Use gdb::function_view in iterate_over_symtabs & co

I wanted to pass a lambda to iterate_over_symtabs (see following
patch), so I converted it to function_view, and then the rest is
cascaded from that.

This gets rid of a bunch of single-use callback functions and
corresponding manually managed callback capture types
(add_partial_datum, search_symbols_data, etc.) in favor of letting the
compiler generate them for us by using lambdas with a capture.  In a
couple cases, it was more natural to convert the existing function
callbacks to function objects (i.e., operator(), e.g.,
decode_compound_collector).

gdb/ChangeLog:
2017-02-23  Pedro Alves  <palves@redhat.com>

	* ada-lang.c: Include "common/function-view.h".
	(ada_iterate_over_symbols): Adjust to use function_view as
	callback type.
	(struct add_partial_datum, ada_complete_symbol_matcher): Delete.
	(ada_make_symbol_completion_list): Use a lambda.
	(ada_exc_search_name_matches): Delete.
	(name_matches_regex): New.
	(ada_add_global_exceptions): Use a lambda and name_matches_regex.
	* compile/compile-c-support.c: Include "common/function-view.h".
	(print_one_macro): Change prototype to accept a ui_file pointer.
	(write_macro_definitions): Use a lambda.
	* dwarf2read.c: Include "common/function-view.h".
	(dw2_map_expand_apply, dw2_map_symtabs_matching_filename)
	(dw2_expand_symtabs_matching): Adjust to use function_view as
	callback type.
	* language.h: Include "common/function-view.h".
	(struct language_defn) <la_iterate_over_symbols>: Adjust to use
	function_view as callback type.
	(LA_ITERATE_OVER_SYMBOLS): Remove DATA parameter.
	* linespec.c: Include "common/function-view.h".
	(collect_info::add_symbol): New method.
	(struct symbol_and_data_callback, iterate_inline_only, struct
	symbol_matcher_data, iterate_name_matcher): Delete.
	(iterate_over_all_matching_symtabs): Adjust to use function_view
	as callback type and lambdas.
	(iterate_over_file_blocks): Adjust to use function_view as
	callback type.
	(decode_compound_collector): Now a class with private fields.
	(decode_compound_collector::release_symbols): New method.
	(collect_one_symbol): Rename to...
	(decode_compound_collector::operator()): ... this and adjust.
	(lookup_prefix_sym): decode_compound_collector construction bits
	move to decode_compound_collector ctor.  Pass the
	decode_compound_collector object directly as callback.  Remove
	cleanups and use decode_compound_collector::release_symbols
	instead.
	(symtab_collector): Now a class with private fields.
	(symtab_collector::release_symtabs): New method.
	(add_symtabs_to_list): Rename to...
	(symtab_collector::operator()): ... this and adjust.
	(collect_symtabs_from_filename): symtab_collector construction
	bits move to symtab_collector ctor.  Pass the symtab_collector
	object directly as callback.  Remove cleanups and use
	symtab_collector::release_symtabs instead.
	(collect_symbols): Delete.
	(add_matching_symbols_to_info): Use lambdas.
	* macrocmd.c (print_macro_callback): Delete.
	(info_macro_command): Use a lambda.
	(info_macros_command): Pass print_macro_definition as callable
	directly.
	(print_one_macro): Remove 'ignore' parameter.
	(macro_list_command): Adjust.
	* macrotab.c (macro_for_each_data::fn): Now a function_view.
	(macro_for_each_data::user_data): Delete field.
	(foreach_macro): Adjust to call the function_view.
	(macro_for_each): Adjust to use function_view as callback type.
	(foreach_macro_in_scope): Adjust to call the function_view.
	(macro_for_each_in_scope): Adjust to use function_view as callback
	type.
	* macrotab.h: Include "common/function-view.h".
	(macro_callback_fn): Declare a prototype instead of a pointer.
	Remove "user_data" parameter.
	(macro_for_each, macro_for_each_in_scope): Adjust to use
	function_view as callback type.
	* psymtab.c (partial_map_expand_apply)
	(psym_map_symtabs_matching_filename, recursively_search_psymtabs):
	Adjust to use function_view as callback type and to return bool.
	(psym_expand_symtabs_matching): Adjust to use function_view as
	callback types.
	* symfile-debug.c (debug_qf_map_symtabs_matching_filename): Adjust
	to use function_view as callback type and to return bool.
	(debug_qf_expand_symtabs_matching): Adjust to use function_view as
	callback types.
	* symfile.c (expand_symtabs_matching): Adjust to use function_view
	as callback types.
	* symfile.h: Include "common/function-view.h".
	(expand_symtabs_file_matcher_ftype)
	(expand_symtabs_symbol_matcher_ftype)
	(expand_symtabs_exp_notify_ftype): Remove "data" parameter and
	return bool.
	(quick_symbol_functions::map_symtabs_matching_filename)
	(quick_symbol_functions::expand_symtabs_matching): Adjust to use
	function_view as callback type and return bool.
	(expand_symtabs_matching): Adjust to use function_view as callback
	type.
	(maintenance_expand_name_matcher)
	(maintenance_expand_file_matcher): Delete.
	(maintenance_expand_symtabs): Use lambdas.
	* symtab.c (iterate_over_some_symtabs): Adjust to use
	function_view as callback types and return bool.
	(iterate_over_symtabs): Likewise.  Use unique_xmalloc_ptr instead
	of a cleanup.
	(lookup_symtab_callback): Delete.
	(lookup_symtab): Use a lambda.
	(iterate_over_symbols): Adjust to use function_view as callback
	type.
	(struct search_symbols_data, search_symbols_file_matches)
	(search_symbols_name_matches): Delete.
	(search_symbols): Use a pair of lambdas.
	(struct add_name_data, add_macro_name, symbol_completion_matcher)
	(symtab_expansion_callback): Delete.
	(default_make_symbol_completion_list_break_on_1): Use lambdas.
	* symtab.h: Include "common/function-view.h".
	(iterate_over_some_symtabs): Adjust to use function_view as
	callback type and return bool.
	(iterate_over_symtabs): Adjust to use function_view as callback
	type.
	(symbol_found_callback_ftype): Remove 'data' parameter and return
	bool.
	(iterate_over_symbols): Adjust to use function_view as callback
	type.

1 files changed, 136 insertions, 177 deletions

diff --git a/gdb/linespec.c b/gdb/linespec.c
index 630802690d..72bcd604ff 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -44,6 +44,7 @@
 #include "ada-lang.h"
 #include "stack.h"
 #include "location.h"
+#include "common/function-view.h"
 
 typedef struct symbol *symbolp;
 DEF_VEC_P (symbolp);
@@ -171,8 +172,23 @@ struct collect_info
     VEC (symbolp) *symbols;
     VEC (bound_minimal_symbol_d) *minimal_symbols;
   } result;
+
+  /* Possibly add a symbol to the results.  */
+  bool add_symbol (symbol *sym);
 };
 
+bool
+collect_info::add_symbol (symbol *sym)
+{
+  /* In list mode, add all matching symbols, regardless of class.
+     This allows the user to type "list a_global_variable".  */
+  if (SYMBOL_CLASS (sym) == LOC_BLOCK || this->state->list_mode)
+    VEC_safe_push (symbolp, this->result.symbols, sym);
+
+  /* Continue iterating.  */
+  return true;
+}
+
 /* Token types  */
 
 enum ls_token_type
@@ -264,10 +280,9 @@ typedef struct ls_parser linespec_parser;
 
 /* Prototypes for local functions.  */
 
-static void iterate_over_file_blocks (struct symtab *symtab,
-				      const char *name, domain_enum domain,
-				      symbol_found_callback_ftype *callback,
-				      void *data);
+static void iterate_over_file_blocks
+  (struct symtab *symtab, const char *name, domain_enum domain,
+   gdb::function_view<symbol_found_callback_ftype> callback);
 
 static void initialize_defaults (struct symtab **default_symtab,
 				 int *default_line);
@@ -916,83 +931,26 @@ maybe_add_address (htab_t set, struct program_space *pspace, CORE_ADDR addr)
   return 1;
 }
 
-/* A callback function and the additional data to call it with.  */
-
-struct symbol_and_data_callback
-{
-  /* The callback to use.  */
-  symbol_found_callback_ftype *callback;
-
-  /* Data to be passed to the callback.  */
-  void *data;
-};
-
-/* A helper for iterate_over_all_matching_symtabs that is used to
-   restrict calls to another callback to symbols representing inline
-   symbols only.  */
-
-static int
-iterate_inline_only (struct symbol *sym, void *d)
-{
-  if (SYMBOL_INLINED (sym))
-    {
-      struct symbol_and_data_callback *cad
-	= (struct symbol_and_data_callback *) d;
-
-      return cad->callback (sym, cad->data);
-    }
-  return 1; /* Continue iterating.  */
-}
-
-/* Some data for the expand_symtabs_matching callback.  */
-
-struct symbol_matcher_data
-{
-  /* The lookup name against which symbol name should be compared.  */
-  const char *lookup_name;
-
-  /* The routine to be used for comparison.  */
-  symbol_name_cmp_ftype symbol_name_cmp;
-};
-
-/* A helper for iterate_over_all_matching_symtabs that is passed as a
-   callback to the expand_symtabs_matching method.  */
-
-static int
-iterate_name_matcher (const char *name, void *d)
-{
-  const struct symbol_matcher_data *data
-    = (const struct symbol_matcher_data *) d;
-
-  if (data->symbol_name_cmp (name, data->lookup_name) == 0)
-    return 1; /* Expand this symbol's symbol table.  */
-  return 0; /* Skip this symbol.  */
-}
-
 /* A helper that walks over all matching symtabs in all objfiles and
    calls CALLBACK for each symbol matching NAME.  If SEARCH_PSPACE is
    not NULL, then the search is restricted to just that program
-   space.  If INCLUDE_INLINE is nonzero then symbols representing
+   space.  If INCLUDE_INLINE is true then symbols representing
    inlined instances of functions will be included in the result.  */
 
 static void
-iterate_over_all_matching_symtabs (struct linespec_state *state,
-				   const char *name,
-				   const domain_enum domain,
-				   symbol_found_callback_ftype *callback,
-				   void *data,
-				   struct program_space *search_pspace,
-				   int include_inline)
+iterate_over_all_matching_symtabs
+  (struct linespec_state *state, const char *name, const domain_enum domain,
+   struct program_space *search_pspace, bool include_inline,
+   gdb::function_view<symbol_found_callback_ftype> callback)
 {
   struct objfile *objfile;
   struct program_space *pspace;
-  struct symbol_matcher_data matcher_data;
 
-  matcher_data.lookup_name = name;
-  matcher_data.symbol_name_cmp =
-    state->language->la_get_symbol_name_cmp != NULL
-    ? state->language->la_get_symbol_name_cmp (name)
-    : strcmp_iw;
+  /* The routine to be used for comparison.  */
+  symbol_name_cmp_ftype symbol_name_cmp
+    = (state->language->la_get_symbol_name_cmp != NULL
+       ? state->language->la_get_symbol_name_cmp (name)
+       : strcmp_iw);
 
   ALL_PSPACES (pspace)
   {
@@ -1008,20 +966,24 @@ iterate_over_all_matching_symtabs (struct linespec_state *state,
       struct compunit_symtab *cu;
 
       if (objfile->sf)
-	objfile->sf->qf->expand_symtabs_matching (objfile, NULL,
-						  iterate_name_matcher,
-						  NULL, ALL_DOMAIN,
-						  &matcher_data);
+	objfile->sf->qf->expand_symtabs_matching
+	  (objfile,
+	   NULL,
+	   [&] (const char *symbol_name)
+	   {
+	     return symbol_name_cmp (symbol_name, name) == 0;
+	   },
+	   NULL,
+	   ALL_DOMAIN);
 
       ALL_OBJFILE_COMPUNITS (objfile, cu)
 	{
 	  struct symtab *symtab = COMPUNIT_FILETABS (cu);
 
-	  iterate_over_file_blocks (symtab, name, domain, callback, data);
+	  iterate_over_file_blocks (symtab, name, domain, callback);
 
 	  if (include_inline)
 	    {
-	      struct symbol_and_data_callback cad = { callback, data };
 	      struct block *block;
 	      int i;
 
@@ -1031,7 +993,14 @@ iterate_over_all_matching_symtabs (struct linespec_state *state,
 		{
 		  block = BLOCKVECTOR_BLOCK (SYMTAB_BLOCKVECTOR (symtab), i);
 		  state->language->la_iterate_over_symbols
-		    (block, name, domain, iterate_inline_only, &cad);
+		    (block, name, domain, [&] (symbol *sym)
+		     {
+		       /* Restrict calls to CALLBACK to symbols
+			  representing inline symbols only.  */
+		       if (SYMBOL_INLINED (sym))
+			 return callback (sym);
+		       return true;
+		     });
 		}
 	    }
 	}
@@ -1060,16 +1029,16 @@ get_current_search_block (void)
 /* Iterate over static and global blocks.  */
 
 static void
-iterate_over_file_blocks (struct symtab *symtab,
-			  const char *name, domain_enum domain,
-			  symbol_found_callback_ftype *callback, void *data)
+iterate_over_file_blocks
+  (struct symtab *symtab, const char *name, domain_enum domain,
+   gdb::function_view<symbol_found_callback_ftype> callback)
 {
   struct block *block;
 
   for (block = BLOCKVECTOR_BLOCK (SYMTAB_BLOCKVECTOR (symtab), STATIC_BLOCK);
        block != NULL;
        block = BLOCK_SUPERBLOCK (block))
-    LA_ITERATE_OVER_SYMBOLS (block, name, domain, callback, data);
+    LA_ITERATE_OVER_SYMBOLS (block, name, domain, callback);
 }
 
 /* A helper for find_method.  This finds all methods in type T which
@@ -2824,60 +2793,70 @@ decode_objc (struct linespec_state *self, linespec_p ls, const char *arg)
   return values;
 }
 
-/* An instance of this type is used when collecting prefix symbols for
-   decode_compound.  */
-
-struct decode_compound_collector
+/* A function object that serves as symbol_found_callback_ftype
+   callback for iterate_over_symbols.  This is used by
+   lookup_prefix_sym to collect type symbols.  */
+class decode_compound_collector
 {
-  /* The result vector.  */
-  VEC (symbolp) *symbols;
-
-  /* A hash table of all symbols we found.  We use this to avoid
-     adding any symbol more than once.  */
-  htab_t unique_syms;
-
+public:
   decode_compound_collector ()
-  : symbols (NULL),
-    unique_syms (NULL)
+    : m_symbols (NULL)
   {
+    m_unique_syms = htab_create_alloc (1, htab_hash_pointer,
+				       htab_eq_pointer, NULL,
+				       xcalloc, xfree);
   }
 
   ~decode_compound_collector ()
   {
-    if (unique_syms != NULL)
-      htab_delete (unique_syms);
+    if (m_unique_syms != NULL)
+      htab_delete (m_unique_syms);
   }
-};
 
-/* A callback for iterate_over_symbols that is used by
-   lookup_prefix_sym to collect type symbols.  */
+  /* Releases ownership of the collected symbols and returns them.  */
+  VEC (symbolp) *release_symbols ()
+  {
+    VEC (symbolp) *res = m_symbols;
+    m_symbols = NULL;
+    return res;
+  }
 
-static int
-collect_one_symbol (struct symbol *sym, void *d)
+  /* Callable as a symbol_found_callback_ftype callback.  */
+  bool operator () (symbol *sym);
+
+private:
+  /* A hash table of all symbols we found.  We use this to avoid
+     adding any symbol more than once.  */
+  htab_t m_unique_syms;
+
+  /* The result vector.  */
+  VEC (symbolp) *m_symbols;
+};
+
+bool
+decode_compound_collector::operator () (symbol *sym)
 {
-  struct decode_compound_collector *collector
-    = (struct decode_compound_collector *) d;
   void **slot;
   struct type *t;
 
   if (SYMBOL_CLASS (sym) != LOC_TYPEDEF)
-    return 1; /* Continue iterating.  */
+    return true; /* Continue iterating.  */
 
   t = SYMBOL_TYPE (sym);
   t = check_typedef (t);
   if (TYPE_CODE (t) != TYPE_CODE_STRUCT
       && TYPE_CODE (t) != TYPE_CODE_UNION
       && TYPE_CODE (t) != TYPE_CODE_NAMESPACE)
-    return 1; /* Continue iterating.  */
+    return true; /* Continue iterating.  */
 
-  slot = htab_find_slot (collector->unique_syms, sym, INSERT);
+  slot = htab_find_slot (m_unique_syms, sym, INSERT);
   if (!*slot)
     {
       *slot = sym;
-      VEC_safe_push (symbolp, collector->symbols, sym);
+      VEC_safe_push (symbolp, m_symbols, sym);
     }
 
-  return 1; /* Continue iterating.  */
+  return true; /* Continue iterating.  */
 }
 
 /* Return any symbols corresponding to CLASS_NAME in FILE_SYMTABS.  */
@@ -2888,27 +2867,16 @@ lookup_prefix_sym (struct linespec_state *state, VEC (symtab_ptr) *file_symtabs,
 {
   int ix;
   struct symtab *elt;
-  struct decode_compound_collector collector;
-  struct cleanup *outer;
-  struct cleanup *cleanup;
-
-  collector.symbols = NULL;
-  outer = make_cleanup (VEC_cleanup (symbolp), &collector.symbols);
-
-  collector.unique_syms = htab_create_alloc (1, htab_hash_pointer,
-					     htab_eq_pointer, NULL,
-					     xcalloc, xfree);
+  decode_compound_collector collector;
 
   for (ix = 0; VEC_iterate (symtab_ptr, file_symtabs, ix, elt); ++ix)
     {
       if (elt == NULL)
 	{
 	  iterate_over_all_matching_symtabs (state, class_name, STRUCT_DOMAIN,
-					     collect_one_symbol, &collector,
-					     NULL, 0);
+					     NULL, false, collector);
 	  iterate_over_all_matching_symtabs (state, class_name, VAR_DOMAIN,
-					     collect_one_symbol, &collector,
-					     NULL, 0);
+					     NULL, false, collector);
 	}
       else
 	{
@@ -2916,15 +2884,12 @@ lookup_prefix_sym (struct linespec_state *state, VEC (symtab_ptr) *file_symtabs,
 	     been filtered out earlier.  */
 	  gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
 	  set_current_program_space (SYMTAB_PSPACE (elt));
-	  iterate_over_file_blocks (elt, class_name, STRUCT_DOMAIN,
-				    collect_one_symbol, &collector);
-	  iterate_over_file_blocks (elt, class_name, VAR_DOMAIN,
-				    collect_one_symbol, &collector);
+	  iterate_over_file_blocks (elt, class_name, STRUCT_DOMAIN, collector);
+	  iterate_over_file_blocks (elt, class_name, VAR_DOMAIN, collector);
 	}
     }
 
-  discard_cleanups (outer);
-  return collector.symbols;
+  return collector.release_symbols ();
 }
 
 /* A qsort comparison function for symbols.  The resulting order does
@@ -3130,45 +3095,57 @@ find_method (struct linespec_state *self, VEC (symtab_ptr) *file_symtabs,
 
 
 
-/* This object is used when collecting all matching symtabs.  */
+/* This function object is a callback for iterate_over_symtabs, used
+   when collecting all matching symtabs.  */
 
-struct symtab_collector
+class symtab_collector
 {
-  /* The result vector of symtabs.  */
-  VEC (symtab_ptr) *symtabs;
-
-  /* This is used to ensure the symtabs are unique.  */
-  htab_t symtab_table;
-
+public:
   symtab_collector ()
-  : symtabs (NULL),
-    symtab_table (NULL)
   {
+    m_symtabs = NULL;
+    m_symtab_table = htab_create (1, htab_hash_pointer, htab_eq_pointer,
+				  NULL);
   }
 
   ~symtab_collector ()
   {
-    if (symtab_table != NULL)
-      htab_delete (symtab_table);
+    if (m_symtab_table != NULL)
+      htab_delete (m_symtab_table);
   }
-};
 
-/* Callback for iterate_over_symtabs.  */
+  /* Callable as a symbol_found_callback_ftype callback.  */
+  bool operator () (symtab *sym);
 
-static int
-add_symtabs_to_list (struct symtab *symtab, void *d)
+  /* Releases ownership of the collected symtabs and returns them.  */
+  VEC (symtab_ptr) *release_symtabs ()
+  {
+    VEC (symtab_ptr) *res = m_symtabs;
+    m_symtabs = NULL;
+    return res;
+  }
+
+private:
+  /* The result vector of symtabs.  */
+  VEC (symtab_ptr) *m_symtabs;
+
+  /* This is used to ensure the symtabs are unique.  */
+  htab_t m_symtab_table;
+};
+
+bool
+symtab_collector::operator () (struct symtab *symtab)
 {
-  struct symtab_collector *data = (struct symtab_collector *) d;
   void **slot;
 
-  slot = htab_find_slot (data->symtab_table, symtab, INSERT);
+  slot = htab_find_slot (m_symtab_table, symtab, INSERT);
   if (!*slot)
     {
       *slot = symtab;
-      VEC_safe_push (symtab_ptr, data->symtabs, symtab);
+      VEC_safe_push (symtab_ptr, m_symtabs, symtab);
     }
 
-  return 0;
+  return false;
 }
 
 /* Given a file name, return a VEC of all matching symtabs.  If
@@ -3179,33 +3156,29 @@ static VEC (symtab_ptr) *
 collect_symtabs_from_filename (const char *file,
 			       struct program_space *search_pspace)
 {
-  struct symtab_collector collector;
-  struct cleanup *cleanups;
-  struct program_space *pspace;
-
-  collector.symtabs = NULL;
-  collector.symtab_table = htab_create (1, htab_hash_pointer, htab_eq_pointer,
-					NULL);
+  symtab_collector collector;
 
   /* Find that file's data.  */
   if (search_pspace == NULL)
     {
+      struct program_space *pspace;
+
       ALL_PSPACES (pspace)
         {
 	  if (pspace->executing_startup)
 	    continue;
 
 	  set_current_program_space (pspace);
-	  iterate_over_symtabs (file, add_symtabs_to_list, &collector);
+	  iterate_over_symtabs (file, collector);
 	}
     }
   else
     {
       set_current_program_space (search_pspace);
-      iterate_over_symtabs (file, add_symtabs_to_list, &collector);
+      iterate_over_symtabs (file, collector);
     }
 
-  return collector.symtabs;
+  return collector.release_symtabs ();
 }
 
 /* Return all the symtabs associated to the FILENAME.  If SEARCH_PSPACE is
@@ -3577,20 +3550,6 @@ linespec_parse_variable (struct linespec_state *self, const char *variable)
 }
 
 
-/* A callback used to possibly add a symbol to the results.  */
-
-static int
-collect_symbols (struct symbol *sym, void *data)
-{
-  struct collect_info *info = (struct collect_info *) data;
-
-  /* In list mode, add all matching symbols, regardless of class.
-     This allows the user to type "list a_global_variable".  */
-  if (SYMBOL_CLASS (sym) == LOC_BLOCK || info->state->list_mode)
-    VEC_safe_push (symbolp, info->result.symbols, sym);
-  return 1; /* Continue iterating.  */
-}
-
 /* We've found a minimal symbol MSYMBOL in OBJFILE to associate with our
    linespec; return the SAL in RESULT.  This function should return SALs
    matching those from find_function_start_sal, otherwise false
@@ -3858,8 +3817,8 @@ add_matching_symbols_to_info (const char *name,
       if (elt == NULL)
 	{
 	  iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
-					     collect_symbols, info,
-					     pspace, 1);
+					     pspace, true, [&] (symbol *sym)
+	    { return info->add_symbol (sym); });
 	  search_minsyms_for_name (info, name, pspace, NULL);
 	}
       else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
@@ -3870,8 +3829,8 @@ add_matching_symbols_to_info (const char *name,
 	     been filtered out earlier.  */
 	  gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
 	  set_current_program_space (SYMTAB_PSPACE (elt));
-	  iterate_over_file_blocks (elt, name, VAR_DOMAIN,
-				    collect_symbols, info);
+	  iterate_over_file_blocks (elt, name, VAR_DOMAIN, [&] (symbol *sym)
+	    { return info->add_symbol (sym); });
 
 	  /* If no new symbols were found in this iteration and this symtab
 	     is in assembler, we might actually be looking for a label for