Implement equal_range for the DWARF v5 accelerator table

Summary:
This patch implements the name lookup functionality of the .debug_names
accelerator table and hooks it up to "llvm-dwarfdump -find". To make the
interface of the two kinds of accelerator tables more consistent, I've
created an abstract "DWARFAcceleratorTable::Entry" class, which provides
a consistent interface to access the common functionality of the table
entries (such as getting the die offset, die tag, etc.). I've also
modified the apple table to vend entries conforming to this interface.

Reviewers: JDevlieghere, aprantl, probinson, dblaikie

Subscribers: vleschuk, clayborg, echristo, llvm-commits

Differential Revision: https://reviews.llvm.org/D43067

llvm-svn: 326003

1 files changed, 14 insertions, 12 deletions

diff --git a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
index f2a837d4cf2..b110480a2c8 100644
--- a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
+++ b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -336,6 +336,15 @@ static bool lookup(DWARFContext &DICtx, uint64_t Address, raw_ostream &OS) {
 bool collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
                                Twine Filename, raw_ostream &OS);
 
+template <typename AccelTable>
+static Optional<uint64_t> getDIEOffset(const AccelTable &Accel,
+                                       StringRef Name) {
+  for (const auto &Entry : Accel.equal_range(Name))
+    if (Optional<uint64_t> Off = Entry.getDIEOffset())
+      return *Off;
+  return None;
+}
+
 static bool dumpObjectFile(ObjectFile &Obj, DWARFContext &DICtx, Twine Filename,
                            raw_ostream &OS) {
   logAllUnhandledErrors(DICtx.loadRegisterInfo(Obj), errs(),
@@ -363,21 +372,14 @@ static bool dumpObjectFile(ObjectFile &Obj, DWARFContext &DICtx, Twine Filename,
   if (!Find.empty()) {
     DumpOffsets[DIDT_ID_DebugInfo] = [&]() -> llvm::Optional<uint64_t> {
       for (auto Name : Find) {
-        auto find = [&](const AppleAcceleratorTable &Accel)
-            -> llvm::Optional<uint64_t> {
-          for (auto Entry : Accel.equal_range(Name))
-            for (auto Atom : Entry)
-              if (auto Offset = Atom.getAsSectionOffset())
-                return Offset;
-          return None;
-        };
-        if (auto Offset = find(DICtx.getAppleNames()))
+        if (auto Offset = getDIEOffset(DICtx.getAppleNames(), Name))
+          return DumpOffsets[DIDT_ID_DebugInfo] = *Offset;
+        if (auto Offset = getDIEOffset(DICtx.getAppleTypes(), Name))
           return DumpOffsets[DIDT_ID_DebugInfo] = *Offset;
-        if (auto Offset = find(DICtx.getAppleTypes()))
+        if (auto Offset = getDIEOffset(DICtx.getAppleNamespaces(), Name))
           return DumpOffsets[DIDT_ID_DebugInfo] = *Offset;
-        if (auto Offset = find(DICtx.getAppleNamespaces()))
+        if (auto Offset = getDIEOffset(DICtx.getDebugNames(), Name))
           return DumpOffsets[DIDT_ID_DebugInfo] = *Offset;
-        // TODO: Add .debug_names support
       }
       return None;
     }();