analyzer: add logging of aliasing

gcc/analyzer/ChangeLog:
	* engine.cc (impl_run_checkers): Pass logger to engine ctor.
	* region-model-manager.cc
	(region_model_manager::region_model_manager): Add logger param and
	use it to initialize m_logger.
	* region-model.cc (engine::engine): New.
	* region-model.h (region_model_manager::region_model_manager):
	Add logger param.
	(region_model_manager::get_logger): New.
	(region_model_manager::m_logger): New field.
	(engine::engine): New.
	* store.cc (store_manager::get_logger): New.
	(store::set_value): Log scope.  Log when marking a cluster as
	unknown due to possible aliasing.
	* store.h (store_manager::get_logger): New decl.

gcc/analyzer/engine.cc

@@ -5329,7 +5329,7 @@ impl_run_checkers (logger *logger)
   FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node)
     node->get_untransformed_body ();
 
-  engine eng;
+  engine eng (logger);
 
   /* Create the supergraph.  */
   supergraph sg (logger);

gcc/analyzer/region-model-manager.cc

@@ -66,8 +66,9 @@ namespace ana {
 
 /* region_model_manager's ctor.  */
 
-region_model_manager::region_model_manager ()
-: m_next_region_id (0),
+region_model_manager::region_model_manager (logger *logger)
+: m_logger (logger),
+  m_next_region_id (0),
   m_root_region (alloc_region_id ()),
   m_stack_region (alloc_region_id (), &m_root_region),
   m_heap_region (alloc_region_id (), &m_root_region),

gcc/analyzer/region-model.cc

@@ -3965,6 +3965,13 @@ rejected_ranges_constraint::dump_to_pp (pretty_printer *pp) const
 
 /* class engine.  */
 
+/* engine's ctor.  */
+
+engine::engine (logger *logger)
+: m_mgr (logger)
+{
+}
+
 /* Dump the managed objects by class to LOGGER, and the per-class totals.  */
 
 void

gcc/analyzer/region-model.h

@@ -240,7 +240,7 @@ namespace ana {
 class region_model_manager
 {
 public:
-  region_model_manager ();
+  region_model_manager (logger *logger = NULL);
   ~region_model_manager ();
 
   /* svalue consolidation.  */
@@ -335,6 +335,8 @@ public:
   void enable_complexity_check (void) { m_check_complexity = true; }
   void disable_complexity_check (void) { m_check_complexity = false; }
 
+  logger *get_logger () const { return m_logger; }
+
 private:
   bool too_complex_p (const complexity &c) const;
   bool reject_if_too_complex (svalue *sval);
@@ -358,6 +360,8 @@ private:
   const svalue *maybe_fold_asm_output_svalue (tree type,
 					      const vec<const svalue *> &inputs);
 
+  logger *m_logger;
+
   unsigned m_next_region_id;
   root_region m_root_region;
   stack_region m_stack_region;
@@ -1080,6 +1084,7 @@ private:
 class engine
 {
 public:
+  engine (logger *logger = NULL);
   region_model_manager *get_model_manager () { return &m_mgr; }
 
   void log_stats (logger *logger) const;

gcc/analyzer/store.cc

@@ -1987,6 +1987,12 @@ binding_cluster::maybe_get_simple_value (store_manager *mgr) const
 
 /* class store_manager.  */
 
+logger *
+store_manager::get_logger () const
+{
+  return m_mgr->get_logger ();
+}
+
 /* binding consolidation.  */
 
 const concrete_binding *
@@ -2353,6 +2359,9 @@ store::set_value (store_manager *mgr, const region *lhs_reg,
 		  const svalue *rhs_sval,
 		  uncertainty_t *uncertainty)
 {
+  logger *logger = mgr->get_logger ();
+  LOG_SCOPE (logger);
+
   remove_overlapping_bindings (mgr, lhs_reg);
 
   rhs_sval = simplify_for_binding (rhs_sval);
@@ -2405,6 +2414,18 @@ store::set_value (store_manager *mgr, const region *lhs_reg,
 	      gcc_unreachable ();
 
 	    case tristate::TS_UNKNOWN:
+	      if (logger)
+		{
+		  pretty_printer *pp = logger->get_printer ();
+		  logger->start_log_line ();
+		  logger->log_partial ("possible aliasing of ");
+		  iter_base_reg->dump_to_pp (pp, true);
+		  logger->log_partial (" when writing SVAL: ");
+		  rhs_sval->dump_to_pp (pp, true);
+		  logger->log_partial (" to LHS_REG: ");
+		  lhs_reg->dump_to_pp (pp, true);
+		  logger->end_log_line ();
+		}
 	      iter_cluster->mark_region_as_unknown (mgr, iter_base_reg,
 						    uncertainty);
 	      break;

gcc/analyzer/store.h

@@ -787,6 +787,8 @@ class store_manager
 public:
   store_manager (region_model_manager *mgr) : m_mgr (mgr) {}
 
+  logger *get_logger () const;
+
   /* binding consolidation.  */
   const concrete_binding *
   get_concrete_binding (bit_offset_t start_bit_offset,