[DWARFVerifier] Use the new location list api

Summary:
Instead of going to the debug_loc section directly, use new
DWARFDie::getLocations instead. This means that the code will now
automatically support debug_loclists sections.

This is the last usage of the old debug_loc methods, and they can now be
removed.

Reviewers: dblaikie, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, probinson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70534

3 files changed, 25 insertions, 79 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 3071f637b5a..f7b3fb495f9 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -746,7 +746,6 @@ const DWARFDebugLoc *DWARFContext::getDebugLoc() {
                                getUnitAtIndex(0)->getAddressByteSize())
           : DWARFDataExtractor("", isLittleEndian(), 0);
   Loc.reset(new DWARFDebugLoc(std::move(LocData)));
-  Loc->parse();
   return Loc.get();
 }
 
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
index 8b84822914d..baa35eb813c 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
@@ -166,15 +166,6 @@ Error DWARFLocationTable::visitAbsoluteLocationList(
   });
 }
 
-DWARFDebugLoc::LocationList const *
-DWARFDebugLoc::getLocationListAtOffset(uint64_t Offset) const {
-  auto It = partition_point(
-      Locations, [=](const LocationList &L) { return L.Offset < Offset; });
-  if (It != Locations.end() && It->Offset == Offset)
-    return &(*It);
-  return nullptr;
-}
-
 void DWARFDebugLoc::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
                          DIDumpOptions DumpOpts,
                          Optional<uint64_t> DumpOffset) const {
@@ -235,32 +226,6 @@ Error DWARFDebugLoc::visitLocationList(
   return Error::success();
 }
 
-Expected<DWARFDebugLoc::LocationList>
-DWARFDebugLoc::parseOneLocationList(uint64_t *Offset) {
-  LocationList LL;
-  LL.Offset = *Offset;
-
-  Error E = visitLocationList(Offset, [&](const DWARFLocationEntry &E) {
-    LL.Entries.push_back(E);
-    return true;
-  });
-  if (E)
-    return std::move(E);
-  return std::move(LL);
-}
-
-void DWARFDebugLoc::parse() {
-  uint64_t Offset = 0;
-  while (Offset < Data.getData().size()) {
-    if (auto LL = parseOneLocationList(&Offset))
-      Locations.push_back(std::move(*LL));
-    else {
-      logAllUnhandledErrors(LL.takeError(), WithColor::error());
-      break;
-    }
-  }
-}
-
 void DWARFDebugLoc::dumpRawEntry(const DWARFLocationEntry &Entry,
                                  raw_ostream &OS, unsigned Indent) const {
   uint64_t Value0, Value1;
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
index d4cadd0f252..a8f95043fc8 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -468,27 +468,21 @@ unsigned DWARFVerifier::verifyDebugInfoAttribute(const DWARFDie &Die,
     ReportError("DIE has invalid DW_AT_stmt_list encoding:");
     break;
   case DW_AT_location: {
-    auto VerifyLocationExpr = [&](ArrayRef<uint8_t> D) {
+    if (Expected<std::vector<DWARFLocationExpression>> Loc =
+            Die.getLocations(DW_AT_location)) {
       DWARFUnit *U = Die.getDwarfUnit();
-      DataExtractor Data(toStringRef(D), DCtx.isLittleEndian(), 0);
-      DWARFExpression Expression(Data, U->getVersion(),
-                                 U->getAddressByteSize());
-      bool Error = llvm::any_of(Expression, [](DWARFExpression::Operation &Op) {
-        return Op.isError();
-      });
-      if (Error || !Expression.verify(U))
-        ReportError("DIE contains invalid DWARF expression:");
-    };
-    if (Optional<ArrayRef<uint8_t>> Expr = AttrValue.Value.getAsBlock()) {
-      // Verify inlined location.
-      VerifyLocationExpr(*Expr);
-    } else if (auto LocOffset = AttrValue.Value.getAsSectionOffset()) {
-      // Verify location list.
-      if (auto DebugLoc = DCtx.getDebugLoc())
-        if (auto LocList = DebugLoc->getLocationListAtOffset(*LocOffset))
-          for (const auto &Entry : LocList->Entries)
-            VerifyLocationExpr(Entry.Loc);
-    }
+      for (const auto &Entry : *Loc) {
+        DataExtractor Data(toStringRef(Entry.Expr), DCtx.isLittleEndian(), 0);
+        DWARFExpression Expression(Data, U->getVersion(),
+                                   U->getAddressByteSize());
+        bool Error = any_of(Expression, [](DWARFExpression::Operation &Op) {
+          return Op.isError();
+        });
+        if (Error || !Expression.verify(U))
+          ReportError("DIE contains invalid DWARF expression:");
+      }
+    } else
+      ReportError(toString(Loc.takeError()));
     break;
   }
   case DW_AT_specification:
@@ -1278,36 +1272,24 @@ unsigned DWARFVerifier::verifyNameIndexEntries(
 }
 
 static bool isVariableIndexable(const DWARFDie &Die, DWARFContext &DCtx) {
-  Optional<DWARFFormValue> Location = Die.findRecursively(DW_AT_location);
-  if (!Location)
+  Expected<std::vector<DWARFLocationExpression>> Loc =
+      Die.getLocations(DW_AT_location);
+  if (!Loc) {
+    consumeError(Loc.takeError());
     return false;
-
-  auto ContainsInterestingOperators = [&](ArrayRef<uint8_t> D) {
-    DWARFUnit *U = Die.getDwarfUnit();
-    DataExtractor Data(toStringRef(D), DCtx.isLittleEndian(), U->getAddressByteSize());
+  }
+  DWARFUnit *U = Die.getDwarfUnit();
+  for (const auto &Entry : *Loc) {
+    DataExtractor Data(toStringRef(Entry.Expr), DCtx.isLittleEndian(),
+                       U->getAddressByteSize());
     DWARFExpression Expression(Data, U->getVersion(), U->getAddressByteSize());
-    return any_of(Expression, [](DWARFExpression::Operation &Op) {
+    bool IsInteresting = any_of(Expression, [](DWARFExpression::Operation &Op) {
       return !Op.isError() && (Op.getCode() == DW_OP_addr ||
                                Op.getCode() == DW_OP_form_tls_address ||
                                Op.getCode() == DW_OP_GNU_push_tls_address);
     });
-  };
-
-  if (Optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
-    // Inlined location.
-    if (ContainsInterestingOperators(*Expr))
+    if (IsInteresting)
       return true;
-  } else if (Optional<uint64_t> Offset = Location->getAsSectionOffset()) {
-    // Location list.
-    if (const DWARFDebugLoc *DebugLoc = DCtx.getDebugLoc()) {
-      if (const DWARFDebugLoc::LocationList *LocList =
-              DebugLoc->getLocationListAtOffset(*Offset)) {
-        if (any_of(LocList->Entries, [&](const DWARFLocationEntry &E) {
-              return ContainsInterestingOperators(E.Loc);
-            }))
-          return true;
-      }
-    }
   }
   return false;
 }