[PATCH] D118098: [InstrProf][correlation] Read DWARFv5 `OP_addrx` location

[Ellis Hoag via Phabricator via llvm-commits]

ellis created this revision.
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Correctly read `OP_addrx` type encodings for DWARFv5 locations.

Also, return an error when no profile metadata is found rather than crashing.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D118098

Files:
  llvm/lib/ProfileData/InstrProfCorrelator.cpp


Index: llvm/lib/ProfileData/InstrProfCorrelator.cpp
===================================================================
--- llvm/lib/ProfileData/InstrProfCorrelator.cpp
+++ llvm/lib/ProfileData/InstrProfCorrelator.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ProfileData/InstrProfCorrelator.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugAddr.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/FileSystem.h"
@@ -127,6 +128,10 @@
 Error InstrProfCorrelatorImpl<IntPtrT>::correlateProfileData() {
   assert(Data.empty() && CompressedNames.empty() && Names.empty());
   correlateProfileDataImpl();
+  if (Data.empty() || Names.empty())
+    return make_error<InstrProfError>(
+        instrprof_error::unable_to_correlate_profile,
+        "could not find any profile metadata in debug info");
   auto Result =
       collectPGOFuncNameStrings(Names, /*doCompression=*/true, CompressedNames);
   CounterOffsets.clear();
@@ -167,13 +172,27 @@
     return {};
   }
   auto &DU = *Die.getDwarfUnit();
+  bool isLE = DICtx->isLittleEndian();
+  auto AddressSize = DU.getAddressByteSize();
+  const auto &DObj = DICtx->getDWARFObj();
+  DWARFDataExtractor AddrSectionData(DObj, DObj.getAddrSection(), isLE,
+                                     AddressSize);
   for (auto &Location : *Locations) {
-    auto AddressSize = DU.getAddressByteSize();
-    DataExtractor Data(Location.Expr, DICtx->isLittleEndian(), AddressSize);
+    DataExtractor Data(Location.Expr, isLE, AddressSize);
     DWARFExpression Expr(Data, AddressSize);
-    for (auto &Op : Expr)
-      if (Op.getCode() == dwarf::DW_OP_addr)
+    for (auto &Op : Expr) {
+      if (Op.getCode() == dwarf::DW_OP_addr) {
         return Op.getRawOperand(0);
+      } else if (Op.getCode() == dwarf::DW_OP_addrx) {
+        uint64_t Index = Op.getRawOperand(0);
+        auto Offset = DU.getAddrOffsetSectionBase();
+        if (!Offset.hasValue())
+          continue;
+        // FIXME: Perhaps we should be using DWARFDebugAddrTable
+        uint64_t RawOffset = *Offset + Index * AddressSize;
+        return AddrSectionData.getAddress(&RawOffset);
+      }
+    }
   }
   return {};
 }


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