[patch +const 2/2] Unify lookup_symbol_in_objfile_symtabs

[patch +const 2/2] Unify lookup_symbol_in_objfile_symtabs

[Jan Kratochvil]

2014-12-03  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* symtab.c (lookup_symbol_in_objfile_symtabs): New declaration.
	(lookup_global_symbol_from_objfile): Call it.

diff --git a/gdb/symtab.c b/gdb/symtab.c
index 79035f6..1951c97 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -79,6 +79,11 @@ struct symbol *lookup_local_symbol (const char *name,
 				    const domain_enum domain,
 				    enum language language);
 
+static struct symbol *
+  lookup_symbol_in_objfile_symtabs (const struct objfile *objfile,
+				    int block_index, const char *name,
+				    const domain_enum domain);
+
 static
 struct symbol *lookup_symbol_via_quick_fns (struct objfile *objfile,
 					    int block_index,
@@ -1546,24 +1551,12 @@ lookup_global_symbol_from_objfile (const struct objfile *main_objfile,
        objfile;
        objfile = objfile_separate_debug_iterate (main_objfile, objfile))
     {
-      struct compunit_symtab *cust;
       struct symbol *sym;
-
-      /* Go through symtabs.  */
-      ALL_OBJFILE_COMPUNITS (objfile, cust)
-	{
-	  const struct blockvector *bv;
-	  const struct block *block;
-
-	  bv = COMPUNIT_BLOCKVECTOR (cust);
-	  block = BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK);
-	  sym = block_lookup_symbol (block, name, domain);
-	  if (sym)
-	    {
-	      block_found = block;
-	      return fixup_symbol_section (sym, objfile);
-	    }
-	}
+      
+      sym = lookup_symbol_in_objfile_symtabs (objfile, GLOBAL_BLOCK, name,
+					      domain);
+      if (sym != NULL)
+	return sym;
 
       sym = lookup_symbol_via_quick_fns ((struct objfile *) objfile,
 					 GLOBAL_BLOCK, name, domain);

Re: [patch +const 2/2] Unify lookup_symbol_in_objfile_symtabs

[Yao Qi]

Jan Kratochvil <jan.kratochvil@redhat.com> writes:

> -	  sym = block_lookup_symbol (block, name, domain);

We are using 'block_lookup_symbol' here...

> -	  if (sym)
> -	    {
> -	      block_found = block;
> -	      return fixup_symbol_section (sym, objfile);
> -	    }
> -	}
> +      
> +      sym = lookup_symbol_in_objfile_symtabs (objfile, GLOBAL_BLOCK, name,
> +					      domain);

... but lookup_symbol_in_objfile_symtabs calls
'block_lookup_symbol_primary'.  Is it because we are iterating COMPUNITS
(primary symtab?) so block_lookup_symbol is equivalent to
block_lookup_symbol_primary under this context?

-- 
Yao (齐尧)

Re: [patch +const 2/2] Unify lookup_symbol_in_objfile_symtabs

[Jan Kratochvil]

On Fri, 05 Dec 2014 13:37:20 +0100, Yao Qi wrote:
> Jan Kratochvil <jan.kratochvil@redhat.com> writes:
> 
> > -	  sym = block_lookup_symbol (block, name, domain);
> 
> We are using 'block_lookup_symbol' here...
> 
> > -	  if (sym)
> > -	    {
> > -	      block_found = block;
> > -	      return fixup_symbol_section (sym, objfile);
> > -	    }
> > -	}
> > +      
> > +      sym = lookup_symbol_in_objfile_symtabs (objfile, GLOBAL_BLOCK, name,
> > +					      domain);
> 
> ... but lookup_symbol_in_objfile_symtabs calls
> 'block_lookup_symbol_primary'.

It has changed yesterday by:
	commit ba715d7fe49c8a59660fbd571b935b29eb7cfbdb
	Author: Jan Kratochvil <jan.kratochvil@redhat.com>
	    Accelerate lookup_symbol_aux_objfile 85x
	-      sym = block_lookup_symbol (block, name, domain);
	+      sym = block_lookup_symbol_primary (block, name, domain);


> Is it because we are iterating COMPUNITS
> (primary symtab?) so block_lookup_symbol is equivalent to
> block_lookup_symbol_primary under this context?

That's right, block_lookup_symbol_primary()'s additional requirement over
block_lookup_symbol() is:
	Function is useful if one iterates all global/static blocks of an
	objfile.

Which is satisfied both in lookup_symbol_in_objfile_symtabs() and in
lookup_global_symbol_from_objfile() thanks to their's ALL_OBJFILE_COMPUNITS.

In fact after reverting that ba715d7fe49c8a59660fbd571b935b29eb7cfbdb above
the lines of code were exactly the same.

So instead of accelerating both lookup_symbol_in_objfile_symtabs() and
lookup_global_symbol_from_objfile() I just accelerated
lookup_symbol_in_objfile_symtabs() and I am proposing to reuse
lookup_symbol_in_objfile_symtabs() in lookup_global_symbol_from_objfile()
instead.  In fact such unification would already save some lines of code even
before the checked-in acceleration patch above.


Thanks,
Jan

Re: [patch +const 2/2] Unify lookup_symbol_in_objfile_symtabs

[Doug Evans]

Jan Kratochvil <jan.kratochvil@redhat.com> writes:
> 2014-12-03  Jan Kratochvil  <jan.kratochvil@redhat.com>
>
> 	* symtab.c (lookup_symbol_in_objfile_symtabs): New declaration.
> 	(lookup_global_symbol_from_objfile): Call it.
>
> diff --git a/gdb/symtab.c b/gdb/symtab.c
> index 79035f6..1951c97 100644
> --- a/gdb/symtab.c
> +++ b/gdb/symtab.c
> @@ -79,6 +79,11 @@ struct symbol *lookup_local_symbol (const char *name,
>  				    const domain_enum domain,
>  				    enum language language);
>  
> +static struct symbol *
> +  lookup_symbol_in_objfile_symtabs (const struct objfile *objfile,
> +				    int block_index, const char *name,
> +				    const domain_enum domain);
> +
>  static
>  struct symbol *lookup_symbol_via_quick_fns (struct objfile *objfile,
>  					    int block_index,
> @@ -1546,24 +1551,12 @@ lookup_global_symbol_from_objfile (const struct objfile *main_objfile,
>         objfile;
>         objfile = objfile_separate_debug_iterate (main_objfile, objfile))
>      {
> -      struct compunit_symtab *cust;
>        struct symbol *sym;
> -
> -      /* Go through symtabs.  */
> -      ALL_OBJFILE_COMPUNITS (objfile, cust)
> -	{
> -	  const struct blockvector *bv;
> -	  const struct block *block;
> -
> -	  bv = COMPUNIT_BLOCKVECTOR (cust);
> -	  block = BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK);
> -	  sym = block_lookup_symbol (block, name, domain);
> -	  if (sym)
> -	    {
> -	      block_found = block;
> -	      return fixup_symbol_section (sym, objfile);
> -	    }
> -	}
> +      
> +      sym = lookup_symbol_in_objfile_symtabs (objfile, GLOBAL_BLOCK, name,
> +					      domain);
> +      if (sym != NULL)
> +	return sym;
>  
>        sym = lookup_symbol_via_quick_fns ((struct objfile *) objfile,
>  					 GLOBAL_BLOCK, name, domain);

LGTM.