[PATCH] D147269: [DebugInfo] printCompactDWARFExpr: don't assert on stack size

[Scott Linder via Phabricator via llvm-commits]

scott.linder created this revision.
Herald added a subscriber: hiraditya.
Herald added a project: All.
scott.linder requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Gracefully handle non-1 stack sizes in printCompactDWARFExpr rather than
assert. Add support for DW_OP_nop and test the zero-sized stack case.

This is intended to be nearly NFC.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D147269

Files:
  llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
  llvm/unittests/DebugInfo/DWARF/DWARFExpressionCompactPrinterTest.cpp


Index: llvm/unittests/DebugInfo/DWARF/DWARFExpressionCompactPrinterTest.cpp
===================================================================
--- llvm/unittests/DebugInfo/DWARF/DWARFExpressionCompactPrinterTest.cpp
+++ llvm/unittests/DebugInfo/DWARF/DWARFExpressionCompactPrinterTest.cpp
@@ -124,3 +124,11 @@
       {DW_OP_entry_value, 0x02, DW_OP_breg13, 0x10, DW_OP_stack_value},
       "entry([SP+16])");
 }
+
+TEST_F(DWARFExpressionCompactPrinterTest, Test_OP_nop) {
+  TestExprPrinter({DW_OP_nop}, "<stack of size 0, expected 1>");
+}
+
+TEST_F(DWARFExpressionCompactPrinterTest, Test_OP_nop_OP_reg) {
+  TestExprPrinter({DW_OP_nop, DW_OP_reg0}, "R0");
+}
Index: llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
===================================================================
--- llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
+++ llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
@@ -451,6 +451,9 @@
       Stack.back().Kind = PrintedExpr::Value;
       break;
     }
+    case dwarf::DW_OP_nop: {
+      break;
+    }
     default:
       if (Opcode >= dwarf::DW_OP_reg0 && Opcode <= dwarf::DW_OP_reg31) {
         // DW_OP_reg<N>: A register, with the register num implied by the
@@ -484,7 +487,10 @@
     ++I;
   }
 
-  assert(Stack.size() == 1 && "expected one value on stack");
+  if (Stack.size() != 1) {
+    OS << "<stack of size " << Stack.size() << ", expected 1>";
+    return false;
+  }
 
   if (Stack.front().Kind == PrintedExpr::Address)
     OS << "[" << Stack.front().String << "]";


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D147269.509804.patch
Type: text/x-patch
Size: 1501 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230330/646ed5e1/attachment.bin>