From 6fa8e60570b70f5f6a577d0d5fcae3e161be4c65 Mon Sep 17 00:00:00 2001
From: primoly <168267431+primoly@users.noreply.github.com>
Date: Wed, 16 Jul 2025 20:25:44 +0200
Subject: [PATCH] Fix `uadd_overflow_trap` in interpreter

---
 cranelift/codegen/src/ir/instructions.rs | 8 ++++++--
 cranelift/interpreter/src/step.rs        | 8 +++-----
 cranelift/src/interpret.rs               | 1 +
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/cranelift/codegen/src/ir/instructions.rs b/cranelift/codegen/src/ir/instructions.rs
index 2b8eeff60094..b36912d9583a 100644
--- a/cranelift/codegen/src/ir/instructions.rs
+++ b/cranelift/codegen/src/ir/instructions.rs
@@ -491,7 +491,9 @@ impl InstructionData {
     /// `None`.
     pub fn trap_code(&self) -> Option<TrapCode> {
         match *self {
-            Self::CondTrap { code, .. } | Self::Trap { code, .. } => Some(code),
+            Self::CondTrap { code, .. }
+            | Self::IntAddTrap { code, .. }
+            | Self::Trap { code, .. } => Some(code),
             _ => None,
         }
     }
@@ -519,7 +521,9 @@ impl InstructionData {
     /// trap code. Otherwise, return `None`.
     pub fn trap_code_mut(&mut self) -> Option<&mut TrapCode> {
         match self {
-            Self::CondTrap { code, .. } | Self::Trap { code, .. } => Some(code),
+            Self::CondTrap { code, .. }
+            | Self::IntAddTrap { code, .. }
+            | Self::Trap { code, .. } => Some(code),
             _ => None,
         }
     }
diff --git a/cranelift/interpreter/src/step.rs b/cranelift/interpreter/src/step.rs
index 25b402c978ca..3bf387bd4348 100644
--- a/cranelift/interpreter/src/step.rs
+++ b/cranelift/interpreter/src/step.rs
@@ -771,12 +771,10 @@ where
             assign_multiple(&[sum, DataValueExt::bool(carry, false, types::I8)?])
         }
         Opcode::UaddOverflowTrap => {
-            let sum = DataValueExt::add(arg(0), arg(1))?;
-            let carry = sum < arg(0) && sum < arg(1);
-            if carry {
-                ControlFlow::Trap(CraneliftTrap::User(trap_code()))
-            } else {
+            if let Some(sum) = DataValueExt::uadd_checked(arg(0), arg(1))? {
                 assign(sum)
+            } else {
+                ControlFlow::Trap(CraneliftTrap::User(trap_code()))
             }
         }
         Opcode::SsubOverflowBin => {
diff --git a/cranelift/src/interpret.rs b/cranelift/src/interpret.rs
index 4d68ce3d2d53..d6fa8664c90a 100644
--- a/cranelift/src/interpret.rs
+++ b/cranelift/src/interpret.rs
@@ -126,6 +126,7 @@ impl FileInterpreter {
                     let state = InterpreterState::default().with_function_store(env.clone());
                     match Interpreter::new(state).call_by_name(func_name, args) {
                         Ok(ControlFlow::Return(results)) => Ok(results.to_vec()),
+                        Ok(ControlFlow::Trap(trap)) => Err(trap.to_string()),
                         Ok(_) => panic!("Unexpected returned control flow--this is likely a bug."),
                         Err(t) => Err(t.to_string()),
                     }