feat: add printing hints (#1476)

* add print hints

* test

* remove u256 add felt

* change log

* fix based on comments

* add std feature for print

* Move Cairo Programs

* Update Makefile

* Use print tag  in test

* cargo fmt

* Update Makefile

* Update Makefile

---------

Co-authored-by: Pedro Fontana <[email protected]>

CHANGELOG.md

@@ -2,8 +2,11 @@
 
 #### Upcoming Changes
 
+* feat: add debugging capabilities behind `print` feature flag. [#1476](https://github.com/lambdaclass/cairo-vm/pull/1476)
+
 #### [0.9.1] - 2023-11-16
 
+
 * chore: bump `cairo-lang-` dependencies to 2.3.1 [#1482](https://github.com/lambdaclass/cairo-vm/pull/1482), [#1483](https://github.com/lambdaclass/cairo-vm/pull/1483)
 
 * feat: Make PublicInput fields public [#1474](https://github.com/lambdaclass/cairo-vm/pull/1474)

Makefile

@@ -73,6 +73,9 @@ BAD_TEST_DIR=cairo_programs/bad_programs
 BAD_TEST_FILES:=$(wildcard $(BAD_TEST_DIR)/*.cairo)
 COMPILED_BAD_TESTS:=$(patsubst $(BAD_TEST_DIR)/%.cairo, $(BAD_TEST_DIR)/%.json, $(BAD_TEST_FILES))
 
+PRINT_TEST_DIR=cairo_programs/print_feature
+PRINT_TEST_FILES:=$(wildcard $(PRINT_TEST_DIR)/*.cairo)
+COMPILED_PRINT_TESTS:=$(patsubst $(PRINT_TEST_DIR)/%.cairo, $(PRINT_TEST_DIR)/%.json, $(PRINT_TEST_FILES))
 
 NORETROCOMPAT_DIR:=cairo_programs/noretrocompat
 NORETROCOMPAT_FILES:=$(wildcard $(NORETROCOMPAT_DIR)/*.cairo)
@@ -96,6 +99,9 @@ $(NORETROCOMPAT_DIR)/%.json: $(NORETROCOMPAT_DIR)/%.cairo
 $(BAD_TEST_DIR)/%.json: $(BAD_TEST_DIR)/%.cairo
 	cairo-compile $< --output $@
 
+$(PRINT_TEST_DIR)/%.json: $(PRINT_TEST_DIR)/%.cairo
+	cairo-compile $< --output $@
+
 # ======================
 # Test Cairo 1 Contracts
 # ======================
@@ -212,7 +218,7 @@ run:
 check:
 	cargo check
 
-cairo_test_programs: $(COMPILED_TESTS) $(COMPILED_BAD_TESTS) $(COMPILED_NORETROCOMPAT_TESTS)
+cairo_test_programs: $(COMPILED_TESTS) $(COMPILED_BAD_TESTS) $(COMPILED_NORETROCOMPAT_TESTS) $(COMPILED_PRINT_TESTS)
 cairo_proof_programs: $(COMPILED_PROOF_TESTS)
 cairo_bench_programs: $(COMPILED_BENCHES)
 cairo_1_test_contracts: $(CAIRO_1_COMPILED_CASM_CONTRACTS)
@@ -296,6 +302,7 @@ clean:
 	rm -f $(TEST_DIR)/*.trace
 	rm -f $(BENCH_DIR)/*.json
 	rm -f $(BAD_TEST_DIR)/*.json
+	rm -f $(PRINT_TEST_DIR)/*.json
 	rm -f $(CAIRO_1_CONTRACTS_TEST_DIR)/*.sierra
 	rm -f $(CAIRO_1_CONTRACTS_TEST_DIR)/*.casm
 	rm -f $(TEST_PROOF_DIR)/*.json

cairo_programs/print_feature/print_array.cairo

@@ -0,0 +1,20 @@
+%builtins range_check
+
+from starkware.cairo.common.alloc import alloc
+
+func main{range_check_ptr: felt}() {
+    let name = 0x4b4b5254;
+    let (arr: felt*) = alloc();
+    assert arr[0] = 1;
+    assert arr[1] = 2;
+    assert arr[2] = 3;
+    assert arr[3] = 4;
+    assert arr[4] = 5;
+    let arr_len = 5;
+    %{
+        print(bytes.fromhex(f"{ids.name:062x}").decode().replace('\x00',''))
+        arr = [memory[ids.arr + i] for i in range(ids.arr_len)]
+        print(arr)
+    %}
+    return();
+}

cairo_programs/print_feature/print_dict_array.cairo

@@ -0,0 +1,34 @@
+%builtins range_check
+
+from starkware.cairo.common.dict_access import DictAccess
+from starkware.cairo.common.default_dict import default_dict_new, default_dict_finalize
+from starkware.cairo.common.dict import dict_write
+
+struct MyStruct {
+    a: felt,
+    b: felt, 
+    c: felt,
+}
+
+func main{range_check_ptr: felt}() {
+    let name = 0x4b4b5254;
+    let (dict_ptr) = default_dict_new(0);
+    let pointer_size = 3;
+
+    tempvar one = new MyStruct(1,2,3);
+    dict_write{dict_ptr=dict_ptr}(0, cast(one, felt));
+    tempvar two = new MyStruct(2,3,4);
+    dict_write{dict_ptr=dict_ptr}(1, cast(two, felt));
+    tempvar three = new MyStruct(3,4,5);
+    dict_write{dict_ptr=dict_ptr}(2, cast(three, felt));
+    tempvar four = new MyStruct(4,5,6);
+    dict_write{dict_ptr=dict_ptr}(3, cast(four, felt));
+    %{
+        print(bytes.fromhex(f"{ids.name:062x}").decode().replace('\x00',''))
+        data = __dict_manager.get_dict(ids.dict_ptr)
+        print(
+            {k: v if isinstance(v, int) else [memory[v + i] for i in range(ids.pointer_size)] for k, v in data.items()}
+        )
+    %}
+    return();
+}

cairo_programs/print_feature/print_dict_felt.cairo

@@ -0,0 +1,24 @@
+%builtins range_check
+
+from starkware.cairo.common.dict_access import DictAccess
+from starkware.cairo.common.default_dict import default_dict_new, default_dict_finalize
+from starkware.cairo.common.dict import dict_write
+
+func main{range_check_ptr: felt}() {
+    let name = 0x4b4b5254;
+    let (dict_ptr) = default_dict_new(0);
+    let pointer_size = 1;
+    dict_write{dict_ptr=dict_ptr}(0, 1);
+    dict_write{dict_ptr=dict_ptr}(1, 2);
+    dict_write{dict_ptr=dict_ptr}(2, 3);
+    dict_write{dict_ptr=dict_ptr}(3, 4);
+    dict_write{dict_ptr=dict_ptr}(4, 5);
+    %{
+        print(bytes.fromhex(f"{ids.name:062x}").decode().replace('\x00',''))
+        data = __dict_manager.get_dict(ids.dict_ptr)
+        print(
+            {k: v if isinstance(v, int) else [memory[v + i] for i in range(ids.pointer_size)] for k, v in data.items()}
+        )
+    %}
+    return();
+}

cairo_programs/print_feature/print_felt.cairo

@@ -0,0 +1,9 @@
+%builtins range_check
+
+func main{range_check_ptr: felt}() {
+    let x = 123;
+    %{
+        print(ids.x)
+    %}
+    return();
+}

vm/Cargo.toml

@@ -33,9 +33,11 @@ lambdaworks-felt = ["felt/lambdaworks-felt"]
 test_utils = [
     "skip_next_instruction_hint",
     "hooks",
+    "print",
 ] # This feature will reference every test-oriented feature
 skip_next_instruction_hint = []
 hooks = []
+print = ["std"]
 
 [dependencies]
 mimalloc = { workspace = true, optional = true }

vm/src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs

@@ -116,6 +116,9 @@ use felt::Felt252;
 #[cfg(feature = "skip_next_instruction_hint")]
 use crate::hint_processor::builtin_hint_processor::skip_next_instruction::skip_next_instruction;
 
+#[cfg(feature = "print")]
+use crate::hint_processor::builtin_hint_processor::print::{print_array, print_dict, print_felt};
+
 use super::blake2s_utils::example_blake2s_compress;
 
 pub struct HintProcessorData {
@@ -815,6 +818,14 @@ impl HintProcessorLogic for BuiltinHintProcessor {
             hint_code::SPLIT_XX => split_xx(vm, &hint_data.ids_data, &hint_data.ap_tracking),
             #[cfg(feature = "skip_next_instruction_hint")]
             hint_code::SKIP_NEXT_INSTRUCTION => skip_next_instruction(vm),
+            #[cfg(feature = "print")]
+            hint_code::PRINT_FELT => print_felt(vm, &hint_data.ids_data, &hint_data.ap_tracking),
+            #[cfg(feature = "print")]
+            hint_code::PRINT_ARR => print_array(vm, &hint_data.ids_data, &hint_data.ap_tracking),
+            #[cfg(feature = "print")]
+            hint_code::PRINT_DICT => {
+                print_dict(vm, exec_scopes, &hint_data.ids_data, &hint_data.ap_tracking)
+            }
             code => Err(HintError::UnknownHint(code.to_string().into_boxed_str())),
         }
     }

vm/src/hint_processor/builtin_hint_processor/hint_code.rs

@@ -1409,3 +1409,15 @@ ids.x.low = x & ((1<<128)-1)
 ids.x.high = x >> 128";
 #[cfg(feature = "skip_next_instruction_hint")]
 pub const SKIP_NEXT_INSTRUCTION: &str = "skip_next_instruction()";
+
+pub const PRINT_FELT: &str = "print(ids.x)";
+
+pub const PRINT_ARR: &str = r#"print(bytes.fromhex(f"{ids.name:062x}").decode().replace('\x00',''))
+arr = [memory[ids.arr + i] for i in range(ids.arr_len)]
+print(arr)"#;
+
+pub const PRINT_DICT: &str = r#"print(bytes.fromhex(f"{ids.name:062x}").decode().replace('\x00',''))
+data = __dict_manager.get_dict(ids.dict_ptr)
+print(
+    {k: v if isinstance(v, int) else [memory[v + i] for i in range(ids.pointer_size)] for k, v in data.items()}
+)"#;

vm/src/hint_processor/builtin_hint_processor/mod.rs

@@ -18,6 +18,8 @@ pub mod memcpy_hint_utils;
 pub mod memset_utils;
 pub mod poseidon_utils;
 pub mod pow_utils;
+#[cfg(feature = "print")]
+pub mod print;
 pub mod secp;
 pub mod segments;
 pub mod set;

vm/src/hint_processor/builtin_hint_processor/print.rs

@@ -0,0 +1,124 @@
+use core::fmt::{Debug, Formatter};
+
+use felt::Felt252;
+use num_traits::ToPrimitive;
+
+use crate::hint_processor::builtin_hint_processor::dict_manager::Dictionary;
+use crate::hint_processor::builtin_hint_processor::hint_utils::{
+    get_integer_from_var_name, get_ptr_from_var_name,
+};
+use crate::serde::deserialize_program::ApTracking;
+use crate::stdlib::collections::HashMap;
+
+use crate::types::exec_scope::ExecutionScopes;
+use crate::types::relocatable::MaybeRelocatable;
+use crate::vm::errors::hint_errors::HintError;
+use crate::{
+    hint_processor::hint_processor_definition::HintReference, vm::vm_core::VirtualMachine,
+};
+
+pub fn print_felt(
+    vm: &VirtualMachine,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+) -> Result<(), HintError> {
+    let val = get_integer_from_var_name("x", vm, ids_data, ap_tracking)?;
+    println!("{val}");
+    Ok(())
+}
+
+fn print_name(
+    vm: &VirtualMachine,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+) -> Result<(), HintError> {
+    let name = get_integer_from_var_name("name", vm, ids_data, ap_tracking)?;
+    let name = String::from_utf8(name.to_bigint().to_signed_bytes_be())
+        .map_err(|err| HintError::CustomHint(err.to_string().into_boxed_str()))?;
+    println!("{name}");
+    Ok(())
+}
+
+pub fn print_array(
+    vm: &VirtualMachine,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+) -> Result<(), HintError> {
+    print_name(vm, ids_data, ap_tracking)?;
+
+    let mut acc = Vec::new();
+    let arr = get_ptr_from_var_name("arr", vm, ids_data, ap_tracking)?;
+    let arr_len = get_integer_from_var_name("arr_len", vm, ids_data, ap_tracking)?;
+    let arr_len = arr_len.to_usize().ok_or_else(|| {
+        HintError::CustomHint(String::from("arr_len must be a positive integer").into_boxed_str())
+    })?;
+    for i in 0..arr_len {
+        let val = vm.get_integer((arr + i)?)?;
+        acc.push(val);
+    }
+    println!("{:?}", acc);
+    Ok(())
+}
+
+enum DictValue {
+    Int(Felt252),
+    Relocatable(Vec<Felt252>),
+}
+
+impl Debug for DictValue {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::Int(int) => write!(f, "{:?}", int),
+            Self::Relocatable(relocatable) => write!(f, "{:?}", relocatable),
+        }
+    }
+}
+
+pub fn print_dict(
+    vm: &VirtualMachine,
+    exec_scopes: &ExecutionScopes,
+    ids_data: &HashMap<String, HintReference>,
+    ap_tracking: &ApTracking,
+) -> Result<(), HintError> {
+    print_name(vm, ids_data, ap_tracking)?;
+
+    let dict_ptr = get_ptr_from_var_name("dict_ptr", vm, ids_data, ap_tracking)?;
+    let pointer_size = get_integer_from_var_name("pointer_size", vm, ids_data, ap_tracking)?;
+    let pointer_size = pointer_size.to_usize().ok_or_else(|| {
+        HintError::CustomHint(
+            String::from("pointer_size must be a positive integer").into_boxed_str(),
+        )
+    })?;
+
+    let dict_manager = exec_scopes.get_dict_manager()?;
+    let dict_manager = dict_manager.borrow();
+    let tracker = dict_manager.get_tracker(dict_ptr)?;
+
+    let map = match &tracker.data {
+        Dictionary::SimpleDictionary(dict) => dict,
+        Dictionary::DefaultDictionary { dict, .. } => dict,
+    };
+
+    let mut acc = HashMap::new();
+    for (k, v) in map.iter() {
+        let key = k.get_int_ref().ok_or_else(|| {
+            HintError::CustomHint(String::from("Expected felt key for dict").into_boxed_str())
+        })?;
+        match v {
+            MaybeRelocatable::Int(value) => {
+                acc.insert(key, DictValue::Int(value.clone()));
+            }
+            MaybeRelocatable::RelocatableValue(val) => {
+                let mut structure = Vec::new();
+                for i in 0..pointer_size {
+                    let val = vm.get_integer((*val + i)?)?.as_ref().clone();
+                    structure.push(val);
+                }
+                acc.insert(key, DictValue::Relocatable(structure));
+            }
+        }
+    }
+
+    println!("{:?}", acc);
+    Ok(())
+}

vm/src/tests/cairo_run_test.rs

@@ -1032,3 +1032,32 @@ fn divmod_igcdex_not_one() {
     let error_msg = "Operation failed: divmod(1, 340282366920938463463374607431768211457, 340282366920938463463374607431768211457), igcdex(340282366920938463463374607431768211457, 340282366920938463463374607431768211457) != 1";
     run_program_with_error(program_data.as_slice(), error_msg);
 }
+
+#[test]
+#[cfg(feature = "print")]
+fn cairo_run_print_felt() {
+    let program_data = include_bytes!("../../../cairo_programs/print_feature/print_felt.json");
+    run_program_simple(program_data);
+}
+
+#[test]
+#[cfg(feature = "print")]
+fn cairo_run_print_array() {
+    let program_data = include_bytes!("../../../cairo_programs/print_feature/print_array.json");
+    run_program_simple(program_data);
+}
+
+#[test]
+#[cfg(feature = "print")]
+fn cairo_run_print_dict_felt() {
+    let program_data = include_bytes!("../../../cairo_programs/print_feature/print_dict_felt.json");
+    run_program_simple_with_memory_holes(program_data, 5);
+}
+
+#[test]
+#[cfg(feature = "print")]
+fn cairo_run_print_dict_array() {
+    let program_data =
+        include_bytes!("../../../cairo_programs/print_feature/print_dict_array.json");
+    run_program_simple_with_memory_holes(program_data, 4);
+}