| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // REQUIRES: linux && target={{riscv64-.+}} |
| |
| #undef NDEBUG |
| #include <assert.h> |
| #include <libunwind.h> |
| |
| // Check correct unwinding of frame with VLENB-sized objects (vector registers): |
| // 1. Save return address (ra) in temporary register. |
| // 2. Load VLENB (vector length in bytes) and substract it from current stack |
| // pointer (sp) - equivalent to one vector register on stack frame. |
| // 3. Set DWARF cannonical frame address (CFA) to "sp + vlenb" expresssion so it |
| // can be correctly unwinded. |
| // 4. Call stepper() function and check that 2 unwind steps are successful - |
| // from stepper() into foo() and from foo() into main(). |
| // 5. Restore stack pointer and return address. |
| __attribute__((naked)) static void foo() { |
| __asm__(".cfi_startproc\n" |
| "mv s0, ra\n" |
| "csrr s1, vlenb\n" |
| "sub sp, sp, s1\n" |
| "# .cfi_def_cfa_expression sp + vlenb\n" |
| ".cfi_escape 0x0f, 0x07, 0x72, 0x00, 0x92, 0xa2, 0x38, 0x00, 0x22\n" |
| "call stepper\n" |
| "add sp, sp, s1\n" |
| "mv ra, s0\n" |
| "ret\n" |
| ".cfi_endproc\n"); |
| } |
| |
| extern "C" void stepper() { |
| unw_cursor_t cursor; |
| unw_context_t uc; |
| unw_getcontext(&uc); |
| unw_init_local(&cursor, &uc); |
| // Stepping into foo() should succeed. |
| assert(unw_step(&cursor) > 0); |
| // Stepping past foo() should succeed, too. |
| assert(unw_step(&cursor) > 0); |
| } |
| |
| int main() { foo(); } |