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/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));