fix: explicit constraint violations.

Author: l-monninger

aptos-move/aptos-vm/src/aptos_vm.rs

@@ -750,10 +750,11 @@ impl AptosVM {
             let module_id = traversal_context
                 .referenced_module_ids
                 .alloc(entry_fn.module().clone());
-            session.check_dependencies_and_charge_gas(gas_meter, traversal_context, [(
-                module_id.address(),
-                module_id.name(),
-            )])?;
+            session.check_dependencies_and_charge_gas(
+                gas_meter,
+                traversal_context,
+                [(module_id.address(), module_id.name())],
+            )?;
         }
 
         let function =
@@ -1318,7 +1319,14 @@ impl AptosVM {
                     )?;
                 } else {
                     return Err(PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED)
-                        .finish(Location::Undefined));
+                        .with_message(format!(
+                            "initializer not found in module '{}'",
+                            module.self_id().name()
+                        ))
+                        .finish(Location::Constraint(format!(
+                            "module must have an initializer function name '{}'",
+                            init_func_name
+                        ))));
                 }
             }
         }
@@ -1541,7 +1549,9 @@ impl AptosVM {
     fn metadata_validation_error(msg: &str) -> VMError {
         PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED)
             .with_message(format!("metadata and code bundle mismatch: {}", msg))
-            .finish(Location::Undefined)
+            .finish(Location::Constraint(
+                "metadata must match the code bundle".to_string(),
+            ))
     }
 
     fn validate_signed_transaction(

aptos-move/aptos-vm/src/verifier/resource_groups.rs

@@ -22,7 +22,9 @@ fn metadata_validation_err(msg: &str) -> Result<(), VMError> {
 fn metadata_validation_error(msg: &str) -> VMError {
     PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED)
         .with_message(format!("metadata and code bundle mismatch: {}", msg))
-        .finish(Location::Undefined)
+        .finish(Location::Constraint(
+            "metadata must match code bundle".to_string(),
+        ))
 }
 
 /// Perform validation and upgrade checks on resource groups

third_party/move/move-binary-format/src/errors.rs

@@ -21,6 +21,7 @@ pub enum Location {
     Undefined,
     Script,
     Module(ModuleId),
+    Constraint(String),
 }
 
 /// A representation of the execution state (e.g., stack trace) at an
@@ -103,6 +104,21 @@ impl VMError {
                             message,
                         };
                     },
+                    Location::Constraint(constraint) => {
+                        let message_string = message.unwrap_or_else(|| "opaque error".to_string());
+
+                        return VMStatus::Error {
+                            status_code: major_status,
+                            sub_status,
+                            message: Some(
+                                format!(
+                                    "constraint violation: {} with: {}",
+                                    constraint, message_string
+                                )
+                                .to_string(),
+                            ),
+                        };
+                    },
                 };
                 // Errors for OUT_OF_GAS do not always have index set: if it does not, it should already return above.
                 debug_assert!(
@@ -246,6 +262,7 @@ impl VMError {
             Location::Module(id) => {
                 format!("0x{}::{}", id.address().short_str_lossless(), id.name())
             },
+            Location::Constraint(constraint) => format!("constraint: {}", constraint),
         };
         let indices = if comparison_mode {
             // During comparison testing, abstract this data.
@@ -532,6 +549,7 @@ impl fmt::Display for Location {
             Location::Undefined => write!(f, "UNDEFINED"),
             Location::Script => write!(f, "Script"),
             Location::Module(id) => write!(f, "Module {:?}", id),
+            Location::Constraint(constraint) => write!(f, "Constraint {}", constraint),
         }
     }
 }

third_party/move/move-bytecode-verifier/src/signature_v2.rs

@@ -98,7 +98,11 @@ impl<const N: usize> BitsetTypeParameterConstraints<N> {
     fn check_in_context(&self, context: &Self) -> PartialVMResult<()> {
         for i in 0..N {
             if self.words[i] | context.words[i] != context.words[i] {
-                return Err(PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED));
+                return Err(PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED)
+                    .with_message(format!(
+                        "expected abilities {:?} got abilities {:?}",
+                        self.words[i], context.words[i]
+                    )));
             }
         }
 

third_party/move/move-compiler/src/unit_test/mod.rs

@@ -166,6 +166,7 @@ impl<'a> fmt::Display for ExpectedMoveErrorDisplay<'a> {
             Location::Undefined => write!(f, " in an unknown location"),
             Location::Script => write!(f, " in the script"),
             Location::Module(id) => write!(f, " in the module {id}"),
+            Location::Constraint(constraint) => write!(f, " w.r.t. the constraint {constraint}"),
         }
     }
 }

third_party/move/move-vm/types/src/loaded_data/runtime_types.rs

@@ -326,7 +326,11 @@ impl Type {
         }
         for (ty, expected_ability_set) in ty_args.iter().zip(ty_param_abilities) {
             if !expected_ability_set.is_subset(ty.abilities()?) {
-                return Err(PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED));
+                return Err(PartialVMError::new(StatusCode::CONSTRAINT_NOT_SATISFIED)
+                    .with_message(format!(
+                        "type {} does not satisfy the expected abilities set {}",
+                        ty, expected_ability_set
+                    )));
             }
         }
         Ok(())
@@ -546,11 +550,11 @@ impl Type {
                 "Unexpected TyParam type after translating from TypeTag to Type".to_string(),
             )),
 
-            Type::Vector(ty) => {
-                AbilitySet::polymorphic_abilities(AbilitySet::VECTOR, vec![false], vec![
-                    ty.abilities()?
-                ])
-            },
+            Type::Vector(ty) => AbilitySet::polymorphic_abilities(
+                AbilitySet::VECTOR,
+                vec![false],
+                vec![ty.abilities()?],
+            ),
             Type::Struct { ability, .. } => Ok(ability.base_ability_set),
             Type::StructInstantiation {
                 ty_args,