Introduce lookup_name_info and generalize Ada's FULL/WILD name matching

Summary:
 - This is preparation for supporting wild name matching on C++ too.
 - This is also preparation for TAB-completion fixes.
 - Makes symbol name matching (think strcmp_iw) be based on a per-language method.
 - Merges completion and non-completion name comparison (think
   language_ops::la_get_symbol_name_cmp generalized).
 - Avoid re-hashing lookup name multiple times
 - Centralizes preparing a name for lookup (Ada name encoding / C++ Demangling),
   both completion and non-completion.
 - Fixes Ada latent bug with verbatim name matches in expressions
 - Makes ada-lang.c use common|symtab.c completion code a bit more.

Ada's wild matching basically means that

 "(gdb) break foo"

will find all methods named "foo" in all packages.  Translating to
C++, it's roughly the same as saying that "break klass::method" sets
breakpoints on all "klass::method" methods of all classes, no matter
the namespace.  A following patch will teach GDB about fullname vs
wild matching for C++ too.  This patch is preparatory work to get
there.

Another idea here is to do symbol name matching based on the symbol
language's algorithm.  I.e., avoid dependency on current language set.

This allows for example doing

  (gdb) b foo::bar< int > (<tab>

and having gdb name match the C++ symbols correctly even if the
current language is C or Assembly (or Rust, or Ada, or ...), which can
easily happen if you step into an Assembly/C runtime library frame.

By encapsulating all the information related to a lookup name in a
class, we can also cache hash computation for a given language in the
lookup name object, to avoid recomputing it over and over.

Similarly, because we don't really know upfront which languages the
lookup name will be matched against, for each language we store the
lookup name transformed into a search name.  E.g., for C++, that means
demangling the name.  But for Ada, it means encoding the name.  This
actually forces us to centralize all the different lookup name
encoding in a central place, resulting in clearer code, IMO.  See
e.g., the new ada_lookup_name_info class.

The lookup name -> symbol search name computation is also done only
once per language.

The old language->la_get_symbol_name_cmp / symbol_name_cmp_ftype are
generalized to work with both completion, and normal symbol look up.

At some point early on, I had separate completion vs non-completion
language vector entry points, but a single method ends up being better
IMO for simplifying things -- the more we merge the completion /
non-completion name lookup code paths, the less changes for bugs
causing completion vs normal lookup finding different symbols.

The ada-lex.l change is necessary because when doing

  (gdb) p <UpperCase>

then the name that is passed to write_ write_var_or_type ->
ada_lookup_symbol_list misses the "<>", i.e., it's just "UpperCase",
and we end up doing a wild match against "UpperCase" lowercased by
ada_lookup_name_info's constructor.  I.e., "uppercase" wouldn't ever
match "UpperCase", and the symbol lookup fails.

This wouldn't cause any regression in the testsuite, but I added a new
test that would pass before the patch and fail after, if it weren't
for that fix.

This is latent bug that happens to go unnoticed because that
particular path was inconsistent with the rest of Ada symbol lookup by
not lowercasing the lookup name.

Ada's symbol_completion_add is deleted, replaced by using common
code's completion_list_add_name.  To make the latter work for Ada, we
needed to add a new output parameter, because Ada wants to return back
a custom completion candidates that are not the symbol name.

With this patch, minimal symbol demangled name hashing is made
consistent with regular symbol hashing.  I.e., it now goes via the
language vector's search_name_hash method too, as I had suggested in a
previous patch.

dw2_expand_symtabs_matching / .gdb_index symbol names were a
challenge.  The problem is that we have no way to telling what is the
language of each symbol name found in the index, until we expand the
corresponding full symbol, which is off course what we're trying to
avoid.  Language information is simply not considered in the index
format...  Since the symbol name hashing and comparison routines are
per-language, we now have a problem.  The patch sorts this out by
matching each name against all languages.  This is inneficient, and
indeed slows down completion several times.  E.g., with:

 $ cat script.cmd
 set pagination off
 set $count = 0
 while $count < 400
   complete b string_prin
   printf "count = %d\n", $count
   set $count = $count + 1
 end

 $ time gdb --batch -q ./gdb-with-index -ex "source script-string_printf.cmd"

I get, before patch (-O2, x86-64):

 real    0m1.773s
 user    0m1.737s
 sys     0m0.040s

While after patch (-O2, x86-64):

 real    0m9.843s
 user    0m9.482s
 sys     0m0.034s

However, the following patch will optimize this, and will actually
make this use case faster compared to the "before patch" above:

 real    0m1.321s
 user    0m1.285s
 sys     0m0.039s

gdb/ChangeLog:
2017-11-08   Pedro Alves  <palves@redhat.com>

	* ada-lang.c (ada_encode): Rename to ..
	(ada_encode_1): ... this.  Add throw_errors parameter and handle
	it.
	(ada_encode): Reimplement.
	(match_name): Delete, folded into full_name.
	(resolve_subexp): No longer pass the encoded name to
	ada_lookup_symbol_list.
	(should_use_wild_match): Delete.
	(name_match_type_from_name): New.
	(ada_lookup_simple_minsym): Use lookup_name_info and the
	language's symbol_name_matcher_ftype.
	(add_symbols_from_enclosing_procs, ada_add_local_symbols)
	(ada_add_block_renamings): Adjust to use lookup_name_info.
	(ada_lookup_name): New.
	(add_nonlocal_symbols, ada_add_all_symbols)
	(ada_lookup_symbol_list_worker, ada_lookup_symbol_list)
	(ada_iterate_over_symbols): Adjust to use lookup_name_info.
	(ada_name_for_lookup): Delete.
	(ada_lookup_encoded_symbol): Construct a verbatim name.
	(wild_match): Reverse sense of return type.  Use bool.
	(full_match): Reverse sense of return type.  Inline bits of old
	match_name here.
	(ada_add_block_symbols): Adjust to use lookup_name_info.
	(symbol_completion_match): Delete, folded into...
	(ada_lookup_name_info::matches): ... .this new method.
	(symbol_completion_add): Delete.
	(ada_collect_symbol_completion_matches): Add name_match_type
	parameter.  Adjust to use lookup_name_info and
	completion_list_add_name.
	(get_var_value, ada_add_global_exceptions): Adjust to use
	lookup_name_info.
	(ada_get_symbol_name_cmp): Delete.
	(do_wild_match, do_full_match): New functions.
	(ada_lookup_name_info::ada_lookup_name_info): New method.
	(ada_symbol_name_matches, ada_get_symbol_name_matcher): New
	functions.
	(ada_language_defn): Install ada_get_symbol_name_matcher.
	* ada-lex.l (processId): If name starts with '<', copy it
	verbatim.
	* block.c (block_iter_match_step, block_iter_match_first)
	(block_iter_match_next, block_lookup_symbol)
	(block_lookup_symbol_primary, block_find_symbol): Adjust to use
	lookup_name_info.
	* block.h (block_iter_match_first, block_iter_match_next)
	(ALL_BLOCK_SYMBOLS_WITH_NAME): Adjust to use lookup_name_info.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Adjust comments to
	refer to la_get_symbol_name_matcher.
	* completer.c (complete_files_symbols)
	(collect_explicit_location_matches, symbol_completer): Pass a
	symbol_name_match_type down.
	* completer.h (class completion_match, completion_match_result):
	New classes.
	(completion_tracker::reset_completion_match_result): New method.
	(completion_tracker::m_completion_match_result): New field.
	* cp-support.c (make_symbol_overload_list_block): Adjust to use
	lookup_name_info.
	(cp_fq_symbol_name_matches, cp_get_symbol_name_matcher): New
	functions.
	* cp-support.h (cp_get_symbol_name_matcher): New declaration.
	* d-lang.c: Adjust comments to refer to
	la_get_symbol_name_matcher.
	* dictionary.c (dict_vector) <iter_match_first, iter_match_next>:
	Adjust to use lookup_name_info.
	(dict_iter_match_first, dict_iter_match_next)
	(iter_match_first_hashed, iter_match_next_hashed)
	(iter_match_first_linear, iter_match_next_linear): Adjust to work
	with a lookup_name_info.
	* dictionary.h (dict_iter_match_first, dict_iter_match_next):
	Likewise.
	* dwarf2read.c (dw2_lookup_symbol): Adjust to use lookup_name_info.
	(dw2_map_matching_symbols): Adjust to use symbol_name_match_type.
	(gdb_index_symbol_name_matcher): New class.
	(dw2_expand_symtabs_matching) Adjust to use lookup_name_info and
	gdb_index_symbol_name_matcher.  Accept a NULL symbol_matcher.
	* f-lang.c (f_collect_symbol_completion_matches): Adjust to work
	with a symbol_name_match_type.
	(f_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* go-lang.c (go_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* language.c (default_symbol_name_matcher)
	(language_get_symbol_name_matcher): New functions.
	(unknown_language_defn, auto_language_defn): Adjust comments to
	refer to la_get_symbol_name_matcher.
	* language.h (symbol_name_cmp_ftype): Delete.
	(language_defn) <la_collect_symbol_completion_matches>: Add match
	type parameter.
	<la_get_symbol_name_cmp>: Delete field.
	<la_get_symbol_name_matcher>: New field.
	<la_iterate_over_symbols>: Adjust to use lookup_name_info.
	(default_symbol_name_matcher, language_get_symbol_name_matcher):
	Declare.
	* linespec.c (iterate_over_all_matching_symtabs)
	(iterate_over_file_blocks): Adjust to use lookup_name_info.
	(find_methods): Add language parameter, and use lookup_name_info
	and the language's symbol_name_matcher_ftype.
	(linespec_complete_function): Adjust.
	(lookup_prefix_sym): Use lookup_name_info.
	(add_all_symbol_names_from_pspace): Adjust.
	(find_superclass_methods): Add language parameter and pass it
	down.
	(find_method): Pass symbol language down.
	(find_linespec_symbols): Don't demangle or Ada encode here.
	(search_minsyms_for_name): Add lookup_name_info parameter.
	(add_matching_symbols_to_info): Add name_match_type parameter.
	Use lookup_name_info.
	* m2-lang.c (m2_language_defn): Adjust comments to refer to
	la_get_symbol_name_matcher.
	* minsyms.c: Include <algorithm>.
	(add_minsym_to_demangled_hash_table): Remove table parameter and
	add objfile parameter.  Use search_name_hash, and add language to
	demangled languages vector.
	(struct found_minimal_symbols): New struct.
	(lookup_minimal_symbol_mangled, lookup_minimal_symbol_demangled):
	New functions.
	(lookup_minimal_symbol): Adjust to use them.  Don't canonicalize
	input names here.  Use lookup_name_info instead.  Lookup up
	demangled names once for each language in the demangled names
	vector.
	(iterate_over_minimal_symbols): Use lookup_name_info.  Lookup up
	demangled names once for each language in the demangled names
	vector.
	(build_minimal_symbol_hash_tables): Adjust.
	* minsyms.h (iterate_over_minimal_symbols): Adjust to pass down a
	lookup_name_info.
	* objc-lang.c (objc_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* objfiles.h: Include <vector>.
	(objfile_per_bfd_storage) <demangled_hash_languages>: New field.
	* opencl-lang.c (opencl_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* p-lang.c (pascal_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* psymtab.c (psym_lookup_symbol): Use lookup_name_info.
	(match_partial_symbol): Use symbol_name_match_type,
	lookup_name_info and psymbol_name_matches.
	(lookup_partial_symbol): Use lookup_name_info.
	(map_block): Use symbol_name_match_type and lookup_name_info.
	(psym_map_matching_symbols): Use symbol_name_match_type.
	(psymbol_name_matches): New.
	(recursively_search_psymtabs): Use lookup_name_info and
	psymbol_name_matches.  Rename 'kind' parameter to 'domain'.
	(psym_expand_symtabs_matching): Use lookup_name_info.  Rename
	'kind' parameter to 'domain'.
	* rust-lang.c (rust_language_defn): Adjust comment to refer to
	la_get_symbol_name_matcher.
	* symfile-debug.c (debug_qf_map_matching_symbols)
	(debug_qf_map_matching_symbols): Use symbol_name_match_type.
	(debug_qf_expand_symtabs_matching): Use lookup_name_info.
	* symfile.c (expand_symtabs_matching): Use lookup_name_info.
	* symfile.h (quick_symbol_functions) <map_matching_symbols>:
	Adjust to use symbol_name_match_type.
	<expand_symtabs_matching>: Adjust to use lookup_name_info.
	(expand_symtabs_matching): Adjust to use lookup_name_info.
	* symmisc.c (maintenance_expand_symtabs): Use
	lookup_name_info::match_any ().
	* symtab.c (symbol_matches_search_name): New.
	(eq_symbol_entry): Adjust to use lookup_name_info and the
	language's matcher.
	(demangle_for_lookup_info::demangle_for_lookup_info): New.
	(lookup_name_info::match_any): New.
	(iterate_over_symbols, search_symbols): Use lookup_name_info.
	(compare_symbol_name): Add language, lookup_name_info and
	completion_match_result parameters, and use them.
	(completion_list_add_name): Make extern.  Add language and
	lookup_name_info parameters.  Use them.
	(completion_list_add_symbol, completion_list_add_msymbol)
	(completion_list_objc_symbol): Add lookup_name_info parameters and
	adjust.  Pass down language.
	(completion_list_add_fields): Add lookup_name_info parameters and
	adjust.  Pass down language.
	(add_symtab_completions): Add lookup_name_info parameters and
	adjust.
	(default_collect_symbol_completion_matches_break_on): Add
	name_match_type parameter, and use it.  Use lookup_name_info.
	(default_collect_symbol_completion_matches)
	(collect_symbol_completion_matches): Add name_match_type
	parameter, and pass it down.
	(collect_symbol_completion_matches_type): Adjust.
	(collect_file_symbol_completion_matches): Add name_match_type
	parameter, and use lookup_name_info.
	* symtab.h: Include <string> and "common/gdb_optional.h".
	(enum class symbol_name_match_type): New.
	(class ada_lookup_name_info): New.
	(struct demangle_for_lookup_info): New.
	(class lookup_name_info): New.
	(symbol_name_matcher_ftype): New.
	(SYMBOL_MATCHES_SEARCH_NAME): Use symbol_matches_search_name.
	(symbol_matches_search_name): Declare.
	(MSYMBOL_MATCHES_SEARCH_NAME): Delete.
	(default_collect_symbol_completion_matches)
	(collect_symbol_completion_matches)
	(collect_file_symbol_completion_matches): Add name_match_type
	parameter.
	(iterate_over_symbols): Use lookup_name_info.
	(completion_list_add_name): Declare.
	* utils.c (enum class strncmp_iw_mode): Moved to utils.h.
	(strncmp_iw_with_mode): Now extern.
	* utils.h (enum class strncmp_iw_mode): Moved from utils.c.
	(strncmp_iw_with_mode): Declare.

gdb/testsuite/ChangeLog:
2017-11-08   Pedro Alves  <palves@redhat.com>

	* gdb.ada/complete.exp (p <Exported_Capitalized>): New test.
	(p Exported_Capitalized): New test.
	(p exported_capitalized): New test.

1 files changed, 230 insertions, 139 deletions

diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index 37edbd8..a0d3bd5 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -51,6 +51,7 @@
 #include "language.h"
 #include "cli/cli-utils.h"
 #include "symbol.h"
+#include <algorithm>
 
 /* See minsyms.h.  */
 
@@ -131,15 +132,139 @@ add_minsym_to_hash_table (struct minimal_symbol *sym,
    TABLE.  */
 static void
 add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
-                                  struct minimal_symbol **table)
+				    struct objfile *objfile)
 {
   if (sym->demangled_hash_next == NULL)
     {
-      unsigned int hash = msymbol_hash_iw (MSYMBOL_SEARCH_NAME (sym))
-	% MINIMAL_SYMBOL_HASH_SIZE;
+      unsigned int hash = search_name_hash (MSYMBOL_LANGUAGE (sym),
+					    MSYMBOL_SEARCH_NAME (sym));
+
+      auto &vec = objfile->per_bfd->demangled_hash_languages;
+      auto it = std::lower_bound (vec.begin (), vec.end (),
+				  MSYMBOL_LANGUAGE (sym));
+      if (it == vec.end () || *it != MSYMBOL_LANGUAGE (sym))
+	vec.insert (it, MSYMBOL_LANGUAGE (sym));
+
+      struct minimal_symbol **table
+	= objfile->per_bfd->msymbol_demangled_hash;
+      unsigned int hash_index = hash % MINIMAL_SYMBOL_HASH_SIZE;
+      sym->demangled_hash_next = table[hash_index];
+      table[hash_index] = sym;
+    }
+}
 
-      sym->demangled_hash_next = table[hash];
-      table[hash] = sym;
+/* Worker object for lookup_minimal_symbol.  Stores temporary results
+   while walking the symbol tables.  */
+
+struct found_minimal_symbols
+{
+  /* External symbols are best.  */
+  bound_minimal_symbol external_symbol {};
+
+  /* File-local symbols are next best.  */
+  bound_minimal_symbol file_symbol {};
+
+  /* Symbols for shared library trampolines are next best.  */
+  bound_minimal_symbol trampoline_symbol {};
+
+  /* Called when a symbol name matches.  Check if the minsym is a
+     better type than what we had already found, and record it in one
+     of the members fields if so.  Returns true if we collected the
+     real symbol, in which case we can stop searching.  */
+  bool maybe_collect (const char *sfile, objfile *objf,
+		      minimal_symbol *msymbol);
+};
+
+/* See declaration above.  */
+
+bool
+found_minimal_symbols::maybe_collect (const char *sfile,
+				      struct objfile *objfile,
+				      minimal_symbol *msymbol)
+{
+  switch (MSYMBOL_TYPE (msymbol))
+    {
+    case mst_file_text:
+    case mst_file_data:
+    case mst_file_bss:
+      if (sfile == NULL
+	  || filename_cmp (msymbol->filename, sfile) == 0)
+	{
+	  file_symbol.minsym = msymbol;
+	  file_symbol.objfile = objfile;
+	}
+      break;
+
+    case mst_solib_trampoline:
+
+      /* If a trampoline symbol is found, we prefer to keep
+	 looking for the *real* symbol.  If the actual symbol
+	 is not found, then we'll use the trampoline
+	 entry.  */
+      if (trampoline_symbol.minsym == NULL)
+	{
+	  trampoline_symbol.minsym = msymbol;
+	  trampoline_symbol.objfile = objfile;
+	}
+      break;
+
+    case mst_unknown:
+    default:
+      external_symbol.minsym = msymbol;
+      external_symbol.objfile = objfile;
+      /* We have the real symbol.  No use looking further.  */
+      return true;
+    }
+
+  /* Keep looking.  */
+  return false;
+}
+
+/* Walk the mangled name hash table, and pass each symbol whose name
+   matches LOOKUP_NAME according to NAMECMP to FOUND.  */
+
+static void
+lookup_minimal_symbol_mangled (const char *lookup_name,
+			       const char *sfile,
+			       struct objfile *objfile,
+			       struct minimal_symbol **table,
+			       unsigned int hash,
+			       int (*namecmp) (const char *, const char *),
+			       found_minimal_symbols &found)
+{
+  for (minimal_symbol *msymbol = table[hash];
+       msymbol != NULL;
+       msymbol = msymbol->hash_next)
+    {
+      const char *symbol_name = MSYMBOL_LINKAGE_NAME (msymbol);
+
+      if (namecmp (symbol_name, lookup_name) == 0
+	  && found.maybe_collect (sfile, objfile, msymbol))
+	return;
+    }
+}
+
+/* Walk the demangled name hash table, and pass each symbol whose name
+   matches LOOKUP_NAME according to MATCHER to FOUND.  */
+
+static void
+lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name,
+				 const char *sfile,
+				 struct objfile *objfile,
+				 struct minimal_symbol **table,
+				 unsigned int hash,
+				 symbol_name_matcher_ftype *matcher,
+				 found_minimal_symbols &found)
+{
+  for (minimal_symbol *msymbol = table[hash];
+       msymbol != NULL;
+       msymbol = msymbol->demangled_hash_next)
+    {
+      const char *symbol_name = MSYMBOL_SEARCH_NAME (msymbol);
+
+      if (matcher (symbol_name, lookup_name, NULL)
+	  && found.maybe_collect (sfile, objfile, msymbol))
+	return;
     }
 }
 
@@ -168,32 +293,22 @@ lookup_minimal_symbol (const char *name, const char *sfile,
 		       struct objfile *objf)
 {
   struct objfile *objfile;
-  struct bound_minimal_symbol found_symbol = { NULL, NULL };
-  struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
-  struct bound_minimal_symbol trampoline_symbol = { NULL, NULL };
+  found_minimal_symbols found;
 
-  unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
-  unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
+  unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
 
-  const char *modified_name = name;
+  auto *mangled_cmp
+    = (case_sensitivity == case_sensitive_on
+       ? strcmp
+       : strcasecmp);
 
   if (sfile != NULL)
     sfile = lbasename (sfile);
 
-  /* For C++, canonicalize the input name.  */
-  std::string modified_name_storage;
-  if (current_language->la_language == language_cplus)
-    {
-      std::string cname = cp_canonicalize_string (name);
-      if (!cname.empty ())
-	{
-	  std::swap (modified_name_storage, cname);
-	  modified_name = modified_name_storage.c_str ();
-	}
-    }
+  lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
 
   for (objfile = object_files;
-       objfile != NULL && found_symbol.minsym == NULL;
+       objfile != NULL && found.external_symbol.minsym == NULL;
        objfile = objfile->next)
     {
       struct minimal_symbol *msymbol;
@@ -201,131 +316,95 @@ lookup_minimal_symbol (const char *name, const char *sfile,
       if (objf == NULL || objf == objfile
 	  || objf == objfile->separate_debug_objfile_backlink)
 	{
+	  if (symbol_lookup_debug)
+	    {
+	      fprintf_unfiltered (gdb_stdlog,
+				  "lookup_minimal_symbol (%s, %s, %s)\n",
+				  name, sfile != NULL ? sfile : "NULL",
+				  objfile_debug_name (objfile));
+	    }
+
 	  /* Do two passes: the first over the ordinary hash table,
 	     and the second over the demangled hash table.  */
-        int pass;
-
-	if (symbol_lookup_debug)
-	  {
-	    fprintf_unfiltered (gdb_stdlog,
-				"lookup_minimal_symbol (%s, %s, %s)\n",
-				name, sfile != NULL ? sfile : "NULL",
-				objfile_debug_name (objfile));
-	  }
+	  lookup_minimal_symbol_mangled (name, sfile, objfile,
+					 objfile->per_bfd->msymbol_hash,
+					 mangled_hash, mangled_cmp, found);
 
-        for (pass = 1; pass <= 2 && found_symbol.minsym == NULL; pass++)
+	  /* If not found, try the demangled hash table.  */
+	  if (found.external_symbol.minsym == NULL)
 	    {
-            /* Select hash list according to pass.  */
-            if (pass == 1)
-              msymbol = objfile->per_bfd->msymbol_hash[hash];
-            else
-              msymbol = objfile->per_bfd->msymbol_demangled_hash[dem_hash];
-
-            while (msymbol != NULL && found_symbol.minsym == NULL)
+	      /* Once for each language in the demangled hash names
+		 table (usually just zero or one languages).  */
+	      for (auto lang : objfile->per_bfd->demangled_hash_languages)
 		{
-		  int match;
-
-		  if (pass == 1)
-		    {
-		      int (*cmp) (const char *, const char *);
-
-		      cmp = (case_sensitivity == case_sensitive_on
-		             ? strcmp : strcasecmp);
-		      match = cmp (MSYMBOL_LINKAGE_NAME (msymbol),
-				   modified_name) == 0;
-		    }
-		  else
-		    {
-		      /* The function respects CASE_SENSITIVITY.  */
-		      match = MSYMBOL_MATCHES_SEARCH_NAME (msymbol,
-							  modified_name);
-		    }
-
-		  if (match)
-		    {
-                    switch (MSYMBOL_TYPE (msymbol))
-                      {
-                      case mst_file_text:
-                      case mst_file_data:
-                      case mst_file_bss:
-                        if (sfile == NULL
-			    || filename_cmp (msymbol->filename, sfile) == 0)
-			  {
-			    found_file_symbol.minsym = msymbol;
-			    found_file_symbol.objfile = objfile;
-			  }
-                        break;
-
-                      case mst_solib_trampoline:
-
-                        /* If a trampoline symbol is found, we prefer to
-                           keep looking for the *real* symbol.  If the
-                           actual symbol is not found, then we'll use the
-                           trampoline entry.  */
-                        if (trampoline_symbol.minsym == NULL)
-			  {
-			    trampoline_symbol.minsym = msymbol;
-			    trampoline_symbol.objfile = objfile;
-			  }
-                        break;
-
-                      case mst_unknown:
-                      default:
-                        found_symbol.minsym = msymbol;
-			found_symbol.objfile = objfile;
-                        break;
-                      }
-		    }
-
-                /* Find the next symbol on the hash chain.  */
-                if (pass == 1)
-                  msymbol = msymbol->hash_next;
-                else
-                  msymbol = msymbol->demangled_hash_next;
+		  unsigned int hash
+		    = (lookup_name.search_name_hash (lang)
+		       % MINIMAL_SYMBOL_HASH_SIZE);
+
+		  symbol_name_matcher_ftype *match
+		    = language_get_symbol_name_matcher (language_def (lang),
+							lookup_name);
+		  struct minimal_symbol **msymbol_demangled_hash
+		    = objfile->per_bfd->msymbol_demangled_hash;
+
+		  lookup_minimal_symbol_demangled (lookup_name, sfile, objfile,
+						   msymbol_demangled_hash,
+						   hash, match, found);
+
+		  if (found.external_symbol.minsym != NULL)
+		    break;
 		}
 	    }
 	}
     }
 
   /* External symbols are best.  */
-  if (found_symbol.minsym != NULL)
+  if (found.external_symbol.minsym != NULL)
     {
       if (symbol_lookup_debug)
 	{
+	  minimal_symbol *minsym = found.external_symbol.minsym;
+
 	  fprintf_unfiltered (gdb_stdlog,
-			      "lookup_minimal_symbol (...) = %s"
-			      " (external)\n",
-			      host_address_to_string (found_symbol.minsym));
+			      "lookup_minimal_symbol (...) = %s (external)\n",
+			      host_address_to_string (minsym));
 	}
-      return found_symbol;
+      return found.external_symbol;
     }
 
   /* File-local symbols are next best.  */
-  if (found_file_symbol.minsym != NULL)
+  if (found.file_symbol.minsym != NULL)
     {
       if (symbol_lookup_debug)
 	{
+	  minimal_symbol *minsym = found.file_symbol.minsym;
+
 	  fprintf_unfiltered (gdb_stdlog,
-			      "lookup_minimal_symbol (...) = %s"
-			      " (file-local)\n",
-			      host_address_to_string
-			        (found_file_symbol.minsym));
+			      "lookup_minimal_symbol (...) = %s (file-local)\n",
+			      host_address_to_string (minsym));
 	}
-      return found_file_symbol;
+      return found.file_symbol;
     }
 
   /* Symbols for shared library trampolines are next best.  */
-  if (symbol_lookup_debug)
+  if (found.trampoline_symbol.minsym != NULL)
     {
-      fprintf_unfiltered (gdb_stdlog,
-			  "lookup_minimal_symbol (...) = %s%s\n",
-			  trampoline_symbol.minsym != NULL
-			  ? host_address_to_string (trampoline_symbol.minsym)
-			  : "NULL",
-			  trampoline_symbol.minsym != NULL
-			  ? " (trampoline)" : "");
+      if (symbol_lookup_debug)
+	{
+	  minimal_symbol *minsym = found.trampoline_symbol.minsym;
+
+	  fprintf_unfiltered (gdb_stdlog,
+			      "lookup_minimal_symbol (...) = %s (trampoline)\n",
+			      host_address_to_string (minsym));
+	}
+
+      return found.trampoline_symbol;
     }
-  return trampoline_symbol;
+
+  /* Not found.  */
+  if (symbol_lookup_debug)
+    fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
+  return {};
 }
 
 /* See minsyms.h.  */
@@ -354,34 +433,47 @@ find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
 /* See minsyms.h.  */
 
 void
-iterate_over_minimal_symbols (struct objfile *objf, const char *name,
+iterate_over_minimal_symbols (struct objfile *objf,
+			      const lookup_name_info &lookup_name,
 			      void (*callback) (struct minimal_symbol *,
 						void *),
 			      void *user_data)
 {
-  unsigned int hash;
-  struct minimal_symbol *iter;
-  int (*cmp) (const char *, const char *);
 
   /* The first pass is over the ordinary hash table.  */
-  hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
-  iter = objf->per_bfd->msymbol_hash[hash];
-  cmp = (case_sensitivity == case_sensitive_on ? strcmp : strcasecmp);
-  while (iter)
     {
-      if (cmp (MSYMBOL_LINKAGE_NAME (iter), name) == 0)
-	(*callback) (iter, user_data);
-      iter = iter->hash_next;
+      const char *name = lookup_name.name ().c_str ();
+      unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
+      auto *mangled_cmp
+	= (case_sensitivity == case_sensitive_on
+	   ? strcmp
+	   : strcasecmp);
+
+      for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash];
+	   iter != NULL;
+	   iter = iter->hash_next)
+	{
+	  if (mangled_cmp (MSYMBOL_LINKAGE_NAME (iter), name) == 0)
+	    (*callback) (iter, user_data);
+	}
     }
 
-  /* The second pass is over the demangled table.  */
-  hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
-  iter = objf->per_bfd->msymbol_demangled_hash[hash];
-  while (iter)
+  /* The second pass is over the demangled table.  Once for each
+     language in the demangled hash names table (usually just zero or
+     one).  */
+  for (auto lang : objf->per_bfd->demangled_hash_languages)
     {
-      if (MSYMBOL_MATCHES_SEARCH_NAME (iter, name))
-	(*callback) (iter, user_data);
-      iter = iter->demangled_hash_next;
+      const language_defn *lang_def = language_def (lang);
+      symbol_name_matcher_ftype *name_match
+	= language_get_symbol_name_matcher (lang_def, lookup_name);
+
+      unsigned int hash
+	= lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE;
+      for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash];
+	   iter != NULL;
+	   iter = iter->demangled_hash_next)
+	if (name_match (MSYMBOL_SEARCH_NAME (iter), lookup_name, NULL))
+	  (*callback) (iter, user_data);
     }
 }
 
@@ -1187,8 +1279,7 @@ build_minimal_symbol_hash_tables (struct objfile *objfile)
 
       msym->demangled_hash_next = 0;
       if (MSYMBOL_SEARCH_NAME (msym) != MSYMBOL_LINKAGE_NAME (msym))
-	add_minsym_to_demangled_hash_table (msym,
-                                            objfile->per_bfd->msymbol_demangled_hash);
+	add_minsym_to_demangled_hash_table (msym, objfile);
     }
 }