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From: Nick Owens <mischief@offblast.org>
To: 9front@9front.org
Subject: bug: cpp(1) token pasting failure
Date: Sun, 16 Sep 2018 13:54:16 -0700	[thread overview]
Message-ID: <CAH_zEu5vejwg0OzoTGP-iz+f5+dhL42m=hzo5+tkM+T4KcUQGQ@mail.gmail.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 1100 bytes --]

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;
}

[-- Attachment #2: concat.c --]
[-- Type: text/x-csrc, Size: 356 bytes --]

#define DEF_ASM(x) DEF(TOK_ASM_ ## x, #x)
#define DEF_ASMTEST(x,suffix) \
 DEF_ASM(x ## o ## suffix)

enum token {
        TOK_NULL
#define DEF(id, str) ,id
DEF_ASMTEST(j,)
#undef DEF
};

static const char keywords[] =
#define DEF(id, str) str "\0"
DEF_ASMTEST(j,)
#undef DEF
;

#define DEF(id, str)

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

             reply	other threads:[~2018-09-16 20:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-16 20:54 Nick Owens [this message]
2018-09-17 10:17 ` [9front] " Ethan Gardener
2018-09-17 11:53   ` Nick Owens

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