From: Jason Merrill <jason@redhat.com>
Date: Sun, 19 Jan 2025 10:15:01 +0000 (-0500)
Subject: c++: vec_safe_reserve usage tweaks
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53d4e355db18fec21515d055924df8290ef5ce14;p=thirdparty%2Fgcc.git

c++: vec_safe_reserve usage tweaks

A couple of cleanups from noticing that the semantics of
std::vector<T>::reserve() (request the new minimum allocation) differ from
the GCC vec<...>::reserve() (request a minimum number of slots available).

In preserve_state, we were tripling the size of the vec when doubling it is
more than enough.

In get_tinfo_desc we were using vec_safe_reserve properly, but it's
simpler to use vec_safe_grow_cleared.

gcc/cp/ChangeLog:

	* name-lookup.cc (name_lookup::preserve_state): Fix reserve call.
	* rtti.cc (get_tinfo_desc): Use vec_safe_grow_cleared.
---

diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 1cd982e12d4..498126a191a 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -583,7 +583,7 @@ name_lookup::preserve_state ()
   if (previous)
     {
       unsigned length = vec_safe_length (previous->scopes);
-      vec_safe_reserve (previous->scopes, length * 2);
+      vec_safe_reserve (previous->scopes, length);
       for (unsigned ix = length; ix--;)
 	{
 	  tree decl = (*previous->scopes)[ix];
diff --git a/gcc/cp/rtti.cc b/gcc/cp/rtti.cc
index 353996206f5..18bc479dc50 100644
--- a/gcc/cp/rtti.cc
+++ b/gcc/cp/rtti.cc
@@ -1318,18 +1318,9 @@ get_pseudo_ti_index (tree type)
 static tinfo_s *
 get_tinfo_desc (unsigned ix)
 {
-  unsigned len = tinfo_descs->length ();
-
-  if (len <= ix)
-    {
-      /* too short, extend.  */
-      len = ix + 1 - len;
-      vec_safe_reserve (tinfo_descs, len);
-      tinfo_s elt;
-      elt.type = elt.vtable = elt.name = NULL_TREE;
-      while (len--)
-	tinfo_descs->quick_push (elt);
-    }
+  if (tinfo_descs->length () <= ix)
+    /* too short, extend.  */
+    vec_safe_grow_cleared (tinfo_descs, ix + 1);
 
   tinfo_s *res = &(*tinfo_descs)[ix];