charon_lib/ast/
llbc_ast.rs

1//! LLBC
2//!
3//! MIR code where we have rebuilt the control-flow (`if ... then ... else ...`,
4//! `while ...`, ...).
5//!
6//! Also note that we completely break the definitions Statement and Terminator
7//! from MIR to use Statement only.
8
9pub use super::llbc_ast_utils::*;
10pub use crate::ast::*;
11use derive_generic_visitor::{Drive, DriveMut};
12use macros::{EnumAsGetters, EnumIsA, EnumToGetters, VariantIndexArity, VariantName};
13use serde::{Deserialize, Serialize};
14
15/// A raw statement: a statement without meta data.
16#[derive(
17    Debug, Clone, EnumIsA, EnumToGetters, EnumAsGetters, Serialize, Deserialize, Drive, DriveMut,
18)]
19pub enum RawStatement {
20    /// Assigns an `Rvalue` to a `Place`. e.g. `let y = x;` could become
21    /// `y := move x` which is represented as `Assign(y, Rvalue::Use(Operand::Move(x)))`.
22    Assign(Place, Rvalue),
23    /// Not used today because we take MIR built.
24    SetDiscriminant(Place, VariantId),
25    /// Indicates that this local should be allocated; if it is already allocated, this frees
26    /// the local and re-allocates it. The return value and arguments do not receive a
27    /// `StorageLive`. We ensure in the micro-pass `insert_storage_lives` that all other locals
28    /// have a `StorageLive` associated with them.
29    StorageLive(LocalId),
30    /// Indicates that this local should be deallocated; if it is already deallocated, this is
31    /// a no-op. A local may not have a `StorageDead` in the function's body, in which case it
32    /// is implicitly deallocated at the end of the function.
33    StorageDead(LocalId),
34    Deinit(Place),
35    Drop(Place),
36    Assert(Assert),
37    Call(Call),
38    /// Panic also handles "unreachable". We keep the name of the panicking function that was
39    /// called.
40    Abort(AbortKind),
41    Return,
42    /// Break to outer loops.
43    /// The `usize` gives the index of the outer loop to break to:
44    /// * 0: break to first outer loop (the current loop)
45    /// * 1: break to second outer loop
46    /// * ...
47    #[drive(skip)]
48    Break(usize),
49    /// Continue to outer loops.
50    /// The `usize` gives the index of the outer loop to continue to:
51    /// * 0: continue to first outer loop (the current loop)
52    /// * 1: continue to second outer loop
53    /// * ...
54    #[drive(skip)]
55    Continue(usize),
56    /// No-op.
57    Nop,
58    Switch(Switch),
59    Loop(Block),
60    #[drive(skip)]
61    Error(String),
62}
63
64#[derive(Debug, Clone, Serialize, Deserialize, Drive, DriveMut)]
65pub struct Statement {
66    pub span: Span,
67    pub content: RawStatement,
68    /// Comments that precede this statement.
69    // This is filled in a late pass after all the control-flow manipulation.
70    #[drive(skip)]
71    pub comments_before: Vec<String>,
72}
73
74#[derive(Debug, Clone, Serialize, Deserialize, Drive, DriveMut)]
75pub struct Block {
76    pub span: Span,
77    pub statements: Vec<Statement>,
78}
79
80#[derive(
81    Debug,
82    Clone,
83    EnumIsA,
84    EnumToGetters,
85    EnumAsGetters,
86    Serialize,
87    Deserialize,
88    Drive,
89    DriveMut,
90    VariantName,
91    VariantIndexArity,
92)]
93pub enum Switch {
94    /// Gives the `if` block and the `else` block. The `Operand` is the condition of the `if`, e.g. `if (y == 0)` could become
95    /// ```rust,ignore
96    /// v@3 := copy y; // Represented as `Assign(v@3, Use(Copy(y))`
97    /// v@2 := move v@3 == 0; // Represented as `Assign(v@2, BinOp(BinOp::Eq, Move(y), Const(0)))`
98    /// if (move v@2) { // Represented as `If(Move(v@2), <then branch>, <else branch>)`
99    /// ```
100    If(Operand, Block, Block),
101    /// Gives the integer type, a map linking values to switch branches, and the
102    /// otherwise block. Note that matches over enumerations are performed by
103    /// switching over the discriminant, which is an integer.
104    /// Also, we use a `Vec` to make sure the order of the switch
105    /// branches is preserved.
106    ///
107    /// Rk.: we use a vector of values, because some of the branches may
108    /// be grouped together, like for the following code:
109    /// ```text
110    /// match e {
111    ///   E::V1 | E::V2 => ..., // Grouped
112    ///   E::V3 => ...
113    /// }
114    /// ```
115    SwitchInt(Operand, IntegerTy, Vec<(Vec<ScalarValue>, Block)>, Block),
116    /// A match over an ADT.
117    ///
118    /// The match statement is introduced in [crate::remove_read_discriminant]
119    /// (whenever we find a discriminant read, we merge it with the subsequent
120    /// switch into a match).
121    Match(Place, Vec<(Vec<VariantId>, Block)>, Option<Block>),
122}
123
124pub type ExprBody = GExprBody<Block>;
charon_lib/ast/llbc_ast.rs

charon_lib/ast/
llbc_ast.rs
