| 1 | //! Call resolution pass. |
| 2 | //! |
| 3 | //! Rewrites `Call(FuncRef::External(name), args)` to |
| 4 | //! `Call(FuncRef::Internal(idx), args)` when `name` matches a |
| 5 | //! function defined in the same module. This enables the inliner |
| 6 | //! to find the callee's IR body. |
| 7 | //! |
| 8 | //! Runs as the first pass at O1+ (before Mem2Reg). |
| 9 | |
| 10 | use super::pass::Pass; |
| 11 | use crate::ir::inst::*; |
| 12 | use std::collections::HashMap; |
| 13 | |
| 14 | pub struct CallResolve; |
| 15 | |
| 16 | impl Pass for CallResolve { |
| 17 | fn name(&self) -> &'static str { |
| 18 | "call-resolve" |
| 19 | } |
| 20 | |
| 21 | fn run(&self, module: &mut Module) -> bool { |
| 22 | // Build name → index mapping for all functions in the module. |
| 23 | let name_to_idx: HashMap<String, u32> = module |
| 24 | .functions |
| 25 | .iter() |
| 26 | .enumerate() |
| 27 | .map(|(i, f)| (f.name.clone(), i as u32)) |
| 28 | .collect(); |
| 29 | |
| 30 | let mut changed = false; |
| 31 | |
| 32 | for func in &mut module.functions { |
| 33 | for block in &mut func.blocks { |
| 34 | for inst in &mut block.insts { |
| 35 | if let InstKind::Call(ref mut func_ref, _) = &mut inst.kind { |
| 36 | if let FuncRef::External(name) = func_ref { |
| 37 | if let Some(&idx) = name_to_idx.get(name.as_str()) { |
| 38 | *func_ref = FuncRef::Internal(idx); |
| 39 | changed = true; |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | changed |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | #[cfg(test)] |
| 52 | mod tests { |
| 53 | use super::*; |
| 54 | use crate::ir::inst::*; |
| 55 | use crate::ir::types::{IntWidth, IrType}; |
| 56 | use crate::opt::pass::Pass; |
| 57 | |
| 58 | #[test] |
| 59 | fn resolves_internal_calls() { |
| 60 | let mut m = Module::new("test".into()); |
| 61 | |
| 62 | // Callee: function "double_it" |
| 63 | let mut callee = Function::new("double_it".into(), vec![], IrType::Int(IntWidth::I32)); |
| 64 | callee.block_mut(callee.entry).terminator = Some(Terminator::Return(None)); |
| 65 | m.add_function(callee); |
| 66 | |
| 67 | // Caller: calls "double_it" via External ref |
| 68 | let mut caller = Function::new("main".into(), vec![], IrType::Void); |
| 69 | let call_id = caller.next_value_id(); |
| 70 | caller.register_type(call_id, IrType::Int(IntWidth::I32)); |
| 71 | caller.block_mut(caller.entry).insts.push(Inst { |
| 72 | id: call_id, |
| 73 | ty: IrType::Int(IntWidth::I32), |
| 74 | span: crate::lexer::Span { |
| 75 | file_id: 0, |
| 76 | start: crate::lexer::Position { line: 0, col: 0 }, |
| 77 | end: crate::lexer::Position { line: 0, col: 0 }, |
| 78 | }, |
| 79 | kind: InstKind::Call(FuncRef::External("double_it".into()), vec![]), |
| 80 | }); |
| 81 | caller.block_mut(caller.entry).terminator = Some(Terminator::Return(None)); |
| 82 | m.add_function(caller); |
| 83 | |
| 84 | let pass = CallResolve; |
| 85 | let changed = pass.run(&mut m); |
| 86 | assert!(changed, "should resolve the internal call"); |
| 87 | |
| 88 | // Verify the call was rewritten. |
| 89 | let caller_func = &m.functions[1]; |
| 90 | let call_inst = &caller_func.blocks[0].insts[0]; |
| 91 | match &call_inst.kind { |
| 92 | InstKind::Call(FuncRef::Internal(idx), _) => { |
| 93 | assert_eq!(*idx, 0, "should point to function index 0 (double_it)"); |
| 94 | } |
| 95 | other => panic!("expected Internal call, got {:?}", other), |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | #[test] |
| 100 | fn leaves_external_calls_unchanged() { |
| 101 | let mut m = Module::new("test".into()); |
| 102 | let mut f = Function::new("main".into(), vec![], IrType::Void); |
| 103 | let call_id = f.next_value_id(); |
| 104 | f.register_type(call_id, IrType::Void); |
| 105 | f.block_mut(f.entry).insts.push(Inst { |
| 106 | id: call_id, |
| 107 | ty: IrType::Void, |
| 108 | span: crate::lexer::Span { |
| 109 | file_id: 0, |
| 110 | start: crate::lexer::Position { line: 0, col: 0 }, |
| 111 | end: crate::lexer::Position { line: 0, col: 0 }, |
| 112 | }, |
| 113 | kind: InstKind::Call(FuncRef::External("afs_write_int".into()), vec![]), |
| 114 | }); |
| 115 | f.block_mut(f.entry).terminator = Some(Terminator::Return(None)); |
| 116 | m.add_function(f); |
| 117 | |
| 118 | let pass = CallResolve; |
| 119 | let changed = pass.run(&mut m); |
| 120 | assert!(!changed, "runtime calls should stay External"); |
| 121 | } |
| 122 | } |
| 123 |