[core] codegen/expr: Implement comparison of tuples

nac3core/src/codegen/expr.rs

@@ -40,6 +40,7 @@ use nac3parser::ast::{
     self, Boolop, Cmpop, Comprehension, Constant, Expr, ExprKind, Location, Operator, StrRef,
     Unaryop,
 };
+use std::cmp::min;
 use std::iter::{repeat, repeat_with};
 use std::{collections::HashMap, convert::TryInto, iter::once, iter::zip};
 
@@ -2303,6 +2304,119 @@ pub fn gen_cmpop_expr_with_values<'ctx, G: CodeGenerator>(
                 };
 
                 gen_list_cmpop(generator, ctx)?
+            } else if [left_ty, right_ty].iter().any(|ty| matches!(&*ctx.unifier.get_ty_immutable(*ty), TypeEnum::TTuple { .. })) {
+                let TypeEnum::TTuple { ty: left_tys, .. } = &*ctx.unifier.get_ty_immutable(left_ty) else {
+                    return Err(format!("'{}' not supported between instances of '{}' and '{}'", op.op_info().symbol, ctx.unifier.stringify(left_ty), ctx.unifier.stringify(right_ty)))
+                };
+                let TypeEnum::TTuple { ty: right_tys, .. } = &*ctx.unifier.get_ty_immutable(right_ty) else {
+                    return Err(format!("'{}' not supported between instances of '{}' and '{}'", op.op_info().symbol, ctx.unifier.stringify(left_ty), ctx.unifier.stringify(right_ty)))
+                };
+
+                if ![Cmpop::Eq, Cmpop::NotEq].contains(op) {
+                    todo!("Only __eq__ and __ne__ is implemented for tuples")
+                }
+
+                let llvm_i1 = ctx.ctx.bool_type();
+                let llvm_i32 = ctx.ctx.i32_type();
+
+                // Assume `true` by default
+                let cmp_addr = generator.gen_var_alloc(ctx, llvm_i1.into(), None).unwrap();
+                ctx.builder.build_store(cmp_addr, llvm_i1.const_all_ones()).unwrap();
+
+                let current_bb = ctx.builder.get_insert_block().unwrap();
+                let post_foreach_cmp = ctx.ctx.insert_basic_block_after(current_bb, "foreach.cmp.end");
+
+                ctx.builder.position_at_end(post_foreach_cmp);
+                let cmp_phi = ctx.builder.build_phi(llvm_i1, "").unwrap();
+                ctx.builder.position_at_end(current_bb);
+
+                // Generate comparison between each element
+                let min_len = min(left_tys.len(), right_tys.len());
+                for i in 0..min_len {
+                    let current_bb = ctx.builder.get_insert_block().unwrap();
+                    let bb = ctx.ctx.insert_basic_block_after(current_bb, &format!("foreach.cmp.tuple.{i}e"));
+                    ctx.builder.build_unconditional_branch(bb).unwrap();
+
+                    ctx.builder.position_at_end(bb);
+                    let left_ty = left_tys[i];
+                    let left_elem = {
+                        let plhs = generator.gen_var_alloc(ctx, lhs.get_type(), None).unwrap();
+                        ctx.builder.build_store(plhs, *lhs).unwrap();
+
+                        ctx.build_in_bounds_gep_and_load(
+                            plhs,
+                            &[llvm_i32.const_zero(), llvm_i32.const_int(i as u64, false)],
+                            None,
+                        )
+                    };
+                    let right_ty = right_tys[i];
+                    let right_elem = {
+                        let prhs = generator.gen_var_alloc(ctx, rhs.get_type(), None).unwrap();
+                        ctx.builder.build_store(prhs, *rhs).unwrap();
+
+                        ctx.build_in_bounds_gep_and_load(
+                            prhs,
+                            &[llvm_i32.const_zero(), llvm_i32.const_int(i as u64, false)],
+                            None,
+                        )
+                    };
+
+                    gen_if_callback(
+                        generator,
+                        ctx,
+                        |generator, ctx| {
+                            // Defer the `not` operation until the end - a != b <=> !(a == b)
+                            let op = if *op == Cmpop::NotEq { Cmpop::Eq } else { *op };
+
+                            let cmp = gen_cmpop_expr_with_values(
+                                generator,
+                                ctx,
+                                (Some(left_ty), left_elem),
+                                &[op],
+                                &[(Some(right_ty), right_elem)],
+                            )
+                                .transpose()
+                                .unwrap()
+                                .and_then(|v| {
+                                    v.to_basic_value_enum(ctx, generator, ctx.primitives.bool)
+                                })
+                                .map(BasicValueEnum::into_int_value)?;
+
+                            Ok(ctx.builder.build_not(cmp, "").unwrap())
+                        },
+                        |_, ctx| {
+                            let bb = ctx.builder.get_insert_block().unwrap();
+                            cmp_phi.add_incoming(&[(&llvm_i1.const_zero(), bb)]);
+                            ctx.builder.build_unconditional_branch(post_foreach_cmp).unwrap();
+
+                            Ok(())
+                        },
+                        |_, _| Ok(()),
+                    )?;
+                }
+
+                // Length of tuples is checked last as operators do not short-circuit by tuple
+                // length in Python:
+                //
+                // >>> (1, 2) < ("a",)
+                // TypeError: '<' not supported between instances of 'int' and 'str'
+                let bb = ctx.builder.get_insert_block().unwrap();
+                let is_len_eq = llvm_i1.const_int(
+                    u64::from(left_tys.len() == right_tys.len()),
+                    false,
+                );
+                cmp_phi.add_incoming(&[(&is_len_eq, bb)]);
+                ctx.builder.build_unconditional_branch(post_foreach_cmp).unwrap();
+
+                ctx.builder.position_at_end(post_foreach_cmp);
+                let cmp_phi = cmp_phi.as_basic_value().into_int_value();
+
+                // Invert the final value if __ne__
+                if *op == Cmpop::NotEq {
+                    ctx.builder.build_not(cmp_phi, "").unwrap()
+                } else {
+                    cmp_phi
+                }
             } else if [left_ty, right_ty].iter().any(|ty| matches!(&*ctx.unifier.get_ty_immutable(*ty), TypeEnum::TVar { .. })) {
                 if ctx.registry.llvm_options.opt_level == OptimizationLevel::None {
                     ctx.make_assert(