analyzer: add ctxt to fill_region/zero_fill_region

I noticed that region_model's fill_region/zero_fill_region member
functions weren't checking that the write to the region was valid.

Fixed thusly.

gcc/analyzer/ChangeLog:
	* kf.cc (kf_calloc::impl_call_pre): Pass ctxt to zero_fill_region.
	(kf_memset::impl_call_pre): Move responsibility for calling
	check_region_for_write to fill_region.
	* region-model.cc (region_model::on_assignment): Pass ctxt to
	zero_fill_region.
	(region_model::fill_region): Add "ctxt" param, using it to call
	check_region_for_write.
	(region_model::zero_fill_region): Likewise.
	* region-model.h (region_model::fill_region): Add "ctxt" param.
	(region_model::zero_fill_region): Likewise.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/analyzer_cpython_plugin.c: Pass ctxt to
	zero_fill_region.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

4 files changed, 22 insertions, 13 deletions

diff --git a/gcc/analyzer/kf.cc b/gcc/analyzer/kf.cc
index e5bd745..a622277 100644
--- a/gcc/analyzer/kf.cc
+++ b/gcc/analyzer/kf.cc
@@ -358,7 +358,7 @@ kf_calloc::impl_call_pre (const call_details &cd) const
     = model->get_or_create_region_for_heap_alloc (prod_sval, cd.get_ctxt ());
   const region *sized_reg
     = mgr->get_sized_region (new_reg, NULL_TREE, prod_sval);
-  model->zero_fill_region (sized_reg);
+  model->zero_fill_region (sized_reg, cd.get_ctxt ());
   if (cd.get_lhs_type ())
     {
       const svalue *ptr_sval
@@ -650,10 +650,7 @@ kf_memset::impl_call_pre (const call_details &cd) const
   const region *sized_dest_reg = mgr->get_sized_region (dest_reg,
 							NULL_TREE,
 							num_bytes_sval);
-  model->check_region_for_write (sized_dest_reg,
-				 nullptr,
-				 cd.get_ctxt ());
-  model->fill_region (sized_dest_reg, fill_value_u8);
+  model->fill_region (sized_dest_reg, fill_value_u8, cd.get_ctxt ());
 
   cd.maybe_set_lhs (dest_sval);
 }
diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index 82bc3b2..6be0ad7 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -1204,7 +1204,7 @@ region_model::on_assignment (const gassign *assign, region_model_context *ctxt)
 	    /* Any CONSTRUCTOR that survives to this point is either
 	       just a zero-init of everything, or a vector.  */
 	    if (!CONSTRUCTOR_NO_CLEARING (rhs1))
-	      zero_fill_region (lhs_reg);
+	      zero_fill_region (lhs_reg, ctxt);
 	    unsigned ix;
 	    tree index;
 	    tree val;
@@ -3929,19 +3929,28 @@ region_model::purge_region (const region *reg)
   m_store.purge_region (m_mgr->get_store_manager(), reg);
 }
 
-/* Fill REG with SVAL.  */
+/* Fill REG with SVAL.
+   Use CTXT to report any warnings associated with the write
+   (e.g. out-of-bounds).  */
 
 void
-region_model::fill_region (const region *reg, const svalue *sval)
+region_model::fill_region (const region *reg,
+			   const svalue *sval,
+			   region_model_context *ctxt)
 {
+  check_region_for_write (reg, nullptr, ctxt);
   m_store.fill_region (m_mgr->get_store_manager(), reg, sval);
 }
 
-/* Zero-fill REG.  */
+/* Zero-fill REG.
+   Use CTXT to report any warnings associated with the write
+   (e.g. out-of-bounds).  */
 
 void
-region_model::zero_fill_region (const region *reg)
+region_model::zero_fill_region (const region *reg,
+				region_model_context *ctxt)
 {
+  check_region_for_write (reg, nullptr, ctxt);
   m_store.zero_fill_region (m_mgr->get_store_manager(), reg);
 }
 
diff --git a/gcc/analyzer/region-model.h b/gcc/analyzer/region-model.h
index bb50ff1..625f688 100644
--- a/gcc/analyzer/region-model.h
+++ b/gcc/analyzer/region-model.h
@@ -370,8 +370,11 @@ class region_model
   void set_value (tree lhs, tree rhs, region_model_context *ctxt);
   void clobber_region (const region *reg);
   void purge_region (const region *reg);
-  void fill_region (const region *reg, const svalue *sval);
-  void zero_fill_region (const region *reg);
+  void fill_region (const region *reg,
+		    const svalue *sval,
+		    region_model_context *ctxt);
+  void zero_fill_region (const region *reg,
+			 region_model_context *ctxt);
   void write_bytes (const region *dest_reg,
 		    const svalue *num_bytes_sval,
 		    const svalue *sval,
diff --git a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
index bf1982e..a364c8a 100644
--- a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
+++ b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
@@ -1031,7 +1031,7 @@ kf_PyList_New::impl_call_post (const call_details &cd) const
           const region *ob_item_sized_region
               = model->get_or_create_region_for_heap_alloc (prod_sval,
                                                             cd.get_ctxt ());
-          model->zero_fill_region (ob_item_sized_region);
+          model->zero_fill_region (ob_item_sized_region, cd.get_ctxt ());
           const svalue *ob_item_ptr_sval
               = mgr->get_ptr_svalue (pyobj_ptr_ptr, ob_item_sized_region);
           const svalue *ob_item_unmergeable