Extend ipa-pure-const pass to propagate malloc attribute.

2017-10-27  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>

	* cgraph.h (set_malloc_flag): Declare.
	* cgraph.c (set_malloc_flag_1): New function.
	(set_malloc_flag): Likewise.
	* ipa-fnsummary.h (ipa_call_summary): Add new field is_return_callee.
	* ipa-fnsummary.c (ipa_call_summary::reset): Set is_return_callee to
	false.
	(read_ipa_call_summary): Add support for reading is_return_callee.
	(write_ipa_call_summary): Stream is_return_callee.
	* ipa-inline.c (ipa_inline): Remove call to ipa_free_fn_summary.
	* ipa-pure-const.c: Add headers ssa.h, alloc-pool.h, symbol-summary.h,
	ipa-prop.h, ipa-fnsummary.h.
	(pure_const_names): Change to static.
	(malloc_state_e): Define.
	(malloc_state_names): Define.
	(funct_state_d): Add field malloc_state.
	(varying_state): Set malloc_state to STATE_MALLOC_BOTTOM.
	(check_retval_uses): New function.
	(malloc_candidate_p): Likewise.
	(analyze_function): Add support for malloc attribute.
	(pure_const_write_summary): Stream malloc_state.
	(pure_const_read_summary): Add support for reading malloc_state.
	(dump_malloc_lattice): New function.
	(propagate_malloc): New function.
	(warn_function_malloc): New function.
	(ipa_pure_const::execute): Call propagate_malloc and
	ipa_free_fn_summary.
	(pass_local_pure_const::execute): Add support for malloc attribute.
	* ssa-iterators.h (RETURN_FROM_IMM_USE_STMT): New macro.
	* doc/invoke.texi: Document Wsuggest-attribute=malloc.

testsuite/
	* gcc.dg/ipa/propmalloc-1.c: New test-case.
	* gcc.dg/ipa/propmalloc-2.c: Likewise.
	* gcc.dg/ipa/propmalloc-3.c: Likewise.

From-SVN: r254140

1 files changed, 47 insertions, 0 deletions

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d8da3dd..b79f9e8 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -2530,6 +2530,53 @@ cgraph_node::set_nothrow_flag (bool nothrow)
   return changed;
 }
 
+/* Worker to set malloc flag.  */
+static void
+set_malloc_flag_1 (cgraph_node *node, bool malloc_p, bool *changed)
+{
+  if (malloc_p && !DECL_IS_MALLOC (node->decl))
+    {
+      DECL_IS_MALLOC (node->decl) = true;
+      *changed = true;
+    }
+
+  ipa_ref *ref;
+  FOR_EACH_ALIAS (node, ref)
+    {
+      cgraph_node *alias = dyn_cast<cgraph_node *> (ref->referring);
+      if (!malloc_p || alias->get_availability () > AVAIL_INTERPOSABLE)
+	set_malloc_flag_1 (alias, malloc_p, changed);
+    }
+
+  for (cgraph_edge *e = node->callers; e; e = e->next_caller)
+    if (e->caller->thunk.thunk_p
+	&& (!malloc_p || e->caller->get_availability () > AVAIL_INTERPOSABLE))
+      set_malloc_flag_1 (e->caller, malloc_p, changed);
+}
+
+/* Set DECL_IS_MALLOC on NODE's decl and on NODE's aliases if any.  */
+
+bool
+cgraph_node::set_malloc_flag (bool malloc_p)
+{
+  bool changed = false;
+
+  if (!malloc_p || get_availability () > AVAIL_INTERPOSABLE)
+    set_malloc_flag_1 (this, malloc_p, &changed);
+  else
+    {
+      ipa_ref *ref;
+
+      FOR_EACH_ALIAS (this, ref)
+	{
+	  cgraph_node *alias = dyn_cast<cgraph_node *> (ref->referring);
+	  if (!malloc_p || alias->get_availability () > AVAIL_INTERPOSABLE)
+	    set_malloc_flag_1 (alias, malloc_p, &changed);
+	}
+    }
+  return changed;
+}
+
 /* Worker to set_const_flag.  */
 
 static void