/******************************************
* Return elem that evaluates to the static frame pointer for function fd.
* If fd is a member function, the returned expression will compute the value
* of fd's 'this' variable.
* This routine is critical for implementing nested functions.
*/
elem *getEthis(Loc loc, IRState *irs, Dsymbol *fd)
{
elem *ethis;
FuncDeclaration *thisfd = irs->getFunc();
Dsymbol *fdparent = fd->toParent2();
Dsymbol *fdp = fdparent;
/* These two are compiler generated functions for the in and out contracts,
* and are called from an overriding function, not just the one they're
* nested inside, so this hack is so they'll pass
*/
if (fdparent != thisfd && (fd->ident == Id::require || fd->ident == Id::ensure))
{
FuncDeclaration *fdthis = thisfd;
for (size_t i = 0; ; )
{
if (i == fdthis->foverrides.dim)
{
if (i == 0)
break;
fdthis = fdthis->foverrides[0];
i = 0;
continue;
}
if (fdthis->foverrides[i] == fdp)
{
fdparent = thisfd;
break;
}
i++;
}
}
//printf("[%s] getEthis(thisfd = '%s', fd = '%s', fdparent = '%s')\n", loc.toChars(), thisfd->toPrettyChars(), fd->toPrettyChars(), fdparent->toPrettyChars());
if (fdparent == thisfd)
{
/* Going down one nesting level, i.e. we're calling
* a nested function from its enclosing function.
*/
if (irs->sclosure && !(fd->ident == Id::require || fd->ident == Id::ensure))
{
ethis = el_var(irs->sclosure);
}
else if (irs->sthis)
{
// We have a 'this' pointer for the current function
/* If no variables in the current function's frame are
* referenced by nested functions, then we can 'skip'
* adding this frame into the linked list of stack
* frames.
*/
if (thisfd->hasNestedFrameRefs())
{
/* Local variables are referenced, can't skip.
* Address of 'sthis' gives the 'this' for the nested
* function
*/
ethis = el_ptr(irs->sthis);
}
else
{
ethis = el_var(irs->sthis);
}
}
else
{
/* No 'this' pointer for current function,
*/
if (thisfd->hasNestedFrameRefs())
{
/* OPframeptr is an operator that gets the frame pointer
* for the current function, i.e. for the x86 it gets
* the value of EBP
*/
ethis = el_long(TYnptr, 0);
ethis->Eoper = OPframeptr;
}
else
{
/* Use NULL if no references to the current function's frame
*/
ethis = el_long(TYnptr, 0);
}
}
}
else
{
if (!irs->sthis) // if no frame pointer for this function
{
fd->error(loc, "is a nested function and cannot be accessed from %s", irs->getFunc()->toPrettyChars());
return el_long(TYnptr, 0); // error recovery
}
/* Go up a nesting level, i.e. we need to find the 'this'
* of an enclosing function.
* Our 'enclosing function' may also be an inner class.
*/
ethis = el_var(irs->sthis);
Dsymbol *s = thisfd;
while (fd != s)
{
FuncDeclaration *fdp = s->toParent2()->isFuncDeclaration();
//printf("\ts = '%s'\n", s->toChars());
thisfd = s->isFuncDeclaration();
if (thisfd)
{
/* Enclosing function is a function.
*/
// Error should have been caught by front end
assert(thisfd->isNested() || thisfd->vthis);
}
else
{
/* Enclosed by an aggregate. That means the current
* function must be a member function of that aggregate.
*/
AggregateDeclaration *ad = s->isAggregateDeclaration();
if (!ad)
{
Lnoframe:
irs->getFunc()->error(loc, "cannot get frame pointer to %s", fd->toPrettyChars());
return el_long(TYnptr, 0); // error recovery
}
ClassDeclaration *cd = ad->isClassDeclaration();
ClassDeclaration *cdx = fd->isClassDeclaration();
if (cd && cdx && cdx->isBaseOf(cd, NULL))
break;
StructDeclaration *sd = ad->isStructDeclaration();
if (fd == sd)
break;
if (!ad->isNested() || !ad->vthis)
goto Lnoframe;
ethis = el_bin(OPadd, TYnptr, ethis, el_long(TYsize_t, ad->vthis->offset));
ethis = el_una(OPind, TYnptr, ethis);
}
if (fdparent == s->toParent2())
break;
/* Remember that frames for functions that have no
* nested references are skipped in the linked list
* of frames.
*/
if (fdp && fdp->hasNestedFrameRefs())
ethis = el_una(OPind, TYnptr, ethis);
s = s->toParent2();
assert(s);
}
}
#if 0
printf("ethis:\n");
elem_print(ethis);
printf("\n");
#endif
return ethis;
}
void Declaration::checkModify(Loc loc, Scope *sc, Type *t)
{
if (sc->incontract && isParameter())
error(loc, "cannot modify parameter '%s' in contract", toChars());
if (sc->incontract && isResult())
error(loc, "cannot modify result '%s' in contract", toChars());
if (isCtorinit() && !t->isMutable())
{ // It's only modifiable if inside the right constructor
Dsymbol *s = sc->func;
while (1)
{
FuncDeclaration *fd = NULL;
if (s)
fd = s->isFuncDeclaration();
if (fd &&
((fd->isCtorDeclaration() && storage_class & STCfield) ||
(fd->isStaticCtorDeclaration() && !(storage_class & STCfield))) &&
fd->toParent() == toParent()
)
{
VarDeclaration *v = isVarDeclaration();
assert(v);
v->ctorinit = 1;
//printf("setting ctorinit\n");
}
else
{
if (s)
{ s = s->toParent2();
continue;
}
else
{
const char *p = isStatic() ? "static " : "";
error(loc, "can only initialize %sconst %s inside %sconstructor",
p, toChars(), p);
}
}
break;
}
}
else
{
VarDeclaration *v = isVarDeclaration();
if (v && v->canassign == 0)
{
const char *p = NULL;
if (isConst())
p = "const";
else if (isImmutable())
p = "immutable";
else if (storage_class & STCmanifest)
p = "enum";
else if (!t->isAssignable())
p = "struct with immutable members";
if (p)
{ error(loc, "cannot modify %s", p);
}
}
}
}
void DtoCreateNestedContext(FuncDeclaration* fd) {
Logger::println("DtoCreateNestedContext for %s", fd->toChars());
LOG_SCOPE
DtoCreateNestedContextType(fd);
if (nestedCtx == NCArray) {
// construct nested variables array
if (!fd->nestedVars.empty())
{
Logger::println("has nested frame");
// start with adding all enclosing parent frames until a static parent is reached
int nparelems = 0;
if (!fd->isStatic())
{
Dsymbol* par = fd->toParent2();
while (par)
{
if (FuncDeclaration* parfd = par->isFuncDeclaration())
{
nparelems += parfd->nestedVars.size();
// stop at first static
if (parfd->isStatic())
break;
}
else if (par->isClassDeclaration())
{
// nothing needed
}
else
{
break;
}
par = par->toParent2();
}
}
int nelems = fd->nestedVars.size() + nparelems;
// make array type for nested vars
LLType* nestedVarsTy = LLArrayType::get(getVoidPtrType(), nelems);
// alloca it
// FIXME align ?
LLValue* nestedVars = DtoRawAlloca(nestedVarsTy, 0, ".nested_vars");
IrFunction* irfunction = fd->ir.irFunc;
// copy parent frame into beginning
if (nparelems)
{
LLValue* src = irfunction->nestArg;
if (!src)
{
assert(irfunction->thisArg);
assert(fd->isMember2());
LLValue* thisval = DtoLoad(irfunction->thisArg);
ClassDeclaration* cd = fd->isMember2()->isClassDeclaration();
assert(cd);
assert(cd->vthis);
src = DtoLoad(DtoGEPi(thisval, 0,cd->vthis->ir.irField->index, ".vthis"));
} else {
src = DtoLoad(src);
}
DtoMemCpy(nestedVars, src, DtoConstSize_t(nparelems*PTRSIZE),
getABITypeAlign(getVoidPtrType()));
}
// store in IrFunction
irfunction->nestedVar = nestedVars;
// go through all nested vars and assign indices
int idx = nparelems;
for (std::set<VarDeclaration*>::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i)
{
VarDeclaration* vd = *i;
if (!vd->ir.irLocal)
vd->ir.irLocal = new IrLocal(vd);
if (vd->isParameter())
{
Logger::println("nested param: %s", vd->toChars());
LLValue* gep = DtoGEPi(nestedVars, 0, idx);
LLValue* val = DtoBitCast(vd->ir.irLocal->value, getVoidPtrType());
DtoAlignedStore(val, gep);
}
else
{
Logger::println("nested var: %s", vd->toChars());
}
vd->ir.irLocal->nestedIndex = idx++;
}
}
}
else if (nestedCtx == NCHybrid) {
// construct nested variables array
if (!fd->nestedVars.empty())
{
IrFunction* irfunction = fd->ir.irFunc;
unsigned depth = irfunction->depth;
LLStructType *frameType = irfunction->frameType;
// Create frame for current function and append to frames list
// FIXME: alignment ?
LLValue* frame = 0;
#if DMDV2
if (fd->needsClosure())
frame = DtoGcMalloc(frameType, ".frame");
else
#endif
frame = DtoRawAlloca(frameType, 0, ".frame");
// copy parent frames into beginning
if (depth != 0) {
LLValue* src = irfunction->nestArg;
if (!src) {
assert(irfunction->thisArg);
assert(fd->isMember2());
LLValue* thisval = DtoLoad(irfunction->thisArg);
#if DMDV2
AggregateDeclaration* cd = fd->isMember2();
#else
ClassDeclaration* cd = fd->isMember2()->isClassDeclaration();
#endif
assert(cd);
assert(cd->vthis);
Logger::println("Indexing to 'this'");
#if DMDV2
if (cd->isStructDeclaration())
src = DtoExtractValue(thisval, cd->vthis->ir.irField->index, ".vthis");
else
#endif
src = DtoLoad(DtoGEPi(thisval, 0, cd->vthis->ir.irField->index, ".vthis"));
} else {
src = DtoLoad(src);
}
if (depth > 1) {
src = DtoBitCast(src, getVoidPtrType());
LLValue* dst = DtoBitCast(frame, getVoidPtrType());
DtoMemCpy(dst, src, DtoConstSize_t((depth-1) * PTRSIZE),
getABITypeAlign(getVoidPtrType()));
}
// Copy nestArg into framelist; the outer frame is not in the list of pointers
src = DtoBitCast(src, frameType->getContainedType(depth-1));
LLValue* gep = DtoGEPi(frame, 0, depth-1);
DtoAlignedStore(src, gep);
}
// store context in IrFunction
irfunction->nestedVar = frame;
// go through all nested vars and assign addresses where possible.
for (std::set<VarDeclaration*>::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i)
{
VarDeclaration* vd = *i;
LLValue* gep = DtoGEPi(frame, 0, vd->ir.irLocal->nestedIndex, vd->toChars());
if (vd->isParameter()) {
Logger::println("nested param: %s", vd->toChars());
LOG_SCOPE
LLValue* value = vd->ir.irLocal->value;
if (llvm::isa<llvm::AllocaInst>(llvm::GetUnderlyingObject(value))) {
Logger::println("Copying to nested frame");
// The parameter value is an alloca'd stack slot.
// Copy to the nesting frame and leave the alloca for
// the optimizers to clean up.
assert(!vd->ir.irLocal->byref);
DtoStore(DtoLoad(value), gep);
gep->takeName(value);
vd->ir.irLocal->value = gep;
} else {
Logger::println("Adding pointer to nested frame");
// The parameter value is something else, such as a
// passed-in pointer (for 'ref' or 'out' parameters) or
// a pointer arg with byval attribute.
// Store the address into the frame.
assert(vd->ir.irLocal->byref);
storeVariable(vd, gep);
}
} else if (vd->isRef() || vd->isOut()) {
// This slot is initialized in DtoNestedInit, to handle things like byref foreach variables
// which move around in memory.
assert(vd->ir.irLocal->byref);
} else {
Logger::println("nested var: %s", vd->toChars());
if (vd->ir.irLocal->value)
Logger::cout() << "Pre-existing value: " << *vd->ir.irLocal->value << '\n';
assert(!vd->ir.irLocal->value);
vd->ir.irLocal->value = gep;
assert(!vd->ir.irLocal->byref);
}
if (global.params.symdebug) {
LLSmallVector<LLValue*, 2> addr;
dwarfOpOffset(addr, frameType, vd->ir.irLocal->nestedIndex);
DtoDwarfLocalVariable(frame, vd, addr);
}
}
} else if (FuncDeclaration* parFunc = getParentFunc(fd, true)) {
// Propagate context arg properties if the context arg is passed on unmodified.
DtoDeclareFunction(parFunc);
fd->ir.irFunc->frameType = parFunc->ir.irFunc->frameType;
fd->ir.irFunc->depth = parFunc->ir.irFunc->depth;
}
}
else {
assert(0 && "Not implemented yet");
}
}
