Files
scryer-prolog/src/prolog/compile.rs

376 lines
13 KiB
Rust

use prolog_parser::ast::*;
use prolog_parser::tabled_rc::TabledData;
use prolog::instructions::*;
use prolog::debray_allocator::*;
use prolog::codegen::*;
use prolog::machine::*;
use prolog::toplevel::*;
use std::collections::{HashMap, HashSet, VecDeque};
use std::io::Read;
use std::mem;
#[allow(dead_code)]
fn print_code(code: &Code) {
for clause in code {
match clause {
&Line::Arithmetic(ref arith) =>
println!("{}", arith),
&Line::Fact(ref fact) =>
for fact_instr in fact {
println!("{}", fact_instr);
},
&Line::Cut(ref cut) =>
println!("{}", cut),
&Line::Choice(ref choice) =>
println!("{}", choice),
&Line::Control(ref control) =>
println!("{}", control),
&Line::IndexedChoice(ref choice) =>
println!("{}", choice),
&Line::Indexing(ref indexing) =>
println!("{}", indexing),
&Line::Query(ref query) =>
for query_instr in query {
println!("{}", query_instr);
}
}
}
}
// throw errors if declaration or query found.
fn compile_relation(tl: &TopLevel, non_counted_bt: bool, flags: MachineFlags)
-> Result<Code, ParserError>
{
let mut cg = CodeGenerator::<DebrayAllocator>::new(non_counted_bt, flags);
match tl {
&TopLevel::Declaration(_) | &TopLevel::Query(_) =>
Err(ParserError::ExpectedRel),
&TopLevel::Predicate(ref clauses) =>
cg.compile_predicate(&clauses.0),
&TopLevel::Fact(ref fact) =>
Ok(cg.compile_fact(fact)),
&TopLevel::Rule(ref rule) =>
cg.compile_rule(rule)
}
}
// set first jmp_by_call or jmp_by_index instruction to code.len() -
// idx, where idx is the place it occurs. It only does this to the
// *first* uninitialized jmp index it encounters, then returns.
fn set_first_index(code: &mut Code)
{
let code_len = code.len();
for (idx, line) in code.iter_mut().enumerate() {
match line {
&mut Line::Control(ControlInstruction::JmpBy(_, ref mut offset, ..)) if *offset == 0 => {
*offset = code_len - idx;
break;
},
_ => {}
};
}
}
pub fn compile_appendix(code: &mut Code, queue: &VecDeque<TopLevel>, non_counted_bt: bool,
flags: MachineFlags)
-> Result<(), ParserError>
{
for tl in queue.iter() {
set_first_index(code);
code.append(&mut compile_relation(tl, non_counted_bt, flags)?);
}
Ok(())
}
fn compile_query(terms: Vec<QueryTerm>, queue: VecDeque<TopLevel>, flags: MachineFlags)
-> Result<(Code, AllocVarDict), ParserError>
{
// count backtracking inferences.
let mut cg = CodeGenerator::<DebrayAllocator>::new(false, flags);
let mut code = try!(cg.compile_query(&terms));
compile_appendix(&mut code, &queue, false, flags)?;
Ok((code, cg.take_vars()))
}
fn compile_decl(wam: &mut Machine, compiler: &mut ListingCompiler, decl: Declaration)
-> Result<IndexStore, SessionError>
{
let flags = wam.machine_flags();
let mut indices = default_index_store!(wam.indices.atom_tbl.clone());
let wam_indices = &mut wam.indices;
compiler.process_decl(decl, &mut wam.code_repo, wam_indices, &mut indices, flags)?;
Ok(indices)
}
pub fn compile_term(wam: &mut Machine, term: Term) -> EvalSession
{
let packet = try_eval_session!(consume_term(term, &mut wam.indices));
match packet {
TopLevelPacket::Query(terms, queue) =>
match compile_query(terms, queue, wam.machine_flags()) {
Ok((mut code, vars)) => wam.submit_query(code, vars),
Err(e) => EvalSession::from(e)
},
TopLevelPacket::Decl(TopLevel::Declaration(decl), _) => {
let mut compiler = ListingCompiler::new();
let indices = try_eval_session!(compile_decl(wam, &mut compiler, decl));
try_eval_session!(compiler.add_code(wam, vec![], indices));
EvalSession::EntrySuccess
},
_ => EvalSession::from(SessionError::UserPrompt)
}
}
struct GatherResult {
worker_results: Vec<(Predicate, VecDeque<TopLevel>)>,
toplevel_results: Vec<(Predicate, VecDeque<TopLevel>)>,
toplevel_indices: IndexStore
}
pub struct ListingCompiler {
non_counted_bt_preds: HashSet<PredicateKey>,
module: Option<Module>,
}
impl ListingCompiler {
#[inline]
pub fn new() -> Self {
ListingCompiler {
module: None, non_counted_bt_preds: HashSet::new()
}
}
fn use_module(&mut self, submodule: ClauseName, wam_indices: &mut IndexStore, indices: &mut IndexStore)
-> Result<(), SessionError>
{
let mod_name = self.get_module_name();
if let Some(submodule) = wam_indices.take_module(submodule) {
indices.use_module(&submodule)?;
if let &mut Some(ref mut module) = &mut self.module {
module.remove_module(mod_name, &submodule);
module.use_module(&submodule)?;
} else {
wam_indices.remove_module(clause_name!("user"), &submodule);
}
Ok(wam_indices.insert_module(submodule))
} else {
Err(SessionError::ModuleNotFound)
}
}
fn use_qualified_module(&mut self, submodule: ClauseName, exports: &Vec<PredicateKey>,
wam_indices: &mut IndexStore, indices: &mut IndexStore)
-> Result<(), SessionError>
{
let mod_name = self.get_module_name();
if let Some(submodule) = wam_indices.take_module(submodule) {
indices.use_qualified_module(&submodule, exports)?;
if let &mut Some(ref mut module) = &mut self.module {
module.remove_module(mod_name, &submodule);
module.use_qualified_module(&submodule, exports)?;
} else {
wam_indices.remove_module(clause_name!("user"), &submodule);
}
Ok(wam_indices.insert_module(submodule))
} else {
Err(SessionError::ModuleNotFound)
}
}
#[inline]
fn get_module_name(&self) -> ClauseName {
self.module.as_ref()
.map(|module| module.module_decl.name.clone())
.unwrap_or(ClauseName::BuiltIn("user"))
}
fn generate_code(&mut self, decls: Vec<(Predicate, VecDeque<TopLevel>)>,
wam: &Machine, code_dir: &mut CodeDir)
-> Result<Code, SessionError>
{
let mut code = vec![];
for (decl, queue) in decls {
let (name, arity) = decl.0.first().and_then(|cl| {
let arity = cl.arity();
cl.name().map(|name| (name, arity))
}).ok_or(SessionError::NamelessEntry)?;
let non_counted_bt = self.non_counted_bt_preds.contains(&(name.clone(), arity));
let p = code.len() + wam.code_size();
let mut decl_code = compile_relation(&TopLevel::Predicate(decl), non_counted_bt,
wam.machine_flags())?;
compile_appendix(&mut decl_code, &queue, non_counted_bt, wam.machine_flags())?;
let idx = code_dir.entry((name, arity)).or_insert(CodeIndex::default());
set_code_index!(idx, IndexPtr::Index(p), self.get_module_name());
code.extend(decl_code.into_iter());
}
Ok(code)
}
fn add_code(&mut self, wam: &mut Machine, code: Code, mut indices: IndexStore)
-> Result<(), SessionError>
{
let code_dir = mem::replace(&mut indices.code_dir, CodeDir::new());
let op_dir = mem::replace(&mut indices.op_dir, OpDir::new());
if let Some(mut module) = self.module.take() {
module.code_dir.extend(as_module_code_dir(code_dir));
module.op_dir.extend(op_dir.into_iter());
wam.add_module(module, code);
} else {
wam.add_batched_code(code, code_dir)?;
wam.add_batched_ops(op_dir);
}
Ok(())
}
fn add_non_counted_bt_flag(&mut self, name: ClauseName, arity: usize) {
self.non_counted_bt_preds.insert((name, arity));
}
fn process_decl(&mut self, decl: Declaration, code_repo: &mut CodeRepo,
wam_indices: &mut IndexStore, indices: &mut IndexStore,
flags: MachineFlags)
-> Result<(), SessionError>
{
match decl {
Declaration::Hook(hook, clause, queue) => {
let key = (hook.name(), hook.arity());
let preds = code_repo.term_dir.entry(key)
.or_insert((Predicate(vec![]), VecDeque::from(vec![])));
(preds.0).0.push(clause);
preds.1.extend(queue.into_iter());
let mut cg = CodeGenerator::<DebrayAllocator>::new(false, flags);
let mut code = cg.compile_predicate(&(preds.0).0)?;
compile_appendix(&mut code, &preds.1, false, flags)?;
match hook {
CompileTimeHook::TermExpansion =>
Ok(code_repo.term_expanders = code),
CompileTimeHook::GoalExpansion =>
Ok(code_repo.goal_expanders = code)
}
},
Declaration::NonCountedBacktracking(name, arity) =>
Ok(self.add_non_counted_bt_flag(name, arity)),
Declaration::Op(op_decl) =>
op_decl.submit(self.get_module_name(), &mut indices.op_dir),
Declaration::UseModule(name) =>
self.use_module(name, wam_indices, indices),
Declaration::UseQualifiedModule(name, exports) =>
self.use_qualified_module(name, &exports, wam_indices, indices),
Declaration::Module(module_decl) =>
if self.module.is_none() {
let module_name = module_decl.name.clone();
let atom_tbl = TabledData::new(module_name.to_rc());
Ok(self.module = Some(Module::new(module_decl, atom_tbl)))
} else {
Err(SessionError::from(ParserError::InvalidModuleDecl))
}
}
}
fn gather_items<R: Read>(&mut self, wam: &mut Machine, src: R, indices: &mut IndexStore)
-> Result<GatherResult, SessionError>
{
let flags = wam.machine_flags();
let machine_st = &mut wam.machine_st;
let wam_indices = &mut wam.indices;
let atom_tbl = wam_indices.atom_tbl.clone();
let mut worker = TopLevelBatchWorker::new(src, atom_tbl.clone(), flags,
wam_indices, &mut wam.policies,
&mut wam.code_repo);
let mut toplevel_results = vec![];
let mut toplevel_indices = default_index_store!(atom_tbl.clone());
while let Some(decl) = worker.consume(machine_st, indices)? {
if decl.is_module_decl() {
toplevel_indices.copy_and_swap(indices);
mem::swap(&mut worker.results, &mut toplevel_results);
worker.in_module = true;
self.process_decl(decl, worker.term_stream.code_repo,
worker.term_stream.indices,
indices, flags)?;
if let &Some(ref module) = &self.module {
worker.term_stream.set_atom_tbl(module.atom_tbl.clone());
}
} else {
self.process_decl(decl, worker.term_stream.code_repo,
worker.term_stream.indices,
indices, flags)?;
}
}
Ok(GatherResult {
worker_results: worker.results,
toplevel_results,
toplevel_indices
})
}
}
pub
fn compile_listing<R: Read>(wam: &mut Machine, src: R, mut indices: IndexStore) -> EvalSession
{
let mut compiler = ListingCompiler::new();
let mut results = try_eval_session!(compiler.gather_items(wam, src, &mut indices));
let module_code = try_eval_session!(compiler.generate_code(results.worker_results, wam,
&mut indices.code_dir));
let toplvl_code = try_eval_session!(compiler.generate_code(results.toplevel_results, wam,
&mut results.toplevel_indices.code_dir));
try_eval_session!(compiler.add_code(wam, module_code, indices));
try_eval_session!(compiler.add_code(wam, toplvl_code, results.toplevel_indices));
EvalSession::EntrySuccess
}
fn setup_indices(wam: &Machine, indices: &mut IndexStore) -> Result<(), SessionError> {
if let Some(ref builtins) = wam.indices.modules.get(&clause_name!("builtins")) {
indices.use_module(builtins)
} else {
Err(SessionError::ModuleNotFound)
}
}
pub fn compile_user_module<R: Read>(wam: &mut Machine, src: R) -> EvalSession {
let mut indices = default_index_store!(wam.indices.atom_tbl.clone());
try_eval_session!(setup_indices(&wam, &mut indices));
compile_listing(wam, src, indices)
}