ldc/gen/nested.cpp
2012-10-07 03:06:07 +02:00

541 lines
20 KiB
C++

#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 "gen/todebug.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Support/CommandLine.h"
namespace cl = llvm::cl;
/****************************************************************************************/
/*////////////////////////////////////////////////////////////////////////////////////////
// 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);
}
LLValue *dwarfValue = 0;
std::vector<LLValue*> dwarfAddr;
LLType *int64Ty = LLType::getInt64Ty(gIR->context());
// 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);
ctx = DtoLoad(DtoGEPi(val, 0, cd->vthis->ir.irField->index, ".vthis"));
#else
ClassDeclaration* cd = irfunc->decl->isMember2()->isClassDeclaration();
LLValue* val = DtoLoad(irfunc->thisArg);
ctx = DtoGEPi(val, 0, cd->vthis->ir.irField->index, ".vthis");
if (!irfunc->frameType && vd->isThisDeclaration())
{
// If the only "nested" variable is the outer this pointer, we don't
// emit a normal context, but just store the this pointer - see
// GitHub #127.
return new DVarValue(astype, vd, ctx);
}
ctx = DtoLoad(ctx);
#endif
}
else if (irfunc->nestedVar) {
ctx = irfunc->nestedVar;
dwarfValue = ctx;
} else {
ctx = DtoLoad(irfunc->nestArg);
dwarfValue = irfunc->nestArg;
if (global.params.symdebug)
dwarfOpDeref(dwarfAddr);
}
assert(ctx);
DtoCreateNestedContextType(vdparent->isFuncDeclaration());
assert(vd->ir.irLocal);
////////////////////////////////////
// Extract variable from nested context
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...
if (dwarfValue && global.params.symdebug) {
dwarfOpOffset(dwarfAddr, val, vd->ir.irLocal->nestedDepth);
dwarfOpDeref(dwarfAddr);
}
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';
}
if (dwarfValue && global.params.symdebug)
dwarfOpOffset(dwarfAddr, val, vd->ir.irLocal->nestedIndex);
val = DtoGEPi(val, 0, vd->ir.irLocal->nestedIndex, vd->toChars());
Logger::cout() << "Addr: " << *val << '\n';
Logger::cout() << "of type: " << *val->getType() << '\n';
if (byref || (vd->isParameter() && vd->ir.irParam->arg->byref)) {
val = DtoAlignedLoad(val);
//dwarfOpDeref(dwarfAddr);
Logger::cout() << "Was byref, now: " << *val << '\n';
Logger::cout() << "of type: " << *val->getType() << '\n';
}
if (dwarfValue && global.params.symdebug)
DtoDwarfLocalVariable(dwarfValue, vd, dwarfAddr);
return new DVarValue(astype, vd, val);
}
#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<llvm::UndefValue>(nest)) {
// Need to make sure the declaration has already been resolved, because
// when multiple source files are specified on the command line, the
// frontend sometimes adds "nested" (i.e. a template in module B
// instantiated from module A with a type from module A instantiates
// another template from module B) into the wrong module, messing up
// our codegen order.
DtoResolveDsymbol(decl);
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 = DtoLoad(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;
if (!ad->vthis)
return llvm::UndefValue::get(getVoidPtrType());
#else
ClassDeclaration* ad = irfunc->decl->isMember2()->isClassDeclaration();
val = DtoLoad(irfunc->thisArg);
if (!ad || !ad->vthis)
return val;
#endif
val = DtoLoad(DtoGEPi(val, 0, ad->vthis->ir.irField->index, ".vthis"));
}
else
{
// Use null instead of e.g. LLVM's undef to not break bitwise
// comparison for instances of nested struct types which don't have any
// nested references.
return llvm::ConstantPointerNull::get(getVoidPtrType());
}
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
DtoDeclareFunction(fd);
if (fd->ir.irFunc->nestedContextCreated)
return;
fd->ir.irFunc->nestedContextCreated = true;
#if DMDV2
if (fd->nestedVars.empty()) {
// fill nestedVars
size_t nnest = fd->closureVars.dim;
for (size_t i = 0; i < nnest; ++i)
{
VarDeclaration* vd = static_cast<VarDeclaration*>(fd->closureVars.data[i]);
fd->nestedVars.insert(vd);
}
}
#endif
// 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
LLStructType* innerFrameType = NULL;
unsigned depth = -1;
if (!fd->isStatic()) {
if (FuncDeclaration* parfd = getParentFunc(fd, true)) {
// Make sure the parent has already been analyzed.
DtoCreateNestedContextType(parfd);
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<LLType*> 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<VarDeclaration*>::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 will have storage associated with them (to handle byref etc.),
// so handle those cases specially by storing a pointer instead of a value.
IrParameter * irparam = vd->ir.irParam;
LLValue* value = irparam->value;
assert(value);
LLType* type = value->getType();
bool refout = vd->storage_class & (STCref | STCout);
bool lazy = vd->storage_class & STClazy;
bool byref = irparam->arg->byref;
#if STRUCTTHISREF
bool isVthisPtr = irparam->isVthis && !byref;
#else
bool isVthisPtr = irparam->isVthis;
#endif
if ((!refout && (!byref || lazy)) || isVthisPtr) {
// This will be copied to the nesting frame.
if (lazy)
type = type->getContainedType(0);
else
type = DtoType(vd->type);
} else {
}
types.push_back(type);
} else if (isSpecialRefVar(vd)) {
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';
}
}
LLStructType* frameType = LLStructType::create(gIR->context(), types,
std::string("nest.") + fd->toChars());
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;
}
}
void DtoCreateNestedContext(FuncDeclaration* fd) {
Logger::println("DtoCreateNestedContext for %s", fd->toChars());
LOG_SCOPE
DtoCreateNestedContextType(fd);
// 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
IrParameter* parm = vd->ir.irParam;
if (parm->arg->byref)
{
storeVariable(vd, gep);
}
else
{
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(parm->value), gep);
gep->takeName(parm->value);
parm->value = gep;
}
} else {
Logger::println("nested var: %s", vd->toChars());
assert(!vd->ir.irLocal->value);
vd->ir.irLocal->value = gep;
}
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;
}
}