71 lines
1.7 KiB
Plaintext
71 lines
1.7 KiB
Plaintext
== Why is this an issue?
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The values that can be represented by a signed bit field with a length of one bit may not meet developer expectations. For example, according to the C99 Standard, a single-bit signed bit-field has a single (one) sign bit and no (zero) value bits.
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This rule does not apply to unnamed bit fields, as their values cannot be accessed.
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=== Noncompliant code example
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[source,cpp]
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----
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signed int f:1; // Noncompliant; there's only room here for the sign
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----
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=== Compliant solution
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[source,cpp]
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----
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unsigned int f:1;
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----
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or
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[source,cpp]
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----
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signed int:1; // unnamed
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----
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or
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[source,cpp]
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----
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signed int f:2;
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----
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== Resources
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* MISRA C:2004, 6.5 - Bit fields of type signed int shall be at least 2 bits long
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* MISRA C:2012, 6.2 - Single-bit named bit fields shall not be of a signed type
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* MISRA {cpp}:2008, 9-6-4 - Named bit-fields with signed integer type shall have a length of more than one bit
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Review "X" declaration sign and size.
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'''
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== Comments And Links
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(visible only on this page)
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=== is duplicated by: S1010
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=== on 9 Dec 2014, 20:58:20 Evgeny Mandrikov wrote:
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\[~ann.campbell.2] could you please verify this description, which was built as a combination of MISRA C:2012 and MISRA {cpp}2008?
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=== on 14 Dec 2014, 22:51:08 Evgeny Mandrikov wrote:
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\[~ann.campbell.2] I was expecting that you'll also specify SQALE model and other parameters, but ok...
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=== on 15 Dec 2014, 14:58:47 Ann Campbell wrote:
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Sorry [~evgeny.mandrikov], I didn't notice the lack of SQALE &etc. I'll pay more attention next time.
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endif::env-github,rspecator-view[]
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