[Patch, PR 57805] Wasted work in write_roots()

[pchang9]

Hi,

The problem appears in revision 200945 in version 4.9.  I attached
a one-line patch that fixes it.  I also reported this problem at
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57805.

In method "write_roots()" in gcc/gengtype.c, the loop on line 4682 should
break immediately after "skip_p" is set to "1". All the iterations after
"skip_p" set to "1" do not perform any useful work, at best they just set
"skip_p" again to "1".

Suggested patch:

Index: gcc/gengtype.c
===================================================================
--- gcc/gengtype.c      (revision 200945)
+++ gcc/gengtype.c      (working copy)
@@ -4682,7 +4682,10 @@
       for (o = v->opt; o; o = o->next)
        if (strcmp (o->name, "deletable") == 0
            || strcmp (o->name, "if_marked") == 0)
-         skip_p = 1;
+         {
+           skip_p = 1;
+           break;
+         }

       if (skip_p)
        continue;

-Chang
Index: gcc/gengtype.c
===================================================================
--- gcc/gengtype.c      (revision 200945)
+++ gcc/gengtype.c      (working copy)
@@ -4682,7 +4682,10 @@
       for (o = v->opt; o; o = o->next)
        if (strcmp (o->name, "deletable") == 0
            || strcmp (o->name, "if_marked") == 0)
-         skip_p = 1;
+         {
+           skip_p = 1;
+           break;
+         }
 
       if (skip_p)
        continue;