summaryrefslogtreecommitdiffstats
path: root/src/core/hle/result.h
blob: 2c6b248486eacb2f005e6c4cfad28523526b1941 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#pragma once

#include <new>
#include <utility>
#include "common/assert.h"
#include "common/bit_field.h"
#include "common/common_types.h"

// All the constants in this file come from http://switchbrew.org/index.php?title=Error_codes

/**
 * Identifies the module which caused the error. Error codes can be propagated through a call
 * chain, meaning that this doesn't always correspond to the module where the API call made is
 * contained.
 */
enum class ErrorModule : u32 {
    Common = 0,
    Kernel = 1,
    FS = 2,
    OS = 3, // used for Memory, Thread, Mutex, Nvidia
    HTCS = 4,
    NCM = 5,
    DD = 6,
    LR = 8,
    Loader = 9,
    CMIF = 10,
    HIPC = 11,
    PM = 15,
    NS = 16,
    HTC = 18,
    NCMContent = 20,
    SM = 21,
    RO = 22,
    SDMMC = 24,
    OVLN = 25,
    SPL = 26,
    ETHC = 100,
    I2C = 101,
    GPIO = 102,
    UART = 103,
    Settings = 105,
    WLAN = 107,
    XCD = 108,
    NIFM = 110,
    Hwopus = 111,
    Bluetooth = 113,
    VI = 114,
    NFP = 115,
    Time = 116,
    FGM = 117,
    OE = 118,
    PCIe = 120,
    Friends = 121,
    BCAT = 122,
    SSLSrv = 123,
    Account = 124,
    News = 125,
    Mii = 126,
    NFC = 127,
    AM = 128,
    PlayReport = 129,
    AHID = 130,
    Qlaunch = 132,
    PCV = 133,
    OMM = 134,
    BPC = 135,
    PSM = 136,
    NIM = 137,
    PSC = 138,
    TC = 139,
    USB = 140,
    NSD = 141,
    PCTL = 142,
    BTM = 143,
    ETicket = 145,
    NGC = 146,
    ERPT = 147,
    APM = 148,
    Profiler = 150,
    ErrorUpload = 151,
    Audio = 153,
    NPNS = 154,
    NPNSHTTPSTREAM = 155,
    ARP = 157,
    SWKBD = 158,
    BOOT = 159,
    NFCMifare = 161,
    UserlandAssert = 162,
    Fatal = 163,
    NIMShop = 164,
    SPSM = 165,
    BGTC = 167,
    UserlandCrash = 168,
    SREPO = 180,
    Dauth = 181,
    HID = 202,
    LDN = 203,
    Irsensor = 205,
    Capture = 206,
    Manu = 208,
    ATK = 209,
    GRC = 212,
    Migration = 216,
    MigrationLdcServ = 217,
    GeneralWebApplet = 800,
    WifiWebAuthApplet = 809,
    WhitelistedApplet = 810,
    ShopN = 811,
};

/// Encapsulates a Horizon OS error code, allowing it to be separated into its constituent fields.
union ResultCode {
    u32 raw;

    BitField<0, 9, ErrorModule> module;
    BitField<9, 13, u32> description;

    constexpr explicit ResultCode(u32 raw_) : raw(raw_) {}

    constexpr ResultCode(ErrorModule module_, u32 description_)
        : raw(module.FormatValue(module_) | description.FormatValue(description_)) {}

    [[nodiscard]] constexpr bool IsSuccess() const {
        return raw == 0;
    }

    [[nodiscard]] constexpr bool IsError() const {
        return !IsSuccess();
    }
};

[[nodiscard]] constexpr bool operator==(const ResultCode& a, const ResultCode& b) {
    return a.raw == b.raw;
}

[[nodiscard]] constexpr bool operator!=(const ResultCode& a, const ResultCode& b) {
    return !operator==(a, b);
}

// Convenience functions for creating some common kinds of errors:

/// The default success `ResultCode`.
constexpr ResultCode ResultSuccess(0);

/**
 * Placeholder result code used for unknown error codes.
 *
 * @note This should only be used when a particular error code
 *       is not known yet.
 */
constexpr ResultCode ResultUnknown(UINT32_MAX);

/**
 * This is an optional value type. It holds a `ResultCode` and, if that code is a success code,
 * also holds a result of type `T`. If the code is an error code then trying to access the inner
 * value fails, thus ensuring that the ResultCode of functions is always checked properly before
 * their return value is used.  It is similar in concept to the `std::optional` type
 * (http://en.cppreference.com/w/cpp/experimental/optional) originally proposed for inclusion in
 * C++14, or the `Result` type in Rust (http://doc.rust-lang.org/std/result/index.html).
 *
 * An example of how it could be used:
 * \code
 * ResultVal<int> Frobnicate(float strength) {
 *     if (strength < 0.f || strength > 1.0f) {
 *         // Can't frobnicate too weakly or too strongly
 *         return ResultCode(ErrorDescription::OutOfRange, ErrorModule::Common,
 *             ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
 *     } else {
 *         // Frobnicated! Give caller a cookie
 *         return MakeResult<int>(42);
 *     }
 * }
 * \endcode
 *
 * \code
 * ResultVal<int> frob_result = Frobnicate(0.75f);
 * if (frob_result) {
 *     // Frobbed ok
 *     printf("My cookie is %d\n", *frob_result);
 * } else {
 *     printf("Guess I overdid it. :( Error code: %ux\n", frob_result.code().hex);
 * }
 * \endcode
 */
template <typename T>
class ResultVal {
public:
    /// Constructs an empty `ResultVal` with the given error code. The code must not be a success
    /// code.
    ResultVal(ResultCode error_code = ResultUnknown) : result_code(error_code) {
        ASSERT(error_code.IsError());
    }

    /**
     * Similar to the non-member function `MakeResult`, with the exception that you can manually
     * specify the success code. `success_code` must not be an error code.
     */
    template <typename... Args>
    [[nodiscard]] static ResultVal WithCode(ResultCode success_code, Args&&... args) {
        ResultVal<T> result;
        result.emplace(success_code, std::forward<Args>(args)...);
        return result;
    }

    ResultVal(const ResultVal& o) noexcept : result_code(o.result_code) {
        if (!o.empty()) {
            new (&object) T(o.object);
        }
    }

    ResultVal(ResultVal&& o) noexcept : result_code(o.result_code) {
        if (!o.empty()) {
            new (&object) T(std::move(o.object));
        }
    }

    ~ResultVal() {
        if (!empty()) {
            object.~T();
        }
    }

    ResultVal& operator=(const ResultVal& o) noexcept {
        if (this == &o) {
            return *this;
        }
        if (!empty()) {
            if (!o.empty()) {
                object = o.object;
            } else {
                object.~T();
            }
        } else {
            if (!o.empty()) {
                new (&object) T(o.object);
            }
        }
        result_code = o.result_code;

        return *this;
    }

    ResultVal& operator=(ResultVal&& o) noexcept {
        if (this == &o) {
            return *this;
        }
        if (!empty()) {
            if (!o.empty()) {
                object = std::move(o.object);
            } else {
                object.~T();
            }
        } else {
            if (!o.empty()) {
                new (&object) T(std::move(o.object));
            }
        }
        result_code = o.result_code;

        return *this;
    }

    /**
     * Replaces the current result with a new constructed result value in-place. The code must not
     * be an error code.
     */
    template <typename... Args>
    void emplace(ResultCode success_code, Args&&... args) {
        ASSERT(success_code.IsSuccess());
        if (!empty()) {
            object.~T();
        }
        new (&object) T(std::forward<Args>(args)...);
        result_code = success_code;
    }

    /// Returns true if the `ResultVal` contains an error code and no value.
    [[nodiscard]] bool empty() const {
        return result_code.IsError();
    }

    /// Returns true if the `ResultVal` contains a return value.
    [[nodiscard]] bool Succeeded() const {
        return result_code.IsSuccess();
    }
    /// Returns true if the `ResultVal` contains an error code and no value.
    [[nodiscard]] bool Failed() const {
        return empty();
    }

    [[nodiscard]] ResultCode Code() const {
        return result_code;
    }

    [[nodiscard]] const T& operator*() const {
        return object;
    }
    [[nodiscard]] T& operator*() {
        return object;
    }
    [[nodiscard]] const T* operator->() const {
        return &object;
    }
    [[nodiscard]] T* operator->() {
        return &object;
    }

    /// Returns the value contained in this `ResultVal`, or the supplied default if it is missing.
    template <typename U>
    [[nodiscard]] T ValueOr(U&& value) const {
        return !empty() ? object : std::move(value);
    }

    /// Asserts that the result succeeded and returns a reference to it.
    [[nodiscard]] T& Unwrap() & {
        ASSERT_MSG(Succeeded(), "Tried to Unwrap empty ResultVal");
        return **this;
    }

    [[nodiscard]] T&& Unwrap() && {
        ASSERT_MSG(Succeeded(), "Tried to Unwrap empty ResultVal");
        return std::move(**this);
    }

private:
    // A union is used to allocate the storage for the value, while allowing us to construct and
    // destruct it at will.
    union {
        T object;
    };
    ResultCode result_code;
};

/**
 * This function is a helper used to construct `ResultVal`s. It receives the arguments to construct
 * `T` with and creates a success `ResultVal` contained the constructed value.
 */
template <typename T, typename... Args>
[[nodiscard]] ResultVal<T> MakeResult(Args&&... args) {
    return ResultVal<T>::WithCode(ResultSuccess, std::forward<Args>(args)...);
}

/**
 * Deducible overload of MakeResult, allowing the template parameter to be ommited if you're just
 * copy or move constructing.
 */
template <typename Arg>
[[nodiscard]] ResultVal<std::remove_cvref_t<Arg>> MakeResult(Arg&& arg) {
    return ResultVal<std::remove_cvref_t<Arg>>::WithCode(ResultSuccess, std::forward<Arg>(arg));
}

/**
 * Check for the success of `source` (which must evaluate to a ResultVal). If it succeeds, unwraps
 * the contained value and assigns it to `target`, which can be either an l-value expression or a
 * variable declaration. If it fails the return code is returned from the current function. Thus it
 * can be used to cascade errors out, achieving something akin to exception handling.
 */
#define CASCADE_RESULT(target, source)                                                             \
    auto CONCAT2(check_result_L, __LINE__) = source;                                               \
    if (CONCAT2(check_result_L, __LINE__).Failed()) {                                              \
        return CONCAT2(check_result_L, __LINE__).Code();                                           \
    }                                                                                              \
    target = std::move(*CONCAT2(check_result_L, __LINE__))

/**
 * Analogous to CASCADE_RESULT, but for a bare ResultCode. The code will be propagated if
 * non-success, or discarded otherwise.
 */
#define CASCADE_CODE(source)                                                                       \
    do {                                                                                           \
        auto CONCAT2(check_result_L, __LINE__) = source;                                           \
        if (CONCAT2(check_result_L, __LINE__).IsError()) {                                         \
            return CONCAT2(check_result_L, __LINE__);                                              \
        }                                                                                          \
    } while (false)

#define R_SUCCEEDED(res) (res.IsSuccess())

/// Evaluates a boolean expression, and succeeds if that expression is true.
#define R_SUCCEED_IF(expr) R_UNLESS(!(expr), ResultSuccess)

/// Evaluates a boolean expression, and returns a result unless that expression is true.
#define R_UNLESS(expr, res)                                                                        \
    {                                                                                              \
        if (!(expr)) {                                                                             \
            if (res.IsError()) {                                                                   \
                LOG_ERROR(Kernel, "Failed with result: {}", res.raw);                              \
            }                                                                                      \
            return res;                                                                            \
        }                                                                                          \
    }

/// Evaluates an expression that returns a result, and returns the result if it would fail.
#define R_TRY(res_expr)                                                                            \
    {                                                                                              \
        const auto _tmp_r_try_rc = (res_expr);                                                     \
        if (_tmp_r_try_rc.IsError()) {                                                             \
            return _tmp_r_try_rc;                                                                  \
        }                                                                                          \
    }