forked from rust-lang/rust
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request rust-lang#21 from Chris-Hawblitzel/debugger
Add preliminary support for AIR-level model reconstruction
- Loading branch information
Showing
21 changed files
with
477 additions
and
237 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,109 @@ | ||
| //! Provides an AIR-level interface to the model returned by the SMT solver | ||
| //! when it reaches a SAT conclusion | ||
|
|
||
| use crate::ast::{Decl, DeclX, Ident, Snapshots}; | ||
| use crate::context::Context; | ||
| use crate::smt_util::new_const; | ||
| use std::collections::HashMap; | ||
| use std::fmt; | ||
| use z3::ast::Dynamic; | ||
|
|
||
| #[derive(Debug)] | ||
| /// AIR-level model of a concrete counterexample | ||
| pub struct Model<'a> { | ||
| /// Handle to the original Z3 model; only for internal use, e.g., for `eval` | ||
| z3_model: z3::Model<'a>, | ||
| /// Internal mapping of snapshot IDs to snapshots that map AIR variables to usage counts. | ||
| /// Generated when converting mutable variables to Z3-level constants. | ||
| id_snapshots: Snapshots, | ||
| /// Externally facing mapping from snapshot IDs to snapshots that map AIR variables | ||
| /// to their concrete values. | ||
| /// TODO: Upgrade to a semantics-preserving value type, instead of String. | ||
| value_snapshots: HashMap<Ident, HashMap<Ident, String>>, | ||
| } | ||
|
|
||
| impl<'a> Model<'a> { | ||
| /// Returns an (unpopulated) AIR model object. Must call [build()] to fully populate. | ||
| /// # Arguments | ||
| /// * `model` - The model that Z3 returns | ||
| /// * `snapshots` - Internal mapping of snapshot IDs to snapshots that map AIR variables to usage counts. | ||
| pub fn new(model: z3::Model<'a>, snapshots: Snapshots) -> Model<'a> { | ||
| // println!("Creating a new model with {} snapshots", snapshots.len()); | ||
| Model { z3_model: model, id_snapshots: snapshots, value_snapshots: HashMap::new() } | ||
| } | ||
|
|
||
| /// Convert a Z3 AST variable `var_stmt` into a String value | ||
| /// Uses `var_name` only for error reporting. | ||
| fn lookup_z3_var(&self, var_name: &String, var_smt: &Dynamic) -> String { | ||
| if let Some(x) = self.z3_model.eval(var_smt) { | ||
| if let Some(b) = x.as_bool() { | ||
| format!("{}", b) | ||
| } else if let Some(i) = x.as_int() { | ||
| format!("{}", i) | ||
| } else { | ||
| println!("Unexpected type returned from model eval for {}", var_name); | ||
| "".to_string() | ||
| } | ||
| } else { | ||
| println!("Failed to extract evaluation of var {} from Z3's model", var_name); | ||
| "".to_string() | ||
| } | ||
| } | ||
|
|
||
| /// Populate the AIR-level model based on the Z3 model | ||
| /// `local_vars` should be a list of [DeclX::Const] values | ||
| /// representing the function's local non-mutable variables | ||
| /// (e.g., function parameters) | ||
| /// This is decoupled from the Model's constructor so that | ||
| /// we only do this expensive work when called in debug mode. | ||
| pub fn build(&mut self, context: &mut Context, local_vars: Vec<Decl>) { | ||
| println!("Building the AIR model"); | ||
| for (snap_id, id_snapshot) in &self.id_snapshots { | ||
| let mut value_snapshot = HashMap::new(); | ||
| println!("Snapshot {} has {} variables", snap_id, id_snapshot.len()); | ||
| for (var_id, var_count) in &*id_snapshot { | ||
| let var_name = crate::var_to_const::rename_var(&*var_id, *var_count); | ||
| println!("\t{}", var_name); | ||
| let var_smt = context | ||
| .vars | ||
| .get(&var_name) | ||
| .unwrap_or_else(|| panic!("internal error: variable {} not found", var_name)); | ||
| let val = self.lookup_z3_var(&var_name, var_smt); | ||
| value_snapshot.insert(var_id.clone(), val); | ||
| } | ||
| // Add the local variables to every snapshot for uniformity | ||
| println!("local_vars has {} variables", local_vars.len()); | ||
| for decl in local_vars.iter() { | ||
| if let DeclX::Const(var_name, typ) = &**decl { | ||
| println!("\t{}", var_name); | ||
| let var_smt = new_const(context, &var_name, &typ); | ||
| let val = self.lookup_z3_var(&var_name, &var_smt); | ||
| value_snapshot.insert(var_name.clone(), val); | ||
| //value_snapshot.insert(Rc::new((*var_name).clone()), val); | ||
| } else { | ||
| panic!("Expected local vars to all be constants at this point"); | ||
| } | ||
| } | ||
| self.value_snapshots.insert(snap_id.clone(), value_snapshot); | ||
| } | ||
| } | ||
|
|
||
| /// Look up the value of an AIR variable `name` in a given `snapshot` | ||
| pub fn query_variable(&self, snapshot: Ident, name: Ident) -> Option<String> { | ||
| Some(self.value_snapshots.get(&snapshot)?.get(&name)?.to_string()) | ||
| } | ||
| } | ||
|
|
||
| impl<'a> fmt::Display for Model<'a> { | ||
| /// Dump the contents of the AIR model for debugging purposes | ||
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | ||
| write!(f, "\nDisplaying model with {} snapshots\n", self.value_snapshots.len())?; | ||
| for (snap_id, value_snapshot) in &self.value_snapshots { | ||
| write!(f, "Snapshot <{}>:\n", snap_id)?; | ||
| for (var_name, value) in &*value_snapshot { | ||
| write!(f, "\t{} -> {}\n", var_name, value)?; | ||
| } | ||
| } | ||
| Ok(()) | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,19 @@ | ||
| use crate::ast::{Typ, TypX}; | ||
| use crate::context::Context; | ||
| use z3::ast::{Bool, Dynamic, Int}; | ||
|
|
||
| pub(crate) fn new_const<'ctx>( | ||
| context: &mut Context<'ctx>, | ||
| name: &String, | ||
| typ: &Typ, | ||
| ) -> Dynamic<'ctx> { | ||
| match &**typ { | ||
| TypX::Bool => Bool::new_const(context.context, name.clone()).into(), | ||
| TypX::Int => Int::new_const(context.context, name.clone()).into(), | ||
| TypX::Named(x) => { | ||
| let sort = &context.typs[x]; | ||
| let fdecl = z3::FuncDecl::new(context.context, name.clone(), &[], sort); | ||
| fdecl.apply(&[]) | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.