[llvm] r300883 - Don't emit locations that need a DW_OP_stack_value in DWARF 2 & 3.

[Adrian Prantl via llvm-commits]

Author: adrian
Date: Thu Apr 20 15:42:33 2017
New Revision: 300883

URL: http://llvm.org/viewvc/llvm-project?rev=300883&view=rev
Log:
Don't emit locations that need a DW_OP_stack_value in DWARF 2 & 3.

https://bugs.llvm.org/show_bug.cgi?id=32382

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h
    llvm/trunk/test/DebugInfo/X86/dw_op_minus_direct.ll

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp?rev=300883&r1=300882&r2=300883&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp Thu Apr 20 15:42:33 2017
@@ -226,8 +226,15 @@ bool DwarfExpression::addMachineRegExpre
     return true;
   }
 
-  // FIXME:
   // Don't emit locations that cannot be expressed without DW_OP_stack_value.
+  if (DwarfVersion < 4)
+    if (std::any_of(ExprCursor.begin(), ExprCursor.end(),
+                    [](DIExpression::ExprOperand Op) -> bool {
+                      return Op.getOp() == dwarf::DW_OP_stack_value;
+                    })) {
+      DwarfRegs.clear();
+      return false;
+    }
 
   assert(DwarfRegs.size() == 1);
   auto Reg = DwarfRegs[0];

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h?rev=300883&r1=300882&r2=300883&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.h Thu Apr 20 15:42:33 2017
@@ -72,6 +72,8 @@ public:
   }
   /// Determine whether there are any operations left in this expression.
   operator bool() const { return Start != End; }
+  DIExpression::expr_op_iterator begin() const { return Start; }
+  DIExpression::expr_op_iterator end() const { return End; }
 
   /// Retrieve the fragment information, if any.
   Optional<DIExpression::FragmentInfo> getFragmentInfo() const {

Modified: llvm/trunk/test/DebugInfo/X86/dw_op_minus_direct.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/dw_op_minus_direct.ll?rev=300883&r1=300882&r2=300883&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/dw_op_minus_direct.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/dw_op_minus_direct.ll Thu Apr 20 15:42:33 2017
@@ -1,11 +1,20 @@
 ; Test dwarf codegen of DW_OP_minus.
 ; RUN: llc -filetype=obj < %s | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -dwarf-version=2 -filetype=obj < %s | llvm-dwarfdump - \
+; RUN:   | FileCheck %s --check-prefix=DWARF2
+; RUN: llc -dwarf-version=3 -filetype=obj < %s | llvm-dwarfdump - \
+; RUN:   | FileCheck %s --check-prefix=DWARF2
 
 ; This was derived manually from:
 ; int inc(int i) {
 ;  return i+1;
 ; }
 
+; DWARF2: .debug_info
+; DWARF2: DW_TAG_formal_parameter
+; DWARF2-NEXT: DW_AT_name {{.*}}"i"
+; DWARF2-NOT:  DW_AT_location
+
 ; CHECK: Beginning address offset: 0x0000000000000000
 ; CHECK:    Ending address offset: 0x0000000000000004
 ; CHECK:     Location description: 70 00 10 ff ff ff ff 0f 1a 10 01 1c 9f