[Lldb-commits] [lldb] Zero extend APInt when piece size is bigger than the bitwidth (PR #150149)

[satyanarayana reddy janga via lldb-commits]

https://github.com/satyajanga updated https://github.com/llvm/llvm-project/pull/150149

>From f4c7789bb5994f1df81294c054ddc74b397e6e3f Mon Sep 17 00:00:00 2001
From: satya janga <satyajanga at fb.com>
Date: Tue, 22 Jul 2025 17:57:30 -0700
Subject: [PATCH] Zero extend APInt when piece size is bigger than the bitwidth

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Differential Revision: https://phabricator.intern.facebook.com/D78791142
---
 lldb/source/Expression/DWARFExpression.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 52891fcefd68b..a709574e96f98 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -1978,7 +1978,12 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
             // grows to the nearest host integer type.
             llvm::APInt fail_value(1, 0, false);
             llvm::APInt ap_int = scalar.UInt128(fail_value);
-            assert(ap_int.getBitWidth() >= bit_size);
+            // We have seen a case where we have expression like:
+            //      DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x28
+            // here we are assuming the compiler was trying to zero
+            // extend the value that we should append to the buffer.
+            if (ap_int.getBitWidth() < bit_size)
+              ap_int.zext(bit_size);
             llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(),
                                          ap_int.getNumWords()};
             curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf));