// Copyright 2015 Ted Mielczarek. See the COPYRIGHT
// file at the top-level directory of this distribution.

// NOTE: we don't bother testing arm64_old, it should have identical code at
// all times!

use crate::*;
use minidump::system_info::{Cpu, Os};
use std::collections::HashMap;
use test_assembler::*;

type Context = minidump::format::CONTEXT_ARM64;

struct TestFixture {
    pub raw: Context,
    pub modules: MinidumpModuleList,
    pub symbols: HashMap<String, String>,
}

impl TestFixture {
    pub fn new() -> TestFixture {
        TestFixture {
            raw: Context::default(),
            // Give the two modules reasonable standard locations and names
            // for tests to play with.
            modules: MinidumpModuleList::from_modules(vec![
                MinidumpModule::new(0x40000000, 0x10000, "module1"),
                MinidumpModule::new(0x50000000, 0x10000, "module2"),
            ]),
            symbols: HashMap::new(),
        }
    }

    pub fn high_module() -> TestFixture {
        TestFixture {
            raw: Context::default(),
            // Same as new but with a really high module to stretch ptr auth stripping
            modules: MinidumpModuleList::from_modules(vec![
                MinidumpModule::new(0x40000000, 0x10000, "module1"),
                MinidumpModule::new(0x50000000, 0x10000, "module2"),
                MinidumpModule::new(0x10000000000000, 0x10000, "high-module"),
            ]),
            symbols: HashMap::new(),
        }
    }

    pub fn highest_module() -> TestFixture {
        TestFixture {
            raw: Context::default(),
            // Same as new but with a module so high it sets the maximum address bit
            // effectively disabling stripping
            modules: MinidumpModuleList::from_modules(vec![
                MinidumpModule::new(0x40000000, 0x10000, "module1"),
                MinidumpModule::new(0x50000000, 0x10000, "module2"),
                MinidumpModule::new(0xa000_0000_0000_0000, 0x10000, "highest-module"),
            ]),
            symbols: HashMap::new(),
        }
    }

    pub async fn walk_stack(&self, stack: Section) -> CallStack {
        let context = MinidumpContext {
            raw: MinidumpRawContext::Arm64(self.raw.clone()),
            valid: MinidumpContextValidity::All,
        };
        let base = stack.start().value().unwrap();
        let size = stack.size();
        let stack = stack.get_contents().unwrap();
        let stack_memory = MinidumpMemory {
            desc: Default::default(),
            base_address: base,
            size,
            bytes: &stack,
            endian: scroll::LE,
        };
        let system_info = SystemInfo {
            os: Os::Windows,
            os_version: None,
            os_build: None,
            cpu: Cpu::Arm64,
            cpu_info: None,
            cpu_microcode_version: None,
            cpu_count: 1,
        };
        let symbolizer = Symbolizer::new(string_symbol_supplier(self.symbols.clone()));
        let mut stack = CallStack::with_context(context);

        walk_stack(
            0,
            (),
            &mut stack,
            Some(UnifiedMemory::Memory(&stack_memory)),
            &self.modules,
            &system_info,
            &symbolizer,
        )
        .await;

        stack
    }

    pub fn add_symbols(&mut self, name: String, symbols: String) {
        self.symbols.insert(name, symbols);
    }
}

#[tokio::test]
async fn test_simple() {
    let mut f = TestFixture::new();
    let stack = Section::new();
    stack.start().set_const(0x80000000);
    // There should be no references to the stack in this walk: we don't
    // provide any call frame information, so trying to reconstruct the
    // context frame's caller should fail. So there's no need for us to
    // provide stack contents.
    f.raw.set_register("pc", 0x4000c020);
    f.raw.set_register("fp", 0x80000000);

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 1);
    let f = &s.frames[0];
    let m = f.module.as_ref().unwrap();
    assert_eq!(m.code_file(), "module1");
}

#[tokio::test]
async fn test_scan_without_symbols() {
    // Scanning should work without any symbols
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();

    stack = stack
        // frame 0
        .append_repeated(0, 16) // space
        .D64(0x40090000) // junk that's not
        .D64(0x60000000) // a return address
        .D64(return_address1) // actual return address
        // frame 1
        .mark(&frame1_sp)
        .append_repeated(0, 16) // space
        .D64(0xF0000000) // more junk
        .D64(0x0000000D)
        .D64(return_address2) // actual return address
        // frame 2
        .mark(&frame2_sp)
        .append_repeated(0, 64); // end of stack

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 3);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::Scan);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 2);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address1);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }

    {
        // Frame 2
        let frame = &s.frames[2];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::Scan);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 2);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address2);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame2_sp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_scan_with_symbols() {
    // Test that we can refine our scanning using symbols. Specifically we
    // should be able to reject pointers that are in modules but don't map to
    // any FUNC/PUBLIC record.
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    let stack_start = 0x80000000;
    stack.start().set_const(stack_start);

    let return_address = 0x50000200;

    let frame1_sp = Label::new();
    stack = stack
        // frame 0
        .append_repeated(0, 16) // space
        .D64(0x40090000) // junk that's not
        .D64(0x60000000) // a return address
        .D64(0x40001000) // a couple of plausible addresses
        .D64(0x5000F000) // that are not within functions
        .D64(return_address) // actual return address
        // frame 1
        .mark(&frame1_sp)
        .append_repeated(0, 64); // end of stack

    f.raw.set_register("pc", 0x40000200);
    f.raw.set_register("sp", stack.start().value().unwrap());

    f.add_symbols(
        String::from("module1"),
        // The youngest frame's function.
        String::from("FUNC 100 400 10 monotreme\n"),
    );
    f.add_symbols(
        String::from("module2"),
        // The calling frame's function.
        String::from("FUNC 100 400 10 marsupial\n"),
    );

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::Scan);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 2);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_scan_first_frame() {
    // The first (context) frame gets extra long scans, this test checks that.
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();

    stack = stack
        // frame 0
        .append_repeated(0, 16) // space
        .D64(0x40090000) // junk that's not
        .D64(0x60000000) // a return address
        .append_repeated(0, 96) // more space
        .D64(return_address1) // actual return address
        // frame 1
        .mark(&frame1_sp)
        .append_repeated(0, 32) // space
        .D64(0xF0000000) // more junk
        .D64(0x0000000D)
        .append_repeated(0, 336) // more space
        .D64(return_address2) // actual return address (won't be found)
        // frame 2
        .mark(&frame2_sp)
        .append_repeated(0, 64); // end of stack

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::Scan);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 2);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address1);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_frame_pointer() {
    // Frame-pointer-based unwinding
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();
    let frame0_fp = Label::new();
    let frame1_fp = Label::new();
    let frame2_fp = Label::new();

    stack = stack
        // frame 0
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame0_fp) // next fp will point to the next value
        .D64(&frame1_fp) // save current frame pointer
        .D64(return_address1) // save current link register
        .mark(&frame1_sp)
        // frame 1
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_fp)
        .D64(&frame2_fp)
        .D64(return_address2)
        .mark(&frame2_sp)
        // frame 2
        .append_repeated(0, 64) // Whatever values on the stack.
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address.
        .mark(&frame2_fp) // next fp will point to the next value
        .D64(0)
        .D64(0);

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("lr", 0x1fe0fe10);
    f.raw.set_register("fp", frame0_fp.value().unwrap());
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 3);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address1);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame1_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }

    {
        // Frame 2
        let frame = &s.frames[2];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address2);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame2_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame2_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_frame_pointer_stackless_leaf() {
    // Same as test_frame_pointer but frame0 is a stackless leaf.
    //
    // In the current implementation we will misunderstand this slightly
    // and basically "lose" frame 1, but still properly recover frame 2.
    // THIS TEST BREAKING MIGHT MEAN YOU'VE MADE THINGS WORK BETTER!
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();
    let frame1_fp = Label::new();
    let frame2_fp = Label::new();

    stack = stack
        // frame 0 (all junk!)
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_sp)
        // frame 1 (this is sadly dropped)
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_fp)
        .D64(&frame2_fp)
        .D64(return_address2)
        .mark(&frame2_sp)
        // frame 2
        .append_repeated(0, 64) // Whatever values on the stack.
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address.
        .mark(&frame2_fp) // next fp will point to the next value
        .D64(0)
        .D64(0);

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("lr", return_address1); // we will sadly ignore this
    f.raw.set_register("fp", frame1_fp.value().unwrap());
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 2 (found as Frame 1)
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address2);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame2_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame2_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_frame_pointer_stackful_leaf() {
    // Same as test_frame_pointer but frame0 is a stackful leaf.
    //
    // In the current implementation we will misunderstand this slightly
    // and basically "lose" frame 1, but still properly recover frame 2.
    // THIS TEST BREAKING MIGHT MEAN YOU'VE MADE THINGS WORK BETTER!
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();
    let frame1_fp = Label::new();
    let frame2_fp = Label::new();

    stack = stack
        // frame 0 (literally nothing!)
        .mark(&frame1_sp)
        // frame 1 (this is sadly dropped)
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_fp)
        .D64(&frame2_fp)
        .D64(return_address2)
        .mark(&frame2_sp)
        // frame 2
        .append_repeated(0, 64) // Whatever values on the stack.
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address.
        .mark(&frame2_fp) // next fp will point to the next value
        .D64(0)
        .D64(0);

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("lr", return_address1); // we will sadly ignore this
    f.raw.set_register("fp", frame1_fp.value().unwrap());
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 2 (found as Frame 1)
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address2);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame2_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame2_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_frame_pointer_ptr_auth_strip() {
    // Same as the basic frame pointer test but extra high bits have been set which
    // must be masked out. This is vaguely emulating Arm Pointer Authentication,
    // although very synthetically. This might break if we implement more accurate
    // stripping. But at that point we should have a better understanding of how
    // to make an "accurate" test!
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let authenticated_return_address1 = return_address1 | 0x0013_8000_0000_0000;
    let authenticated_return_address2 = return_address2 | 0x1110_0000_0000_0000;

    let frame1_sp = Label::new();
    let frame2_sp = Label::new();
    let frame0_fp = Label::new();
    let frame1_fp = Label::new();
    let frame2_fp = Label::new();
    let authenticated_frame1_fp = Label::new();
    let authenticated_frame2_fp = Label::new();

    stack = stack
        // frame 0
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame0_fp) // next fp will point to the next value
        .D64(&authenticated_frame1_fp) // save current frame pointer
        .D64(authenticated_return_address1) // save current link register
        .mark(&frame1_sp)
        // frame 1
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_fp)
        .D64(&authenticated_frame2_fp)
        .D64(authenticated_return_address2)
        .mark(&frame2_sp)
        // frame 2
        .append_repeated(0, 64) // Whatever values on the stack.
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address.
        .mark(&frame2_fp) // next fp will point to the next value
        .D64(0)
        .D64(0);

    authenticated_frame1_fp.set_const(frame1_fp.value().unwrap() | 0xa310_0000_0000_0000);
    authenticated_frame2_fp.set_const(frame2_fp.value().unwrap() | 0xf31e_8000_0000_0000);

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("lr", 0x1fe0fe10);
    f.raw.set_register("fp", frame0_fp.value().unwrap());
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 3);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address1);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame1_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }

    {
        // Frame 2
        let frame = &s.frames[2];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address2);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame2_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame2_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }
}

const CALLEE_SAVE_REGS: &[&str] = &[
    "pc", "sp", "fp", "x19", "x20", "x21", "x22", "x23", "x24", "x25", "x26", "x27", "x28",
];

fn init_cfi_state_high_module() -> (TestFixture, Section, Context, MinidumpContextValidity) {
    init_cfi_state_common(TestFixture::high_module())
}

fn init_cfi_state() -> (TestFixture, Section, Context, MinidumpContextValidity) {
    init_cfi_state_common(TestFixture::new())
}

fn init_cfi_state_common(
    mut f: TestFixture,
) -> (TestFixture, Section, Context, MinidumpContextValidity) {
    let symbols = [
        // The youngest frame's function.
        "FUNC 4000 1000 10 enchiridion\n",
        // Initially, nothing has been pushed on the stack,
        // and the return address is still in the link
        // register (x30).
        "STACK CFI INIT 4000 100 .cfa: sp 0 + .ra: x30\n",
        // Push x19, x20, the frame pointer and the link register.
        "STACK CFI 4001 .cfa: sp 32 + .ra: .cfa -8 + ^",
        " x19: .cfa -32 + ^ x20: .cfa -24 + ^ ",
        " x29: .cfa -16 + ^\n",
        // Save x19..x22 in x0..x3: verify that we populate
        // the youngest frame with all the values we have.
        "STACK CFI 4002 x19: x0 x20: x1 x21: x2 x22: x3\n",
        // Restore x19..x22. Save the non-callee-saves register x1.
        "STACK CFI 4003 .cfa: sp 40 + x1: .cfa 40 - ^",
        " x19: x19 x20: x20 x21: x21 x22: x22\n",
        // Move the .cfa back eight bytes, to point at the return
        // address, and restore the sp explicitly.
        "STACK CFI 4005 .cfa: sp 32 + x1: .cfa 32 - ^",
        " x29: .cfa 8 - ^ .ra: .cfa ^ sp: .cfa 8 +\n",
        // Recover the PC explicitly from a new stack slot;
        // provide garbage for the .ra.
        "STACK CFI 4006 .cfa: sp 40 + pc: .cfa 40 - ^\n",
        // The calling function.
        "FUNC 5000 1000 10 epictetus\n",
        // Mark it as end of stack.
        "STACK CFI INIT 5000 1000 .cfa: 0 .ra: 0\n",
        // A function whose CFI makes the stack pointer
        // go backwards.
        "FUNC 6000 1000 20 palinal\n",
        "STACK CFI INIT 6000 1000 .cfa: sp 8 - .ra: x30\n",
        // A function with CFI expressions that can't be
        // evaluated.
        "FUNC 7000 1000 20 rhetorical\n",
        "STACK CFI INIT 7000 1000 .cfa: moot .ra: ambiguous\n",
    ];
    f.add_symbols(String::from("module1"), symbols.concat());

    f.raw.set_register("pc", 0x0000_0000_4000_5510);
    f.raw.set_register("sp", 0x0000_0000_8000_0000);
    f.raw.set_register("fp", 0x0000_00a2_8112_e110);
    f.raw.set_register("x19", 0x5e68b5d5b5d55e68);
    f.raw.set_register("x20", 0x34f3ebd1ebd134f3);
    f.raw.set_register("x21", 0x74bca31ea31e74bc);
    f.raw.set_register("x22", 0x16b32dcb2dcb16b3);
    f.raw.set_register("x23", 0x21372ada2ada2137);
    f.raw.set_register("x24", 0x557dbbbbbbbb557d);
    f.raw.set_register("x25", 0x8ca748bf48bf8ca7);
    f.raw.set_register("x26", 0x21f0ab46ab4621f0);
    f.raw.set_register("x27", 0x146732b732b71467);
    f.raw.set_register("x28", 0xa673645fa673645f);

    let raw_valid = MinidumpContextValidity::All;

    let expected = f.raw.clone();
    let expected_regs = CALLEE_SAVE_REGS;
    let expected_valid = MinidumpContextValidity::Some(expected_regs.iter().copied().collect());

    let stack = Section::new();
    stack
        .start()
        .set_const(f.raw.get_register("sp", &raw_valid).unwrap());

    (f, stack, expected, expected_valid)
}

async fn check_cfi(
    f: TestFixture,
    stack: Section,
    expected: Context,
    expected_valid: MinidumpContextValidity,
) {
    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1
        if let MinidumpContextValidity::Some(ref expected_regs) = expected_valid {
            let frame = &s.frames[1];
            let valid = &frame.context.valid;
            assert_eq!(frame.trust, FrameTrust::CallFrameInfo);
            if let MinidumpContextValidity::Some(ref which) = valid {
                assert_eq!(which.len(), expected_regs.len());
            } else {
                unreachable!();
            }

            if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
                for reg in expected_regs {
                    assert_eq!(
                        ctx.get_register(reg, valid),
                        expected.get_register(reg, &expected_valid),
                        "{reg} registers didn't match!"
                    );
                }
                return;
            } else {
                unreachable!()
            }
        }
    }
    unreachable!();
}

#[tokio::test]
async fn test_cfi_at_4000() {
    let (mut f, mut stack, expected, expected_valid) = init_cfi_state();

    stack = stack.append_repeated(0, 120);

    f.raw.set_register("pc", 0x0000000040004000);
    f.raw.set_register("lr", 0x0000000040005510);

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4001() {
    let (mut f, mut stack, mut expected, expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0x5e68b5d5b5d55e68) // saved x19
        .D64(0x34f3ebd1ebd134f3) // saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0x0000_0000_4000_5510) // return address
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    f.raw.set_register("pc", 0x0000000040004001);
    f.raw.set_register("x19", 0xadc9f635a635adc9);
    f.raw.set_register("x20", 0x623135ac35ac6231);
    f.raw.set_register("fp", 0x5fc4be14be145fc4);

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4002() {
    let (mut f, mut stack, mut expected, expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0x0000_0000_4000_5510) // return address
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    f.raw.set_register("pc", 0x0000000040004002);
    f.raw.iregs[0] = 0x5e68b5d5b5d55e68; // saved x19
    f.raw.iregs[1] = 0x34f3ebd1ebd134f3; // saved x20
    f.raw.iregs[2] = 0x74bca31ea31e74bc; // saved x21
    f.raw.iregs[3] = 0x16b32dcb2dcb16b3; // saved x22
    f.raw.iregs[19] = 0xadc9f635a635adc9; // distinct callee x19
    f.raw.iregs[20] = 0x623135ac35ac6231; // distinct callee x20
    f.raw.iregs[21] = 0xac4543564356ac45; // distinct callee x21
    f.raw.iregs[22] = 0x2561562f562f2561; // distinct callee x22
    f.raw.set_register("fp", 0x5fc4be14be145fc4);

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4003() {
    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0x0000_0000_4000_5510) // return address
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004003);
    f.raw.iregs[1] = 0xfb756319fb756319;
    f.raw.set_register("fp", 0x5fc4be14be145fc4);

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4004() {
    // Should just be the same as 4003

    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0x0000_0000_4000_5510) // return address
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004004);
    f.raw.iregs[1] = 0xfb756319fb756319;
    f.raw.set_register("fp", 0x5fc4be14be145fc4);

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4005_ptr_auth_strip_apple() {
    // This is the same as the normal 4005 test but with extra garabage (auth) bits
    // set in the high 24 bits. This emulates what apple platforms looks like.

    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0xae23_80a2_8112_e110) // saved fp WITH AUTH
        .D64(0xae1d_0000_4000_5510) // return address WITH AUTH
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004005);
    f.raw.iregs[1] = 0xfb756319fb756319;

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4005_ptr_auth_strip_high() {
    // This is the same as the normal 4005 test but with extra garabage (auth) bits
    // set in the **extra** high bits. This emulates what android platforms look like.

    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state_high_module();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x1003_45a2_8112_e110) // saved fp WITH AUTH
        .D64(0x100d_f700_4000_5510) // return address WITH AUTH
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.set_register("fp", 0x0003_45a2_8112_e110);
    expected.set_register("pc", 0x000d_f700_4000_5510);
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004005);
    f.raw.iregs[1] = 0xfb756319fb756319;

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4005() {
    // Here we move the .cfa, but provide an explicit rule to recover the SP,
    // so again there should be no change in the registers recovered.

    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0x0000_0000_4000_5510) // return address
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004005);
    f.raw.iregs[1] = 0xfb756319fb756319;

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_at_4006() {
    // Here we provide an explicit rule for the PC, and have the saved .ra be
    // bogus.

    let (mut f, mut stack, mut expected, mut expected_valid) = init_cfi_state();

    let frame1_sp = Label::new();
    stack = stack
        .D64(0x0000000040005510) // saved pc
        .D64(0xdd5a48c848c8dd5a) // saved x1 (even though it's not callee-saves)
        .D64(0xff3dfb81fb81ff3d) // no longer saved x19
        .D64(0x34f3ebd1ebd134f3) // no longer saved x20
        .D64(0x0000_00a2_8112_e110) // saved fp
        .D64(0xf8d157835783f8d1) // .ra rule recovers this, which is garbage
        .mark(&frame1_sp)
        .append_repeated(0, 120);

    expected.set_register("sp", frame1_sp.value().unwrap());
    expected.iregs[1] = 0xdd5a48c848c8dd5a;
    if let MinidumpContextValidity::Some(ref mut which) = expected_valid {
        which.insert("x1");
    } else {
        unreachable!();
    }

    f.raw.set_register("pc", 0x0000000040004006);
    f.raw.iregs[1] = 0xfb756319fb756319;

    check_cfi(f, stack, expected, expected_valid).await;
}

#[tokio::test]
async fn test_cfi_reject_backwards() {
    // Check that we reject rules that would cause the stack pointer to
    // move in the wrong direction.

    let (mut f, mut stack, _expected, _expected_valid) = init_cfi_state();

    stack = stack.append_repeated(0, 120);

    f.raw.set_register("pc", 0x0000000040006000);
    f.raw.set_register("sp", 0x0000000080000000);
    f.raw.set_register("lr", 0x0000000040005510);

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 1);
}

#[tokio::test]
async fn test_cfi_reject_bad_exprs() {
    // Check that we reject rules whose expressions' evaluation fails.

    let (mut f, mut stack, _expected, _expected_valid) = init_cfi_state();

    stack = stack.append_repeated(0, 120);

    f.raw.set_register("pc", 0x0000000040007000);
    f.raw.set_register("sp", 0x0000000080000000);

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 1);
}

#[tokio::test]
async fn test_frame_pointer_overflow() {
    // Make sure we don't explode when trying frame pointer analysis on a value
    // that will overflow.

    type Pointer = u64;
    let stack_max: Pointer = Pointer::MAX;
    let stack_size: Pointer = 1000;
    let bad_frame_ptr: Pointer = stack_max;

    let mut f = TestFixture::new();
    let mut stack = Section::new();
    let stack_start: Pointer = stack_max - stack_size;
    stack.start().set_const(stack_start);

    stack = stack
        // frame 0
        .append_repeated(0, stack_size as usize); // junk, not important to the test

    f.raw.set_register("pc", 0x00007400c0000200);
    f.raw.set_register("fp", bad_frame_ptr);
    f.raw
        .set_register("sp", stack.start().value().unwrap() as Pointer);
    f.raw.set_register("lr", 0x00007500b0000110);

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 1);

    // As long as we don't panic, we're good!
}

#[tokio::test]
async fn test_frame_pointer_barely_no_overflow() {
    // This is a simple frame pointer test but with the all the values pushed
    // as close to the upper memory boundary as possible, to confirm that
    // our code doesn't randomly overflow *AND* isn't overzealous in
    // its overflow guards.

    // We set the highest module here to bypass ptr auth stripping entirely and stress overflows
    let mut f = TestFixture::highest_module();

    let mut stack = Section::new();

    type Pointer = u64;
    let stack_max: Pointer = Pointer::MAX;
    let pointer_size: Pointer = std::mem::size_of::<Pointer>() as Pointer;
    let stack_size: Pointer = pointer_size * 3;

    let stack_start: Pointer = stack_max - stack_size;
    let return_address: Pointer = 0x00007500b0000110;
    stack.start().set_const(stack_start);

    let frame0_fp = Label::new();
    let frame1_sp = Label::new();
    let frame1_fp = Label::new();

    stack = stack
        // frame 0
        .mark(&frame0_fp)
        .D64(&frame1_fp) //
        .D64(return_address) // actual return address
        // frame 1
        .mark(&frame1_sp)
        .mark(&frame1_fp) // end of stack
        .D64(0);

    f.raw.set_register("pc", 0x00007400c0000200);
    f.raw
        .set_register("fp", frame0_fp.value().unwrap() as Pointer);
    f.raw
        .set_register("sp", stack.start().value().unwrap() as Pointer);
    f.raw.set_register("lr", return_address);

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame0_fp.value().unwrap() as Pointer
            );
        } else {
            unreachable!();
        }
    }

    {
        // Frame 1
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap() as Pointer
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame1_fp.value().unwrap() as Pointer
            );
        } else {
            unreachable!();
        }
    }
}

#[tokio::test]
async fn test_frame_pointer_infinite_equality() {
    // Leaf functions on Arm are allowed to not update the stack pointer, so
    // it's valid for the frame pointer analysis to conclude that the stack
    // pointer doesn't change. However we must only provide this allowance
    // to the first stack frame, or else we're vulnerable to infinite loops.
    //
    // One of the CFI tests already checks that we allow the leaf case to work,
    // so here we test that we don't get stuck in an infinite loop for the
    // non-leaf case.
    //
    // This is just a copy-paste of test_frame_pointer except for the line
    // "EVIL INFINITE FRAME POINTER" has been changed from frame2_fp to frame1_fp.
    let mut f = TestFixture::new();
    let mut stack = Section::new();
    stack.start().set_const(0x80000000);

    let return_address1 = 0x50000100u64;
    let return_address2 = 0x50000900u64;
    let frame1_sp = Label::new();
    let frame2_sp = Label::new();
    let frame0_fp = Label::new();
    let frame1_fp = Label::new();
    let frame2_fp = Label::new();

    stack = stack
        // frame 0
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame0_fp) // next fp will point to the next value
        .D64(&frame0_fp) // EVIL INFINITE FRAME POINTER
        .D64(return_address1) // save current link register
        .mark(&frame1_sp)
        // frame 1
        .append_repeated(0, 64) // space
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address
        .mark(&frame1_fp)
        .D64(&frame2_fp)
        .D64(return_address2)
        .mark(&frame2_sp)
        // frame 2
        .append_repeated(0, 64) // Whatever values on the stack.
        .D64(0x0000000D) // junk that's not
        .D64(0xF0000000) // a return address.
        .mark(&frame2_fp) // next fp will point to the next value
        .D64(0)
        .D64(0);

    f.raw.set_register("pc", 0x40005510);
    f.raw.set_register("lr", 0x1fe0fe10);
    f.raw.set_register("fp", frame0_fp.value().unwrap());
    f.raw.set_register("sp", stack.start().value().unwrap());

    let s = f.walk_stack(stack).await;
    assert_eq!(s.frames.len(), 2);

    {
        // Frame 0
        let frame = &s.frames[0];
        assert_eq!(frame.trust, FrameTrust::Context);
        assert_eq!(frame.context.valid, MinidumpContextValidity::All);
    }

    {
        // Frame 1 (a messed up hybrid of frame0 and frame1)
        let frame = &s.frames[1];
        let valid = &frame.context.valid;
        assert_eq!(frame.trust, FrameTrust::FramePointer);
        if let MinidumpContextValidity::Some(ref which) = valid {
            assert_eq!(which.len(), 3);
        } else {
            unreachable!();
        }

        if let MinidumpRawContext::Arm64(ctx) = &frame.context.raw {
            assert_eq!(ctx.get_register("pc", valid).unwrap(), return_address1);
            assert_eq!(
                ctx.get_register("sp", valid).unwrap(),
                frame1_sp.value().unwrap()
            );
            assert_eq!(
                ctx.get_register("fp", valid).unwrap(),
                frame0_fp.value().unwrap()
            );
        } else {
            unreachable!();
        }
    }

    // Never get to frame 2, alas!
}