cairo-lang-lowering 2.17.0

//! > Test panic.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo(x: felt252) {
    bar(@x)
}

//! > function_name
foo

//! > module_code
extern fn bar(x: @felt252) nopanic;

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: core::felt252
blk0 (root):
Statements:
  (v1: core::felt252, v2: @core::felt252) <- snapshot(v0)
  () <- test::bar(v2)
End:
  Return()

//! > ==========================================================================

//! > Test struct snapshot.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo(orig: @A) -> @A {
    bar(orig.a, orig.b);
    let A { a, b } = orig;
    bar(a, b);
    orig
}

//! > function_name
foo

//! > module_code
struct A {
    a: Array<felt252>,
    b: felt252,
}
#[inline(never)]
fn bar(a: @Array::<felt252>, b: @felt252) {}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: @test::A
blk0 (root):
Statements:
  (v1: @core::array::Array::<core::felt252>, v2: @core::felt252) <- struct_destructure(v0)
  () <- test::bar(v1, v2)
  () <- test::bar(v1, v2)
End:
  Return(v0)

//! > ==========================================================================

//! > Test enum snapshot.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo(orig: @A) -> @A {
    match orig {
        A::A(a) => bar0(a),
        A::B(b) => bar1(b),
        A::C((c, d)) => bar2(c, d),
    }
    orig
}

//! > function_name
foo

//! > module_code
enum A {
    A: Array<felt252>,
    B: felt252,
    C: (felt252, Array::<felt252>),
}
#[inline(never)]
fn bar0(a: @Array::<felt252>) {}
#[inline(never)]
fn bar1(b: @felt252) {}
#[inline(never)]
fn bar2(c: @felt252, d: @Array::<felt252>) {}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: @test::A
blk0 (root):
Statements:
End:
  Match(match_enum(v0) {
    A::A(v1) => blk1,
    A::B(v2) => blk2,
    A::C(v3) => blk3,
  })

blk1:
Statements:
  () <- test::bar0(v1)
End:
  Return(v0)

blk2:
Statements:
  () <- test::bar1(v2)
End:
  Return(v0)

blk3:
Statements:
  (v4: @core::felt252, v5: @core::array::Array::<core::felt252>) <- struct_destructure(v3)
  () <- test::bar2(v4, v5)
End:
  Return(v0)

//! > ==========================================================================

//! > Test felt252 desnap.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo(value: @felt252) -> felt252 {
    *value
}

//! > function_name
foo

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: @core::felt252
blk0 (root):
Statements:
  (v1: core::felt252) <- desnap(v0)
End:
  Return(v1)

//! > ==========================================================================

//! > Test array desnap.

//! > test_runner_name
test_function_lowering(expect_diagnostics: true)

//! > function_code
fn foo(value: @Array::<felt252>) -> Array<felt252> {
    *value
}

//! > function_name
foo

//! > semantic_diagnostics

//! > lowering_diagnostics
error[E3003]: Cannot desnap a non copyable type.
 --> lib.cairo:2:5
    *value
    ^^^^^^
note: Trait has no implementation in context: core::traits::Copy::<core::array::Array::<core::felt252>>.

//! > lowering_flat
<Failed lowering function - run with RUST_LOG=warn (or less) to see diagnostics>

//! > ==========================================================================

//! > Test member snapshot

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo(a: A) -> usize {
    bar(@a.b);
    a.b
}

//! > function_name
foo

//! > module_code
struct A {
    b: usize,
}
extern fn bar(x: @usize) nopanic;

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: test::A
blk0 (root):
Statements:
  (v1: core::integer::u32) <- struct_destructure(v0)
  (v2: core::integer::u32, v3: @core::integer::u32) <- snapshot(v1)
  () <- test::bar(v3)
End:
  Return(v2)

//! > ==========================================================================

//! > Test snapshot invalidation full var.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo() -> usize {
    let mut array: Array<u32> = array![14];
    let mut i = 0;

    while i < array.len() {
        i += 1;
    }

    array.pop_front().unwrap();

    array.len()
}

//! > function_name
foo

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: core::RangeCheck, v1: core::gas::GasBuiltin
blk0 (root):
Statements:
  (v2: core::RangeCheck, v3: core::gas::GasBuiltin, v4: core::panics::PanicResult::<(core::integer::u32, ())>) <- test::foo[83-134]{0, @array![14], }(v0, v1)
End:
  Match(match_enum(v4) {
    PanicResult::Ok(v5) => blk1,
    PanicResult::Err(v6) => blk4,
  })

blk1:
Statements:
  (v7: core::array::Array::<core::integer::u32>) <- core::array::array_new::<core::integer::u32>()
  (v8: core::integer::u32) <- 14
  (v9: core::array::Array::<core::integer::u32>) <- core::array::array_append::<core::integer::u32>(v7, v8)
End:
  Match(match core::array::array_pop_front::<core::integer::u32>(v9) {
    Option::Some(v10, v11) => blk2,
    Option::None(v12) => blk3,
  })

blk2:
Statements:
  (v13: core::gas::GasBuiltin) <- core::gas::redeposit_gas(v3)
  (v14: core::array::Array::<core::integer::u32>, v15: @core::array::Array::<core::integer::u32>) <- snapshot(v10)
  (v16: core::integer::u32) <- core::array::array_len::<core::integer::u32>(v15)
  (v17: (core::integer::u32,)) <- struct_construct(v16)
  (v18: core::panics::PanicResult::<(core::integer::u32,)>) <- PanicResult::Ok(v17)
End:
  Return(v2, v13, v18)

blk3:
Statements:
  (v19: (core::panics::Panic, core::array::Array::<core::felt252>)) <- core::panic_with_const_felt252::<29721761890975875353235833581453094220424382983267374>()
  (v20: core::panics::PanicResult::<(core::integer::u32,)>) <- PanicResult::Err(v19)
End:
  Return(v2, v3, v20)

blk4:
Statements:
  (v21: core::panics::PanicResult::<(core::integer::u32,)>) <- PanicResult::Err(v6)
End:
  Return(v2, v3, v21)

//! > ==========================================================================

//! > Test snapshot invalidation partial var.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo() -> @u8 {
    let mut a = A { b: 8 };
    loop {
        let _v = @(a.b);
        break;
    }
    a = A { b: 7 };

    @(a.b)
}

//! > function_name
foo

//! > module_code
#[derive(Drop)]
struct A {
    b: u8,
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters:
blk0 (root):
Statements:
  (v0: core::integer::u8) <- 7
  (v1: core::integer::u8, v2: @core::integer::u8) <- snapshot(v0)
End:
  Return(v2)

//! > ==========================================================================

//! > Test snapshot use same snapshot inner loop.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo() {
    let a = A { b: 7 };
    loop {
        let _ = @a;
        loop {
            let _ = @a;
            break;
        }
        break;
    }
}

//! > function_name
foo

//! > module_code
#[derive(Drop)]
struct A {
    b: u8,
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters:
blk0 (root):
Statements:
End:
  Return()

//! > ==========================================================================

//! > Test snapshot of overridden member.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo() -> @A {
    let mut a = A { m: 7 };
    let _z = @a;
    a.m = 0;
    @a
}

//! > function_name
foo

//! > module_code
#[derive(Copy, Drop)]
struct A {
    m: u8,
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters:
blk0 (root):
Statements:
  (v0: core::integer::u8) <- 0
  (v1: test::A) <- struct_construct(v0)
  (v2: test::A, v3: @test::A) <- snapshot(v1)
End:
  Return(v3)

//! > ==========================================================================

//! > Test snapshot of overridden parent.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > function_code
fn foo() -> @u8 {
    let mut a = A { m: Member { m: 7 } };
    let _z = @a.m.m;
    a.m = Member { m: 0 };
    @a.m.m
}

//! > function_name
foo

//! > module_code
#[derive(Copy, Drop)]
struct A {
    m: Member,
}

#[derive(Copy, Drop)]
struct Member {
    m: u8,
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters:
blk0 (root):
Statements:
  (v0: core::integer::u8) <- 0
  (v1: core::integer::u8, v2: @core::integer::u8) <- snapshot(v0)
End:
  Return(v2)

//! > ==========================================================================

//! > Test struct snapshot auto member access desnap.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > crate_settings
edition = "2025_12"

//! > function_code
fn foo(
    a: @A,
) -> (@Array<felt252>, @Array<felt252>, @@Array<felt252>, felt252, @felt252, @felt252, @@felt252) {
    (@a.a, @(@a).a, @@(@a).a, a.b, @a.b, @(@a).b, @@(@a).b)
}

//! > function_name
foo

//! > module_code
struct A {
    a: Array<felt252>,
    b: felt252,
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: @test::A
blk0 (root):
Statements:
  (v1: @test::A, v2: @@test::A) <- snapshot(v0)
  (v3: @@core::array::Array::<core::felt252>, v4: @@core::felt252) <- struct_destructure(v2)
  (v5: @core::array::Array::<core::felt252>, v6: @core::felt252) <- struct_destructure(v0)
  (v7: @core::array::Array::<core::felt252>) <- desnap(v3)
  (v8: core::felt252) <- desnap(v6)
  (v9: @core::felt252) <- desnap(v4)
  (v10: (@core::array::Array::<core::felt252>, @core::array::Array::<core::felt252>, @@core::array::Array::<core::felt252>, core::felt252, @core::felt252, @core::felt252, @@core::felt252)) <- struct_construct(v5, v7, v3, v8, v6, v9, v4)
End:
  Return(v10)