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6496bf8c1d
The gboolean type of GLib (a widely used C library) is a typedef to int. It is meant to represent a simple true/false value. Resolves #7491
38 lines
1.5 KiB
Plaintext
38 lines
1.5 KiB
Plaintext
/**
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* @name Ambiguously signed bit-field member
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* @description Bit fields with integral types should have explicit signedness
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* only. For example, use `unsigned int` rather than `int`. It is
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* implementation specific whether an `int`-typed bit field is
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* signed, so there could be unexpected sign extension or
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* overflow.
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* @kind problem
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* @problem.severity warning
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* @precision high
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* @id cpp/ambiguously-signed-bit-field
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* @tags reliability
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* readability
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* language-features
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* external/cwe/cwe-190
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*/
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import cpp
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from BitField bf
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where
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not bf.getUnspecifiedType().(IntegralType).isExplicitlySigned() and
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not bf.getUnspecifiedType().(IntegralType).isExplicitlyUnsigned() and
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not bf.getUnspecifiedType() instanceof Enum and
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not bf.getUnspecifiedType() instanceof BoolType and
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// At least for C programs on Windows, BOOL is a common typedef for a type
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// representing BoolType.
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not bf.getType().hasName("BOOL") and
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// GLib's gboolean is a typedef for a type representing BoolType.
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not bf.getType().hasName("gboolean") and
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// If this is true, then there cannot be unsigned sign extension or overflow.
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not bf.getDeclaredNumBits() = bf.getType().getSize() * 8 and
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not bf.isAnonymous() and
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not bf.isFromUninstantiatedTemplate(_)
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select bf,
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"Bit field " + bf.getName() + " of type " + bf.getUnderlyingType().getName() +
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" should have explicitly unsigned integral, explicitly signed integral, or enumeration type."
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