DebugLoc associated with a machine instruction is used to emit location entries. DebugLoc associated with a DBG_VALUE is used to identify lexical scope of the variable. After register allocation, while inserting DBG_VALUE remember original debug location for the first instruction and reuse it, otherwise dwarf writer may be mislead in identifying the variable's scope.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124845 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveDebugVariables.cpp b/lib/CodeGen/LiveDebugVariables.cpp
index 38b270d..853ec1a 100644
--- a/lib/CodeGen/LiveDebugVariables.cpp
+++ b/lib/CodeGen/LiveDebugVariables.cpp
@@ -79,7 +79,8 @@
class UserValue {
const MDNode *variable; ///< The debug info variable we are part of.
unsigned offset; ///< Byte offset into variable.
-
+ DebugLoc dl; ///< The debug location for the variable. This is
+ ///< used by dwarf writer to find lexical scope.
UserValue *leader; ///< Equivalence class leader.
UserValue *next; ///< Next value in equivalence class, or null.
@@ -104,8 +105,9 @@
public:
/// UserValue - Create a new UserValue.
- UserValue(const MDNode *var, unsigned o, LocMap::Allocator &alloc)
- : variable(var), offset(o), leader(this), next(0), locInts(alloc)
+ UserValue(const MDNode *var, unsigned o, DebugLoc L,
+ LocMap::Allocator &alloc)
+ : variable(var), offset(o), dl(L), leader(this), next(0), locInts(alloc)
{}
/// getLeader - Get the leader of this value's equivalence class.
@@ -192,6 +194,11 @@
void emitDebugValues(VirtRegMap *VRM,
LiveIntervals &LIS, const TargetInstrInfo &TRI);
+ /// findDebugLoc - Return DebugLoc used for this DBG_VALUE instruction. A
+ /// variable may have more than one corresponding DBG_VALUE instructions.
+ /// Only first one needs DebugLoc to identify variable's lexical scope
+ /// in source file.
+ DebugLoc findDebugLoc();
void print(raw_ostream&, const TargetRegisterInfo*);
};
} // namespace
@@ -218,7 +225,7 @@
UVMap userVarMap;
/// getUserValue - Find or create a UserValue.
- UserValue *getUserValue(const MDNode *Var, unsigned Offset);
+ UserValue *getUserValue(const MDNode *Var, unsigned Offset, DebugLoc DL);
/// lookupVirtReg - Find the EC leader for VirtReg or null.
UserValue *lookupVirtReg(unsigned VirtReg);
@@ -315,7 +322,8 @@
}
}
-UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset) {
+UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset,
+ DebugLoc DL) {
UserValue *&Leader = userVarMap[Var];
if (Leader) {
UserValue *UV = Leader->getLeader();
@@ -325,7 +333,7 @@
return UV;
}
- UserValue *UV = new UserValue(Var, Offset, allocator);
+ UserValue *UV = new UserValue(Var, Offset, DL, allocator);
userValues.push_back(UV);
Leader = UserValue::merge(Leader, UV);
return UV;
@@ -354,7 +362,7 @@
// Get or create the UserValue for (variable,offset).
unsigned Offset = MI->getOperand(1).getImm();
const MDNode *Var = MI->getOperand(2).getMetadata();
- UserValue *UV = getUserValue(Var, Offset);
+ UserValue *UV = getUserValue(Var, Offset, MI->getDebugLoc());
// If the location is a virtual register, make sure it is mapped.
if (MI->getOperand(0).isReg()) {
@@ -581,10 +589,10 @@
DEBUG(print(dbgs(), &TRI));
}
-/// findInsertLocation - Find an iterator and DebugLoc for inserting a DBG_VALUE
+/// findInsertLocation - Find an iterator for inserting a DBG_VALUE
/// instruction.
static MachineBasicBlock::iterator
-findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx, DebugLoc &DL,
+findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
LiveIntervals &LIS) {
SlotIndex Start = LIS.getMBBStartIdx(MBB);
Idx = Idx.getBaseIndex();
@@ -595,46 +603,47 @@
// We've reached the beginning of MBB.
if (Idx == Start) {
MachineBasicBlock::iterator I = MBB->SkipPHIsAndLabels(MBB->begin());
- if (I != MBB->end())
- DL = I->getDebugLoc();
return I;
}
Idx = Idx.getPrevIndex();
}
- // We found an instruction. The insert point is after the instr.
- DL = MI->getDebugLoc();
+
// Don't insert anything after the first terminator, though.
return MI->getDesc().isTerminator() ? MBB->getFirstTerminator() :
llvm::next(MachineBasicBlock::iterator(MI));
}
+DebugLoc UserValue::findDebugLoc() {
+ DebugLoc D = dl;
+ dl = DebugLoc();
+ return D;
+}
void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
unsigned LocNo,
LiveIntervals &LIS,
const TargetInstrInfo &TII) {
- DebugLoc DL;
- MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, DL, LIS);
+ MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
MachineOperand &Loc = locations[LocNo];
// Frame index locations may require a target callback.
if (Loc.isFI()) {
MachineInstr *MI = TII.emitFrameIndexDebugValue(*MBB->getParent(),
- Loc.getIndex(), offset, variable, DL);
+ Loc.getIndex(), offset, variable,
+ findDebugLoc());
if (MI) {
MBB->insert(I, MI);
return;
}
}
// This is not a frame index, or the target is happy with a standard FI.
- BuildMI(*MBB, I, DL, TII.get(TargetOpcode::DBG_VALUE))
+ BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE))
.addOperand(Loc).addImm(offset).addMetadata(variable);
}
void UserValue::insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
LiveIntervals &LIS, const TargetInstrInfo &TII) {
- DebugLoc DL;
- MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, DL, LIS);
- BuildMI(*MBB, I, DL, TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
+ MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
+ BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
.addImm(offset).addMetadata(variable);
}