Merge pull request #4645 from starkware-libs/nimrod/hints/compiled_cl…

…ass/load_class

feat(starknet_os): implement load class hint

crates/starknet_os/src/hints/enum_definition.rs

@@ -361,6 +361,19 @@ define_hint_enum!(
         r#"memory[ap] = to_felt_or_relocatable(ids.request_block_number > \
            ids.current_block_number - ids.STORED_BLOCK_HASH_BUFFER)"#
     ),
+    (
+        LoadClass,
+        load_class,
+        indoc! {r#"
+    vm_exit_scope()
+
+    computed_hash = ids.hash
+    expected_hash = ids.compiled_class_fact.hash
+    assert computed_hash == expected_hash, (
+        "Computed compiled_class_hash is inconsistent with the hash in the os_input. "
+        f"Computed hash = {computed_hash}, Expected hash = {expected_hash}.")"#
+        }
+    ),
     (
         LoadClassInner,
         load_class_inner,
@@ -1760,19 +1773,6 @@ if da_path is not None:
 
 define_hint_extension_enum!(
     HintExtension,
-    (
-        LoadClass,
-        load_class,
-        indoc! {r#"
-    vm_exit_scope()
-
-    computed_hash = ids.hash
-    expected_hash = ids.compiled_class_fact.hash
-    assert computed_hash == expected_hash, (
-        "Computed compiled_class_hash is inconsistent with the hash in the os_input. "
-        f"Computed hash = {computed_hash}, Expected hash = {expected_hash}.")"#
-        }
-    ),
     (
         LoadDeprecatedClass,
         load_deprecated_class,

crates/starknet_os/src/hints/error.rs

@@ -2,6 +2,7 @@ use blockifier::state::errors::StateError;
 use cairo_vm::hint_processor::hint_processor_definition::HintExtension;
 use cairo_vm::serde::deserialize_program::Identifier;
 use cairo_vm::types::errors::math_errors::MathError;
+use cairo_vm::vm::errors::exec_scope_errors::ExecScopeError;
 use cairo_vm::vm::errors::hint_errors::HintError as VmHintError;
 use cairo_vm::vm::errors::memory_errors::MemoryError;
 use cairo_vm::vm::errors::vm_errors::VirtualMachineError;
@@ -20,31 +21,33 @@ pub enum OsHintError {
     BooleanIdExpected { id: Ids, felt: Felt },
     #[error("Failed to convert {variant:?} felt value {felt:?} to type {ty}: {reason:?}.")]
     ConstConversionError { variant: Const, felt: Felt, ty: String, reason: String },
+    #[error(transparent)]
+    ExecutionScopes(#[from] ExecScopeError),
+    #[error("The identifier {0:?} has no full name.")]
+    IdentifierHasNoFullName(Box<Identifier>),
+    #[error("The identifier {0:?} has no members.")]
+    IdentifierHasNoMembers(Box<Identifier>),
     #[error(
         "Inconsistent block numbers: {actual}, {expected}. The constant STORED_BLOCK_HASH_BUFFER \
          is probably out of sync."
     )]
     InconsistentBlockNumber { actual: BlockNumber, expected: BlockNumber },
+    #[error(transparent)]
+    MathError(#[from] MathError),
+    #[error(transparent)]
+    MemoryError(#[from] MemoryError),
     #[error("{error:?} for json value {value}.")]
     SerdeJsonError { error: serde_json::Error, value: serde_json::value::Value },
     #[error(transparent)]
     StateError(#[from] StateError),
-    #[error(transparent)]
-    VmError(#[from] VirtualMachineError),
-    #[error(transparent)]
-    VmHintError(#[from] VmHintError),
+    #[error("Convert {n_bits} bits for {type_name}.")]
+    StatelessCompressionOverflow { n_bits: usize, type_name: String },
     #[error("Unknown hint string: {0}")]
     UnknownHint(String),
-    #[error("The identifier {0:?} has no full name.")]
-    IdentifierHasNoFullName(Box<Identifier>),
-    #[error("The identifier {0:?} has no members.")]
-    IdentifierHasNoMembers(Box<Identifier>),
     #[error(transparent)]
-    MathError(#[from] MathError),
+    VmError(#[from] VirtualMachineError),
     #[error(transparent)]
-    MemoryError(#[from] MemoryError),
-    #[error("Convert {n_bits} bits for {type_name}.")]
-    StatelessCompressionOverflow { n_bits: usize, type_name: String },
+    VmHintError(#[from] VmHintError),
 }
 
 /// `OsHintError` and the VM's `HintError` must have conversions in both directions, as execution

crates/starknet_os/src/hints/hint_implementation/compiled_class.rs

@@ -1,7 +1,10 @@
 use blockifier::state::state_api::StateReader;
+use cairo_vm::hint_processor::builtin_hint_processor::hint_utils::get_integer_from_var_name;
 
-use crate::hints::error::{OsHintExtensionResult, OsHintResult};
+use crate::hints::error::{OsHintError, OsHintResult};
 use crate::hints::types::HintArgs;
+use crate::hints::vars::{CairoStruct, Ids};
+use crate::vm_utils::get_address_of_nested_fields;
 
 pub(crate) fn assign_bytecode_segments<S: StateReader>(
     HintArgs { .. }: HintArgs<'_, S>,
@@ -26,6 +29,32 @@ pub(crate) fn iter_current_segment_info<S: StateReader>(
     todo!()
 }
 
+pub(crate) fn load_class<S: StateReader>(
+    HintArgs { exec_scopes, ids_data, ap_tracking, vm, hint_processor, .. }: HintArgs<'_, S>,
+) -> OsHintResult {
+    exec_scopes.exit_scope()?;
+    let expected_hash_address = get_address_of_nested_fields(
+        ids_data,
+        Ids::CompiledClassFact,
+        CairoStruct::CompiledClassFact,
+        vm,
+        ap_tracking,
+        &["hash".to_string()],
+        &hint_processor.execution_helper.os_program,
+    )?;
+    let expected_hash = vm.get_integer(expected_hash_address)?;
+    let computed_hash = get_integer_from_var_name(Ids::Hash.into(), vm, ids_data, ap_tracking)?;
+    if &computed_hash != expected_hash.as_ref() {
+        return Err(OsHintError::AssertionFailed {
+            message: format!(
+                "Computed compiled_class_hash is inconsistent with the hash in the os_input. \
+                 Computed hash = {computed_hash}, Expected hash = {expected_hash}."
+            ),
+        });
+    }
+
+    Ok(())
+}
 pub(crate) fn load_class_inner<S: StateReader>(HintArgs { .. }: HintArgs<'_, S>) -> OsHintResult {
     todo!()
 }
@@ -41,11 +70,3 @@ pub(crate) fn validate_compiled_class_facts_post_execution<S: StateReader>(
 ) -> OsHintResult {
     todo!()
 }
-
-// Hint extension implementations.
-
-pub(crate) fn load_class<S: StateReader>(
-    HintArgs { .. }: HintArgs<'_, S>,
-) -> OsHintExtensionResult {
-    todo!()
-}

crates/starknet_os/src/hints/vars.rs

@@ -53,6 +53,7 @@ pub enum Ids {
     ContractStateChanges,
     DictPtr,
     FullOutput,
+    Hash,
     NCompiledClassFacts,
     NextAvailableAlias,
     OldBlockHash,
@@ -76,6 +77,7 @@ impl From<Ids> for &'static str {
             Ids::ContractStateChanges => "contract_state_changes",
             Ids::DictPtr => "dict_ptr",
             Ids::FullOutput => "full_output",
+            Ids::Hash => "hash",
             Ids::NCompiledClassFacts => "n_compiled_class_facts",
             Ids::NextAvailableAlias => "next_available_alias",
             Ids::OldBlockHash => "old_block_hash",
@@ -146,6 +148,7 @@ impl Const {
     }
 }
 pub enum CairoStruct {
+    CompiledClassFact,
     DeprecatedCompiledClass,
     DeprecatedCompiledClassFact,
     DictAccess,
@@ -155,6 +158,9 @@ pub enum CairoStruct {
 impl From<CairoStruct> for &'static str {
     fn from(struct_name: CairoStruct) -> Self {
         match struct_name {
+            CairoStruct::CompiledClassFact => {
+                "starkware.starknet.core.os.contract_class.compiled_class.CompiledClassFact"
+            }
             CairoStruct::DeprecatedCompiledClass => {
                 "starkware.starknet.core.os.contract_class.deprecated_compiled_class.\
                  DeprecatedCompiledClass"