* Copyright (c) 2010, 2013 The NetBSD Foundation, Inc.

/*-
* Copyright (c) 2010, 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by David A. Holland.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "union.h"
#include "array.h"
#include "mode.h"
#include "place.h"
#include "macro.h"
#include "output.h"

struct expansionitem {
enum { EI_STRING, EI_PARAM, EI_FILE, EI_LINE } itemtype;
union {
char *ei_string; /* for EI_STRING */
unsigned ei_param; /* for EI_PARAM */
} UN;
};
DECLARRAY(expansionitem, static UNUSED);
DEFARRAY(expansionitem, static);

#ifdef NEED_UNION_ACCESSORS
#define ei_string un.ei_string
#define ei_param un.ei_param
#endif

struct macro {
struct place defplace;
struct place expansionplace;
unsigned hash;
char *name;
bool hasparams;
struct stringarray params;
struct expansionitemarray expansion;
bool inuse;
};
DECLARRAY(macro, static UNUSED);
DEFARRAY(macro, static);
DECLARRAY(macroarray, static UNUSED);
DEFARRAY(macroarray, static);

static struct macroarrayarray macros;
static unsigned total_macros;
static unsigned hashmask;

////////////////////////////////////////////////////////////
// macro structure ops

static
struct expansionitem *
expansionitem_create_string(const char *string)
{
struct expansionitem *ei;

ei = domalloc(sizeof(*ei));
ei->itemtype = EI_STRING;
ei->ei_string = dostrdup(string);
return ei;
}

static
struct expansionitem *
expansionitem_create_stringlen(const char *string, size_t len)
{
struct expansionitem *ei;

ei = domalloc(sizeof(*ei));
ei->itemtype = EI_STRING;
ei->ei_string = dostrndup(string, len);
return ei;
}

static
struct expansionitem *
expansionitem_create_param(unsigned param)
{
struct expansionitem *ei;

ei = domalloc(sizeof(*ei));
ei->itemtype = EI_PARAM;
ei->ei_param = param;
return ei;
}

static
struct expansionitem *
expansionitem_create_file(void)
{
struct expansionitem *ei;

ei = domalloc(sizeof(*ei));
ei->itemtype = EI_FILE;
return ei;
}

static
struct expansionitem *
expansionitem_create_line(void)
{
struct expansionitem *ei;

ei = domalloc(sizeof(*ei));
ei->itemtype = EI_LINE;
return ei;
}

static
void
expansionitem_destroy(struct expansionitem *ei)
{
switch (ei->itemtype) {
case EI_STRING:
dostrfree(ei->ei_string);
break;
case EI_PARAM:
case EI_FILE:
case EI_LINE:
break;
}
dofree(ei, sizeof(*ei));
}

static
bool
expansionitem_eq(const struct expansionitem *ei1,
const struct expansionitem *ei2)
{
if (ei1->itemtype != ei2->itemtype) {
return false;
}
switch (ei1->itemtype) {
case EI_STRING:
if (strcmp(ei1->ei_string, ei2->ei_string) != 0) {
return false;
}
break;
case EI_PARAM:
if (ei1->ei_param != ei2->ei_param) {
return false;
}
break;
case EI_FILE:
case EI_LINE:
break;
}
return true;
}

static
struct macro *
macro_create(struct place *p1, const char *name, unsigned hash,
struct place *p2)
{
struct macro *m;

m = domalloc(sizeof(*m));
m->defplace = *p1;
m->expansionplace = *p2;
m->hash = hash;
m->name = dostrdup(name);
m->hasparams = false;
stringarray_init(&m->params);
expansionitemarray_init(&m->expansion);
m->inuse = false;
return m;
}

DESTROYALL_ARRAY(expansionitem, );

static
void
macro_destroy(struct macro *m)
{
expansionitemarray_destroyall(&m->expansion);
expansionitemarray_cleanup(&m->expansion);
dostrfree(m->name);
dofree(m, sizeof(*m));
}

static
bool
macro_eq(const struct macro *m1, const struct macro *m2)
{
unsigned num1, num2, i;
struct expansionitem *ei1, *ei2;
const char *p1, *p2;

if (strcmp(m1->name, m2->name) != 0) {
return false;
}

if (m1->hasparams != m2->hasparams) {
return false;
}

num1 = expansionitemarray_num(&m1->expansion);
num2 = expansionitemarray_num(&m2->expansion);
if (num1 != num2) {
return false;
}

for (i=0; i<num1; i++) {
ei1 = expansionitemarray_get(&m1->expansion, i);
ei2 = expansionitemarray_get(&m2->expansion, i);
if (!expansionitem_eq(ei1, ei2)) {
return false;
}
}

num1 = stringarray_num(&m1->params);
num2 = stringarray_num(&m2->params);
if (num1 != num2) {
return false;
}

for (i=0; i<num1; i++) {
p1 = stringarray_get(&m1->params, i);
p2 = stringarray_get(&m2->params, i);
if (strcmp(p1, p2) != 0) {
return false;
}
}
return true;
}

////////////////////////////////////////////////////////////
// macro table

/*
* Unless I've screwed up, this is something called Fletcher's Checksum
* that showed up in Dr. Dobbs in, according to my notes, May 1992. The
* implementation is new.
*/
static
unsigned
hashfunc(const char *s, size_t len)
{
uint16_t x1, x2, a;
size_t i;

x1 = (uint16_t) (len >> 16);
x2 = (uint16_t) (len);
if (x1==0) {
x1++;
}
if (x2==0) {
x2++;
}

for (i=0; i<len; i+=2) {
if (i==len-1) {
a = (unsigned char)s[i];
/* don't run off the end of the array */
}
else {
a = (unsigned char)s[i] +
((uint16_t)(unsigned char)s[i+1] << 8);
}
x1 += a;
if (x1 < a) {
x1++;
}
x2 += x1;
if (x2 < x1) {
x2++;
}
}

x1 ^= 0xffff;
x2 ^= 0xffff;
return ((uint32_t)x2)*65535U + x1;
}

static
void
macrotable_init(void)
{
unsigned i;

macroarrayarray_init(&macros);
macroarrayarray_setsize(&macros, 4);
for (i=0; i<4; i++) {
macroarrayarray_set(&macros, i, NULL);
}
total_macros = 0;
hashmask = 0x3;
}

DESTROYALL_ARRAY(macro, );

static
void
macrotable_cleanup(void)
{
struct macroarray *bucket;
unsigned numbuckets, i;

numbuckets = macroarrayarray_num(&macros);
for (i=0; i<numbuckets; i++) {
bucket = macroarrayarray_get(&macros, i);
if (bucket != NULL) {
macroarray_destroyall(bucket);
macroarray_destroy(bucket);
}
}
macroarrayarray_setsize(&macros, 0);
macroarrayarray_cleanup(&macros);
}

static
struct macro *
macrotable_findlen(const char *name, size_t len, bool remove_it)
{
unsigned hash;
struct macroarray *bucket;
struct macro *m, *m2;
unsigned i, num;
size_t mlen;

hash = hashfunc(name, len);
bucket = macroarrayarray_get(&macros, hash & hashmask);
if (bucket == NULL) {
return NULL;
}
num = macroarray_num(bucket);
for (i=0; i<num; i++) {
m = macroarray_get(bucket, i);
if (hash != m->hash) {
continue;
}
mlen = strlen(m->name);
if (len == mlen && !memcmp(name, m->name, len)) {
if (remove_it) {
if (i < num-1) {
m2 = macroarray_get(bucket, num-1);
macroarray_set(bucket, i, m2);
}
macroarray_setsize(bucket, num-1);
total_macros--;
}
return m;
}
}
return NULL;
}

static
struct macro *
macrotable_find(const char *name, bool remove_it)
{
return macrotable_findlen(name, strlen(name), remove_it);
}

static
void
macrotable_rehash(void)
{
struct macroarray *newbucket, *oldbucket;
struct macro *m;
unsigned newmask, tossbit;
unsigned numbuckets, i;
unsigned oldnum, j, k;

numbuckets = macroarrayarray_num(&macros);
macroarrayarray_setsize(&macros, numbuckets*2);

assert(hashmask == numbuckets - 1);
newmask = (hashmask << 1) | 1U;
tossbit = newmask & ~hashmask;
hashmask = newmask;

for (i=0; i<numbuckets; i++) {
newbucket = NULL;
oldbucket = macroarrayarray_get(&macros, i);
if (oldbucket == NULL) {
macroarrayarray_set(&macros, numbuckets + i, NULL);
continue;
}
oldnum = macroarray_num(oldbucket);
for (j=0; j<oldnum; j++) {
m = macroarray_get(oldbucket, j);
if (m->hash & tossbit) {
if (newbucket == NULL) {
newbucket = macroarray_create();
}
macroarray_set(oldbucket, j, NULL);
macroarray_add(newbucket, m, NULL);
}
}
for (j=k=0; j<oldnum; j++) {
m = macroarray_get(oldbucket, j);
if (m != NULL) {
if (k < j) {
macroarray_set(oldbucket, k, m);
}
k++;
}
}
macroarray_setsize(oldbucket, k);
macroarrayarray_set(&macros, numbuckets + i, newbucket);
}
}

static
void
macrotable_add(struct macro *m)
{
unsigned hash;
struct macroarray *bucket;
unsigned numbuckets;

numbuckets = macroarrayarray_num(&macros);
if (total_macros > 0 && total_macros / numbuckets > 9) {
macrotable_rehash();
}

hash = hashfunc(m->name, strlen(m->name));
bucket = macroarrayarray_get(&macros, hash & hashmask);
if (bucket == NULL) {
bucket = macroarray_create();
macroarrayarray_set(&macros, hash & hashmask, bucket);
}
macroarray_add(bucket, m, NULL);
total_macros++;
}

////////////////////////////////////////////////////////////
// external macro definition interface

static
struct macro *
macro_define_common_start(struct place *p1, const char *macro,
struct place *p2)
{
struct macro *m;
unsigned hash;

if (!is_identifier(macro)) {
complain(p1, "Invalid macro name %s", macro);
complain_fail();
}

hash = hashfunc(macro, strlen(macro));
m = macro_create(p1, macro, hash, p2);
return m;
}

static
void
macro_define_common_end(struct macro *m)
{
struct macro *oldm;
bool ok;

oldm = macrotable_find(m->name, false);
if (oldm != NULL) {
ok = macro_eq(m, oldm);
if (ok) {
/* in traditional cpp this is silent */
//complain(&m->defplace,
// "Warning: redefinition of %s", m->name);
//complain(&oldm->defplace,
// "Previous definition was here");
//if (mode.werror) {
// complain_fail();
//}
} else {
complain(&m->defplace,
"Warning: non-identical redefinition of %s",
m->name);
complain(&oldm->defplace,
"Previous definition was here");
/* in traditional cpp this is not fatal */
if (mode.werror) {
complain_fail();
}
}
macro_destroy(m);
return;
}
macrotable_add(m);
}

static
void
macro_parse_parameters(struct macro *m, struct place *p, const char *params)
{
size_t len;
const char *s;
char *param;

while (params != NULL) {
len = strspn(params, ws);
params += len;
place_addcolumns(p, len);
s = strchr(params, ',');
if (s) {
len = s-params;
param = dostrndup(params, len);
s++;
} else {
len = strlen(params);
param = dostrndup(params, len);
}
notrailingws(param, strlen(param));
if (!is_identifier(param)) {
complain(p, "Invalid macro parameter name %s", param);
complain_fail();
} else {
stringarray_add(&m->params, param, NULL);
}
params = s;
place_addcolumns(p, len);
}
}

static
bool
isparam(struct macro *m, const char *name, size_t len, unsigned *num_ret)
{
unsigned num, i;
const char *param;

num = stringarray_num(&m->params);
for (i=0; i<num; i++) {
param = stringarray_get(&m->params, i);
if (strlen(param) == len && !memcmp(name, param, len)) {
*num_ret = i;
return true;
}
}
return false;
}

static
void
macro_parse_expansion(struct macro *m, const char *buf)
{
size_t blockstart, wordstart, pos;
struct expansionitem *ei;
unsigned param;

pos = blockstart = 0;
while (buf[pos] != '\0') {
pos += strspn(buf+pos, ws);
if (strchr(alnum, buf[pos])) {
wordstart = pos;
pos += strspn(buf+pos, alnum);
if (isparam(m, buf+wordstart, pos-wordstart, &param)) {
if (wordstart > blockstart) {
ei = expansionitem_create_stringlen(
buf + blockstart,
wordstart - blockstart);
expansionitemarray_add(&m->expansion,
ei, NULL);
}
ei = expansionitem_create_param(param);
expansionitemarray_add(&m->expansion, ei,NULL);
blockstart = pos;
continue;
}
continue;
}
pos++;
}
if (pos > blockstart) {
ei = expansionitem_create_stringlen(buf + blockstart,
pos - blockstart);
expansionitemarray_add(&m->expansion, ei, NULL);
}
}

void
macro_define_plain(struct place *p1, const char *macro,
struct place *p2, const char *expansion)
{
struct macro *m;
struct expansionitem *ei;

m = macro_define_common_start(p1, macro, p2);
ei = expansionitem_create_string(expansion);
expansionitemarray_add(&m->expansion, ei, NULL);
macro_define_common_end(m);
}

void
macro_define_params(struct place *p1, const char *macro,
struct place *p2, const char *params,
struct place *p3, const char *expansion)
{
struct macro *m;

m = macro_define_common_start(p1, macro, p3);
m->hasparams = true;
macro_parse_parameters(m, p2, params);
macro_parse_expansion(m, expansion);
macro_define_common_end(m);
}

void
macro_define_magic(struct place *p, const char *macro)
{
struct macro *m;
struct expansionitem *ei;

m = macro_define_common_start(p, macro, p);
if (!strcmp(macro, "__FILE__")) {
ei = expansionitem_create_file();
}
else {
assert(!strcmp(macro, "__LINE__"));
ei = expansionitem_create_line();
}
expansionitemarray_add(&m->expansion, ei, NULL);
macro_define_common_end(m);
}

void
macro_undef(const char *macro)
{
struct macro *m;

m = macrotable_find(macro, true);
if (m) {
macro_destroy(m);
}
}

bool
macro_isdefined(const char *macro)
{
struct macro *m;

m = macrotable_find(macro, false);
return m != NULL;
}

////////////////////////////////////////////////////////////
// macro expansion

struct expstate {
bool honordefined;
enum { ES_NORMAL, ES_WANTLPAREN, ES_NOARG, ES_HAVEARG } state;
struct macro *curmacro;
struct stringarray args;
unsigned argparens;

bool tobuf;
char *buf;
size_t bufpos, bufmax;
};

static struct expstate mainstate;

static void doexpand(struct expstate *es, struct place *p,
const char *buf, size_t len);

static
void
expstate_init(struct expstate *es, bool tobuf, bool honordefined)
{
es->honordefined = honordefined;
es->state = ES_NORMAL;
es->curmacro = NULL;
stringarray_init(&es->args);
es->argparens = 0;
es->tobuf = tobuf;
es->buf = NULL;
es->bufpos = 0;
es->bufmax = 0;
}

static
void
expstate_cleanup(struct expstate *es)
{
assert(es->state == ES_NORMAL);
stringarray_cleanup(&es->args);
if (es->buf) {
dofree(es->buf, es->bufmax);
}
}

static
void
expstate_destroyargs(struct expstate *es)
{
unsigned i, num;

num = stringarray_num(&es->args);
for (i=0; i<num; i++) {
dostrfree(stringarray_get(&es->args, i));
}
stringarray_setsize(&es->args, 0);
}

static
void
expand_send(struct expstate *es, struct place *p, const char *buf, size_t len)
{
size_t oldmax;

if (es->tobuf) {
assert(es->bufpos <= es->bufmax);
if (es->bufpos + len > es->bufmax) {
oldmax = es->bufmax;
if (es->bufmax == 0) {
es->bufmax = 64;
}
while (es->bufpos + len > es->bufmax) {
es->bufmax *= 2;
}
es->buf = dorealloc(es->buf, oldmax, es->bufmax);
}
memcpy(es->buf + es->bufpos, buf, len);
es->bufpos += len;
assert(es->bufpos <= es->bufmax);
} else {
output(p, buf, len);
}
}

static
void
expand_send_eof(struct expstate *es, struct place *p)
{
if (es->tobuf) {
expand_send(es, p, "", 1);
es->bufpos--;
} else {
output_eof();
}
}

static
void
expand_newarg(struct expstate *es, const char *buf, size_t len)
{
char *text;

text = dostrndup(buf, len);
stringarray_add(&es->args, text, NULL);
}

static
void
expand_appendarg(struct expstate *es, const char *buf, size_t len)
{
unsigned num;
char *text;
size_t oldlen;

num = stringarray_num(&es->args);
assert(num > 0);

text = stringarray_get(&es->args, num - 1);
oldlen = strlen(text);
text = dorealloc(text, oldlen + 1, oldlen + len + 1);
memcpy(text + oldlen, buf, len);
text[oldlen+len] = '\0';
stringarray_set(&es->args, num - 1, text);
}

static
char *
expand_substitute(struct place *p, struct expstate *es)
{
struct expansionitem *ei;
unsigned i, num;
size_t len;
char *arg;
char *ret;
unsigned numargs, numparams;
char numbuf[64];

numargs = stringarray_num(&es->args);
numparams = stringarray_num(&es->curmacro->params);

if (numargs == 0 && numparams == 1) {
/* no arguments <=> one empty argument */
stringarray_add(&es->args, dostrdup(""), NULL);
numargs++;
}
if (numargs != numparams) {
complain(p, "Wrong number of arguments for macro %s; "
"found %u, expected %u",
es->curmacro->name, numargs, numparams);
complain_fail();
while (numargs < numparams) {
stringarray_add(&es->args, dostrdup(""), NULL);
numargs++;
}
}

len = 0;
num = expansionitemarray_num(&es->curmacro->expansion);
for (i=0; i<num; i++) {
ei = expansionitemarray_get(&es->curmacro->expansion, i);
switch (ei->itemtype) {
case EI_STRING:
len += strlen(ei->ei_string);
break;
case EI_PARAM:
arg = stringarray_get(&es->args, ei->ei_param);
len += strlen(arg);
break;
case EI_FILE:
len += strlen(place_getname(p)) + 2;
break;
case EI_LINE:
len += snprintf(numbuf, sizeof(numbuf), "%u", p->line);
break;
}
}

ret = domalloc(len+1);
*ret = '\0';
for (i=0; i<num; i++) {
ei = expansionitemarray_get(&es->curmacro->expansion, i);
switch (ei->itemtype) {
case EI_STRING:
strcat(ret, ei->ei_string);
break;
case EI_PARAM:
arg = stringarray_get(&es->args, ei->ei_param);
strcat(ret, arg);
break;
case EI_FILE:
strcat(ret, "\"");
strcat(ret, place_getname(p));
strcat(ret, "\"");
break;
case EI_LINE:
snprintf(numbuf, sizeof(numbuf), "%u", p->line);
strcat(ret, numbuf);
break;
}
}

return ret;
}

static
void
expand_domacro(struct expstate *es, struct place *p)
{
struct macro *m;
const char *name, *val;
char *newbuf, *newbuf2;

if (es->curmacro == NULL) {
/* defined() */
if (stringarray_num(&es->args) != 1) {
complain(p, "Too many arguments for defined()");
complain_fail();
expand_send(es, p, "0", 1);
return;
}
name = stringarray_get(&es->args, 0);
m = macrotable_find(name, false);
val = (m != NULL) ? "1" : "0";
debuglog(p, "defined(%s): %s", name, val);
expand_send(es, p, val, 1);
expstate_destroyargs(es);
return;
}

m = es->curmacro;
assert(m->inuse == false);
m->inuse = true;

debuglog(p, "Expanding macro %s", m->name);
newbuf = expand_substitute(p, es);
debuglog(p, "Substituting for %s: %s", m->name, newbuf);

newbuf2 = macroexpand(p, newbuf, strlen(newbuf), false);
dostrfree(newbuf);
expstate_destroyargs(es);
debuglog(p, "Complete expansion for %s: %s", m->name, newbuf2);

doexpand(es, p, newbuf2, strlen(newbuf2));
dostrfree(newbuf2);

m->inuse = false;
}

/*
* The traditional behavior if a function-like macro appears without
* arguments is to pretend it isn't a macro; that is, just emit its
* name.
*/
static
void
expand_missingargs(struct expstate *es, struct place *p, bool needspace)
{
if (es->curmacro == NULL) {
/* defined */
expand_send(es, p, "defined", 7);
return;
}
expand_send(es, p, es->curmacro->name, strlen(es->curmacro->name));
/* send a space in case we ate whitespace after the macro name */
if (needspace) {
expand_send(es, p, " ", 1);
}
}

static
void
expand_got_ws(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
switch (es->state) {
case ES_NORMAL:
expand_send(es, p, buf, len);
break;
case ES_WANTLPAREN:
/* XXX notyet */
//expand_send(es, p, buf, len);
break;
case ES_NOARG:
expand_newarg(es, buf, len);
es->state = ES_HAVEARG;
break;
case ES_HAVEARG:
expand_appendarg(es, buf, len);
break;
}
}

static
void
expand_got_word(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
struct macro *m;

switch (es->state) {
case ES_NORMAL:
if (es->honordefined &&
len == 7 && !memcmp(buf, "defined", 7)) {
es->curmacro = NULL;
es->state = ES_WANTLPAREN;
break;
}
m = macrotable_findlen(buf, len, false);
if (m == NULL || m->inuse) {
expand_send(es, p, buf, len);
} else if (!m->hasparams) {
es->curmacro = m;
expand_domacro(es, p);
} else {
es->curmacro = m;
es->state = ES_WANTLPAREN;
}
break;
case ES_WANTLPAREN:
if (es->curmacro != NULL) {
expand_missingargs(es, p, true);
es->state = ES_NORMAL;
/* try again */
expand_got_word(es, p, buf, len);
} else {
/* "defined foo" means "defined(foo)" */
expand_newarg(es, buf, len);
es->state = ES_NORMAL;
expand_domacro(es, p);
}
break;
case ES_NOARG:
expand_newarg(es, buf, len);
es->state = ES_HAVEARG;
break;
case ES_HAVEARG:
expand_appendarg(es, buf, len);
break;
}
}

static
void
expand_got_lparen(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
switch (es->state) {
case ES_NORMAL:
expand_send(es, p, buf, len);
break;
case ES_WANTLPAREN:
es->state = ES_NOARG;
break;
case ES_NOARG:
expand_newarg(es, buf, len);
es->state = ES_HAVEARG;
es->argparens++;
break;
case ES_HAVEARG:
expand_appendarg(es, buf, len);
es->argparens++;
break;
}
}

static
void
expand_got_rparen(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
switch (es->state) {
case ES_NORMAL:
expand_send(es, p, buf, len);
break;
case ES_WANTLPAREN:
expand_missingargs(es, p, false);
es->state = ES_NORMAL;
/* try again */
expand_got_rparen(es, p, buf, len);
break;
case ES_NOARG:
assert(es->argparens == 0);
if (stringarray_num(&es->args) > 0) {
/* we are after a comma; enter an empty argument */
expand_newarg(es, buf, 0);
}
es->state = ES_NORMAL;
expand_domacro(es, p);
break;
case ES_HAVEARG:
if (es->argparens > 0) {
es->argparens--;
expand_appendarg(es, buf, len);
} else {
es->state = ES_NORMAL;
expand_domacro(es, p);
}
break;
}
}

static
void
expand_got_comma(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
switch (es->state) {
case ES_NORMAL:
expand_send(es, p, buf, len);
break;
case ES_WANTLPAREN:
expand_missingargs(es, p, false);
es->state = ES_NORMAL;
/* try again */
expand_got_comma(es, p, buf, len);
break;
case ES_NOARG:
assert(es->argparens == 0);
expand_newarg(es, buf, 0);
break;
case ES_HAVEARG:
if (es->argparens > 0) {
expand_appendarg(es, buf, len);
} else {
es->state = ES_NOARG;
}
break;
}
}

static
void
expand_got_other(struct expstate *es, struct place *p,
const char *buf, size_t len)
{
switch (es->state) {
case ES_NORMAL:
expand_send(es, p, buf, len);
break;
case ES_WANTLPAREN:
expand_missingargs(es, p, false);
es->state = ES_NORMAL;
/* try again */
expand_got_other(es, p, buf, len);
break;
case ES_NOARG:
expand_newarg(es, buf, len);
es->state = ES_HAVEARG;
break;
case ES_HAVEARG:
expand_appendarg(es, buf, len);
break;
}
}

static
void
expand_got_eof(struct expstate *es, struct place *p)
{
switch (es->state) {
case ES_NORMAL:
break;
case ES_WANTLPAREN:
expand_missingargs(es, p, false);
break;
case ES_NOARG:
case ES_HAVEARG:
if (es->curmacro) {
complain(p, "Unclosed argument list for macro %s",
es->curmacro->name);
} else {
complain(p, "Unclosed argument list for defined()");
}
complain_fail();
expstate_destroyargs(es);
break;
}
expand_send_eof(es, p);
es->state = ES_NORMAL;
es->curmacro = NULL;
es->argparens = 0;
}

static
void
doexpand(struct expstate *es, struct place *p, const char *buf, size_t len)
{
char *s;
size_t x;
bool inquote = false;
char quote = '\0';

while (len > 0) {
x = strspn(buf, ws);
if (x > len) {
/* XXX gross, need strnspn */
x = len;
}

if (x > 0) {
expand_got_ws(es, p, buf, x);
buf += x;
len -= x;
continue;
}

x = strspn(buf, alnum);
if (x > len) {
/* XXX gross, need strnspn */
x = len;
}

if (!inquote && x > 0) {
expand_got_word(es, p, buf, x);
buf += x;
len -= x;
continue;
}

if (!inquote && len > 1 && buf[0] == '/' && buf[1] == '*') {
s = strstr(buf, "*/");
if (s) {
x = s - buf;
} else {
x = len;
}
expand_got_ws(es, p, buf, x);
buf += x;
len -= x;
continue;
}

if (!inquote && buf[0] == '(') {
expand_got_lparen(es, p, buf, 1);
buf++;
len--;
continue;
}

if (!inquote && buf[0] == ')') {
expand_got_rparen(es, p, buf, 1);
buf++;
len--;
continue;
}

if (!inquote && buf[0] == ',') {
expand_got_comma(es, p, buf, 1);
buf++;
len--;
continue;
}

if (len > 1 && buf[0] == '\\' &&
(buf[1] == '"' || buf[1] == '\'')) {
expand_got_other(es, p, buf, 2);
buf += 2;
len -= 2;
continue;
}
if (!inquote && (buf[0] == '"' || buf[0] == '\'')) {
inquote = true;
quote = buf[0];
} else if (inquote && buf[0] == quote) {
inquote = false;
}

expand_got_other(es, p, buf, 1);
buf++;
len--;
}
}

char *
macroexpand(struct place *p, const char *buf, size_t len, bool honordefined)
{
struct expstate es;
char *ret;

expstate_init(&es, true, honordefined);
doexpand(&es, p, buf, len);
expand_got_eof(&es, p);

/* trim to fit, so the malloc debugging won't complain */
es.buf = dorealloc(es.buf, es.bufmax, strlen(es.buf) + 1);

ret = es.buf;
es.buf = NULL;
es.bufpos = es.bufmax = 0;

expstate_cleanup(&es);

return ret;
}

void
macro_sendline(struct place *p, const char *buf, size_t len)
{
doexpand(&mainstate, p, buf, len);
switch (mainstate.state) {
case ES_NORMAL:
/*
* If we were sent a blank line, don't emit a newline
* for it. This matches the prior behavior of tradcpp.
*/
if (len > 0) {
output(p, "\n", 1);
}
break;
case ES_WANTLPAREN:
case ES_NOARG:
case ES_HAVEARG:
/*
* Apparently to match gcc's -traditional behavior we
* need to emit a space for each newline that appears
* while processing macro args.
*/
expand_got_ws(&mainstate, p, " ", 1);
break;
}
}

void
macro_sendeof(struct place *p)
{
expand_got_eof(&mainstate, p);
}

////////////////////////////////////////////////////////////
// module initialization

void
macros_init(void)
{
macrotable_init();
expstate_init(&mainstate, false, false);
}

void
macros_cleanup(void)
{
expstate_cleanup(&mainstate);
macrotable_cleanup();
}