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restore [o|i]ip zeroing to trust and fix '$get_clause_p'/3 (#2238)

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This commit is contained in:
Mark
2023-12-20 20:45:11 -07:00
parent 44a61fa72c
commit 46e432c4d9
5 changed files with 86 additions and 75 deletions
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5
src/lib/builtins.pl
View File

@@ -1239,7 +1239,10 @@ call_retract_helper(Head, Body, P, Module) :-
; ClauseQualifier = Module
),
ClauseQualifier:'$clause'(Head, Body),
'$get_clause_p'(Head, P, Module).
% ensure '$get_clause_p'/3 is not the last clause so it can
% recover the choice point of '$clause' if necessary.
'$get_clause_p'(Head, P, Module),
true.
call_retract(Head, Body, Name, Arity, Module) :-
findall(P, builtins:call_retract_helper(Head, Body, P, Module), Ps),

23
src/machine/mod.rs
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@@ -1010,6 +1010,20 @@ impl Machine {
self.machine_st.heap.truncate(target_h);
// these registers don't need to be reset here and MUST
// NOT be (nor in indexed_try! trust_epilogue is an
// exception, see next paragraph)! oip could be reset
// without any adverse effects but iip is needed by
// get_clause_p to find the last executed clause/2 clause.
// trust_epilogue must reset these for the sake of
// subsequent predicates beginning with
// switch_to_term. get_clause_p copes by checking
// self.machine_st.b > self.machine.e: if true, it is safe
// to use self.machine_st.iip; if false, use the choice
// point left at the top of the stack by '$clause'
// (specifically its biip value).
// self.machine_st.oip = 0;
// self.machine_st.iip = 0;
} else {
@@ -1059,13 +1073,8 @@ impl Machine {
self.machine_st.stack.truncate(b);
self.machine_st.heap.truncate(target_h);
// these registers don't need to be reset here and MUST NOT be
// (nor in indexed_try to trust_epilogue)! oip could be reset
// without any adverse effects but iip is needed by
// get_clause_p to find the last executed clause/2 clause.
// self.machine_st.oip = 0;
// self.machine_st.iip = 0;
self.machine_st.oip = 0;
self.machine_st.iip = 0;
}
#[inline(always)]

31
src/machine/preprocessor.rs
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@@ -565,21 +565,6 @@ impl Preprocessor {
}
}
/*
fn try_term_to_query<'a, LS: LoadState<'a>>(
&mut self,
loader: &mut Loader<'a, LS>,
terms: Vec<Term>,
cut_context: CutContext,
) -> Result<TopLevel, CompilationError> {
Ok(TopLevel::Query(self.setup_query(
loader,
terms,
cut_context,
)?))
}
*/
pub(super) fn try_term_to_tl<'a, LS: LoadState<'a>>(
&mut self,
loader: &mut Loader<'a, LS>,
@@ -607,20 +592,4 @@ impl Preprocessor {
}
}
}
/*
fn try_terms_to_tls<'a, I: IntoIterator<Item = Term>, LS: LoadState<'a>>(
&mut self,
loader: &mut Loader<'a, LS>,
terms: I,
) -> Result<VecDeque<TopLevel>, CompilationError> {
let mut results = VecDeque::new();
for term in terms.into_iter() {
results.push_back(self.try_term_to_tl(loader, term)?);
}
Ok(results)
}
*/
}

6
src/machine/stack.rs
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@@ -203,6 +203,12 @@ impl Stack {
}
}
pub(crate) fn top(&self) -> usize {
unsafe {
(*self.buf.ptr.get()) as usize - self.buf.base as usize
}
}
pub(crate) fn allocate_or_frame(&mut self, num_cells: usize) -> usize {
let frame_size = OrFrame::size_of(num_cells);

96
src/machine/system_calls.rs
View File

@@ -1176,14 +1176,12 @@ impl Machine {
CompilationTarget::Module(target) => target,
};
let bp = self
let mut bp = self
.indices
.get_predicate_code_index(atom!("$clause"), 2, module_name)
.and_then(|idx| idx.local())
.unwrap();
let p = self.machine_st.iip as usize;
macro_rules! extract_ptr {
($ptr: expr) => {
match $ptr {
@@ -1199,45 +1197,71 @@ impl Machine {
};
}
match &self.code[bp] {
Instruction::IndexingCode(ref indexing_code) => {
let indexing_code_ptr = match &indexing_code[0] {
&IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, _, s)) => {
if key.1 > 0 {
s
} else {
c
loop {
match &self.code[bp] {
Instruction::IndexingCode(ref indexing_code) => {
let indexing_code_ptr = match &indexing_code[0] {
&IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, _, s)) => {
if key.1 > 0 {
s
} else {
c
}
}
}
_ => {
unreachable!()
}
};
_ => {
unreachable!()
}
};
let boip = extract_ptr!(indexing_code_ptr);
let boip = extract_ptr!(indexing_code_ptr);
let boip = match &indexing_code[boip] {
IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref hm)) => {
boip + extract_ptr!(hm.get(&key).cloned().unwrap())
}
IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref hm)) => {
boip + extract_ptr!(hm.get(&Literal::Atom(key.0)).cloned().unwrap())
}
_ => boip,
};
let boip = match &indexing_code[boip] {
IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref hm)) => {
boip + extract_ptr!(hm.get(&key).cloned().unwrap())
}
IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref hm)) => {
boip + extract_ptr!(hm.get(&Literal::Atom(key.0)).cloned().unwrap())
}
_ => boip,
};
match &indexing_code[boip] {
IndexingLine::IndexedChoice(indexed_choice) => {
return (
skeleton.core.clause_clause_locs[p],
bp + indexed_choice[p].offset(),
);
match &indexing_code[boip] {
IndexingLine::IndexedChoice(indexed_choice) => {
let p = if self.machine_st.b > self.machine_st.e {
// this means the last
// self.machine_st.iip value has yet
// to be overwritten by the Trust
// instruction. In this case, return
// it.
self.machine_st.iip as usize
} else {
// otherwise, read the '$clause'
// choicepoint from the top of the
// stack. this is very volatile in
// that it depends on '$clause'
// immediately preceding
// '$get_clause_p', which cannot be
// the last clause of the retract
// helper to delay deallocation of its
// environment frame.
let clause_b = self.machine_st.stack.top();
self.machine_st.stack.index_or_frame(clause_b).prelude.biip as usize
};
return (
skeleton.core.clause_clause_locs[p],
bp + indexed_choice[p].offset(),
);
}
_ => unreachable!(),
}
_ => unreachable!(),
}
}
_ => {
return (skeleton.core.clause_clause_locs[p], bp);
&Instruction::RevJmpBy(offset) => {
bp -= offset;
}
_ => {
return (skeleton.core.clause_clause_locs.back().cloned().unwrap(), bp);
}
}
}
}