re PR ada/37139 (DEP prevents using Ada tasking)

	PR ada/37139
	PR ada/67205
	* common.opt (-ftrampolines): New option.
	* doc/invoke.texi (Code Gen Options): Document it.
	* doc/tm.texi.in (Trampolines): Add TARGET_CUSTOM_FUNCTION_DESCRIPTORS.
	* doc/tm.texi: Regenerate.
	* builtins.def: Add init_descriptor and adjust_descriptor.
	* builtins.c (expand_builtin_init_trampoline): Do not issue a warning
	on platforms with descriptors.
	(expand_builtin_init_descriptor): New function.
	(expand_builtin_adjust_descriptor): Likewise.
	(expand_builtin) <BUILT_IN_INIT_DESCRIPTOR>: New case.
	<BUILT_IN_ADJUST_DESCRIPTOR>: Likewise.
	* calls.c (prepare_call_address): Remove SIBCALLP parameter and add
	FLAGS parameter.  Deal with indirect calls by descriptor and adjust.
	Set STATIC_CHAIN_REG_P on the static chain register, if any.
	(call_expr_flags): Set ECF_BY_DESCRIPTOR for calls by descriptor.
	(expand_call): Likewise.  Move around call to prepare_call_address
	and pass all flags to it.
	* cfgexpand.c (expand_call_stmt): Reinstate CALL_EXPR_BY_DESCRIPTOR.
	* gimple.h (enum gf_mask): New GF_CALL_BY_DESCRIPTOR value.
	(gimple_call_set_by_descriptor): New setter.
	(gimple_call_by_descriptor_p): New getter.
	* gimple.c (gimple_build_call_from_tree): SetCALL_EXPR_BY_DESCRIPTOR.
	(gimple_call_flags): Deal with GF_CALL_BY_DESCRIPTOR.
	* langhooks.h (struct lang_hooks): Add custom_function_descriptors.
	* langhooks-def.h (LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS): Define.
	(LANG_HOOKS_INITIALIZER): Add LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS.
	* rtl.h (STATIC_CHAIN_REG_P): New macro.
	* rtlanal.c (find_first_parameter_load): Skip static chain registers.
	* target.def (custom_function_descriptors): New POD hook.
	* tree.h (FUNC_ADDR_BY_DESCRIPTOR): New flag on ADDR_EXPR.
	(CALL_EXPR_BY_DESCRIPTOR): New flag on CALL_EXPR.
	* tree-core.h (ECF_BY_DESCRIPTOR): New mask.
	Document FUNC_ADDR_BY_DESCRIPTOR and CALL_EXPR_BY_DESCRIPTOR.
	* tree.c (make_node_stat) <tcc_declaration>: Use FUNCTION_ALIGNMENT.
	(build_common_builtin_nodes): Initialize init_descriptor and
	adjust_descriptor.
	* tree-nested.c: Include target.h.
	(struct nesting_info): Add 'any_descr_created' field.
	(get_descriptor_type): New function.
	(lookup_element_for_decl): New function extracted from...
	(create_field_for_decl): Likewise.
	(lookup_tramp_for_decl): ...here.  Adjust.
	(lookup_descr_for_decl): New function.
	(convert_tramp_reference_op): Deal with descriptors.
	(build_init_call_stmt): New function extracted from...
	(finalize_nesting_tree_1): ...here.  Adjust and deal withdescriptors.
	* defaults.h (FUNCTION_ALIGNMENT): Define.
	(TRAMPOLINE_ALIGNMENT): Set to above instead of FUNCTION_BOUNDARY.
	* config/i386/i386.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Define.
	* config/ia64/ia64.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Likewise.
	* config/rs6000/rs6000.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS):Likewise.
	* config/sparc/sparc.h (TARGET_CUSTOM_FUNCTION_DESCRIPTORS): Likewise.
ada/
	* gcc-interface/misc.c (LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS):Define.
	* gcc-interface/trans.c (Attribute_to_gnu) <Attr_Access>: Deal with
	a zero TARGET_CUSTOM_FUNCTION_DESCRIPTORS specially for Code_Address.
	Otherwise, if TARGET_CUSTOM_FUNCTION_DESCRIPTORS is positive, set
	FUNC_ADDR_BY_DESCRIPTOR for 'Access/'Unrestricted_Access of nested
	subprograms if the type can use an internal representation.
	(call_to_gnu): Likewise, but set CALL_EXPR_BY_DESCRIPTOR on indirect
	calls if the type can use an internal representation.

From-SVN: r241222

1 files changed, 60 insertions, 2 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 03d8563..ff37773 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -4608,8 +4608,9 @@ expand_builtin_init_trampoline (tree exp, bool onstack)
     {
       trampolines_created = 1;
 
-      warning_at (DECL_SOURCE_LOCATION (t_func), OPT_Wtrampolines,
-		  "trampoline generated for nested function %qD", t_func);
+      if (targetm.calls.custom_function_descriptors != 0)
+	warning_at (DECL_SOURCE_LOCATION (t_func), OPT_Wtrampolines,
+		    "trampoline generated for nested function %qD", t_func);
     }
 
   return const0_rtx;
@@ -4631,6 +4632,58 @@ expand_builtin_adjust_trampoline (tree exp)
   return tramp;
 }
 
+/* Expand a call to the builtin descriptor initialization routine.
+   A descriptor is made up of a couple of pointers to the static
+   chain and the code entry in this order.  */
+
+static rtx
+expand_builtin_init_descriptor (tree exp)
+{
+  tree t_descr, t_func, t_chain;
+  rtx m_descr, r_descr, r_func, r_chain;
+
+  if (!validate_arglist (exp, POINTER_TYPE, POINTER_TYPE, POINTER_TYPE,
+			 VOID_TYPE))
+    return NULL_RTX;
+
+  t_descr = CALL_EXPR_ARG (exp, 0);
+  t_func = CALL_EXPR_ARG (exp, 1);
+  t_chain = CALL_EXPR_ARG (exp, 2);
+
+  r_descr = expand_normal (t_descr);
+  m_descr = gen_rtx_MEM (BLKmode, r_descr);
+  MEM_NOTRAP_P (m_descr) = 1;
+
+  r_func = expand_normal (t_func);
+  r_chain = expand_normal (t_chain);
+
+  /* Generate insns to initialize the descriptor.  */
+  emit_move_insn (adjust_address_nv (m_descr, ptr_mode, 0), r_chain);
+  emit_move_insn (adjust_address_nv (m_descr, ptr_mode,
+				     POINTER_SIZE / BITS_PER_UNIT), r_func);
+
+  return const0_rtx;
+}
+
+/* Expand a call to the builtin descriptor adjustment routine.  */
+
+static rtx
+expand_builtin_adjust_descriptor (tree exp)
+{
+  rtx tramp;
+
+  if (!validate_arglist (exp, POINTER_TYPE, VOID_TYPE))
+    return NULL_RTX;
+
+  tramp = expand_normal (CALL_EXPR_ARG (exp, 0));
+
+  /* Unalign the descriptor to allow runtime identification.  */
+  tramp = plus_constant (ptr_mode, tramp,
+			 targetm.calls.custom_function_descriptors);
+
+  return force_operand (tramp, NULL_RTX);
+}
+
 /* Expand the call EXP to the built-in signbit, signbitf or signbitl
    function.  The function first checks whether the back end provides
    an insn to implement signbit for the respective mode.  If not, it
@@ -6330,6 +6383,11 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode,
     case BUILT_IN_ADJUST_TRAMPOLINE:
       return expand_builtin_adjust_trampoline (exp);
 
+    case BUILT_IN_INIT_DESCRIPTOR:
+      return expand_builtin_init_descriptor (exp);
+    case BUILT_IN_ADJUST_DESCRIPTOR:
+      return expand_builtin_adjust_descriptor (exp);
+
     case BUILT_IN_FORK:
     case BUILT_IN_EXECL:
     case BUILT_IN_EXECV: