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 globally evaluated consts, so that const propagation can tell when
53            // it has evaluated a new one.
54            state.symbol_table.reset_but_consts();
55            SymbolTableCreation::do_pass((), state)?;
56
57            // Now run the type checker again to validate and infer types. Again, this is important because the program
58            // may have changed significantly after the passes above.
59            TypeChecking::do_pass(input.clone(), state)?;
60
61            if !const_prop_output.changed && !loop_unroll_output.loop_unrolled && !monomorphization_output.changed {
62                // We've got a fixed point, so see if we have any errors.
63                if let Some(not_evaluated_span) = const_prop_output.const_not_evaluated {
64                    return Err(CompilerError::const_not_evaluated(not_evaluated_span).into());
65                }
66
67                if let Some(not_evaluated_span) = const_prop_output.array_index_not_evaluated {
68                    return Err(CompilerError::array_index_not_evaluated(not_evaluated_span).into());
69                }
70
71                if let Some(not_evaluated_span) = const_prop_output.repeat_count_not_evaluated {
72                    return Err(CompilerError::repeat_count_not_evaluated(not_evaluated_span).into());
73                }
74
75                if let Some(not_evaluated_span) = const_prop_output.array_length_not_evaluated {
76                    return Err(CompilerError::array_length_not_evaluated(not_evaluated_span).into());
77                }
78
79                // Emit errors for all problematic calls
80                for call in &monomorphization_output.unresolved_calls {
81                    if let Some(arg) =
82                        call.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
83                    {
84                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
85                            "call to generic function",
86                            call.function.clone(),
87                            arg.span(),
88                        ));
89                    }
90                }
91
92                // Emit errors for all problematic struct expressions
93                for expr in &monomorphization_output.unresolved_struct_exprs {
94                    if let Some(arg) =
95                        expr.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
96                    {
97                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
98                            "struct expression",
99                            expr.path.clone(),
100                            arg.span(),
101                        ));
102                    }
103                }
104
105                // Emit errors for all problematic struct type instantiations
106                for ty in &monomorphization_output.unresolved_struct_types {
107                    if let Some(arg) =
108                        ty.const_arguments.iter().find(|arg| !matches!(arg, leo_ast::Expression::Literal(_)))
109                    {
110                        state.handler.emit_err(CompilerError::const_generic_not_resolved(
111                            "struct type",
112                            ty.path.clone(),
113                            arg.span(),
114                        ));
115                    }
116                }
117
118                // Exit with the handler's last error.
119                state.handler.last_err()?;
120
121                if let Some(not_unrolled_span) = loop_unroll_output.loop_not_unrolled {
122                    return Err(CompilerError::loop_bounds_not_evaluated(not_unrolled_span).into());
123                }
124
125                return Ok(());
126            }
127        }
128
129        // Note that it's challenging to write code in practice that demonstrates this error, because Leo code
130        // with many nested loops or operations will blow the stack in the compiler before this bound is hit.
131        Err(CompilerError::const_prop_unroll_many_loops(LARGE_LOOP_BOUND, Default::default()).into())
132    }
133}
leo_passes/const_prop_unroll_and_morphing.rs

leo_passes/
const_prop_unroll_and_morphing.rs
