Raeburn@ATHENA.MIT.EDU (Ken Raeburn) (02/25/90)
(1.37, vax)
I think cpp is expanding the following code incorrectly:
/*
* test of cpp
*/
#include "./assert.h" /* running in 1.37 src directory */
#define A(X) (assert(X))
#define X1(X) (A(X), X.one)
#define X2(X) (A(X), X.two)
#define X3(X) (A(X), X.three)
#define X4(X) (A(X), X.four)
foo (X) {
return X4 (X3 (X2 (X1 (X))));
}
The output contains strings with `\' characters before double-quotes
only doubled, rather than tripled as would be necessary to get the
correct string values.
(In the original code, I wanted the pre-substitution text of the
argument in the string, obviously, but the macros I was writing were
evolving in the wrong direction.)
[multics!raeburn]
{/mit/gnu/dev/build/vax-gcc-1.37}
<1002 3:09am> % ./cpp -v foo.c
GNU CPP version 1.37
foo.c:14: only 2 args to macro `__assert'
foo.c:14: unterminated string or character constant
foo.c:0: unterminated macro call
foo.c:16: only 2 args to macro `__assert'
# 1 "foo.c"
# 1 "/mit/gnu/vaxlib/gcc-include/./assert.h" 1
void __eprintf ();
void abort();
# 5 "foo.c" 2
foo (X) {
return ((((((((((((((((X) ? 0 : (__eprintf ("Failed assertion " "X" " at line %d of `" "foo.c" "'.\n", 14), abort ()) ) ) , X.one) ) ? 0 : (__eprintf ("Failed assertion " "((((X) ? 0 : (__eprintf (\"Failed assertion \" \"X\" \" at line %d of `\" \"foo.c\" \"'.\\n\", 14), abort ()))), X.one)" " at line %d of `" "foo.c" "'.\n", 14), abort ()) ) ) , ((((X) ? 0 : (__eprintf ("Failed assertion " "X" " at line %d of `" "foo.c" "'.\n", 14), abort ()) ) ) , X.one) .two) )
? 0 : (__eprintf ("Failed assertion " "((((((((X) ? 0 : (__eprintf (\"Failed assertion \" \"X\" \" at line %d of `\" \"foo.c\" \"'.\\n\", 14), abort ()))), X.one)) ? 0 : (__eprintf (\"Failed assertion \" \"((((X) ? 0 : (__eprintf (\\"Failed assertion \\" \\"X\\" \\" at line %d of `\\" \\"foo.c\\" \\"'.\\\\n\\\", 14), abort ()))), X.one)\" \" at line %d of `\" \"foo.c\" \"'.\\n\" " at line %d of `" 14 "'.\n", ), abort ()) , abort ())))) ? 0 : (__eprintf ("Failed as!
sertion " "((((((((((((X) ? 0 : (_
_eprintf (\"Failed assertion \" \"X\" \" at line %d of `\" \"foo.c\" \"'.\\n\", 14), abort ()))), X.one)) ? 0 : (__eprintf (\"Failed assertion \" \"((((X) ? 0 : (__eprintf (\\"Failed assertion \\" \\"X\\" \\" at line %d of `\\" \\"foo.c\\" \\"'.\\\\n\\\", 14), abort ()))), X.one)\" \" at line %d of `\" \"foo.c\" \"'.\\n\" " at line %d of `" 14 "'.\n", ), abort ()) , abort ()))), ((((X) ? 0 : (__eprintf (\"Failed assertion \" \"X\" \" at line %d of `\" \"foo.c\" \"'.\\n\", 14), abort ()))), X.on
e).two)) ? 0 : (__eprintf (\"Failed assertion \" \"((((((((X) ? 0 : (__eprintf (\\"Failed assertion \\" \\"X\\" \\" at line %d of `\\" \\"foo.c\\" \\"'.\\\\n\\\", 14), abort ()))), X.one)) ? 0 : (__eprintf (\\\"Failed assertion \\\" \\\"((((X) ? 0 : (__eprintf (\\\\\"Failed assertion \\\\\" \\\"X\\\\\" \\\" at line %d of `\\\\\" \\\"foo.c\\\\\" \\\"'.\\\\\\\\n\\\\\\\", 14), abort ()))), X.one)\\\" \\\" at line %d of `\\\" \\\"foo.c\\\" \\\"'.\\n\\" \" at line %d of `\" 14 \!
"'.\\n\", ), abort ()), abort ()))
)", "foo.c", 16)) ) Exit 33 ./cpp -v foo.c
[multics!raeburn]
{/mit/gnu/dev/build/vax-gcc-1.37}
<1003 3:09am> % exit
[multics!raeburn]
{/mit/gnu/dev/build/vax-gcc-1.37}
<1004 3:10am> %
script done on Sun Feb 25 03:10:06 1990Raeburn@ATHENA.MIT.EDU (Ken Raeburn) (02/25/90)
I didn't notice before sending in my last report, but the assert.h
that was being used was from a previous gcc release. (The directory I
was in had only my gcc object files, not sources and header files.)
Here's the header file I was really using:
/* Allow this file to be included multiple times
with different settings of NDEBUG. */
#undef assert
#undef __assert
#ifdef NDEBUG
#define assert(ignore)
#else
#define assert(expression) \
((expression) ? 0 : __assert (#expression, __FILE__, __LINE__))
void __eprintf (); /* Defined in gnulib */
#ifdef __GNUC__
volatile void abort();
#else
void abort();
#endif
#ifdef __STDC__
#define __assert(expression, file, line) \
(__eprintf ("Failed assertion " expression \
" at line %d of `" file "'.\n", line), \
abort ())
#else /* no __STDC__; i.e. -traditional. */
#define __assert(expression, file, line) \
(__eprintf ("Failed assertion at line %d of `%s'.\n", line, file), \
abort ())
#endif /* no __STDC__; i.e. -traditional. */
#endif
This doesn't change the fact that the expansion seems incorrect.
Also, some line breaks appear to have been added by my local mailer;
the big ugly expression really was all one line.
-- Ken