feat: add on_assert_failed method to the Host trait

CHANGELOG.md

@@ -19,6 +19,7 @@
 - Updated Winterfell dependency to v0.7 (#1121).
 - Added methods `StackOutputs::get_stack_item()` and `StackOutputs::get_stack_word()` (#1155).
 - Added [Tracing](https://crates.io/crates/tracing) logger to the VM (#1139).
+- Added `on_assert_failed()` method to the Host trait (#1197).
 
 #### CLI
 - Introduced the `!use` command for the Miden REPL (#1162).

air/src/constraints/stack/op_flags/mod.rs

@@ -624,7 +624,7 @@ impl<E: FieldElement> OpFlags<E> {
     /// Operation Flag of ASSERT operation.
     #[inline(always)]
     pub fn assert(&self) -> E {
-        self.degree7_op_flags[get_op_index(Operation::Assert(ZERO).op_code())]
+        self.degree7_op_flags[get_op_index(Operation::Assert(0).op_code())]
     }
 
     /// Operation Flag of EQ operation.

air/src/constraints/stack/system_ops/tests.rs

@@ -102,7 +102,7 @@ pub fn get_fmpupdate_test_frame(a: u64) -> EvaluationFrame<Felt> {
 /// returns an EvaluationFrame for testing.
 pub fn get_assert_test_frame() -> EvaluationFrame<Felt> {
     // frame initialized with a fmpupdate operation using it's unique opcode.
-    let mut frame = generate_evaluation_frame(Operation::Assert(ZERO).op_code() as usize);
+    let mut frame = generate_evaluation_frame(Operation::Assert(0).op_code() as usize);
 
     // Set the output. The top element in the current frame of the stack should be ONE.
     frame.current_mut()[STACK_TRACE_OFFSET] = ONE;

assembly/src/assembler/instruction/ext2_ops.rs

@@ -1,4 +1,4 @@
-use super::{AssemblyError, CodeBlock, Operation::*, SpanBuilder, ZERO};
+use super::{AssemblyError, CodeBlock, Operation::*, SpanBuilder};
 use vm_core::AdviceInjector::Ext2Inv;
 
 /// Given a stack in the following initial configuration [b1, b0, a1, a0, ...] where a = (a0, a1)
@@ -60,9 +60,9 @@ pub fn ext2_div(span: &mut SpanBuilder) -> Result<Option<CodeBlock>, AssemblyErr
         Ext2Mul,        // [b1', b0', 0, 1, a1, a0, ...]
         MovUp2,         // [0, b1', b0', 1, a1, a0, ...]
         Eqz,            // [1, b1', b0', 1, a1, a0, ...]
-        Assert(ZERO),   // [b1', b0', 1, a1, a0, ...]
+        Assert(0),      // [b1', b0', 1, a1, a0, ...]
         MovUp2,         // [1, b1', b0', a1, a0, ...]
-        Assert(ZERO),   // [b1', b0', a1, a0, ...]
+        Assert(0),      // [b1', b0', a1, a0, ...]
         Ext2Mul,        // [b1', b0', a1*b1', a0*b0', ...]
         Drop,           // [b0', a1*b1', a0*b0'...]
         Drop            // [a1*b1', a0*b0'...]
@@ -120,9 +120,9 @@ pub fn ext2_inv(span: &mut SpanBuilder) -> Result<Option<CodeBlock>, AssemblyErr
         Ext2Mul,        // [a1', a0', 0, 1, ...]
         MovUp2,         // [0, a1', a0', 1, ...]
         Eqz,            // [1, a1', a0', 1, ...]
-        Assert(ZERO),   // [a1', a0', 1, ...]
+        Assert(0),      // [a1', a0', 1, ...]
         MovUp2,         // [1, a1', a0', ...]
-        Assert(ZERO),   // [a1', a0', ...]
+        Assert(0),      // [a1', a0', ...]
     ];
     span.add_ops(ops)
 }

assembly/src/assembler/instruction/field_ops.rs

@@ -13,7 +13,7 @@ const TWO: Felt = Felt::new(2);
 /// Asserts that the top two words in the stack are equal.
 ///
 /// VM cycles: 11 cycles
-pub fn assertw(span: &mut SpanBuilder, err_code: Felt) -> Result<Option<CodeBlock>, AssemblyError> {
+pub fn assertw(span: &mut SpanBuilder, err_code: u32) -> Result<Option<CodeBlock>, AssemblyError> {
     span.add_ops([
         MovUp4,
         Eq,
@@ -122,7 +122,7 @@ pub fn append_pow2_op(span: &mut SpanBuilder) {
     // drop the top two elements bit and exp value of the latest bit.
     span.push_ops([Drop, Drop]);
     // taking `b` to the top and asserting if it's equal to ZERO after all the right shifts.
-    span.push_ops([Swap, Eqz, Assert(ZERO)]);
+    span.push_ops([Swap, Eqz, Assert(0)]);
 }
 
 // EXPONENTIATION OPERATION
@@ -151,7 +151,7 @@ pub fn exp(span: &mut SpanBuilder, num_pow_bits: u8) -> Result<Option<CodeBlock>
     span.push_ops([Drop, Drop]);
 
     // taking `b` to the top and asserting if it's equal to ZERO after all the right shifts.
-    span.push_ops([Swap, Eqz, Assert(ZERO)]);
+    span.push_ops([Swap, Eqz, Assert(0)]);
     Ok(None)
 }
 

assembly/src/assembler/instruction/mod.rs

@@ -37,20 +37,14 @@ impl Assembler {
         }
 
         let result = match instruction {
-            Instruction::Assert => span.add_op(Assert(ZERO)),
-            Instruction::AssertWithError(err_code) => span.add_op(Assert(Felt::from(*err_code))),
-            Instruction::AssertEq => span.add_ops([Eq, Assert(ZERO)]),
-            Instruction::AssertEqWithError(err_code) => {
-                span.add_ops([Eq, Assert(Felt::from(*err_code))])
-            }
-            Instruction::AssertEqw => field_ops::assertw(span, ZERO),
-            Instruction::AssertEqwWithError(err_code) => {
-                field_ops::assertw(span, Felt::from(*err_code))
-            }
-            Instruction::Assertz => span.add_ops([Eqz, Assert(ZERO)]),
-            Instruction::AssertzWithError(err_code) => {
-                span.add_ops([Eqz, Assert(Felt::from(*err_code))])
-            }
+            Instruction::Assert => span.add_op(Assert(0)),
+            Instruction::AssertWithError(err_code) => span.add_op(Assert(*err_code)),
+            Instruction::AssertEq => span.add_ops([Eq, Assert(0)]),
+            Instruction::AssertEqWithError(err_code) => span.add_ops([Eq, Assert(*err_code)]),
+            Instruction::AssertEqw => field_ops::assertw(span, 0),
+            Instruction::AssertEqwWithError(err_code) => field_ops::assertw(span, *err_code),
+            Instruction::Assertz => span.add_ops([Eqz, Assert(0)]),
+            Instruction::AssertzWithError(err_code) => span.add_ops([Eqz, Assert(*err_code)]),
 
             Instruction::Add => span.add_op(Add),
             Instruction::AddImm(imm) => field_ops::add_imm(span, *imm),

core/src/operations/mod.rs

@@ -22,7 +22,7 @@ pub enum Operation {
     ///
     /// The internal value specifies an error code associated with the error in case when the
     /// execution fails.
-    Assert(Felt),
+    Assert(u32),
 
     /// Pops an element off the stack, adds the current value of the `fmp` register to it, and
     /// pushes the result back onto the stack.

miden/tests/integration/operations/sys_ops.rs

@@ -19,7 +19,7 @@ fn assert_with_code() {
     test.expect_stack(&[]);
 
     // triggered assertion captures both the VM cycle and error code
-    let expected_err = "FailedAssertion(1, 123)";
+    let expected_err = "FailedAssertion { clk: 1, err_code: 123, err_msg: None }";
     let test = build_op_test!(asm_op, &[0]);
     test.expect_error(TestError::ExecutionError(&expected_err));
 }

processor/src/errors.rs

@@ -28,15 +28,27 @@ pub enum ExecutionError {
     DivideByZero(u32),
     EventError(String),
     Ext2InttError(Ext2InttError),
-    FailedAssertion(u32, Felt),
+    FailedAssertion {
+        clk: u32,
+        err_code: u32,
+        err_msg: Option<String>,
+    },
     InvalidFmpValue(Felt, Felt),
     InvalidFriDomainSegment(u64),
     InvalidFriLayerFolding(QuadFelt, QuadFelt),
-    InvalidMemoryRange { start_addr: u64, end_addr: u64 },
+    InvalidMemoryRange {
+        start_addr: u64,
+        end_addr: u64,
+    },
     InvalidStackDepthOnReturn(usize),
     InvalidStackWordOffset(usize),
-    InvalidTreeDepth { depth: Felt },
-    InvalidTreeNodeIndex { depth: Felt, value: Felt },
+    InvalidTreeDepth {
+        depth: Felt,
+    },
+    InvalidTreeNodeIndex {
+        depth: Felt,
+        value: Felt,
+    },
     MemoryAddressOutOfBounds(u64),
     MerkleStoreMergeFailed(MerkleError),
     MerkleStoreLookupFailed(MerkleError),
@@ -90,8 +102,19 @@ impl Display for ExecutionError {
             DivideByZero(clk) => write!(f, "Division by zero at clock cycle {clk}"),
             EventError(error) => write!(f, "Failed to process event - {error}"),
             Ext2InttError(err) => write!(f, "Failed to execute Ext2Intt operation: {err}"),
-            FailedAssertion(clk, err_code) => {
-                write!(f, "Assertion failed at clock cycle {clk} with error code {err_code}")
+            FailedAssertion {
+                clk,
+                err_code,
+                err_msg,
+            } => {
+                if let Some(err_msg) = err_msg {
+                    write!(
+                        f,
+                        "Assertion failed at clock cycle {clk} with error code {err_code}: {err_msg}"
+                    )
+                } else {
+                    write!(f, "Assertion failed at clock cycle {clk} with error code {err_code}")
+                }
             }
             InvalidFmpValue(old, new) => {
                 write!(f, "Updating FMP register from {old} to {new} failed because {new} is outside of {FMP_MIN}..{FMP_MAX}")

processor/src/host/mod.rs

@@ -82,6 +82,15 @@ pub trait Host {
         Ok(HostResponse::None)
     }
 
+    /// Handles the failure of the assertion instruction.
+    fn on_assert_failed<S: ProcessState>(&mut self, process: &S, err_code: u32) -> ExecutionError {
+        ExecutionError::FailedAssertion {
+            clk: process.clk(),
+            err_code,
+            err_msg: None,
+        }
+    }
+
     /// Pops an element from the advice stack and returns it.
     ///
     /// # Errors
@@ -172,6 +181,10 @@ where
     ) -> Result<HostResponse, ExecutionError> {
         H::on_event(self, process, event_id)
     }
+
+    fn on_assert_failed<S: ProcessState>(&mut self, process: &S, err_code: u32) -> ExecutionError {
+        H::on_assert_failed(self, process, err_code)
+    }
 }
 
 // HOST RESPONSE

processor/src/operations/sys_ops.rs

@@ -17,9 +17,9 @@ where
     ///
     /// # Errors
     /// Returns an error if the popped value is not ONE.
-    pub(super) fn op_assert(&mut self, err_code: Felt) -> Result<(), ExecutionError> {
+    pub(super) fn op_assert(&mut self, err_code: u32) -> Result<(), ExecutionError> {
         if self.stack.get(0) != ONE {
-            return Err(ExecutionError::FailedAssertion(self.system.clk(), err_code));
+            return Err(self.host.borrow_mut().on_assert_failed(self, err_code));
         }
         self.stack.shift_left(1);
         Ok(())
@@ -128,7 +128,7 @@ mod tests {
         process.execute_op(Operation::Swap).unwrap();
         process.execute_op(Operation::Drop).unwrap();
 
-        assert!(process.execute_op(Operation::Assert(ZERO)).is_ok());
+        assert!(process.execute_op(Operation::Assert(0)).is_ok());
     }
 
     #[test]