Object* const_missing(STATE, Symbol* sym) {
Module* under;
CallFrame* call_frame = state->vm()->get_ruby_frame();
LexicalScope* scope = call_frame->lexical_scope();
if(scope->nil_p()) {
under = G(object);
} else {
under = scope->module();
}
Array* args = Array::create(state, 1);
args->set(state, 0, sym);
return under->send(state, G(sym_const_missing), args);
}
/// getMachineBasicBlocks - Populate given set using machine basic blocks which
/// have machine instructions that belong to lexical scope identified by
/// DebugLoc.
void LexicalScopes::getMachineBasicBlocks(
const DILocation *DL, SmallPtrSetImpl<const MachineBasicBlock *> &MBBs) {
MBBs.clear();
LexicalScope *Scope = getOrCreateLexicalScope(DL);
if (!Scope)
return;
if (Scope == CurrentFnLexicalScope) {
for (const auto &MBB : *MF)
MBBs.insert(&MBB);
return;
}
SmallVectorImpl<InsnRange> &InsnRanges = Scope->getRanges();
for (auto &R : InsnRanges)
MBBs.insert(R.first->getParent());
}
/// dominates - Return true if DebugLoc's lexical scope dominates at least one
/// machine instruction's lexical scope in a given machine basic block.
bool LexicalScopes::dominates(const DILocation *DL, MachineBasicBlock *MBB) {
LexicalScope *Scope = getOrCreateLexicalScope(DL);
if (!Scope)
return false;
// Current function scope covers all basic blocks in the function.
if (Scope == CurrentFnLexicalScope && MBB->getParent() == MF)
return true;
bool Result = false;
for (auto &I : *MBB) {
if (const DILocation *IDL = I.getDebugLoc())
if (LexicalScope *IScope = getOrCreateLexicalScope(IDL))
if (Scope->dominates(IScope))
return true;
}
return Result;
}
/// dominates - Return true if DebugLoc's lexical scope dominates at least one
/// machine instruction's lexical scope in a given machine basic block.
bool LexicalScopes::dominates(const MDLocation *DL, MachineBasicBlock *MBB) {
LexicalScope *Scope = getOrCreateLexicalScope(DL);
if (!Scope)
return false;
// Current function scope covers all basic blocks in the function.
if (Scope == CurrentFnLexicalScope && MBB->getParent() == MF)
return true;
bool Result = false;
for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); I != E;
++I) {
if (const MDLocation *IDL = I->getDebugLoc())
if (LexicalScope *IScope = getOrCreateLexicalScope(IDL))
if (Scope->dominates(IScope))
return true;
}
return Result;
}
// Each LexicalScope has first instruction and last instruction to mark
// beginning and end of a scope respectively. Create an inverse map that list
// scopes starts (and ends) with an instruction. One instruction may start (or
// end) multiple scopes. Ignore scopes that are not reachable.
void DebugHandlerBase::identifyScopeMarkers() {
SmallVector<LexicalScope *, 4> WorkList;
WorkList.push_back(LScopes.getCurrentFunctionScope());
while (!WorkList.empty()) {
LexicalScope *S = WorkList.pop_back_val();
const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
if (!Children.empty())
WorkList.append(Children.begin(), Children.end());
if (S->isAbstractScope())
continue;
for (const InsnRange &R : S->getRanges()) {
assert(R.first && "InsnRange does not have first instruction!");
assert(R.second && "InsnRange does not have second instruction!");
requestLabelBeforeInsn(R.first);
requestLabelAfterInsn(R.second);
}
}
}
/// getMachineBasicBlocks - Populate given set using machine basic blocks which
/// have machine instructions that belong to lexical scope identified by
/// DebugLoc.
void LexicalScopes::getMachineBasicBlocks(
const MDLocation *DL, SmallPtrSetImpl<const MachineBasicBlock *> &MBBs) {
MBBs.clear();
LexicalScope *Scope = getOrCreateLexicalScope(DL);
if (!Scope)
return;
if (Scope == CurrentFnLexicalScope) {
for (const auto &MBB : *MF)
MBBs.insert(&MBB);
return;
}
SmallVectorImpl<InsnRange> &InsnRanges = Scope->getRanges();
for (SmallVectorImpl<InsnRange>::iterator I = InsnRanges.begin(),
E = InsnRanges.end();
I != E; ++I) {
InsnRange &R = *I;
MBBs.insert(R.first->getParent());
}
}
/// constructScopeNest
void LexicalScopes::constructScopeNest(LexicalScope *Scope) {
assert (Scope && "Unable to calculate scop edominance graph!");
SmallVector<LexicalScope *, 4> WorkStack;
WorkStack.push_back(Scope);
unsigned Counter = 0;
while (!WorkStack.empty()) {
LexicalScope *WS = WorkStack.back();
const SmallVector<LexicalScope *, 4> &Children = WS->getChildren();
bool visitedChildren = false;
for (SmallVector<LexicalScope *, 4>::const_iterator SI = Children.begin(),
SE = Children.end(); SI != SE; ++SI) {
LexicalScope *ChildScope = *SI;
if (!ChildScope->getDFSOut()) {
WorkStack.push_back(ChildScope);
visitedChildren = true;
ChildScope->setDFSIn(++Counter);
break;
}
}
if (!visitedChildren) {
WorkStack.pop_back();
WS->setDFSOut(++Counter);
}
}
}
void CodeViewDebug::collectVariableInfoFromMMITable(
DenseSet<InlinedVariable> &Processed) {
const TargetSubtargetInfo &TSI = Asm->MF->getSubtarget();
const TargetFrameLowering *TFI = TSI.getFrameLowering();
const TargetRegisterInfo *TRI = TSI.getRegisterInfo();
for (const MachineModuleInfo::VariableDbgInfo &VI :
MMI->getVariableDbgInfo()) {
if (!VI.Var)
continue;
assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
"Expected inlined-at fields to agree");
Processed.insert(InlinedVariable(VI.Var, VI.Loc->getInlinedAt()));
LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
// If variable scope is not found then skip this variable.
if (!Scope)
continue;
// Get the frame register used and the offset.
unsigned FrameReg = 0;
int FrameOffset = TFI->getFrameIndexReference(*Asm->MF, VI.Slot, FrameReg);
uint16_t CVReg = TRI->getCodeViewRegNum(FrameReg);
// Calculate the label ranges.
LocalVarDefRange DefRange = createDefRangeMem(CVReg, FrameOffset);
for (const InsnRange &Range : Scope->getRanges()) {
const MCSymbol *Begin = getLabelBeforeInsn(Range.first);
const MCSymbol *End = getLabelAfterInsn(Range.second);
End = End ? End : Asm->getFunctionEnd();
DefRange.Ranges.emplace_back(Begin, End);
}
LocalVariable Var;
Var.DIVar = VI.Var;
Var.DefRanges.emplace_back(std::move(DefRange));
recordLocalVariable(std::move(Var), VI.Loc->getInlinedAt());
}
}
/// constructScopeNest
void LexicalScopes::constructScopeNest(LexicalScope *Scope) {
assert(Scope && "Unable to calculate scope dominance graph!");
SmallVector<LexicalScope *, 4> WorkStack;
WorkStack.push_back(Scope);
unsigned Counter = 0;
while (!WorkStack.empty()) {
LexicalScope *WS = WorkStack.back();
const SmallVectorImpl<LexicalScope *> &Children = WS->getChildren();
bool visitedChildren = false;
for (auto &ChildScope : Children)
if (!ChildScope->getDFSOut()) {
WorkStack.push_back(ChildScope);
visitedChildren = true;
ChildScope->setDFSIn(++Counter);
break;
}
if (!visitedChildren) {
WorkStack.pop_back();
WS->setDFSOut(++Counter);
}
}
}
/// getMachineBasicBlocks - Populate given set using machine basic blocks which
/// have machine instructions that belong to lexical scope identified by
/// DebugLoc.
void LexicalScopes::
getMachineBasicBlocks(DebugLoc DL,
SmallPtrSet<const MachineBasicBlock*, 4> &MBBs) {
MBBs.clear();
LexicalScope *Scope = getOrCreateLexicalScope(DL);
if (!Scope)
return;
if (Scope == CurrentFnLexicalScope) {
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I)
MBBs.insert(I);
return;
}
SmallVector<InsnRange, 4> &InsnRanges = Scope->getRanges();
for (SmallVector<InsnRange, 4>::iterator I = InsnRanges.begin(),
E = InsnRanges.end(); I != E; ++I) {
InsnRange &R = *I;
MBBs.insert(R.first->getParent());
}
}
/// assignInstructionRanges - Find ranges of instructions covered by each
/// lexical scope.
void LexicalScopes::assignInstructionRanges(
SmallVectorImpl<InsnRange> &MIRanges,
DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap) {
LexicalScope *PrevLexicalScope = nullptr;
for (const auto &R : MIRanges) {
LexicalScope *S = MI2ScopeMap.lookup(R.first);
assert(S && "Lost LexicalScope for a machine instruction!");
if (PrevLexicalScope && !PrevLexicalScope->dominates(S))
PrevLexicalScope->closeInsnRange(S);
S->openInsnRange(R.first);
S->extendInsnRange(R.second);
PrevLexicalScope = S;
}
if (PrevLexicalScope)
PrevLexicalScope->closeInsnRange();
}
/// assignInstructionRanges - Find ranges of instructions covered by each
/// lexical scope.
void LexicalScopes::
assignInstructionRanges(SmallVectorImpl<InsnRange> &MIRanges,
DenseMap<const MachineInstr *, LexicalScope *> &MI2ScopeMap)
{
LexicalScope *PrevLexicalScope = NULL;
for (SmallVectorImpl<InsnRange>::const_iterator RI = MIRanges.begin(),
RE = MIRanges.end(); RI != RE; ++RI) {
const InsnRange &R = *RI;
LexicalScope *S = MI2ScopeMap.lookup(R.first);
assert (S && "Lost LexicalScope for a machine instruction!");
if (PrevLexicalScope && !PrevLexicalScope->dominates(S))
PrevLexicalScope->closeInsnRange(S);
S->openInsnRange(R.first);
S->extendInsnRange(R.second);
PrevLexicalScope = S;
}
if (PrevLexicalScope)
PrevLexicalScope->closeInsnRange();
}
void UserValue::computeIntervals(MachineRegisterInfo &MRI,
const TargetRegisterInfo &TRI,
LiveIntervals &LIS, LexicalScopes &LS) {
SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
// Collect all defs to be extended (Skipping undefs).
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
if (I.value() != UndefLocNo)
Defs.push_back(std::make_pair(I.start(), I.value()));
// Extend all defs, and possibly add new ones along the way.
for (unsigned i = 0; i != Defs.size(); ++i) {
SlotIndex Idx = Defs[i].first;
unsigned LocNo = Defs[i].second;
const MachineOperand &Loc = locations[LocNo];
if (!Loc.isReg()) {
extendDef(Idx, LocNo, nullptr, nullptr, nullptr, LIS);
continue;
}
// Register locations are constrained to where the register value is live.
if (TargetRegisterInfo::isVirtualRegister(Loc.getReg())) {
LiveInterval *LI = nullptr;
const VNInfo *VNI = nullptr;
if (LIS.hasInterval(Loc.getReg())) {
LI = &LIS.getInterval(Loc.getReg());
VNI = LI->getVNInfoAt(Idx);
}
SmallVector<SlotIndex, 16> Kills;
extendDef(Idx, LocNo, LI, VNI, &Kills, LIS);
if (LI)
addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
continue;
}
// For physregs, use the live range of the first regunit as a guide.
unsigned Unit = *MCRegUnitIterator(Loc.getReg(), &TRI);
LiveRange *LR = &LIS.getRegUnit(Unit);
const VNInfo *VNI = LR->getVNInfoAt(Idx);
// Don't track copies from physregs, it is too expensive.
extendDef(Idx, LocNo, LR, VNI, nullptr, LIS);
}
// Erase all the undefs.
for (LocMap::iterator I = locInts.begin(); I.valid();)
if (I.value() == UndefLocNo)
I.erase();
else
++I;
// The computed intervals may extend beyond the range of the debug
// location's lexical scope. In this case, splitting of an interval
// can result in an interval outside of the scope being created,
// causing extra unnecessary DBG_VALUEs to be emitted. To prevent
// this, trim the intervals to the lexical scope.
LexicalScope *Scope = LS.findLexicalScope(dl);
if (!Scope)
return;
SlotIndex PrevEnd;
LocMap::iterator I = locInts.begin();
// Iterate over the lexical scope ranges. Each time round the loop
// we check the intervals for overlap with the end of the previous
// range and the start of the next. The first range is handled as
// a special case where there is no PrevEnd.
for (const InsnRange &Range : Scope->getRanges()) {
SlotIndex RStart = LIS.getInstructionIndex(*Range.first);
SlotIndex REnd = LIS.getInstructionIndex(*Range.second);
// At the start of each iteration I has been advanced so that
// I.stop() >= PrevEnd. Check for overlap.
if (PrevEnd && I.start() < PrevEnd) {
SlotIndex IStop = I.stop();
unsigned LocNo = I.value();
// Stop overlaps previous end - trim the end of the interval to
// the scope range.
I.setStopUnchecked(PrevEnd);
++I;
// If the interval also overlaps the start of the "next" (i.e.
// current) range create a new interval for the remainder (which
// may be further trimmed).
if (RStart < IStop)
I.insert(RStart, IStop, LocNo);
}
// Advance I so that I.stop() >= RStart, and check for overlap.
I.advanceTo(RStart);
if (!I.valid())
return;
if (I.start() < RStart) {
// Interval start overlaps range - trim to the scope range.
I.setStartUnchecked(RStart);
// Remember that this interval was trimmed.
trimmedDefs.insert(RStart);
}
// The end of a lexical scope range is the last instruction in the
// range. To convert to an interval we need the index of the
// instruction after it.
REnd = REnd.getNextIndex();
// Advance I to first interval outside current range.
I.advanceTo(REnd);
if (!I.valid())
return;
PrevEnd = REnd;
}
// Check for overlap with end of final range.
if (PrevEnd && I.start() < PrevEnd)
I.setStopUnchecked(PrevEnd);
}
Object* const_get(STATE, Symbol* name, ConstantMissingReason* reason, Object* filter, bool replace_autoload) {
LexicalScope *cur;
Object* result;
*reason = vNonExistent;
CallFrame* frame = state->vm()->get_ruby_frame();
// Ok, this has to be explained or it will be considered black magic.
// The scope chain always ends with an entry at the top that contains
// a parent of nil, and a module of Object. This entry is put in
// regardless of lexical scoping, it's the fallback scope (the default
// scope). This is not case when deriving from BasicObject, which is
// explained later.
//
// When looking up a constant, we don't want to consider the fallback
// scope (ie, Object) initially because we need to lookup up
// the superclass chain first, because falling back on the default.
//
// The rub comes from the fact that if a user explicitly opens up
// Object in their code, we DO consider it. Like:
//
// class Idiot
// A = 2
// end
//
// class ::Object
// A = 1
// class Stupid < Idiot
// def foo
// p A
// end
// end
// end
//
// In this code, when A is looked up, Object must be considering during
// the scope walk, NOT during the superclass walk.
//
// So, in this case, foo would print "1", not "2".
//
// As indicated above, the fallback scope isn't used when the superclass
// chain directly rooted from BasicObject. To determine this is the
// case, we record whether Object is seen when looking up the superclass
// chain. If Object isn't seen, this means we are directly deriving from
// BasicObject.
cur = frame->lexical_scope();
while(!cur->nil_p()) {
// Detect the toplevel scope (the default) and get outta dodge.
if(cur->top_level_p(state)) break;
result = cur->module()->get_const(state, name, G(sym_private), reason, false, replace_autoload);
if(*reason == vFound) {
if(result != filter) return result;
*reason = vNonExistent;
}
cur = cur->parent();
}
// Now look up the superclass chain.
Module *fallback = G(object);
cur = frame->lexical_scope();
if(!cur->nil_p()) {
bool object_seen = false;
Module* mod = cur->module();
while(!mod->nil_p()) {
if(mod == G(object)) {
object_seen = true;
}
if(!object_seen && mod == G(basicobject)) {
fallback = NULL;
}
result = mod->get_const(state, name, G(sym_private), reason, false, replace_autoload);
if(*reason == vFound) {
if(result != filter) return result;
*reason = vNonExistent;
}
mod = mod->superclass();
}
}
// Lastly, check the fallback scope (=Object) specifically if needed
if(fallback) {
result = fallback->get_const(state, name, G(sym_private), reason, true, replace_autoload);
if(*reason == vFound) {
if(result != filter) return result;
*reason = vNonExistent;
}
}
return cNil;
}
