[DebugInfo] Convert intrinsic llvm.dbg.label to MachineInstr.
In order to convert LLVM IR to MachineInstr, we need a new TargetOpcode,
DBG_LABEL, to ‘lower’ intrinsic llvm.dbg.label. The patch
creates this new TargetOpcode and convert intrinsic llvm.dbg.label to
MachineInstr through SelectionDAG.
In SelectionDAG, debug information is stored in SDDbgInfo. We create a
new data member of SDDbgInfo for labels and use the new data member,
SDDbgLabel, to create DBG_LABEL MachineInstr.
The new DBG_LABEL MachineInstr uses label metadata from LLVM IR as its
parameter. So, the backend could get metadata information of labels from
DBG_LABEL MachineInstr.
Differential Revision: https://reviews.llvm.org/D45341
Patch by Hsiangkai Wang.
llvm-svn: 331842
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 411b11f..89e047a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -911,6 +911,30 @@
return true;
}
+/// This method handles the target-independent form of DBG_LABEL, returning
+/// true if it was able to do so. A false return means the target will need
+/// to handle MI in EmitInstruction.
+static bool emitDebugLabelComment(const MachineInstr *MI, AsmPrinter &AP) {
+ if (MI->getNumOperands() != 1)
+ return false;
+
+ SmallString<128> Str;
+ raw_svector_ostream OS(Str);
+ OS << "DEBUG_LABEL: ";
+
+ const DILabel *V = MI->getDebugLabel();
+ if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
+ StringRef Name = SP->getName();
+ if (!Name.empty())
+ OS << Name << ":";
+ }
+ OS << V->getName();
+
+ // NOTE: Want this comment at start of line, don't emit with AddComment.
+ AP.OutStreamer->emitRawComment(OS.str());
+ return true;
+}
+
AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() const {
if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
MF->getFunction().needsUnwindTableEntry())
@@ -1074,6 +1098,12 @@
EmitInstruction(&MI);
}
break;
+ case TargetOpcode::DBG_LABEL:
+ if (isVerbose()) {
+ if (!emitDebugLabelComment(&MI, *this))
+ EmitInstruction(&MI);
+ }
+ break;
case TargetOpcode::IMPLICIT_DEF:
if (isVerbose()) emitImplicitDef(&MI);
break;