Details
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Bug
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Status: Closed (View Workflow)
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Minor
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Resolution: Fixed
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5.5.37, 10.0.11, 10.1.0
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None
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None
Description
Leaving variables uninitialized in certain cases helps to achieve top-notch performance. Sometimes compiler thinks that variable may be used uninitialized (whereas it may not) and emits a warning.
To silence these warnings there is UNINIT_VAR() macro:
#if defined(_lint) || defined(FORCE_INIT_OF_VARS) || \
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defined(__cplusplus) || !defined(__GNUC__)
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#define UNINIT_VAR(x) x= 0
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#else
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/* GCC specific self-initialization which inhibits the warning. */
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#define UNINIT_VAR(x) x= x
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#endif
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There are a few problems with this macro:
1. It always emits "x= 0" for non-gcc
2. It always emits "x= 0" for C++ code
It means leaving variable uninitialized makes sense only in C code compiled by gcc.
Regarding __cplusplus: there is a reference to gcc bug which was fixed 3 years ago. Probably it is time to remove it?
Attachments
Issue Links
- relates to
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MDEV-6650 LINT_INIT emits code in non-debug builds
- Closed