leo_passes/
const_prop_unroll_and_morphing.rs

1// Copyright (C) 2019-2025 Provable Inc.
2// This file is part of the Leo library.
3
4// The Leo library is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// The Leo library is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
16
17use crate::{
18    CompilerState,
19    ConstPropagation,
20    Monomorphization,
21    Pass,
22    SymbolTableCreation,
23    TypeChecking,
24    TypeCheckingInput,
25    Unrolling,
26};
27
28use leo_ast::Node;
29use leo_errors::{CompilerError, Result};
30
31/// Pass that runs const propagation, loop unrolling, and monomorphization until a fixed point.
32pub struct ConstPropUnrollAndMorphing;
33
34impl Pass for ConstPropUnrollAndMorphing {
35    type Input = TypeCheckingInput;
36    type Output = ();
37
38    const NAME: &str = "ConstantPropogation+LoopUnrolling+Monomorphization";
39
40    fn do_pass(input: Self::Input, state: &mut CompilerState) -> Result<Self::Output> {
41        const LARGE_LOOP_BOUND: usize = 1024usize;
42
43        for _ in 0..LARGE_LOOP_BOUND {
44            let loop_unroll_output = Unrolling::do_pass((), state)?;
45
46            let const_prop_output = ConstPropagation::do_pass((), state)?;
47
48            let monomorphization_output = Monomorphization::do_pass((), state)?;
49
50            // Clear the symbol table and create it again. This is important because after all the passes above run, the
51            // program may have changed significantly (new functions may have been added, some functions may have been
52            // deleted, etc.) We do want to retain evaluated consts, so that const propagation can tell when it has evaluated a new one.
53            state.symbol_table.reset_but_consts();
54            SymbolTableCreation::do_pass((), state)?;
55
56            // Now run the type checker again to validate and infer types. Again, this is important because the program
57            // may have changed significantly after the passes above.
58            TypeChecking::do_pass(input.clone(), state)?;
59
60            if !const_prop_output.changed && !loop_unroll_output.loop_unrolled && !monomorphization_output.changed {
61                // We've got a fixed point, so see if we have any errors.
62                if let Some(not_evaluated_span) = const_prop_output.const_not_evaluated {
63                    return Err(CompilerError::const_not_evaluated(not_evaluated_span).into());
64                }
65
66                if let Some(not_evaluated_span) = const_prop_output.array_index_not_evaluated {
67                    return Err(CompilerError::array_index_not_evaluated(not_evaluated_span).into());
68                }
69
70                if let Some(not_evaluated_span) = const_prop_output.repeat_count_not_evaluated {
71                    return Err(CompilerError::repeat_count_not_evaluated(not_evaluated_span).into());
72                }
73
74                if let Some(not_evaluated_span) = const_prop_output.array_length_not_evaluated {
75                    return Err(CompilerError::array_length_not_evaluated(not_evaluated_span).into());
76                }
77
78                // Emit errors for all problematic calls
79                for call in &monomorphization_output.unresolved_calls {
80                    if let Some(arg) =
81                        call.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
82                    {
83                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
84                            "call to generic function",
85                            call.function.clone(),
86                            arg.span(),
87                        ));
88                    }
89                }
90
91                // Emit errors for all problematic struct expressions
92                for expr in &monomorphization_output.unresolved_struct_exprs {
93                    if let Some(arg) =
94                        expr.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
95                    {
96                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
97                            "struct expression",
98                            expr.path.clone(),
99                            arg.span(),
100                        ));
101                    }
102                }
103
104                // Emit errors for all problematic struct type instantiations
105                for ty in &monomorphization_output.unresolved_struct_types {
106                    if let Some(arg) =
107                        ty.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
108                    {
109                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
110                            "struct type",
111                            ty.path.clone(),
112                            arg.span(),
113                        ));
114                    }
115                }
116
117                // Exit with the handler's last error.
118                state.handler.last_err()?;
119
120                if let Some(not_unrolled_span) = loop_unroll_output.loop_not_unrolled {
121                    return Err(CompilerError::loop_bounds_not_evaluated(not_unrolled_span).into());
122                }
123
124                return Ok(());
125            }
126        }
127
128        // Note that it's challenging to write code in practice that demonstrates this error, because Leo code
129        // with many nested loops or operations will blow the stack in the compiler before this bound is hit.
130        Err(CompilerError::const_prop_unroll_many_loops(LARGE_LOOP_BOUND, Default::default()).into())
131    }
132}
leo_passes/const_prop_unroll_and_morphing.rs

leo_passes/
const_prop_unroll_and_morphing.rs
