binutils-gdb/gdb/testsuite/gdb.base/retval-large-struct.c
Luis Machado bab22d0640 [aarch64/arm] Properly extract the return value returned in memory
When running gdb.cp/non-trivial-retval.exp, the following shows up for
both aarch64-linux and armhf-linux:

Breakpoint 3, f1 (i1=23, i2=100) at src/gdb/testsuite/gdb.cp/non-trivial-retval.cc:35
35        A a;
(gdb) finish
Run till exit from #0  f1 (i1=23, i2=100) at src/gdb/testsuite/gdb.cp/non-trivial-retval.cc:35
main () at /src/gdb/testsuite/gdb.cp/non-trivial-retval.cc:163
163       B b = f2 (i1, i2);
Value returned is $6 = {a = -11952}
(gdb)

The return value should be {a = 123} instead. This happens because the
backends don't extract the return value from the correct location. GDB should
fetch a pointer to the memory location from X8 for aarch64 and r0 for armhf.

With the patch, gdb.cp/non-trivial-retval.exp has full passes on
aarch64-linux and armhf-linux on Ubuntu 20.04/18.04.

The problem only shows up with the "finish" command. The "call" command
works correctly and displays the correct return value.

This is also related to PR gdb/28681
(https://sourceware.org/bugzilla/show_bug.cgi?id=28681) and fixes FAIL's in
gdb.ada/mi_var_array.exp.

A new testcase is provided, and it exercises GDB's ability to "finish" a
function that returns a large struct (> 16 bytes) and display the
contents of this struct correctly. This has always been incorrect for
these backends, but no testcase exercised this particular scenario.
2022-03-14 10:38:32 +00:00

46 lines
1.1 KiB
C

/* This testcase is part of GDB, the GNU debugger.
Copyright 2022 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
struct big_struct_t
{
int int_array[5];
double double_array[5];
char char_array[5];
};
struct big_struct_t big_struct =
{
{1, 2, 3, 4, 5},
{3.25, 5.0, 6.25, 1.325, -1.95},
"abcde"
};
struct big_struct_t return_large_struct (void)
{
return big_struct;
}
int
main (int argc, char **argv)
{
struct big_struct_t test_struct;
test_struct = return_large_struct ();
return 0;
}