[Lldb-commits] [PATCH] D147370: [lldb] fixing #61727 fixing incorrect variable displaying with DW_OP_div

[LU Hongyi via Phabricator via lldb-commits]

jwnhy created this revision.
jwnhy added reviewers: Michael137, DavidSpickett.
Herald added a project: All.
jwnhy requested review of this revision.
Herald added a project: LLDB.
Herald added a subscriber: lldb-commits.

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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D147370

Files:
  lldb/source/Expression/DWARFExpression.cpp


Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -1436,8 +1436,12 @@
           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.");



Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -1436,8 +1436,12 @@
           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.");

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