22b4470f2a
Update all links to C++ Core Guidelines to `e49158a`.
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db76e34e74/personal/fred-tingaud/rspec/refresh-cppcoreguidelines.py
When re-using this script, be mindful that:
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Co-authored-by: Marco Borgeaud <marco.borgeaud@sonarsource.com>
46 lines
2.1 KiB
Plaintext
46 lines
2.1 KiB
Plaintext
== Why is this an issue?
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Throwing an exception from a destructor may result in a call to `std::terminate`.
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By default, compilers implicitly declare destructors as `noexcept`, so `std::terminate` is called when they exit with an exception.
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Destructors may still propagate an exception if they are explicitly declared as `noexcept(false)`.
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However, even a destructor declared as `noexcept(false)` calls `std::terminate` when it throws during stack unwinding.
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The following example illustrates the severity of the underlying problem:
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The destructor of a container needs to call the destructors for all managed objects.
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Suppose a call to an object's destructor throws an exception.
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In that case, there are only two _conceptual_ ways to proceed:
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1. Abort the destruction.
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This results in a partially destroyed object and possibly many more objects whose destructors are never called.
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2. Ignore the exception and proceed with destroying the remaining objects.
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However, this potentially results in more partially destroyed objects if further destructors throw an exception.
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Because both options are undesired, destructors should never `throw` exceptions.
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=== What is the potential impact?
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In most cases, throwing exceptions in destructors makes the program unreliable:
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* If `std::terminate` is called, the program terminates in an implementation-defined, abrupt, and unclean manner.
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* The program's behavior is undefined if a standard library component (a container, an algorithm, ...) manages a user-defined object that throws an exception from its destructor.
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include::{docdir}/how_to_fix_it.adoc[]
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== Resources
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=== Documentation
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include::{docdir}/documentation.adoc[]
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=== External coding guidelines
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* {cpp} Core Guidelines - https://github.com/isocpp/CppCoreGuidelines/blob/e49158a/CppCoreGuidelines.md#c36-a-destructor-must-not-fail[C.36: A destructor must not fail]
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* {cpp} Core Guidelines - https://github.com/isocpp/CppCoreGuidelines/blob/e49158a/CppCoreGuidelines.md#c37-make-destructors-noexcept[C.37: Make destructors `noexcept`]
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* MISRA {cpp}:2008, 15-5-1 - A class destructor shall not exit with an exception.
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=== Related rules
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include::{docdir}/related_rules.adoc[]
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