Commit e15d6b52 authored by LU Hongyi's avatar LU Hongyi Committed by Michael Buch
Browse files

[lldb][DWARFExpression] Fix DW_OP_div to use signed division 

This patch resolves an issue where a value
is incorrectly displayed if it is represented
by DW_OP_div.

This issue is caused by lldb evaluating
operands of DW_OP_div as unsigned
and performed unintended unsigned
division.

This issue is resolved by creating two
temporary signed scalar and performing
signed division.

(Addresses GH#61727)

Differential Revision: https://reviews.llvm.org/D147370
parent 2cdb6b84

lldb/source/Expression/DWARFExpression.cpp

+6 −2
Original line number Diff line number Diff line
@@ -1436,8 +1436,12 @@ bool DWARFExpression::Evaluate( 
          return false;

        } else {

          stack.pop_back();

          stack.back() =

              stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);

          Scalar divisor, dividend;

          divisor = tmp.ResolveValue(exe_ctx);

          dividend = stack.back().ResolveValue(exe_ctx);

          divisor.MakeSigned();

          dividend.MakeSigned();

          stack.back() = dividend / divisor;

          if (!stack.back().ResolveValue(exe_ctx).IsValid()) {

            if (error_ptr)

              error_ptr->SetErrorString("Divide failed.");

lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s

0 → 100644
+468 −0

File added.

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