/* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call
or an N_Procedure_Call_Statement, to a GCC tree, which is returned.
GNU_RESULT_TYPE_P is a pointer to where we should place the result type.
- If GNU_TARGET is non-null, this must be a function call and the result
- of the call is to be placed into that object. */
+ If GNU_TARGET is non-null, this must be a function call on the RHS of a
+ N_Assignment_Statement and the result is to be placed into that object. */
static tree
call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target)
tree gnu_before_list = NULL_TREE;
tree gnu_after_list = NULL_TREE;
tree gnu_call;
+ bool went_into_elab_proc = false;
gcc_assert (TREE_CODE (gnu_subprog_type) == FUNCTION_TYPE);
else
gnat_formal = First_Formal_With_Extras (Entity (Name (gnat_node)));
+ /* If we are translating a statement, open a new nesting level that will
+ surround it to declare the temporaries created for the call. */
+ if (Nkind (gnat_node) == N_Procedure_Call_Statement || gnu_target)
+ {
+ start_stmt_group ();
+ gnat_pushlevel ();
+ }
+
+ /* The lifetime of the temporaries created for the call ends with the call
+ so we can give them the scope of the elaboration routine at top level. */
+ else if (!current_function_decl)
+ {
+ current_function_decl = TREE_VALUE (gnu_elab_proc_stack);
+ went_into_elab_proc = true;
+ }
+
/* Create the list of the actual parameters as GCC expects it, namely a
chain of TREE_LIST nodes in which the TREE_VALUE field of each node
is an expression and the TREE_PURPOSE field is null. But skip Out
&& (gnu_name_type = gnat_to_gnu_type (Etype (gnat_name)))
&& !addressable_p (gnu_name, gnu_name_type))
{
- tree gnu_copy = gnu_name;
+ tree gnu_orig = gnu_name, gnu_temp, gnu_stmt;
+
+ /* Do not issue warnings for CONSTRUCTORs since this is not a copy
+ but sort of an instantiation for them. */
+ if (TREE_CODE (gnu_name) == CONSTRUCTOR)
+ ;
+
+ /* If the type is passed by reference, a copy is not allowed. */
+ else if (TREE_ADDRESSABLE (gnu_formal_type))
+ post_error ("misaligned actual cannot be passed by reference",
+ gnat_actual);
+
+ /* For users of Starlet we issue a warning because the interface
+ apparently assumes that by-ref parameters outlive the procedure
+ invocation. The code still will not work as intended, but we
+ cannot do much better since low-level parts of the back-end
+ would allocate temporaries at will because of the misalignment
+ if we did not do so here. */
+ else if (Is_Valued_Procedure (Entity (Name (gnat_node))))
+ {
+ post_error
+ ("?possible violation of implicit assumption", gnat_actual);
+ post_error_ne
+ ("?made by pragma Import_Valued_Procedure on &", gnat_actual,
+ Entity (Name (gnat_node)));
+ post_error_ne ("?because of misalignment of &", gnat_actual,
+ gnat_formal);
+ }
/* If the actual type of the object is already the nominal type,
we have nothing to do, except if the size is self-referential
&& !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_name_type)))
;
- /* Otherwise remove unpadding from the object and reset the copy. */
+ /* Otherwise remove the unpadding from all the objects. */
else if (TREE_CODE (gnu_name) == COMPONENT_REF
&& TYPE_IS_PADDING_P
(TREE_TYPE (TREE_OPERAND (gnu_name, 0))))
- gnu_name = gnu_copy = TREE_OPERAND (gnu_name, 0);
+ gnu_orig = gnu_name = TREE_OPERAND (gnu_name, 0);
/* Otherwise convert to the nominal type of the object if it's
a record type. There are several cases in which we need to
gnu_name_type)))
gnu_name = convert (gnu_name_type, gnu_name);
- /* Make a SAVE_EXPR to force the creation of a temporary. Special
- code in gnat_gimplify_expr ensures that the same temporary is
- used as the object and copied back after the call if needed. */
- gnu_name = build1 (SAVE_EXPR, TREE_TYPE (gnu_name), gnu_name);
- TREE_SIDE_EFFECTS (gnu_name) = 1;
-
- /* If the type is passed by reference, a copy is not allowed. */
- if (TREE_ADDRESSABLE (gnu_formal_type))
- {
- post_error ("misaligned actual cannot be passed by reference",
- gnat_actual);
+ /* Create an explicit temporary holding the copy. This ensures that
+ its lifetime is as narrow as possible around a statement. */
+ gnu_temp = create_var_decl (create_tmp_var_name ("A"), NULL_TREE,
+ TREE_TYPE (gnu_name), NULL_TREE, false,
+ false, false, false, NULL, Empty);
+ DECL_ARTIFICIAL (gnu_temp) = 1;
+ DECL_IGNORED_P (gnu_temp) = 1;
- /* Avoid the back-end assertion on temporary creation. */
- gnu_name = TREE_OPERAND (gnu_name, 0);
- }
+ /* But initialize it on the fly like for an implicit temporary as
+ we aren't necessarily dealing with a statement. */
+ gnu_stmt
+ = build_binary_op (INIT_EXPR, NULL_TREE, gnu_temp, gnu_name);
+ set_expr_location_from_node (gnu_stmt, gnat_actual);
- /* For users of Starlet we issue a warning because the interface
- apparently assumes that by-ref parameters outlive the procedure
- invocation. The code still will not work as intended, but we
- cannot do much better since low-level parts of the back-end
- would allocate temporaries at will because of the misalignment
- if we did not do so here. */
- else if (Is_Valued_Procedure (Entity (Name (gnat_node))))
- {
- post_error
- ("?possible violation of implicit assumption", gnat_actual);
- post_error_ne
- ("?made by pragma Import_Valued_Procedure on &", gnat_actual,
- Entity (Name (gnat_node)));
- post_error_ne ("?because of misalignment of &", gnat_actual,
- gnat_formal);
- }
+ /* From now on, the real object is the temporary. */
+ gnu_name = build2 (COMPOUND_EXPR, TREE_TYPE (gnu_name), gnu_stmt,
+ gnu_temp);
/* Set up to move the copy back to the original if needed. */
if (Ekind (gnat_formal) != E_In_Parameter)
{
- tree stmt = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_copy,
- gnu_name);
- set_expr_location_from_node (stmt, gnat_node);
- append_to_statement_list (stmt, &gnu_after_list);
+ gnu_stmt = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_orig,
+ gnu_temp);
+ set_expr_location_from_node (gnu_stmt, gnat_node);
+ append_to_statement_list (gnu_stmt, &gnu_after_list);
}
}
gnu_actual
= emit_range_check (gnu_actual, Etype (gnat_formal), gnat_actual);
- /* And convert it to this type. */
- if (TREE_CODE (gnu_actual) != SAVE_EXPR)
- gnu_actual = convert (gnu_formal_type, gnu_actual);
-
/* Unless this is an In parameter, we must remove any justified modular
building from GNU_NAME to get an lvalue. */
if (Ekind (gnat_formal) != E_In_Parameter
/* If we have not saved a GCC object for the formal, it means it is an
Out parameter not passed by reference and that need not be copied in.
- Otherwise, first see if the PARM_DECL is passed by reference. */
+ Otherwise, first see if the parameter is passed by reference. */
if (gnu_formal
&& TREE_CODE (gnu_formal) == PARM_DECL
&& DECL_BY_REF_P (gnu_formal))
gnu_actual = gnu_name;
/* If we have a padded type, be sure we've removed padding. */
- if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual))
- && TREE_CODE (gnu_actual) != SAVE_EXPR)
+ if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual)))
gnu_actual = convert (get_unpadded_type (Etype (gnat_actual)),
gnu_actual);
and takes its address. */
if (TREE_CODE (TREE_TYPE (gnu_actual)) == RECORD_TYPE
&& TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (gnu_actual))
- && TREE_CODE (gnu_actual) != SAVE_EXPR
&& Is_Constr_Subt_For_UN_Aliased (Etype (gnat_actual))
&& Is_Array_Type (Etype (gnat_actual)))
gnu_actual = convert (gnat_to_gnu_type (Etype (gnat_actual)),
gnu_actual);
}
+ /* There is no need to convert the actual to the formal's type before
+ taking its address. The only exception is for unconstrained array
+ types because of the way we build fat pointers. */
+ else if (TREE_CODE (gnu_formal_type) == UNCONSTRAINED_ARRAY_TYPE)
+ gnu_actual = convert (gnu_formal_type, gnu_actual);
+
/* The symmetry of the paths to the type of an entity is broken here
since arguments don't know that they will be passed by ref. */
gnu_formal_type = TREE_TYPE (get_gnu_tree (gnat_formal));
possibility that the ARRAY_REF might return a constant and we'd be
getting the wrong address. Neither approach is exactly correct,
but this is the most likely to work in all cases. */
- gnu_actual = convert (gnu_formal_type,
- build_unary_op (ADDR_EXPR, NULL_TREE,
- gnu_actual));
+ gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual);
}
else if (gnu_formal
&& TREE_CODE (gnu_formal) == PARM_DECL
&& DECL_BY_DESCRIPTOR_P (gnu_formal))
{
+ gnu_actual = convert (gnu_formal_type, gnu_actual);
+
/* If this is 'Null_Parameter, pass a zero descriptor. */
if ((TREE_CODE (gnu_actual) == INDIRECT_REF
|| TREE_CODE (gnu_actual) == UNCONSTRAINED_ARRAY_REF)
continue;
}
+ gnu_actual = convert (gnu_formal_type, gnu_actual);
+
/* If this is 'Null_Parameter, pass a zero even though we are
dereferencing it. */
if (TREE_CODE (gnu_actual) == INDIRECT_REF
if (Nkind (gnat_node) == N_Function_Call)
{
tree gnu_result = gnu_call;
- enum tree_code op_code;
/* If the function returns an unconstrained array or by direct reference,
we have to dereference the pointer. */
if (gnu_target)
{
+ Node_Id gnat_parent = Parent (gnat_node);
+ enum tree_code op_code;
+
+ /* If range check is needed, emit code to generate it. */
+ if (Do_Range_Check (gnat_node))
+ gnu_result
+ = emit_range_check (gnu_result, Etype (Name (gnat_parent)),
+ gnat_parent);
+
/* ??? If the return type has non-constant size, then force the
return slot optimization as we would not be able to generate
a temporary. That's what has been done historically. */
gnu_result
= build_binary_op (op_code, NULL_TREE, gnu_target, gnu_result);
+ add_stmt_with_node (gnu_result, gnat_parent);
+ gnat_poplevel ();
+ gnu_result = end_stmt_group ();
}
else
- *gnu_result_type_p = get_unpadded_type (Etype (gnat_node));
+ {
+ if (went_into_elab_proc)
+ current_function_decl = NULL_TREE;
+ *gnu_result_type_p = get_unpadded_type (Etype (gnat_node));
+ }
return gnu_result;
}
passing mechanism must be used. */
if (TYPE_CI_CO_LIST (gnu_subprog_type))
{
- /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
- in copy out parameters. */
+ /* List of FIELD_DECLs associated with the PARM_DECLs of the copy-in/
+ copy-out parameters. */
tree gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type);
const int length = list_length (gnu_cico_list);
if (length > 1)
{
+ tree gnu_temp, gnu_stmt;
+
/* The call sequence must contain one and only one call, even though
- the function is const or pure. So force a SAVE_EXPR. */
- gnu_call = build1 (SAVE_EXPR, TREE_TYPE (gnu_call), gnu_call);
- TREE_SIDE_EFFECTS (gnu_call) = 1;
+ the function is pure. Save the result into a temporary. */
+ gnu_temp = create_var_decl (create_tmp_var_name ("R"), NULL_TREE,
+ TREE_TYPE (gnu_call), NULL_TREE, false,
+ false, false, false, NULL, Empty);
+ DECL_ARTIFICIAL (gnu_temp) = 1;
+ DECL_IGNORED_P (gnu_temp) = 1;
+
+ gnu_stmt
+ = build_binary_op (INIT_EXPR, NULL_TREE, gnu_temp, gnu_call);
+ set_expr_location_from_node (gnu_stmt, gnat_node);
+
+ /* Add the call statement to the list and start from its result. */
+ append_to_statement_list (gnu_stmt, &gnu_before_list);
+ gnu_call = gnu_temp;
+
gnu_name_list = nreverse (gnu_name_list);
}
append_to_statement_list (gnu_after_list, &gnu_before_list);
- return gnu_before_list;
+ add_stmt (gnu_before_list);
+ gnat_poplevel ();
+ return end_stmt_group ();
}
\f
/* Subroutine of gnat_to_gnu to translate gnat_node, an
case N_Assignment_Statement:
/* Get the LHS and RHS of the statement and convert any reference to an
- unconstrained array into a reference to the underlying array.
- If we are not to do range checking and the RHS is an N_Function_Call,
- pass the LHS to the call function. */
+ unconstrained array into a reference to the underlying array. */
gnu_lhs = maybe_unconstrained_array (gnat_to_gnu (Name (gnat_node)));
/* If the type has a size that overflows, convert this into raise of
&& TREE_OVERFLOW (TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs))))
gnu_result = build_call_raise (SE_Object_Too_Large, gnat_node,
N_Raise_Storage_Error);
- else if (Nkind (Expression (gnat_node)) == N_Function_Call
- && !Do_Range_Check (Expression (gnat_node)))
- gnu_result = call_to_gnu (Expression (gnat_node),
- &gnu_result_type, gnu_lhs);
+ else if (Nkind (Expression (gnat_node)) == N_Function_Call)
+ gnu_result
+ = call_to_gnu (Expression (gnat_node), &gnu_result_type, gnu_lhs);
else
{
gnu_rhs
return GS_ALL_DONE;
}
- /* If we are taking the address of a SAVE_EXPR, we are typically dealing
- with a misaligned argument to be passed by reference in a subprogram
- call. We cannot let the common gimplifier code perform the creation
- of the temporary and its initialization because, in order to ensure
- that the final copy operation is a store and since the temporary made
- for a SAVE_EXPR is not addressable, it may create another temporary,
- addressable this time, which would break the back copy mechanism for
- an IN OUT parameter. */
- if (TREE_CODE (op) == SAVE_EXPR && !SAVE_EXPR_RESOLVED_P (op))
- {
- tree mod, val = TREE_OPERAND (op, 0);
- tree new_var = create_tmp_var (TREE_TYPE (op), "S");
- TREE_ADDRESSABLE (new_var) = 1;
-
- mod = build2 (INIT_EXPR, TREE_TYPE (new_var), new_var, val);
- if (EXPR_HAS_LOCATION (val))
- SET_EXPR_LOCATION (mod, EXPR_LOCATION (val));
- gimplify_and_add (mod, pre_p);
- ggc_free (mod);
-
- TREE_OPERAND (op, 0) = new_var;
- SAVE_EXPR_RESOLVED_P (op) = 1;
-
- TREE_OPERAND (expr, 0) = new_var;
- recompute_tree_invariant_for_addr_expr (expr);
- return GS_ALL_DONE;
- }
-
return GS_UNHANDLED;
case DECL_EXPR:
case UNCONSTRAINED_ARRAY_REF:
case INDIRECT_REF:
+ /* Taking the address of a dereference yields the original pointer. */
return true;
- case CONSTRUCTOR:
case STRING_CST:
case INTEGER_CST:
+ /* Taking the address yields a pointer to the constant pool. */
+ return true;
+
+ case CONSTRUCTOR:
+ /* Taking the address of a static constructor yields a pointer to the
+ tree constant pool. */
+ return TREE_STATIC (gnu_expr) ? true : false;
+
case NULL_EXPR:
case SAVE_EXPR:
case CALL_EXPR:
force a temporary to be created by the middle-end. */
return true;
+ case COMPOUND_EXPR:
+ /* The address of a compound expression is that of its 2nd operand. */
+ return addressable_p (TREE_OPERAND (gnu_expr, 1), gnu_type);
+
case COND_EXPR:
/* We accept &COND_EXPR as soon as both operands are addressable and
expect the outcome to be the address of the selected operand. */
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