[llvm] c75aac4 - [DWARF] Don't assume optional always has a value.

[Jonas Devlieghere via llvm-commits]

Author: Jonas Devlieghere
Date: 2020-01-03T09:53:44-08:00
New Revision: c75aac42a635bf710e818487592ea3bc5d7ef9b1

URL: https://github.com/llvm/llvm-project/commit/c75aac42a635bf710e818487592ea3bc5d7ef9b1
DIFF: https://github.com/llvm/llvm-project/commit/c75aac42a635bf710e818487592ea3bc5d7ef9b1.diff

LOG: [DWARF] Don't assume optional always has a value.

When getting the file name form the line table prologue we assume that a
valid string form value can always be extracted as a string. If you look
at the implementation of DWARFormValue this is not necessarily true. I
hit this assertion from LLDB when I create a "dummy" DWARFContext that
was missing the string section.

Added: 
    

Modified: 
    llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

Removed: 
    


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diff  --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
index 5c86858f31af..51535e88285b 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -1026,7 +1026,10 @@ bool DWARFDebugLine::Prologue::getFileNameByIndex(
   if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex))
     return false;
   const FileNameEntry &Entry = getFileNameEntry(FileIndex);
-  StringRef FileName = Entry.Name.getAsCString().getValue();
+  Optional<const char *> Name = Entry.Name.getAsCString();
+  if (!Name)
+    return false;
+  StringRef FileName = *Name;
   if (Kind != FileLineInfoKind::AbsoluteFilePath ||
       isPathAbsoluteOnWindowsOrPosix(FileName)) {
     Result = FileName;