Skip to main content

aver/codegen/
mod.rs

1/// Aver → target language transpilation.
2///
3/// The codegen module transforms a type-checked Aver AST into source code
4/// for a target language. Current backends: Rust deployment and Lean proof export.
5pub(crate) mod builtins;
6pub(crate) mod common;
7pub mod dafny;
8pub mod lean;
9pub mod rust;
10#[cfg(feature = "wasm")]
11pub mod wasm;
12
13use std::collections::{HashMap, HashSet};
14
15use crate::ast::{FnDef, TopLevel, TypeDef};
16use crate::types::checker::TypeCheckResult;
17
18/// Information about a dependent module loaded for codegen.
19pub struct ModuleInfo {
20    /// Qualified module path, e.g. "Models.User".
21    pub prefix: String,
22    /// Direct `depends [...]` entries from the source module.
23    pub depends: Vec<String>,
24    /// Type definitions from the module.
25    pub type_defs: Vec<TypeDef>,
26    /// Function definitions from the module (excluding `main`).
27    pub fn_defs: Vec<FnDef>,
28}
29
30/// Collected context from the Aver program, shared across all backends.
31pub struct CodegenContext {
32    /// All top-level items (post-TCO transform, post-typecheck).
33    pub items: Vec<TopLevel>,
34    /// Function signatures: name → (param_types, return_type, effects).
35    pub fn_sigs: HashMap<String, (Vec<crate::types::Type>, crate::types::Type, Vec<String>)>,
36    /// Functions eligible for auto-memoization.
37    pub memo_fns: HashSet<String>,
38    /// Set of type names whose values are memo-safe.
39    pub memo_safe_types: HashSet<String>,
40    /// User-defined type definitions (for struct/enum generation).
41    pub type_defs: Vec<TypeDef>,
42    /// User-defined function definitions.
43    pub fn_defs: Vec<FnDef>,
44    /// Project/binary name.
45    pub project_name: String,
46    /// Dependent modules loaded for inlining.
47    pub modules: Vec<ModuleInfo>,
48    /// Set of module prefixes for qualified name resolution (e.g. "Models.User").
49    pub module_prefixes: HashSet<String>,
50    /// Embedded runtime policy from `aver.toml` for generated code.
51    pub policy: Option<crate::config::ProjectConfig>,
52    /// Emit generated scoped runtime support (replay and/or runtime-loaded policy).
53    pub emit_replay_runtime: bool,
54    /// Load runtime policy from the active module root instead of embedding it.
55    pub runtime_policy_from_env: bool,
56    /// Explicit guest entry boundary for scoped replay/policy.
57    pub guest_entry: Option<String>,
58    /// Emit extra generated helpers needed only by the cached self-host helper.
59    pub emit_self_host_support: bool,
60    /// Extra fn_defs visible during current module emission (not in `fn_defs` or `modules`).
61    /// Set temporarily by the Rust backend when emitting a dependent module so that
62    /// `find_fn_def_by_name` can resolve same-module calls.
63    pub extra_fn_defs: Vec<FnDef>,
64    /// Functions that are part of a mutual-TCO SCC group (emitted as trampoline + wrappers).
65    /// Functions NOT in this set but with TailCalls are emitted as plain self-TCO loops.
66    pub mutual_tco_members: HashSet<String>,
67}
68
69/// Output files from a codegen backend.
70pub struct ProjectOutput {
71    /// Files to write: (relative_path, content).
72    pub files: Vec<(String, String)>,
73}
74
75/// Build a CodegenContext from parsed + type-checked items.
76pub fn build_context(
77    items: Vec<TopLevel>,
78    tc_result: &TypeCheckResult,
79    memo_fns: HashSet<String>,
80    project_name: String,
81    modules: Vec<ModuleInfo>,
82) -> CodegenContext {
83    let type_defs: Vec<TypeDef> = items
84        .iter()
85        .filter_map(|item| {
86            if let TopLevel::TypeDef(td) = item {
87                Some(td.clone())
88            } else {
89                None
90            }
91        })
92        .collect();
93
94    let fn_defs: Vec<FnDef> = items
95        .iter()
96        .filter_map(|item| {
97            if let TopLevel::FnDef(fd) = item {
98                Some(fd.clone())
99            } else {
100                None
101            }
102        })
103        .collect();
104
105    let module_prefixes: HashSet<String> = modules.iter().map(|m| m.prefix.clone()).collect();
106
107    // Compute which functions are in mutual-TCO SCC groups (emitted as trampoline + wrappers).
108    let mut mutual_tco_members = HashSet::new();
109    {
110        // Entry module (non-main)
111        let entry_fns: Vec<&FnDef> = fn_defs.iter().filter(|fd| fd.name != "main").collect();
112        for group in crate::call_graph::tailcall_scc_components(&entry_fns) {
113            for fd in &group {
114                mutual_tco_members.insert(fd.name.clone());
115            }
116        }
117        // Dependent modules
118        for module in &modules {
119            let mod_fns: Vec<&FnDef> = module.fn_defs.iter().collect();
120            for group in crate::call_graph::tailcall_scc_components(&mod_fns) {
121                for fd in &group {
122                    mutual_tco_members.insert(fd.name.clone());
123                }
124            }
125        }
126    }
127
128    CodegenContext {
129        items,
130        fn_sigs: tc_result.fn_sigs.clone(),
131        memo_fns,
132        memo_safe_types: tc_result.memo_safe_types.clone(),
133        type_defs,
134        fn_defs,
135        project_name,
136        modules,
137        module_prefixes,
138        policy: None,
139        emit_replay_runtime: false,
140        runtime_policy_from_env: false,
141        guest_entry: None,
142        emit_self_host_support: false,
143        extra_fn_defs: Vec::new(),
144        mutual_tco_members,
145    }
146}