dec.cc

/*****
 * dec.cc
 * Andy Hammerlindl 2002/8/29
 *
 * Represents the abstract syntax tree for declarations in the language.
 * Also included is an abstract syntax for types as they are most often
 * used with declarations.
 *****/

#include "errormsg.h"
#include "coenv.h"
#include "dec.h"
#include "fundec.h"
#include "newexp.h"
#include "stm.h"
#include "exp.h"
#include "modifier.h"
#include "runtime.h"
#include "parser.h"

namespace absyntax {

using namespace trans;
using namespace types;

using mem::list;

trans::tyEntry *ty::transAsTyEntry(coenv &e, record *where)
{
  return new trans::tyEntry(trans(e, false), 0, where, getPos());
}


void nameTy::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "nameTy",indent);

  id->prettyprint(out, indent+1);
}

types::ty *nameTy::trans(coenv &e, bool tacit)
{
  return id->typeTrans(e, tacit);
}

trans::tyEntry *nameTy::transAsTyEntry(coenv &e, record *)
{
  return id->tyEntryTrans(e);
}


void dimensions::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "dimensions (" << depth << ")\n";
}

types::array *dimensions::truetype(types::ty *base)
{
  if (base->kind == ty_void) {
    em.error(getPos());
    em << "cannot declare array of type void";
  }

  assert(depth >= 1);
  size_t d=depth;
  types::array *a=new types::array(base); d--;
  for (; d > 0; d--) {
    a = new types::array(a);
  }
  return a;
}


void arrayTy::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "arrayTy",indent);

  cell->prettyprint(out, indent+1);
  dims->prettyprint(out, indent+1);
}

// NOTE: Can this be merged with trans somehow?
void arrayTy::addOps(coenv &e, record *r)
{
  types::ty *t=trans(e, true);

  // Only add ops if it is an array (and not, say, an error)
  if (t->kind == types::ty_array) {
    types::array *at=dynamic_cast<types::array *>(t);
    assert(at);
    e.e.addArrayOps(at);
    if (r)
      r->e.addArrayOps(at);
  }
}
  
types::ty *arrayTy::trans(coenv &e, bool tacit)
{
  types::ty *ct = cell->trans(e, tacit);
  assert(ct);

  // Don't make an array of errors.
  if (ct->kind == types::ty_error)
    return ct;

  types::array *t = dims->truetype(ct);
  assert(t);
  
  return t;
}

tyEntryTy::tyEntryTy(position pos, types::ty *t)
  : ty(pos), ent(new trans::tyEntry(t, 0, 0, position()))
{
}

void tyEntryTy::prettyprint(ostream &out, Int indent)
{
  prettyindent(out,indent);
  out << "tyEntryTy: " << *(ent->t) << "\n";
}

types::ty *tyEntryTy::trans(coenv &, bool) {
  return ent->t;
}


vm::lambda *runnable::transAsCodelet(coenv &e)
{
  coder c=e.c.newCodelet(getPos());
  coenv ce(c, e.e);
  markTrans(ce);
  return c.close();
}


void block::prettystms(ostream &out, Int indent)
{
  for (list<runnable *>::iterator p = stms.begin(); p != stms.end(); ++p)
    (*p)->prettyprint(out, indent);
}

void block::prettyprint(ostream &out, Int indent)
{
  prettyname(out,"block",indent);
  prettystms(out, indent+1);
}

void block::trans(coenv &e)
{
  if (scope) e.e.beginScope();
  for (list<runnable *>::iterator p = stms.begin(); p != stms.end(); ++p) {
    (*p)->markTrans(e);
  }
  if (scope) e.e.endScope();
}

void block::transAsField(coenv &e, record *r)
{
  if (scope) e.e.beginScope();
  for (list<runnable *>::iterator p = stms.begin(); p != stms.end(); ++p) {
    (*p)->markTransAsField(e, r);
  }
  if (scope) e.e.endScope();
}

void block::transAsRecordBody(coenv &e, record *r)
{
  transAsField(e, r);
  e.c.closeRecord();
}

record *block::transAsFile(genv& ge, symbol id)
{
  // Create the new module.
  record *r = new record(id, new frame(id,0,0));

  // Create coder and environment to translate the module.
  // File-level modules have dynamic fields by default.
  coder c(getPos(), r, 0);
  env e(ge);
  coenv ce(c, e);

  // Translate the abstract syntax.
  if (settings::getSetting<bool>("autoplain")) {
    autoplainRunnable()->transAsField(ce, r);
  }
  transAsRecordBody(ce, r);
  em.sync();
  
  return r;
}

bool block::returns() {
  // Search for a returning runnable, starting at the end for efficiency.
  for (list<runnable *>::reverse_iterator p=stms.rbegin();
       p != stms.rend();
       ++p)
    if ((*p)->returns())
      return true;
  return false;
}

vardec *block::asVardec()
{
  vardec *var = 0;
  for (list<runnable *>::iterator p=stms.begin();
       p != stms.end();
       ++p)
  {
    vardec *v = dynamic_cast<vardec *>(*p);
    if (v) {
      if (var)
        // Multiple vardecs.
        return 0;
      var = v;
    }
    else if (!dynamic_cast<emptyStm *>(*p))
      // Failure due to another runnable in the block.
      return 0;
  }

  return var;
}
  

void dec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "dec", indent);
}


void modifierList::prettyprint(ostream &out, Int indent)
{
  prettyindent(out,indent);
  out << "modifierList (";
  
  for (list<modifier>::iterator p = mods.begin(); p != mods.end(); ++p) {
    if (p != mods.begin())
      out << ", ";
    switch (*p) {
      case EXPLICIT_STATIC:
        out << "static";
        break;
#if 0   
      case EXPLICIT_DYNAMIC:
        out << "dynamic";
        break;
#endif  
      default:
        out << "invalid code";
    }
  }
  
  for (list<permission>::iterator p = perms.begin(); p != perms.end(); ++p) {
    if (p != perms.begin() || !mods.empty())
      out << ", ";
    switch (*p) {
      case PUBLIC:
        out << "public";
        break;
      case PRIVATE:
        out << "private";
        break;
      default:
        out << "invalid code";
    }
  }

  out << ")\n";
}

bool modifierList::staticSet()
{
  return !mods.empty();
}

modifier modifierList::getModifier()
{
  if (mods.size() > 1) {
    em.error(getPos());
    em << "too many modifiers";
  }

  assert(staticSet());
  return mods.front();
}

permission modifierList::getPermission()
{
  if (perms.size() > 1) {
    em.error(getPos());
    em << "too many modifiers";
  }

  return perms.empty() ? DEFAULT_PERM : perms.front();
}


void modifiedRunnable::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "modifierRunnable",indent);

  mods->prettyprint(out, indent+1);
  body->prettyprint(out, indent+1);
}

void modifiedRunnable::transAsField(coenv &e, record *r)
{
  if (mods->staticSet()) {
    if (e.c.isTopLevel()) {
      em.warning(getPos());
      em << "static modifier is meaningless at top level";
    }
    e.c.pushModifier(mods->getModifier());
  }

  permission p = mods->getPermission();
#if 0 // This is innocuous 
  if (p != DEFAULT_PERM && (!r || !body->allowPermissions())) {
    em.warning(pos);
    em << "permission modifier is meaningless";
  }
#endif  
  e.c.setPermission(p);

  body->transAsField(e,r);

  e.c.clearPermission();
  if (mods->staticSet())
    e.c.popModifier();
}


void decidstart::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "decidstart '" << id << "'\n";

  if (dims)
    dims->prettyprint(out, indent+1);
}

types::ty *decidstart::getType(types::ty *base, coenv &, bool)
{
  return dims ? dims->truetype(base) : base;
}

trans::tyEntry *decidstart::getTyEntry(trans::tyEntry *base, coenv &e,
                                       record *where)
{
  return dims ? new trans::tyEntry(getType(base->t,e,false), 0,
                                   where, getPos()) :
    base;
}

void decidstart::addOps(types::ty *base, coenv &e, record *r)
{
  if (dims) {
    e.e.addArrayOps(dims->truetype(base));
    if (r)
      r->e.addArrayOps(dims->truetype(base));
  }
}


void fundecidstart::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "fundecidstart '" << id << "'\n";

  if (dims)
    dims->prettyprint(out, indent+1);
  if (params)
    params->prettyprint(out, indent+1);
}

types::ty *fundecidstart::getType(types::ty *base, coenv &e, bool tacit)
{
  types::ty *result = decidstart::getType(base, e, tacit);

  if (params) {
    return params->getType(result, e, true, tacit);
  }
  else {
    types::ty *t = new function(base);
    return t;
  }
}

trans::tyEntry *fundecidstart::getTyEntry(trans::tyEntry *base, coenv &e,
                                          record *where)
{
  return new trans::tyEntry(getType(base->t,e,false), 0, where, getPos());
}

void fundecidstart::addOps(types::ty *base, coenv &e, record *r)
{
  decidstart::addOps(base, e, r);

  params->addOps(e, r);

  types::function *ft=dynamic_cast<types::function *>(getType(base, e, true));
  assert(ft);

  e.e.addFunctionOps(ft);
  if (r)
    r->e.addFunctionOps(ft);
}


void decid::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "decid",indent);

  start->prettyprint(out, indent+1);
  if (init)
    init->prettyprint(out, indent+1);
}


varEntry *makeVarEntryWhere(coenv &e, record *r, types::ty *t,
                            record *where, position pos)
{
  access *a = r ? r->allocField(e.c.isStatic()) :
    e.c.allocLocal();

  return r ? new varEntry(t, a, e.c.getPermission(), r, where, pos) :
    new varEntry(t, a, where, pos);
}

varEntry *makeVarEntry(position pos, coenv &e, record *r, types::ty *t) {
  return makeVarEntryWhere(e, r, t, r, pos);
}


// Defined in constructor.cc.
bool definesImplicitConstructor(coenv &e, record *r, varEntry *v, symbol id);
void addConstructorFromInitializer(position pos, coenv &e, record *r,
                                   varEntry *init);

void addVar(coenv &e, record *r, varEntry *v, symbol id)
{
  // Test for 'operator init' definitions that implicitly define constructors:
  if (definesImplicitConstructor(e, r, v, id))
    addConstructorFromInitializer(position(), e, r, v);

  // Add to the record so it can be accessed when qualified; add to the
  // environment so it can be accessed unqualified in the scope of the
  // record definition.
  if (r)
    r->e.addVar(id, v);
  e.e.addVar(id, v);
}

void initializeVar(position pos, coenv &e, varEntry *v, varinit *init)
{
  types::ty *t=v->getType();

  if (init)
    init->transToType(e, t);
  else {
    definit d(pos);
    d.transToType(e, t);
  }
  
  v->getLocation()->encode(WRITE, pos, e.c);
  e.c.encodePop();
}

types::ty *inferType(position pos, coenv &e, varinit *init)
{
  if (!init) {
    em.error(pos);
    em << "inferred variable declaration without initializer";
    return primError();
  }

  exp *base = dynamic_cast<exp *>(init);
  if (base) {
    types::ty *t = base->cgetType(e);
    if (t->kind != ty_overloaded)
      return t;
  }

  em.error(pos);
  em << "could not infer type of initializer";
  return primError();
}

void createVar(position pos, coenv &e, record *r,
               symbol id, types::ty *t, varinit *init)
{
  // I'm not sure how to handle inferred types in these cases.
  assert(t->kind != types::ty_inferred);

  varEntry *v=makeVarEntry(pos, e, r, t);
  addVar(e, r, v, id);
  initializeVar(pos, e, v, init);
}

void createVarOutOfOrder(position pos, coenv &e, record *r,
                         symbol id, types::ty *t, varinit *init)
{
  /* For declarations such as "var x = 5;", infer the type from the
   * initializer.
   */
  if (t->kind == types::ty_inferred)
    t = inferType(pos, e, init);

  varEntry *v=makeVarEntry(pos, e, r, t);
  initializeVar(pos, e, v, init);
  addVar(e, r, v, id);
}

void addTypeWithPermission(coenv &e, record *r, tyEntry *base, symbol id)
{
  // Only bother encoding permissions for private types.
  tyEntry *ent = (r && e.c.getPermission()==PRIVATE) ?
    new trans::tyEntry(base, PRIVATE, r) :
    base;

  if (r)
    r->e.addType(id, ent);
  e.e.addType(id, ent);
}


void decid::transAsField(coenv &e, record *r, types::ty *base)
{
  types::ty *t = start->getType(base, e);
  assert(t);
  if (t->kind == ty_void) {
    em.error(getPos());
    em << "cannot declare variable of type void";
  }

  start->addOps(base, e, r);

  createVarOutOfOrder(getPos(), e, r, start->getName(), t, init);
}

void decid::transAsTypedefField(coenv &e, trans::tyEntry *base, record *r)
{
  trans::tyEntry *ent = start->getTyEntry(base, e, r);
  assert(ent && ent->t);

  if (init) {
    em.error(getPos());
    em << "type definition cannot have initializer";
  }
   
  start->addOps(base->t, e, r);

  addTypeWithPermission(e, r, ent, start->getName());
}


void decidlist::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "decidlist",indent);

  for (list<decid *>::iterator p = decs.begin(); p != decs.end(); ++p)
    (*p)->prettyprint(out, indent+1);
}

void decidlist::transAsField(coenv &e, record *r, types::ty *base)
{
  for (list<decid *>::iterator p = decs.begin(); p != decs.end(); ++p)
    (*p)->transAsField(e, r, base);
}

void decidlist::transAsTypedefField(coenv &e, trans::tyEntry *base, record *r)
{
  for (list<decid *>::iterator p = decs.begin(); p != decs.end(); ++p)
    (*p)->transAsTypedefField(e, base, r);
}


void vardec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "vardec",indent);

  base->prettyprint(out, indent+1);
  decs->prettyprint(out, indent+1);
}

void vardec::transAsTypedefField(coenv &e, record *r)
{
  base->addOps(e, r);
  decs->transAsTypedefField(e, base->transAsTyEntry(e, r), r);
}

symbol vardec::singleName()
{
  decid *did = decs->singleEntry();
  if (!did)
    return symbol::nullsym;
  return did->getStart()->getName();
}

types::ty *vardec::singleGetType(coenv &e)
{
  decid *did = decs->singleEntry();
  if (!did)
    return 0;
  return did->getStart()->getType(base->trans(e), e);
}


// Helper class for imports.  This essentially evaluates to the run::loadModule
// function.  However, that function returns different types of records
// depending on the filename given to it, so we cannot add it to the
// environment.  Instead, we explicitly tell it what types::record it is
// returning for each use.
class loadModuleExp : public exp {
  record *imp;
  function *ft;

public:
  loadModuleExp(position pos, record *imp)
    : exp(pos), imp(imp), ft(new function(imp,primString())) {}

  void prettyprint(ostream &out, Int indent) {
    prettyname(out, "loadModuleExp", indent);
  }

  types::ty *trans(coenv &) {
    em.compiler(getPos());
    em << "trans called for loadModuleExp";
    return primError();
  }

  void transCall(coenv &e, types::ty *t) {
    assert(equivalent(t, ft));
    e.c.encode(inst::builtin, run::loadModule);
  }

  types::ty *getType(coenv &) {
    return ft;
  }

  exp *evaluate(coenv &, types::ty *) {
    // Don't alias.
    return this;
  }
};

// Creates a local variable to hold the import and translate the accessing of
// the import, but doesn't add the import to the environment.
varEntry *accessModule(position pos, coenv &e, record *r, symbol id)
{
  record *imp=e.e.getModule(id, (string)id);
  if (!imp) {
    em.error(pos);
    em << "could not load module '" << id << "'";
    em.sync();
    return 0;
  }
  else {
    // Create a varinit that evaluates to the module.
    // This is effectively the expression "loadModule(filename)".
    callExp init(pos, new loadModuleExp(pos, imp),
                 new stringExp(pos, (string)id));

    // The varEntry should have whereDefined()==0 as it is not defined inside
    // the record r.
    varEntry *v=makeVarEntryWhere(e, r, imp, 0, pos);
    initializeVar(pos, e, v, &init);
    return v;
  }
}


void idpair::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "idpair (" << "'" << src << "' as " << dest << ")\n";
}

void idpair::transAsAccess(coenv &e, record *r)
{
  checkValidity();

  varEntry *v=accessModule(getPos(), e, r, src);
  if (v)
    addVar(e, r, v, dest);
}

void idpair::transAsUnravel(coenv &e, record *r,
                            protoenv &source, varEntry *qualifier)
{
  checkValidity();

  if (r)
    r->e.add(src, dest, source, qualifier, e.c);
  if (!e.e.add(src, dest, source, qualifier, e.c)) {
    em.error(getPos());
    em << "no matching types or fields of name '" << src << "'";
  }
}


void idpairlist::prettyprint(ostream &out, Int indent)
{
  for (list<idpair *>::iterator p=base.begin();
       p != base.end();
       ++p)
    (*p)->prettyprint(out, indent);
}

void idpairlist::transAsAccess(coenv &e, record *r)
{
  for (list<idpair *>::iterator p=base.begin();
       p != base.end();
       ++p)
    (*p)->transAsAccess(e,r);
}

void idpairlist::transAsUnravel(coenv &e, record *r,
                                protoenv &source, varEntry *qualifier)
{
  for (list<idpair *>::iterator p=base.begin();
       p != base.end();
       ++p)
    (*p)->transAsUnravel(e,r,source,qualifier);
}

idpairlist * const WILDCARD = 0;

void accessdec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "accessdec", indent);
  base->prettyprint(out, indent+1);
}


void fromdec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "fromdec", indent);
  fields->prettyprint(out, indent+1);
}

void fromdec::transAsField(coenv &e, record *r)
{
  qualifier q=getQualifier(e,r);
  if (q.t) {
    if (fields==WILDCARD) {
      if (r)
        r->e.add(q.t->e, q.v, e.c);
      e.e.add(q.t->e, q.v, e.c);
    }
    else
      fields->transAsUnravel(e, r, q.t->e, q.v);
  }
}


void unraveldec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "unraveldec", indent);
  id->prettyprint(out, indent+1);
  idpairlist *f=this->fields;
  if(f) f->prettyprint(out, indent+1);
}

fromdec::qualifier unraveldec::getQualifier(coenv &e, record *)
{
  // getType is where errors in the qualifier are reported.
  record *qt=dynamic_cast<record *>(id->getType(e, false));
  if (!qt) {
    em.error(getPos());
    em << "qualifier is not a record";
  }

  return qualifier(qt,id->getVarEntry(e));
}

void fromaccessdec::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "fromaccessdec '" << id << "'\n";
  idpairlist *f=this->fields;
  if(f) f->prettyprint(out, indent+1);
}

fromdec::qualifier fromaccessdec::getQualifier(coenv &e, record *r)
{
  varEntry *v=accessModule(getPos(), e, r, id);
  if (v) {
    record *qt=dynamic_cast<record *>(v->getType());
    if (!qt) {
      em.compiler(getPos());
      em << "qualifier is not a record";
    }
    return qualifier(qt, v);
  }
  else
    return qualifier(0,0);
}

void importdec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "importdec", indent);
  base.prettyprint(out, indent+1);
}

void includedec::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "includedec ('" << filename << "')\n";
}

void includedec::loadFailed(coenv &)
{
  em.warning(getPos());
  em << "could not parse file of name '" << filename << "'";
  em.sync();
}

void includedec::transAsField(coenv &e, record *r)
{
  file *ast = parser::parseFile(filename,"Including");
  em.sync();

  // The runnables will be translated, one at a time, without any additional
  // scoping.
  ast->transAsField(e, r);
}


void typedec::prettyprint(ostream &out, Int indent)
{
  prettyname(out, "typedec",indent);

  body->prettyprint(out, indent+1);
}


void recorddec::prettyprint(ostream &out, Int indent)
{
  prettyindent(out, indent);
  out << "structdec '" << id << "'\n";

  body->prettyprint(out, indent+1);
}

void recorddec::transRecordInitializer(coenv &e, record *parent)
{
  position here=getPos();

  // This is equivalent to the code
  //   A operator init() { return new A; }
  // where A is the name of the record.
  formals formals(here);
  simpleName recordName(here, id);
  nameTy result(here, &recordName);
  newRecordExp exp(here, &result);
  returnStm stm(here, &exp);
  fundec init(here, &result, symbol::opTrans("init"), &formals, &stm);

  init.transAsField(e, parent);
}

void recorddec::addPostRecordEnvironment(coenv &e, record *r, record *parent) {
  if (parent)
    parent->e.add(r->postdefenv, 0, e.c);
  e.e.add(r->postdefenv, 0, e.c);
}

void recorddec::transAsField(coenv &e, record *parent)
{
  record *r = parent ? parent->newRecord(id, e.c.isStatic()) :
    e.c.newRecord(id);
                     
  addTypeWithPermission(e, parent, new trans::tyEntry(r,0,parent,getPos()), id);
  e.e.addRecordOps(r);
  if (parent)
    parent->e.addRecordOps(r);

  // Start translating the initializer.
  coder c=e.c.newRecordInit(getPos(), r);
  coenv re(c,e.e);
  
  body->transAsRecordBody(re, r);

  // After the record is translated, add a default initializer so that a
  // variable of the type of the record is initialized to a new instance by
  // default.
  transRecordInitializer(e, parent);

  // Add types and variables defined during the record that should be added to
  // the enclosing environment.  These are the implicit constructors defined by
  // "operator init".
  addPostRecordEnvironment(e, r, parent);
}  

runnable *autoplainRunnable() {
  // Abstract syntax for the code:
  //   private import plain;
  position pos=position();
  static importdec ap(pos, new idpair(pos, symbol::trans("plain")));
  static modifiedRunnable mr(pos, trans::PRIVATE, &ap);

  return &mr;
}

} // namespace absyntax