ack/lang/cem/cemcom.ansi/LLlex.c
1994-06-27 08:03:14 +00:00

850 lines
18 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Id$ */
/* L E X I C A L A N A L Y Z E R */
#include "debug.h"
#include "lint.h"
#include <alloc.h>
#include "idfsize.h"
#include "numsize.h"
#include "strsize.h"
#include "nopp.h"
#include "input.h"
#include "arith.h"
#include "def.h"
#include "macro.h"
#include "idf.h"
#include "LLlex.h"
#include "Lpars.h"
#include "class.h"
#include "assert.h"
#include "sizes.h"
#include "specials.h" /* registration of special identifiers */
/* Data about the token yielded */
struct token dot, ahead, aside;
int token_nmb = 0; /* number of the ahead token */
int tk_nmb_at_last_syn_err = -5/*ERR_SHADOW*/;
/* token number at last syntax error */
int idfsize = IDFSIZE;
char sp_occurred[SP_TOTAL+1];
#ifndef NOPP
int ReplaceMacros = 1; /* replacing macros */
int AccDefined = 0; /* accept "defined(...)" */
int UnknownIdIsZero = 0; /* interpret unknown id as integer 0 */
int Unstacked = 0; /* an unstack is done */
extern int InputLevel;
#endif
int AccFileSpecifier = 0; /* return filespecifier <...> */
int EoiForNewline = 0; /* return EOI upon encountering newline */
int File_Inserted = 0; /* a file has just been inserted */
int LexSave = 0; /* last character read by GetChar */
#define MAX_LL_DEPTH 2
#define FLG_ESEEN 0x01 /* possibly a floating point number */
#define FLG_DOTSEEN 0x02 /* certainly a floating point number */
extern arith full_mask[];
#ifdef LINT
extern int lint_skip_comment;
#endif
#ifndef NOPP
static struct token LexStack[MAX_LL_DEPTH];
static LexSP = 0;
/* In PushLex() the actions are taken in order to initialise or
re-initialise the lexical scanner.
E.g. at the invocation of a sub-parser that uses LLlex(), the
state of the current parser should be saved.
*/
PushLex()
{
ASSERT(LexSP < MAX_LL_DEPTH);
ASSERT(ASIDE == 0); /* ASIDE = 0; */
GetToken(&ahead);
LexStack[LexSP++] = dot;
}
PopLex()
{
ASSERT(LexSP > 0);
dot = LexStack[--LexSP];
}
#endif /* NOPP */
int
LLlex()
{
/* LLlex() plays the role of Lexical Analyzer for the C parser.
The look-ahead and putting aside of tokens are taken into
account.
*/
if (ASIDE) { /* a token is put aside */
dot = aside;
ASIDE = 0;
}
else { /* read ahead and return the old one */
#ifdef LINT
lint_comment_ahead();
#endif /* LINT */
dot = ahead;
/* the following test is performed due to the dual
task of LLlex(): it is also called for parsing the
restricted constant expression following a #if or
#elif. The newline character causes EOF to be
returned in this case to stop the LLgen parsing task.
*/
if (DOT != EOI)
GetToken(&ahead);
else
DOT = EOF;
}
return DOT;
}
char *string_token();
arith char_constant();
int
GetToken(ptok)
register struct token *ptok;
{
/* GetToken() is the actual token recognizer. It calls the
control line interpreter if it encounters a "\n{w}*#"
combination. Macro replacement is also performed if it is
needed.
*/
char buf[(IDFSIZE > NUMSIZE ? IDFSIZE : NUMSIZE) + 1];
register int ch, nch;
token_nmb++;
if (File_Inserted) {
File_Inserted = 0;
goto firstline;
}
again: /* rescan the input after an error or replacement */
ch = GetChar();
go_on: /* rescan, the following character has been read */
if ((ch & 0200) && ch != EOI) /* stop on non-ascii character */
{
fatal("non-ascii '\\%03o' read", ch & 0377);
}
/* keep track of the place of the token in the file */
ptok->tk_file = FileName;
ptok->tk_line = LineNumber;
switch (class(ch)) { /* detect character class */
case STNL: /* newline, vertical space or formfeed */
firstline:
LineNumber++; /* also at vs and ff */
ptok->tk_file = FileName;
ptok->tk_line = LineNumber;
if (EoiForNewline) /* called in control line */
/* a newline in a control line indicates the
end-of-information of the line.
*/
return ptok->tk_symb = EOI;
while ((ch = GetChar()),
(ch == '#'
#ifndef NOPP
|| ch == '/'
#endif
|| class(ch) == STSKIP)) {
/* blanks are allowed before hashes */
if (ch == '#') {
/* a control line follows */
domacro();
#ifndef NOPP
if (File_Inserted) {
File_Inserted = 0;
goto firstline;
}
} else if (ch == '/') {
if ((GetChar() == '*') && !InputLevel) {
skipcomment();
} else {
UnGetChar();
break;
}
#endif /* NOPP */
}
}
/* We have to loop here, because in
`domacro' the nl, vt or ff is read. The
character following it may again be a `#'.
*/
goto go_on;
case STSKIP: /* just skip the skip characters */
goto again;
case STGARB: /* garbage character */
#ifndef NOPP
garbage:
#endif
if (040 < ch && ch < 0177) {
return ptok->tk_symb = ch;
} else {
lexerror("garbage char \\%03o", ch);
}
goto again;
case STSIMP: /* a simple character, no part of compound token*/
return ptok->tk_symb = ch;
case STCOMP: /* maybe the start of a compound token */
nch = GetChar(); /* character lookahead */
switch (ch) {
case '!':
if (nch == '=')
return ptok->tk_symb = NOTEQUAL;
break;
case '&':
if (nch == '&')
return ptok->tk_symb = AND;
if (nch == '=')
return ptok->tk_symb = ANDAB;
break;
case '+':
if (nch == '+')
return ptok->tk_symb = PLUSPLUS;
if (nch == '=')
return ptok->tk_symb = PLUSAB;
break;
case '-':
if (nch == '-')
return ptok->tk_symb = MINMIN;
if (nch == '>')
return ptok->tk_symb = ARROW;
if (nch == '=')
return ptok->tk_symb = MINAB;
break;
case '<':
if (AccFileSpecifier) {
UnGetChar(); /* pushback nch */
ptok->tk_bts = string_token("file specifier",
'>', &(ptok->tk_len));
return ptok->tk_symb = FILESPECIFIER;
}
if (nch == '<') {
if ((nch = GetChar()) == '=')
return ptok->tk_symb = LEFTAB;
UnGetChar();
return ptok->tk_symb = LEFT;
}
if (nch == '=')
return ptok->tk_symb = LESSEQ;
break;
case '=':
if (nch == '=')
return ptok->tk_symb = EQUAL;
break;
case '>':
if (nch == '=')
return ptok->tk_symb = GREATEREQ;
if (nch == '>') {
if ((nch = GetChar()) == '=')
return ptok->tk_symb = RIGHTAB;
UnGetChar();
return ptok->tk_symb = RIGHT;
}
break;
case '|':
if (nch == '|')
return ptok->tk_symb = OR;
if (nch == '=')
return ptok->tk_symb = ORAB;
break;
case '%':
if (nch == '=')
return ptok->tk_symb = MODAB;
break;
case '*':
if (nch == '=')
return ptok->tk_symb = TIMESAB;
break;
case '^':
if (nch == '=')
return ptok->tk_symb = XORAB;
break;
case '/':
#ifndef NOPP
if (nch == '*' && !InputLevel) {
skipcomment();
goto again;
}
#endif
if (nch == '=')
return ptok->tk_symb = DIVAB;
break;
default:
crash("bad class for char 0%o", ch);
/* NOTREACHED */
}
UnGetChar();
return ptok->tk_symb = ch;
case STCHAR: /* character constant */
ptok->tk_ival = char_constant("character");
ptok->tk_fund = INT;
return ptok->tk_symb = INTEGER;
case STSTR: /* string */
ptok->tk_bts = string_token("string", '"', &(ptok->tk_len));
ptok->tk_fund = CHAR; /* string of characters */
return ptok->tk_symb = STRING;
case STELL: /* wide character constant/string prefix */
nch = GetChar();
if (nch == '"') {
ptok->tk_bts = string_token("wide character string",
'"', &(ptok->tk_len));
ptok->tk_fund = WCHAR; /* string of wide characters */
return ptok->tk_symb = STRING;
} else if (nch == '\'') {
ptok->tk_ival = char_constant("wide character");
ptok->tk_fund = INT;
return ptok->tk_symb = INTEGER;
}
UnGetChar();
/* fallthrough */
case STIDF:
{
register char *tg = &buf[0];
register int pos = -1;
register struct idf *idef;
extern int idfsize; /* ??? */
#ifndef NOPP
int NoExpandNext = 0;
if (Unstacked) EnableMacros(); /* unstack macro's when allowed. */
if (ch == NOEXPM) {
NoExpandNext = 1;
ch = GetChar();
}
#endif
do { /* read the identifier */
if (++pos < idfsize) {
*tg++ = ch;
}
ch = GetChar();
} while (in_idf(ch));
if (ch != EOI)
UnGetChar();
*tg++ = '\0'; /* mark the end of the identifier */
idef = ptok->tk_idf = str2idf(buf, 1);
sp_occurred[idef->id_special] = 1;
idef->id_file = ptok->tk_file;
idef->id_line = ptok->tk_line;
#ifndef NOPP
if (idef->id_macro && ReplaceMacros && !NoExpandNext) {
if (replace(idef))
goto again;
}
if (UnknownIdIsZero && idef->id_reserved != SIZEOF) {
ptok->tk_ival = (arith)0;
ptok->tk_fund = INT;
return ptok->tk_symb = INTEGER;
}
#endif /* NOPP */
ptok->tk_symb = (
idef->id_reserved
? idef->id_reserved
: idef->id_def && idef->id_def->df_sc == TYPEDEF
? TYPE_IDENTIFIER
: IDENTIFIER
);
return IDENTIFIER;
}
case STNUM: /* a numeric constant */
{
register int siz_left = NUMSIZE - 1;
register char *np = &buf[0];
int flags = 0;
#define store(ch) if (--siz_left >= 0) \
*np++ = ch;
if (ch == '.') {
/* An embarrasing ambiguity. We have either a
pp-number, a field operator, an ELLIPSIS or
an error (..).
*/
ch = GetChar();
if (!is_dig(ch)) { /* . or ... */
if (ch == '.') {
if ((ch = GetChar()) == '.')
return ptok->tk_symb = ELLIPSIS;
UnGetChar(); /* not '.' */
ChPushBack('.'); /* sigh ... */
} else
UnGetChar(); /* not '.' */
return ptok->tk_symb = '.';
}
UnGetChar();
ch = '.';
flags |= FLG_DOTSEEN;
}
store(ch);
ch = GetChar();
while(in_idf(ch) || ch == '.') {
store(ch);
if (ch == '.') flags |= FLG_DOTSEEN;
if (ch == 'e' || ch == 'E') {
flags |= FLG_ESEEN;
ch = GetChar();
if (ch == '+' || ch == '-') {
flags |= FLG_DOTSEEN; /* trick */
store(ch);
ch = GetChar();
}
} else ch = GetChar();
}
store('\0');
UnGetChar();
np = &buf[0];
ch = *np++;
if (siz_left < 0) {
lexerror("number too long");
if ((flags & FLG_DOTSEEN)
|| (flags & FLG_ESEEN
&& !(ch == '0'
&& (*np == 'x' || *np == 'X')))) {
ptok->tk_fval = Salloc("0.0", (unsigned) 4);
ptok->tk_fund = DOUBLE;
return ptok->tk_symb = FLOATING;
}
ptok->tk_ival = 1;
ptok->tk_fund = ULONG;
ptok->tk_symb = INTEGER;
}
/* Now, the pp-number must be converted into a token */
if ((flags & FLG_DOTSEEN)
|| (flags & FLG_ESEEN
&& !(ch == '0' && (*np == 'x' || *np == 'X')))) {
strflt2tok(&buf[0], ptok);
return ptok->tk_symb = FLOATING;
}
strint2tok(&buf[0], ptok);
return ptok->tk_symb = INTEGER;
}
case STEOI: /* end of text on source file */
return ptok->tk_symb = EOI;
#ifndef NOPP
case STMSPEC:
if (!InputLevel) goto garbage;
if (ch == TOKSEP) goto again;
/* fallthrough shouldn't happen */
#endif
default: /* this cannot happen */
crash("bad class for char 0%o", ch);
}
/*NOTREACHED*/
}
#ifndef NOPP
skipcomment()
{
/* The last character read has been the '*' of '/_*'. The
characters, except NL and EOI, between '/_*' and the first
occurring '*_/' are not interpreted.
NL only affects the LineNumber. EOI is not legal.
Important note: it is not possible to stop skipping comment
beyond the end-of-file of an included file.
EOI is returned by LoadChar only on encountering EOF of the
top-level file...
*/
register int c, oldc = '\0';
NoUnstack++;
c = GetChar();
#ifdef LINT
if (! lint_skip_comment) {
lint_start_comment();
lint_comment_char(c);
}
#endif /* LINT */
do {
while (c != '*') {
if (class(c) == STNL) {
++LineNumber;
} else if (c == EOI) {
NoUnstack--;
#ifdef LINT
if (! lint_skip_comment) lint_end_comment();
#endif /* LINT */
return;
}
oldc = c;
c = GetChar();
#ifdef LINT
if (! lint_skip_comment) lint_comment_char(c);
#endif /* LINT */
} /* last Character seen was '*' */
c = GetChar();
if ( c != '/' && oldc == '/')
lexwarning("comment inside comment ?");
oldc = '*';
#ifdef LINT
if (! lint_skip_comment) lint_comment_char(c);
#endif /* LINT */
} while (c != '/');
#ifdef LINT
if (! lint_skip_comment) lint_end_comment();
#endif /* LINT */
NoUnstack--;
}
#endif /* NOPP */
arith
char_constant(nm)
char *nm;
{
register arith val = 0;
register int ch;
int size = 0;
ch = GetChar();
if (ch == '\'')
lexerror("%s constant too short", nm);
else
while (ch != '\'') {
if (ch == '\n') {
lexerror("newline in %s constant", nm);
LineNumber++;
break;
}
if (ch == '\\')
ch = quoted(GetChar());
if (ch >= 128) ch -= 256;
if (size < (int)int_size)
val |= ch << 8 * size;
size++;
ch = GetChar();
}
if (size > 1)
lexstrict("%s constant includes more than one character", nm);
if (size > (int)int_size)
lexerror("%s constant too long", nm);
return val;
}
char *
string_token(nm, stop_char, plen)
char *nm;
int *plen;
{
register int ch;
register int str_size;
register char *str = Malloc((unsigned) (str_size = ISTRSIZE));
register int pos = 0;
ch = GetChar();
while (ch != stop_char) {
if (ch == '\n') {
lexerror("newline in %s", nm);
LineNumber++;
break;
}
if (ch == EOI) {
lexerror("end-of-file inside %s", nm);
break;
}
if (ch == '\\' && !AccFileSpecifier)
ch = quoted(GetChar());
str[pos++] = ch;
if (pos == str_size)
str = Realloc(str, (unsigned) (str_size += RSTRSIZE));
ch = GetChar();
}
str[pos++] = '\0'; /* for filenames etc. */
*plen = pos;
return str;
}
int
quoted(ch)
register int ch;
{
/* quoted() replaces an escaped character sequence by the
character meant.
*/
/* first char after backslash already in ch */
if (!is_oct(ch)) { /* a quoted char */
switch (ch) {
case 'n':
ch = '\n';
break;
case 't':
ch = '\t';
break;
case 'b':
ch = '\b';
break;
case 'r':
ch = '\r';
break;
case 'f':
ch = '\f';
break;
case 'a': /* alert */
ch = '\007';
break;
case 'v': /* vertical tab */
ch = '\013';
break;
case 'x': /* quoted hex */
{
register int hex = 0;
register int vch;
for (;;) {
ch = GetChar();
if ((vch = hex_val(ch)) == -1)
break;
hex = hex * 16 + vch;
}
UnGetChar();
ch = hex;
}
}
}
else { /* a quoted octal */
register int oct = 0, cnt = 0;
do {
oct = oct*8 + (ch-'0');
ch = GetChar();
} while (is_oct(ch) && ++cnt < 3);
UnGetChar();
ch = oct;
}
return ch&0377;
}
int
hex_val(ch)
register int ch;
{
return is_dig(ch) ? ch - '0'
: is_hex(ch) ? (ch - 'a' + 10) & 017
: -1;
}
int
GetChar()
{
/* The routines GetChar and trigraph parses the trigraph
sequences and removes occurences of \\\n.
*/
register int ch;
#ifndef NOPP
again:
#endif
LoadChar(ch);
#ifndef NOPP
/* possible trigraph sequence */
if (ch == '?')
ch = trigraph();
/* \<newline> is removed from the input stream */
if (ch == '\\') {
LoadChar(ch);
if (ch == '\n') {
++LineNumber;
goto again;
}
PushBack();
ch = '\\';
}
#endif
return(LexSave = ch);
}
#ifndef NOPP
int
trigraph()
{
register int ch;
LoadChar(ch);
if (ch == '?') {
LoadChar(ch);
switch (ch) { /* its a trigraph */
case '=':
ch = '#';
return(ch);
case '(':
ch = '[';
return(ch);
case '/':
ch = '\\';
return(ch);
case ')':
ch = ']';
return(ch);
case '\'':
ch = '^';
return(ch);
case '<':
ch = '{';
return(ch);
case '!':
ch = '|';
return(ch);
case '>':
ch = '}';
return(ch);
case '-':
ch = '~';
return(ch);
}
PushBack();
}
PushBack();
return('?');
}
#endif
/* strflt2tok only checks the syntax of the floating-point number and
* selects the right type for the number.
*/
strflt2tok(fltbuf, ptok)
char fltbuf[];
struct token *ptok;
{
register char *cp = fltbuf;
int malformed = 0;
while (is_dig(*cp)) cp++;
if (*cp == '.') {
cp++;
while (is_dig(*cp)) cp++;
}
if (*cp == 'e' || *cp == 'E') {
cp++;
if (*cp == '+' || *cp == '-')
cp++;
if (!is_dig(*cp)) malformed++;
while (is_dig(*cp)) cp++;
}
if (*cp == 'f' || *cp == 'F') {
if (*(cp + 1)) malformed++;
*cp = '\0';
ptok->tk_fund = FLOAT;
} else if (*cp == 'l' || *cp == 'L') {
if (*(cp + 1)) malformed++;
*cp = '\0';
ptok->tk_fund = LNGDBL;
} else {
if (*cp) malformed++;
ptok->tk_fund = DOUBLE;
}
if (malformed) {
lexerror("malformed floating constant");
ptok->tk_fval = Salloc("0.0", (unsigned) 4);
} else {
ptok->tk_fval = Salloc(fltbuf, (unsigned) (cp - fltbuf + 1));
}
}
strint2tok(intbuf, ptok)
char intbuf[];
struct token *ptok;
{
register char *cp = intbuf;
int base = 10;
arith val = 0, dig, ubound;
int uns_flg = 0, lng_flg = 0, malformed = 0, ovfl = 0;
int fund;
ASSERT(*cp != '-');
if (*cp == '0') {
cp++;
if (*cp == 'x' || *cp == 'X') {
cp++;
base = 16;
} else base = 8;
}
/* The upperbound will be the same as when computed with
* max_unsigned_arith / base (since base is even). The problem here
* is that unsigned arith is not accepted by all compilers.
*/
ubound = max_arith / (base / 2);
while (is_hex(*cp)) {
dig = hex_val(*cp);
if (dig >= base) {
malformed++; /* ignore */
}
else {
if (val < 0 || val > ubound) ovfl++;
val *= base;
if (val < 0 && val + dig >= 0) ovfl++;
val += dig;
}
cp++;
}
while (*cp) {
if (*cp == 'l' || *cp == 'L') lng_flg++;
else if (*cp == 'u' || *cp == 'U') uns_flg++;
else break;
cp++;
}
if (*cp) {
malformed++;
}
if (malformed) {
lexerror("malformed %s integer constant",
(base == 10 ? "decimal"
: (base == 8 ? "octal"
: "hexadecimal")));
} else {
if (lng_flg > 1)
lexerror("only one long suffix allowed");
if (uns_flg > 1)
lexerror("only one unsigned suffix allowed");
}
if (ovfl) {
lexwarning("overflow in constant");
fund = ULONG;
} else if (!lng_flg && (val & full_mask[(int)int_size]) == val) {
if (val >= 0 && val <= max_int) {
fund = INT;
} else if (int_size == long_size) {
fund = UNSIGNED;
} else if (base == 10 && !uns_flg)
fund = LONG;
else fund = UNSIGNED;
} else if((val & full_mask[(int)long_size]) == val) {
if (val >= 0) fund = LONG;
else fund = ULONG;
} else { /* sizeof(arith) is greater than long_size */
ASSERT(arith_size > long_size);
lexwarning("constant too large for target machine");
/* cut the size to prevent further complaints */
val &= full_mask[(int)long_size];
fund = ULONG;
}
if (lng_flg) {
/* fund can't be INT */
if (fund == UNSIGNED) fund = ULONG;
}
if (uns_flg) {
if (fund == INT) fund = UNSIGNED;
else if (fund == LONG) fund = ULONG;
}
ptok->tk_fund = fund;
ptok->tk_ival = val;
}