Re: bug in C preprocessor

[Dave Brolley <brolley at cygnus dot com>]

Tom,

The Phases of Translation in the standard (section 2.1) make it clear that the
entire program is decomposed into preprocessing tokens in phase 3 and
preprocessing directives are interpreted in phase 4, so while the code in the
FALSE path of the conditional compilation does not get interpreted, it does
still get broken up into preprocessing tokens. The unterminated literal is an
error detected during that process.

Dave

Tom Williams wrote:

> Hello.  I'm having a problem with the C preprocessor not handling a
> "#ifdef" correctly.
>
> GCC Version: 2.95.1
> Host system: AIX 4.3.1
> Compiler command line: gcc test.c -o test
> error message:
> In file included from test.c:2:
> test.h:2: unterminated string or character constant
>
> If I use the following command line, my program compiles just fine: gcc
> -trigraphs test.c -o test
>
> I believe my program shoud be able to compile without having to specify
> "-trigraphs" because the trigraph is in a #ifdef block for a platform that
> is *not* defined.
>
> Thanks in advance for your time!
>
> Peace....
>
> Tom Williams
> tom.williams@diversifiedsoftware.com
>
> Here is test.c:
>
> #include <stdio.h>
> #include "test.h"
>
> int main(int argc, char **argv)
> {
>      puts("Hello World!");
>      return 0;
> }
>
> Here is test.h:
>
> #if defined (__MVS__)
> #define XOR ??'
> #else
> #define XOR ^
> #endif // __MVS__
>
> Here is test.i:
>
> # 1 "test.c"
> # 1
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  1 3
>
> # 1
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdarg.h
> " 1 3
>
> typedef char *__gnuc_va_list;
>
> # 122
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdarg.h
> " 3
>
> # 209
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdarg.h
> " 3
>
> # 2
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> # 34
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  3
>
> # 1 "/usr/include/standards.h" 1 3
>
> # 98 "/usr/include/standards.h" 3
>
> # 45
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> typedef unsigned long    size_t;
>
> typedef long   fpos_t;
>
> typedef long long fpos64_t;
>
> typedef struct {
>      unsigned char  *_ptr;
>      int  _cnt;
>      unsigned char  *_base;
>      unsigned char   *_bufendp;
>      short     _flag;
>      short     _file;
>      int  __stdioid;
>      char *__newbase;
>
>      long _unused[1];
>
> } FILE;
>
> extern FILE    _iob[16 ];
>
> extern size_t  fread(void *, size_t, size_t, FILE *);
> extern size_t  fwrite(const void *, size_t, size_t,FILE *);
>
> # 220
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  3
>
> extern int     __flsbuf(unsigned char, FILE *);
> extern int     __filbuf(FILE *);
> extern int     ferror(FILE *);
> extern int     feof(FILE *);
> extern void    clearerr(FILE *);
> extern int     putchar(int);
> extern int     getchar(void);
> extern int     putc(int, FILE *);
> extern int     getc(FILE *);
> extern int     remove(const char *);
> extern int     rename(const char *, const char *);
> extern FILE    *tmpfile(void);
> extern char    *tmpnam(char *);
> extern int     fclose(FILE *);
> extern int     fflush(FILE *);
> extern FILE    *fopen(const char *, const char *);
> extern FILE    *freopen(const char *, const char *, FILE *);
> extern void    setbuf(FILE *, char *);
> extern int     setvbuf(FILE *, char *, int, size_t);
> extern int     fprintf(FILE *, const char *, ...);
> extern int     fscanf(FILE *, const char *, ...);
> extern int     printf(const char *, ...);
> extern int     scanf(const char *, ...);
> extern int     sprintf(char *, const char *, ...);
>
> extern int     snprintf(char *, size_t, const char *, ...);
>
> extern int     sscanf(const char *, const char *, ...);
>
> # 1 "/usr/include/va_list.h" 1 3
>
> # 33 "/usr/include/va_list.h" 3
>
> typedef   char *va_list;
>
> # 72 "/usr/include/va_list.h" 3
>
> # 260
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> extern int     vfprintf(FILE *, const char *, __gnuc_va_list);
> extern int     vprintf(const char *, __gnuc_va_list);
> extern int     vsprintf(char *, const char *, __gnuc_va_list);
>
> extern int     vsnprintf(char *, size_t, const char *, __gnuc_va_list);
>
> extern int     fgetc(FILE *);
> extern char    *fgets(char *, int, FILE *);
> extern int     fputc(int, FILE *);
> extern int     fputs(const char *, FILE *);
> extern char    *gets(char *);
> extern int     puts(const char *);
> extern int     ungetc(int, FILE *);
> extern int     fgetpos(FILE *, fpos_t *);
> extern int     fseek(FILE *, long int, int);
> extern int     fsetpos(FILE *, const fpos_t *);
> extern long    ftell(FILE *);
> extern void    rewind(FILE *);
> extern void    perror(const char *);
>
> extern int     getc_unlocked(FILE *);
> extern int     getchar_unlocked(void);
> extern int     putc_unlocked(int, FILE *);
> extern int     putchar_unlocked(int);
>
> # 338
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  3
>
> # 1
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 1 3
>
> # 1 "/usr/include/sys/inttypes.h" 1 3
>
> typedef signed char      int8_t;
> typedef signed short          int16_t;
> typedef signed int       int32_t;
>
> typedef   signed long long    int64_t;
>
> typedef unsigned char         uint8_t;
> typedef unsigned short        uint16_t;
> typedef unsigned int          uint32_t;
>
> typedef unsigned long long    uint64_t;
>
> typedef int64_t               intmax_t;
> typedef uint64_t         uintmax_t;
>
> typedef signed long      intptr_t;
> typedef unsigned long         uintptr_t;
>
> typedef signed char      int_least8_t;
> typedef signed short          int_least16_t;
> typedef signed int       int_least32_t;
>
> typedef signed long long int_least64_t;
>
> typedef unsigned char         uint_least8_t;
> typedef unsigned short        uint_least16_t;
> typedef unsigned int          uint_least32_t;
>
> typedef unsigned long long    uint_least64_t;
>
> typedef int32_t     intfast_t;
> typedef uint32_t    uintfast_t;
>
> typedef signed char int_fast8_t;
> typedef int32_t          int_fast16_t;
> typedef int32_t          int_fast32_t;
> typedef uint32_t    uint_fast8_t;
> typedef uint32_t    uint_fast16_t;
> typedef uint32_t    uint_fast32_t;
>
> typedef int64_t          int_fast64_t;
> typedef uint64_t    uint_fast64_t;
>
> typedef signed long __long32_t;
> typedef unsigned long    __ulong32_t;
>
> typedef signed char      int8;
> typedef signed short          int16;
> typedef signed int       int32;
>
> typedef   signed long long    int64;
>
> typedef unsigned char         u_int8;
> typedef unsigned char         u_int8_t;
> typedef unsigned short        u_int16;
> typedef unsigned short        u_int16_t;
> typedef unsigned int          u_int32;
> typedef unsigned int          u_int32_t;
>
> typedef unsigned long long    u_int64;
> typedef unsigned long long    u_int64_t;
>
> # 37
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 2 3
>
> typedef long int ptrdiff_t;
>
> typedef short unsigned int wchar_t;
>
> typedef unsigned int     wctype_t;
>
> # 92
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> typedef   int       time_t;
>
> typedef int         clock_t;
>
> # 113
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> typedef   unsigned char  uchar_t;
> typedef   unsigned short ushort_t;
> typedef   unsigned int   uint_t;
> typedef unsigned long    ulong_t;
> typedef signed long ssize_t;
>
> typedef int         level_t;
> typedef   int       daddr_t;
> typedef   char *         caddr_t;
> typedef   unsigned int   ino_t;
> typedef short       cnt_t;
> typedef unsigned int     dev_t;
> typedef   int       chan_t;
>
> typedef int soff_t;
>
> typedef long        off_t;
>
> typedef long long   off64_t;
>
> typedef   long      paddr_t;
> typedef   int       key_t;
> typedef int         timer_t;
> typedef   short          nlink_t;
> typedef   uint_t         mode_t;
> typedef uint_t      uid_t;
> typedef uint_t      gid_t;
> typedef   void *         mid_t;
> typedef   int       pid_t;
> typedef int             tid_t;
> typedef char        slab_t[12];
> typedef long        mtyp_t;
> typedef int             boolean_t;
>
> typedef int         blkcnt_t;
> typedef int         blksize_t;
>
> typedef ulong_t     fsblkcnt_t;
> typedef ulong_t          fsfilcnt_t;
>
>      typedef   int       wint_t;
>
> typedef uint_t      id_t;
> typedef unsigned int     useconds_t;
> typedef signed   int     suseconds_t;
> typedef int         clockid_t;
>
> typedef struct sigset_t  {
>
>      unsigned int losigs;
>      unsigned int hisigs;
>
> } sigset_t;
>
> typedef int signal_t;
>
> typedef struct fsid_t {
>
>      unsigned int val[2];
>
> } fsid_t;
>
> typedef struct __ptq_queue {
>      struct __ptq_queue  *__ptq_next;
>      struct __ptq_queue  *__ptq_prev;
> } __ptq_queue;
>
> typedef int __ptlock_type;
>
> typedef struct __pt_attr *pthread_attr_t;
> typedef   struct __pt_attr *pthread_condattr_t;
> typedef   struct __pt_attr *pthread_mutexattr_t;
>
> typedef   struct __pt_attr *pthread_rwlockattr_t;
>
> typedef unsigned int pthread_t;
> typedef unsigned int pthread_key_t;
>
> # 261
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> typedef struct {
>         __ptq_queue *   __ptq_link;
>         int             __reserved1;
>         __ptlock_type   __ptmtx_lock;
>         int             __ptmtx_flags;
>         pthread_t       __ptmtx_owner;
>         int             __mtx_id;
>         int             __acquisitions;
>         int             __mtx_kind;
>         int             __lock_cpt;
>         int             __sleeps;
>         int             __misses;
>         int             __reserved2;
>         unsigned long   __ptmtx_dbx;
> } pthread_mutex_t;
>
> typedef struct {
>         unsigned long   __ptcv_dbx;
>         int             __reserved1;
>         __ptlock_type   __ptcv_lock;
>         int             __ptcv_flags;
>         __ptq_queue *   __ptcv_waiters;
>         int             __reserved2;
>         int             __cv_id;
>         pthread_mutex_t *__cv_mutex;
>         int             __reserved3;
>         int             __cptwait;
>         int             __reserved;
>
> } pthread_cond_t;
>
> typedef struct {
>      __ptlock_type  __ptonce_lock;
>      int       __ptonce_initialized;
>      int       __ptonce_executing;
>      int       __ptonce_completed;
>      pthread_mutex_t     __ptonce_mutex;
>      pthread_cond_t __ptonce_executed;
> } pthread_once_t;
>
> typedef struct {
>
>         int             __pad;
>         unsigned long   __ptrlock_dbx;
>
>         pthread_mutex_t __rwl_mutex;
>         pthread_cond_t  __rwl_rsleepers;
>         pthread_cond_t  __rwl_wsleepers;
>         int             __rwl_flags;
>         pthread_t       __rwl_owner;
>         int             __rwl_rwlock_id;
>         int             __rwl_lock_count;
>
>         int             __rwl_waiting;
>         int             __rwl_wacquisitions;
>         int             __rwl_racquisitions;
>         int             __rwl_wsleeps;
>         int             __rwl_rsleeps;
>         unsigned long   __reserved[6];
> } pthread_rwlock_t;
>
> typedef void * __ptr32;
>
> # 1 "/usr/include/sys/m_types.h" 1 3
>
> typedef struct
>
> label_t
>
> {
>
>      struct label_t   *prev;
>      ulong_t           iar;
>      ulong_t           stack;
>      ulong_t           toc;
>      ulong_t           cr;
>      ulong_t           intpri;
>      ulong_t           reg[19];
> # 66 "/usr/include/sys/m_types.h" 3
>
> } label_t;
>
> typedef __long32_t  vmid_t;
> typedef __ulong32_t vmhandle_t;
>
> typedef struct
>
> vmaddr_t
>
> {
>
>      vmhandle_t     srval;
>      caddr_t        offset;
>
> } vmaddr_t;
>
> typedef struct
>
> adspace_t
>
> {
>
>      __ulong32_t    alloc;
>      vmhandle_t     srval[16];
>
> } adspace_t;
>
> # 346
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 2 3
>
> # 373
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> typedef ushort_t    UniChar;
>
> typedef   uchar_t        uchar;
> typedef   ushort_t  ushort;
> typedef   uint_t         uint;
> typedef ulong_t          ulong;
>
> typedef   struct { int r[1]; } *   physadr_t;
> typedef   physadr_t physadr;
>
> typedef   unsigned char  u_char;
> typedef   unsigned short u_short;
> typedef   unsigned int   u_int;
> typedef   unsigned long  u_long;
>
> typedef   struct    _quad { int val[2]; } quad;
> typedef   int  swblk_t;
>
> struct sigset  {
>      unsigned int losigs;
>      unsigned int hisigs;
> };
>
> struct fsid {
>      unsigned int   val[2];
> };
>
> struct fileid {
>      uint_t    fid_len;
>      ino_t     fid_ino;
>      uint_t    fid_gen;
>      char fid_x[(32  - sizeof(fsid_t) - sizeof(uint_t))  - (sizeof(ino_t) +
>  2) - sizeof(uint_t)];
> };
>
> # 439
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> struct fid {
>      uint_t    fid_len;
>      char fid_data[(32  - sizeof(fsid_t) - sizeof(uint_t)) ];
> };
> typedef struct fid fid_t;
>
> struct fhandle {
>      char x[32 ];
> };
> typedef struct fhandle fhandle_t;
>
> struct filehandle {
>      fsid_t         fh_fsid;
>      struct fileid  fh_fid;
> };
>
> struct unique_id {
>
>        unsigned long word1;
>        unsigned long word2;
>        unsigned long word3;
>        unsigned long word4;
>
> };
> typedef struct unique_id unique_id_t;
>
> # 500
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/sys/type
> s.h" 3
>
> typedef   long long  offset_t;
>
> typedef unsigned long long size64_t;
> typedef long long ssize64_t;
>
> typedef long long longlong_t;
> typedef unsigned long long u_longlong_t;
>
> # 365
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> extern int     fileno(FILE *);
> extern FILE    *fdopen(int,const char *);
> extern char    *ctermid(char *);
>
> extern void    flockfile(FILE *);
> extern void    funlockfile(FILE *);
> extern int     fseeko(FILE *, off_t, int);
> extern off_t   ftello(FILE *);
> extern int     ftrylockfile(FILE *);
> extern void    funlockfile(FILE *);
>
> # 1 "/usr/include/va_list.h" 1 3
>
> # 33 "/usr/include/va_list.h" 3
>
> # 72 "/usr/include/va_list.h" 3
>
> # 398
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> extern    char *optarg;
> extern    int  opterr;
> extern    int  optind;
> extern    int  optopt;
>
> # 415
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  3
>
> extern int     getw(FILE *);
> extern int     putw(int, FILE *);
> extern char    *tempnam(const char*, const char*);
> extern FILE    *popen(const char *, const char *);
> extern int     pclose(FILE *);
> extern int     getopt(int, char * const [], const char*);
> extern char    *cuserid(char *);
>
> # 1 "/usr/include/sys/limits.h" 1 3
>
> # 1 "/usr/include/float.h" 1 3
>
> # 176 "/usr/include/float.h" 3
>
>      extern  unsigned   int SINFINITY;
>      extern  unsigned   int _DBLINF[2];
>      extern  unsigned   int SQNAN;
>      extern  unsigned   int DQNAN[2];
>      extern  unsigned   int SSNAN;
>      extern  unsigned   int DSNAN[2];
>
> typedef   unsigned short fprnd_t;
>
> fprnd_t fp_read_rnd(void);
> fprnd_t fp_swap_rnd(fprnd_t rnd);
>
> # 231 "/usr/include/sys/limits.h" 2 3
>
> # 262 "/usr/include/sys/limits.h" 3
>
> # 432
> "/usr/local/egcs/lib/gcc-lib/powerpc-ibm-aix4.3.1.0/2.95.1/include/stdio.h"
>  2 3
>
> extern int fgetpos64(FILE *, fpos64_t *);
> extern FILE *fopen64(const char *, const char *);
> extern FILE *freopen64(const char *, const char *, FILE *);
> extern int fseeko64(FILE *, off64_t, int);
> extern int fsetpos64(FILE *, const fpos64_t *);
> extern off64_t ftello64(FILE *);
>
> extern void setbuffer(FILE *, char *, size_t);
> extern void setlinebuf(FILE *);
>
> # 1 "test.c" 2
>
> # 1 "test.h" 1
>
> # 2 "test.c" 2
>
> int main(int argc, char **argv)
> {
>      puts("Hello World!");
>      return 0;
> }