https://gcc.gnu.org/g:a8e6360765336969e3f45ac16e4340e5e5468768
commit r15-4085-ga8e6360765336969e3f45ac16e4340e5e5468768
Author: Eric Botcazou <ebotca...@adacore.com>
Date: Sat Oct 5 14:39:14 2024 +0200
Fix various issues of -ftrivial-auto-var-init=zero with Ada
This polishes a few rough edges that prevent -ftrivial-auto-var-init=zero
from working in Ada:
- build_common_builtin_nodes declares BUILT_IN_CLEAR_PADDING with 3
instead 2 parameters, now gimple_fold_builtin_clear_padding contains
the assertion:
gcc_assert (gimple_call_num_args (stmt) == 2)
This causes gimple_builtin_call_types_compatible_p to always return false
in Ada (this works in C/C++ because another declaration is used).
- gimple_add_init_for_auto_var uses EXPR_LOCATION to fetch the location
of a DECL node, which always returns UNKNOWN_LOCATION.
- the machinery attempts to initialize Out parameters.
gcc/
PR middle-end/116933
* gimplify.cc (gimple_add_init_for_auto_var): Use the correct macro
to fetch the source location of the variable.
* tree.cc (common_builtin_nodes): Remove the 3rd parameter in the
type of BUILT_IN_CLEAR_PADDING.
gcc/ada/
PR middle-end/116933
* gcc-interface/decl.cc (gnat_to_gnu_entity) <E_Out_Parameter>: Add
the "uninitialized" attribute on Out parameters.
* gcc-interface/utils.cc (gnat_internal_attributes): Add entry for
the "uninitialized" attribute.
(handle_uninitialized_attribute): New function.
gcc/testsuite/
* gnat.dg/auto_var_init.adb: New test.
Diff:
---
gcc/ada/gcc-interface/decl.cc | 7 +++++++
gcc/ada/gcc-interface/utils.cc | 27 +++++++++++++++++++++++++++
gcc/gimplify.cc | 11 ++++-------
gcc/testsuite/gnat.dg/auto_var_init.adb | 9 +++++++++
gcc/tree.cc | 1 -
5 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index 4252e627b0ce..880eaff8d0b6 100644
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -1563,6 +1563,13 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree
gnu_expr, bool definition)
prepend_one_attribute_pragma (&attr_list,
Linker_Section_Pragma (gnat_entity));
+ /* Do not initialize Out parameters with -ftrivial-auto-var-init. */
+ if (kind == E_Out_Parameter)
+ prepend_one_attribute
+ (&attr_list, ATTR_MACHINE_ATTRIBUTE,
+ get_identifier ("uninitialized"), NULL_TREE,
+ gnat_entity);
+
/* Now create the variable or the constant and set various flags. */
gnu_decl
= create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
diff --git a/gcc/ada/gcc-interface/utils.cc b/gcc/ada/gcc-interface/utils.cc
index 60f36b1e50d1..a88a23860d3e 100644
--- a/gcc/ada/gcc-interface/utils.cc
+++ b/gcc/ada/gcc-interface/utils.cc
@@ -107,6 +107,7 @@ static tree handle_malloc_attribute (tree *, tree, tree,
int, bool *);
static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
static tree handle_flatten_attribute (tree *, tree, tree, int, bool *);
static tree handle_used_attribute (tree *, tree, tree, int, bool *);
+static tree handle_uninitialized_attribute (tree *, tree, tree, int, bool *);
static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
static tree handle_simd_attribute (tree *, tree, tree, int, bool *);
@@ -214,6 +215,8 @@ static const attribute_spec gnat_internal_attributes[] =
handle_flatten_attribute, NULL },
{ "used", 0, 0, true, false, false, false,
handle_used_attribute, NULL },
+ { "uninitialized",0, 0, true, false, false, false,
+ handle_uninitialized_attribute, NULL },
{ "cold", 0, 0, true, false, false, false,
handle_cold_attribute, attr_cold_hot_exclusions },
{ "hot", 0, 0, true, false, false, false,
@@ -7171,6 +7174,30 @@ handle_used_attribute (tree *pnode, tree name, tree
ARG_UNUSED (args),
return NULL_TREE;
}
+/* Handle an "uninitialized" attribute; arguments as in
+ struct attribute_spec.handler. */
+
+static tree
+handle_uninitialized_attribute (tree *node, tree name, tree ARG_UNUSED (args),
+ int ARG_UNUSED (flags), bool *no_add_attrs)
+{
+ tree decl = *node;
+ if (!VAR_P (decl))
+ {
+ warning (OPT_Wattributes, "%qE attribute ignored because %qD "
+ "is not a variable", name, decl);
+ *no_add_attrs = true;
+ }
+ else if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
+ {
+ warning (OPT_Wattributes, "%qE attribute ignored because %qD "
+ "is not a local variable", name, decl);
+ *no_add_attrs = true;
+ }
+
+ return NULL_TREE;
+}
+
/* Handle a "cold" and attribute; arguments as in
struct attribute_spec.handler. */
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index dd7efa71b742..6cdc70d21300 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -1993,17 +1993,14 @@ gimple_add_init_for_auto_var (tree decl,
{
gcc_assert (auto_var_p (decl));
gcc_assert (init_type > AUTO_INIT_UNINITIALIZED);
- location_t loc = EXPR_LOCATION (decl);
- tree decl_size = TYPE_SIZE_UNIT (TREE_TYPE (decl));
- tree init_type_node
- = build_int_cst (integer_type_node, (int) init_type);
+ const location_t loc = DECL_SOURCE_LOCATION (decl);
+ tree decl_size = TYPE_SIZE_UNIT (TREE_TYPE (decl));
+ tree init_type_node = build_int_cst (integer_type_node, (int) init_type);
+ tree decl_name;
- tree decl_name = NULL_TREE;
if (DECL_NAME (decl))
-
decl_name = build_string_literal (DECL_NAME (decl));
-
else
{
char decl_name_anonymous[3 + (HOST_BITS_PER_INT + 2) / 3];
diff --git a/gcc/testsuite/gnat.dg/auto_var_init.adb
b/gcc/testsuite/gnat.dg/auto_var_init.adb
new file mode 100644
index 000000000000..9f0ec7a81592
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/auto_var_init.adb
@@ -0,0 +1,9 @@
+-- { dg-do run }
+-- { dg-options "-ftrivial-auto-var-init=zero" }
+
+with Ada.Text_IO; use Ada.Text_IO;
+
+procedure Auto_Var_Init is
+begin
+ Put_Line ("Hello World!");
+end;
diff --git a/gcc/tree.cc b/gcc/tree.cc
index bc50afca9a38..095c02c54741 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -9848,7 +9848,6 @@ build_common_builtin_nodes (void)
ftype = build_function_type_list (void_type_node,
ptr_type_node,
ptr_type_node,
- integer_type_node,
NULL_TREE);
local_define_builtin ("__builtin_clear_padding", ftype,
BUILT_IN_CLEAR_PADDING,
