ref: 4383318eabb50094a0aa325cf4efeea844eea051
dir: /sys/src/cmd/cpp/test/edges.in/
#define NOP(x) x
#define CAT(a, b) a ## b
#define EOF (-1)
-- test nop --
x NOP(CAT(foo, EOF)) y
x NOP(CAT(EOF, foo)) y
x CAT(, EOF) y
y CAT(foo,) x
x CAT(,foo) y
X NOP(CAT(,)) y
-- test ncat --
#define NCAT(a) foo ## a
NCAT(bar)
-- test xcat (no left arg) --
#define XCAT(a) ## a
foo XCAT(bar)
-- test cat3 --
#define CAT3(foo) a##foo##b
CAT3(blah)
-- test expand and cat --
#define BAR 3
#define FOO CAT(BAR, 3)
FOO
-- test expand and cat 2 --
/* Expected: a bc d */
CAT(a b, c d)
WUT
-- test varargs --
#define xprint(a, ...) print(a, __VA_ARGS__)
xprint("hi", "there")
xprint("hi")
-- test expanding commas --
#define C a,b
#define X(a) a
#define Y X(C)
Y
#define x 3
#define f(a) f(x * (a))
#undef x
#define x 2
#define g f
#define z z[0]
#define h g(~
#define m(a) a(w)
#define w 0,1
#define t(a) a
#define p() int
#define q(x) x
#define r(x,y) x ## y
#define str(x) # x
-- test complex expressions --
f(y+1) + f(f(z)) % t(t(g)(0) + t)(1);
g(x+(3,4)-w) | h 5) & m
(f)^m(m);
-- test empty args --
#define ZARGS(a) a b a
ZARGS()
-- test complex expressions with empty args --
p() i[q()] = { q(1), r(2,3), r(4,), r(,5), r(,) };
char c[2][6] = { str(hello), str() };