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

323 lines
11 KiB
Rust

use prolog::ast::*;
use prolog::debray_allocator::*;
use prolog::codegen::*;
use prolog::machine::*;
use prolog::toplevel::*;
#[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);
}
}
}
}
pub(crate) trait TLInfo {
fn update_entry_index(&self, &ClauseName, usize, CodeIndex, &mut CodeIndex, usize);
// give the correct CodePtr offsets to CallClause's whose types are
// Named and Op. Enable late binding by setting to the default.
fn label_clauses(&self, code_size: usize, code_dir: &mut CodeDir, code: &mut Code)
{
for line in code.iter_mut() {
if let &mut Line::Control(ControlInstruction::CallClause(ref mut ct, a1, ..)) = line {
match ct {
&mut ClauseType::Named(ref n1, ref mut cp)
| &mut ClauseType::Op(ref n1, _, ref mut cp) => {
let entry = code_dir.entry((n1.clone(), a1)).or_insert(CodeIndex::default());
self.update_entry_index(n1, a1, entry.clone(), cp, code_size);
},
_ => {}
}
}
}
}
}
struct DeclInfo { name: ClauseName, arity: usize, module_name: ClauseName }
impl TLInfo for DeclInfo {
fn update_entry_index(&self, n1: &ClauseName, a1: usize, entry: CodeIndex,
cp: &mut CodeIndex, code_size: usize)
{
let (name, arity) = (self.name.clone(), self.arity);
{
let mut entry = entry.0.borrow_mut();
if entry.0 == IndexPtr::Undefined {
if &name == n1 && arity == a1 {
entry.0 = IndexPtr::Index(code_size);
}
}
entry.1 = self.module_name.clone();
}
*cp = entry;
}
}
struct QueryInfo {}
impl TLInfo for QueryInfo {
fn update_entry_index(&self, _: &ClauseName, _: usize, entry: CodeIndex,
cp: &mut CodeIndex, _: usize)
{
*cp = entry;
}
}
pub fn parse_code(wam: &mut Machine, buffer: &str) -> Result<TopLevelPacket, ParserError>
{
let atom_tbl = wam.atom_tbl();
let index = MachineCodeIndex {
code_dir: &mut wam.code_dir,
op_dir: &mut wam.op_dir
};
let mut worker = TopLevelWorker::new(buffer.as_bytes(), atom_tbl, index);
worker.parse_code()
}
// throw errors if declaration or query found.
fn compile_relation(tl: &TopLevel) -> Result<Code, ParserError>
{
let mut cg = CodeGenerator::<DebrayAllocator>::new();
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;
},
_ => {}
};
}
}
fn compile_appendix(code: &mut Code, queue: Vec<TopLevel>) -> Result<(), ParserError>
{
for tl in queue.iter() {
set_first_index(code);
code.append(&mut compile_relation(tl)?);
}
Ok(())
}
fn compile_query(terms: Vec<QueryTerm>, queue: Vec<TopLevel>, code_size: usize,
code_dir: &mut CodeDir)
-> Result<(Code, AllocVarDict), ParserError>
{
let mut cg = CodeGenerator::<DebrayAllocator>::new();
let mut code = try!(cg.compile_query(&terms));
compile_appendix(&mut code, queue)?;
let query_info = QueryInfo {};
query_info.label_clauses(code_size, code_dir, &mut code);
Ok((code, cg.take_vars()))
}
fn compile_decl(wam: &mut Machine, tl: TopLevel, queue: Vec<TopLevel>) -> EvalSession
{
match tl {
TopLevel::Declaration(Declaration::Op(op_decl)) => {
try_eval_session!(op_decl.submit(clause_name!("user"), &mut wam.op_dir));
EvalSession::EntrySuccess
},
TopLevel::Declaration(Declaration::UseModule(name)) =>
wam.use_module_in_toplevel(name),
TopLevel::Declaration(Declaration::UseQualifiedModule(name, exports)) =>
wam.use_qualified_module_in_toplevel(name, exports),
TopLevel::Declaration(_) =>
EvalSession::from(ParserError::InvalidModuleDecl),
_ => {
let name = try_eval_session!(if let Some(name) = tl.name() {
Ok(name)
} else {
Err(SessionError::NamelessEntry)
});
let mut code = try_eval_session!(compile_relation(&tl));
try_eval_session!(compile_appendix(&mut code, queue));
let decl_info = DeclInfo { name: name.clone(), arity: tl.arity(),
module_name: clause_name!("user") };
decl_info.label_clauses(wam.code_size(), &mut wam.code_dir, &mut code);
if !code.is_empty() {
wam.add_user_code(name, tl.arity(), code, tl.as_predicate().ok().unwrap())
} else {
EvalSession::from(SessionError::ImpermissibleEntry(String::from("no code generated.")))
}
}
}
}
pub fn compile_packet(wam: &mut Machine, tl: TopLevelPacket) -> EvalSession
{
match tl {
TopLevelPacket::Query(terms, queue) =>
match compile_query(terms, queue, wam.code_size(), &mut wam.code_dir) {
Ok((mut code, vars)) => wam.submit_query(code, vars),
Err(e) => EvalSession::from(e)
},
TopLevelPacket::Decl(tl, queue) =>
compile_decl(wam, tl, queue)
}
}
pub fn compile_listing(wam: &mut Machine, src_str: &str) -> EvalSession
{
fn get_module_name(module: &Option<Module>) -> ClauseName {
match module {
&Some(ref module) => module.module_decl.name.clone(),
_ => ClauseName::BuiltIn("user")
}
}
let mut module: Option<Module> = None;
let mut code_dir = CodeDir::new();
let mut op_dir = default_op_dir();
let mut code = Vec::new();
let tls = {
let indices = MachineCodeIndex { code_dir: &mut code_dir, op_dir: &mut op_dir };
let mut worker = TopLevelWorker::new(src_str.as_bytes(), wam.atom_tbl(), indices);
try_eval_session!(worker.parse_batch(&wam))
};
for tl in tls {
match tl {
TopLevelPacket::Query(..) =>
return EvalSession::from(ParserError::ExpectedRel),
TopLevelPacket::Decl(TopLevel::Declaration(Declaration::Module(module_decl)), _) =>
if module.is_none() {
module = Some(Module::new(module_decl));
} else {
return EvalSession::from(ParserError::InvalidModuleDecl);
},
TopLevelPacket::Decl(TopLevel::Declaration(Declaration::UseModule(name)), _) => {
if let Some(ref submodule) = wam.get_module(name.clone()) {
if let Some(ref mut module) = module {
let mut code_index = machine_code_index!(&mut code_dir, &mut op_dir);
module.use_module(submodule);
code_index.use_module(submodule);
continue;
}
} else {
return EvalSession::from(SessionError::ModuleNotFound);
}
wam.use_module_in_toplevel(name);
},
TopLevelPacket::Decl(TopLevel::Declaration(Declaration::UseQualifiedModule(name, exports)),
_)
=>
{
if let Some(ref submodule) = wam.get_module(name.clone()) {
if let Some(ref mut module) = module {
let mut code_index = machine_code_index!(&mut code_dir, &mut op_dir);
module.use_qualified_module(submodule, &exports);
code_index.use_qualified_module(submodule, &exports);
continue;
}
} else {
return EvalSession::from(SessionError::ModuleNotFound);
}
wam.use_qualified_module_in_toplevel(name, exports);
},
TopLevelPacket::Decl(TopLevel::Declaration(Declaration::Op(..)), _) => {},
TopLevelPacket::Decl(decl, queue) => {
let p = code.len() + wam.code_size();
let mut decl_code = try_eval_session!(compile_relation(&decl));
try_eval_session!(compile_appendix(&mut decl_code, queue));
let name = try_eval_session!(if let Some(name) = decl.name() {
Ok(name)
} else {
Err(SessionError::NamelessEntry)
});
let module_name = get_module_name(&module);
let decl_info = DeclInfo { name, arity: decl.arity(),
module_name: module_name.clone() };
{
let idx = code_dir.entry((decl_info.name.clone(), decl_info.arity))
.or_insert(CodeIndex::default());
set_code_index!(idx, IndexPtr::Index(p), module_name);
}
decl_info.label_clauses(p, &mut code_dir, &mut decl_code);
code.extend(decl_code.into_iter());
}
}
}
if let Some(mut module) = module {
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);
}
EvalSession::EntrySuccess
}