ack/lang/cem/cemcom.ansi/LLlex.c
ceriel 0bc88b77b2 fixed several problems:
- hex numbers and floating point numbers were wrong
- grammar was wrong; did not accept correct ANSI C
- prototype updates did not work
- float parameters to routines without prototype were not upgraded to double
- the dot operator no longer requires lvalue as left-hand-side
1989-02-07 13:16:02 +00:00

779 lines
17 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".
*/
/* $Header$ */
/* L E X I C A L A N A L Y Z E R */
#include "lint.h"
#include <alloc.h>
#include "nofloat.h"
#include "idfsize.h"
#include "numsize.h"
#include "debug.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"
/* Data about the token yielded */
struct token dot, ahead, aside;
#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 */
#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
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 < 2);
ASSERT(ASIDE == 0); /* ASIDE = 0; */
GetToken(&ahead);
LexStack[LexSP++] = dot;
}
PopLex()
{
ASSERT(LexSP > 0);
dot = LexStack[--LexSP];
}
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;
{
/* LexToken() 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;
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 == '#' || class(ch) == STSKIP)) {
/* blanks are allowed before hashes */
if (ch == '#') {
/* a control line follows */
domacro();
if (File_Inserted) {
File_Inserted = 0;
goto firstline;
}
}
}
/* 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 */
if (040 < ch && ch < 0177)
lexerror("garbage char %c", ch);
else
lexerror("garbage char \\%03o", ch);
goto again;
case STSIMP: /* a simple character, no part of compound token*/
if (ch == '/') { /* probably the start of comment */
ch = GetChar();
if (ch == '*') { /* start of comment */
skipcomment();
goto again;
}
else {
UnGetChar();
ch = '/'; /* restore ch */
}
}
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;
UnGetChar();
return ptok->tk_symb = ch;
case '&':
if (nch == '&')
return ptok->tk_symb = AND;
UnGetChar();
return ptok->tk_symb = ch;
case '+':
if (nch == '+')
return ptok->tk_symb = PLUSPLUS;
UnGetChar();
return ptok->tk_symb = ch;
case '-':
if (nch == '-')
return ptok->tk_symb = MINMIN;
if (nch == '>')
return ptok->tk_symb = ARROW;
UnGetChar();
return ptok->tk_symb = ch;
case '<':
if (AccFileSpecifier) {
UnGetChar(); /* pushback nch */
ptok->tk_bts = string_token("file specifier",
'>', &(ptok->tk_len));
return ptok->tk_symb = FILESPECIFIER;
}
if (nch == '<')
return ptok->tk_symb = LEFT;
if (nch == '=')
return ptok->tk_symb = LESSEQ;
UnGetChar();
return ptok->tk_symb = ch;
case '=':
if (nch == '=')
return ptok->tk_symb = EQUAL;
/* The following piece of code tries to recognise
old-fashioned assignment operators `=op'
Note however, that these are removed from the
ANSI C standard.
*/
switch (nch) {
case '+':
ptok->tk_symb = PLUSAB;
goto warn;
case '-':
ptok->tk_symb = MINAB;
goto warn;
case '*':
ptok->tk_symb = TIMESAB;
goto warn;
case '/':
ptok->tk_symb = DIVAB;
goto warn;
case '%':
ptok->tk_symb = MODAB;
goto warn;
case '>':
case '<':
GetChar(ch);
if (ch != nch) {
UnGetChar();
lexerror("illegal combination '=%c'",
nch);
}
ptok->tk_symb = nch == '<' ? LEFTAB : RIGHTAB;
goto warn;
case '&':
ptok->tk_symb = ANDAB;
goto warn;
case '^':
ptok->tk_symb = XORAB;
goto warn;
case '|':
ptok->tk_symb = ORAB;
warn:
warning("Old-fashioned assignment operator");
return ptok->tk_symb;
}
UnGetChar();
return ptok->tk_symb = ch;
case '>':
if (nch == '=')
return ptok->tk_symb = GREATEREQ;
if (nch == '>')
return ptok->tk_symb = RIGHT;
UnGetChar();
return ptok->tk_symb = ch;
case '|':
if (nch == '|')
return ptok->tk_symb = OR;
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();
case STIDF:
{
register char *tg = &buf[0];
register int pos = -1;
register int hash;
register struct idf *idef;
extern int idfsize; /* ??? */
hash = STARTHASH();
do { /* read the identifier */
if (++pos < idfsize) {
*tg++ = ch;
hash = ENHASH(hash, ch, pos);
}
ch = GetChar();
} while (in_idf(ch));
hash = STOPHASH(hash);
if (ch != EOI)
UnGetChar();
*tg++ = '\0'; /* mark the end of the identifier */
idef = ptok->tk_idf = idf_hashed(buf, tg - buf, hash);
idef->id_file = ptok->tk_file;
idef->id_line = ptok->tk_line;
#ifndef NOPP
if (idef->id_macro && ReplaceMacros) {
if (idef->id_macro->mc_count > 0)
idef->id_macro->mc_count--;
else 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 char *np = &buf[1];
register int base = 10;
register int vch;
register arith val = 0;
if (ch == '.') {
#ifndef NOFLOAT
/* A very embarrasing ambiguity. We have either a
floating point number or field operator or
ELLIPSIS.
*/
vch = GetChar();
if (!is_dig(vch)) { /* . or ... */
if (vch == '.') {
if ((vch = GetChar()) == '.')
return ptok->tk_symb = ELLIPSIS;
/* This is funny: we can't push the
second dot back. But then again
..<ch> is already an error in C,
so why bother ?
*/
UnGetChar();
lexerror("illegal combination '..'");
}
UnGetChar();
return ptok->tk_symb = '.';
}
*np++ = '0';
UnGetChar();
#else
if ((vch = GetChar()) == '.') {
if ((vch = GetChar()) == '.')
return ptok->tk_symb = ELLIPSIS;
UnGetChar();
lexerror("illegal combination '..'");
}
UnGetChar();
return ptok->tk_symb = '.';
#endif
}
if (ch == '0') {
*np++ = ch;
ch = GetChar();
if (ch == 'x' || ch == 'X') {
base = 16;
ch = GetChar();
}
else
base = 8;
}
while (vch = val_in_base(ch, base), vch >= 0) {
val = val*base + vch;
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
}
if (is_suf(ch)) {
register int suf_long = 0;
register int suf_unsigned = 0;
/* The type of the integal constant is
based on its suffix.
*/
do {
switch (ch) {
case 'l':
case 'L':
suf_long++;
break;
case 'u':
case 'U':
suf_unsigned++;
break;
}
ch = GetChar();
} while (is_suf(ch));
UnGetChar();
if (suf_long > 1)
lexerror("only one long suffix allowed");
if (suf_unsigned > 1)
lexerror("only one unsigned suffix allowed");
ptok->tk_fund = (suf_long && suf_unsigned) ? ULONG :
(suf_long) ? LONG : UNSIGNED;
ptok->tk_ival = val;
return ptok->tk_symb = INTEGER;
}
#ifndef NOFLOAT
if (base == 16 || !(ch == '.' || ch == 'e' || ch == 'E'))
#endif NOFLOAT
{
UnGetChar();
ptok->tk_ival = val;
/* The semantic analyser must know if the
integral constant is given in octal/hexa-
decimal form, in which case its type is
UNSIGNED, or in decimal form, in which case
its type is signed, indicated by
the fund INTEGER.
*/
ptok->tk_fund =
(base == 10 || (base == 8 && val == (arith)0))
? INTEGER : UNSIGNED;
return ptok->tk_symb = INTEGER;
}
/* where's the test for the length of the integral ??? */
#ifndef NOFLOAT
if (ch == '.'){
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
}
while (is_dig(ch)){
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
}
if (ch == 'e' || ch == 'E') {
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
if (ch == '+' || ch == '-') {
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
}
if (!is_dig(ch)) {
lexerror("malformed floating constant");
if (np < &buf[NUMSIZE])
*np++ = ch;
}
while (is_dig(ch)) {
if (np < &buf[NUMSIZE])
*np++ = ch;
ch = GetChar();
}
}
/* The type of an integral floating point
constant may be given by the float (f)
or long double (l) suffix.
*/
if (ch == 'f' || ch == 'F')
ptok->tk_fund = FLOAT;
else if (ch == 'l' || ch == 'L')
ptok->tk_fund = LNGDBL;
else {
ptok->tk_fund = DOUBLE;
UnGetChar();
}
*np++ = '\0';
buf[0] = '-'; /* good heavens... */
if (np == &buf[NUMSIZE+1]) {
lexerror("floating constant too long");
ptok->tk_fval = Salloc("0.0",(unsigned) 5) + 1;
}
else
ptok->tk_fval = Salloc(buf,(unsigned) (np - buf)) + 1;
return ptok->tk_symb = FLOATING;
#endif NOFLOAT
}
case STEOI: /* end of text on source file */
return ptok->tk_symb = EOI;
default: /* this cannot happen */
crash("bad class for char 0%o", ch);
}
/*NOTREACHED*/
}
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;
NoUnstack++;
c = GetChar();
#ifdef LINT
lint_start_comment();
lint_comment_char(c);
#endif LINT
do {
while (c != '*') {
if (class(c) == STNL) {
++LineNumber;
} else
if (c == EOI) {
NoUnstack--;
#ifdef LINT
lint_end_comment();
#endif LINT
return;
}
if (c == '/' && (c = GetChar()) == '*')
strict("extra comment delimiter found");
c = GetChar();
#ifdef LINT
lint_comment_char(c);
#endif LINT
} /* last Character seen was '*' */
c = GetChar();
#ifdef LINT
lint_comment_char(c);
#endif LINT
} while (c != '/');
#ifdef LINT
lint_end_comment();
#endif LINT
NoUnstack--;
}
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;
val = val*256 + ch;
size++;
ch = GetChar();
}
if (size > 1)
strict("%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 == '\\')
ch = quoted(GetChar());
str[pos++] = ch;
if (pos == str_size)
str = Srealloc(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 = val_in_base(ch, 16), vch == -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
val_in_base(ch, base)
register int ch;
{
switch (base) {
case 8:
return (is_dig(ch) && ch < '9') ? ch - '0' : -1;
case 10:
return is_dig(ch) ? ch - '0' : -1;
case 16:
return is_dig(ch) ? ch - '0'
: is_hex(ch) ? (ch - 'a' + 10) & 017
: -1;
default:
fatal("(val_in_base) illegal base value %d", base);
/* NOTREACHED */
}
}
int
GetChar()
{
/* The routines GetChar and trigraph parses the trigraph
sequences and removes occurences of \\\n.
*/
register int ch;
again:
LoadChar(ch);
/* possible trigraph sequence */
if (ch == '?')
ch = trigraph();
/* \\\n are removed from the input stream */
if (ch == '\\') {
LoadChar(ch);
if (ch == '\n') {
++LineNumber;
goto again;
}
PushBack();
ch = '\\';
}
return(LexSave = ch);
}
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('?');
}