llvm-symbolizer: prefer .dwo contents over fission-gmlt-like-data when .dwo file is present

Rather than relying on the gmlt-like data emitted into the .o/executable
which only contains the simple name of any inlined functions, use the
.dwo file if present.

Test symbolication with/without a .dwo, and the old test that was
testing behavior when no gmlt-like data was present. (I haven't included
a test of non-gmlt-like data + no .dwo (that would be akin to
symbolication with no debug info) but we could add one for completeness)

The test was simplified a bit to be a little clearer (unoptimized, force
inline, using a function call as the inlined entity) and regenerated
with ToT clang. For the no-gmlt-like-data case, I modified Clang back to
its old behavior temporarily & the .dwo file is identical so it is
shared between the two executables.

llvm-svn: 267227

1 files changed, 7 insertions, 12 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index fdc9da3fbae..0430265ae74 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -378,19 +378,14 @@ DWARFUnit::getInlinedChainForAddress(uint64_t Address) {
   // First, find a subprogram that contains the given address (the root
   // of inlined chain).
   const DWARFUnit *ChainCU = nullptr;
-  const DWARFDebugInfoEntryMinimal *SubprogramDIE =
-      getSubprogramForAddress(Address);
-  if (SubprogramDIE) {
+  const DWARFDebugInfoEntryMinimal *SubprogramDIE;
+  // Try to look for subprogram DIEs in the DWO file.
+  parseDWO();
+  if (DWO) {
+    if ((SubprogramDIE = DWO->getUnit()->getSubprogramForAddress(Address)))
+      ChainCU = DWO->getUnit();
+  } else if ((SubprogramDIE = getSubprogramForAddress(Address)))
     ChainCU = this;
-  } else {
-    // Try to look for subprogram DIEs in the DWO file.
-    parseDWO();
-    if (DWO.get()) {
-      SubprogramDIE = DWO->getUnit()->getSubprogramForAddress(Address);
-      if (SubprogramDIE)
-        ChainCU = DWO->getUnit();
-    }
-  }
 
   // Get inlined chain rooted at this subprogram DIE.
   if (!SubprogramDIE)