From 458ee13345a93021f1da581d4cc9ccc36b2918ce Mon Sep 17 00:00:00 2001
From: Mathias Vorreiter Pedersen <mathiasvp@github.com>
Date: Tue, 19 Mar 2024 16:23:57 +0000
Subject: [PATCH] C++: Add constant analysis for bitwise operations now that
 these are no longer constant folded by IR construction.

---
 .../implementation/raw/constant/ConstantAnalysis.qll |  6 ++++++
 .../semmle/code/cpp/ir/internal/IntegerPartial.qll   | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/constant/ConstantAnalysis.qll b/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/constant/ConstantAnalysis.qll
index 47b744b3f7c..f65799f9a61 100644
--- a/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/constant/ConstantAnalysis.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/constant/ConstantAnalysis.qll
@@ -38,6 +38,12 @@ private int getBinaryInstructionValue(BinaryInstruction instr) {
     or
     instr instanceof DivInstruction and result = div(left, right)
     or
+    instr instanceof BitOrInstruction and result = bitOr(left, right)
+    or
+    instr instanceof BitAndInstruction and result = bitAnd(left, right)
+    or
+    instr instanceof BitXorInstruction and result = bitXor(left, right)
+    or
     instr instanceof CompareEQInstruction and result = compareEQ(left, right)
     or
     instr instanceof CompareNEInstruction and result = compareNE(left, right)
diff --git a/cpp/ql/lib/semmle/code/cpp/ir/internal/IntegerPartial.qll b/cpp/ql/lib/semmle/code/cpp/ir/internal/IntegerPartial.qll
index 0e24f283b17..33681dde0d4 100644
--- a/cpp/ql/lib/semmle/code/cpp/ir/internal/IntegerPartial.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/internal/IntegerPartial.qll
@@ -89,6 +89,18 @@ int compareLE(int a, int b) { if a <= b then result = 1 else result = 0 }
 bindingset[a, b]
 int compareGE(int a, int b) { if a >= b then result = 1 else result = 0 }
 
+/** Returns `a >= b`. */
+bindingset[a, b]
+int bitOr(int a, int b) { result = a.bitOr(b) }
+
+/** Returns `a >= b`. */
+bindingset[a, b]
+int bitAnd(int a, int b) { result = a.bitAnd(b) }
+
+/** Returns `a >= b`. */
+bindingset[a, b]
+int bitXor(int a, int b) { result = a.bitXor(b) }
+
 /**
  * Returns `-a`. If the negation would overflow, there is no result.
  */