Optimize lookup_minimal_symbol_text

lookup_minimal_symbol_text always loops over all objfiles, even when
an objfile is passed in as an argument.  This patch changes the
function to loop over the minimal number of objfiles in the latter
situation.

1 files changed, 41 insertions, 28 deletions

diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index 71e22ce..0e24da9 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -623,38 +623,51 @@ lookup_minimal_symbol_text (const char *name, struct objfile *objf)
 
   unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
 
-  for (objfile *objfile : current_program_space->objfiles ())
-    {
-      if (found_symbol.minsym != NULL)
-	break;
+  auto search = [&] (struct objfile *objfile)
+  {
+    for (msymbol = objfile->per_bfd->msymbol_hash[hash];
+	 msymbol != NULL && found_symbol.minsym == NULL;
+	 msymbol = msymbol->hash_next)
+      {
+	if (strcmp (msymbol->linkage_name (), name) == 0 &&
+	    (msymbol->type () == mst_text
+	     || msymbol->type () == mst_text_gnu_ifunc
+	     || msymbol->type () == mst_file_text))
+	  {
+	    switch (msymbol->type ())
+	      {
+	      case mst_file_text:
+		found_file_symbol.minsym = msymbol;
+		found_file_symbol.objfile = objfile;
+		break;
+	      default:
+		found_symbol.minsym = msymbol;
+		found_symbol.objfile = objfile;
+		break;
+	      }
+	  }
+      }
+  };
 
-      if (objf == NULL || objf == objfile
-	  || objf == objfile->separate_debug_objfile_backlink)
+  if (objf == nullptr)
+    {
+      for (objfile *objfile : current_program_space->objfiles ())
 	{
-	  for (msymbol = objfile->per_bfd->msymbol_hash[hash];
-	       msymbol != NULL && found_symbol.minsym == NULL;
-	       msymbol = msymbol->hash_next)
-	    {
-	      if (strcmp (msymbol->linkage_name (), name) == 0 &&
-		  (msymbol->type () == mst_text
-		   || msymbol->type () == mst_text_gnu_ifunc
-		   || msymbol->type () == mst_file_text))
-		{
-		  switch (msymbol->type ())
-		    {
-		    case mst_file_text:
-		      found_file_symbol.minsym = msymbol;
-		      found_file_symbol.objfile = objfile;
-		      break;
-		    default:
-		      found_symbol.minsym = msymbol;
-		      found_symbol.objfile = objfile;
-		      break;
-		    }
-		}
-	    }
+	  if (found_symbol.minsym != NULL)
+	    break;
+	  search (objfile);
 	}
     }
+  else
+    {
+      for (objfile *objfile : objf->separate_debug_objfiles ())
+	{
+	  if (found_symbol.minsym != NULL)
+	    break;
+	  search (objfile);
+	}
+    }
+
   /* External symbols are best.  */
   if (found_symbol.minsym)
     return found_symbol;