llvm-dwarfdump: implement --find for .apple_names
This patch implements the dwarfdump option --find=<name>. This option
looks for a DIE in the accelerator tables and dumps it if found. This
initial patch only adds support for .apple_names to keep the review
small, adding the other sections and pubnames support should be
trivial though.
Differential Revision: https://reviews.llvm.org/D38282
llvm-svn: 314439
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
index f17b00e..dbe6fe5 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -12,7 +12,6 @@
#include "llvm/ADT/SmallVector.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Format.h"
@@ -52,6 +51,7 @@
HdrData.Atoms.push_back(std::make_pair(AtomType, AtomForm));
}
+ IsValid = true;
return true;
}
@@ -109,6 +109,9 @@
}
LLVM_DUMP_METHOD void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
+ if (!IsValid)
+ return;
+
// Dump the header.
OS << "Magic = " << format("0x%08x", Hdr.Magic) << '\n'
<< "Version = " << format("0x%04x", Hdr.Version) << '\n'
@@ -190,3 +193,67 @@
}
}
}
+
+DWARFAcceleratorTable::ValueIterator::ValueIterator(
+ const DWARFAcceleratorTable &AccelTable, unsigned Offset)
+ : AccelTable(&AccelTable), DataOffset(Offset) {
+ if (!AccelTable.AccelSection.isValidOffsetForDataOfSize(DataOffset, 4))
+ return;
+
+ for (const auto &Atom : AccelTable.HdrData.Atoms)
+ AtomForms.push_back(DWARFFormValue(Atom.second));
+
+ // Read the first entry.
+ NumData = AccelTable.AccelSection.getU32(&DataOffset);
+ Next();
+}
+
+void DWARFAcceleratorTable::ValueIterator::Next() {
+ assert(NumData > 0 && "attempted to increment iterator past the end");
+ auto &AccelSection = AccelTable->AccelSection;
+ if (Data >= NumData ||
+ !AccelSection.isValidOffsetForDataOfSize(DataOffset, 4)) {
+ NumData = 0;
+ return;
+ }
+ for (auto &Atom : AtomForms)
+ Atom.extractValue(AccelSection, &DataOffset, nullptr);
+ ++Data;
+}
+
+iterator_range<DWARFAcceleratorTable::ValueIterator>
+DWARFAcceleratorTable::equal_range(StringRef Key) const {
+ if (!IsValid)
+ return make_range(ValueIterator(), ValueIterator());
+
+ // Find the bucket.
+ unsigned HashValue = dwarf::djbHash(Key);
+ unsigned Bucket = HashValue % Hdr.NumBuckets;
+ unsigned BucketBase = sizeof(Hdr) + Hdr.HeaderDataLength;
+ unsigned HashesBase = BucketBase + Hdr.NumBuckets * 4;
+ unsigned OffsetsBase = HashesBase + Hdr.NumHashes * 4;
+
+ unsigned BucketOffset = BucketBase + Bucket * 4;
+ unsigned Index = AccelSection.getU32(&BucketOffset);
+
+ // Search through all hashes in the bucket.
+ for (unsigned HashIdx = Index; HashIdx < Hdr.NumHashes; ++HashIdx) {
+ unsigned HashOffset = HashesBase + HashIdx * 4;
+ unsigned OffsetsOffset = OffsetsBase + HashIdx * 4;
+ uint32_t Hash = AccelSection.getU32(&HashOffset);
+
+ if (Hash % Hdr.NumBuckets != Bucket)
+ // We are already in the next bucket.
+ break;
+
+ unsigned DataOffset = AccelSection.getU32(&OffsetsOffset);
+ unsigned StringOffset = AccelSection.getRelocatedValue(4, &DataOffset);
+ if (!StringOffset)
+ break;
+
+ // Finally, compare the key.
+ if (Key == StringSection.getCStr(&StringOffset))
+ return make_range({*this, DataOffset}, ValueIterator());
+ }
+ return make_range(ValueIterator(), ValueIterator());
+}