Re: [PATCH 1/4] Use new for ada_symbol_cache

[Andrew Burgess <andrew.burgess@embecosm.com>]

* Tom Tromey <tromey@adacore.com> [2021-02-18 11:04:27 -0700]:

> This changes the ada_symbol_cache to be allocated with 'new' and
> managed via unique_ptr.  This simplifies the code somewhat.  Also,
> ada_clear_symbol_cache is changed so that it does not allocate a
> symbol cache just to clear it.
> 
> gdb/ChangeLog
> 2021-02-18  Tom Tromey  <tromey@adacore.com>
> 
> 	* ada-lang.c (struct ada_symbol_cache) <cache_space>: Now an
> 	auto_obstack.
> 	<root>: Initialize.
> 	(ada_pspace_data): Remove destructor.
> 	<sym_cache>: Now a unique_ptr.
> 	(ada_init_symbol_cache, ada_free_symbol_cache): Remove.
> 	(ada_get_symbol_cache): Use 'new'.
> 	(ada_clear_symbol_cache): Rewrite.

LGTM.

Thanks,
Andrew

> ---
>  gdb/ChangeLog  | 11 +++++++++++
>  gdb/ada-lang.c | 51 +++++++++++---------------------------------------
>  2 files changed, 22 insertions(+), 40 deletions(-)
> 
> diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
> index 416a45be58e..e2b2e6105b0 100644
> --- a/gdb/ada-lang.c
> +++ b/gdb/ada-lang.c
> @@ -283,14 +283,12 @@ struct cache_entry
>  struct ada_symbol_cache
>  {
>    /* An obstack used to store the entries in our cache.  */
> -  struct obstack cache_space;
> +  struct auto_obstack cache_space;
>  
>    /* The root of the hash table used to implement our symbol cache.  */
> -  struct cache_entry *root[HASH_SIZE];
> +  struct cache_entry *root[HASH_SIZE] {};
>  };
>  
> -static void ada_free_symbol_cache (struct ada_symbol_cache *sym_cache);
> -
>  /* Maximum-sized dynamic type.  */
>  static unsigned int varsize_limit;
>  
> @@ -385,14 +383,8 @@ ada_inferior_exit (struct inferior *inf)
>  /* This module's per-program-space data.  */
>  struct ada_pspace_data
>  {
> -  ~ada_pspace_data ()
> -  {
> -    if (sym_cache != NULL)
> -      ada_free_symbol_cache (sym_cache);
> -  }
> -
>    /* The Ada symbol cache.  */
> -  struct ada_symbol_cache *sym_cache = nullptr;
> +  std::unique_ptr<ada_symbol_cache> sym_cache;
>  };
>  
>  /* Key to our per-program-space data.  */
> @@ -4604,24 +4596,6 @@ make_array_descriptor (struct type *type, struct value *arr)
>     even in this case, some expensive name-based symbol searches are still
>     sometimes necessary - to find an XVZ variable, mostly.  */
>  
> -/* Initialize the contents of SYM_CACHE.  */
> -
> -static void
> -ada_init_symbol_cache (struct ada_symbol_cache *sym_cache)
> -{
> -  obstack_init (&sym_cache->cache_space);
> -  memset (sym_cache->root, '\000', sizeof (sym_cache->root));
> -}
> -
> -/* Free the memory used by SYM_CACHE.  */
> -
> -static void
> -ada_free_symbol_cache (struct ada_symbol_cache *sym_cache)
> -{
> -  obstack_free (&sym_cache->cache_space, NULL);
> -  xfree (sym_cache);
> -}
> -
>  /* Return the symbol cache associated to the given program space PSPACE.
>     If not allocated for this PSPACE yet, allocate and initialize one.  */
>  
> @@ -4630,25 +4604,22 @@ ada_get_symbol_cache (struct program_space *pspace)
>  {
>    struct ada_pspace_data *pspace_data = get_ada_pspace_data (pspace);
>  
> -  if (pspace_data->sym_cache == NULL)
> -    {
> -      pspace_data->sym_cache = XCNEW (struct ada_symbol_cache);
> -      ada_init_symbol_cache (pspace_data->sym_cache);
> -    }
> +  if (pspace_data->sym_cache == nullptr)
> +    pspace_data->sym_cache.reset (new ada_symbol_cache);
>  
> -  return pspace_data->sym_cache;
> +  return pspace_data->sym_cache.get ();
>  }
>  
>  /* Clear all entries from the symbol cache.  */
>  
>  static void
> -ada_clear_symbol_cache (void)
> +ada_clear_symbol_cache ()
>  {
> -  struct ada_symbol_cache *sym_cache
> -    = ada_get_symbol_cache (current_program_space);
> +  struct ada_pspace_data *pspace_data
> +    = get_ada_pspace_data (current_program_space);
>  
> -  obstack_free (&sym_cache->cache_space, NULL);
> -  ada_init_symbol_cache (sym_cache);
> +  if (pspace_data->sym_cache != nullptr)
> +    pspace_data->sym_cache.reset ();
>  }
>  
>  /* Search our cache for an entry matching NAME and DOMAIN.
> -- 
> 2.26.2
>