charon_lib/ast/
ullbc_ast.rs

1//! "Unstructured LLBC" ast (ULLBC). This is LLBC before the control-flow
2//! reconstruction. In effect, this is a cleaned up version of MIR.
3pub use crate::ast::*;
4use derive_generic_visitor::{Drive, DriveMut};
5use macros::{EnumAsGetters, EnumIsA, VariantIndexArity, VariantName};
6use serde::{Deserialize, Serialize};
7
8// Block identifier. Similar to rust's `BasicBlock`.
9generate_index_type!(BlockId, "Block");
10
11// The entry block of a function is always the block with id 0
12pub static START_BLOCK_ID: BlockId = BlockId::ZERO;
13
14#[charon::rename("Blocks")]
15pub type BodyContents = Vector<BlockId, BlockData>;
16pub type ExprBody = GExprBody<BodyContents>;
17
18/// A raw statement: a statement without meta data.
19#[derive(
20    Debug, Clone, EnumIsA, EnumAsGetters, VariantName, Serialize, Deserialize, Drive, DriveMut,
21)]
22pub enum StatementKind {
23    Assign(Place, Rvalue),
24    /// A call. For now, we don't support dynamic calls (i.e. to a function pointer in memory).
25    SetDiscriminant(Place, VariantId),
26    /// Equivalent to std::intrinsics::copy_nonoverlapping; this is not modelled as a function
27    /// call as it cannot diverge
28    CopyNonOverlapping(Box<CopyNonOverlapping>),
29    /// Indicates that this local should be allocated; if it is already allocated, this frees
30    /// the local and re-allocates it. The return value and arguments do not receive a
31    /// `StorageLive`. We ensure in the micro-pass `insert_storage_lives` that all other locals
32    /// have a `StorageLive` associated with them.
33    StorageLive(LocalId),
34    /// Indicates that this local should be deallocated; if it is already deallocated, this is
35    /// a no-op. A local may not have a `StorageDead` in the function's body, in which case it
36    /// is implicitly deallocated at the end of the function.
37    StorageDead(LocalId),
38    Deinit(Place),
39    /// Drop the value at the given place.
40    ///
41    /// This calls `<T as Drop>::drop_in_place(&raw mut place)` and marks the place as
42    /// moved-out-of. The `drop_in_place` method is added by Charon, it contains the same code as
43    /// the `core::ptr::drop_in_place<T>` builtin).
44    Drop(Place, TraitRef),
45    /// A built-in assert, which corresponds to runtime checks that we remove, namely: bounds
46    /// checks, over/underflow checks, div/rem by zero checks, pointer alignement check.
47    Assert(Assert),
48    /// Does nothing. Useful for passes.
49    Nop,
50    #[charon::opaque]
51    #[drive(skip)]
52    Error(String),
53}
54
55#[derive(Debug, Clone, Serialize, Deserialize, Drive, DriveMut)]
56pub struct Statement {
57    pub span: Span,
58    pub kind: StatementKind,
59    /// Comments that precede this statement.
60    // This is filled in a late pass after all the control-flow manipulation.
61    #[drive(skip)]
62    pub comments_before: Vec<String>,
63}
64
65#[derive(
66    Debug,
67    Clone,
68    EnumIsA,
69    EnumAsGetters,
70    VariantName,
71    VariantIndexArity,
72    Serialize,
73    Deserialize,
74    Drive,
75    DriveMut,
76)]
77#[charon::rename("Switch")]
78pub enum SwitchTargets {
79    /// Gives the `if` block and the `else` block
80    If(BlockId, BlockId),
81    /// Gives the integer type, a map linking values to switch branches, and the
82    /// otherwise block. Note that matches over enumerations are performed by
83    /// switching over the discriminant, which is an integer.
84    SwitchInt(LiteralTy, Vec<(Literal, BlockId)>, BlockId),
85}
86
87/// A raw terminator: a terminator without meta data.
88#[derive(Debug, Clone, EnumIsA, EnumAsGetters, Serialize, Deserialize, Drive, DriveMut)]
89pub enum TerminatorKind {
90    Goto {
91        target: BlockId,
92    },
93    Switch {
94        discr: Operand,
95        targets: SwitchTargets,
96    },
97    Call {
98        call: Call,
99        target: BlockId,
100        on_unwind: BlockId,
101    },
102    /// Handles panics and impossible cases.
103    Abort(AbortKind),
104    Return,
105    UnwindResume,
106}
107
108#[derive(Debug, Clone, Serialize, Deserialize, Drive, DriveMut)]
109pub struct Terminator {
110    pub span: Span,
111    pub kind: TerminatorKind,
112    /// Comments that precede this terminator.
113    // This is filled in a late pass after all the control-flow manipulation.
114    #[drive(skip)]
115    pub comments_before: Vec<String>,
116}
117
118#[derive(Debug, Clone, Serialize, Deserialize, Drive, DriveMut)]
119#[charon::rename("Block")]
120pub struct BlockData {
121    pub statements: Vec<Statement>,
122    pub terminator: Terminator,
123}
charon_lib/ast/ullbc_ast.rs

charon_lib/ast/
ullbc_ast.rs
