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// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
#![allow(
clippy::indexing_slicing,
clippy::as_conversions,
clippy::pattern_type_mismatch
)]
use super::{Compiler, CompilerError, ComprehensionType, ContextType, Result};
use crate::ast::{self, LiteralStmt, Query};
use crate::rvm::instructions::GuardMode;
use crate::rvm::program::RuleType;
use crate::rvm::Instruction;
use alloc::format;
use alloc::vec::Vec;
impl<'a> Compiler<'a> {
pub(super) fn compile_query(&mut self, query: &Query) -> Result<()> {
self.push_scope();
let result = {
let schedule = match &self.policy.inner.schedule {
Some(s) => s
.queries
.get_checked(self.current_module_index, query.qidx)
.map_err(|err| {
CompilerError::General {
message: format!("schedule out of bounds: {err}"),
}
.at(&query.span)
})?,
None => None,
};
let ordered_stmts: Vec<&LiteralStmt> = match schedule {
Some(schedule) => schedule
.order
.iter()
.map(|i| &query.stmts[*i as usize])
.collect(),
None => query.stmts.iter().collect(),
};
self.hoist_loops_and_compile_statements(&ordered_stmts)
};
self.pop_scope();
result
}
pub(super) fn hoist_loops_and_compile_statements(
&mut self,
stmts: &[&LiteralStmt],
) -> Result<()> {
for (idx, stmt) in stmts.iter().enumerate() {
if !stmt.with_mods.is_empty() {
return Err(CompilerError::WithKeywordUnsupported.at(&stmt.span));
}
let loop_exprs = self.get_statement_loops(stmt)?;
if !loop_exprs.is_empty() {
return self.compile_hoisted_loops(&stmts[idx..], &loop_exprs);
}
if matches!(&stmt.literal, ast::Literal::SomeIn { .. }) {
if let ast::Literal::SomeIn {
ref key,
ref value,
ref collection,
..
} = &stmt.literal
{
let some_result_reg = self.compile_some_in_loop_with_remaining_statements(
key,
value,
collection,
&stmts[idx..],
)?;
// Inside an `every` body a `some ... in` acts as a condition
// on the current iteration: if it matches nothing the
// iteration must fail. Unlike a top-level rule body (where
// per-iteration context yields produce the results), the
// `every` body has no yield, so the loop result register is
// otherwise discarded. Guard on it so a `some` that matches
// nothing fails the enclosing `every` iteration.
if matches!(
self.context_stack.last().map(|c| &c.context_type),
Some(ContextType::Every)
) {
self.emit_instruction(
Instruction::Guard {
register: some_result_reg,
mode: GuardMode::Condition,
},
&stmt.span,
);
}
return Ok(());
}
}
self.compile_single_statement(stmt)?;
}
self.hoist_loops_and_emit_context_yield()
}
pub(super) fn hoist_loops_and_emit_context_yield(&mut self) -> Result<()> {
if let Some(context) = self.context_stack.last() {
match &context.context_type {
ContextType::Every => {
return Ok(());
}
ContextType::Rule(_) | ContextType::Comprehension(_) => {}
}
}
let (key_expr, value_expr) = match self.context_stack.last_mut() {
Some(context) => {
if context.key_value_loops_hoisted {
return self.emit_context_yield();
}
(context.key_expr.clone(), context.value_expr.clone())
}
None => return Ok(()),
};
let mut key_value_loops = Vec::new();
if let Some(expr) = key_expr.as_ref() {
key_value_loops.extend(self.get_expr_loops(expr)?);
}
if let Some(expr) = value_expr.as_ref() {
key_value_loops.extend(self.get_expr_loops(expr)?);
}
if !key_value_loops.is_empty() {
if let Some(context) = self.context_stack.last_mut() {
context.key_value_loops_hoisted = true;
}
self.compile_hoisted_loops(&[], &key_value_loops)
} else {
self.emit_context_yield()
}
}
pub(super) fn emit_context_yield(&mut self) -> Result<()> {
if let Some(context) = self.context_stack.last().cloned() {
let dest_register = context.dest_register;
let span = &context.span;
let value_register = match context.value_expr {
Some(expr) => self.compile_rego_expr(&expr)?,
None => {
let value_reg = self.alloc_register()?;
self.emit_instruction(
Instruction::LoadBool {
dest: value_reg,
value: true,
},
span,
);
value_reg
}
};
let key_register = context
.key_expr
.map(|key_expr| self.compile_rego_expr(&key_expr))
.unwrap_or(Ok(value_register))?;
match context.context_type {
ContextType::Comprehension(ComprehensionType::Array) => {
self.emit_instruction(
Instruction::ComprehensionYield {
value_reg: value_register,
key_reg: None,
},
span,
);
}
ContextType::Comprehension(ComprehensionType::Set) => {
self.emit_instruction(
Instruction::ComprehensionYield {
value_reg: value_register,
key_reg: None,
},
span,
);
}
ContextType::Rule(RuleType::PartialSet) => {
self.emit_instruction(
Instruction::SetAdd {
set: dest_register,
value: value_register,
},
span,
);
}
ContextType::Comprehension(ComprehensionType::Object) => {
self.emit_instruction(
Instruction::ComprehensionYield {
value_reg: value_register,
key_reg: Some(key_register),
},
span,
);
}
ContextType::Rule(RuleType::PartialObject) => {
self.emit_instruction(
Instruction::ObjectSet {
obj: dest_register,
key: key_register,
value: value_register,
},
span,
);
}
ContextType::Rule(RuleType::Complete) => {
self.emit_instruction(
Instruction::Move {
dest: dest_register,
src: value_register,
},
span,
);
}
ContextType::Every => {}
}
Ok(())
} else {
Err(CompilerError::MissingYieldContext.into())
}
}
pub(super) fn compile_single_statement(&mut self, stmt: &LiteralStmt) -> Result<()> {
match &stmt.literal {
ast::Literal::Expr { expr, .. } => {
let assert_condition = !matches!(expr.as_ref(), ast::Expr::AssignExpr { .. });
let _condition_reg =
self.compile_rego_expr_with_span(expr, &stmt.span, assert_condition)?;
}
ast::Literal::SomeIn { .. } => {
return Err(CompilerError::SomeInNotHoisted.at(&stmt.span));
}
ast::Literal::Every {
key,
value,
domain,
query,
..
} => {
self.compile_every_quantifier(key, value, domain, query, &stmt.span)?;
}
ast::Literal::SomeVars { vars, .. } => {
for var in vars {
self.add_unbound_variable(var.text());
}
}
ast::Literal::NotExpr { expr, .. } => {
let expr_reg = self.with_soft_assert_mode(true, |compiler| {
compiler.compile_rego_expr_with_span(expr, expr.span(), false)
})?;
let negated_reg = self.alloc_register()?;
self.emit_instruction(
Instruction::Not {
dest: negated_reg,
operand: expr_reg,
},
&stmt.span,
);
self.emit_instruction(
Instruction::Guard {
register: negated_reg,
mode: GuardMode::Condition,
},
&stmt.span,
);
}
}
Ok(())
}
}