src/cmd/gc/pgen.c

// Copyright 2011 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.

#undef	EXTERN
#define	EXTERN
#include "gg.h"
#include "opt.h"

void
compile(Node *fn)
{
	Plist *pl;
	Node nod1, *n;
	Prog *ptxt;
	int32 lno;
	Type *t;
	Iter save;

	if(newproc == N) {
		newproc = sysfunc("newproc");
		deferproc = sysfunc("deferproc");
		deferreturn = sysfunc("deferreturn");
		panicindex = sysfunc("panicindex");
		panicslice = sysfunc("panicslice");
		throwreturn = sysfunc("throwreturn");
	}

	if(fn->nbody == nil)
		return;

	// set up domain for labels
	clearlabels();

	lno = setlineno(fn);

	curfn = fn;
	dowidth(curfn->type);

	if(curfn->type->outnamed) {
		// add clearing of the output parameters
		t = structfirst(&save, getoutarg(curfn->type));
		while(t != T) {
			if(t->nname != N) {
				n = nod(OAS, t->nname, N);
				typecheck(&n, Etop);
				curfn->nbody = concat(list1(n), curfn->nbody);
			}
			t = structnext(&save);
		}
	}

	hasdefer = 0;
	walk(curfn);
	if(nerrors != 0 || isblank(curfn->nname))
		goto ret;

	allocparams();

	continpc = P;
	breakpc = P;

	pl = newplist();
	pl->name = curfn->nname;

	setlineno(curfn);

	nodconst(&nod1, types[TINT32], 0);
	ptxt = gins(ATEXT, curfn->nname, &nod1);
	afunclit(&ptxt->from);

	ginit();
	genlist(curfn->enter);

	retpc = nil;
	if(hasdefer || curfn->exit) {
		Prog *p1;

		p1 = gjmp(nil);
		retpc = gjmp(nil);
		patch(p1, pc);
	}

	genlist(curfn->nbody);
	gclean();
	checklabels();
	if(nerrors != 0)
		goto ret;
	if(curfn->endlineno)
		lineno = curfn->endlineno;

	if(curfn->type->outtuple != 0)
		ginscall(throwreturn, 0);

	if(retpc)
		patch(retpc, pc);
	ginit();
	if(hasdefer)
		ginscall(deferreturn, 0);
	if(curfn->exit)
		genlist(curfn->exit);
	gclean();
	if(nerrors != 0)
		goto ret;
	pc->as = ARET;	// overwrite AEND
	pc->lineno = lineno;

	if(!debug['N'] || debug['R'] || debug['P']) {
		regopt(ptxt);
	}

	defframe(ptxt);

	if(debug['f'])
		frame(0);

ret:
	lineno = lno;
}