Assertions

A line of the form:

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#assert predicate (token-sequence) 

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associates the token-sequence with the predicate in the assertion name space (separate from the space used for macro definitions). The predicate must be an identifier token.

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#assert predicate 

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asserts that predicate exists, but does not associate any token sequence with it.

The compiler provides the following predefined predicates by default (not in -Xc mode):

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#assert
system (unix)
#assert machine (sparc)(SPARC)
#assert machine (i386)(Intel)
#assert cpu (sparc)(SPARC)
#assert cpu (i386)(Intel)

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lint provides the following predefinition predicate by default (not in -Xc mode):

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#assert lint (on)

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Any assertion may be removed by using #unassert, which uses the same syntax as assert. Using #unassert with no argument deletes all assertions on the predicate; specifying an assertion deletes only that assertion.

An assertion may be tested in a #if statement with the following syntax:

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#if #predicate(non-empty token-list) 

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For example, the predefined predicate system can be tested with the following line:

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#if #system(unix) 

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which evaluates true.