go/src/runtime/runtime.c

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "runtime.h"

int32	panicking	= 0;
int32	maxround	= 8;

int32
gotraceback(void)
{
	byte *p;

	p = getenv("GOTRACEBACK");
	if(p == nil || p[0] == '\0')
		return 1;	// default is on
	return atoi(p);
}

void
sys·panicl(int32 lno)
{
	uint8 *sp;

	prints("\npanic ");
	sys·printpc(&lno);
	prints("\n");
	sp = (uint8*)&lno;
	if(gotraceback()){
		traceback(sys·getcallerpc(&lno), sp, g);
		tracebackothers(g);
	}
	panicking = 1;
	sys·Breakpoint();  // so we can grab it in a debugger
	sys_Exit(2);
}

void
sys·throwindex(void)
{
	throw("index out of range");
}

void
sys·throwreturn(void)
{
	throw("no return at end of a typed function");
}

void
throw(int8 *s)
{
	prints("throw: ");
	prints(s);
	prints("\n");
	*(int32*)0 = 0;
	sys_Exit(1);
}

void
mcpy(byte *t, byte *f, uint32 n)
{
	while(n > 0) {
		*t = *f;
		t++;
		f++;
		n--;
	}
}

int32
mcmp(byte *s1, byte *s2, uint32 n)
{
	uint32 i;
	byte c1, c2;

	for(i=0; i<n; i++) {
		c1 = s1[i];
		c2 = s2[i];
		if(c1 < c2)
			return -1;
		if(c1 > c2)
			return +1;
	}
	return 0;
}


void
mmov(byte *t, byte *f, uint32 n)
{
	if(t < f) {
		while(n > 0) {
			*t = *f;
			t++;
			f++;
			n--;
		}
	} else {
		t += n;
		f += n;
		while(n > 0) {
			t--;
			f--;
			*t = *f;
			n--;
		}
	}
}

byte*
mchr(byte *p, byte c, byte *ep)
{
	for(; p < ep; p++)
		if(*p == c)
			return p;
	return nil;
}

uint32
rnd(uint32 n, uint32 m)
{
	uint32 r;

	if(m > maxround)
		m = maxround;
	r = n % m;
	if(r)
		n += m-r;
	return n;
}

static int32	argc;
static uint8**	argv;

Array sys·Args;
Array sys·Envs;

void
args(int32 c, uint8 **v)
{
	argc = c;
	argv = v;
}

void
goargs(void)
{
	string* goargv;
	string* envv;
	int32 i, envc;

	goargv = (string*)argv;
	for (i=0; i<argc; i++)
		goargv[i] = gostring(argv[i]);
	sys·Args.array = (byte*)argv;
	sys·Args.nel = argc;
	sys·Args.cap = argc;

	envv = goargv + argc + 1;  // skip 0 at end of argv
	for (envc = 0; envv[envc] != 0; envc++)
		envv[envc] = gostring((uint8*)envv[envc]);
	sys·Envs.array = (byte*)envv;
	sys·Envs.nel = envc;
	sys·Envs.cap = envc;
}

byte*
getenv(int8 *s)
{
	int32 i, j, len;
	byte *v, *bs;
	string* envv;
	int32 envc;

	bs = (byte*)s;
	len = findnull(bs);
	envv = (string*)sys·Envs.array;
	envc = sys·Envs.nel;
	for(i=0; i<envc; i++){
		v = envv[i]->str;
		for(j=0; j<len; j++)
			if(bs[j] != v[j])
				goto nomatch;
		if(v[len] != '=')
			goto nomatch;
		return v+len+1;
	nomatch:;
	}
	return nil;
}


int32
atoi(byte *p)
{
	int32 n;

	n = 0;
	while('0' <= *p && *p <= '9')
		n = n*10 + *p++ - '0';
	return n;
}

void
check(void)
{
	int8 a;
	uint8 b;
	int16 c;
	uint16 d;
	int32 e;
	uint32 f;
	int64 g;
	uint64 h;
	float32 i;
	float64 j;
	void* k;
	uint16* l;

	if(sizeof(a) != 1) throw("bad a");
	if(sizeof(b) != 1) throw("bad b");
	if(sizeof(c) != 2) throw("bad c");
	if(sizeof(d) != 2) throw("bad d");
	if(sizeof(e) != 4) throw("bad e");
	if(sizeof(f) != 4) throw("bad f");
	if(sizeof(g) != 8) throw("bad g");
	if(sizeof(h) != 8) throw("bad h");
	if(sizeof(i) != 4) throw("bad i");
	if(sizeof(j) != 8) throw("bad j");
	if(sizeof(k) != 8) throw("bad k");
	if(sizeof(l) != 8) throw("bad l");
//	prints(1"check ok\n");

	uint32 z;
	z = 1;
	if(!cas(&z, 1, 2))
		throw("cas1");
	if(z != 2)
		throw("cas2");

	z = 4;
	if(cas(&z, 5, 6))
		throw("cas3");
	if(z != 4)
		throw("cas4");

	initsig();
}

/*
 * map and chan helpers for
 * dealing with unknown types
 */
static uint64
memhash(uint32 s, void *a)
{
	byte *b;
	uint64 hash;

	b = a;
	hash = 33054211828000289ULL;
	while(s > 0) {
		hash = (hash ^ *b) * 23344194077549503ULL;
		b++;
		s--;
	}
	return hash;
}

static uint32
memequal(uint32 s, void *a, void *b)
{
	byte *ba, *bb;
	uint32 i;

	ba = a;
	bb = b;
	for(i=0; i<s; i++)
		if(ba[i] != bb[i])
			return 0;
	return 1;
}

static void
memprint(uint32 s, void *a)
{
	uint64 v;

	v = 0xbadb00b;
	switch(s) {
	case 1:
		v = *(uint8*)a;
		break;
	case 2:
		v = *(uint16*)a;
		break;
	case 4:
		v = *(uint32*)a;
		break;
	case 8:
		v = *(uint64*)a;
		break;
	}
	sys·printint(v);
}

static void
memcopy(uint32 s, void *a, void *b)
{
	byte *ba, *bb;
	uint32 i;

	ba = a;
	bb = b;
	if(bb == nil) {
		for(i=0; i<s; i++)
			ba[i] = 0;
		return;
	}
	for(i=0; i<s; i++)
		ba[i] = bb[i];
}

static uint64
strhash(uint32 s, string *a)
{
	USED(s);
	if(*a == nil)
		return memhash(emptystring->len, emptystring->str);
	return memhash((*a)->len, (*a)->str);
}

static uint32
strequal(uint32 s, string *a, string *b)
{
	USED(s);
	return cmpstring(*a, *b) == 0;
}

static void
strprint(uint32 s, string *a)
{
	USED(s);
	sys·printstring(*a);
}

static uint64
interhash(uint32 s, Iface *a)
{
	USED(s);
	return ifacehash(*a);
}

static void
interprint(uint32 s, Iface *a)
{
	USED(s);
	sys·printinter(*a);
}

static uint32
interequal(uint32 s, Iface *a, Iface *b)
{
	USED(s);
	return ifaceeq(*a, *b);
}

uint64
nohash(uint32 s, void *a)
{
	USED(s);
	USED(a);
	throw("hash of unhashable type");
	return 0;
}

uint32
noequal(uint32 s, void *a, void *b)
{
	USED(s);
	USED(a);
	USED(b);
	throw("comparing uncomparable types");
	return 0;
}

static void
noprint(uint32 s, void *a)
{
	USED(s);
	USED(a);
	throw("print of unprintable type");
}

static void
nocopy(uint32 s, void *a, void *b)
{
	USED(s);
	USED(a);
	USED(b);
	throw("copy of uncopyable type");
}

Alg
algarray[] =
{
[AMEM]	{ memhash, memequal, memprint, memcopy },
[ANOEQ]	{ nohash, noequal, memprint, memcopy },
[ASTRING]	{ strhash, strequal, strprint, memcopy },
[AINTER]		{ interhash, interequal, interprint, memcopy },
[AFAKE]	{ nohash, noequal, noprint, nocopy },
};