From 57d1b68d6582efec5a7ca63ea56a1cedbfe6e874 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Wed, 10 Feb 2021 09:39:54 +0100
Subject: [PATCH] if-to-switch: fix memory leak in case merging

gcc/ChangeLog:

	PR tree-optimization/99002
	PR tree-optimization/99026
	* gimple-if-to-switch.cc (if_chain::is_beneficial): Fix memory
	leak when adjacent cases are merged.
	* tree-switch-conversion.c (switch_decision_tree::analyze_switch_statement): Use
	release_clusters.
	(make_pass_lower_switch): Remove trailing whitespace.
	* tree-switch-conversion.h (release_clusters): New.
---
 gcc/gimple-if-to-switch.cc   | 17 +++++++++--------
 gcc/tree-switch-conversion.c |  9 +--------
 gcc/tree-switch-conversion.h | 10 ++++++++++
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/gcc/gimple-if-to-switch.cc b/gcc/gimple-if-to-switch.cc
index f39662be3e6..16fabef7ca0 100644
--- a/gcc/gimple-if-to-switch.cc
+++ b/gcc/gimple-if-to-switch.cc
@@ -227,6 +227,7 @@ if_chain::is_beneficial ()
 			(left->get_high ()), wi::one (TYPE_PRECISION (type))))
 	    {
 	      left->set_high (right->get_high ());
+	      delete right;
 	      continue;
 	    }
 	}
@@ -241,20 +242,20 @@ if_chain::is_beneficial ()
     = jump_table_cluster::find_jump_tables (filtered_clusters);
   bool r = output.length () < filtered_clusters.length ();
   if (r)
-    dump_clusters (&output, "JT can be built");
-  output.release ();
-  if (r)
-    return true;
+    {
+      dump_clusters (&output, "JT can be built");
+      release_clusters (output);
+      return true;
+    }
+  else
+    output.release ();
 
   output = bit_test_cluster::find_bit_tests (filtered_clusters);
   r = output.length () < filtered_clusters.length ();
   if (r)
     dump_clusters (&output, "BT can be built");
 
-  for (unsigned i = 0; i < output.length (); i++)
-    delete output[i];
-
-  output.release ();
+  release_clusters (output);
   return r;
 }
 
diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c
index a4798812dbf..7f65c4ce839 100644
--- a/gcc/tree-switch-conversion.c
+++ b/gcc/tree-switch-conversion.c
@@ -1824,12 +1824,7 @@ switch_decision_tree::analyze_switch_statement ()
   output.release ();
 
   bool expanded = try_switch_expansion (output2);
-
-  for (unsigned i = 0; i < output2.length (); i++)
-    delete output2[i];
-
-  output2.release ();
-
+  release_clusters (output2);
   return expanded;
 }
 
@@ -2597,5 +2592,3 @@ make_pass_lower_switch (gcc::context *ctxt)
 {
   return new pass_lower_switch<false> (ctxt);
 }
-
-
diff --git a/gcc/tree-switch-conversion.h b/gcc/tree-switch-conversion.h
index d3d568e84cc..d76f19b57f6 100644
--- a/gcc/tree-switch-conversion.h
+++ b/gcc/tree-switch-conversion.h
@@ -893,6 +893,16 @@ switch_decision_tree::reset_out_edges_aux (gswitch *swtch)
     e->aux = (void *) 0;
 }
 
+/* Release CLUSTERS vector and destruct all dynamically allocated items.  */
+
+static inline void
+release_clusters (vec<cluster *> &clusters)
+{
+  for (unsigned i = 0; i < clusters.length (); i++)
+    delete clusters[i];
+  clusters.release ();
+}
+
 } // tree_switch_conversion namespace
 
 #endif // TREE_SWITCH_CONVERSION_H
-- 
2.30.2