From: Eric Botcazou <ebotca...@adacore.com>
Initialization procedures are turned into functions under the hood and, even
when they are null (empty), the compiler may generate a convoluted sequence
of instructions that return uninitialized data and, therefore, is useless.
gcc/ada/ChangeLog:
* gcc-interface/trans.cc (Subprogram_Body_to_gnu): Do not generate
a block-copy out for a null initialization procedure when the _Init
parameter is not passed in.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/gcc-interface/trans.cc | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/gcc/ada/gcc-interface/trans.cc b/gcc/ada/gcc-interface/trans.cc
index 520611e7d79..a7254fe036f 100644
--- a/gcc/ada/gcc-interface/trans.cc
+++ b/gcc/ada/gcc-interface/trans.cc
@@ -4172,9 +4172,13 @@ Subprogram_Body_to_gnu (Node_Id gnat_node)
}
}
- /* Otherwise, if this is a procedure or a function which does not return
- by invisible reference, we can do a direct block-copy out. */
- else
+ /* Otherwise, if this is a procedure or a function that does not return
+ by invisible reference, we can do a direct block-copy out, but we do
+ not need to do it for a null initialization procedure when the _Init
+ parameter is not passed in since we would copy uninitialized bits. */
+ else if (!(Is_Null_Init_Proc (gnat_subprog)
+ && list_length (gnu_cico_list) == 1
+ && TREE_CODE (TREE_VALUE (gnu_cico_list)) == VAR_DECL))
{
tree gnu_retval;
--
2.43.0
