Revert "[IR] Remove the DIExpression field from DIGlobalVariable."

This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

llvm-svn: 289982

1 files changed, 9 insertions, 7 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 6b9bc689a44..7f91b49d828 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -53,12 +53,11 @@ void DebugInfoFinder::reset() {
 void DebugInfoFinder::processModule(const Module &M) {
   for (auto *CU : M.debug_compile_units()) {
     addCompileUnit(CU);
-    for (auto DIG : CU->getGlobalVariables()) {
-      if (!addGlobalVariable(DIG))
-        continue;
-      auto *GV = DIG->getVariable();
-      processScope(GV->getScope());
-      processType(GV->getType().resolve());
+    for (auto *DIG : CU->getGlobalVariables()) {
+      if (addGlobalVariable(DIG)) {
+        processScope(DIG->getScope());
+        processType(DIG->getType().resolve());
+      }
     }
     for (auto *ET : CU->getEnumTypes())
       processType(ET);
@@ -207,7 +206,10 @@ bool DebugInfoFinder::addCompileUnit(DICompileUnit *CU) {
   return true;
 }
 
-bool DebugInfoFinder::addGlobalVariable(DIGlobalVariableExpression *DIG) {
+bool DebugInfoFinder::addGlobalVariable(DIGlobalVariable *DIG) {
+  if (!DIG)
+    return false;
+
   if (!NodesSeen.insert(DIG).second)
     return false;