Address review feedback

Changes:
- make the llvm-index-cache directory based off of %t to ensure uniqueness
- log to DWARF debug info channel when we fail to parse DWARFUnitHeaders

Author: clayborg

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp

@@ -24,6 +24,7 @@
 #include "DWARFDebugInfoEntry.h"
 #include "DWARFFormValue.h"
 #include "DWARFTypeUnit.h"
+#include "LogChannelDWARF.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -81,12 +82,14 @@ void DWARFDebugInfo::ParseUnitsFor(DIERef::Section section) {
                                 : m_context.getOrLoadDebugInfoData();
   lldb::offset_t offset = 0;
   while (data.ValidOffset(offset)) {
+    const lldb::offset_t unit_header_offset = offset;
     llvm::Expected<DWARFUnitSP> expected_unit_sp =
         DWARFUnit::extract(m_dwarf, m_units.size(), data, section, &offset);
 
     if (!expected_unit_sp) {
-      // FIXME: Propagate this error up.
-      llvm::consumeError(expected_unit_sp.takeError());
+      Log *log = GetLog(DWARFLog::DebugInfo);
+      LLDB_LOG(log, "Unable to extract DWARFUnitHeader at {0:x}: {1}",
+               unit_header_offset, llvm::toString(expected_unit_sp.takeError()));
       return;
     }
 

lldb/test/Shell/SymbolFile/DWARF/x86/dwp-separate-debug-file.cpp

@@ -11,10 +11,10 @@
 // Run one time with the index cache enabled to populate the index cache. When
 // we populate the index cache we have to parse all of the DWARF debug info
 // and it is always available.
-// RUN: rm -rf %T/lldb-index-cache
+// RUN: rm -rf %t.lldb-index-cache
 // RUN: %lldb \
 // RUN:   -O 'settings set symbols.enable-lldb-index-cache true' \
-// RUN:   -O 'settings set symbols.lldb-index-cache-path %T/lldb-index-cache' \
+// RUN:   -O 'settings set symbols.lldb-index-cache-path %t.lldb-index-cache' \
 // RUN:   -O 'settings set target.preload-symbols false' \
 // RUN:   -o "script lldb.target.modules[0].FindTypes('::A').GetTypeAtIndex(0)" \
 // RUN:   -o "statistics dump" \
@@ -28,7 +28,7 @@
 // don't crash and that we can find types when using .dwp files.
 // RUN: %lldb \
 // RUN:   -O 'settings set symbols.enable-lldb-index-cache true' \
-// RUN:   -O 'settings set symbols.lldb-index-cache-path %T/lldb-index-cache' \
+// RUN:   -O 'settings set symbols.lldb-index-cache-path %t.lldb-index-cache' \
 // RUN:   -O 'settings set target.preload-symbols false' \
 // RUN:   -o "script lldb.target.modules[0].FindTypes('::A').GetTypeAtIndex(0)" \
 // RUN:   -o "statistics dump" \
@@ -46,10 +46,10 @@
 // Run one time with the index cache enabled to populate the index cache. When
 // we populate the index cache we have to parse all of the DWARF debug info
 // and it is always available.
-// RUN: rm -rf %T/lldb-index-cache
+// RUN: rm -rf %t.lldb-index-cache
 // RUN: %lldb \
 // RUN:   -O 'settings set symbols.enable-lldb-index-cache true' \
-// RUN:   -O 'settings set symbols.lldb-index-cache-path %T/lldb-index-cache' \
+// RUN:   -O 'settings set symbols.lldb-index-cache-path %t.lldb-index-cache' \
 // RUN:   -O 'settings set target.preload-symbols false' \
 // RUN:   -o "script lldb.target.modules[0].FindTypes('::A').GetTypeAtIndex(0)" \
 // RUN:   -o "statistics dump" \
@@ -63,7 +63,7 @@
 // don't crash and that we can find types when using .dwp files.
 // RUN: %lldb \
 // RUN:   -O 'settings set symbols.enable-lldb-index-cache true' \
-// RUN:   -O 'settings set symbols.lldb-index-cache-path %T/lldb-index-cache' \
+// RUN:   -O 'settings set symbols.lldb-index-cache-path %t.lldb-index-cache' \
 // RUN:   -O 'settings set target.preload-symbols false' \
 // RUN:   -o "script lldb.target.modules[0].FindTypes('::A').GetTypeAtIndex(0)" \
 // RUN:   -o "statistics dump" \