1 files changed, 152 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/DWARFDebugAranges.cpp b/contrib/llvm/lib/DebugInfo/DWARFDebugAranges.cpp
new file mode 100644
index 0000000..591d4bd
--- /dev/null
+++ b/contrib/llvm/lib/DebugInfo/DWARFDebugAranges.cpp
@@ -0,0 +1,152 @@
+//===-- DWARFDebugAranges.cpp -----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFDebugAranges.h"
+#include "DWARFCompileUnit.h"
+#include "DWARFContext.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+using namespace llvm;
+
+void DWARFDebugAranges::extract(DataExtractor DebugArangesData) {
+  if (!DebugArangesData.isValidOffset(0))
+    return;
+  uint32_t Offset = 0;
+  typedef std::vector<DWARFDebugArangeSet> RangeSetColl;
+  RangeSetColl Sets;
+  DWARFDebugArangeSet Set;
+  uint32_t TotalRanges = 0;
+
+  while (Set.extract(DebugArangesData, &Offset)) {
+    Sets.push_back(Set);
+    TotalRanges += Set.getNumDescriptors();
+  }
+  if (TotalRanges == 0)
+    return;
+
+  Aranges.reserve(TotalRanges);
+  for (RangeSetColl::const_iterator I = Sets.begin(), E = Sets.end(); I != E;
+       ++I) {
+    uint32_t CUOffset = I->getCompileUnitDIEOffset();
+
+    for (uint32_t i = 0, n = I->getNumDescriptors(); i < n; ++i) {
+      const DWARFDebugArangeSet::Descriptor *ArangeDescPtr =
+          I->getDescriptor(i);
+      uint64_t LowPC = ArangeDescPtr->Address;
+      uint64_t HighPC = LowPC + ArangeDescPtr->Length;
+      appendRange(CUOffset, LowPC, HighPC);
+    }
+  }
+}
+
+void DWARFDebugAranges::generate(DWARFContext *CTX) {
+  clear();
+  if (!CTX)
+    return;
+
+  // Extract aranges from .debug_aranges section.
+  DataExtractor ArangesData(CTX->getARangeSection(), CTX->isLittleEndian(), 0);
+  extract(ArangesData);
+
+  // Generate aranges from DIEs: even if .debug_aranges section is present,
+  // it may describe only a small subset of compilation units, so we need to
+  // manually build aranges for the rest of them.
+  for (uint32_t i = 0, n = CTX->getNumCompileUnits(); i < n; ++i) {
+    if (DWARFCompileUnit *CU = CTX->getCompileUnitAtIndex(i)) {
+      uint32_t CUOffset = CU->getOffset();
+      if (ParsedCUOffsets.insert(CUOffset).second)
+        CU->buildAddressRangeTable(this, true, CUOffset);
+    }
+  }
+
+  sortAndMinimize();
+}
+
+void DWARFDebugAranges::appendRange(uint32_t CUOffset, uint64_t LowPC,
+                                    uint64_t HighPC) {
+  if (!Aranges.empty()) {
+    if (Aranges.back().CUOffset == CUOffset &&
+        Aranges.back().HighPC() == LowPC) {
+      Aranges.back().setHighPC(HighPC);
+      return;
+    }
+  }
+  Aranges.push_back(Range(LowPC, HighPC, CUOffset));
+}
+
+void DWARFDebugAranges::sortAndMinimize() {
+  const size_t orig_arange_size = Aranges.size();
+  // Size of one? If so, no sorting is needed
+  if (orig_arange_size <= 1)
+    return;
+  // Sort our address range entries
+  std::stable_sort(Aranges.begin(), Aranges.end());
+
+  // Most address ranges are contiguous from function to function
+  // so our new ranges will likely be smaller. We calculate the size
+  // of the new ranges since although std::vector objects can be resized,
+  // the will never reduce their allocated block size and free any excesss
+  // memory, so we might as well start a brand new collection so it is as
+  // small as possible.
+
+  // First calculate the size of the new minimal arange vector
+  // so we don't have to do a bunch of re-allocations as we
+  // copy the new minimal stuff over to the new collection.
+  size_t minimal_size = 1;
+  for (size_t i = 1; i < orig_arange_size; ++i) {
+    if (!Range::SortedOverlapCheck(Aranges[i-1], Aranges[i]))
+      ++minimal_size;
+  }
+
+  // If the sizes are the same, then no consecutive aranges can be
+  // combined, we are done.
+  if (minimal_size == orig_arange_size)
+    return;
+
+  // Else, make a new RangeColl that _only_ contains what we need.
+  RangeColl minimal_aranges;
+  minimal_aranges.resize(minimal_size);
+  uint32_t j = 0;
+  minimal_aranges[j] = Aranges[0];
+  for (size_t i = 1; i < orig_arange_size; ++i) {
+    if (Range::SortedOverlapCheck(minimal_aranges[j], Aranges[i])) {
+      minimal_aranges[j].setHighPC(Aranges[i].HighPC());
+    } else {
+      // Only increment j if we aren't merging
+      minimal_aranges[++j] = Aranges[i];
+    }
+  }
+  assert(j+1 == minimal_size);
+
+  // Now swap our new minimal aranges into place. The local
+  // minimal_aranges will then contian the old big collection
+  // which will get freed.
+  minimal_aranges.swap(Aranges);
+}
+
+uint32_t DWARFDebugAranges::findAddress(uint64_t Address) const {
+  if (!Aranges.empty()) {
+    Range range(Address);
+    RangeCollIterator begin = Aranges.begin();
+    RangeCollIterator end = Aranges.end();
+    RangeCollIterator pos =
+        std::lower_bound(begin, end, range);
+
+    if (pos != end && pos->containsAddress(Address)) {
+      return pos->CUOffset;
+    } else if (pos != begin) {
+      --pos;
+      if (pos->containsAddress(Address))
+        return pos->CUOffset;
+    }
+  }
+  return -1U;
+}