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const std = @import("std");
const builtin = @import("builtin");
const debug = std.debug;
const testing = std.testing;
noinline fn frame3(expected: *[4]usize, unwound: *[4]usize) void {
expected[0] = @returnAddress();
var context: debug.ThreadContext = undefined;
testing.expect(debug.getContext(&context)) catch @panic("failed to getContext");
const debug_info = debug.getSelfDebugInfo() catch @panic("failed to openSelfDebugInfo");
var it = debug.StackIterator.initWithContext(expected[0], debug_info, &context) catch @panic("failed to initWithContext");
defer it.deinit();
for (unwound) |*addr| {
if (it.next()) |return_address| addr.* = return_address;
}
}
noinline fn frame2(expected: *[4]usize, unwound: *[4]usize) void {
// Excercise different __unwind_info / DWARF CFI encodings by forcing some registers to be restored
if (builtin.target.ofmt != .c) {
switch (builtin.cpu.arch) {
.x86 => {
if (builtin.omit_frame_pointer) {
asm volatile (
\\movl $3, %%ebx
\\movl $1, %%ecx
\\movl $2, %%edx
\\movl $7, %%edi
\\movl $6, %%esi
\\movl $5, %%ebp
::: "ebx", "ecx", "edx", "edi", "esi", "ebp");
} else {
asm volatile (
\\movl $3, %%ebx
\\movl $1, %%ecx
\\movl $2, %%edx
\\movl $7, %%edi
\\movl $6, %%esi
::: "ebx", "ecx", "edx", "edi", "esi");
}
},
.x86_64 => {
if (builtin.omit_frame_pointer) {
asm volatile (
\\movq $3, %%rbx
\\movq $12, %%r12
\\movq $13, %%r13
\\movq $14, %%r14
\\movq $15, %%r15
\\movq $6, %%rbp
::: "rbx", "r12", "r13", "r14", "r15", "rbp");
} else {
asm volatile (
\\movq $3, %%rbx
\\movq $12, %%r12
\\movq $13, %%r13
\\movq $14, %%r14
\\movq $15, %%r15
::: "rbx", "r12", "r13", "r14", "r15");
}
},
else => {},
}
}
expected[1] = @returnAddress();
frame3(expected, unwound);
}
noinline fn frame1(expected: *[4]usize, unwound: *[4]usize) void {
expected[2] = @returnAddress();
// Use a stack frame that is too big to encode in __unwind_info's stack-immediate encoding
// to exercise the stack-indirect encoding path
var pad: [std.math.maxInt(u8) * @sizeOf(usize) + 1]u8 = undefined;
_ = std.mem.doNotOptimizeAway(&pad);
frame2(expected, unwound);
}
noinline fn frame0(expected: *[4]usize, unwound: *[4]usize) void {
expected[3] = @returnAddress();
frame1(expected, unwound);
}
pub fn main() !void {
// Disabled until the DWARF unwinder bugs on .aarch64 are solved
if (builtin.omit_frame_pointer and comptime builtin.target.isDarwin() and builtin.cpu.arch == .aarch64) return;
if (!std.debug.have_ucontext or !std.debug.have_getcontext) return;
var expected: [4]usize = undefined;
var unwound: [4]usize = undefined;
frame0(&expected, &unwound);
try testing.expectEqual(expected, unwound);
}
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