ref: c79199da3e3565e28c2220a8474712a9fabc76e4
dir: /src/cmd/cc/cc2/parser.c/
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <scc/cstd.h>
#include <scc/scc.h>
#include "cc2.h"
#define STACKSIZ 50
extern Type int8type, int16type, int32type, int64type,
uint8type, uint16type, uint32type, uint64type,
float32type, float64type, float80type,
booltype,
ptrtype,
voidtype,
arg_type;
Type funetype = {
.flags = FUNF | ELLIPS
};
Type funtype = {
.flags = FUNF
};
union tokenop {
void *arg;
unsigned op;
};
struct swtch {
int nr;
Node *first;
Node *last;
};
static struct swtch swtbl[NR_BLOCK], *swp = swtbl;
static Symbol *lastfun;
typedef void parsefun(char *, union tokenop);
static parsefun type, symbol, getname, unary, binary, ternary, call,
constant, composed, binit, einit,
jump, oreturn, loop, assign,
ocase, bswitch, eswitch, builtin;
typedef void evalfun(void);
static evalfun vardecl, beginfun, endfun, endpars, stmt,
array, aggregate, flddecl, labeldcl;
static struct decoc {
void (*eval)(void);
void (*parse)(char *token, union tokenop);
union tokenop u;
} optbl[] = { /* eval parse args */
['A'] = { vardecl, symbol, .u.op = SAUTO<<8 | OAUTO},
['R'] = { vardecl, symbol, .u.op = SREG<<8 | OREG},
['G'] = { vardecl, symbol, .u.op = SGLOB<<8 | OMEM},
['X'] = { vardecl, symbol, .u.op = SEXTRN<<8 | OMEM},
['Y'] = { vardecl, symbol, .u.op = SPRIV<<8 | OMEM},
['T'] = { vardecl, symbol, .u.op = SLOCAL<<8 | OMEM},
['M'] = { flddecl, symbol, .u.op = SMEMB<<8 | OMEM},
['L'] = { labeldcl, symbol, .u.op = SLABEL<<8 | OLABEL},
['C'] = { NULL, type, .u.arg = &int8type},
['I'] = { NULL, type, .u.arg = &int16type},
['W'] = { NULL, type, .u.arg = &int32type},
['Q'] = { NULL, type, .u.arg = &int64type},
['K'] = { NULL, type, .u.arg = &uint8type},
['N'] = { NULL, type, .u.arg = &uint16type},
['Z'] = { NULL, type, .u.arg = &uint32type},
['O'] = { NULL, type, .u.arg = &uint64type},
['J'] = { NULL, type, .u.arg = &float32type},
['D'] = { NULL, type, .u.arg = &float64type},
['H'] = { NULL, type, .u.arg = &float80type},
['0'] = { NULL, type, .u.arg = &voidtype},
['B'] = { NULL, type, .u.arg = &booltype},
['P'] = { NULL, type, .u.arg = &ptrtype},
['E'] = { NULL, type, .u.arg = &funetype},
['1'] = { NULL, type, .u.arg = &arg_type},
['F'] = { NULL, type, .u.arg = &funtype},
['V'] = { array,composed, 0},
['U'] = {aggregate,composed, 0},
['S'] = {aggregate,composed, 0},
['"'] = { NULL, getname, 0},
['{'] = { beginfun, NULL, 0},
['}'] = { endfun, NULL, 0},
['('] = { NULL, binit, 0},
[')'] = { NULL, einit, 0},
['\\'] = { endpars, NULL, 0},
['\t'] = { stmt, NULL, 0},
['~'] = { NULL, unary, .u.op = OCPL},
['_'] = { NULL, unary, .u.op = OSNEG},
['\''] = { NULL, unary, .u.op = OADDR},
['@'] = { NULL, unary, .u.op = OPTR},
['g'] = { NULL, unary, .u.op = OCAST},
['p'] = { NULL, unary, .u.op = OPAR},
['n'] = { NULL, unary, .u.op = ONEG},
['a'] = { NULL, binary, .u.op = OAND},
['o'] = { NULL, binary, .u.op = OOR},
['.'] = { NULL, binary, .u.op = OFIELD},
['+'] = { NULL, binary, .u.op = OADD},
['-'] = { NULL, binary, .u.op = OSUB},
['*'] = { NULL, binary, .u.op = OMUL},
['%'] = { NULL, binary, .u.op = OMOD},
['/'] = { NULL, binary, .u.op = ODIV},
['l'] = { NULL, binary, .u.op = OSHL},
['r'] = { NULL, binary, .u.op = OSHR},
['<'] = { NULL, binary, .u.op = OLT},
['>'] = { NULL, binary, .u.op = OGT},
['['] = { NULL, binary, .u.op = OLE},
[']'] = { NULL, binary, .u.op = OGE},
['='] = { NULL, binary, .u.op = OEQ},
['!'] = { NULL, binary, .u.op = ONE},
['&'] = { NULL, binary, .u.op = OBAND},
['|'] = { NULL, binary, .u.op = OBOR},
['^'] = { NULL, binary, .u.op = OBXOR},
[','] = { NULL, binary, .u.op = OCOMMA},
['m'] = { NULL, builtin,.u.op = OBUILTIN},
[':'] = { NULL, assign, .u.op = OASSIG},
['?'] = { NULL, ternary, .u.op = OASK},
['c'] = { NULL, call, .u.op = OCALL},
['z'] = { NULL, call, .u.op = OCALLE},
['#'] = { NULL,constant, .u.op = OCONST},
['j'] = { NULL, jump, .u.op = OJMP},
['y'] = { NULL, jump, .u.op = OBRANCH},
['h'] = { NULL, oreturn, .u.op = ORET},
['i'] = { NULL, NULL, .u.op = OINC},
['d'] = { NULL, NULL, .u.op = ODEC},
['b'] = { NULL, loop, .u.op = OBLOOP},
['e'] = { NULL, loop, .u.op = OELOOP},
['v'] = { NULL, ocase, .u.op = OCASE},
['f'] = { NULL, ocase, .u.op = ODEFAULT},
['t'] = { NULL, eswitch, .u.op = OESWITCH},
['s'] = { NULL, bswitch, .u.op = OBSWITCH},
};
static int sclass, inpars, ininit, endf, lineno;
static void *stack[STACKSIZ], **sp = stack;
static Node *
push(void *elem)
{
if (sp == &stack[STACKSIZ])
error(ESTACKO);
return *sp++ = elem;
}
static void *
pop(void)
{
if (sp == stack)
error(ESTACKU);
return *--sp;
}
static int
empty(void)
{
return sp == stack;
}
static void
type(char *token, union tokenop u)
{
push(u.arg);
}
static void
composed(char *token, union tokenop u)
{
Symbol *sym;
sym = getsym(atoi(token+1));
push(&sym->type);
}
static void
getname(char *t, union tokenop u)
{
push((*++t) ? xstrdup(t) : NULL);
}
static void
symbol(char *token, union tokenop u)
{
Node *np = node(u.op & 0xFF);
Symbol *sym = getsym(atoi(token+1));
sclass = u.op >> 8;
np->u.sym = sym;
np->type = sym->type;
push(np);
}
static Type *
gettype(char *token)
{
struct decoc *dp;
dp = &optbl[*token];
if (!dp->parse)
error(ESYNTAX);
(*dp->parse)(token, dp->u);
return pop();
}
static void
constant(char *token, union tokenop u)
{
static char letters[] = "0123456789ABCDEF";
Node *np;
TUINT v;
unsigned c;
++token;
if (*token == '"') {
++token;
np = node(OSTRING);
np->type.flags = STRF;
np->type.size = strlen(token);
np->type.align = int8type.align;
np->u.s = xstrdup(token);
} else {
np = node(OCONST);
np->type = *gettype(token++);
for (v = 0; c = *token++; v += c) {
v <<= 4;
c = strchr(letters, c) - letters;
}
np->u.i = v;
}
push(np);
}
static void
assign(char *token, union tokenop u)
{
int subop;
Node *np = node(u.op);
switch (subop = *++token) {
case '+':
case '-':
case '*':
case '%':
case '/':
case 'l':
case 'r':
case '&':
case '|':
case '^':
case 'i':
case 'd':
++token;
subop = optbl[subop].u.op;
break;
default:
subop = 0;
break;
}
np->u.subop = subop;
np->type = *gettype(token);
np->right = pop();
np->left = pop();
push(np);
}
static void
ternary(char *token, union tokenop u)
{
Node *ask = node(OASK), *colon = node(OCOLON);
Type *tp = gettype(token+1);
colon->right = pop();
colon->left = pop();
ask->type = *tp;
ask->left = pop();
ask->right = colon;
push(ask);
}
static void
eval(char *tok)
{
struct decoc *dp;
do {
dp = &optbl[*tok];
if (!dp->parse)
break;
(*dp->parse)(tok, dp->u);
} while (tok = strtok(NULL, "\t\n"));
}
static int
nextline(void)
{
static char line[LINESIZ];
size_t len;
int c;
void (*fun)(void);
repeat:
++lineno;
if (!fgets(line, sizeof(line), stdin))
return 0;
if ((len = strlen(line)) == 0 || line[0] == '\n')
goto repeat;
if (line[len-1] != '\n')
error(len < sizeof(line)-1 ? ELNBLNE : ELNLINE);
line[len-1] = '\0';
c = *line;
eval(strtok(line, "\t\n"));
if ((fun = *optbl[c].eval) != NULL)
(*fun)();
if (sp != stack)
error(ESTACKA);
return 1;
}
static void
oreturn(char *token, union tokenop u)
{
Node *np = node(u.op);
if (token = strtok(NULL, "\t\n"))
eval(token);
if (!empty())
np->left = pop();
push(np);
}
/*
* Move np (which is a OCASE/ODEFAULT/OESWITCH) to be contigous with
* the last switch table. It is a bit ugly to touch directly curstmt
* here, but moving this function to node.c is worse, because we are
* putting knowledge of how the text is parsed into the node
* represtation module.
*/
static void
waft(Node *np)
{
Node *lastcase, *next;;
struct swtch *cur;
extern Node *curstmt;
if (swp == swtbl)
error(EWTACKU);
cur = swp - 1;
lastcase = cur->last;
next = lastcase->next;
np->next = next;
np->prev = lastcase;
if (next)
next->prev = np;
lastcase->next = np;
if (curstmt == cur->last)
curstmt = np;
cur->last = np;
cur->nr++;
}
static void
bswitch(char *token, union tokenop u)
{
struct swtch *cur;
Node *np = node(u.op);
if (swp == &swtbl[NR_BLOCK])
error(EWTACKO);
cur = swp++;
cur->nr = 0;
eval(strtok(NULL, "\t\n"));
np->left = pop();
push(cur->first = cur->last = np);
}
static void
eswitch(char *token, union tokenop u)
{
struct swtch *cur;
if (swp == swtbl)
error(EWTACKU);
jump(token, u);
waft(pop());
cur = --swp;
cur->first->u.i = cur->nr;
}
static void
ocase(char *token, union tokenop u)
{
jump(token, u);
waft(pop());
}
static void
jump(char *token, union tokenop u)
{
Node *aux, *np = node(u.op);
eval(strtok(NULL, "\t\n"));
if (u.op == OBRANCH || u.op == OCASE)
np->left = pop();
aux = pop();
np->u.sym = aux->u.sym;
delnode(aux);
push(np);
}
static void
loop(char *token, union tokenop u)
{
push(node(u.op));
}
static void
unary(char *token, union tokenop u)
{
Node *np = node(u.op);
np->type = *gettype(token+1);
np->left = pop();
np->right = NULL;
push(np);
}
static void
call(char *token, union tokenop u)
{
Node *np, *par, *fun = node(u.op);
for (par = NULL;; par = np) {
np = pop();
if (np->op != OPAR)
break;
np->right = par;
}
fun->type = *gettype(token+1);
fun->left = np;
fun->right = par;
push(fun);
}
static void
builtin(char *token, union tokenop u)
{
Node *np = node(u.op);
char *name;
unsigned subop, nchilds;
np->type = *gettype(token+1);
name = pop();
if (!strcmp("__builtin_va_arg", name)) {
nchilds = 1;
subop = BVA_ARG;
} else if (!strcmp("__builtin_va_start", name)) {
nchilds = 2;
subop = BVA_START;
} else if (!strcmp("__builtin_va_end", name)) {
nchilds = 1;
subop = BVA_END;
} else if (!strcmp("__builtin_va_copy", name)) {
nchilds = 2;
subop = BVA_COPY;
} else {
error(EBBUILT);;
}
np->u.subop = subop;
np->right = (nchilds == 2) ? pop() : NULL;
np->left = (nchilds != 0) ? pop() : NULL;
free(name);
push(np);
}
static void
binary(char *token, union tokenop u)
{
Node *np = node(u.op);
np->type = *gettype(token+1);
np->right = pop();
np->left = pop();
push(np);
}
static void
binit(char *token, union tokenop u)
{
ininit = 1;
}
static void
einit(char *token, union tokenop u)
{
ininit = 0;
endinit();
}
static void
endpars(void)
{
if (!curfun || !inpars)
error(ESYNTAX);
inpars = 0;
}
static void
aggregate(void)
{
Node *align, *size;
char *name;
Type *tp;
Symbol *sym;
align = pop();
size = pop();
name = pop();
tp = pop();
tp->size = size->u.i;
tp->align = align->u.i;
tp->flags = AGGRF;
/*
* type is the first field of Symbol so we can obtain the
* address of the symbol from the address of the type.
* We have to do this because composed returns the pointer
* to the type, but in this function we also need the
* symbol to store the name.
*/
sym = (Symbol *) tp;
sym->name = name;
delnode(align);
delnode(size);
}
static void
array(void)
{
Type *tp, *base;
Node *size;
size = pop();
base = pop();
tp = pop();
tp->flags = ARRF;
if (size->u.i > LONG_MAX/base->size)
error(EOVERFL);
tp->size = size->u.i * base->size;
tp->align = base->align;
delnode(size);
}
static void
decl(Symbol *sym)
{
Type *tp = &sym->type;
if (tp->flags & FUNF) {
lastfun = sym;
} else {
switch (sym->kind) {
case SEXTRN:
case SGLOB:
case SPRIV:
case SLOCAL:
defglobal(sym);
break;
case SAUTO:
case SREG:
if (!curfun)
error(ESYNTAX);
((inpars) ? defpar : defvar)(sym);
break;
default:
abort();
}
}
}
static void
vardecl(void)
{
Type *tp, *rp;
Node *np;
Symbol *sym;
char *name;
name = pop();
tp = pop();
if (tp->flags & FUNF)
rp = pop();
np = pop();
sym = np->u.sym;
/*
* We have to free sym->name because in tentative declarations
* we can have multiple declarations of the same symbol, and in
* this case our parser will allocate twice the memory
*/
free(sym->name);
sym->name = name;
sym->type = *tp;
if (tp->flags & FUNF)
sym->rtype = *rp;
sym->kind = sclass;
if (ininit)
sym->type.flags |= INITF;
decl(sym);
delnode(np);
}
static void
flddecl(void)
{
Node *off, *np;
char *name;
Type *tp;
Symbol *sym;
off = pop();
name = pop();
tp = pop();
np = pop();
sym = np->u.sym;
sym->u.off = off->u.i;
sym->name = name;
sym->type = *tp;
delnode(np);
delnode(off);
}
static void
labeldcl(void)
{
Node *np;
Symbol *sym;
np = pop();
np->op = ONOP;
sym = np->u.sym;
sym->kind = SLABEL;
sym->u.stmt = np;
np->label = sym;
addstmt(np, SETCUR);
}
static void
stmt(void)
{
Node *np;
if (empty())
return;
np = pop();
if (ininit) {
data(np);
deltree(np);
return;
}
addstmt(np, SETCUR);
}
static void
beginfun(void)
{
curfun = lastfun;
inpars = 1;
pushctx();
addstmt(node(OBFUN), SETCUR);
}
static void
endfun(void)
{
endf = 1;
addstmt(node(OEFUN), SETCUR);
}
void
parse(void)
{
cleannodes(); /* remove code of previous function */
popctx(); /* remove context of previous function */
curfun = NULL;
endf = 0;
while (!endf && nextline())
;
if (ferror(stdin))
error(EFERROR, strerror(errno));
}