[dwarfdump] Fix off-by-one bug in accelerator table extractor.

This fixes a bug where the verifier was complaining about empty
accelerator tables. When the table is empty, its size is not a valid
offset as it points after the end of the section.

This patch also makes the extractor return llvm:Error instead of bool
for better error reporting in the verifier.

Differential revision: https://reviews.llvm.org/D41063

rdar://35932007

llvm-svn: 320399

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
index 8e07bb3c462..3d473698b46 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -686,8 +686,8 @@ unsigned DWARFVerifier::verifyAccelTable(const DWARFSection *AccelSection,
   }
 
   // Verify that the section is not too short.
-  if (!AccelTable.extract()) {
-    error() << "Section is smaller than size described in section header.\n";
+  if (Error E = AccelTable.extract()) {
+    error() << toString(std::move(E)) << '\n';
     return 1;
   }