commit e79dda31e9ed6cfc97d06ad87976fb16e53f3780
author David Blaikie <dblaikie@gmail.com> Tue Sep 19 18:36:11 2017 +0000
committer David Blaikie <dblaikie@gmail.com> Tue Sep 19 18:36:11 2017 +0000
tree 339ea31b04b0f23ff8c0bfd5f1c682696e91097e
parent b6e60c8b80704e948cf049569145ddf8497d7e05

dwarfdump/symbolizer: Avoid loading unneeded CUs from a DWP

When symbolizing large binaries, parsing every CU in a DWP file is a
significant performance penalty. Instead, use the index to only load the
CUs that are needed.

llvm-svn: 313659

llvm/lib/DebugInfo/DWARF/DWARFContext.cpp

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 90df9f4..0e28954 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -464,12 +464,11 @@
 }
 
 DWARFCompileUnit *DWARFContext::getDWOCompileUnitForHash(uint64_t Hash) {
-  parseDWOCompileUnits();
+  DWOCUs.parseDWO(*this, DObj->getInfoDWOSection(), true);
 
   if (const auto &CUI = getCUIndex()) {
     if (const auto *R = CUI.getFromHash(Hash))
-      if (auto CUOff = R->getOffset(DW_SECT_INFO))
-        return DWOCUs.getUnitForOffset(CUOff->Offset);
+      return DWOCUs.getUnitForIndexEntry(*R);
     return nullptr;
   }
 

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 4467b4a..86451fa 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -33,17 +33,17 @@
   const DWARFObject &D = C.getDWARFObj();
   parseImpl(C, Section, C.getDebugAbbrev(), &D.getRangeSection(),
             D.getStringSection(), D.getStringOffsetSection(),
-            &D.getAddrSection(), D.getLineSection(), D.isLittleEndian(), false);
+            &D.getAddrSection(), D.getLineSection(), D.isLittleEndian(), false,
+            false);
 }
 
 void DWARFUnitSectionBase::parseDWO(DWARFContext &C,
-                                    const DWARFSection &DWOSection,
-                                    DWARFUnitIndex *Index) {
+                                    const DWARFSection &DWOSection, bool Lazy) {
   const DWARFObject &D = C.getDWARFObj();
   parseImpl(C, DWOSection, C.getDebugAbbrevDWO(), &D.getRangeDWOSection(),
             D.getStringDWOSection(), D.getStringOffsetDWOSection(),
             &D.getAddrSection(), D.getLineDWOSection(), C.isLittleEndian(),
-            true);
+            true, Lazy);
 }
 
 DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section,

llvm/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
index 6e8cbca..17f1757 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
@@ -165,9 +165,12 @@
 const DWARFUnitIndex::Entry *
 DWARFUnitIndex::getFromOffset(uint32_t Offset) const {
   for (uint32_t i = 0; i != Header.NumBuckets; ++i)
-    if (const auto &Contribs = Rows[i].Contributions)
-      if (Contribs[InfoColumn].Offset == Offset)
+    if (const auto &Contribs = Rows[i].Contributions) {
+      const auto &InfoContrib = Contribs[InfoColumn];
+      if (InfoContrib.Offset <= Offset &&
+          Offset < (InfoContrib.Offset + InfoContrib.Length))
         return &Rows[i];
+    }
   return nullptr;
 }