On 5/9/24 14:46, Jakub Jelinek wrote:
On Thu, May 09, 2024 at 01:05:59PM -0400, Jason Merrill wrote:
I think I'd rather pass ob_parm to start_cleanup_fn, where it can also
replace the flag_use_cxa_atexit check in that function.

Good idea, changed in the following patch.

@@ -9998,7 +10004,8 @@ register_dtor_fn (tree decl)
       {
         /* We must convert CLEANUP to the type that "__cxa_atexit"
         expects.  */
-      cleanup = build_nop (get_atexit_fn_ptr_type (), cleanup);
+      cleanup = build_nop (ob_parm ? get_cxa_atexit_fn_ptr_type ()
+                                  : get_atexit_fn_ptr_type (), cleanup);

If we're (now) using the correct type to build the cleanup fn, this
conversion should be unnecessary.

This is the use_dtor case, where cleanup will have METHOD_TYPE, so
I think we need to cast.  But, we can cast always to
get_cxa_atexit_fn_ptr_type () type, because this is in use_dtor guarded code
and use_dtor is ob_parm && CLASS_TYPE_P (type), so when use_dtor is true,
ob_parm is also true.

Ok for trunk if it passes another bootstrap/regtest?

OK.

2024-05-09  Jakub Jelinek  <ja...@redhat.com>

        PR target/114968
gcc/
        * target.def (use_atexit_for_cxa_atexit): Remove spurious space
        from comment.
        (adjust_cdtor_callabi_fntype): New cxx target hook.
        * targhooks.h (default_cxx_adjust_cdtor_callabi_fntype): Declare.
        * targhooks.cc (default_cxx_adjust_cdtor_callabi_fntype): New
        function.
        * doc/tm.texi.in (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Add.
        * doc/tm.texi: Regenerate.
        * config/i386/i386.cc (ix86_cxx_adjust_cdtor_callabi_fntype): New
        function.
        (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Redefine.
gcc/cp/
        * cp-tree.h (atexit_fn_ptr_type_node, cleanup_type): Adjust macro
        comments.
        (get_cxa_atexit_fn_ptr_type): Declare.
        * decl.cc (get_atexit_fn_ptr_type): Adjust function comment, only
        build type for atexit argument.
        (get_cxa_atexit_fn_ptr_type): New function.
        (get_atexit_node): Call get_cxa_atexit_fn_ptr_type rather than
        get_atexit_fn_ptr_type when using __cxa_atexit.
        (get_thread_atexit_node): Call get_cxa_atexit_fn_ptr_type
        rather than get_atexit_fn_ptr_type.
        (start_cleanup_fn): Add ob_parm argument, call
        get_cxa_atexit_fn_ptr_type or get_atexit_fn_ptr_type depending
        on it and create PARM_DECL also based on that argument.
        (register_dtor_fn): Adjust start_cleanup_fn caller, use
        get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type
        for use_dtor casts.
        * except.cc (build_throw): Use get_cxa_atexit_fn_ptr_type ().

--- gcc/target.def.jj   2024-05-09 10:30:54.926503473 +0200
+++ gcc/target.def      2024-05-09 20:27:16.294780780 +0200
@@ -6498,7 +6498,7 @@ is in effect.  The default is to return
   hook_bool_void_false)
/* Returns true if target may use atexit in the same manner as
-   __cxa_atexit  to register static destructors.  */
+   __cxa_atexit to register static destructors.  */
  DEFHOOK
  (use_atexit_for_cxa_atexit,
   "This hook returns true if the target @code{atexit} function can be used\n\
@@ -6509,6 +6509,17 @@ unloaded. The default is to return false
   bool, (void),
   hook_bool_void_false)
+/* Returns modified FUNCTION_TYPE for cdtor callabi. */
+DEFHOOK
+(adjust_cdtor_callabi_fntype,
+ "This hook returns a possibly modified @code{FUNCTION_TYPE} for arguments\n\
+to @code{__cxa_atexit}, @code{__cxa_thread_atexit} or @code{__cxa_throw}\n\
+function pointers.  ABIs like mingw32 require special attributes to be added\n\
+to function types pointed to by arguments of these functions.\n\
+The default is to return the passed argument unmodified.",
+ tree, (tree fntype),
+ default_cxx_adjust_cdtor_callabi_fntype)
+
  DEFHOOK
  (adjust_class_at_definition,
  "@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\n\
--- gcc/targhooks.h.jj  2024-05-09 10:30:54.941503269 +0200
+++ gcc/targhooks.h     2024-05-09 20:27:16.315780505 +0200
@@ -65,6 +65,7 @@ extern machine_mode default_mode_for_suf
extern tree default_cxx_guard_type (void);
  extern tree default_cxx_get_cookie_size (tree);
+extern tree default_cxx_adjust_cdtor_callabi_fntype (tree);
extern bool hook_pass_by_reference_must_pass_in_stack
    (cumulative_args_t, const function_arg_info &);
--- gcc/targhooks.cc.jj 2024-05-09 10:30:54.927503459 +0200
+++ gcc/targhooks.cc    2024-05-09 20:27:16.338780204 +0200
@@ -329,6 +329,14 @@ default_cxx_get_cookie_size (tree type)
    return cookie_size;
  }
+/* Returns modified FUNCTION_TYPE for cdtor callabi. */
+
+tree
+default_cxx_adjust_cdtor_callabi_fntype (tree fntype)
+{
+  return fntype;
+}
+
  /* Return true if a parameter must be passed by reference.  This version
     of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
--- gcc/doc/tm.texi.in.jj 2024-05-09 10:30:54.897503866 +0200
+++ gcc/doc/tm.texi.in  2024-05-09 20:27:16.355779981 +0200
@@ -7223,6 +7223,8 @@ floating-point support; they are not inc
@hook TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT +@hook TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE
+
  @hook TARGET_CXX_ADJUST_CLASS_AT_DEFINITION
@hook TARGET_CXX_DECL_MANGLING_CONTEXT
--- gcc/doc/tm.texi.jj  2024-05-09 10:30:54.862504342 +0200
+++ gcc/doc/tm.texi     2024-05-09 20:27:16.368779810 +0200
@@ -11117,6 +11117,14 @@ shared libraries are run in the correct
  unloaded. The default is to return false.
  @end deftypefn
+@deftypefn {Target Hook} tree TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE (tree @var{fntype})
+This hook returns a possibly modified @code{FUNCTION_TYPE} for arguments
+to @code{__cxa_atexit}, @code{__cxa_thread_atexit} or @code{__cxa_throw}
+function pointers.  ABIs like mingw32 require special attributes to be added
+to function types pointed to by arguments of these functions.
+The default is to return the passed argument unmodified.
+@end deftypefn
+
  @deftypefn {Target Hook} void TARGET_CXX_ADJUST_CLASS_AT_DEFINITION (tree 
@var{type})
  @var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just
  been defined.  Use this hook to make adjustments to the class (eg, tweak
--- gcc/config/i386/i386.cc.jj  2024-05-09 10:30:58.508454809 +0200
+++ gcc/config/i386/i386.cc     2024-05-09 20:27:16.392779496 +0200
@@ -25800,6 +25800,20 @@ ix86_bitint_type_info (int n, struct bit
    return true;
  }
+/* Returns modified FUNCTION_TYPE for cdtor callabi. */
+tree
+ix86_cxx_adjust_cdtor_callabi_fntype (tree fntype)
+{
+  if (TARGET_64BIT
+      || TARGET_RTD
+      || ix86_function_type_abi (fntype) != MS_ABI)
+    return fntype;
+  /* For 32-bit MS ABI add thiscall attribute.  */
+  tree attribs = tree_cons (get_identifier ("thiscall"), NULL_TREE,
+                           TYPE_ATTRIBUTES (fntype));
+  return build_type_attribute_variant (fntype, attribs);
+}
+
  /* Implement PUSH_ROUNDING.  On 386, we have pushw instruction that
     decrements by exactly 2 no matter what the position was, there is no pushb.
@@ -26411,6 +26425,8 @@ static const scoped_attribute_specs *con
  #define TARGET_C_EXCESS_PRECISION ix86_get_excess_precision
  #undef TARGET_C_BITINT_TYPE_INFO
  #define TARGET_C_BITINT_TYPE_INFO ix86_bitint_type_info
+#undef TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE
+#define TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE 
ix86_cxx_adjust_cdtor_callabi_fntype
  #undef TARGET_PROMOTE_PROTOTYPES
  #define TARGET_PROMOTE_PROTOTYPES hook_bool_const_tree_true
  #undef TARGET_PUSH_ARGUMENT
--- gcc/cp/cp-tree.h.jj 2024-05-09 20:26:12.619615230 +0200
+++ gcc/cp/cp-tree.h    2024-05-09 20:27:16.395779457 +0200
@@ -368,8 +368,7 @@ extern GTY(()) tree cp_global_trees[CPTI
  #define throw_fn                      cp_global_trees[CPTI_THROW_FN]
  #define rethrow_fn                    cp_global_trees[CPTI_RETHROW_FN]
-/* The type of the function-pointer argument to "__cxa_atexit" (or
-   "std::atexit", if "__cxa_atexit" is not being used).  */
+/* The type of the function-pointer argument to "std::atexit".  */
  #define atexit_fn_ptr_type_node         
cp_global_trees[CPTI_ATEXIT_FN_PTR_TYPE]
/* A pointer to `std::atexit'. */
@@ -384,7 +383,8 @@ extern GTY(()) tree cp_global_trees[CPTI
  /* The declaration of the dynamic_cast runtime.  */
  #define dynamic_cast_node             cp_global_trees[CPTI_DCAST]
-/* The type of a destructor. */
+/* The type of a destructor, passed to __cxa_atexit, __cxa_thread_atexit
+   or __cxa_throw.  */
  #define cleanup_type                  cp_global_trees[CPTI_CLEANUP_TYPE]
/* The type of the vtt parameter passed to subobject constructors and
@@ -7067,6 +7067,7 @@ extern tree check_default_argument                (tre
  extern int wrapup_namespace_globals           ();
  extern tree create_implicit_typedef           (tree, tree);
  extern int local_variable_p                   (const_tree);
+extern tree get_cxa_atexit_fn_ptr_type         ();
  extern tree register_dtor_fn                  (tree);
  extern tmpl_spec_kind current_tmpl_spec_kind  (int);
  extern tree cxx_builtin_function              (tree decl);
--- gcc/cp/decl.cc.jj   2024-05-09 20:26:12.670614561 +0200
+++ gcc/cp/decl.cc      2024-05-09 20:34:08.556378168 +0200
@@ -93,7 +93,7 @@ static void record_key_method_defined (t
  static tree create_array_type_for_decl (tree, tree, tree, location_t);
  static tree get_atexit_node (void);
  static tree get_dso_handle_node (void);
-static tree start_cleanup_fn (void);
+static tree start_cleanup_fn (bool);
  static void end_cleanup_fn (void);
  static tree cp_make_fname_decl (location_t, tree, int);
  static void initialize_predefined_identifiers (void);
@@ -9678,34 +9678,39 @@ declare_global_var (tree name, tree type
    return decl;
  }
-/* Returns the type for the argument to "__cxa_atexit" (or "atexit",
-   if "__cxa_atexit" is not being used) corresponding to the function
+/* Returns the type for the argument to "atexit" corresponding to the function
     to be called when the program exits.  */
static tree
-get_atexit_fn_ptr_type (void)
+get_atexit_fn_ptr_type ()
  {
-  tree fn_type;
-
    if (!atexit_fn_ptr_type_node)
      {
-      tree arg_type;
-      if (flag_use_cxa_atexit
-         && !targetm.cxx.use_atexit_for_cxa_atexit ())
-       /* The parameter to "__cxa_atexit" is "void (*)(void *)".  */
-       arg_type = ptr_type_node;
-      else
-       /* The parameter to "atexit" is "void (*)(void)".  */
-       arg_type = NULL_TREE;
-
-      fn_type = build_function_type_list (void_type_node,
-                                         arg_type, NULL_TREE);
+      tree fn_type = build_function_type_list (void_type_node, NULL_TREE);
        atexit_fn_ptr_type_node = build_pointer_type (fn_type);
      }
return atexit_fn_ptr_type_node;
  }
+/* Returns the type for the argument to "__cxa_atexit", "__cxa_thread_atexit"
+   or "__cxa_throw" corresponding to the destructor to be called when the
+   program exits.  */
+
+tree
+get_cxa_atexit_fn_ptr_type ()
+{
+  if (!cleanup_type)
+    {
+      tree fntype = build_function_type_list (void_type_node,
+                                             ptr_type_node, NULL_TREE);
+      fntype = targetm.cxx.adjust_cdtor_callabi_fntype (fntype);
+      cleanup_type = build_pointer_type (fntype);
+    }
+
+  return cleanup_type;
+}
+
  /* Returns a pointer to the `atexit' function.  Note that if
     FLAG_USE_CXA_ATEXIT is nonzero, then this will actually be the new
     `__cxa_atexit' function specified in the IA64 C++ ABI.  */
@@ -9736,7 +9741,7 @@ get_atexit_node (void)
        use_aeabi_atexit = targetm.cxx.use_aeabi_atexit ();
        /* First, build the pointer-to-function type for the first
         argument.  */
-      fn_ptr_type = get_atexit_fn_ptr_type ();
+      fn_ptr_type = get_cxa_atexit_fn_ptr_type ();
        /* Then, build the rest of the argument types.  */
        argtype2 = ptr_type_node;
        if (use_aeabi_atexit)
@@ -9819,7 +9824,7 @@ get_thread_atexit_node (void)
int __cxa_thread_atexit (void (*)(void *), void *, void *) */
    tree fn_type = build_function_type_list (integer_type_node,
-                                          get_atexit_fn_ptr_type (),
+                                          get_cxa_atexit_fn_ptr_type (),
                                           ptr_type_node, ptr_type_node,
                                           NULL_TREE);
@@ -9861,12 +9866,13 @@ get_dso_handle_node (void)
  }
/* Begin a new function with internal linkage whose job will be simply
-   to destroy some particular variable.  */
+   to destroy some particular variable.  OB_PARM is true if object pointer
+   is passed to the cleanup function, otherwise no argument is passed.  */
static GTY(()) int start_cleanup_cnt; static tree
-start_cleanup_fn (void)
+start_cleanup_fn (bool ob_parm)
  {
    char name[32];
@@ -9877,8 +9883,9 @@ start_cleanup_fn (void) /* Build the name of the function. */
    sprintf (name, "__tcf_%d", start_cleanup_cnt++);
+  tree fntype = TREE_TYPE (ob_parm ? get_cxa_atexit_fn_ptr_type ()
+                                  : get_atexit_fn_ptr_type ());
    /* Build the function declaration.  */
-  tree fntype = TREE_TYPE (get_atexit_fn_ptr_type ());
    tree fndecl = build_lang_decl (FUNCTION_DECL, get_identifier (name), 
fntype);
    DECL_CONTEXT (fndecl) = FROB_CONTEXT (current_namespace);
    /* It's a function with internal linkage, generated by the
@@ -9891,7 +9898,7 @@ start_cleanup_fn (void)
       emissions this way.  */
    DECL_DECLARED_INLINE_P (fndecl) = 1;
    DECL_INTERFACE_KNOWN (fndecl) = 1;
-  if (flag_use_cxa_atexit && !targetm.cxx.use_atexit_for_cxa_atexit ())
+  if (ob_parm)
      {
        /* Build the parameter.  */
        tree parmdecl = cp_build_parm_decl (fndecl, NULL_TREE, ptr_type_node);
@@ -9968,8 +9975,8 @@ register_dtor_fn (tree decl)
        build_cleanup (decl);
/* Now start the function. */
-      cleanup = start_cleanup_fn ();
-
+      cleanup = start_cleanup_fn (ob_parm);
+
        /* Now, recompute the cleanup.  It may contain SAVE_EXPRs that refer
         to the original function, rather than the anonymous one.  That
         will make the back end think that nested functions are in use,
@@ -9998,7 +10005,7 @@ register_dtor_fn (tree decl)
      {
        /* We must convert CLEANUP to the type that "__cxa_atexit"
         expects.  */
-      cleanup = build_nop (get_atexit_fn_ptr_type (), cleanup);
+      cleanup = build_nop (get_cxa_atexit_fn_ptr_type (), cleanup);
        /* "__cxa_atexit" will pass the address of DECL to the
         cleanup function.  */
        mark_used (decl);
--- gcc/cp/except.cc.jj 2024-05-09 10:30:54.821504899 +0200
+++ gcc/cp/except.cc    2024-05-09 20:27:16.412779234 +0200
@@ -645,11 +645,7 @@ build_throw (location_t loc, tree exp, t
/* The CLEANUP_TYPE is the internal type of a destructor. */
        if (!cleanup_type)
-       {
-         tree tmp = build_function_type_list (void_type_node,
-                                              ptr_type_node, NULL_TREE);
-         cleanup_type = build_pointer_type (tmp);
-       }
+       cleanup_type = get_cxa_atexit_fn_ptr_type ();
if (!throw_fn)
        {


        Jakub


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