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List:       gcc-patches
Subject:    [PATCH] c++: Fix ICEs with OBJ_TYPE_REF pretty printing [PR101597]
From:       Jakub Jelinek via Gcc-patches <gcc-patches () gcc ! gnu ! org>
Date:       2021-12-31 9:13:31
Message-ID: 20211231091331.GD2646553 () tucnak
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Hi!

The following testcase ICEs, because middle-end uses the C++ FE pretty
printing code through langhooks in the diagnostics.
The FE expects OBJ_TYPE_REF_OBJECT's type to be useful (pointer to the
class type it is called on), but in the middle-end conversions between
pointer types are useless, so the actual type can be some random
unrelated pointer type (in the testcase void * pointer).  The pretty
printing code then ICEs on it.

The following patch fixes that by sticking the original
OBJ_TYPE_REF_OBJECT's also as type of OBJ_TYPE_REF_TOKEN operand.
That one must be an INTEGER_CST, all the current uses of
OBJ_TYPE_REF_TOKEN just use tree_to_uhwi or tree_to_shwi on it,
and because it is constant, there is no risk of the middle-end propagating
into it some other pointer type.  So, approach similar to how MEM_REF
treats its second operand or a couple of internal functions (e.g.
IFN_VA_ARG) some of its parameters.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2021-12-30  Jakub Jelinek  <jakub@redhat.com>

	PR c++/101597
gcc/cp/
	* class.c (build_vfn_ref): Build OBJ_TYPE_REF with INTEGER_CST
	OBJ_TYPE_REF_TOKEN with type equal to OBJ_TYPE_REF_OBJECT type.
	* error.c (resolve_virtual_fun_from_obj_type_ref): Use type of
	OBJ_TYPE_REF_TOKEN rather than type of OBJ_TYPE_REF_OBJECT as
	obj_type.
gcc/objc/
	* objc-act.c (objc_rewrite_function_call): Build OBJ_TYPE_REF
	with INTEGER_CST OBJ_TYPE_REF_TOKEN with type equal to
	OBJ_TYPE_REF_OBJECT type.
	* objc-next-runtime-abi-01.c (build_objc_method_call): Likewise.
	* objc-gnu-runtime-abi-01.c (build_objc_method_call): Likewise.
	* objc-next-runtime-abi-02.c (build_v2_objc_method_fixup_call,
	build_v2_build_objc_method_call): Likewise.
gcc/testsuite/
	* g++.dg/opt/pr101597.C: New test.

--- gcc/cp/class.c.jj	2021-12-30 15:12:42.706157630 +0100
+++ gcc/cp/class.c	2021-12-30 17:16:23.567589120 +0100
@@ -778,7 +778,8 @@ build_vfn_ref (tree instance_ptr, tree i
 		   cp_build_addr_expr (aref, tf_warning_or_error));
 
   /* Remember this as a method reference, for later devirtualization.  */
-  aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
+  aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr,
+		 fold_convert (TREE_TYPE (instance_ptr), idx));
 
   return aref;
 }
--- gcc/cp/error.c.jj	2021-12-30 15:12:42.714157519 +0100
+++ gcc/cp/error.c	2021-12-30 17:16:23.568589106 +0100
@@ -2149,7 +2149,7 @@ dump_expr_init_vec (cxx_pretty_printer *
 static tree
 resolve_virtual_fun_from_obj_type_ref (tree ref)
 {
-  tree obj_type = TREE_TYPE (OBJ_TYPE_REF_OBJECT (ref));
+  tree obj_type = TREE_TYPE (OBJ_TYPE_REF_TOKEN (ref));
   HOST_WIDE_INT index = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (ref));
   tree fun = BINFO_VIRTUALS (TYPE_BINFO (TREE_TYPE (obj_type)));
   while (index)
--- gcc/objc/objc-act.c.jj	2021-12-30 15:12:43.159151319 +0100
+++ gcc/objc/objc-act.c	2021-12-30 17:16:23.569589092 +0100
@@ -9644,11 +9644,9 @@ objc_rewrite_function_call (tree functio
       && TREE_CODE (TREE_OPERAND (function, 0)) == ADDR_EXPR
       && TREE_CODE (TREE_OPERAND (TREE_OPERAND (function, 0), 0))
 	 == FUNCTION_DECL)
-    {
-      function = build3 (OBJ_TYPE_REF, TREE_TYPE (function),
-			 TREE_OPERAND (function, 0),
-			 first_param, size_zero_node);
-    }
+    function = build3 (OBJ_TYPE_REF, TREE_TYPE (function),
+		       TREE_OPERAND (function, 0), first_param,
+		       build_int_cst (TREE_TYPE (first_param), 0));
 
   return function;
 }
--- gcc/objc/objc-next-runtime-abi-01.c.jj	2021-12-30 15:12:43.159151319 +0100
+++ gcc/objc/objc-next-runtime-abi-01.c	2021-12-30 17:16:23.569589092 +0100
@@ -883,7 +883,7 @@ build_objc_method_call (location_t loc,
 
   /* Build an obj_type_ref, with the correct cast for the method call.  */
   t = build3 (OBJ_TYPE_REF, sender_cast, method,
-			    lookup_object, size_zero_node);
+	      lookup_object, build_int_cst (TREE_TYPE (lookup_object), 0));
   t = build_function_call_vec (loc, vNULL, t, parms, NULL);
   vec_free (parms);
   return t;
--- gcc/objc/objc-gnu-runtime-abi-01.c.jj	2021-12-30 14:16:42.837908238 +0100
+++ gcc/objc/objc-gnu-runtime-abi-01.c	2021-12-30 17:16:23.569589092 +0100
@@ -725,7 +725,8 @@ build_objc_method_call (location_t loc,
       parms->quick_push (TREE_VALUE (method_params));
 
   /* Build an obj_type_ref, with the correct cast for the method call.  */
-  t = build3 (OBJ_TYPE_REF, sender_cast, method, lookup_object, size_zero_node);
+  t = build3 (OBJ_TYPE_REF, sender_cast, method, lookup_object,
+	      build_int_cst (TREE_TYPE (lookup_object), 0));
   t = build_function_call_vec (loc, vNULL, t, parms, NULL);
   vec_free (parms);
   return t;
--- gcc/objc/objc-next-runtime-abi-02.c.jj	2021-12-30 15:12:43.159151319 +0100
+++ gcc/objc/objc-next-runtime-abi-02.c	2021-12-30 17:16:23.570589078 +0100
@@ -1663,7 +1663,8 @@ build_v2_objc_method_fixup_call (int sup
   method_params = tree_cons (NULL_TREE, lookup_object,
                              tree_cons (NULL_TREE, selector,
                                         method_params));
-  t = build3 (OBJ_TYPE_REF, sender_cast, sender, lookup_object, size_zero_node);
+  t = build3 (OBJ_TYPE_REF, sender_cast, sender, lookup_object,
+	      build_int_cst (TREE_TYPE (lookup_object), 0));
   ret_val =  build_function_call (input_location, t, method_params);
   if (check_for_nil)
     {
@@ -1772,7 +1773,7 @@ build_v2_build_objc_method_call (int sup
 
   /* Build an obj_type_ref, with the correct cast for the method call.  */
   t = build3 (OBJ_TYPE_REF, sender_cast, method,
-			    lookup_object, size_zero_node);
+	      lookup_object, build_int_cst (TREE_TYPE (lookup_object), 0));
   tree ret_val = build_function_call_vec (loc, vNULL, t, parms, NULL);
   vec_free (parms);
   if (check_for_nil)
--- gcc/testsuite/g++.dg/opt/pr101597.C.jj	2021-12-30 17:10:59.606117614 +0100
+++ gcc/testsuite/g++.dg/opt/pr101597.C	2021-12-30 17:10:33.856477558 +0100
@@ -0,0 +1,13 @@
+// PR c++/101597
+// { dg-do compile }
+// { dg-options "-O2 -Warray-bounds" }
+
+typedef __SIZE_TYPE__ size_t;
+struct S { virtual void *foo (size_t) __attribute__((alloc_size (2))); };
+
+int
+foo (void *p)
+{
+  char *q = static_cast<char *> (static_cast<S *> (p)->foo (32));
+  return q[64];		// { dg-warning "array subscript 64 is outside array bounds of" }
+}

	Jakub

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