Teach dwarf writer to handle complex address expression for .debug_loc entries.
This fixes clang generated blocks' variables' debug info.
Radar 9279956.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130373 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index d830e97..86e8bb6 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -749,33 +749,49 @@
return MachineLocation();
}
+/// getDwarfRegOpSize - get size required to emit given machine location using
+/// dwarf encoding.
+unsigned AsmPrinter::getDwarfRegOpSize(const MachineLocation &MLoc) const {
+ const TargetRegisterInfo *RI = TM.getRegisterInfo();
+ unsigned DWReg = RI->getDwarfRegNum(MLoc.getReg(), false);
+ if (int Offset = MLoc.getOffset()) {
+ // If the value is at a certain offset from frame register then
+ // use DW_OP_breg.
+ if (DWReg < 32)
+ return 1 + MCAsmInfo::getSLEB128Size(Offset);
+ else
+ return 1 + MCAsmInfo::getULEB128Size(MLoc.getReg())
+ + MCAsmInfo::getSLEB128Size(Offset);
+ }
+ if (DWReg < 32)
+ return 1;
+
+ return 1 + MCAsmInfo::getULEB128Size(DWReg);
+}
+
/// EmitDwarfRegOp - Emit dwarf register operation.
void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
- const TargetRegisterInfo *RI = TM.getRegisterInfo();
- unsigned Reg = RI->getDwarfRegNum(MLoc.getReg(), false);
+ const TargetRegisterInfo *TRI = TM.getRegisterInfo();
+ unsigned Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
if (int Offset = MLoc.getOffset()) {
- // If the value is at a certain offset from frame register then
- // use DW_OP_fbreg.
- unsigned OffsetSize = Offset ? MCAsmInfo::getSLEB128Size(Offset) : 1;
- OutStreamer.AddComment("Loc expr size");
- EmitInt16(1 + OffsetSize);
- OutStreamer.AddComment(
- dwarf::OperationEncodingString(dwarf::DW_OP_fbreg));
- EmitInt8(dwarf::DW_OP_fbreg);
- OutStreamer.AddComment("Offset");
+ if (Reg < 32) {
+ OutStreamer.AddComment(
+ dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
+ EmitInt8(dwarf::DW_OP_breg0 + Reg);
+ } else {
+ OutStreamer.AddComment("DW_OP_bregx");
+ EmitInt8(dwarf::DW_OP_bregx);
+ OutStreamer.AddComment(Twine(Reg));
+ EmitULEB128(Reg);
+ }
EmitSLEB128(Offset);
} else {
if (Reg < 32) {
- OutStreamer.AddComment("Loc expr size");
- EmitInt16(1);
OutStreamer.AddComment(
dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
EmitInt8(dwarf::DW_OP_reg0 + Reg);
} else {
- OutStreamer.AddComment("Loc expr size");
- EmitInt16(1 + MCAsmInfo::getULEB128Size(Reg));
- OutStreamer.AddComment(
- dwarf::OperationEncodingString(dwarf::DW_OP_regx));
+ OutStreamer.AddComment("DW_OP_regx");
EmitInt8(dwarf::DW_OP_regx);
OutStreamer.AddComment(Twine(Reg));
EmitULEB128(Reg);
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index fa5cdd2..7ce0cfe 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -258,15 +258,22 @@
unsigned Attribute,
const MachineLocation &Location) {
DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
-
- if (Location.isReg())
- addRegisterOp(Block, Location.getReg());
+ unsigned N = DV->getNumAddrElements();
+ unsigned i = 0;
+ if (Location.isReg()) {
+ if (N >= 2 && DV->getAddrElement(0) == DIBuilder::OpPlus) {
+ // If first address element is OpPlus then emit
+ // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
+ addRegisterOffset(Block, Location.getReg(), DV->getAddrElement(1));
+ i = 2;
+ } else
+ addRegisterOp(Block, Location.getReg());
+ }
else
addRegisterOffset(Block, Location.getReg(), Location.getOffset());
- for (unsigned i = 0, N = DV->getNumAddrElements(); i < N; ++i) {
+ for (;i < N; ++i) {
uint64_t Element = DV->getAddrElement(i);
-
if (Element == DIBuilder::OpPlus) {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
addUInt(Block, 0, dwarf::DW_FORM_udata, DV->getAddrElement(++i));
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d99faf9..26da800 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1466,7 +1466,7 @@
}
// The value is valid until the next DBG_VALUE or clobber.
- DotDebugLocEntries.push_back(DotDebugLocEntry(FLabel, SLabel, MLoc));
+ DotDebugLocEntries.push_back(DotDebugLocEntry(FLabel, SLabel, MLoc, Var));
}
DotDebugLocEntries.push_back(DotDebugLocEntry());
}
@@ -2721,7 +2721,39 @@
} else {
Asm->OutStreamer.EmitSymbolValue(Entry.Begin, Size, 0);
Asm->OutStreamer.EmitSymbolValue(Entry.End, Size, 0);
- Asm->EmitDwarfRegOp(Entry.Loc);
+ DIVariable DV(Entry.Variable);
+ if (DV.hasComplexAddress()) {
+ unsigned N = DV.getNumAddrElements();
+ unsigned i = 0;
+ Asm->OutStreamer.AddComment("Loc expr size");
+ if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
+ // If first address element is OpPlus then emit
+ // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
+ MachineLocation Loc(Entry.Loc.getReg(), DV.getAddrElement(1));
+ Asm->EmitInt16(Asm->getDwarfRegOpSize(Loc) + N - 2);
+ Asm->EmitDwarfRegOp(Loc);
+// Asm->EmitULEB128(DV.getAddrElement(1));
+ i = 2;
+ } else {
+ Asm->EmitInt16(Asm->getDwarfRegOpSize(Entry.Loc) + N);
+ Asm->EmitDwarfRegOp(Entry.Loc);
+ }
+
+ // Emit remaining complex address elements.
+ for (; i < N; ++i) {
+ uint64_t Element = DV.getAddrElement(i);
+ if (Element == DIBuilder::OpPlus) {
+ Asm->EmitInt8(dwarf::DW_OP_plus_uconst);
+ Asm->EmitULEB128(DV.getAddrElement(++i));
+ } else if (Element == DIBuilder::OpDeref)
+ Asm->EmitInt8(dwarf::DW_OP_deref);
+ else llvm_unreachable("unknown Opcode found in complex address");
+ }
+ } else {
+ Asm->OutStreamer.AddComment("Loc expr size");
+ Asm->EmitInt16(Asm->getDwarfRegOpSize(Entry.Loc));
+ Asm->EmitDwarfRegOp(Entry.Loc);
+ }
}
}
}
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 892224b..25f2675 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -66,10 +66,12 @@
const MCSymbol *Begin;
const MCSymbol *End;
MachineLocation Loc;
+ const MDNode *Variable;
bool Merged;
- DotDebugLocEntry() : Begin(0), End(0), Merged(false) {}
- DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L)
- : Begin(B), End(E), Loc(L), Merged(false) {}
+ DotDebugLocEntry() : Begin(0), End(0), Variable(0), Merged(false) {}
+ DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L,
+ const MDNode *V)
+ : Begin(B), End(E), Loc(L), Variable(V), Merged(false) {}
/// Empty entries are also used as a trigger to emit temp label. Such
/// labels are referenced is used to find debug_loc offset for a given DIE.
bool isEmpty() { return Begin == 0 && End == 0; }