Re: [PATCH] c++: Fix ICEs with OBJ_TYPE_REF pretty printing [PR101597]

Jason Merrill via Gcc-patches Tue, 11 Jan 2022 08:57:34 -0800

On 12/31/21 04:13, Jakub Jelinek wrote:

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?

This new expectation needs to be documented in tree.def. OK with thatchange.

2021-12-30  Jakub Jelinek  <ja...@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

Re: [PATCH] c++: Fix ICEs with OBJ_TYPE_REF pretty printing [PR101597]

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