[Lldb-commits] [lldb] [lldb] Reject mixed typed DWARF binary operands (PR #201288)
via lldb-commits
lldb-commits at lists.llvm.org
Wed Jun 3 01:06:43 PDT 2026
https://github.com/firmiana402 updated https://github.com/llvm/llvm-project/pull/201288
>From f1b02e03761213e92d2e782c0b367d9d56cd240a Mon Sep 17 00:00:00 2001
From: firmiana402 <firmiana402 at gmail.com>
Date: Wed, 3 Jun 2026 11:31:09 +0800
Subject: [PATCH] [lldb] Reject mixed typed DWARF binary operands
---
lldb/source/Expression/DWARFExpression.cpp | 90 ++++++++++++++++++++++
1 file changed, 90 insertions(+)
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 106e3b4d59283..c04fcc34b7dfa 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -1291,6 +1291,32 @@ static llvm::Error Evaluate_DW_OP_call_frame_cfa(EvalContext &eval_ctx) {
return llvm::Error::success();
}
+static llvm::Error CheckScalarOperandsHaveSameType(const Scalar &lhs,
+ const Scalar &rhs,
+ LocationAtom opcode) {
+ // Scalar does not preserve the original DWARF DIE, but it does carry the
+ // pieces of base-type information used by the evaluator: kind, size, and
+ // integer signedness.
+ if (lhs.GetType() != rhs.GetType())
+ return llvm::createStringError(
+ "%s requires operands to have the same type",
+ DW_OP_value_to_name(opcode));
+
+ if (lhs.GetByteSize() != rhs.GetByteSize())
+ return llvm::createStringError(
+ "%s requires operands to have the same type",
+ DW_OP_value_to_name(opcode));
+
+ // Floating scalars do not have integer signedness, so only compare
+ // signedness after establishing that both operands are integers.
+ if (lhs.GetType() == Scalar::e_int && lhs.IsSigned() != rhs.IsSigned())
+ return llvm::createStringError(
+ "%s requires operands to have the same type",
+ DW_OP_value_to_name(opcode));
+
+ return llvm::Error::success();
+}
+
llvm::Expected<Value> DWARFExpression::Evaluate(
ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
lldb::ModuleSP module_sp, const DataExtractor &opcodes,
@@ -1470,12 +1496,20 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
break;
case DW_OP_and:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() & tmp.GetScalar();
break;
case DW_OP_div: {
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
if (tmp.GetScalar().IsZero())
return llvm::createStringError("divide by zero");
@@ -1493,12 +1527,20 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
} break;
case DW_OP_minus:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() - tmp.GetScalar();
break;
case DW_OP_mod:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() % tmp.GetScalar();
@@ -1521,12 +1563,20 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
break;
case DW_OP_or:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() | tmp.GetScalar();
break;
case DW_OP_plus:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() += tmp.GetScalar();
@@ -1541,12 +1591,20 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
} break;
case DW_OP_shl:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() <<= tmp.GetScalar();
break;
case DW_OP_shr:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
if (!stack.back().GetScalar().ShiftRightLogical(tmp.GetScalar()))
@@ -1554,12 +1612,20 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
break;
case DW_OP_shra:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() >>= tmp.GetScalar();
break;
case DW_OP_xor:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() ^ tmp.GetScalar();
@@ -1601,36 +1667,60 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
} break;
case DW_OP_eq:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() == tmp.GetScalar();
break;
case DW_OP_ge:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() >= tmp.GetScalar();
break;
case DW_OP_gt:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() > tmp.GetScalar();
break;
case DW_OP_le:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() <= tmp.GetScalar();
break;
case DW_OP_lt:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() < tmp.GetScalar();
break;
case DW_OP_ne:
+ if (llvm::Error err = CheckScalarOperandsHaveSameType(
+ stack[stack.size() - 2].GetScalar(), stack.back().GetScalar(),
+ opcode))
+ return err;
tmp = stack.back();
stack.pop_back();
stack.back().GetScalar() = stack.back().GetScalar() != tmp.GetScalar();
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