minix3/commands/ifdef/ifdef.c

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2020-02-21 00:59:27 +05:30
/* ifdef - remove #ifdefs Author: Warren Toomey */
/* Copyright 1989 by Warren Toomey wkt@cs.adfa.oz.au[@uunet.uu.net]
*
* You may freely copy or distribute this code as long as this notice
* remains intact.
*
* You may modify this code, as long as this notice remains intact, and
* you add another notice indicating that the code has been modified.
*
* You may NOT sell this code or in any way profit from this code without
* prior agreement from the author.
*/
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
/* Definition of structures and constants used in ifdef.c */
/* Types of symbols */
#define DEF 1 /* Symbol is defined */
#define UNDEF 2 /* Symbol isn't defined */
#define IGN 3 /* Ignore this symbol unless defined */
/* Redef mode values */
#define MUTABLE 1 /* Symbol can change defined <-> undefined */
#define IMMUTABLE 2 /* Symbol can't change as above */
/* Processing modes */
#define NO 0 /* Don't process */
#define YES 1 /* Process */
/* Ignore (IGN), ignore but process */
struct DEFINE {
char *symbol; /* SLL of defined symbols. The redef */
char type; /* field indicates if this symbol can */
char redef; /* change from defined <-> undefined. */
struct DEFINE *next; /* Type is DEF or UNDEF. */
};
/* Global variables & structures */
FILE *zin; /* Input file for processing */
struct DEFINE *defptr; /* Defined symbols SLL */
struct DEFINE *defend; /* Ptr to last node in defptr */
struct DEFINE *deftemp; /* Ptr to last found node */
int line = 1; /* Current line number */
int table = 0; /* Don't normally want a table */
extern int optind;
extern char *optarg;
/* Prototypes. */
int main(int argc, char **argv);
char fgetarg(FILE *stream, char *cbuf);
int find(char *symd);
void defit(char *sym, int redef, int typed);
void stop(void);
void gotoeoln(void);
void prteoln(void);
void printtable(void);
char getendif(void);
void gettable(void);
void parse(void);
void usage(void);
#ifdef __STDC__
char fgetarg ( FILE *stream , char *cbuf )
#else
char fgetarg(stream, cbuf) /* Get next arg from file into cbuf, */
FILE *stream; /* returning the character that */
char *cbuf; /* terminated it. Cbuf returns 0 */
#endif
{ /* if no arg. EOF is returned if no */
int ch; /* args left in file. */
int i;
i = 0;
cbuf[i] = 0;
while (((ch = fgetc(stream)) == ' ') || (ch == '\t') || (ch == '\n'))
if (ch == '\n') return(ch); /* Bypass leading */
/* Whitespace */
if (feof(stream)) return(EOF);
cbuf[i++] = ch;
while (((ch = fgetc(stream)) != ' ') && (ch != '\t') && (ch != '\n'))
cbuf[i++] = ch; /* Get the argument */
cbuf[i] = 0;
return(ch);
}
#ifdef __STDC__
int find ( char *sym )
#else
int find(sym)
char *sym;
#endif
{ /* Return DEF if defined else UNDEF */
deftemp = defptr;
while (deftemp) { /* Search for the symbol */
if (!strcmp(deftemp->symbol, sym))
return(deftemp->type); /* Setting up the type */
deftemp = deftemp->next;
}
return(0);
}
#define Define(x,y) defit(x,y,DEF)
#define Undefine(x,y) defit(x,y,UNDEF)
#define Ignore(x,y) defit(x,y,IGN)
#ifdef __STDC__
void defit ( char *sym , int redef , int type )
#else
void defit(sym, redef, type) /* Add symbol to the define list */
char *sym;
char redef; /* Mode: MUTABLE etc */
char type; /* Type: DEF, UNDEF, IGN */
#endif
{
struct DEFINE *temp;
char c;
c = find(sym); /* First try finding the symbol */
if (type == c) return; /* Return if already declared */
if (c) { /* We have to move if from DEF <-> UNDEF */
if (deftemp->redef == IMMUTABLE)
return;
else {
deftemp->type = type;
deftemp->redef = redef;
}
} else { /* We must create a struct & add it */
/* Malloc room for the struct */
if ((temp = (struct DEFINE *)malloc(sizeof(struct DEFINE))) == NULL) {
(void)fprintf(stderr, "ifdef: could not malloc\n");
exit(1);
}
/* Malloc room for symbol */
if ((temp->symbol = (char *)malloc(strlen(sym) + 1)) == NULL) {
(void)fprintf(stderr, "ifdef: could not malloc\n");
exit(1);
}
(void)strcpy(temp->symbol, sym); /* Copy symbol into struct */
temp->redef = redef; /* and set its redef mode too */
temp->type = type; /* as well as making it defined */
/* Now add to the SLL */
if (defptr == NULL) /* If first node set */
defptr = temp; /* the pointers to it */
else
defend->next = temp; /* else add it to the */
defend = temp; /* end of the list. */
}
}
#ifdef __STDC__
void stop ( void )
#else
void stop()
#endif
{ /* Stop: Tidy up at EOF */
if (table) printtable();
(void)fclose(zin);
exit(0);
}
#define Goto { line++; if (ch!='\n') gotoeoln(); }
#define Print { line++; if (ch!='\n') prteoln(); }
#ifdef __STDC__
void gotoeoln ( void )
#else
void gotoeoln() /* Go to the end of the line */
#endif
{
int ch;
while ((ch = fgetc(zin)) != '\n')
if (ch == EOF) stop();
}
#ifdef __STDC__
void prteoln ( void )
#else
void prteoln() /* Print to the end of the line */
#endif
{
int ch;
while ((ch = fgetc(zin)) != '\n')
if (ch == EOF)
stop();
else
(void)putchar(ch);
(void)putchar('\n');
}
#ifdef __STDC__
void printtable ( void )
#else
void printtable() /* Print the defines in the SLL */
#endif
{
struct DEFINE *temp;
(void)printf("Defined\n\n");
temp = defptr;
while (temp) {
if (temp->type == DEF) (void)printf("%s\n", temp->symbol);
temp = temp->next;
}
(void)printf("\n\nUndefined\n\n");
temp = defptr;
while (temp) {
if (temp->type == UNDEF) (void)printf("%s\n", temp->symbol);
temp = temp->next;
}
}
#ifdef __STDC__
char getendif ( void )
#else
char getendif()
#endif
{ /* Find matching endif when ignoring */
char word[80]; /* Buffer for symbols */
int ch;
int skip; /* Number of skipped #ifdefs */
skip = 1;
while (1) {
/* Scan through the file looking for starting lines */
if ((ch = fgetc(zin)) == EOF)
stop(); /* Get first char on the line */
if (ch != '#') { /* If not a # ignore line */
(void)putchar(ch);
Print;
continue;
}
ch = fgetarg(zin, word); /* Get the word after the # */
if (!strcmp(word, "ifdef") || !strcmp(word, "ifndef")) skip++;
/* Keep track of ifdefs & */
if (!strcmp(word, "endif")) skip--; /* endifs */
(void)printf("#%s%c", word, ch); /* Print the line out */
Print;
if (!skip) return('\n'); /* If matching endif, return */
}
}
#ifdef __STDC__
void gettable ( void )
#else
void gettable() /* Get & print a table of defines etc. */
#endif
{
char word[80]; /* Buffer for symbols */
int ch;
while (1) {
/* Scan through the file looking for starting lines */
if ((ch = fgetc(zin)) == EOF)
stop(); /* Get first char on the line */
if (ch != '#') { /* If not a # ignore line */
Goto;
continue;
}
ch = fgetarg(zin, word); /* Get the word after the # */
if (!strcmp(word, "define")) { /* Define: Define the */
ch = fgetarg(zin, word); /* symbol, and goto */
Define(word, MUTABLE); /* the end of line */
Goto;
continue;
}
if (!strcmp(word, "undef")) { /* Undef: Undefine the */
ch = fgetarg(zin, word); /* symbol, and goto */
Undefine(word, MUTABLE); /* the end of line */
Goto;
continue;
} /* Ifdef: */
if (!strcmp(word, "ifdef") || !strcmp(word, "ifndef")) {
ch = fgetarg(zin, word); /* Get the symbol */
if (find(word) != DEF)
Undefine(word, MUTABLE); /* undefine it */
Goto;
continue;
}
Goto; /* else ignore the line */
}
}
#ifdef __STDC__
void parse ( void )
#else
void parse()
#endif
{ /* Parse & remove ifdefs from C source */
char word[80]; /* Buffer for symbols */
int ch;
int proc; /* Should we be processing this bit? */
int skip; /* Number of skipped #ifdefs */
proc = 1;
skip = 0;
while (1) {
/* Scan through the file looking for starting lines */
if ((ch = fgetc(zin)) == EOF)
stop(); /* Get first char on the line */
if (ch != '#')
if (proc) { /* If not # and we're processing */
(void)putchar(ch); /* then print the line */
Print;
continue;
} else {
Goto; /* else just skip the line */
continue;
}
ch = fgetarg(zin, word); /* Get the word after the # */
if (!strcmp(word, "define") && proc) { /* Define: Define the */
ch = fgetarg(zin, word); /* symbol, and goto */
Define(word, MUTABLE); /* the end of line */
(void)printf("#define %s%c", word, ch);
Print;
continue;
}
if (!strcmp(word, "undef") && proc) { /* Undef: Undefine the */
ch = fgetarg(zin, word); /* symbol, and goto */
Undefine(word, MUTABLE); /* the end of line */
(void)printf("#undef %s%c", word, ch);
Print;
continue;
}
if (!strcmp(word, "if")) { /* If: we cannot handle these */
if (!proc) /* at the moment, so just */
skip++; /* treat them as an ignored */
else { /* definition */
(void)printf("#%s%c",word,ch);
Print;
ch = getendif(); /* Get matching endif */
continue;
}
}
if (!strcmp(word, "ifdef")) { /* Ifdef: */
if (!proc) /* If not processing */
skip++; /* skip it */
else {
ch = fgetarg(zin, word); /* Get the symbol */
switch (find(word)) {
case DEF:
break;
case IGN:
(void)printf("#ifdef %s%c", word, ch);
Print;
ch = getendif(); /* Get matching endif */
break;
/* If symbol undefined */
default:
Undefine(word, MUTABLE); /* undefine it */
proc = 0; /* & stop processing */
}
}
Goto;
continue;
}
if (!strcmp(word, "ifndef")) {
/* Ifndef: */
if (!proc) /* If not processing */
skip++; /* skip the line */
else {
ch = fgetarg(zin, word); /* Get the symbol */
switch (find(word)) { /* If defined, stop */
case DEF:
proc = 0; /* processing */
break;
case IGN:
(void)printf("#ifdef %s%c", word, ch);
Print;
ch = getendif(); /* Get matching endif */
break;
}
}
Goto;
continue;
}
if (!strcmp(word, "else") && !skip) { /* Else: Flip processing */
proc = !proc;
Goto;
continue;
}
if (!strcmp(word, "endif")) { /* Endif: If no skipped */
/* ifdefs turn processing */
if (!skip) /* on, else decrement the */
proc = 1; /* number of skips */
else
skip--;
Goto;
continue;
}
/* The word fails all of the above tests, so if we're */
/* processing, print the line. */
if (proc) {
(void)printf("#%s%c", word, ch);
Print;
} else
Goto;
}
}
#ifdef __STDC__
void usage ( void )
#else
void usage()
#endif
{
(void)fprintf(stderr, "Usage: ifdef [-t] [-Dsymbol] [-dsymbol] [-Usymbol] [-Isymbol] <file>\n");
exit(0);
}
#ifdef __STDC__
int main(int argc , char *argv [])
#else
int main(argc, argv)
int argc;
char *argv[];
#endif
{
char sym[80]; /* Temp symbol storage */
int c;
if (argc == 1) usage(); /* Catch the curious user */
while ((c = getopt(argc, argv, "tD:d:U:I:")) != EOF) {
switch (c) {
case 't':
table = 1; /* Get the various options */
break;
case 'd':
(void)strcpy(sym, optarg);
Define(sym, MUTABLE);
break;
case 'D':
(void)strcpy(sym, optarg);
Define(sym, IMMUTABLE);
break;
case 'U':
(void)strcpy(sym, optarg);
Undefine(sym, IMMUTABLE);
break;
case 'I':
(void)strcpy(sym, optarg);
Ignore(sym, IMMUTABLE);
break;
default: usage();
}
}
zin = stdin; /* If a C file is named */
/* Open stdin with it */
if (*argv[argc - 1] != '-') {
(void)fclose(zin);
if ((zin = fopen(argv[argc - 1], "r")) == NULL) {
perror("ifdef");
exit(1);
}
}
if (table)
gettable(); /* Either generate a table or */
else
parse(); /* parse & replace with the file */
return(0);
}