[binutils-gdb] Change riscv_return_value to use RETURN_VALUE_ABI_PRESERVES_ADDRESS

[Tom Tromey <tromey@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d4be21dce768ba5cddc300544a4953748187982c

commit d4be21dce768ba5cddc300544a4953748187982c
Author: Tom Tromey <tromey@adacore.com>
Date:   Tue Dec 14 08:46:59 2021 -0700

    Change riscv_return_value to use RETURN_VALUE_ABI_PRESERVES_ADDRESS
    
    Internally, AdaCore has a test that is equivalent to (really a direct
    translation of) gdb.base/gnu_vector.exp.  On 32-bit RISC-V, the
    "return" part of this test fails.
    
    Joel tracked this down to riscv_return_value returning
    RETURN_VALUE_ABI_RETURNS_ADDRESS.  Using
    RETURN_VALUE_ABI_PRESERVES_ADDRESS is more correct here, and fixes the
    bug.
    
    I tested this for both 32- and 64-bit RISC-V using the AdaCore
    internal test suite, and Andrew Burgess tested it using
    gnu_vector.exp.

Diff:
---
 gdb/riscv-tdep.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 5a6269887e7..886996ce5b7 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -3301,7 +3301,7 @@ riscv_return_value (struct gdbarch  *gdbarch,
     case riscv_arg_info::location::in_reg:
       return RETURN_VALUE_REGISTER_CONVENTION;
     case riscv_arg_info::location::by_ref:
-      return RETURN_VALUE_ABI_RETURNS_ADDRESS;
+      return RETURN_VALUE_ABI_PRESERVES_ADDRESS;
     case riscv_arg_info::location::on_stack:
     default:
       error (_("invalid argument location"));