[PATCH 01/08] PR jit/63854: Fix leak in tree-ssa-math-opts.c

[David Malcolm]

Running testsuite/jit.dg/test-functions.c under valgrind showed this
leak (amongst others):

400 bytes in 10 blocks are definitely lost in loss record 142 of 181
   at 0x4A0645D: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x5DCDF2F: xrealloc (xmalloc.c:177)
   by 0x53726CE: void va_heap::reserve<gimple_statement_base*>(vec<gimple_statement_base*, va_heap, vl_embed>*&, unsigned int, bool) (vec.h:310)
   by 0x5371BB1: vec<gimple_statement_base*, va_heap, vl_ptr>::reserve(unsigned int, bool) (vec.h:1428)
   by 0x5370F5D: vec<gimple_statement_base*, va_heap, vl_ptr>::safe_push(gimple_statement_base* const&) (vec.h:1537)
   by 0x5523E71: maybe_record_sincos(vec<gimple_statement_base*, va_heap, vl_ptr>*, basic_block_def**, gimple_statement_base*) (tree-ssa-math-opts.c:718)
   by 0x552403E: execute_cse_sincos_1(tree_node*) (tree-ssa-math-opts.c:760)
   by 0x5526224: (anonymous namespace)::pass_cse_sincos::execute(function*) (tree-ssa-math-opts.c:1497)
   by 0x5250095: execute_one_pass(opt_pass*) (passes.c:2311)
   by 0x525030C: execute_pass_list_1(opt_pass*) (passes.c:2363)
   by 0x525033D: execute_pass_list_1(opt_pass*) (passes.c:2364)
   by 0x525037A: execute_pass_list(function*, opt_pass*) (passes.c:2374)

For some reason (which I've filed for myself as PR jit/64020), this
code was bailing out:

  fndecl = mathfn_built_in (type, BUILT_IN_CEXPI);
  if (!fndecl)
    return false;

That exit path is missing a:
  stmts.release ();
and thus is leaking the buffer of stmts on the way out.

Fix it by converting stmts from vec<> to auto_vec<>, to avoid the need to
have handwritten release calls on every exit path.

gcc/ChangeLog:
	PR jit/63854
	* tree-ssa-math-opts.c (execute_cse_sincos_1): Fix a missing
	release of stmts by converting it to an auto_vec.
---
 gcc/tree-ssa-math-opts.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c
index f9c30bf..5e08c7ee 100644
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -740,7 +740,7 @@ execute_cse_sincos_1 (tree name)
   tree fndecl, res, type;
   gimple def_stmt, use_stmt, stmt;
   int seen_cos = 0, seen_sin = 0, seen_cexpi = 0;
-  vec<gimple> stmts = vNULL;
+  auto_vec<gimple> stmts;
   basic_block top_bb = NULL;
   int i;
   bool cfg_changed = false;
@@ -773,10 +773,7 @@ execute_cse_sincos_1 (tree name)
     }
 
   if (seen_cos + seen_sin + seen_cexpi <= 1)
-    {
-      stmts.release ();
-      return false;
-    }
+    return false;
 
   /* Simply insert cexpi at the beginning of top_bb but not earlier than
      the name def statement.  */
@@ -835,8 +832,6 @@ execute_cse_sincos_1 (tree name)
 	  cfg_changed = true;
     }
 
-  stmts.release ();
-
   return cfg_changed;
 }
 
-- 
1.8.5.3