From 603c97773331ac0249dd111897db2782d048c436 Mon Sep 17 00:00:00 2001
From: David Ockey <2897027+ockeydockey@users.noreply.github.com>
Date: Thu, 11 Sep 2025 10:23:50 -0500
Subject: [PATCH] Removed forced unsigned int cast in type_def bit-shift
 operators (#1178)

* Removed UB in type_def bit-shift operators

* Changed shift operators to allow both signed and unsigned operands for shifts
This allows the library user to explicitly use unsigned values to avoid UB

* Fixed constexpr errors for CPP11

* Changed is_arithmetic checks to use is_integral since valid shifts require integral operands

* Removed need for CPP11 since changes are CPP03 compatible
---
 include/etl/type_def.h | 33 +++++++++++++++++++++++++++++----
 test/test_type_def.cpp | 19 ++++++++++++++++---
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/include/etl/type_def.h b/include/etl/type_def.h
index 4815b670..30701932 100644
--- a/include/etl/type_def.h
+++ b/include/etl/type_def.h
@@ -290,14 +290,18 @@ namespace etl
     }
 
     //*********************************************************************
-    ETL_CONSTEXPR14 type_def& operator <<=(int rhs) ETL_NOEXCEPT
+    template <typename T>
+    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_integral<T>::value, type_def&>::type
+     operator <<=(T rhs) ETL_NOEXCEPT
     {
       value <<= rhs;
       return *this;
     }
 
     //*********************************************************************
-    ETL_CONSTEXPR14 type_def& operator >>=(int rhs) ETL_NOEXCEPT
+    template <typename T>
+    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_integral<T>::value, type_def&>::type
+     operator >>=(T rhs) ETL_NOEXCEPT
     {
       value >>= rhs;
       return *this;
@@ -589,19 +593,40 @@ namespace etl
     //*********************************************************************
     // << operator
     //*********************************************************************
-    friend ETL_CONSTEXPR type_def operator <<(const type_def& lhs, int rhs) ETL_NOEXCEPT
+    template <typename T>
+    friend ETL_CONSTEXPR typename etl::enable_if<etl::is_integral<T>::value, type_def>::type
+      operator <<(const type_def& lhs, T rhs) ETL_NOEXCEPT
     {
       return type_def(lhs.value << rhs);
     }
 
+    //*********************************************************************
+    template <typename T>
+    friend ETL_CONSTEXPR typename etl::enable_if<(etl::is_integral<T>::value && etl::is_integral<TValue>::value), T>::type
+      operator <<(T lhs, const type_def& rhs) ETL_NOEXCEPT
+    {
+      return lhs << rhs.value;
+    }
+
     //*********************************************************************
     // >> operator
     //*********************************************************************
-    friend ETL_CONSTEXPR type_def operator >>(const type_def& lhs, int rhs) ETL_NOEXCEPT
+    template <typename T>
+    friend ETL_CONSTEXPR typename etl::enable_if<etl::is_integral<T>::value, type_def>::type
+      operator >>(const type_def& lhs, T rhs) ETL_NOEXCEPT
     {
       return type_def(lhs.value >> rhs);
     }
 
+    //*********************************************************************
+    template <typename T>
+    friend ETL_CONSTEXPR
+    typename etl::enable_if<(etl::is_integral<T>::value && etl::is_integral<TValue>::value), T>::type
+      operator >>(T lhs, const type_def& rhs) ETL_NOEXCEPT
+    {
+      return lhs >> rhs.value;
+    }
+
     //*********************************************************************
     // < operator
     //*********************************************************************
diff --git a/test/test_type_def.cpp b/test/test_type_def.cpp
index 30d27772..facb2ed8 100644
--- a/test/test_type_def.cpp
+++ b/test/test_type_def.cpp
@@ -179,7 +179,9 @@ namespace
       CHECK_EQUAL(i |= 0x003DU, uint32_t(t |= type_t(0x003DU)));
       CHECK_EQUAL(i ^= 0xAA55U, uint32_t(t ^= 0xAA55U));
       CHECK_EQUAL(i ^= 0xAA55U, uint32_t(t ^= type_t(0xAA55U)));
+      CHECK_EQUAL(i <<= 2, uint32_t(t <<= 2));
       CHECK_EQUAL(i <<= 2U, uint32_t(t <<= 2U));
+      CHECK_EQUAL(i >>= 2, uint32_t(t >>= 2));
       CHECK_EQUAL(i >>= 2U, uint32_t(t >>= 2U));
       CHECK_EQUAL(i %= 23, uint32_t(t %= 23));
 
@@ -195,8 +197,10 @@ namespace
       
       uint32_t i1 = 0x5A3DUL;
       uint32_t i2 = 0xB47AUL;
+      uint32_t i3 = 3UL;
       type_t t1(0x5A3DUL);
       type_t t2(0xB47AUL);
+      type_t t3(3UL);
 
       CHECK_EQUAL(i1 + Two, t1 + Two);
       CHECK_EQUAL(Two + i1, Two + t1);
@@ -205,11 +209,11 @@ namespace
       CHECK_EQUAL(i1 - Two, t1 - Two);
       CHECK_EQUAL(i2 - i1, i2 - t1);
       CHECK_EQUAL(i2 - i1, t2 - t1);
-      
+
       CHECK_EQUAL(i1 * Two, t1 * Two);
       CHECK_EQUAL(Two * i1, Two * t1);
       CHECK_EQUAL(i1 * i2, t1 * t2);
-      
+
       CHECK_EQUAL(i1 / Two, t1 / Two);
       CHECK_EQUAL(i2  / i1, i2 / t1);
       CHECK_EQUAL(i2  / i1, t2 / t1);
@@ -227,7 +231,16 @@ namespace
       CHECK_EQUAL(uint32_t(0xAA55) ^ i1, type_t(0xAA55UL) ^ t1);
 
       CHECK_EQUAL(i1 << 2, t1 << 2);
+      CHECK_EQUAL(i1 << 2U, t1 << 2U);
+      CHECK_EQUAL(2 << i3, 2 << t3);
+      CHECK_EQUAL(2U << i3, 2U << t3);
+      CHECK_EQUAL(i1 << i3, t1 << t3);
+
       CHECK_EQUAL(i1 >> 2, t1 >> 2);
+      CHECK_EQUAL(i1 >> 2U, t1 >> 2U);
+      CHECK_EQUAL(42 >> i3, 42 >> t3);
+      CHECK_EQUAL(42U >> i3, 42U >> t3);
+      CHECK_EQUAL(i1 >> i3, t1 >> t3);
 
       CHECK_EQUAL(i1 % uint32_t(23), t1 % uint32_t(23));
       CHECK_EQUAL(uint32_t(23) % i1, uint32_t(23) % t1);
@@ -313,7 +326,7 @@ namespace
 
       return value;
     }
-    
+
     TEST(test_arithmetic_constexpr)
     {
       constexpr arithmetic_type_t value_plus  = CreatePlus();