fix compiler

Author: ZuseZ4

compiler/rustc_builtin_macros/src/autodiff.rs

@@ -607,23 +607,30 @@ mod llvm_enzyme {
                 exprs = ecx.expr_call(new_decl_span, bb_call_expr, thin_vec![default_call_expr]);
             }
         } else if x.mode.is_rev() {
-            //if x.width == 1 {
-            //    if primal_ret {
-            //        // We have extra handling above for the primal ret
-            //        d_ret_ty = d_ret_ty[1..].to_vec().into();
-            //    }
-
-            //    for arg in d_ret_ty.iter() {
-            //        let arg = arg.kind.is_simple_path().unwrap();
-            //        let sl: Vec<Symbol> = vec![arg, kw::Default];
-            //        let tmp = ecx.def_site_path(&sl);
-            //        let default_call_expr = ecx.expr_path(ecx.path(span, tmp));
-            //        let default_call_expr =
-            //            ecx.expr_call(new_decl_span, default_call_expr, thin_vec![]);
-            //        exprs = default_call_expr;
-            //        //exprs.push(default_call_expr);
-            //    }
-            //}
+            if x.width == 1 {
+                // We either have `-> ArbitraryType` or `-> (ArbitraryType, repeated_float_scalars)`.
+                match d_ret_ty.kind {
+                    TyKind::Tup(ref args) => {
+                        // We have a tuple return type. We need to create a tuple of the same size
+                        // and fill it with default values.
+                        let mut exprs2 = thin_vec![exprs];
+                        for arg in args.iter().skip(1) {
+                            let arg = arg.kind.is_simple_path().unwrap();
+                            let sl: Vec<Symbol> = vec![arg, kw::Default];
+                            let tmp = ecx.def_site_path(&sl);
+                            let default_call_expr = ecx.expr_path(ecx.path(span, tmp));
+                            let default_call_expr =
+                                ecx.expr_call(new_decl_span, default_call_expr, thin_vec![]);
+                            exprs2.push(default_call_expr);
+                        }
+                        exprs = ecx.expr_tuple(new_decl_span, exprs2);
+                    }
+                    _ => {
+                        panic!("Unsupported return type: {:?}", d_ret_ty);
+                    }
+                }
+            }
+            exprs = ecx.expr_call(new_decl_span, bb_call_expr, thin_vec![exprs]);
         } else {
             // The return type of our dummy function is the same as the return type of our primal.
             // In that case, we can just use the primal call as last instruction.

compiler/rustc_codegen_llvm/src/builder/autodiff.rs

@@ -3,7 +3,7 @@ use std::ptr;
 use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, AutoDiffItem, DiffActivity, DiffMode};
 use rustc_codegen_ssa::ModuleCodegen;
 use rustc_codegen_ssa::back::write::ModuleConfig;
-use rustc_errors::{DiagCtxt, FatalError};
+use rustc_errors::FatalError;
 use rustc_middle::bug;
 use tracing::{debug, trace};
 

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -1,9 +1,7 @@
 use std::str::FromStr;
 
 use rustc_abi::ExternAbi;
-use rustc_ast::expand::autodiff_attrs::{
-    AutoDiffAttrs, DiffActivity, DiffMode, valid_input_activity, valid_ret_activity,
-};
+use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, DiffActivity, DiffMode};
 use rustc_ast::{LitKind, MetaItem, MetaItemInner, attr};
 use rustc_attr_parsing::ReprAttr::ReprAlign;
 use rustc_attr_parsing::{AttributeKind, InlineAttr, InstructionSetAttr, OptimizeAttr};
@@ -887,15 +885,6 @@ fn autodiff_attrs(tcx: TyCtxt<'_>, id: DefId) -> Option<AutoDiffAttrs> {
         }
     }
 
-    for &input in &arg_activities {
-        if !valid_input_activity(mode, input) {
-            span_bug!(attr.span(), "Invalid input activity {} for {} mode", input, mode);
-        }
-    }
-    if !valid_ret_activity(mode, ret_activity) {
-        span_bug!(attr.span(), "Invalid return activity {} for {} mode", ret_activity, mode);
-    }
-
     Some(AutoDiffAttrs { mode, width, ret_activity, input_activity: arg_activities })
 }