/* This testcase is part of GDB, the GNU debugger. Copyright 2025 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 . */ int __attribute__ ((noinline)) bar (int x) { return x + x; } /* This function should generate a prologue in shape of: push %rbp .cfi_def_cfa_offset 16 .cfi_offset %rbp, -16 mov %rsp, %rbp .cfi_def_cfa_register %rbp push %reg1 push %reg2 sub $XXX, %rsp .cfi_offset %reg2, 32 .cfi_offset %reg1, 24 So to be able to unwind a register, GDB needs to skip prologue past register pushes and stack allocation (to access .cfi directives). */ int __attribute__ ((noinline)) foo (int a, int b, int c, int d) { /* "volatile" alone isn't enough for clang to not optimize it out and allocate space on the stack. */ volatile char s[256]; for (int i = 0; i < 256; i++) s[i] = (char) (a + i); a += bar (a) + bar (b) + bar (c) + bar (d); return a; } int main (int argc, char **argv) { volatile int a = foo (argc, argc + 1, argc + 2, argc * 2); return a; }