path: root/src/mongo/util/assert_util.h

/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    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
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include <cstdlib>
#include <string>
#include <typeinfo>

#include "mongo/base/status.h"  // NOTE: This is safe as utils depend on base
#include "mongo/base/status_with.h"
#include "mongo/platform/compiler.h"
#include "mongo/util/concurrency/thread_name.h"
#include "mongo/util/debug_util.h"

#define MONGO_INCLUDE_INVARIANT_H_WHITELISTED
#include "mongo/util/invariant.h"
#undef MONGO_INCLUDE_INVARIANT_H_WHITELISTED

namespace mongo {

class AssertionCount {
public:
    AssertionCount();
    void rollover();
    void condrollover(int newValue);

    int regular;
    int warning;
    int msg;
    int user;
    int rollovers;
};

extern AssertionCount assertionCount;


class DBException;
std::string causedBy(const DBException& e);
std::string causedBy(const std::string& e);

/** Most mongo exceptions inherit from this; this is commonly caught in most threads */
class DBException : public std::exception {
public:
    const char* what() const throw() final {
        return reason().c_str();
    }

    virtual void addContext(StringData context) {
        _status.addContext(context);
    }

    Status toStatus(StringData context) const {
        return _status.withContext(context);
    }
    const Status& toStatus() const {
        return _status;
    }

    virtual std::string toString() const {
        return _status.toString();
    }

    const std::string& reason() const {
        return _status.reason();
    }

    ErrorCodes::Error code() const {
        return _status.code();
    }

    std::string codeString() const {
        return _status.codeString();
    }

    /**
     * Returns true if this DBException's code is a member of the given category.
     */
    template <ErrorCategory category>
    bool isA() const {
        return ErrorCodes::isA<category>(code());
    }

    /**
     * Returns the generic ErrorExtraInfo if present.
     */
    const ErrorExtraInfo* extraInfo() const {
        return _status.extraInfo();
    }

    /**
     * Returns a specific subclass of ErrorExtraInfo if the error code matches that type.
     */
    template <typename ErrorDetail>
    const ErrorDetail* extraInfo() const {
        return _status.extraInfo<ErrorDetail>();
    }

    static AtomicBool traceExceptions;

protected:
    DBException(const Status& status) : _status(status) {
        invariant(!status.isOK());
        traceIfNeeded(*this);
    }

private:
    static void traceIfNeeded(const DBException& e);

    /**
     * This method exists only to make all non-final types in this hierarchy abstract to prevent
     * accidental slicing.
     */
    virtual void defineOnlyInFinalSubclassToPreventSlicing() = 0;

    Status _status;
};

class AssertionException : public DBException {
public:
    AssertionException(const Status& status) : DBException(status) {}
};

/**
 * The base class of all DBExceptions for codes of the given ErrorCategory to allow catching by
 * category.
 */
template <ErrorCategory kCategory>
class ExceptionForCat : public virtual AssertionException {
protected:
    // This will only be called by subclasses, and they are required to instantiate
    // AssertionException themselves since it is a virtual base. Therefore, the AssertionException
    // construction here should never actually execute, but it is required to be present to allow
    // subclasses to construct us.
    ExceptionForCat() : AssertionException((std::abort(), Status::OK())) {
        invariant(isA<kCategory>());
    }
};


/**
 * This namespace contains implementation details for our error handling code and should not be used
 * directly in general code.
 */
namespace error_details {

template <ErrorCodes::Error kCode, typename... Bases>
class ExceptionForImpl final : public Bases... {
public:
    MONGO_STATIC_ASSERT(isNamedCode<kCode>);

    ExceptionForImpl(const Status& status) : AssertionException(status) {
        invariant(status.code() == kCode);
    }

    // This is only a template to enable SFINAE. It will only be instantiated with the default
    // value.
    template <ErrorCodes::Error code_copy = kCode>
    const ErrorExtraInfoFor<code_copy>* operator->() const {
        MONGO_STATIC_ASSERT(code_copy == kCode);
        return this->template extraInfo<ErrorExtraInfoFor<kCode>>();
    }

private:
    void defineOnlyInFinalSubclassToPreventSlicing() final {}
};

template <ErrorCodes::Error code, typename categories = ErrorCategoriesFor<code>>
struct ExceptionForDispatcher;

template <ErrorCodes::Error code, ErrorCategory... categories>
struct ExceptionForDispatcher<code, CategoryList<categories...>> {
    using type = std::conditional_t<sizeof...(categories) == 0,
                                    ExceptionForImpl<code, AssertionException>,
                                    ExceptionForImpl<code, ExceptionForCat<categories>...>>;
};

}  // namespace error_details


/**
 * Resolves to the concrete exception type for the given error code.
 *
 * It will be a subclass of both AssertionException, along with ExceptionForCat<> of every category
 * that the code belongs to.
 *
 * TODO in C++17 we can combine this with ExceptionForCat by doing something like:
 * template <auto codeOrCategory> using ExceptionFor = typename
 *      error_details::ExceptionForDispatcher<decltype(codeOrCategory)>::type;
 */
template <ErrorCodes::Error code>
using ExceptionFor = typename error_details::ExceptionForDispatcher<code>::type;

MONGO_COMPILER_NORETURN void verifyFailed(const char* expr, const char* file, unsigned line);
MONGO_COMPILER_NORETURN void invariantOKFailed(const char* expr,
                                               const Status& status,
                                               const char* file,
                                               unsigned line) noexcept;
MONGO_COMPILER_NORETURN void invariantOKFailedWithMsg(const char* expr,
                                                      const Status& status,
                                                      const std::string& msg,
                                                      const char* file,
                                                      unsigned line) noexcept;

#define fassertFailed MONGO_fassertFailed
#define MONGO_fassertFailed(...) ::mongo::fassertFailedWithLocation(__VA_ARGS__, __FILE__, __LINE__)
MONGO_COMPILER_NORETURN void fassertFailedWithLocation(int msgid,
                                                       const char* file,
                                                       unsigned line) noexcept;

#define fassertFailedNoTrace MONGO_fassertFailedNoTrace
#define MONGO_fassertFailedNoTrace(...) \
    ::mongo::fassertFailedNoTraceWithLocation(__VA_ARGS__, __FILE__, __LINE__)
MONGO_COMPILER_NORETURN void fassertFailedNoTraceWithLocation(int msgid,
                                                              const char* file,
                                                              unsigned line) noexcept;

#define fassertFailedWithStatus MONGO_fassertFailedWithStatus
#define MONGO_fassertFailedWithStatus(...) \
    ::mongo::fassertFailedWithStatusWithLocation(__VA_ARGS__, __FILE__, __LINE__)
MONGO_COMPILER_NORETURN void fassertFailedWithStatusWithLocation(int msgid,
                                                                 const Status& status,
                                                                 const char* file,
                                                                 unsigned line) noexcept;

#define fassertFailedWithStatusNoTrace MONGO_fassertFailedWithStatusNoTrace
#define MONGO_fassertFailedWithStatusNoTrace(...) \
    ::mongo::fassertFailedWithStatusNoTraceWithLocation(__VA_ARGS__, __FILE__, __LINE__)
MONGO_COMPILER_NORETURN void fassertFailedWithStatusNoTraceWithLocation(int msgid,
                                                                        const Status& status,
                                                                        const char* file,
                                                                        unsigned line) noexcept;

/* convert various types of exceptions to strings */
std::string causedBy(StringData e);
std::string causedBy(const char* e);
std::string causedBy(const DBException& e);
std::string causedBy(const std::exception& e);
std::string causedBy(const std::string& e);
std::string causedBy(const std::string* e);
std::string causedBy(const Status& e);

#define fassert MONGO_fassert
#define MONGO_fassert(...) ::mongo::fassertWithLocation(__VA_ARGS__, __FILE__, __LINE__)

/** aborts on condition failure */
inline void fassertWithLocation(int msgid, bool testOK, const char* file, unsigned line) {
    if (MONGO_unlikely(!testOK)) {
        fassertFailedWithLocation(msgid, file, line);
    }
}

template <typename T>
inline T fassertWithLocation(int msgid, StatusWith<T> sw, const char* file, unsigned line) {
    if (MONGO_unlikely(!sw.isOK())) {
        fassertFailedWithStatusWithLocation(msgid, sw.getStatus(), file, line);
    }
    return std::move(sw.getValue());
}

inline void fassertWithLocation(int msgid, const Status& status, const char* file, unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        fassertFailedWithStatusWithLocation(msgid, status, file, line);
    }
}

#define fassertNoTrace MONGO_fassertNoTrace
#define MONGO_fassertNoTrace(...) \
    ::mongo::fassertNoTraceWithLocation(__VA_ARGS__, __FILE__, __LINE__)
inline void fassertNoTraceWithLocation(int msgid, bool testOK, const char* file, unsigned line) {
    if (MONGO_unlikely(!testOK)) {
        fassertFailedNoTraceWithLocation(msgid, file, line);
    }
}

template <typename T>
inline T fassertNoTraceWithLocation(int msgid, StatusWith<T> sw, const char* file, unsigned line) {
    if (MONGO_unlikely(!sw.isOK())) {
        fassertFailedWithStatusNoTraceWithLocation(msgid, sw.getStatus(), file, line);
    }
    return std::move(sw.getValue());
}

inline void fassertNoTraceWithLocation(int msgid,
                                       const Status& status,
                                       const char* file,
                                       unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        fassertFailedWithStatusNoTraceWithLocation(msgid, status, file, line);
    }
}

namespace error_details {

// This function exists so that uassert/massert can take plain int literals rather than requiring
// ErrorCodes::Error wrapping.
template <typename StringLike>
Status makeStatus(int code, StringLike&& message) {
    return Status(ErrorCodes::Error(code), std::forward<StringLike>(message));
}

template <typename ErrorDetail,
          typename StringLike,
          typename = stdx::enable_if_t<
              std::is_base_of<ErrorExtraInfo, std::remove_reference_t<ErrorDetail>>::value>>
Status makeStatus(ErrorDetail&& detail, StringLike&& message) {
    return Status(std::forward<ErrorDetail>(detail), std::forward<StringLike>(message));
}

}  // namespace error_details

/**
 * Common implementation for assert and assertFailed macros. Not for direct use.
 *
 * Using an immediately invoked lambda to give the compiler an easy way to inline the check (expr)
 * and out-of-line the error path. This is most helpful when the error path involves building a
 * complex error message in the expansion of msg. The call to the lambda is followed by
 * MONGO_COMPILER_UNREACHABLE as it is impossible to mark a lambda noreturn.
 */
#define MONGO_BASE_ASSERT_FAILED(fail_func, code, msg)                                    \
    do {                                                                                  \
        [&]() MONGO_COMPILER_COLD_FUNCTION {                                              \
            fail_func(::mongo::error_details::makeStatus(code, msg), __FILE__, __LINE__); \
        }();                                                                              \
        MONGO_COMPILER_UNREACHABLE;                                                       \
    } while (false)

#define MONGO_BASE_ASSERT(fail_func, code, msg, cond)       \
    do {                                                    \
        if (MONGO_unlikely(!(cond))) {                      \
            MONGO_BASE_ASSERT_FAILED(fail_func, code, msg); \
        }                                                   \
    } while (false)

/**
 * "user assert".  if asserts, user did something wrong, not our code.
 * On failure, throws an exception.
 */
#define uasserted(msgid, msg) MONGO_BASE_ASSERT_FAILED(::mongo::uassertedWithLocation, msgid, msg)
#define uassert(msgid, msg, expr) \
    MONGO_BASE_ASSERT(::mongo::uassertedWithLocation, msgid, msg, expr)

MONGO_COMPILER_NORETURN void uassertedWithLocation(const Status& status,
                                                   const char* file,
                                                   unsigned line);

#define uassertStatusOK(...) ::mongo::uassertStatusOKWithLocation(__VA_ARGS__, __FILE__, __LINE__)
inline void uassertStatusOKWithLocation(const Status& status, const char* file, unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        uassertedWithLocation(status, file, line);
    }
}

template <typename T>
inline T uassertStatusOKWithLocation(StatusWith<T> sw, const char* file, unsigned line) {
    uassertStatusOKWithLocation(sw.getStatus(), file, line);
    return std::move(sw.getValue());
}

/**
 * Like uassertStatusOK(status), but also takes an expression that evaluates to  something
 * convertible to std::string to add more context to error messages. This contextExpr is only
 * evaluated if the status is not OK.
 */
#define uassertStatusOKWithContext(status, contextExpr) \
    ::mongo::uassertStatusOKWithContextAndLocation(     \
        status, [&]() -> std::string { return (contextExpr); }, __FILE__, __LINE__)
template <typename ContextExpr>
inline void uassertStatusOKWithContextAndLocation(const Status& status,
                                                  ContextExpr&& contextExpr,
                                                  const char* file,
                                                  unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        uassertedWithLocation(
            status.withContext(std::forward<ContextExpr>(contextExpr)()), file, line);
    }
}

template <typename T, typename ContextExpr>
inline T uassertStatusOKWithContextAndLocation(StatusWith<T> sw,
                                               ContextExpr&& contextExpr,
                                               const char* file,
                                               unsigned line) {
    uassertStatusOKWithContextAndLocation(
        sw.getStatus(), std::forward<ContextExpr>(contextExpr), file, line);
    return std::move(sw.getValue());
}

/**
 * massert is like uassert but it logs the message before throwing.
 */
#define massert(msgid, msg, expr) \
    MONGO_BASE_ASSERT(::mongo::msgassertedWithLocation, msgid, msg, expr)

#define msgasserted(msgid, msg) \
    MONGO_BASE_ASSERT_FAILED(::mongo::msgassertedWithLocation, msgid, msg)
MONGO_COMPILER_NORETURN void msgassertedWithLocation(const Status& status,
                                                     const char* file,
                                                     unsigned line);

#define massertStatusOK(...) ::mongo::massertStatusOKWithLocation(__VA_ARGS__, __FILE__, __LINE__)
inline void massertStatusOKWithLocation(const Status& status, const char* file, unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        msgassertedWithLocation(status, file, line);
    }
}

/**
 * verify is deprecated. It is like invariant() in debug builds and massert() in release builds.
 */
#define verify(expression) MONGO_verify(expression)
#define MONGO_verify(_Expression)                                    \
    do {                                                             \
        if (MONGO_unlikely(!(_Expression))) {                        \
            ::mongo::verifyFailed(#_Expression, __FILE__, __LINE__); \
        }                                                            \
    } while (false)

inline void invariantWithLocation(const Status& status,
                                  const char* expr,
                                  const char* file,
                                  unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        ::mongo::invariantOKFailed(expr, status, file, line);
    }
}

template <typename T>
inline T invariantWithLocation(StatusWith<T> sw,
                               const char* expr,
                               const char* file,
                               unsigned line) {
    if (MONGO_unlikely(!sw.isOK())) {
        ::mongo::invariantOKFailed(expr, sw.getStatus(), file, line);
    }
    return std::move(sw.getValue());
}

template <typename ContextExpr>
inline void invariantWithContextAndLocation(const Status& status,
                                            const char* expr,
                                            ContextExpr&& contextExpr,
                                            const char* file,
                                            unsigned line) {
    if (MONGO_unlikely(!status.isOK())) {
        ::mongo::invariantOKFailedWithMsg(
            expr, status, std::forward<ContextExpr>(contextExpr)(), file, line);
    }
}

template <typename T, typename ContextExpr>
inline T invariantWithContextAndLocation(StatusWith<T> sw,
                                         const char* expr,
                                         ContextExpr&& contextExpr,
                                         const char* file,
                                         unsigned line) {
    if (MONGO_unlikely(!sw.isOK())) {
        ::mongo::invariantOKFailedWithMsg(expr, sw.getStatus(), contextExpr(), file, line);
    }
    return std::move(sw.getValue());
}

// some special ids that we want to duplicate

// > 10000 asserts
// < 10000 AssertionException

enum { ASSERT_ID_DUPKEY = 11000 };

std::string demangleName(const std::type_info& typeinfo);

/**
 * A utility function that converts an exception to a Status.
 * Only call this function when there is an active exception
 * (e.g. in a catch block).
 *
 * Note: this technique was created by Lisa Lippincott.
 *
 * Example usage:
 *
 *   Status myFunc() {
 *       try {
 *           funcThatThrows();
 *           return Status::OK();
 *       } catch (...) {
 *           return exceptionToStatus();
 *       }
 *   }
 */
Status exceptionToStatus() noexcept;

}  // namespace mongo

#define MONGO_ASSERT_ON_EXCEPTION(expression)                                         \
    try {                                                                             \
        expression;                                                                   \
    } catch (const std::exception& e) {                                               \
        std::stringstream ss;                                                         \
        ss << "caught exception: " << e.what() << ' ' << __FILE__ << ' ' << __LINE__; \
        msgasserted(13294, ss.str());                                                 \
    } catch (...) {                                                                   \
        massert(10437, "unknown exception", false);                                   \
    }

#define MONGO_ASSERT_ON_EXCEPTION_WITH_MSG(expression, msg)         \
    try {                                                           \
        expression;                                                 \
    } catch (const std::exception& e) {                             \
        std::stringstream ss;                                       \
        ss << msg << " caught exception exception: " << e.what();   \
        msgasserted(14043, ss.str());                               \
    } catch (...) {                                                 \
        msgasserted(14044, std::string("unknown exception") + msg); \
    }

/**
 * The purpose of this macro is to instruct the compiler that a line of code will never be reached.
 *
 * Example:
 *     // code above checks that expr can only be FOO or BAR
 *     switch (expr) {
 *     case FOO: { ... }
 *     case BAR: { ... }
 *     default:
 *         MONGO_UNREACHABLE;
 */

#define MONGO_UNREACHABLE ::mongo::invariantFailed("Hit a MONGO_UNREACHABLE!", __FILE__, __LINE__);