Alessandro Bonazzi
e075990ed3
Files correlati : Commento : Aggiunto il preprocessore c++ mcpp per sostituire il compilatore nella compilazione delle maschere.
62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
/* n_27.c: Rescanning of a macro replace any macro call in the replacement
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text after substitution of parameters by pre-expanded-arguments. This
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re-examination may involve the succeding sequences from the source
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file (what a queer thing!). */
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#include "defs.h"
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main( void)
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{
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int a = 1, b = 2, c, m = 1, n = 2;
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fputs( "started\n", stderr);
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/* 27.1: Cascaded use of object-like macros. */
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/* 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8; */
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#define NEST8 NEST7 + 8
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#define NEST7 NEST6 + 7
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#define NEST6 NEST5 + 6
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#define NEST5 NEST4 + 5
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#define NEST4 NEST3 + 4
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#define NEST3 NEST2 + 3
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#define NEST2 NEST1 + 2
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#define NEST1 1
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assert( NEST8 == 36);
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/* 27.2: Cascaded use of function-like macros. */
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/* (1) + (1 + 2) + 1 + 2 + 1 + 2 + 3 + 1 + 2 + 3 + 4; */
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#define FUNC4( a, b) FUNC3( a, b) + NEST4
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#define FUNC3( a, b) FUNC2( a, b) + NEST3
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#define FUNC2( a, b) FUNC1( a, b) + NEST2
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#define FUNC1( a, b) (a) + (b)
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assert( FUNC4( NEST1, NEST2) == 23);
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/* 27.3: An identifier generated by ## operator is subject to expansion. */
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#define glue( a, b) a ## b
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#define MACRO_1 1
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assert( glue( MACRO_, 1) == 1);
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#define sub( x, y) (x - y)
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#define head sub(
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#define math( op, a, b) op( (a), (b))
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/* 27.4: 'sub' as an argument of math() is not pre-expanded, since '(' is
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missing. */
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assert( math( sub, a, b) == -1);
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/* 27.5: Queer thing. */
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c = head a,b );
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assert( c == -1);
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/* 27.6: Recursive macro (the 2nd 'm' is expanded to 'n' since it is in
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source file). */
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#define m n
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#define n( a) a
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c = m( m);
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assert( c == 2);
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fputs( "success\n", stderr);
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return 0;
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}
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