Revert "[SafeStack][DebugInfo] Insert DW_OP_deref in correct location"

This reverts commit 2d3174c.

The overall solution for this problem is reverting D68945, which wasn't
handling the -O0 path through the codegen backend correctly. See:
discussion in D73526.

Author: jmorse

llvm/lib/CodeGen/LiveDebugVariables.cpp

@@ -650,8 +650,8 @@ bool LDVImpl::handleDebugValue(MachineInstr &MI, SlotIndex Idx) {
   }
 
   // Get or create the UserValue for (variable,offset) here.
-  assert((!MI.getOperand(1).isImm() || MI.getOperand(1).getImm() == 0) &&
-         "DBG_VALUE with nonzero offset");
+  assert(!MI.getOperand(1).isImm() && "DBG_VALUE with indirect flag before "
+                                      "LiveDebugVariables");
   const DILocalVariable *Var = MI.getDebugVariable();
   const DIExpression *Expr = MI.getDebugExpression();
   UserValue *UV =

llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp

@@ -751,9 +751,9 @@ InstrEmitter::EmitDbgValue(SDDbgValue *SD,
 
   // Indirect addressing is indicated by an Imm as the second parameter.
   if (SD->isIndirect())
-    MIB.addImm(0U);
-  else
-    MIB.addReg(0U, RegState::Debug);
+    Expr = DIExpression::append(Expr, {dwarf::DW_OP_deref});
+
+  MIB.addReg(0U, RegState::Debug);
 
   MIB.addMetadata(Var);
   MIB.addMetadata(Expr);

llvm/test/DebugInfo/COFF/types-array-advanced.ll

@@ -51,28 +51,39 @@
 ; CHECK:     SizeOf: 0
 ; CHECK:     Name: 
 ; CHECK:   }
-; CHECK:   Array (0x1004) {
+; CHECK:   Pointer (0x1004) {
+; CHECK:     TypeLeafKind: LF_POINTER (0x1002)
+; CHECK:     PointeeType: 0x1003
+; CHECK:     PtrType: Near32 (0xA)
+; CHECK:     PtrMode: LValueReference (0x1)
+; CHECK:     IsFlat: 0
+; CHECK:     IsConst: 0
+; CHECK:     IsVolatile: 0
+; CHECK:     IsUnaligned: 0
+; CHECK:     SizeOf: 0
+; CHECK:   }
+; CHECK:   Array (0x1005) {
 ; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)
 ; CHECK:     ElementType: char (0x70)
 ; CHECK:     IndexType: unsigned long (0x22)
 ; CHECK:     SizeOf: 7
 ; CHECK:     Name: 
 ; CHECK:   }
-; CHECK:   Array (0x1005) {
+; CHECK:   Array (0x1006) {
 ; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)
-; CHECK:     ElementType: 0x1004
+; CHECK:     ElementType: 0x1005
 ; CHECK:     IndexType: unsigned long (0x22)
 ; CHECK:     SizeOf: 35
 ; CHECK:     Name: 
 ; CHECK:   }
-; CHECK:   Array (0x1006) {
+; CHECK:   Array (0x1007) {
 ; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)
-; CHECK:     ElementType: 0x1005
+; CHECK:     ElementType: 0x1006
 ; CHECK:     IndexType: unsigned long (0x22)
 ; CHECK:     SizeOf: 70
 ; CHECK:     Name: 
 ; CHECK:   }
-; CHECK:   Struct (0x1007) {
+; CHECK:   Struct (0x1008) {
 ; CHECK:     TypeLeafKind: LF_STRUCTURE (0x1505)
 ; CHECK:     MemberCount: 0
 ; CHECK:     Properties [ (0x280)
@@ -86,16 +97,16 @@
 ; CHECK:     Name: incomplete_struct
 ; CHECK:     LinkageName: .?AUincomplete_struct@@
 ; CHECK:   }
-; CHECK:   Array (0x1008) {
+; CHECK:   Array (0x1009) {
 ; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)
-; CHECK:     ElementType: incomplete_struct (0x1007)
+; CHECK:     ElementType: incomplete_struct (0x1008)
 ; CHECK:     IndexType: unsigned long (0x22)
 ; CHECK:     SizeOf: 12
 ; CHECK:     Name: 
 ; CHECK:   }
-; CHECK:   Pointer (0x1009) {
+; CHECK:   Pointer (0x100A) {
 ; CHECK:     TypeLeafKind: LF_POINTER (0x1002)
-; CHECK:     PointeeType: 0x1008
+; CHECK:     PointeeType: 0x1009
 ; CHECK:     PtrType: Near32 (0xA)
 ; CHECK:     PtrMode: Pointer (0x0)
 ; CHECK:     IsFlat: 0
@@ -104,7 +115,7 @@
 ; CHECK:     IsUnaligned: 0
 ; CHECK:     SizeOf: 4
 ; CHECK:   }
-; CHECK:   FieldList (0x100A) {
+; CHECK:   FieldList (0x100B) {
 ; CHECK:     TypeLeafKind: LF_FIELDLIST (0x1203)
 ; CHECK:     DataMember {
 ; CHECK:       TypeLeafKind: LF_MEMBER (0x150D)
@@ -114,41 +125,41 @@
 ; CHECK:       Name: s1
 ; CHECK:     }
 ; CHECK:   }
-; CHECK:   Struct (0x100B) {
+; CHECK:   Struct (0x100C) {
 ; CHECK:     TypeLeafKind: LF_STRUCTURE (0x1505)
 ; CHECK:     MemberCount: 1
 ; CHECK:     Properties [ (0x200)
 ; CHECK:       HasUniqueName (0x200)
 ; CHECK:     ]
-; CHECK:     FieldList: <field list> (0x100A)
+; CHECK:     FieldList: <field list> (0x100B)
 ; CHECK:     DerivedFrom: 0x0
 ; CHECK:     VShape: 0x0
 ; CHECK:     SizeOf: 4
 ; CHECK:     Name: incomplete_struct
 ; CHECK:     LinkageName: .?AUincomplete_struct@@
 ; CHECK:   }
-; CHECK:   StringId (0x100C) {
+; CHECK:   StringId (0x100D) {
 ; CHECK:     TypeLeafKind: LF_STRING_ID (0x1605)
 ; CHECK:     Id: 0x0
 ; CHECK:     StringData: /t.cpp
 ; CHECK:   }
-; CHECK:   UdtSourceLine (0x100D) {
+; CHECK:   UdtSourceLine (0x100E) {
 ; CHECK:     TypeLeafKind: LF_UDT_SRC_LINE (0x1606)
-; CHECK:     UDT: incomplete_struct (0x100B)
-; CHECK:     SourceFile: /t.cpp (0x100C)
+; CHECK:     UDT: incomplete_struct (0x100C)
+; CHECK:     SourceFile: /t.cpp (0x100D)
 ; CHECK:     LineNumber: 4
 ; CHECK:   }
-; CHECK:   Modifier (0x100E) {
+; CHECK:   Modifier (0x100F) {
 ; CHECK:     TypeLeafKind: LF_MODIFIER (0x1001)
 ; CHECK:     ModifiedType: int (0x74)
 ; CHECK:     Modifiers [ (0x3)
 ; CHECK:       Const (0x1)
 ; CHECK:       Volatile (0x2)
 ; CHECK:     ]
 ; CHECK:   }
-; CHECK:   Array (0x100F) {
+; CHECK:   Array (0x1010) {
 ; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)
-; CHECK:     ElementType: const volatile int (0x100E)
+; CHECK:     ElementType: const volatile int (0x100F)
 ; CHECK:     IndexType: unsigned long (0x22)
 ; CHECK:     SizeOf: 16
 ; CHECK:     Name: 

llvm/test/DebugInfo/X86/safestack-byval.ll

@@ -14,7 +14,7 @@
 ; }
 
 ; CHECK: ![[ZZZ:.*]] = !DILocalVariable(name: "zzz",
-; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], !DIExpression(DW_OP_constu, 400, DW_OP_minus)
+; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], !DIExpression(DW_OP_constu, 400, DW_OP_minus, DW_OP_deref)
 
 %struct.S = type { [100 x i32] }