#include "gen/nested.h" #include "gen/dvalue.h" #include "gen/irstate.h" #include "gen/llvmhelpers.h" #include "gen/logger.h" #include "gen/tollvm.h" #include "gen/functions.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/Support/CommandLine.h" namespace cl = llvm::cl; /// What the context pointer for a nested function looks like enum NestedCtxType { /// Context is void*[] of pointers to variables. /// Variables from higher levels are at the front. NCArray, /// Context is a struct containing variables belonging to the parent function. /// If the parent function itself has a parent function, one of the members is /// a pointer to its context. (linked-list style) // FIXME: implement // TODO: Functions without any variables accessed by nested functions, but // with a parent whose variables are accessed, can use the parent's // context. // NOTE: This is what DMD seems to do. NCStruct, /// Context is a list of pointers to structs of variables, followed by the /// variables of the inner-most function with variables accessed by nested /// functions. The initial pointers point to similar structs for enclosing /// functions. /// Only functions whose variables are accessed by nested functions create /// new frames, others just pass on what got passed in. NCHybrid }; static cl::opt nestedCtx("nested-ctx", cl::desc("How to construct a nested function's context:"), cl::ZeroOrMore, cl::values( clEnumValN(NCArray, "array", "Array of pointers to variables (including multi-level)"), //clEnumValN(NCStruct, "struct", "Struct of variables (with multi-level via linked list)"), clEnumValN(NCHybrid, "hybrid", "List of pointers to structs of variables, one per level."), clEnumValEnd), cl::init(NCHybrid)); /****************************************************************************************/ /*//////////////////////////////////////////////////////////////////////////////////////// // NESTED VARIABLE HELPERS ////////////////////////////////////////////////////////////////////////////////////////*/ static FuncDeclaration* getParentFunc(Dsymbol* sym, bool stopOnStatic) { if (!sym) return NULL; Dsymbol* parent = sym->parent; assert(parent); while (parent && !parent->isFuncDeclaration()) { if (stopOnStatic) { Declaration* decl = sym->isDeclaration(); if (decl && decl->isStatic()) return NULL; } parent = parent->parent; } return (parent ? parent->isFuncDeclaration() : NULL); } static void storeVariable(VarDeclaration *vd, LLValue *dst) { LLValue *value = vd->ir.irLocal->value; #if DMDV2 int ty = vd->type->ty; FuncDeclaration *fd = getParentFunc(vd, true); assert(fd && "No parent function for nested variable?"); if (fd->needsClosure() && !vd->isRef() && (ty == Tstruct || ty == Tsarray) && isaPointer(value->getType())) { // Copy structs and static arrays LLValue *mem = DtoGcMalloc(DtoType(vd->type), ".gc_mem"); DtoAggrCopy(mem, value); DtoAlignedStore(mem, dst); } else #endif // Store the address into the frame DtoAlignedStore(value, dst); } static void DtoCreateNestedContextType(FuncDeclaration* fd); DValue* DtoNestedVariable(Loc loc, Type* astype, VarDeclaration* vd, bool byref) { Logger::println("DtoNestedVariable for %s @ %s", vd->toChars(), loc.toChars()); LOG_SCOPE; //////////////////////////////////// // Locate context value Dsymbol* vdparent = vd->toParent2(); assert(vdparent); IrFunction* irfunc = gIR->func(); // Check whether we can access the needed frame FuncDeclaration *fd = irfunc->decl; while (fd != vdparent) { if (fd->isStatic()) { error(loc, "function %s cannot access frame of function %s", irfunc->decl->toPrettyChars(), vdparent->toPrettyChars()); return new DVarValue(astype, vd, llvm::UndefValue::get(getPtrToType(DtoType(astype)))); } fd = getParentFunc(fd, false); assert(fd); } // is the nested variable in this scope? if (vdparent == irfunc->decl) { LLValue* val = vd->ir.getIrValue(); return new DVarValue(astype, vd, val); } // get the nested context LLValue* ctx = 0; if (irfunc->decl->isMember2()) { #if DMDV2 AggregateDeclaration* cd = irfunc->decl->isMember2(); LLValue* val = irfunc->thisArg; if (cd->isClassDeclaration()) val = DtoLoad(val); #else ClassDeclaration* cd = irfunc->decl->isMember2()->isClassDeclaration(); LLValue* val = DtoLoad(irfunc->thisArg); #endif ctx = DtoLoad(DtoGEPi(val, 0,cd->vthis->ir.irField->index, ".vthis")); } else if (irfunc->nestedVar) ctx = irfunc->nestedVar; else ctx = irfunc->nestArg; assert(ctx); DtoCreateNestedContextType(vdparent->isFuncDeclaration()); assert(vd->ir.irLocal); //////////////////////////////////// // Extract variable from nested context if (nestedCtx == NCArray) { LLValue* val = DtoBitCast(ctx, getPtrToType(getVoidPtrType())); val = DtoGEPi1(val, vd->ir.irLocal->nestedIndex); val = DtoAlignedLoad(val); assert(vd->ir.irLocal->value); val = DtoBitCast(val, vd->ir.irLocal->value->getType(), vd->toChars()); return new DVarValue(astype, vd, val); } else if (nestedCtx == NCHybrid) { LLValue* val = DtoBitCast(ctx, LLPointerType::getUnqual(irfunc->frameType)); Logger::cout() << "Context: " << *val << '\n'; Logger::cout() << "of type: " << *val->getType() << '\n'; unsigned vardepth = vd->ir.irLocal->nestedDepth; unsigned funcdepth = irfunc->depth; Logger::cout() << "Variable: " << vd->toChars() << '\n'; Logger::cout() << "Variable depth: " << vardepth << '\n'; Logger::cout() << "Function: " << irfunc->decl->toChars() << '\n'; Logger::cout() << "Function depth: " << funcdepth << '\n'; if (vardepth == funcdepth) { // This is not always handled above because functions without // variables accessed by nested functions don't create new frames. Logger::println("Same depth"); } else { // Load frame pointer and index that... Logger::println("Lower depth"); val = DtoGEPi(val, 0, vd->ir.irLocal->nestedDepth); Logger::cout() << "Frame index: " << *val << '\n'; val = DtoAlignedLoad(val, (std::string(".frame.") + vdparent->toChars()).c_str()); Logger::cout() << "Frame: " << *val << '\n'; } val = DtoGEPi(val, 0, vd->ir.irLocal->nestedIndex, vd->toChars()); Logger::cout() << "Addr: " << *val << '\n'; Logger::cout() << "of type: " << *val->getType() << '\n'; if (vd->ir.irLocal->byref || byref) { val = DtoAlignedLoad(val); Logger::cout() << "Was byref, now: " << *val << '\n'; Logger::cout() << "of type: " << *val->getType() << '\n'; } return new DVarValue(astype, vd, val); } else { assert(0 && "Not implemented yet"); } } void DtoNestedInit(VarDeclaration* vd) { Logger::println("DtoNestedInit for %s", vd->toChars()); LOG_SCOPE IrFunction* irfunc = gIR->func()->decl->ir.irFunc; LLValue* nestedVar = irfunc->nestedVar; if (nestedCtx == NCArray) { // alloca as usual if no value already if (!vd->ir.irLocal->value) vd->ir.irLocal->value = DtoAlloca(vd->type, vd->toChars()); // store the address into the nested vars array assert(vd->ir.irLocal->nestedIndex >= 0); LLValue* gep = DtoGEPi(nestedVar, 0, vd->ir.irLocal->nestedIndex); assert(isaPointer(vd->ir.irLocal->value)); LLValue* val = DtoBitCast(vd->ir.irLocal->value, getVoidPtrType()); DtoAlignedStore(val, gep); } else if (nestedCtx == NCHybrid) { assert(vd->ir.irLocal->value && "Nested variable without storage?"); if (!vd->isParameter() && (vd->isRef() || vd->isOut())) { unsigned vardepth = vd->ir.irLocal->nestedDepth; LLValue* val = NULL; // Retrieve frame pointer if (vardepth == irfunc->depth) { val = nestedVar; } else { FuncDeclaration *parentfunc = getParentFunc(vd, true); assert(parentfunc && "No parent function for nested variable?"); val = DtoGEPi(nestedVar, 0, vardepth); val = DtoAlignedLoad(val, (std::string(".frame.") + parentfunc->toChars()).c_str()); } val = DtoGEPi(val, 0, vd->ir.irLocal->nestedIndex, vd->toChars()); storeVariable(vd, val); } else { // Already initialized in DtoCreateNestedContext } } else { assert(0 && "Not implemented yet"); } } #if DMDV2 void DtoResolveNestedContext(Loc loc, AggregateDeclaration *decl, LLValue *value) #else void DtoResolveNestedContext(Loc loc, ClassDeclaration *decl, LLValue *value) #endif { Logger::println("Resolving nested context"); LOG_SCOPE; // get context LLValue* nest = DtoNestedContext(loc, decl); // store into right location if (!llvm::dyn_cast(nest)) { size_t idx = decl->vthis->ir.irField->index; LLValue* gep = DtoGEPi(value,0,idx,".vthis"); DtoStore(DtoBitCast(nest, gep->getType()->getContainedType(0)), gep); } } LLValue* DtoNestedContext(Loc loc, Dsymbol* sym) { Logger::println("DtoNestedContext for %s", sym->toPrettyChars()); LOG_SCOPE; IrFunction* irfunc = gIR->func(); bool fromParent = true; LLValue* val; // if this func has its own vars that are accessed by nested funcs // use its own context if (irfunc->nestedVar) { val = irfunc->nestedVar; fromParent = false; } // otherwise, it may have gotten a context from the caller else if (irfunc->nestArg) val = irfunc->nestArg; // or just have a this argument else if (irfunc->thisArg) { #if DMDV2 AggregateDeclaration* ad = irfunc->decl->isMember2(); val = ad->isClassDeclaration() ? DtoLoad(irfunc->thisArg) : irfunc->thisArg; #else ClassDeclaration* ad = irfunc->decl->isMember2()->isClassDeclaration(); val = DtoLoad(irfunc->thisArg); #endif if (!ad || !ad->vthis) return llvm::UndefValue::get(getVoidPtrType()); val = DtoLoad(DtoGEPi(val, 0,ad->vthis->ir.irField->index, ".vthis")); } else { return llvm::UndefValue::get(getVoidPtrType()); } if (nestedCtx == NCHybrid) { struct FuncDeclaration* fd = 0; #if DMDV2 if (AggregateDeclaration *ad = sym->isAggregateDeclaration()) // If sym is a nested struct or a nested class, pass the frame // of the function where sym is declared. fd = ad->toParent()->isFuncDeclaration(); else #endif if (FuncDeclaration* symfd = sym->isFuncDeclaration()) { // Make sure we've had a chance to analyze nested context usage #if DMDV2 DtoCreateNestedContextType(symfd); #else DtoDefineFunction(symfd); #endif // if this is for a function that doesn't access variables from // enclosing scopes, it doesn't matter what we pass. // Tell LLVM about it by passing an 'undef'. if (symfd && symfd->ir.irFunc->depth == -1) return llvm::UndefValue::get(getVoidPtrType()); // If sym is a nested function, and it's parent context is different than the // one we got, adjust it. fd = getParentFunc(symfd, true); } if (fd) { Logger::println("For nested function, parent is %s", fd->toChars()); FuncDeclaration* ctxfd = irfunc->decl; Logger::println("Current function is %s", ctxfd->toChars()); if (fromParent) { ctxfd = getParentFunc(ctxfd, true); assert(ctxfd && "Context from outer function, but no outer function?"); } Logger::println("Context is from %s", ctxfd->toChars()); unsigned neededDepth = fd->ir.irFunc->depth; unsigned ctxDepth = ctxfd->ir.irFunc->depth; Logger::cout() << "Needed depth: " << neededDepth << '\n'; Logger::cout() << "Context depth: " << ctxDepth << '\n'; if (neededDepth >= ctxDepth) { // assert(neededDepth <= ctxDepth + 1 && "How are we going more than one nesting level up?"); // fd needs the same context as we do, so all is well Logger::println("Calling sibling function or directly nested function"); } else { val = DtoBitCast(val, LLPointerType::getUnqual(ctxfd->ir.irFunc->frameType)); val = DtoGEPi(val, 0, neededDepth); val = DtoAlignedLoad(val, (std::string(".frame.") + fd->toChars()).c_str()); } } } Logger::cout() << "result = " << *val << '\n'; Logger::cout() << "of type " << *val->getType() << '\n'; return val; } static void DtoCreateNestedContextType(FuncDeclaration* fd) { Logger::println("DtoCreateNestedContextType for %s", fd->toChars()); LOG_SCOPE if (fd->ir.irFunc->nestedContextCreated) return; fd->ir.irFunc->nestedContextCreated = true; #if DMDV2 DtoDeclareFunction(fd); if (fd->nestedVars.empty()) { // fill nestedVars size_t nnest = fd->closureVars.dim; for (size_t i = 0; i < nnest; ++i) { VarDeclaration* vd = (VarDeclaration*)fd->closureVars.data[i]; fd->nestedVars.insert(vd); } } #endif if (nestedCtx == NCHybrid) { // 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 const LLStructType* innerFrameType = NULL; unsigned depth = -1; if (!fd->isStatic()) { if (FuncDeclaration* parfd = getParentFunc(fd, true)) { innerFrameType = parfd->ir.irFunc->frameType; if (innerFrameType) depth = parfd->ir.irFunc->depth; } } fd->ir.irFunc->depth = ++depth; Logger::cout() << "Function " << fd->toChars() << " has depth " << depth << '\n'; typedef std::vector TypeVec; TypeVec types; if (depth != 0) { assert(innerFrameType); // Add frame pointer types for all but last frame if (depth > 1) { for (unsigned i = 0; i < (depth - 1); ++i) { types.push_back(innerFrameType->getElementType(i)); } } // Add frame pointer type for last frame types.push_back(LLPointerType::getUnqual(innerFrameType)); } if (Logger::enabled()) { Logger::println("Frame types: "); LOG_SCOPE; for (TypeVec::iterator i = types.begin(); i != types.end(); ++i) Logger::cout() << **i << '\n'; } // Add the direct nested variables of this function, and update their indices to match. // TODO: optimize ordering for minimal space usage? for (std::set::iterator i=fd->nestedVars.begin(); i!=fd->nestedVars.end(); ++i) { VarDeclaration* vd = *i; if (!vd->ir.irLocal) vd->ir.irLocal = new IrLocal(vd); vd->ir.irLocal->nestedIndex = types.size(); vd->ir.irLocal->nestedDepth = depth; if (vd->isParameter()) { // Parameters already have storage associated with them (to handle byref etc.), // so handle those cases specially by storing a pointer instead of a value. assert(vd->ir.irLocal->value); LLValue* value = vd->ir.irLocal->value; const LLType* type = value->getType(); if (llvm::isa(llvm::GetUnderlyingObject(value))) // This will be copied to the nesting frame. type = type->getContainedType(0); types.push_back(type); } else if (vd->isRef() || vd->isOut()) { // Foreach variables can also be by reference, for instance. types.push_back(DtoType(vd->type->pointerTo())); } else { types.push_back(DtoType(vd->type)); } if (Logger::enabled()) { Logger::println("Nested var: %s", vd->toChars()); Logger::cout() << "of type: " << *types.back() << '\n'; } } const LLStructType* frameType = LLStructType::get(gIR->context(), types); gIR->module->addTypeName(std::string("nest.") + fd->toChars(), frameType); Logger::cout() << "frameType = " << *frameType << '\n'; // Store type in IrFunction fd->ir.irFunc->frameType = frameType; } else if (FuncDeclaration* parFunc = getParentFunc(fd, true)) { // Propagate context arg properties if the context arg is passed on unmodified. DtoCreateNestedContextType(parFunc); fd->ir.irFunc->frameType = parFunc->ir.irFunc->frameType; fd->ir.irFunc->depth = parFunc->ir.irFunc->depth; } } else { assert(0 && "Not implemented yet"); } } 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 const 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")); } 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::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; const llvm::StructType *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")); } 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::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::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. DtoStore(DtoLoad(value), gep); gep->takeName(value); vd->ir.irLocal->value = gep; vd->ir.irLocal->byref = false; } 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 and set the byref flag. storeVariable(vd, gep); vd->ir.irLocal->byref = true; } } else if (vd->isRef() || vd->isOut()) { // This slot is initialized in DtoNestedInit, to handle things like byref foreach variables // which move around in memory. vd->ir.irLocal->byref = true; } 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; vd->ir.irLocal->byref = false; } } } 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"); } }