ref: 7ae0c4ae76b0c372e6c8bb622bd8527b74159a39
dir: /cc1/cpp.c/
#include <ctype.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../inc/sizes.h"
#include "../inc/cc.h"
#include "cc1.h"
/* TODO: preprocessor error must not rise recover */
static char *argp;
static unsigned arglen;
static unsigned numif;
static Symbol *lastmacro;
unsigned char ifstatus[NR_COND];
static bool
iden(char **str)
{
char c, *bp, *s = *str;
if (!isalpha(c = *s) && c != '_')
return 0;
for (bp = yytext; bp < &yytext[IDENTSIZ]; *bp++ = c) {
if ((c = *s) == '\0' || !isalnum(c) && c != '_')
break;
++s;
}
if (bp == &yytext[IDENTSIZ])
error("identifier too long in preprocessor");
*bp = '\0';
while (isspace(*s))
++s;
*str = s;
return 1;
}
static bool
string(char **input, char **str, char delim)
{
char c, *s = *input;
if (str)
*str = s;
while ((c = *s) && c != delim)
++s;
if (c == '\0')
return 0;
*s++ = '\0';
*input = s;
return 1;
}
static void
cleanup(char *s)
{
while (isspace(*s))
++s;
if (*s != '\0')
error("trailing characters after preprocessor directive");
}
static void
nextcpp(void)
{
next();
if (yytoken == EOFTOK) {
error("unterminated argument list invoking macro \"%s\"",
lastmacro->name);
}
if (yylen + 1 > arglen) {
error("argument overflow invoking macro \"%s\"",
lastmacro->name);
}
memcpy(argp, yytext, yylen);
argp += yylen;
*argp++ = ' ';
arglen -= yylen + 1;
}
static void
paren(void)
{
for (;;) {
nextcpp();
switch (yytoken) {
case ')':
return;
case '(':
paren();
break;
}
}
}
static void
parameter(void)
{
for (;;) {
nextcpp();
switch (yytoken) {
case ')':
case ',':
argp -= 2;
*argp++ = '\0';
return;
case '(':
paren();
break;
}
}
}
static bool
parsepars(char *buffer, char **listp, int nargs)
{
int n;
if (nargs == -1)
return 1;
if (ahead() != '(')
return 0;
next();
n = 0;
argp = buffer;
arglen = INPUTSIZ;
if (ahead() != ')') {
do {
*listp++ = argp;
parameter();
} while (++n < NR_MACROARG && yytoken == ',');
}
if (n == NR_MACROARG)
error("too much parameters in macro \"%s\"", lastmacro->name);
if (n != nargs) {
error("macro \"%s\" passed %d arguments, but it takes %d",
lastmacro->name, n, nargs);
}
return 1;
}
/*
* sym->u.s is a string with the following format:
* dd#string
* where dd is the number of arguments of the macro
* (-1 if it is a macro without arguments), and string
* is the macro definition, where @dd@ indicates the
* parameter number dd
*/
bool
expand(Symbol *sym)
{
unsigned len;
char *arglist[NR_MACROARG], buffer[INPUTSIZ];
char c, *bp, *arg, *s = sym->u.s;
lastmacro = sym;
if (!parsepars(buffer, arglist, atoi(s)))
return 0;
bp = addinput(NULL);
len = INPUTSIZ-1;
for (s += 3; c = *s; ++s) {
if (c != '@') {
if (len-- == 0)
goto expansion_too_long;
*bp++ = c;
} else {
unsigned size;
arg = arglist[atoi(++s)];
size = strlen(arg);
if (size > len)
goto expansion_too_long;
memcpy(bp, arg, size);
bp += size;
len -= size;
s += 2;
}
}
*bp = '\0';
return 1;
expansion_too_long:
error("expansion of macro \"%s\" is too long", lastmacro->name);
}
/*
* Parse an argument list (par0, par1, ...) and creates
* an array with pointers to all the arguments in the
* list
*/
static char *
parseargs(char *s, char *args[NR_MACROARG], int *nargs)
{
int n;
size_t len;
char *endp, c;
n = -1;
if (*s != '(')
goto set_nargs;
n = 0;
while (isspace(*s++))
/* nothing */;
if (*s == ')')
goto set_nargs;
for (n = 1; n <= NR_MACROARG; ++n) {
while (isspace(*s))
++s;
if (!isalpha(*s) && *s != '_')
error("macro arguments must be identifiers");
for (endp = s+1; isalnum(*endp) || *endp == '_'; ++endp)
/* nothing */;
if ((len = endp - s) > IDENTSIZ)
error("macro argument too long");
*args++ = s;
for (s = endp; isspace(*s); ++s)
*s = '\0';
c = *s;
*s++ = '\0';
if (c == ')')
break;
if (c == ',')
continue;
else
error("macro parameters must be comma-separated");
}
if (n > NR_MACROARG)
error("too much parameters in macro");
set_nargs:
*nargs = n;
return s;
}
/*
* Copy a string define, and substitute formal arguments of the
* macro into strings in the form @XX@, where XX is the position
* of the argument in the argument list.
*/
static char *
copydefine(char *s, char *args[], char *buff, int bufsiz, int nargs)
{
int n;
size_t ncopy;
char arroba[6], *p, **bp, c;
while ((c = *s) && bufsiz > 0) {
if (!isalpha(c) && c != '_' || nargs < 1) {
*buff++ = c;
++s, --bufsiz;
continue;
}
/* found an identifier, is it one of the macro arguments? */
for (p = s+1; isalnum(c = *p) || c == '_'; ++p)
/* nothing */;
ncopy = p - s;
bp = args;
for (n = 0; n < nargs; ++n) {
if (strncmp(s, *bp++, ncopy))
continue;
sprintf(arroba, "@%02d@", n);
s = arroba, ncopy = 4;
break;
}
if ((bufsiz -= ncopy) < 0)
goto too_long;
memcpy(buff, s, ncopy);
buff += ncopy, s = p;
}
if (bufsiz == 0)
goto too_long;
*buff = '\0';
return s;
too_long:
error("macro definition too long");
}
static char *
mkdefine(char *s, Symbol *sym)
{
int nargs;
char *args[NR_MACROARG], buff[LINESIZ+1];
s = parseargs(s, args, &nargs);
sprintf(buff, "%02d#", nargs);
while (isspace(*s))
++s;
if (*s != '\0')
s = copydefine(s, args, buff+3, LINESIZ-3, nargs);
sym->u.s = xstrdup(buff);
return s;
}
static void
define(char *s)
{
char *t;
Symbol *sym;
if (cppoff)
return;
if (!iden(&s))
error("#define must have an identifier as parameter");
sym = lookup(NS_CPP);
if ((sym->flags & ISDEFINED) && sym->ns == NS_CPP) {
warn("'%s' redefined", yytext);
free(sym->u.s);
}
sym->flags |= ISDEFINED;
sym->ns = NS_CPP;
for (t = s + strlen(s) + 1; isspace(*--t); *t = '\0')
/* nothing */;
mkdefine(s, sym);
return;
}
static void
include(char *s)
{
char delim, c, *p, *file;
if (cppoff)
return;
if ((c = *s++) == '>')
delim = '>';
else if (c == '"')
delim = '"';
else
goto bad_include;
if (!string(&s, &file, delim))
goto bad_include;
cleanup(s);
if (delim == '"' && addinput(file))
return;
abort();
not_found:
error("included file '%s' not found", s);
bad_include:
error("#include expects \"FILENAME\" or <FILENAME>");
}
static void
line(char *s)
{
char *file;
long n;
if (cppoff)
return;
if ((n = strtol(s, &s, 10)) <= 0 || n > USHRT_MAX)
error("first parameter of #line is not a positive integer");
switch (*s) {
case ' ':
case '\t':
while (isspace(*s))
++s;
if (*s == '\0')
goto end_string;
if (*s++ != '"' && !string(&s, &file, '"'))
goto bad_file;
setfname(file);
cleanup(s);
case '\0':
end_string:
setfline(n-1);
return;
default:
bad_file:
error("second parameter of #line is not a valid filename");
}
}
static void
pragma(char *s)
{
if (cppoff)
return;
return;
}
static void
usererr(char *s)
{
if (cppoff)
return;
error("#error %s", s);
}
static void
ifclause(char *s, int isdef)
{
Symbol *sym;
unsigned n = numif++;
if (numif == NR_COND-1)
error("too much nesting levels of conditional inclusion");
if (!iden(&s))
error("#ifdef clause must have an identifier as parameter");
cleanup(s);
sym = lookup(NS_CPP);
if (!(ifstatus[n] = (sym->flags & ISDEFINED) != 0 == isdef))
++cppoff;
return;
}
static void
ifdef(char *s)
{
ifclause(s, 1);
}
static void
ifndef(char *s)
{
ifclause(s, 0);
}
static void
endif(char *s)
{
if (numif == 0)
error("#endif without #if");
cleanup(s);
if (!ifstatus[--numif])
--cppoff;
return;
}
static void
elseclause(char *s)
{
struct ifstatus *ip;
if (numif == 0)
error("#else without #if");
cleanup(s);
cppoff += (ifstatus[numif-1] ^= 1) ? -1 : 1;
return;
}
bool
preprocessor(char *s)
{
static struct {
char *name;
void (*fun)(char *);
} *bp, cmds[] = {
"define", define,
"include", include,
"ifdef", ifdef,
"ifndef", ifndef,
"endif", endif,
"else", elseclause,
"line", line,
"pragma", pragma,
"error", usererr,
NULL, NULL
};
if (*s++ != '#')
return 0;
while (isspace(*s))
++s;
if (!iden(&s))
goto incorrect;
for (bp = cmds; bp->name; ++bp) {
if (strcmp(bp->name, yytext))
continue;
(*bp->fun)(s);
return 1;
}
incorrect:
error("invalid preprocessor directive #%s", yytext);
}