[Lldb-commits] [lldb] [lldb] Allow division by floating point zero in Scalar (PR #158115)

[Ilia Kuklin via lldb-commits]

https://github.com/kuilpd created https://github.com/llvm/llvm-project/pull/158115

`Scalar` produced an invalid value when detecting any division by zero. This should be only for integer division.

>From 8cffb7a919d4ca4dc4421e24d8f19eb1d58d5523 Mon Sep 17 00:00:00 2001
From: Ilia Kuklin <ikuklin at accesssoftek.com>
Date: Thu, 11 Sep 2025 20:57:59 +0500
Subject: [PATCH] [lldb] Allow division by floating point zero in Scalar

---
 lldb/source/Utility/Scalar.cpp        | 5 +++--
 lldb/unittests/Utility/ScalarTest.cpp | 6 ++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Utility/Scalar.cpp b/lldb/source/Utility/Scalar.cpp
index 7fbe46d46194f..c8766bdf2aee7 100644
--- a/lldb/source/Utility/Scalar.cpp
+++ b/lldb/source/Utility/Scalar.cpp
@@ -565,12 +565,13 @@ const Scalar lldb_private::operator-(Scalar lhs, Scalar rhs) {
 
 const Scalar lldb_private::operator/(Scalar lhs, Scalar rhs) {
   Scalar result;
-  if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void &&
-      !rhs.IsZero()) {
+  if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
     switch (result.m_type) {
     case Scalar::e_void:
       break;
     case Scalar::e_int:
+      if (rhs.IsZero())
+        break;
       result.m_integer = lhs.m_integer / rhs.m_integer;
       return result;
     case Scalar::e_float:
diff --git a/lldb/unittests/Utility/ScalarTest.cpp b/lldb/unittests/Utility/ScalarTest.cpp
index 256d456783583..6d5caef42bee4 100644
--- a/lldb/unittests/Utility/ScalarTest.cpp
+++ b/lldb/unittests/Utility/ScalarTest.cpp
@@ -337,6 +337,12 @@ TEST(ScalarTest, Division) {
   Scalar r = lhs / rhs;
   EXPECT_TRUE(r.IsValid());
   EXPECT_EQ(r, Scalar(2.5));
+
+  Scalar inf = Scalar(1) / Scalar(0.0f);
+  Scalar int0 = Scalar(1) / Scalar(0);
+  Scalar ref_inf = llvm::APFloat::getInf(llvm::APFloat::IEEEsingle());
+  EXPECT_EQ(inf, ref_inf);
+  EXPECT_FALSE(int0.IsValid());
 }
 
 TEST(ScalarTest, Promotion) {