[lld] r354972 - [DebugInfo] add SectionedAddress to DebugInfo interfaces.

[Alexey Lapshin via llvm-commits]

Author: avl
Date: Wed Feb 27 05:17:36 2019
New Revision: 354972

URL: http://llvm.org/viewvc/llvm-project?rev=354972&view=rev
Log:
[DebugInfo] add SectionedAddress to DebugInfo interfaces.

      That patch is the fix for https://bugs.llvm.org/show_bug.cgi?id=40703
   "wrong line number info for obj file compiled with -ffunction-sections"
   bug. The problem happened with only .o files. If object file contains
   several .text sections then line number information showed incorrectly.
   The reason for this is that DwarfLineTable could not detect section which
   corresponds to specified address(because address is the local to the
   section). And as the result it could not select proper sequence in the
   line table. The fix is to pass SectionIndex with the address. So that it
   would be possible to differentiate addresses from various sections. With
   this fix llvm-objdump shows correct line numbers for disassembled code.

   Differential review: https://reviews.llvm.org/D58194

Modified:
    lld/trunk/ELF/InputFiles.cpp

Modified: lld/trunk/ELF/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=354972&r1=354971&r2=354972&view=diff
==============================================================================
--- lld/trunk/ELF/InputFiles.cpp (original)
+++ lld/trunk/ELF/InputFiles.cpp Wed Feb 27 05:17:36 2019
@@ -205,14 +205,25 @@ Optional<DILineInfo> ObjFile<ELFT>::getD
                                                   uint64_t Offset) {
   llvm::call_once(InitDwarfLine, [this]() { initializeDwarf(); });
 
+  // Detect SectionIndex for specified section.
+  uint64_t SectionIndex = object::SectionedAddress::UndefSection;
+  ArrayRef<InputSectionBase *> Sections = S->File->getSections();
+  for (uint64_t CurIndex = 0; CurIndex < Sections.size(); ++CurIndex) {
+    if (S == Sections[CurIndex]) {
+      SectionIndex = CurIndex;
+      break;
+    }
+  }
+
   // Use fake address calcuated by adding section file offset and offset in
   // section. See comments for ObjectInfo class.
   DILineInfo Info;
-  for (const llvm::DWARFDebugLine::LineTable *LT : LineTables)
+  for (const llvm::DWARFDebugLine::LineTable *LT : LineTables) {
     if (LT->getFileLineInfoForAddress(
-            S->getOffsetInFile() + Offset, nullptr,
+            {S->getOffsetInFile() + Offset, SectionIndex}, nullptr,
             DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, Info))
       return Info;
+  }
   return None;
 }