[PATCH] Factor out the common code in lookup_{static,global}_symbol

[Simon Marchi]

On 2019-08-26 2:29 p.m., Christian Biesinger via gdb-patches wrote:
> The two functions are extremely similar; this factors out their code into
> a shared _internal function.
> 
> gdb/ChangeLog:
> 
> 2019-08-02  Christian Biesinger  <cbiesinger@google.com>
> 
> 	* symtab.c (lookup_static_symbol): Call the new function (and move
> 	it down to be next to lookup_global_symbol).
> 	(struct global_sym_lookup_data): Add block_enum member and rename to...
> 	(struct global_or_static_sym_lookup_data): ...this.
> 	(lookup_symbol_global_iterator_cb): Pass block_index instead of
> 	GLOBAL_BLOCK to lookup_symbol_in_objfile and rename to...
> 	(lookup_symbol_global_or_static_iterator_cb): ...this.
> 	(lookup_global_or_static_symbol): New function.
> 	(lookup_global_symbol): Call new function.
> ---
>  gdb/symtab.c | 96 +++++++++++++++++++++++-----------------------------
>  1 file changed, 42 insertions(+), 54 deletions(-)
> 
> diff --git a/gdb/symtab.c b/gdb/symtab.c
> index d85c77b4ce..5ad6456e03 100644
> --- a/gdb/symtab.c
> +++ b/gdb/symtab.c
> @@ -2566,47 +2566,9 @@ lookup_symbol_in_objfile (struct objfile *objfile, enum block_enum block_index,
>    return result;
>  }
>  
> -/* See symtab.h.  */
> -
> -struct block_symbol
> -lookup_static_symbol (const char *name, const domain_enum domain)
> -{
> -  struct symbol_cache *cache = get_symbol_cache (current_program_space);
> -  struct block_symbol result;
> -  struct block_symbol_cache *bsc;
> -  struct symbol_cache_slot *slot;
> -
> -  /* Lookup in STATIC_BLOCK is not current-objfile-dependent, so just pass
> -     NULL for OBJFILE_CONTEXT.  */
> -  result = symbol_cache_lookup (cache, NULL, STATIC_BLOCK, name, domain,
> -				&bsc, &slot);
> -  if (result.symbol != NULL)
> -    {
> -      if (SYMBOL_LOOKUP_FAILED_P (result))
> -	return {};
> -      return result;
> -    }
> -
> -  for (objfile *objfile : current_program_space->objfiles ())
> -    {
> -      result = lookup_symbol_in_objfile (objfile, STATIC_BLOCK, name, domain);
> -      if (result.symbol != NULL)
> -	{
> -	  /* Still pass NULL for OBJFILE_CONTEXT here.  */
> -	  symbol_cache_mark_found (bsc, slot, NULL, result.symbol,
> -				   result.block);
> -	  return result;
> -	}
> -    }
> -
> -  /* Still pass NULL for OBJFILE_CONTEXT here.  */
> -  symbol_cache_mark_not_found (bsc, slot, NULL, name, domain);
> -  return {};
> -}
> -
>  /* Private data to be used with lookup_symbol_global_iterator_cb.  */
>  
> -struct global_sym_lookup_data
> +struct global_or_static_sym_lookup_data
>  {
>    /* The name of the symbol we are searching for.  */
>    const char *name;
> @@ -2614,6 +2576,9 @@ struct global_sym_lookup_data
>    /* The domain to use for our search.  */
>    domain_enum domain;
>  
> +  /* The block index in which to search.  */
> +  enum block_enum block_index;
> +
>    /* The field where the callback should store the symbol if found.
>       It should be initialized to {NULL, NULL} before the search is started.  */
>    struct block_symbol result;
> @@ -2625,16 +2590,16 @@ struct global_sym_lookup_data
>     which in reality is a pointer to struct global_sym_lookup_data.  */
>  
>  static int
> -lookup_symbol_global_iterator_cb (struct objfile *objfile,
> -				  void *cb_data)
> +lookup_symbol_global_or_static_iterator_cb (struct objfile *objfile,
> +					    void *cb_data)
>  {

The comment above this function talks about GLOBAL_BLOCK and global_sym_lookup_data,
so it needs to be updated.

> -  struct global_sym_lookup_data *data =
> -    (struct global_sym_lookup_data *) cb_data;
> +  struct global_or_static_sym_lookup_data *data =
> +    (struct global_or_static_sym_lookup_data *) cb_data;
>  
>    gdb_assert (data->result.symbol == NULL
>  	      && data->result.block == NULL);
>  
> -  data->result = lookup_symbol_in_objfile (objfile, GLOBAL_BLOCK,
> +  data->result = lookup_symbol_in_objfile (objfile, data->block_index,
>  					   data->name, data->domain);
>  
>    /* If we found a match, tell the iterator to stop.  Otherwise,
> @@ -2642,25 +2607,28 @@ lookup_symbol_global_iterator_cb (struct objfile *objfile,
>    return (data->result.symbol != NULL);
>  }
>  
> -/* See symtab.h.  */
> +/* This function contains the common code of lookup_{global,static}_symbol.
> +   BLOCK is only used if BLOCK_INDEX is GLOBAL_SCOPE, in which case it is
> +   used to retrieve the objfile to start the lookup in.  */

This comment needs to be updated to match the code.

LGTM with those fixed.

Thanks,

Simon