the attached C program will fail to be preprocessed by cpp(1) with the
following output. for comparison, the gcc -E test.c output follows as
well. this specific example was extracted from tinycc.

9front cpp(1):
term% cpp concat.c
cpp: concat.c:8 Bad token jo) produced by ##
cpp: concat.c:8 No newline at end of file
cpp: concat.c:8 EOF in macro arglist
cpp: concat.c:8 Disagreement in number of macro arguments
#line 1 "/usr/glenda/code/c/trash/concat.c"


#line 4 "/usr/glenda/code/c/trash/concat.c"

enum token {
        TOK_NULL

 DEF_ASM(jo #undef DEF};static const char keywords[] = #define DEF(id,
str) str "\0" DEF_ASMTEST(j,)#undef DEF;int main(int argc, char
*argv[]){        return -1;}#line 23
"/usr/glenda/code/c/trash/concat.c"

gcc -E:
mischief@omicron:/tmp $ gcc -E concat.c
# 1 "concat.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 31 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 32 "<command-line>" 2
# 1 "concat.c"




enum token {
        TOK_NULL

,TOK_ASM_jo

};

static const char keywords[] =

"jo" "\0"

;



int
main(int argc, char *argv[])
{
        return 0;
}