From: Eric Botcazou <ebotca...@adacore.com>
The return mechanism of functions is reported when the -gnatRm switch is
specified, but it is incorrect when the result type is not a by-reference
type in the language sense but is nevertheless returned by reference.
gcc/ada/
* gcc-interface/decl.cc: Include function.h.
(gnat_to_gnu_param): Minor comment tweaks.
(gnat_to_gnu_subprog_type): Take into account the default for the
computation of the return mechanism. Give a warning if a by-copy
specified mechanism cannot be honored.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/gcc-interface/decl.cc | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index 23983742605..aa31a888818 100644
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -27,6 +27,7 @@
#include "system.h"
#include "coretypes.h"
#include "target.h"
+#include "function.h"
#include "tree.h"
#include "gimple-expr.h"
#include "stringpool.h"
@@ -5703,6 +5704,7 @@ gnat_to_gnu_param (Entity_Id gnat_param, tree
gnu_param_type, bool first,
input_location = saved_location;
+ /* Warn if we are asked to pass by copy but cannot. */
if (mech == By_Copy && (by_ref || by_component_ptr))
post_error ("??cannot pass & by copy", gnat_param);
@@ -5735,12 +5737,13 @@ gnat_to_gnu_param (Entity_Id gnat_param, tree
gnu_param_type, bool first,
DECL_RESTRICTED_ALIASING_P (gnu_param) = restricted_aliasing_p;
Sloc_to_locus (Sloc (gnat_param), &DECL_SOURCE_LOCATION (gnu_param));
- /* If no Mechanism was specified, indicate what we're using, then
- back-annotate it. */
+ /* If no Mechanism was specified, indicate what we will use. */
if (mech == Default)
mech = (by_ref || by_component_ptr) ? By_Reference : By_Copy;
+ /* Back-annotate the mechanism in all cases. */
Set_Mechanism (gnat_param, mech);
+
return gnu_param;
}
@@ -6129,11 +6132,6 @@ gnat_to_gnu_subprog_type (Entity_Id gnat_subprog, bool
definition,
associate_subprog_with_dummy_type (gnat_subprog, gnu_return_type);
incomplete_profile_p = true;
}
-
- if (kind == E_Function)
- Set_Mechanism (gnat_subprog, return_by_direct_ref_p
- || return_by_invisi_ref_p
- ? By_Reference : By_Copy);
}
/* A procedure (something that doesn't return anything) shouldn't be
@@ -6636,6 +6634,28 @@ gnat_to_gnu_subprog_type (Entity_Id gnat_subprog, bool
definition,
if (warn_shadow)
post_error ("'G'C'C builtin not found for&!??", gnat_subprog);
}
+
+ /* Finally deal with the return mechanism for a function. */
+ if (kind == E_Function)
+ {
+ /* We return by reference either if this is required by the semantics
+ of the language or if this is the default for the function. */
+ const bool by_ref = return_by_direct_ref_p
+ || return_by_invisi_ref_p
+ || aggregate_value_p (gnu_return_type, gnu_type);
+ Mechanism_Type mech = Mechanism (gnat_subprog);
+
+ /* Warn if we are asked to return by copy but cannot. */
+ if (mech == By_Copy && by_ref)
+ post_error ("??cannot return from & by copy", gnat_subprog);
+
+ /* If no mechanism was specified, indicate what we will use. */
+ if (mech == Default)
+ mech = by_ref ? By_Reference : By_Copy;
+
+ /* Back-annotate the mechanism in all cases. */
+ Set_Mechanism (gnat_subprog, mech);
+ }
}
*param_list = gnu_param_list;
--
2.45.1
