {
+    if (print_type_field(ctx, fname, inst))
+      { }
+    else if (__builtin_strcmp(fname, "address") == 0)
+      print_address(ctx, inst._M_address);
     else
       return false;
 
     return true;
   }
 
+  template<typename _Iterator>
+    bool
+    print_iterator_field(PrintContext& ctx,
+                        const char* fname, const _Iterator& iterator)
+    {
+      if (print_instance_field(ctx, fname, iterator))
+       { }
+      else if (__builtin_strcmp(fname, "constness") == 0)
+       print_iterator_constness(ctx, iterator);
+      else if (__builtin_strcmp(fname, "state") == 0)
+       print_iterator_state(ctx, iterator);
+      else if (__builtin_strcmp(fname, "sequence") == 0)
+       {
+         assert(iterator._M_sequence);
+         print_address(ctx, iterator._M_sequence);
+       }
+      else if (__builtin_strcmp(fname, "seq_type") == 0)
+       print_iterator_seq_type(ctx, iterator);
+      else
+       return false;
+
+      return true;
+    }
+
   void
-  print_field(PrintContext& ctx, const _Parameter& param, const char* name)
+  print_field(PrintContext& ctx, const _Parameter& param, const char* fname)
   {
     assert(param._M_kind != _Parameter::__unused_param);
-    const int bufsize = 64;
-    char buf[bufsize];
 
     const auto& variant = param._M_variant;
     switch (param._M_kind)
     {
     case _Parameter::__iterator:
-      {
-       const auto& iterator = variant._M_iterator;
-       if (print_field(ctx, name, iterator))
-         { }
-       else if (__builtin_strcmp(name, "constness") == 0)
-         {
-           static const char*
-             constness_names[_Error_formatter::__last_constness] =
-             {
-               "<unknown constness>",
-               "constant",
-               "mutable"
-             };
-           print_word(ctx, constness_names[iterator._M_constness]);
-         }
-       else if (__builtin_strcmp(name, "state") == 0)
-         {
-           static const char*
-             state_names[_Error_formatter::__last_state] =
-             {
-               "<unknown state>",
-               "singular",
-               "dereferenceable (start-of-sequence)",
-               "dereferenceable",
-               "past-the-end",
-               "before-begin",
-               "dereferenceable (start-of-reverse-sequence)",
-               "dereferenceable (reverse)",
-               "past-the-reverse-end"
-             };
-           print_word(ctx, state_names[iterator._M_state]);
-         }
-       else if (__builtin_strcmp(name, "sequence") == 0)
-         {
-           assert(iterator._M_sequence);
-           int written = __builtin_sprintf(buf, "%p", iterator._M_sequence);
-           print_word(ctx, buf, written);
-         }
-       else if (__builtin_strcmp(name, "seq_type") == 0)
-         print_type(ctx, iterator._M_seq_type, "<unknown seq_type>");
-       else
-         assert(false);
-      }
+      if (!print_iterator_field(ctx, fname, variant._M_iterator))
+       assert(false);
       break;
 
     case _Parameter::__sequence:
-      if (!print_field(ctx, name, variant._M_sequence))
+      if (!print_instance_field(ctx, fname, variant._M_sequence))
        assert(false);
       break;
 
     case _Parameter::__integer:
-      if (__builtin_strcmp(name, "name") == 0)
-       {
-         assert(variant._M_integer._M_name);
-         print_word(ctx, variant._M_integer._M_name);
-       }
-      else
+      if (!print_named_field(ctx, fname, variant._M_integer))
        assert(false);
       break;
 
     case _Parameter::__string:
-      if (__builtin_strcmp(name, "name") == 0)
-       {
-         assert(variant._M_string._M_name);
-         print_word(ctx, variant._M_string._M_name);
-       }
-      else
+      if (!print_named_field(ctx, fname, variant._M_string))
        assert(false);
       break;
 
     case _Parameter::__instance:
-      if (!print_field(ctx, name, variant._M_instance))
+      if (!print_instance_field(ctx, fname, variant._M_instance))
        assert(false);
       break;
 
     case _Parameter::__iterator_value_type:
-      if (!print_field(ctx, name, variant._M_iterator_value_type))
+      if (!print_type_field(ctx, fname, variant._M_iterator_value_type))
        assert(false);
       break;
 
@@ -796,55 +867,53 @@ namespace
   }
 
   void
-  print_description(PrintContext& ctx, const _Parameter::_Type& type)
+  print_quoted_named_name(PrintContext& ctx, const _Parameter::_Named& named)
   {
-    if (type._M_name)
+    if (named._M_name)
       {
        print_literal(ctx, "\"");
-       print_word(ctx, type._M_name);
-       print_literal(ctx, "\"");
+       print_named_name(ctx, named);
+       print_literal(ctx, "\" ");
       }
+  }
 
-    print_literal(ctx, " {\n");
-
+  void
+  print_type_type(PrintContext& ctx, const _Parameter::_Type& type,
+                 bool close_desc = true)
+  {
     if (type._M_type)
       {
        print_literal(ctx, "  type = ");
-       print_type(ctx, type._M_type, "<unknown type>");
-       print_literal(ctx, ";\n");
+       print_type_info(ctx, type._M_type, "<unknown type>");
+       if (close_desc)
+         print_literal(ctx, ";\n");
       }
   }
 
   void
-  print_description(PrintContext& ctx, const _Parameter::_Instance& inst)
+  print_type(PrintContext& ctx, const _Parameter::_Type& type)
   {
-    const int bufsize = 64;
-    char buf[bufsize];
-
-    if (inst._M_name)
-      {
-       print_literal(ctx, "\"");
-       print_word(ctx, inst._M_name);
-       print_literal(ctx, "\" ");
-      }
+    print_quoted_named_name(ctx, type);
+    print_literal(ctx, " {\n");
+    print_type_type(ctx, type);
+    print_literal(ctx, "}\n");
+  }
 
-    int written
-      = __builtin_sprintf(buf, "@ 0x%p {\n", inst._M_address);
-    print_word(ctx, buf, written);
+  void
+  print_instance(PrintContext& ctx, const _Parameter::_Instance& inst,
+                bool close_desc = true)
+  {
+    print_quoted_named_name(ctx, inst);
+    print_address(ctx, "@ %p {\n", inst._M_address);
+    print_type_type(ctx, inst, close_desc);
 
-    if (inst._M_type)
-      {
-       print_literal(ctx, "  type = ");
-       print_type(ctx, inst._M_type, "<unknown type>");
-      }
+    if (close_desc)
+      print_literal(ctx, "}\n");
   }
 
   void
   print_description(PrintContext& ctx, const _Parameter& param)
   {
-    const int bufsize = 128;
-    char buf[bufsize];
-
     const auto& variant = param._M_variant;
     switch (param._M_kind)
       {
@@ -853,14 +922,14 @@ namespace
          const auto& ite = variant._M_iterator;
 
          print_literal(ctx, "iterator ");
-         print_description(ctx, ite);
+         print_instance(ctx, ite, false);
 
          if (ite._M_type)
            {
              if (ite._M_constness != _Error_formatter::__unknown_constness)
                {
                  print_literal(ctx, " (");
-                 print_field(ctx, param, "constness");
+                 print_iterator_constness(ctx, ite);
                  print_literal(ctx, " iterator)");
                }
 
@@ -870,7 +939,7 @@ namespace
          if (ite._M_state != _Error_formatter::__unknown_state)
            {
              print_literal(ctx, "  state = ");
-             print_field(ctx, param, "state");
+             print_iterator_state(ctx, ite);
              print_literal(ctx, ";\n");
            }
 
@@ -880,13 +949,11 @@ namespace
              if (ite._M_seq_type)
                {
                  print_literal(ctx, "with type '");
-                 print_field(ctx, param, "seq_type");
+                 print_iterator_seq_type(ctx, ite);
                  print_literal(ctx, "' ");
                }
 
-             int written
-               = __builtin_sprintf(buf, "@ 0x%p\n", ite._M_sequence);
-             print_word(ctx, buf, written);
+             print_address(ctx, "@ %p\n", ite._M_sequence);
            }
 
          print_literal(ctx, "}\n");
@@ -895,28 +962,17 @@ namespace
 
       case _Parameter::__sequence:
        print_literal(ctx, "sequence ");
-       print_description(ctx, variant._M_sequence);
-
-       if (variant._M_sequence._M_type)
-         print_literal(ctx, ";\n");
-
-       print_literal(ctx, "}\n");
+       print_instance(ctx, variant._M_sequence);
        break;
 
       case _Parameter::__instance:
        print_literal(ctx, "instance ");
-       print_description(ctx, variant._M_instance);
-
-       if (variant._M_instance._M_type)
-         print_literal(ctx, ";\n");
-
-       print_literal(ctx, "}\n");
+       print_instance(ctx, variant._M_instance);
        break;
 
       case _Parameter::__iterator_value_type:
        print_literal(ctx, "iterator::value_type ");
-       print_description(ctx, variant._M_iterator_value_type);
-       print_literal(ctx, "}\n");
+       print_type(ctx, variant._M_iterator_value_type);
        break;
 
       default:
@@ -925,71 +981,67 @@ namespace
   }
 
   void
-  print_string(PrintContext& ctx, const char* string,
+  print_string(PrintContext& ctx, const char* str, ptrdiff_t nbc,
               const _Parameter* parameters, std::size_t num_parameters)
   {
-    const char* start = string;
-    const int bufsize = 128;
-    char buf[bufsize];
-    int bufindex = 0;
+    const char* start = str;
+    const char* end = nbc >= 0 ? start + nbc : nullptr;
 
-    while (*start)
+    while ((end && str != end) || (!end && *str))
       {
-       if (isspace(*start))
+       if (isspace((unsigned char)*str))
          {
-           buf[bufindex++] = *start++;
-           buf[bufindex] = '\0';
-           print_word(ctx, buf, bufindex);
-           bufindex = 0;
+           ++str;
+           print_word(ctx, start, str - start);
+           start = str;
            continue;
          }
 
-       if (!num_parameters || *start != '%')
+       if (!parameters || *str != '%')
          {
            // Normal char or no parameter to look for.
-           buf[bufindex++] = *start++;
+           ++str;
            continue;
          }
 
-       if (*++start == '%')
+       if (*++str == '%')
          {
            // Escaped '%'
-           buf[bufindex++] = *start++;
+           print_word(ctx, start, str - start);
+           ++str;
+           start = str;
            continue;
          }
 
        // We are on a parameter property reference, we need to flush buffer
        // first.
-       if (bufindex != 0)
+       if (str != start)
          {
-           buf[bufindex] = '\0';
-           print_word(ctx, buf, bufindex);
-           bufindex = 0;
+           // Avoid printing the '%'.
+           if (str - start > 1)
+             print_word(ctx, start, str - start - 1);
+           start = str;
          }
 
        // Get the parameter number
-       assert(*start >= '1' && *start <= '9');
-       size_t param_index = *start - '0' - 1;
+       assert(*str >= '1' && *str <= '9');
+       size_t param_index = *str - '0' - 1;
        assert(param_index < num_parameters);
        const auto& param = parameters[param_index];
 
        // '.' separates the parameter number from the field
        // name, if there is one.
-       ++start;
-       if (*start != '.')
+       ++str;
+       if (*str != '.')
          {
-           assert(*start == ';');
-           ++start;
+           assert(*str == ';');
+           ++str;
            if (param._M_kind == _Parameter::__integer)
-             {
-               int written
-                 = __builtin_sprintf(buf, "%ld",
-                                     param._M_variant._M_integer._M_value);
-               print_word(ctx, buf, written);
-             }
+             print_integer(ctx, param._M_variant._M_integer._M_value);
            else if (param._M_kind == _Parameter::__string)
-             print_string(ctx, param._M_variant._M_string._M_value,
+             print_string(ctx, param._M_variant._M_string._M_value, -1,
                           parameters, num_parameters);
+           start = str;
            continue;
          }
 
@@ -997,26 +1049,28 @@ namespace
        const int max_field_len = 16;
        char field[max_field_len];
        int field_idx = 0;
-       ++start;
-       while (*start != ';')
+       ++str;
+       while (*str != ';')
          {
-           assert(*start);
+           assert(*str);
            assert(field_idx < max_field_len - 1);
-           field[field_idx++] = *start++;
+           field[field_idx++] = *str++;
          }
-       ++start;
+       ++str;
        field[field_idx] = '\0';
 
        print_field(ctx, param, field);
+       start = str;
       }
 
     // Might need to flush.
-    if (bufindex)
-      {
-       buf[bufindex] = '\0';
-       print_word(ctx, buf, bufindex);
-      }
+    if (str != start)
+      print_word(ctx, start, str - start);
   }
+
+  void
+  print_string(PrintContext& ctx, const char* str, ptrdiff_t nbc)
+  { print_string(ctx, str, nbc, nullptr, 0); }
 }
 
 namespace __gnu_debug
@@ -1036,16 +1090,15 @@ namespace __gnu_debug
     PrintContext ctx;
     if (_M_file)
       {
-       print_word(ctx, _M_file);
+       print_raw(ctx, _M_file);
        print_literal(ctx, ":");
        go_to_next_line = true;
       }
 
     if (_M_line > 0)
       {
-       char buf[64];
-       int written = __builtin_sprintf(buf, "%u:", _M_line);
-       print_word(ctx, buf, written);
+       ctx._M_column += fprintf(stderr, "%u", _M_line);
+       print_literal(ctx, ":");
        go_to_next_line = true;
       }
 
@@ -1058,41 +1111,17 @@ namespace __gnu_debug
     if (_M_function)
       {
        print_literal(ctx, "In function:\n");
-       print_string(ctx, _M_function, nullptr, 0);
+       pretty_print(ctx, _M_function, &print_string);
        print_literal(ctx, "\n");
        ctx._M_first_line = true;
        print_literal(ctx, "\n");
       }
 
-// libstdc++/85768
-#if 0 //defined _GLIBCXX_HAVE_EXECINFO_H
-    {
-      void* stack[32];
-      int nb = backtrace(stack, 32);
-
-      // Note that we skip current method symbol.
-      if (nb > 1)
-       {
-         print_literal(ctx, "Backtrace:\n");
-         auto symbols = backtrace_symbols(stack, nb);
-         for (int i = 1; i < nb; ++i)
-           {
-             print_word(ctx, symbols[i]);
-             print_literal(ctx, "\n");
-           }
-
-         free(symbols);
-         ctx._M_first_line = true;
-         print_literal(ctx, "\n");
-       }
-    }
-#endif
-
     print_literal(ctx, "Error: ");
 
     // Print the error message
     assert(_M_text);
-    print_string(ctx, _M_text, _M_parameters, _M_num_parameters);
+    print_string(ctx, _M_text, -1, _M_parameters, _M_num_parameters);
     print_literal(ctx, ".\n");
 
     // Emit descriptions of the objects involved in the operation