28 lines
874 B
Text
28 lines
874 B
Text
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(* This test shows that the definition of BAR captures the original
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definition of FOO, so even if FOO is redefined, the expansion of
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BAR does not change. *)
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#define FOO "original definition"
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#define BAR FOO
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#undef FOO
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#define FOO "new definition"
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FOO (* expands to "new definition" *)
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BAR (* expands to "original definition" *)
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(* This test shows that a formal parameter can shadow a previously
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defined macro. *)
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#define F(FOO) FOO
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F(42) (* expands to 42 *)
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(* This test shows that two formal parameters can have the same
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name. In that case, the second parameter shadows the first one. *)
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#define G(X, X) X+X
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G(42,23) (* expands to 23+23 *)
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(* This test shows that it is OK to pass an empty argument to a macro
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that expects one parameter. This is interpreted as passing one
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empty argument. *)
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#define expect(x) show(x)
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expect(42)
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expect("23")
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expect()
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