From 8f81b4e7dcef93295bb1f486f12cdb4bf2bc9a03 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 27 Oct 2024 14:50:03 +0000
Subject: [PATCH 01/13] EssentialTypes: Correct handling of bitwise binary
 expressions

They shouldn't have the standard type if either both the operands
are signed or they are both unsigned.
---
 .../c/misra/EssentialTypes.qll                |  49 +++-
 c/misra/test/c/misra/EssentialTypes.expected  | 275 ++++++++++++++++++
 c/misra/test/c/misra/test.c                   |  80 +++++
 3 files changed, 402 insertions(+), 2 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 4783547ed2..4dbe8dbb34 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -192,8 +192,8 @@ class EssentialEqualityOperationExpr extends EssentialExpr, EqualityOperation {
   override Type getEssentialType() { result instanceof BoolType }
 }
 
-class EssentialBinaryBitwiseOperationExpr extends EssentialExpr, BinaryBitwiseOperation {
-  EssentialBinaryBitwiseOperationExpr() {
+class EssentialShiftOperationExpr extends EssentialExpr, BinaryBitwiseOperation {
+  EssentialShiftOperationExpr() {
     this instanceof LShiftExpr or
     this instanceof RShiftExpr
   }
@@ -353,6 +353,51 @@ class EssentialBinaryArithmeticExpr extends EssentialExpr, BinaryArithmeticOpera
   }
 }
 
+class EssentialBinaryBitwiseExpr extends EssentialExpr, BinaryBitwiseOperation {
+  EssentialBinaryBitwiseExpr() {
+    not this instanceof LShiftExpr and
+    not this instanceof RShiftExpr
+  }
+
+  override Type getEssentialType() {
+    exists(
+      Type leftEssentialType, Type rightEssentialType,
+      EssentialTypeCategory leftEssentialTypeCategory,
+      EssentialTypeCategory rightEssentialTypeCategory
+    |
+      leftEssentialType = getEssentialType(getLeftOperand()) and
+      rightEssentialType = getEssentialType(getRightOperand()) and
+      leftEssentialTypeCategory = getEssentialTypeCategory(leftEssentialType) and
+      rightEssentialTypeCategory = getEssentialTypeCategory(rightEssentialType)
+    |
+      if
+        leftEssentialTypeCategory = EssentiallySignedType() and
+        rightEssentialTypeCategory = EssentiallySignedType()
+      then
+        if exists(getValue())
+        then result = stlr(this)
+        else (
+          if leftEssentialType.getSize() > rightEssentialType.getSize()
+          then result = leftEssentialType
+          else result = rightEssentialType
+        )
+      else
+        if
+          leftEssentialTypeCategory = EssentiallyUnsignedType() and
+          rightEssentialTypeCategory = EssentiallyUnsignedType()
+        then
+          if exists(getValue())
+          then result = utlr(this)
+          else (
+            if leftEssentialType.getSize() > rightEssentialType.getSize()
+            then result = leftEssentialType
+            else result = rightEssentialType
+          )
+        else result = this.getStandardType()
+    )
+  }
+}
+
 /**
  * A named Enum type, as per D.5.
  */
diff --git a/c/misra/test/c/misra/EssentialTypes.expected b/c/misra/test/c/misra/EssentialTypes.expected
index c0e010b8e4..19a7090fe9 100644
--- a/c/misra/test/c/misra/EssentialTypes.expected
+++ b/c/misra/test/c/misra/EssentialTypes.expected
@@ -90,3 +90,278 @@
 | test.c:79:3:79:5 | 97 | char | char | essentially Character type |
 | test.c:80:3:80:6 | 10 | char | char | essentially Character type |
 | test.c:81:3:81:6 | 0 | char | char | essentially Character type |
+| test.c:87:16:87:16 | 0 | signed char | signed char | essentially Signed type |
+| test.c:87:16:87:16 | (uint8_t)... | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:88:18:88:18 | 0 | signed char | signed char | essentially Signed type |
+| test.c:88:18:88:18 | (uint16_t)... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:89:18:89:18 | 0 | signed char | signed char | essentially Signed type |
+| test.c:89:18:89:18 | (uint32_t)... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:90:15:90:15 | 0 | signed char | signed char | essentially Signed type |
+| test.c:90:15:90:15 | (int8_t)... | int8_t | int8_t | essentially Signed type |
+| test.c:91:17:91:17 | 0 | signed char | signed char | essentially Signed type |
+| test.c:91:17:91:17 | (int16_t)... | int16_t | int16_t | essentially Signed type |
+| test.c:92:16:92:17 | 0 | signed char | signed char | essentially Signed type |
+| test.c:94:3:94:4 | (int)... | int | int | essentially Signed type |
+| test.c:94:3:94:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:94:3:94:9 | ... & ... | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:94:8:94:9 | (int)... | int | int | essentially Signed type |
+| test.c:94:8:94:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:95:3:95:5 | (int)... | int | int | essentially Signed type |
+| test.c:95:3:95:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:95:3:95:10 | ... & ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:95:9:95:10 | (int)... | int | int | essentially Signed type |
+| test.c:95:9:95:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:96:3:96:4 | (int)... | int | int | essentially Signed type |
+| test.c:96:3:96:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:96:3:96:10 | ... & ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:96:8:96:10 | (int)... | int | int | essentially Signed type |
+| test.c:96:8:96:10 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:97:3:97:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:97:3:97:10 | ... & ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:97:9:97:10 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:97:9:97:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:98:3:98:4 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:98:3:98:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:98:3:98:10 | ... & ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:98:8:98:10 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:99:3:99:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:99:3:99:11 | ... & ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:99:9:99:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:99:9:99:11 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:100:3:100:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:100:3:100:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:100:3:100:11 | ... & ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:100:9:100:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:102:3:102:4 | (int)... | int | int | essentially Signed type |
+| test.c:102:3:102:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:102:3:102:9 | ... \| ... | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:102:8:102:9 | (int)... | int | int | essentially Signed type |
+| test.c:102:8:102:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:103:3:103:5 | (int)... | int | int | essentially Signed type |
+| test.c:103:3:103:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:103:3:103:10 | ... \| ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:103:9:103:10 | (int)... | int | int | essentially Signed type |
+| test.c:103:9:103:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:104:3:104:4 | (int)... | int | int | essentially Signed type |
+| test.c:104:3:104:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:104:3:104:10 | ... \| ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:104:8:104:10 | (int)... | int | int | essentially Signed type |
+| test.c:104:8:104:10 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:105:3:105:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:105:3:105:10 | ... \| ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:105:9:105:10 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:105:9:105:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:106:3:106:4 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:106:3:106:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:106:3:106:10 | ... \| ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:106:8:106:10 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:107:3:107:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:107:3:107:11 | ... \| ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:107:9:107:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:107:9:107:11 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:108:3:108:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:108:3:108:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:108:3:108:11 | ... \| ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:108:9:108:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:110:3:110:4 | (int)... | int | int | essentially Signed type |
+| test.c:110:3:110:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:110:3:110:9 | ... ^ ... | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:110:8:110:9 | (int)... | int | int | essentially Signed type |
+| test.c:110:8:110:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:111:3:111:5 | (int)... | int | int | essentially Signed type |
+| test.c:111:3:111:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:111:3:111:10 | ... ^ ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:111:9:111:10 | (int)... | int | int | essentially Signed type |
+| test.c:111:9:111:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:112:3:112:4 | (int)... | int | int | essentially Signed type |
+| test.c:112:3:112:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:112:3:112:10 | ... ^ ... | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:112:8:112:10 | (int)... | int | int | essentially Signed type |
+| test.c:112:8:112:10 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:113:3:113:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:113:3:113:10 | ... ^ ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:113:9:113:10 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:113:9:113:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:114:3:114:4 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:114:3:114:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:114:3:114:10 | ... ^ ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:114:8:114:10 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:115:3:115:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:115:3:115:11 | ... ^ ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:115:9:115:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:115:9:115:11 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:116:3:116:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:116:3:116:5 | u16 | uint16_t | uint16_t | essentially Unsigned type |
+| test.c:116:3:116:11 | ... ^ ... | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:116:9:116:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:118:3:118:4 | (int)... | int | int | essentially Signed type |
+| test.c:118:3:118:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:118:3:118:9 | ... & ... | int8_t | int8_t | essentially Signed type |
+| test.c:118:8:118:9 | (int)... | int | int | essentially Signed type |
+| test.c:118:8:118:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:119:3:119:5 | (int)... | int | int | essentially Signed type |
+| test.c:119:3:119:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:119:3:119:10 | ... & ... | int16_t | int16_t | essentially Signed type |
+| test.c:119:9:119:10 | (int)... | int | int | essentially Signed type |
+| test.c:119:9:119:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:120:3:120:4 | (int)... | int | int | essentially Signed type |
+| test.c:120:3:120:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:120:3:120:10 | ... & ... | int16_t | int16_t | essentially Signed type |
+| test.c:120:8:120:10 | (int)... | int | int | essentially Signed type |
+| test.c:120:8:120:10 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:121:3:121:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:121:3:121:10 | ... & ... | int32_t | int32_t | essentially Signed type |
+| test.c:121:9:121:10 | (int)... | int | int | essentially Signed type |
+| test.c:121:9:121:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:122:3:122:4 | (int)... | int | int | essentially Signed type |
+| test.c:122:3:122:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:122:3:122:10 | ... & ... | int32_t | int32_t | essentially Signed type |
+| test.c:122:8:122:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:123:3:123:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:123:3:123:11 | ... & ... | int32_t | int32_t | essentially Signed type |
+| test.c:123:9:123:11 | (int)... | int | int | essentially Signed type |
+| test.c:123:9:123:11 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:124:3:124:5 | (int)... | int | int | essentially Signed type |
+| test.c:124:3:124:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:124:3:124:11 | ... & ... | int32_t | int32_t | essentially Signed type |
+| test.c:124:9:124:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:126:3:126:4 | (int)... | int | int | essentially Signed type |
+| test.c:126:3:126:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:126:3:126:9 | ... \| ... | int8_t | int8_t | essentially Signed type |
+| test.c:126:8:126:9 | (int)... | int | int | essentially Signed type |
+| test.c:126:8:126:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:127:3:127:5 | (int)... | int | int | essentially Signed type |
+| test.c:127:3:127:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:127:3:127:10 | ... \| ... | int16_t | int16_t | essentially Signed type |
+| test.c:127:9:127:10 | (int)... | int | int | essentially Signed type |
+| test.c:127:9:127:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:128:3:128:4 | (int)... | int | int | essentially Signed type |
+| test.c:128:3:128:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:128:3:128:10 | ... \| ... | int16_t | int16_t | essentially Signed type |
+| test.c:128:8:128:10 | (int)... | int | int | essentially Signed type |
+| test.c:128:8:128:10 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:129:3:129:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:129:3:129:10 | ... \| ... | int32_t | int32_t | essentially Signed type |
+| test.c:129:9:129:10 | (int)... | int | int | essentially Signed type |
+| test.c:129:9:129:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:130:3:130:4 | (int)... | int | int | essentially Signed type |
+| test.c:130:3:130:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:130:3:130:10 | ... \| ... | int32_t | int32_t | essentially Signed type |
+| test.c:130:8:130:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:131:3:131:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:131:3:131:11 | ... \| ... | int32_t | int32_t | essentially Signed type |
+| test.c:131:9:131:11 | (int)... | int | int | essentially Signed type |
+| test.c:131:9:131:11 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:132:3:132:5 | (int)... | int | int | essentially Signed type |
+| test.c:132:3:132:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:132:3:132:11 | ... \| ... | int32_t | int32_t | essentially Signed type |
+| test.c:132:9:132:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:134:3:134:4 | (int)... | int | int | essentially Signed type |
+| test.c:134:3:134:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:134:3:134:9 | ... ^ ... | int8_t | int8_t | essentially Signed type |
+| test.c:134:8:134:9 | (int)... | int | int | essentially Signed type |
+| test.c:134:8:134:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:135:3:135:5 | (int)... | int | int | essentially Signed type |
+| test.c:135:3:135:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:135:3:135:10 | ... ^ ... | int16_t | int16_t | essentially Signed type |
+| test.c:135:9:135:10 | (int)... | int | int | essentially Signed type |
+| test.c:135:9:135:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:136:3:136:4 | (int)... | int | int | essentially Signed type |
+| test.c:136:3:136:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:136:3:136:10 | ... ^ ... | int16_t | int16_t | essentially Signed type |
+| test.c:136:8:136:10 | (int)... | int | int | essentially Signed type |
+| test.c:136:8:136:10 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:137:3:137:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:137:3:137:10 | ... ^ ... | int32_t | int32_t | essentially Signed type |
+| test.c:137:9:137:10 | (int)... | int | int | essentially Signed type |
+| test.c:137:9:137:10 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:138:3:138:4 | (int)... | int | int | essentially Signed type |
+| test.c:138:3:138:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:138:3:138:10 | ... ^ ... | int32_t | int32_t | essentially Signed type |
+| test.c:138:8:138:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:139:3:139:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:139:3:139:11 | ... ^ ... | int32_t | int32_t | essentially Signed type |
+| test.c:139:9:139:11 | (int)... | int | int | essentially Signed type |
+| test.c:139:9:139:11 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:140:3:140:5 | (int)... | int | int | essentially Signed type |
+| test.c:140:3:140:5 | s16 | int16_t | int16_t | essentially Signed type |
+| test.c:140:3:140:11 | ... ^ ... | int32_t | int32_t | essentially Signed type |
+| test.c:140:9:140:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:142:3:142:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:142:3:142:11 | ... & ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:142:9:142:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:142:9:142:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:143:3:143:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:143:3:143:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:143:3:143:11 | ... & ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:143:9:143:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:144:3:144:4 | (int)... | int | int | essentially Signed type |
+| test.c:144:3:144:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:144:3:144:10 | ... & ... | int | int | essentially Signed type |
+| test.c:144:8:144:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:145:3:145:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:145:3:145:10 | ... & ... | int | int | essentially Signed type |
+| test.c:145:9:145:10 | (int)... | int | int | essentially Signed type |
+| test.c:145:9:145:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:146:3:146:4 | (int)... | int | int | essentially Signed type |
+| test.c:146:3:146:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:146:3:146:9 | ... & ... | int | int | essentially Signed type |
+| test.c:146:8:146:9 | (int)... | int | int | essentially Signed type |
+| test.c:146:8:146:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:147:3:147:4 | (int)... | int | int | essentially Signed type |
+| test.c:147:3:147:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:147:3:147:9 | ... & ... | int | int | essentially Signed type |
+| test.c:147:8:147:9 | (int)... | int | int | essentially Signed type |
+| test.c:147:8:147:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:149:3:149:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:149:3:149:11 | ... \| ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:149:9:149:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:149:9:149:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:150:3:150:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:150:3:150:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:150:3:150:11 | ... \| ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:150:9:150:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:151:3:151:4 | (int)... | int | int | essentially Signed type |
+| test.c:151:3:151:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:151:3:151:10 | ... \| ... | int | int | essentially Signed type |
+| test.c:151:8:151:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:152:3:152:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:152:3:152:10 | ... \| ... | int | int | essentially Signed type |
+| test.c:152:9:152:10 | (int)... | int | int | essentially Signed type |
+| test.c:152:9:152:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:153:3:153:4 | (int)... | int | int | essentially Signed type |
+| test.c:153:3:153:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:153:3:153:9 | ... \| ... | int | int | essentially Signed type |
+| test.c:153:8:153:9 | (int)... | int | int | essentially Signed type |
+| test.c:153:8:153:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:154:3:154:4 | (int)... | int | int | essentially Signed type |
+| test.c:154:3:154:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:154:3:154:9 | ... \| ... | int | int | essentially Signed type |
+| test.c:154:8:154:9 | (int)... | int | int | essentially Signed type |
+| test.c:154:8:154:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:156:3:156:5 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:156:3:156:11 | ... ^ ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:156:9:156:11 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:156:9:156:11 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:157:3:157:5 | (unsigned int)... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:157:3:157:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:157:3:157:11 | ... ^ ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:157:9:157:11 | u32 | uint32_t | uint32_t | essentially Unsigned type |
+| test.c:158:3:158:4 | (int)... | int | int | essentially Signed type |
+| test.c:158:3:158:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:158:3:158:10 | ... ^ ... | int | int | essentially Signed type |
+| test.c:158:8:158:10 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:159:3:159:5 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:159:3:159:10 | ... ^ ... | int | int | essentially Signed type |
+| test.c:159:9:159:10 | (int)... | int | int | essentially Signed type |
+| test.c:159:9:159:10 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:160:3:160:4 | (int)... | int | int | essentially Signed type |
+| test.c:160:3:160:4 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:160:3:160:9 | ... ^ ... | int | int | essentially Signed type |
+| test.c:160:8:160:9 | (int)... | int | int | essentially Signed type |
+| test.c:160:8:160:9 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:161:3:161:4 | (int)... | int | int | essentially Signed type |
+| test.c:161:3:161:4 | s8 | int8_t | int8_t | essentially Signed type |
+| test.c:161:3:161:9 | ... ^ ... | int | int | essentially Signed type |
+| test.c:161:8:161:9 | (int)... | int | int | essentially Signed type |
+| test.c:161:8:161:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
diff --git a/c/misra/test/c/misra/test.c b/c/misra/test/c/misra/test.c
index b3fdddd591..dcdfef4eb4 100644
--- a/c/misra/test/c/misra/test.c
+++ b/c/misra/test/c/misra/test.c
@@ -79,4 +79,84 @@ void testControlChar() {
   'a';  // Essentially char
   '\n'; // Essentially char
   '\0'; // Essentially char
+}
+
+#include <stdint.h>
+
+void testBitwise() {
+  uint8_t u8 = 0;
+  uint16_t u16 = 0;
+  uint32_t u32 = 0;
+  int8_t s8 = 0;
+  int16_t s16 = 0;
+  int32_t s32 = 0;
+
+  u8 & u8;   // Essentially unsigned, char
+  u16 & u8;  // Essentially unsigned, short
+  u8 & u16;  // Essentially unsigned, short
+  u32 & u8;  // Essentially unsigned, int
+  u8 & u32;  // Essentially unsigned, int
+  u32 & u16; // Essentially unsigned, int
+  u16 & u32; // Essentially unsigned, int
+
+  u8 | u8;   // Essentially unsigned, char
+  u16 | u8;  // Essentially unsigned, short
+  u8 | u16;  // Essentially unsigned, short
+  u32 | u8;  // Essentially unsigned, int
+  u8 | u32;  // Essentially unsigned, int
+  u32 | u16; // Essentially unsigned, int
+  u16 | u32; // Essentially unsigned, int
+
+  u8 ^ u8;   // Essentially unsigned, char
+  u16 ^ u8;  // Essentially unsigned, short
+  u8 ^ u16;  // Essentially unsigned, short
+  u32 ^ u8;  // Essentially unsigned, int
+  u8 ^ u32;  // Essentially unsigned, int
+  u32 ^ u16; // Essentially unsigned, int
+  u16 ^ u32; // Essentially unsigned, int
+
+  s8 & s8;   // Essentially signed, char
+  s16 & s8;  // Essentially signed, short
+  s8 & s16;  // Essentially signed, short
+  s32 & s8;  // Essentially signed, int
+  s8 & s32;  // Essentially signed, int
+  s32 & s16; // Essentially signed, int
+  s16 & s32; // Essentially signed, int
+
+  s8 | s8;   // Essentially signed, char
+  s16 | s8;  // Essentially signed, short
+  s8 | s16;  // Essentially signed, short
+  s32 | s8;  // Essentially signed, int
+  s8 | s32;  // Essentially signed, int
+  s32 | s16; // Essentially signed, int
+  s16 | s32; // Essentially signed, int
+
+  s8 ^ s8;   // Essentially signed, char
+  s16 ^ s8;  // Essentially signed, short
+  s8 ^ s16;  // Essentially signed, short
+  s32 ^ s8;  // Essentially signed, int
+  s8 ^ s32;  // Essentially signed, int
+  s32 ^ s16; // Essentially signed, int
+  s16 ^ s32; // Essentially signed, int
+
+  u32 & s32; // Essentially signed, int
+  s32 & u32; // Essentially signed, int
+  u8 & s32;  // Essentially signed, int
+  s32 & u8;  // Essentially signed, int
+  u8 & s8;   // Essentially signed, int
+  s8 & u8;   // Essentially signed, int
+
+  u32 | s32; // Essentially signed, int
+  s32 | u32; // Essentially signed, int
+  u8 | s32;  // Essentially signed, int
+  s32 | u8;  // Essentially signed, int
+  u8 | s8;   // Essentially signed, int
+  s8 | u8;   // Essentially signed, int
+
+  u32 ^ s32; // Essentially signed, int
+  s32 ^ u32; // Essentially signed, int
+  u8 ^ s32;  // Essentially signed, int
+  s32 ^ u8;  // Essentially signed, int
+  u8 ^ s8;   // Essentially signed, int
+  s8 ^ u8;   // Essentially signed, int
 }
\ No newline at end of file

From a5ed461557c57b44df2f6a420e6ecc1bd89cbed2 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 27 Oct 2024 15:28:27 +0000
Subject: [PATCH 02/13] EssentialTypes: Add test cases for shifts

---
 c/misra/test/c/misra/EssentialTypes.expected | 73 ++++++++++++++++++++
 c/misra/test/c/misra/test.c                  | 38 ++++++++++
 2 files changed, 111 insertions(+)

diff --git a/c/misra/test/c/misra/EssentialTypes.expected b/c/misra/test/c/misra/EssentialTypes.expected
index 19a7090fe9..95976fe2ab 100644
--- a/c/misra/test/c/misra/EssentialTypes.expected
+++ b/c/misra/test/c/misra/EssentialTypes.expected
@@ -365,3 +365,76 @@
 | test.c:161:3:161:9 | ... ^ ... | int | int | essentially Signed type |
 | test.c:161:8:161:9 | (int)... | int | int | essentially Signed type |
 | test.c:161:8:161:9 | u8 | uint8_t | uint8_t | essentially Unsigned type |
+| test.c:165:16:165:17 | 1 | signed char | signed char | essentially Signed type |
+| test.c:170:3:170:4 | 1 | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:170:3:170:9 | ... << ... | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:170:9:170:9 | 1 | signed char | signed char | essentially Signed type |
+| test.c:171:3:171:6 | 256 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:171:3:171:11 | ... << ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:171:11:171:11 | 1 | signed char | signed char | essentially Signed type |
+| test.c:172:3:172:8 | 65536 | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:172:3:172:13 | ... << ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:172:13:172:13 | 1 | signed char | signed char | essentially Signed type |
+| test.c:173:3:173:4 | 2 | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:173:3:173:9 | ... >> ... | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:173:9:173:9 | 1 | signed char | signed char | essentially Signed type |
+| test.c:174:3:174:8 | 32768 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:174:3:174:13 | ... >> ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:174:13:174:13 | 1 | signed char | signed char | essentially Signed type |
+| test.c:175:3:175:13 | 2147483648 | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:175:3:175:18 | ... >> ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:175:18:175:18 | 1 | signed char | signed char | essentially Signed type |
+| test.c:176:3:176:14 | 4294967295 | unsigned long | unsigned long | essentially Unsigned type |
+| test.c:176:3:176:19 | ... << ... | unsigned long | unsigned long | essentially Unsigned type |
+| test.c:176:3:176:19 | ... << ... | unsigned long | unsigned long long | essentially Unsigned type |
+| test.c:176:3:176:19 | ... << ... | unsigned long long | unsigned long | essentially Unsigned type |
+| test.c:176:3:176:19 | ... << ... | unsigned long long | unsigned long long | essentially Unsigned type |
+| test.c:176:19:176:19 | 1 | signed char | signed char | essentially Signed type |
+| test.c:181:3:181:6 | 256 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:181:3:181:11 | ... >> ... | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:181:11:181:11 | 1 | signed char | signed char | essentially Signed type |
+| test.c:182:3:182:8 | 65536 | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:182:3:182:13 | ... >> ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:182:13:182:13 | 1 | signed char | signed char | essentially Signed type |
+| test.c:183:3:183:13 | 4294967296 | unsigned long | unsigned long | essentially Unsigned type |
+| test.c:183:3:183:18 | ... >> ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:183:18:183:18 | 1 | signed char | signed char | essentially Signed type |
+| test.c:184:3:184:6 | 255 | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:184:3:184:11 | ... << ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:184:11:184:11 | 1 | signed char | signed char | essentially Signed type |
+| test.c:185:3:185:8 | 65535 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:185:3:185:13 | ... << ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:185:13:185:13 | 1 | signed char | signed char | essentially Signed type |
+| test.c:189:3:189:6 | 255 | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:189:3:189:13 | ... >> ... | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:189:11:189:13 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:190:3:190:8 | 65535 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:190:3:190:15 | ... >> ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:190:13:190:15 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:191:3:191:13 | 4294967295 | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:191:3:191:20 | ... >> ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:191:18:191:20 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:192:3:192:6 | 255 | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:192:3:192:13 | ... << ... | unsigned char | unsigned char | essentially Unsigned type |
+| test.c:192:11:192:13 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:193:3:193:8 | 65535 | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:193:3:193:15 | ... << ... | unsigned short | unsigned short | essentially Unsigned type |
+| test.c:193:13:193:15 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:194:3:194:13 | 4294967295 | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:194:3:194:20 | ... << ... | unsigned int | unsigned int | essentially Unsigned type |
+| test.c:194:18:194:20 | s32 | int32_t | int32_t | essentially Signed type |
+| test.c:197:3:197:5 | 257 | short | short | essentially Signed type |
+| test.c:197:3:197:5 | 257 | short | signed short | essentially Signed type |
+| test.c:197:3:197:5 | 257 | signed short | short | essentially Signed type |
+| test.c:197:3:197:5 | 257 | signed short | signed short | essentially Signed type |
+| test.c:197:3:197:10 | ... >> ... | int | int | essentially Signed type |
+| test.c:197:10:197:10 | 1 | signed char | signed char | essentially Signed type |
+| test.c:198:3:198:7 | 65537 | int | int | essentially Signed type |
+| test.c:198:3:198:7 | 65537 | int | signed int | essentially Signed type |
+| test.c:198:3:198:7 | 65537 | signed int | int | essentially Signed type |
+| test.c:198:3:198:7 | 65537 | signed int | signed int | essentially Signed type |
+| test.c:198:3:198:12 | ... >> ... | int | int | essentially Signed type |
+| test.c:198:12:198:12 | 1 | signed char | signed char | essentially Signed type |
+| test.c:199:3:199:12 | 4294967297 | long | long | essentially Signed type |
+| test.c:199:3:199:17 | ... >> ... | long | long | essentially Signed type |
+| test.c:199:17:199:17 | 1 | signed char | signed char | essentially Signed type |
diff --git a/c/misra/test/c/misra/test.c b/c/misra/test/c/misra/test.c
index dcdfef4eb4..e271a67e30 100644
--- a/c/misra/test/c/misra/test.c
+++ b/c/misra/test/c/misra/test.c
@@ -159,4 +159,42 @@ void testBitwise() {
   s32 ^ u8;  // Essentially signed, int
   u8 ^ s8;   // Essentially signed, int
   s8 ^ u8;   // Essentially signed, int
+}
+
+void testShifts() {
+  int32_t s32 = 1;
+
+  // Left hand is unsigned and both are constants, so UTLR
+  // In these cases the UTLR is the same as the essential type of
+  // the left operand
+  1U << 1;           // Essentially unsigned char
+  256U << 1;         // Essentially unsigned short
+  65536U << 1;       // Essentially unsigned int
+  2U >> 1;           // Essentially unsigned char
+  32768U >> 1;       // Essentially unsigned short - 2^15 >> 1 = 2^14
+  2147483648U >> 1;  // Essentially unsigned int - 2^31 >> 1 = 2^30
+  4294967295LU << 1; // Essentially unsigned long
+
+  // Left hand is unsigned and both are constants, so UTLR
+  // In these cases the UTLR is not the same as the essential type of
+  // the left operand
+  256U >> 1;        // Essentially unsigned char
+  65536U >> 1;      // Essentially unsigned short
+  4294967296U >> 1; // Essentially unsigned int
+  255U << 1;        // Essentially unsigned short
+  65535U << 1;      // Essentially unsigned int
+
+  // Left hand is unsigned, but left isn't a constant, so essential type of left
+  // operand
+  255U >> s32;        // Essentially unsigned char
+  65535U >> s32;      // Essentially unsigned short
+  4294967295U >> s32; // Essentially unsigned int
+  255U << s32;        // Essentially unsigned char
+  65535U << s32;      // Essentially unsigned short
+  4294967295U << s32; // Essentially unsigned int
+
+  // Left hand operand signed int, so result is standard type
+  257 >> 1;        // Essentially signed int
+  65537 >> 1;      // Essentially signed int
+  4294967297 >> 1; // Essentially signed long
 }
\ No newline at end of file

From aba9528b7341251ee35555a32be7e04f5cfa226d Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 27 Oct 2024 15:41:21 +0000
Subject: [PATCH 03/13] RULE-10-3: Expand test cases for binary bitwise
 operators

---
 ...gnmentOfIncompatibleEssentialType.expected |  6 +++++
 c/misra/test/rules/RULE-10-3/test.c           | 25 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/c/misra/test/rules/RULE-10-3/AssignmentOfIncompatibleEssentialType.expected b/c/misra/test/rules/RULE-10-3/AssignmentOfIncompatibleEssentialType.expected
index 3867abd0ca..b64f970bfe 100644
--- a/c/misra/test/rules/RULE-10-3/AssignmentOfIncompatibleEssentialType.expected
+++ b/c/misra/test/rules/RULE-10-3/AssignmentOfIncompatibleEssentialType.expected
@@ -131,3 +131,9 @@
 | test.c:356:10:356:11 | e1 | Assignment of essentially Enum Type value to an object of essentially Floating type. |
 | test.c:357:10:357:10 | s | Assignment of essentially Signed type value to an object of essentially Floating type. |
 | test.c:358:10:358:10 | u | Assignment of essentially Unsigned type value to an object of essentially Floating type. |
+| test.c:369:12:369:20 | ... & ... | Assignment of essentially Unsigned type value to an object of essentially Signed type. |
+| test.c:370:12:370:20 | ... \| ... | Assignment of essentially Unsigned type value to an object of essentially Signed type. |
+| test.c:371:12:371:20 | ... ^ ... | Assignment of essentially Unsigned type value to an object of essentially Signed type. |
+| test.c:376:20:376:27 | ... & ... | Assignment of value of essentially Signed type of size 2 bytes to an object narrower essential type of size 1 bytes. |
+| test.c:381:23:381:30 | ... & ... | Assignment of value of essentially Unsigned type of size 2 bytes to an object narrower essential type of size 1 bytes. |
+| test.c:384:22:384:29 | ... & ... | Assignment of essentially Signed type value to an object of essentially Unsigned type. |
diff --git a/c/misra/test/rules/RULE-10-3/test.c b/c/misra/test/rules/RULE-10-3/test.c
index 30ab2985ae..f4ad487ae1 100644
--- a/c/misra/test/rules/RULE-10-3/test.c
+++ b/c/misra/test/rules/RULE-10-3/test.c
@@ -357,4 +357,29 @@ void testStructAssignment() {
   s1.f = s;  // NON_COMPLIANT
   s1.f = u;  // NON_COMPLIANT
   s1.f = f;  // COMPLIANT
+}
+
+void testBinaryBitwise() {
+  signed int s32 = 100;          // COMPLIANT - wider
+  signed short s16 = 0;          // COMPLIANT - wider
+  signed char s8 = 0;            // COMPLIANT - wider
+  unsigned int u32 = 100;        // COMPLIANT - by exception 1
+  unsigned char u8 = 0;          // COMPLIANT - by exception 1
+  unsigned short u16 = 0;        // COMPLIANT - by exception 1
+  int x1 = s32 & u32;            // NON_COMPLIANT - integer promotion to u32
+  int x2 = s32 | u32;            // NON_COMPLIANT - integer promotion to u32
+  int x3 = s32 ^ u32;            // NON_COMPLIANT - integer promotion to u32
+  int x4 = s16 & s32;            // COMPLIANT
+  int x5 = s16 & u16;            // COMPLIANT
+  int x6 = s16 & s8;             // COMPLIANT
+  signed short x7 = s16 & s8;    // COMPLIANT
+  signed char x8 = s16 & s8;     // NON_COMPLIANT
+  signed char x9 = s8 & s8;      // COMPLIANT
+  signed short x10 = s8 & s8;    // COMPLIANT
+  unsigned int x11 = u16 & u8;   // COMPLIANT
+  unsigned short x12 = u16 & u8; // COMPLIANT
+  unsigned char x13 = u16 & u8;  // NON_COMPLIANT
+  unsigned char x14 = u8 & u8;   // COMPLIANT
+  unsigned short x15 = u8 & u8;  // COMPLIANT
+  unsigned int x16 = s16 & s8;   // NON_COMPLIANT
 }
\ No newline at end of file

From 5b753e0cbde1f57b22909fc05922e2c61ab032df Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Mon, 28 Oct 2024 08:47:04 -0700
Subject: [PATCH 04/13] Add change note

---
 change_notes/2024-10-28-essential-types-bitwise.md | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 change_notes/2024-10-28-essential-types-bitwise.md

diff --git a/change_notes/2024-10-28-essential-types-bitwise.md b/change_notes/2024-10-28-essential-types-bitwise.md
new file mode 100644
index 0000000000..a382290351
--- /dev/null
+++ b/change_notes/2024-10-28-essential-types-bitwise.md
@@ -0,0 +1,2 @@
+ - `RULE-10-1`, `RULE-10-3`, `RULE-10-4`, `RULE-10-5`, `RULE-10-6`, `RULE-10-7`, `RULE-10-8`, `RULE-12-2` - `OperandsOfAnInappropriateEssentialType.ql`, `AssignmentOfIncompatibleEssentialType.ql`, `OperandsWithMismatchedEssentialTypeCategory.ql`, `InappropriateEssentialTypeCast.ql`, `AssignmentToWiderEssentialType,ql`, `ImplicitConversionOfCompositeExpression.ql`, `InappropriateCastOfCompositeExpression.ql`:
+   - False positives and false negatives removed due to fixing incorrect essential type of the binary bitwise operations `^`, `|` and `&`. Previously the standard type was used, instead of applying the essential type rules which dictate that if both arguments have the same signedness, the essential type will have the same signedness and a rank equal to the larger of the two operands.
\ No newline at end of file

From 37ac088223e3cab5e000fb36103d4fa70056e84a Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:03:53 +0000
Subject: [PATCH 05/13] EssentialType: Merge binary operation implementations

EssentialBinaryArithmeticOperation and
EssentialBinaryBitwiseOperation only differ in their handling of
+ and - operations, so combine the two implementations to reduce
duplication.

In addition, change the characteristic predicate to an allow list.
This ensures we only capture the intended binary operations, and
exclude any others.
---
 .../c/misra/EssentialTypes.qll                | 71 ++++++-------------
 1 file changed, 21 insertions(+), 50 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 4dbe8dbb34..57250d42c5 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -286,11 +286,26 @@ class EssentialConditionalExpr extends EssentialExpr, ConditionalExpr {
   }
 }
 
-class EssentialBinaryArithmeticExpr extends EssentialExpr, BinaryArithmeticOperation {
-  EssentialBinaryArithmeticExpr() {
-    // GNU C extension has min/max which we can ignore
-    not this instanceof MinExpr and
-    not this instanceof MaxExpr
+/**
+ * A binary operation subject to usual conversions, with essential type behaviour as specified by D.7.9.
+ */
+class EssentialBinaryOperationSubjectToUsualConversions extends EssentialExpr, BinaryOperation {
+  EssentialBinaryOperationSubjectToUsualConversions() {
+    this instanceof MulExpr
+    or
+    this instanceof DivExpr
+    or
+    this instanceof RemExpr
+    or
+    this instanceof AddExpr
+    or
+    this instanceof SubExpr
+    or
+    this instanceof BitwiseAndExpr
+    or
+    this instanceof BitwiseOrExpr
+    or
+    this instanceof BitwiseXorExpr
   }
 
   override Type getEssentialType() {
@@ -353,51 +368,7 @@ class EssentialBinaryArithmeticExpr extends EssentialExpr, BinaryArithmeticOpera
   }
 }
 
-class EssentialBinaryBitwiseExpr extends EssentialExpr, BinaryBitwiseOperation {
-  EssentialBinaryBitwiseExpr() {
-    not this instanceof LShiftExpr and
-    not this instanceof RShiftExpr
-  }
-
-  override Type getEssentialType() {
-    exists(
-      Type leftEssentialType, Type rightEssentialType,
-      EssentialTypeCategory leftEssentialTypeCategory,
-      EssentialTypeCategory rightEssentialTypeCategory
-    |
-      leftEssentialType = getEssentialType(getLeftOperand()) and
-      rightEssentialType = getEssentialType(getRightOperand()) and
-      leftEssentialTypeCategory = getEssentialTypeCategory(leftEssentialType) and
-      rightEssentialTypeCategory = getEssentialTypeCategory(rightEssentialType)
-    |
-      if
-        leftEssentialTypeCategory = EssentiallySignedType() and
-        rightEssentialTypeCategory = EssentiallySignedType()
-      then
-        if exists(getValue())
-        then result = stlr(this)
-        else (
-          if leftEssentialType.getSize() > rightEssentialType.getSize()
-          then result = leftEssentialType
-          else result = rightEssentialType
-        )
-      else
-        if
-          leftEssentialTypeCategory = EssentiallyUnsignedType() and
-          rightEssentialTypeCategory = EssentiallyUnsignedType()
-        then
-          if exists(getValue())
-          then result = utlr(this)
-          else (
-            if leftEssentialType.getSize() > rightEssentialType.getSize()
-            then result = leftEssentialType
-            else result = rightEssentialType
-          )
-        else result = this.getStandardType()
-    )
-  }
-}
-
+// }
 /**
  * A named Enum type, as per D.5.
  */

From 9dc3f1894b3b853c7c8459cc25715698d06eaff2 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:19:27 +0000
Subject: [PATCH 06/13] EssentialType: extract Add/Sub expressions

Extract out add/sub expressions special behaviour to improve
clarity. This commit also simplifies the add case by avoiding
referring to left/right explicitly.
---
 .../c/misra/EssentialTypes.qll                | 66 ++++++++++++-------
 1 file changed, 44 insertions(+), 22 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 57250d42c5..2852f5d842 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -342,28 +342,50 @@ class EssentialBinaryOperationSubjectToUsualConversions extends EssentialExpr, B
             then result = leftEssentialType
             else result = rightEssentialType
           )
-        else
-          if
-            this instanceof AddExpr and
-            (
-              leftEssentialTypeCategory = EssentiallyCharacterType()
-              or
-              rightEssentialTypeCategory = EssentiallyCharacterType()
-            ) and
-            (
-              leftEssentialTypeCategory =
-                [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
-              or
-              rightEssentialTypeCategory =
-                [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
-            )
-            or
-            this instanceof SubExpr and
-            leftEssentialTypeCategory = EssentiallyCharacterType() and
-            rightEssentialTypeCategory =
-              [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
-          then result instanceof PlainCharType
-          else result = this.getStandardType()
+        else result = this.getStandardType()
+    )
+  }
+}
+
+/**
+ * An add expression, with essential type behaviour as specified by D.7.9.
+ */
+class EssentialAddExpr extends EssentialBinaryOperationSubjectToUsualConversions, AddExpr {
+  override Type getEssentialType() {
+    exists(
+      EssentialTypeCategory operandTypeCategory, EssentialTypeCategory otherOperandTypeCategory
+    |
+      operandTypeCategory = getEssentialTypeCategory(getEssentialType(getAnOperand())) and
+      otherOperandTypeCategory = getEssentialTypeCategory(getEssentialType(getAnOperand()))
+    |
+      if
+        operandTypeCategory = EssentiallyCharacterType() and
+        otherOperandTypeCategory =
+          [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
+      then result instanceof PlainCharType
+      else result = super.getEssentialType()
+    )
+  }
+}
+
+/**
+ * A sub expression, with essential type behaviour as specified by D.7.9.
+ */
+class EssentialSubExpr extends EssentialBinaryOperationSubjectToUsualConversions, SubExpr {
+  override Type getEssentialType() {
+    exists(
+      EssentialTypeCategory leftEssentialTypeCategory,
+      EssentialTypeCategory rightEssentialTypeCategory
+    |
+      leftEssentialTypeCategory = getEssentialTypeCategory(getEssentialType(getLeftOperand())) and
+      rightEssentialTypeCategory = getEssentialTypeCategory(getEssentialType(getRightOperand()))
+    |
+      if
+        leftEssentialTypeCategory = EssentiallyCharacterType() and
+        rightEssentialTypeCategory =
+          [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
+      then result instanceof PlainCharType
+      else result = super.getEssentialType()
     )
   }
 }

From 29420e93e0f286a6cafe06a6ef44989c2e517676 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:33:13 +0000
Subject: [PATCH 07/13] EssentialType: Combine binary cases

Reduce repitition through combining cases.
---
 .../c/misra/EssentialTypes.qll                | 26 +++++++------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 2852f5d842..633660b952 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -320,29 +320,21 @@ class EssentialBinaryOperationSubjectToUsualConversions extends EssentialExpr, B
       rightEssentialTypeCategory = getEssentialTypeCategory(rightEssentialType)
     |
       if
-        leftEssentialTypeCategory = EssentiallySignedType() and
-        rightEssentialTypeCategory = EssentiallySignedType()
+        leftEssentialTypeCategory = rightEssentialTypeCategory and
+        leftEssentialTypeCategory =
+          [EssentiallyUnsignedType(), EssentiallySignedType().(TEssentialTypeCategory)]
       then
         if exists(getValue())
-        then result = stlr(this)
-        else (
+        then (
+          leftEssentialTypeCategory = EssentiallySignedType() and result = stlr(this)
+          or
+          leftEssentialTypeCategory = EssentiallyUnsignedType() and result = utlr(this)
+        ) else (
           if leftEssentialType.getSize() > rightEssentialType.getSize()
           then result = leftEssentialType
           else result = rightEssentialType
         )
-      else
-        if
-          leftEssentialTypeCategory = EssentiallyUnsignedType() and
-          rightEssentialTypeCategory = EssentiallyUnsignedType()
-        then
-          if exists(getValue())
-          then result = utlr(this)
-          else (
-            if leftEssentialType.getSize() > rightEssentialType.getSize()
-            then result = leftEssentialType
-            else result = rightEssentialType
-          )
-        else result = this.getStandardType()
+      else result = this.getStandardType()
     )
   }
 }

From 62da9c88ba9c6a5acb88f79a94405947f3505a4c Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:45:14 +0000
Subject: [PATCH 08/13] EssentialType: Simplify (Signed or Unsigned)

---
 .../c/misra/EssentialTypes.qll                | 25 ++++++++-----------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 633660b952..555d3d2b2d 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -31,17 +31,19 @@ class EssentialTypeCategory extends TEssentialTypeCategory {
   }
 }
 
+class EssentiallySignedOrUnsignedType extends EssentialTypeCategory {
+  EssentiallySignedOrUnsignedType() {
+    this = EssentiallySignedType() or this = EssentiallyUnsignedType()
+  }
+}
+
 /**
  * An expression in the program that evaluates to a compile time constant signed or unsigned integer.
  */
 private class ConstantIntegerExpr extends Expr {
   pragma[noinline]
   ConstantIntegerExpr() {
-    getEssentialTypeCategory(this.getType()) =
-      [
-        EssentiallyUnsignedType().(EssentialTypeCategory),
-        EssentiallySignedType().(EssentialTypeCategory)
-      ] and
+    getEssentialTypeCategory(this.getType()) instanceof EssentiallySignedOrUnsignedType and
     exists(this.getValue().toFloat()) and
     not this instanceof Conversion
   }
@@ -235,9 +237,7 @@ class EssentialUnaryPlusExpr extends EssentialExpr, UnaryPlusExpr {
       operandEssentialType = getEssentialType(getOperand()) and
       operandEssentialTypeCategory = getEssentialTypeCategory(operandEssentialType)
     |
-      if
-        operandEssentialTypeCategory =
-          [EssentiallyUnsignedType().(TEssentialTypeCategory), EssentiallySignedType()]
+      if operandEssentialTypeCategory instanceof EssentiallySignedOrUnsignedType
       then result = operandEssentialType
       else result = getStandardType()
     )
@@ -321,8 +321,7 @@ class EssentialBinaryOperationSubjectToUsualConversions extends EssentialExpr, B
     |
       if
         leftEssentialTypeCategory = rightEssentialTypeCategory and
-        leftEssentialTypeCategory =
-          [EssentiallyUnsignedType(), EssentiallySignedType().(TEssentialTypeCategory)]
+        leftEssentialTypeCategory instanceof EssentiallySignedOrUnsignedType
       then
         if exists(getValue())
         then (
@@ -352,8 +351,7 @@ class EssentialAddExpr extends EssentialBinaryOperationSubjectToUsualConversions
     |
       if
         operandTypeCategory = EssentiallyCharacterType() and
-        otherOperandTypeCategory =
-          [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
+        otherOperandTypeCategory instanceof EssentiallySignedOrUnsignedType
       then result instanceof PlainCharType
       else result = super.getEssentialType()
     )
@@ -374,8 +372,7 @@ class EssentialSubExpr extends EssentialBinaryOperationSubjectToUsualConversions
     |
       if
         leftEssentialTypeCategory = EssentiallyCharacterType() and
-        rightEssentialTypeCategory =
-          [EssentiallySignedType(), EssentiallyUnsignedType().(TEssentialTypeCategory)]
+        rightEssentialTypeCategory instanceof EssentiallySignedOrUnsignedType
       then result instanceof PlainCharType
       else result = super.getEssentialType()
     )

From cd8ea6767da83d0783502e826a4c7be6b86bdb05 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:48:01 +0000
Subject: [PATCH 09/13] EssentialType: Reduce duplication in conditional calc

Avoid repeating code for both the signed and unsigned cases.
---
 .../src/codingstandards/c/misra/EssentialTypes.qll | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 555d3d2b2d..97a9604f58 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -267,21 +267,13 @@ class EssentialConditionalExpr extends EssentialExpr, ConditionalExpr {
       then result = thenEssentialType
       else
         if
-          getEssentialTypeCategory(thenEssentialType) = EssentiallySignedType() and
-          getEssentialTypeCategory(elseEssentialType) = EssentiallySignedType()
+          getEssentialTypeCategory(thenEssentialType) = getEssentialTypeCategory(elseEssentialType) and
+          getEssentialTypeCategory(thenEssentialType) instanceof EssentiallySignedOrUnsignedType
         then
           if thenEssentialType.getSize() > elseEssentialType.getSize()
           then result = thenEssentialType
           else result = elseEssentialType
-        else
-          if
-            getEssentialTypeCategory(thenEssentialType) = EssentiallyUnsignedType() and
-            getEssentialTypeCategory(elseEssentialType) = EssentiallyUnsignedType()
-          then
-            if thenEssentialType.getSize() > elseEssentialType.getSize()
-            then result = thenEssentialType
-            else result = elseEssentialType
-          else result = this.getStandardType()
+        else result = this.getStandardType()
     )
   }
 }

From 7a465dd340948eb3a6a5a0e6f5b14c068bc601a7 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 23:52:35 +0000
Subject: [PATCH 10/13] EssentialType: Add maxRank predicate

---
 .../c/misra/EssentialTypes.qll                | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 97a9604f58..0a4e64e98d 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -257,6 +257,13 @@ class EssentialUnaryMinusExpr extends EssentialExpr, UnaryMinusExpr {
   }
 }
 
+bindingset[essentialTypeA, essentialTypeB]
+private Type maxRankType(Type essentialTypeA, Type essentialTypeB) {
+  if essentialTypeA.getSize() > essentialTypeB.getSize()
+  then result = essentialTypeA
+  else result = essentialTypeB
+}
+
 class EssentialConditionalExpr extends EssentialExpr, ConditionalExpr {
   override Type getEssentialType() {
     exists(Type thenEssentialType, Type elseEssentialType |
@@ -269,10 +276,7 @@ class EssentialConditionalExpr extends EssentialExpr, ConditionalExpr {
         if
           getEssentialTypeCategory(thenEssentialType) = getEssentialTypeCategory(elseEssentialType) and
           getEssentialTypeCategory(thenEssentialType) instanceof EssentiallySignedOrUnsignedType
-        then
-          if thenEssentialType.getSize() > elseEssentialType.getSize()
-          then result = thenEssentialType
-          else result = elseEssentialType
+        then result = maxRankType(thenEssentialType, elseEssentialType)
         else result = this.getStandardType()
     )
   }
@@ -316,15 +320,11 @@ class EssentialBinaryOperationSubjectToUsualConversions extends EssentialExpr, B
         leftEssentialTypeCategory instanceof EssentiallySignedOrUnsignedType
       then
         if exists(getValue())
-        then (
+        then
           leftEssentialTypeCategory = EssentiallySignedType() and result = stlr(this)
           or
           leftEssentialTypeCategory = EssentiallyUnsignedType() and result = utlr(this)
-        ) else (
-          if leftEssentialType.getSize() > rightEssentialType.getSize()
-          then result = leftEssentialType
-          else result = rightEssentialType
-        )
+        else result = maxRankType(leftEssentialType, rightEssentialType)
       else result = this.getStandardType()
     )
   }

From 3fd82fd7bf2cb2a61f2c1c476d53806f2e932834 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Mon, 13 Jan 2025 00:06:10 +0000
Subject: [PATCH 11/13] EssentialType: Fix test comments

---
 c/misra/test/c/misra/test.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/c/misra/test/c/misra/test.c b/c/misra/test/c/misra/test.c
index e271a67e30..7bcb5d7bad 100644
--- a/c/misra/test/c/misra/test.c
+++ b/c/misra/test/c/misra/test.c
@@ -139,8 +139,8 @@ void testBitwise() {
   s32 ^ s16; // Essentially signed, int
   s16 ^ s32; // Essentially signed, int
 
-  u32 & s32; // Essentially signed, int
-  s32 & u32; // Essentially signed, int
+  u32 & s32; // Essentially unsigned, int
+  s32 & u32; // Essentially unsigned, int
   u8 & s32;  // Essentially signed, int
   s32 & u8;  // Essentially signed, int
   u8 & s8;   // Essentially signed, int

From 8a070839bb679f5eb7ed57638cfb3ed4ab662485 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Mon, 13 Jan 2025 00:11:41 +0000
Subject: [PATCH 12/13] Avoid formatting colisions

---
 c/misra/test/c/misra/test.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/c/misra/test/c/misra/test.c b/c/misra/test/c/misra/test.c
index 7bcb5d7bad..36a3eb0b10 100644
--- a/c/misra/test/c/misra/test.c
+++ b/c/misra/test/c/misra/test.c
@@ -82,8 +82,8 @@ void testControlChar() {
 }
 
 #include <stdint.h>
-
-void testBitwise() {
+// clang-format off
+void testBitwise() { // Clang format disabled to avoid confusion with variable declarations
   uint8_t u8 = 0;
   uint16_t u16 = 0;
   uint32_t u32 = 0;
@@ -160,7 +160,7 @@ void testBitwise() {
   u8 ^ s8;   // Essentially signed, int
   s8 ^ u8;   // Essentially signed, int
 }
-
+// clang-format on
 void testShifts() {
   int32_t s32 = 1;
 

From eae738532551f269a1c5cf07f6748c6ed708d6ee Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Thu, 16 Jan 2025 23:02:20 +0000
Subject: [PATCH 13/13] Remove stray comment

---
 c/misra/src/codingstandards/c/misra/EssentialTypes.qll | 1 -
 1 file changed, 1 deletion(-)

diff --git a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
index 0a4e64e98d..50b588d422 100644
--- a/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
+++ b/c/misra/src/codingstandards/c/misra/EssentialTypes.qll
@@ -371,7 +371,6 @@ class EssentialSubExpr extends EssentialBinaryOperationSubjectToUsualConversions
   }
 }
 
-// }
 /**
  * A named Enum type, as per D.5.
  */