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The Vala Programming Language
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<h2>The Vala Programming Language</h2>
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<div class="paragraph">
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<p>Vala is a programming language mainly targeted at GNOME developers.</p>
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<div class="paragraph">
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<p>Its syntax is inspired by C# (and thus, indirectly, by Java). But
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unlike C# and Java, Vala does not attempt to provide memory safety:
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Vala is compiled to C, and the C code is compiled with GCC using
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typical compiler flags. Basic operations like integer arithmetic
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are directly mapped to C constructs. As a results, the
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recommendations in <a href="#chap-Defensive_Coding-C">[chap-Defensive_Coding-C]</a> apply.</p>
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<div class="paragraph">
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<p>In particular, the following Vala language constructs can result in
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undefined behavior at run time:</p>
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<div class="ulist">
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<ul>
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<li>
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<p>Integer arithmetic, as described in <a href="#sect-Defensive_Coding-C-Arithmetic">[sect-Defensive_Coding-C-Arithmetic]</a>.</p>
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</li>
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<li>
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<p>Pointer arithmetic, string subscripting and the
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<code>substring</code> method on strings (the
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<code>string</code> class in the
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<code>glib-2.0</code> package) are not range-checked. It
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is the responsibility of the calling code to ensure that the
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arguments being passed are valid. This applies even to cases
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(like <code>substring</code>) where the implementation
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would have range information to check the validity of indexes.
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See <a href="#sect-Defensive_Coding-C-Pointers">[sect-Defensive_Coding-C-Pointers]</a>.</p>
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</li>
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<li>
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<p>Similarly, Vala only performs garbage collection (through
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reference counting) for <code>GObject</code> values. For
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plain C pointers (such as strings), the programmer has to ensure
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that storage is deallocated once it is no longer needed (to
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avoid memory leaks), and that storage is not being deallocated
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while it is still being used (see <a href="#sect-Defensive_Coding-C-Use-After-Free">[sect-Defensive_Coding-C-Use-After-Free]</a>).</p>
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