[llvm] r350010 - DebugInfo: Accurately propagate the section used by a relocation when accessing ranges defined by low/high_pc

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Sat Dec 22 14:20:40 2018
New Revision: 350010

URL: http://llvm.org/viewvc/llvm-project?rev=350010&view=rev
Log:
DebugInfo: Accurately propagate the section used by a relocation when accessing ranges defined by low/high_pc

This is difficult/not possible to test in LLVM, but is visible as a
crash in LLD when parsing DWARF to generate gdb-index.

This function is called by llvm-dwarfdump when parsing high_pc for
non-verbose output (to print the actual high_pc rather than the low_pc
relative value), but in that case llvm-dwarfdump doesn't print section
names (if it did, it would hit this problem).

We could add some other features to llvm-dwarfdump to expose this, but
nothing really springs to my mind. I will add a test to lld, though.

Modified:
    llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
    llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h?rev=350010&r1=350009&r2=350010&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFFormValue.h Sat Dec 22 14:20:40 2018
@@ -61,7 +61,6 @@ public:
 
   dwarf::Form getForm() const { return Form; }
   uint64_t getRawUValue() const { return Value.uval; }
-  uint64_t getSectionIndex() const { return Value.SectionIndex; }
   void setForm(dwarf::Form F) { Form = F; }
   void setUValue(uint64_t V) { Value.uval = V; }
   void setSValue(int64_t V) { Value.sval = V; }

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp?rev=350010&r1=350009&r2=350010&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp Sat Dec 22 14:20:40 2018
@@ -466,13 +466,13 @@ Optional<uint64_t> DWARFDie::getHighPC(u
 bool DWARFDie::getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
                                uint64_t &SectionIndex) const {
   auto F = find(DW_AT_low_pc);
-  auto LowPcAddr = toAddress(F);
+  auto LowPcAddr = toSectionedAddress(F);
   if (!LowPcAddr)
     return false;
-  if (auto HighPcAddr = getHighPC(*LowPcAddr)) {
-    LowPC = *LowPcAddr;
+  if (auto HighPcAddr = getHighPC(LowPcAddr->Address)) {
+    LowPC = LowPcAddr->Address;
     HighPC = *HighPcAddr;
-    SectionIndex = F->getSectionIndex();
+    SectionIndex = LowPcAddr->SectionIndex;
     return true;
   }
   return false;