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/* Compiler implementation of the D programming language
* Copyright (C) 1999-2020 by The D Language Foundation, All Rights Reserved
* written by Walter Bright
* http://www.digitalmars.com
* Distributed under the Boost Software License, Version 1.0.
* http://www.boost.org/LICENSE_1_0.txt
* https://github.com/D-Programming-Language/dmd/blob/master/src/access.c
*/
#include "root/dsystem.h"
#include "root/root.h"
#include "root/rmem.h"
#include "errors.h"
#include "enum.h"
#include "aggregate.h"
#include "init.h"
#include "attrib.h"
#include "scope.h"
#include "id.h"
#include "mtype.h"
#include "declaration.h"
#include "aggregate.h"
#include "expression.h"
#include "module.h"
#include "template.h"
/* Code to do access checks
*/
bool hasPackageAccess(Scope *sc, Dsymbol *s);
bool hasPackageAccess(Module *mod, Dsymbol *s);
bool hasPrivateAccess(AggregateDeclaration *ad, Dsymbol *smember);
bool isFriendOf(AggregateDeclaration *ad, AggregateDeclaration *cd);
static Dsymbol *mostVisibleOverload(Dsymbol *s);
/****************************************
* Return Prot access for Dsymbol smember in this declaration.
*/
Prot getAccess(AggregateDeclaration *ad, Dsymbol *smember)
{
Prot access_ret = Prot(Prot::none);
assert(ad->isStructDeclaration() || ad->isClassDeclaration());
if (smember->toParent() == ad)
{
access_ret = smember->prot();
}
else if (smember->isDeclaration()->isStatic())
{
access_ret = smember->prot();
}
if (ClassDeclaration *cd = ad->isClassDeclaration())
{
for (size_t i = 0; i < cd->baseclasses->length; i++)
{
BaseClass *b = (*cd->baseclasses)[i];
Prot access = getAccess(b->sym, smember);
switch (access.kind)
{
case Prot::none:
break;
case Prot::private_:
access_ret = Prot(Prot::none); // private members of base class not accessible
break;
case Prot::package_:
case Prot::protected_:
case Prot::public_:
case Prot::export_:
// If access is to be tightened
if (Prot::public_ < access.kind)
access = Prot(Prot::public_);
// Pick path with loosest access
if (access_ret.isMoreRestrictiveThan(access))
access_ret = access;
break;
default:
assert(0);
}
}
}
return access_ret;
}
/********************************************************
* Helper function for checkAccess()
* Returns:
* false is not accessible
* true is accessible
*/
static bool isAccessible(
Dsymbol *smember,
Dsymbol *sfunc,
AggregateDeclaration *dthis,
AggregateDeclaration *cdscope)
{
assert(dthis);
if (hasPrivateAccess(dthis, sfunc) ||
isFriendOf(dthis, cdscope))
{
if (smember->toParent() == dthis)
return true;
if (ClassDeclaration *cdthis = dthis->isClassDeclaration())
{
for (size_t i = 0; i < cdthis->baseclasses->length; i++)
{
BaseClass *b = (*cdthis->baseclasses)[i];
Prot access = getAccess(b->sym, smember);
if (access.kind >= Prot::protected_ ||
isAccessible(smember, sfunc, b->sym, cdscope))
{
return true;
}
}
}
}
else
{
if (smember->toParent() != dthis)
{
if (ClassDeclaration *cdthis = dthis->isClassDeclaration())
{
for (size_t i = 0; i < cdthis->baseclasses->length; i++)
{
BaseClass *b = (*cdthis->baseclasses)[i];
if (isAccessible(smember, sfunc, b->sym, cdscope))
return true;
}
}
}
}
return false;
}
/*******************************
* Do access check for member of this class, this class being the
* type of the 'this' pointer used to access smember.
* Returns true if the member is not accessible.
*/
bool checkAccess(AggregateDeclaration *ad, Loc loc, Scope *sc, Dsymbol *smember)
{
FuncDeclaration *f = sc->func;
AggregateDeclaration *cdscope = sc->getStructClassScope();
Dsymbol *smemberparent = smember->toParent();
if (!smemberparent || !smemberparent->isAggregateDeclaration())
{
return false; // then it is accessible
}
// BUG: should enable this check
//assert(smember->parent->isBaseOf(this, NULL));
bool result;
Prot access;
if (smemberparent == ad)
{
access = smember->prot();
result = access.kind >= Prot::public_ ||
hasPrivateAccess(ad, f) ||
isFriendOf(ad, cdscope) ||
(access.kind == Prot::package_ && hasPackageAccess(sc, smember)) ||
ad->getAccessModule() == sc->_module;
}
else if ((access = getAccess(ad, smember)).kind >= Prot::public_)
{
result = true;
}
else if (access.kind == Prot::package_ && hasPackageAccess(sc, ad))
{
result = true;
}
else
{
result = isAccessible(smember, f, ad, cdscope);
}
if (!result)
{
ad->error(loc, "member %s is not accessible", smember->toChars());
//printf("smember = %s %s, prot = %d, semanticRun = %d\n",
// smember->kind(), smember->toPrettyChars(), smember->prot(), smember->semanticRun);
return true;
}
return false;
}
/****************************************
* Determine if this is the same or friend of cd.
*/
bool isFriendOf(AggregateDeclaration *ad, AggregateDeclaration *cd)
{
if (ad == cd)
return true;
// Friends if both are in the same module
//if (toParent() == cd->toParent())
if (cd && ad->getAccessModule() == cd->getAccessModule())
{
return true;
}
return false;
}
/****************************************
* Determine if scope sc has package level access to s.
*/
bool hasPackageAccess(Scope *sc, Dsymbol *s)
{
return hasPackageAccess(sc->_module, s);
}
bool hasPackageAccess(Module *mod, Dsymbol *s)
{
Package *pkg = NULL;
if (s->prot().pkg)
pkg = s->prot().pkg;
else
{
// no explicit package for protection, inferring most qualified one
for (; s; s = s->parent)
{
if (Module *m = s->isModule())
{
DsymbolTable *dst = Package::resolve(m->md ? m->md->packages : NULL, NULL, NULL);
assert(dst);
Dsymbol *s2 = dst->lookup(m->ident);
assert(s2);
Package *p = s2->isPackage();
if (p && p->isPackageMod())
{
pkg = p;
break;
}
}
else if ((pkg = s->isPackage()) != NULL)
break;
}
}
if (pkg)
{
if (pkg == mod->parent)
{
return true;
}
if (pkg->isPackageMod() == mod)
{
return true;
}
Dsymbol* ancestor = mod->parent;
for (; ancestor; ancestor = ancestor->parent)
{
if (ancestor == pkg)
{
return true;
}
}
}
return false;
}
/****************************************
* Determine if scope sc has protected level access to cd.
*/
bool hasProtectedAccess(Scope *sc, Dsymbol *s)
{
if (ClassDeclaration *cd = s->isClassMember()) // also includes interfaces
{
for (Scope *scx = sc; scx; scx = scx->enclosing)
{
if (!scx->scopesym)
continue;
ClassDeclaration *cd2 = scx->scopesym->isClassDeclaration();
if (cd2 && cd->isBaseOf(cd2, NULL))
return true;
}
}
return sc->_module == s->getAccessModule();
}
/**********************************
* Determine if smember has access to private members of this declaration.
*/
bool hasPrivateAccess(AggregateDeclaration *ad, Dsymbol *smember)
{
if (smember)
{
AggregateDeclaration *cd = NULL;
Dsymbol *smemberparent = smember->toParent();
if (smemberparent)
cd = smemberparent->isAggregateDeclaration();
if (ad == cd) // smember is a member of this class
{
return true; // so we get private access
}
// If both are members of the same module, grant access
while (1)
{
Dsymbol *sp = smember->toParent();
if (sp->isFuncDeclaration() && smember->isFuncDeclaration())
smember = sp;
else
break;
}
if (!cd && ad->toParent() == smember->toParent())
{
return true;
}
if (!cd && ad->getAccessModule() == smember->getAccessModule())
{
return true;
}
}
return false;
}
/****************************************
* Check access to d for expression e.d
* Returns true if the declaration is not accessible.
*/
bool checkAccess(Loc loc, Scope *sc, Expression *e, Declaration *d)
{
if (sc->flags & SCOPEnoaccesscheck)
return false;
if (d->isUnitTestDeclaration())
{
// Unittests are always accessible.
return false;
}
if (!e)
{
if ((d->prot().kind == Prot::private_ && d->getAccessModule() != sc->_module) ||
(d->prot().kind == Prot::package_ && !hasPackageAccess(sc, d)))
{
error(loc, "%s %s is not accessible from module %s",
d->kind(), d->toPrettyChars(), sc->_module->toChars());
return true;
}
}
else if (e->type->ty == Tclass)
{
// Do access check
ClassDeclaration *cd = (ClassDeclaration *)(((TypeClass *)e->type)->sym);
if (e->op == TOKsuper)
{
ClassDeclaration *cd2 = sc->func->toParent()->isClassDeclaration();
if (cd2)
cd = cd2;
}
return checkAccess(cd, loc, sc, d);
}
else if (e->type->ty == Tstruct)
{
// Do access check
StructDeclaration *cd = (StructDeclaration *)(((TypeStruct *)e->type)->sym);
return checkAccess(cd, loc, sc, d);
}
return false;
}
/****************************************
* Check access to package/module `p` from scope `sc`.
*
* Params:
* loc = source location for issued error message
* sc = scope from which to access to a fully qualified package name
* p = the package/module to check access for
* Returns: true if the package is not accessible.
*
* Because a global symbol table tree is used for imported packages/modules,
* access to them needs to be checked based on the imports in the scope chain
* (see Bugzilla 313).
*
*/
bool checkAccess(Loc loc, Scope *sc, Package *p)
{
if (sc->_module == p)
return false;
for (; sc; sc = sc->enclosing)
{
if (sc->scopesym && sc->scopesym->isPackageAccessible(p, Prot(Prot::private_)))
return false;
}
const char *name = p->toPrettyChars();
if (p->isPkgMod == PKGmodule || p->isModule())
deprecation(loc, "%s %s is not accessible here, perhaps add 'static import %s;'", p->kind(), name, name);
else
deprecation(loc, "%s %s is not accessible here", p->kind(), name);
return true;
}
/**
* Check whether symbols `s` is visible in `mod`.
*
* Params:
* mod = lookup origin
* s = symbol to check for visibility
* Returns: true if s is visible in mod
*/
bool symbolIsVisible(Module *mod, Dsymbol *s)
{
// should sort overloads by ascending protection instead of iterating here
s = mostVisibleOverload(s);
switch (s->prot().kind)
{
case Prot::undefined:
return true;
case Prot::none:
return false; // no access
case Prot::private_:
return s->getAccessModule() == mod;
case Prot::package_:
return s->getAccessModule() == mod || hasPackageAccess(mod, s);
case Prot::protected_:
return s->getAccessModule() == mod;
case Prot::public_:
case Prot::export_:
return true;
default:
assert(0);
}
return false;
}
/**
* Same as above, but determines the lookup module from symbols `origin`.
*/
bool symbolIsVisible(Dsymbol *origin, Dsymbol *s)
{
return symbolIsVisible(origin->getAccessModule(), s);
}
/**
* Same as above but also checks for protected symbols visible from scope `sc`.
* Used for qualified name lookup.
*
* Params:
* sc = lookup scope
* s = symbol to check for visibility
* Returns: true if s is visible by origin
*/
bool symbolIsVisible(Scope *sc, Dsymbol *s)
{
s = mostVisibleOverload(s);
switch (s->prot().kind)
{
case Prot::undefined:
return true;
case Prot::none:
return false; // no access
case Prot::private_:
return sc->_module == s->getAccessModule();
case Prot::package_:
return sc->_module == s->getAccessModule() || hasPackageAccess(sc->_module, s);
case Prot::protected_:
return hasProtectedAccess(sc, s);
case Prot::public_:
case Prot::export_:
return true;
default:
assert(0);
}
return false;
}
/**
* Use the most visible overload to check visibility. Later perform an access
* check on the resolved overload. This function is similar to overloadApply,
* but doesn't recurse nor resolve aliases because protection/visibility is an
* attribute of the alias not the aliasee.
*/
static Dsymbol *mostVisibleOverload(Dsymbol *s)
{
if (!s->isOverloadable())
return s;
Dsymbol *next = NULL;
Dsymbol *fstart = s;
Dsymbol *mostVisible = s;
for (; s; s = next)
{
// void func() {}
// private void func(int) {}
if (FuncDeclaration *fd = s->isFuncDeclaration())
next = fd->overnext;
// template temp(T) {}
// private template temp(T:int) {}
else if (TemplateDeclaration *td = s->isTemplateDeclaration())
next = td->overnext;
// alias common = mod1.func1;
// alias common = mod2.func2;
else if (FuncAliasDeclaration *fa = s->isFuncAliasDeclaration())
next = fa->overnext;
// alias common = mod1.templ1;
// alias common = mod2.templ2;
else if (OverDeclaration *od = s->isOverDeclaration())
next = od->overnext;
// alias name = sym;
// private void name(int) {}
else if (AliasDeclaration *ad = s->isAliasDeclaration())
{
if (!ad->isOverloadable())
{
//printf("Non overloadable Aliasee in overload list\n");
assert(0);
}
// Yet unresolved aliases store overloads in overnext.
if (ad->semanticRun < PASSsemanticdone)
next = ad->overnext;
else
{
/* This is a bit messy due to the complicated implementation of
* alias. Aliases aren't overloadable themselves, but if their
* Aliasee is overloadable they can be converted to an overloadable
* alias.
*
* This is done by replacing the Aliasee w/ FuncAliasDeclaration
* (for functions) or OverDeclaration (for templates) which are
* simply overloadable aliases w/ weird names.
*
* Usually aliases should not be resolved for visibility checking
* b/c public aliases to private symbols are public. But for the
* overloadable alias situation, the Alias (_ad_) has been moved
* into it's own Aliasee, leaving a shell that we peel away here.
*/
Dsymbol *aliasee = ad->toAlias();
if (aliasee->isFuncAliasDeclaration() || aliasee->isOverDeclaration())
next = aliasee;
else
{
/* A simple alias can be at the end of a function or template overload chain.
* It can't have further overloads b/c it would have been
* converted to an overloadable alias.
*/
if (ad->overnext)
{
//printf("Unresolved overload of alias\n");
assert(0);
}
break;
}
}
// handled by overloadApply for unknown reason
assert(next != ad); // should not alias itself
assert(next != fstart); // should not alias the overload list itself
}
else
break;
if (next && mostVisible->prot().isMoreRestrictiveThan(next->prot()))
mostVisible = next;
}
return mostVisible;
}
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