Don't derive partial_symbol from general_symbol_info

This patch partly reverts commit 8a6d42345 ("Change representation of
psymbol to flush out accessors"); specifically, it changes
partial_symbol to no longer derive from general_symbol_info.

The basic problem here is that the bcache compares objects bitwise,
and this change made it less likely that the relevant fields in the
psymbol would be fully initialized.  This could be seen by running a
test under valgrind on the Fedora-i686 buildbot.

I considered a simpler patch, namely just zeroing the psymbol's
"value" field in add_psymbol_to_bcache.  However, it wasn't clear to
me that this memset could not then be optimized away by the compiler.

Regression tested by the buildbot.  I think this should go in 8.3 as
well.

2019-05-04  Tom Tromey  <tom@tromey.com>

	* psymtab.c (psymbol_name_matches, match_partial_symbol)
	(lookup_partial_symbol, print_partial_symbols)
	(recursively_search_psymtabs, sort_pst_symbols, psymbol_hash)
	(psymbol_compare): Update.
	(add_psymbol_to_bcache): Clear the entire psymbol.
	(maintenance_check_psymtabs): Update.
	* psympriv.h (struct partial_symbol): Don't derive from
	general_symbol_info.
	<obj_section, unrelocated_address, address,
	set_unrelocated_address>: Update.
	<ginfo>: New member.
	* dwarf-index-write.c (write_psymbols, debug_names::insert)
	(debug_names::write_psymbols): Update.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index eb56ca0fb60e76230c1bb643606cdfc3467b6024..ebd6a5251cdc874ba73ef8b0ea217ad3a6a7c0ae 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,19 @@
+2019-05-04  Tom Tromey  <tom@tromey.com>
+
+       * psymtab.c (psymbol_name_matches, match_partial_symbol)
+       (lookup_partial_symbol, print_partial_symbols)
+       (recursively_search_psymtabs, sort_pst_symbols, psymbol_hash)
+       (psymbol_compare): Update.
+       (add_psymbol_to_bcache): Clear the entire psymbol.
+       (maintenance_check_psymtabs): Update.
+       * psympriv.h (struct partial_symbol): Don't derive from
+       general_symbol_info.
+       <obj_section, unrelocated_address, address,
+       set_unrelocated_address>: Update.
+       <ginfo>: New member.
+       * dwarf-index-write.c (write_psymbols, debug_names::insert)
+       (debug_names::write_psymbols): Update.
+
 2019-05-03  Eli Zaretskii  <eliz@gnu.org>
 
        * windows-nat.c [_WIN32_WINNT]: Define _WIN32_WINNT to Windows XP

diff --git a/gdb/dwarf-index-write.c b/gdb/dwarf-index-write.c
index 01c1256bcb63ef81a5341ec6a13bf2d8a97cb648..519179be4d837d9bf476267bca5e17ad417d2a17 100644 (file)
--- a/gdb/dwarf-index-write.c
+++ b/gdb/dwarf-index-write.c
@@ -540,7 +540,7 @@ write_psymbols (struct mapped_symtab *symtab,
     {
       struct partial_symbol *psym = *psymp;
 
-      if (psym->language == language_ada)
+      if (psym->ginfo.language == language_ada)
        error (_("Ada is not currently supported by the index"));
 
       /* Only add a given psymbol once.  */
@@ -548,7 +548,7 @@ write_psymbols (struct mapped_symtab *symtab,
        {
          gdb_index_symbol_kind kind = symbol_kind (psym);
 
-         add_index_entry (symtab, symbol_search_name (psym),
+         add_index_entry (symtab, symbol_search_name (&psym->ginfo),
                           is_static, kind, cu_index);
        }
     }
@@ -684,7 +684,7 @@ public:
     const int dwarf_tag = psymbol_tag (psym);
     if (dwarf_tag == 0)
       return;
-    const char *const name = symbol_search_name (psym);
+    const char *const name = symbol_search_name (&psym->ginfo);
     const auto insertpair
       = m_name_to_value_set.emplace (c_str_view (name),
                                     std::set<symbol_value> ());
@@ -1181,7 +1181,7 @@ private:
       {
        struct partial_symbol *psym = *psymp;
 
-       if (psym->language == language_ada)
+       if (psym->ginfo.language == language_ada)
          error (_("Ada is not currently supported by the index"));
 
        /* Only add a given psymbol once.  */

diff --git a/gdb/psympriv.h b/gdb/psympriv.h
index 7d2ce30f2e69ff470c60490e8dc6200019cbf60c..61d73a316b8e107b19edd29461fc4d69eb8bb2e1 100644 (file)
--- a/gdb/psympriv.h
+++ b/gdb/psympriv.h
@@ -33,37 +33,43 @@
 /* This structure is space critical.  See space comments at the top of
    symtab.h.  */
 
-struct partial_symbol : public general_symbol_info
+struct partial_symbol
 {
   /* Return the section for this partial symbol, or nullptr if no
      section has been set.  */
   struct obj_section *obj_section (struct objfile *objfile) const
   {
-    if (section >= 0)
-      return &objfile->sections[section];
+    if (ginfo.section >= 0)
+      return &objfile->sections[ginfo.section];
     return nullptr;
   }
 
   /* Return the unrelocated address of this partial symbol.  */
   CORE_ADDR unrelocated_address () const
   {
-    return value.address;
+    return ginfo.value.address;
   }
 
   /* Return the address of this partial symbol, relocated according to
      the offsets provided in OBJFILE.  */
   CORE_ADDR address (const struct objfile *objfile) const
   {
-    return value.address + ANOFFSET (objfile->section_offsets, section);
+    return (ginfo.value.address
+           + ANOFFSET (objfile->section_offsets, ginfo.section));
   }
 
   /* Set the address of this partial symbol.  The address must be
      unrelocated.  */
   void set_unrelocated_address (CORE_ADDR addr)
   {
-    value.address = addr;
+    ginfo.value.address = addr;
   }
 
+  /* Note that partial_symbol does not derive from general_symbol_info
+     due to the bcache.  See add_psymbol_to_bcache.  */
+
+  struct general_symbol_info ginfo;
+
   /* Name space code.  */
 
   ENUM_BITFIELD(domain_enum_tag) domain : SYMBOL_DOMAIN_BITS;

diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 17db29759c4ca8be592696c23838935a1d9ff6a8..0a4502e4f59398c3c23dee8a2b2ea51c93ae45fe 100644 (file)
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -532,10 +532,10 @@ static bool
 psymbol_name_matches (partial_symbol *psym,
                      const lookup_name_info &lookup_name)
 {
-  const language_defn *lang = language_def (psym->language);
+  const language_defn *lang = language_def (psym->ginfo.language);
   symbol_name_matcher_ftype *name_match
     = get_symbol_name_matcher (lang, lookup_name);
-  return name_match (symbol_search_name (psym), lookup_name, NULL);
+  return name_match (symbol_search_name (&psym->ginfo), lookup_name, NULL);
 }
 
 /* Look in PST for a symbol in DOMAIN whose name matches NAME.  Search
@@ -585,11 +585,12 @@ match_partial_symbol (struct objfile *objfile,
          center = bottom + (top - bottom) / 2;
          gdb_assert (center < top);
 
-         enum language lang = (*center)->language;
+         enum language lang = (*center)->ginfo.language;
          const char *lang_ln
            = lookup_name.language_lookup_name (lang).c_str ();
 
-         if (ordered_compare (symbol_search_name (*center), lang_ln) >= 0)
+         if (ordered_compare (symbol_search_name (&(*center)->ginfo),
+                              lang_ln) >= 0)
            top = center;
          else
            bottom = center + 1;
@@ -599,7 +600,7 @@ match_partial_symbol (struct objfile *objfile,
       while (top <= real_top
             && psymbol_name_matches (*top, lookup_name))
        {
-         if (symbol_matches_domain ((*top)->language,
+         if (symbol_matches_domain ((*top)->ginfo.language,
                                     (*top)->domain, domain))
            return *top;
          top++;
@@ -613,7 +614,7 @@ match_partial_symbol (struct objfile *objfile,
     {
       for (psym = start; psym < start + length; psym++)
        {
-         if (symbol_matches_domain ((*psym)->language,
+         if (symbol_matches_domain ((*psym)->ginfo.language,
                                     (*psym)->domain, domain)
              && psymbol_name_matches (*psym, lookup_name))
            return *psym;
@@ -696,7 +697,7 @@ lookup_partial_symbol (struct objfile *objfile,
          if (!(center < top))
            internal_error (__FILE__, __LINE__,
                            _("failed internal consistency check"));
-         if (strcmp_iw_ordered (symbol_search_name (*center),
+         if (strcmp_iw_ordered (symbol_search_name (&(*center)->ginfo),
                                 search_name.get ()) >= 0)
            {
              top = center;
@@ -712,15 +713,17 @@ lookup_partial_symbol (struct objfile *objfile,
 
       /* For `case_sensitivity == case_sensitive_off' strcmp_iw_ordered will
         search more exactly than what matches SYMBOL_MATCHES_SEARCH_NAME.  */
-      while (top >= start && symbol_matches_search_name (*top, lookup_name))
+      while (top >= start && symbol_matches_search_name (&(*top)->ginfo,
+                                                        lookup_name))
        top--;
 
       /* Fixup to have a symbol which matches SYMBOL_MATCHES_SEARCH_NAME.  */
       top++;
 
-      while (top <= real_top && symbol_matches_search_name (*top, lookup_name))
+      while (top <= real_top && symbol_matches_search_name (&(*top)->ginfo,
+                                                           lookup_name))
        {
-         if (symbol_matches_domain ((*top)->language,
+         if (symbol_matches_domain ((*top)->ginfo.language,
                                     (*top)->domain, domain))
            return *top;
          top++;
@@ -734,9 +737,9 @@ lookup_partial_symbol (struct objfile *objfile,
     {
       for (psym = start; psym < start + length; psym++)
        {
-         if (symbol_matches_domain ((*psym)->language,
+         if (symbol_matches_domain ((*psym)->ginfo.language,
                                     (*psym)->domain, domain)
-             && symbol_matches_search_name (*psym, lookup_name))
+             && symbol_matches_search_name (&(*psym)->ginfo, lookup_name))
            return *psym;
        }
     }
@@ -836,10 +839,11 @@ print_partial_symbols (struct gdbarch *gdbarch, struct objfile *objfile,
   while (count-- > 0)
     {
       QUIT;
-      fprintf_filtered (outfile, "    `%s'", (*p)->name);
-      if (symbol_demangled_name (*p) != NULL)
+      fprintf_filtered (outfile, "    `%s'", (*p)->ginfo.name);
+      if (symbol_demangled_name (&(*p)->ginfo) != NULL)
        {
-         fprintf_filtered (outfile, "  `%s'", symbol_demangled_name (*p));
+         fprintf_filtered (outfile, "  `%s'",
+                           symbol_demangled_name (&(*p)->ginfo));
        }
       fputs_filtered (", ", outfile);
       switch ((*p)->domain)
@@ -1309,7 +1313,8 @@ recursively_search_psymtabs
               || (domain == TYPES_DOMAIN
                   && (*psym)->aclass == LOC_TYPEDEF))
              && psymbol_name_matches (*psym, lookup_name)
-             && (sym_matcher == NULL || sym_matcher (symbol_search_name (*psym))))
+             && (sym_matcher == NULL
+                 || sym_matcher (symbol_search_name (&(*psym)->ginfo))))
            {
              /* Found a match, so notify our caller.  */
              result = PST_SEARCHED_AND_FOUND;
@@ -1504,8 +1509,8 @@ sort_pst_symbols (struct objfile *objfile, struct partial_symtab *pst)
 
   std::sort (begin, end, [] (partial_symbol *s1, partial_symbol *s2)
     {
-      return strcmp_iw_ordered (symbol_search_name (s1),
-                               symbol_search_name (s2)) < 0;
+      return strcmp_iw_ordered (symbol_search_name (&s1->ginfo),
+                               symbol_search_name (&s2->ginfo)) < 0;
     });
 }
 
@@ -1552,18 +1557,18 @@ psymbol_hash (const void *addr, int length)
 {
   unsigned long h = 0;
   struct partial_symbol *psymbol = (struct partial_symbol *) addr;
-  unsigned int lang = psymbol->language;
+  unsigned int lang = psymbol->ginfo.language;
   unsigned int domain = psymbol->domain;
   unsigned int theclass = psymbol->aclass;
 
-  h = hash_continue (&psymbol->value, sizeof (psymbol->value), h);
+  h = hash_continue (&psymbol->ginfo.value, sizeof (psymbol->ginfo.value), h);
   h = hash_continue (&lang, sizeof (unsigned int), h);
   h = hash_continue (&domain, sizeof (unsigned int), h);
   h = hash_continue (&theclass, sizeof (unsigned int), h);
   /* Note that psymbol names are interned via symbol_set_names, so
      there's no need to hash the contents of the name here.  */
-  h = hash_continue (&psymbol->name,
-                    sizeof (psymbol->name), h);
+  h = hash_continue (&psymbol->ginfo.name,
+                    sizeof (psymbol->ginfo.name), h);
 
   return h;
 }
@@ -1578,15 +1583,15 @@ psymbol_compare (const void *addr1, const void *addr2, int length)
   struct partial_symbol *sym1 = (struct partial_symbol *) addr1;
   struct partial_symbol *sym2 = (struct partial_symbol *) addr2;
 
-  return (memcmp (&sym1->value, &sym2->value,
-                  sizeof (sym1->value)) == 0
-         && sym1->language == sym2->language
+  return (memcmp (&sym1->ginfo.value, &sym2->ginfo.value,
+                  sizeof (sym1->ginfo.value)) == 0
+         && sym1->ginfo.language == sym2->ginfo.language
           && sym1->domain == sym2->domain
           && sym1->aclass == sym2->aclass
          /* Note that psymbol names are interned via
             symbol_set_names, so there's no need to compare the
             contents of the name here.  */
-          && sym1->name == sym2->name);
+          && sym1->ginfo.name == sym2->ginfo.name);
 }
 
 /* Initialize a partial symbol bcache.  */
@@ -1651,17 +1656,16 @@ add_psymbol_to_bcache (const char *name, int namelength, int copy_name,
                       int *added)
 {
   struct partial_symbol psymbol;
+  memset (&psymbol, 0, sizeof (psymbol));
 
   psymbol.set_unrelocated_address (coreaddr);
-  psymbol.section = section;
+  psymbol.ginfo.section = section;
   psymbol.domain = domain;
   psymbol.aclass = theclass;
-
-  memset (&psymbol.language_specific, 0, sizeof (psymbol.language_specific));
-  psymbol.ada_mangled = 0;
-  symbol_set_language (&psymbol, language,
+  symbol_set_language (&psymbol.ginfo, language,
                       objfile->partial_symtabs->obstack ());
-  symbol_set_names (&psymbol, name, namelength, copy_name, objfile->per_bfd);
+  symbol_set_names (&psymbol.ginfo, name, namelength, copy_name,
+                   objfile->per_bfd);
 
   /* Stash the partial symbol away in the cache.  */
   return psymbol_bcache_full (&psymbol,
@@ -2183,13 +2187,13 @@ maintenance_check_psymtabs (const char *ignore, int from_tty)
        length = ps->n_static_syms;
        while (length--)
          {
-           sym = block_lookup_symbol (b, symbol_search_name (*psym),
+           sym = block_lookup_symbol (b, symbol_search_name (&(*psym)->ginfo),
                                       symbol_name_match_type::SEARCH_NAME,
                                       (*psym)->domain);
            if (!sym)
              {
                printf_filtered ("Static symbol `");
-               puts_filtered ((*psym)->name);
+               puts_filtered ((*psym)->ginfo.name);
                printf_filtered ("' only found in ");
                puts_filtered (ps->filename);
                printf_filtered (" psymtab\n");
@@ -2201,13 +2205,13 @@ maintenance_check_psymtabs (const char *ignore, int from_tty)
        length = ps->n_global_syms;
        while (length--)
          {
-           sym = block_lookup_symbol (b, symbol_search_name (*psym),
+           sym = block_lookup_symbol (b, symbol_search_name (&(*psym)->ginfo),
                                       symbol_name_match_type::SEARCH_NAME,
                                       (*psym)->domain);
            if (!sym)
              {
                printf_filtered ("Global symbol `");
-               puts_filtered ((*psym)->name);
+               puts_filtered ((*psym)->ginfo.name);
                printf_filtered ("' only found in ");
                puts_filtered (ps->filename);
                printf_filtered (" psymtab\n");