gcc: Weak Pragmas

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1 6.61.11 Weak Pragmas
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1 For compatibility with SVR4, GCC supports a set of '#pragma' directives
1 for declaring symbols to be weak, and defining weak aliases.
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1 '#pragma weak SYMBOL'
1      This pragma declares SYMBOL to be weak, as if the declaration had
1      the attribute of the same name.  The pragma may appear before or
1      after the declaration of SYMBOL.  It is not an error for SYMBOL to
1      never be defined at all.
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1 '#pragma weak SYMBOL1 = SYMBOL2'
1      This pragma declares SYMBOL1 to be a weak alias of SYMBOL2.  It is
1      an error if SYMBOL2 is not defined in the current translation unit.
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