Remove lifetime from impl blocks; add to fns.

Previously we parameterized some impl blocks by <'a>.
Instead, parameterize each function individually.

Author: adetaylor

engine/src/conversion/api.rs

@@ -719,10 +719,3 @@ impl<T: AnalysisPhase> Api<T> {
         Ok(Box::new(std::iter::once(Api::Enum { name, item })))
     }
 }
-
-/// Whether a type is a pointer of some kind.
-pub(crate) enum Pointerness {
-    Not,
-    ConstPtr,
-    MutPtr,
-}

engine/src/conversion/codegen_cpp/function_wrapper_cpp.rs

@@ -10,7 +10,6 @@ use syn::{Type, TypePtr};
 
 use crate::conversion::{
     analysis::fun::function_wrapper::{CppConversionType, TypeConversionPolicy},
-    api::Pointerness,
     ConvertErrorFromCpp,
 };
 
@@ -63,17 +62,6 @@ impl TypeConversionPolicy {
         cpp_name_map.type_to_cpp(self.cxxbridge_type())
     }
 
-    pub(crate) fn is_a_pointer(&self) -> Pointerness {
-        match self.cxxbridge_type() {
-            Type::Ptr(TypePtr {
-                mutability: Some(_),
-                ..
-            }) => Pointerness::MutPtr,
-            Type::Ptr(_) => Pointerness::ConstPtr,
-            _ => Pointerness::Not,
-        }
-    }
-
     fn unique_ptr_wrapped_type(
         &self,
         original_name_map: &CppNameMap,

engine/src/conversion/codegen_rs/fun_codegen.rs

@@ -6,7 +6,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use autocxx_parser::IncludeCppConfig;
 use indexmap::set::IndexSet as HashSet;
 use std::borrow::Cow;
 
@@ -24,15 +23,15 @@ use super::{
     function_wrapper_rs::RustParamConversion,
     maybe_unsafes_to_tokens,
     unqualify::{unqualify_params, unqualify_ret_type},
-    ImplBlockDetails, ImplBlockKey, MaybeUnsafeStmt, RsCodegenResult, TraitImplBlockDetails, Use,
+    ImplBlockDetails, MaybeUnsafeStmt, RsCodegenResult, TraitImplBlockDetails, Use,
 };
 use crate::{
     conversion::{
         analysis::fun::{
             function_wrapper::TypeConversionPolicy, ArgumentAnalysis, FnAnalysis, FnKind,
             MethodKind, RustRenameStrategy, TraitMethodDetails,
         },
-        api::{Pointerness, UnsafetyNeeded},
+        api::UnsafetyNeeded,
     },
     minisyn::minisynize_vec,
     types::{Namespace, QualifiedName},
@@ -91,13 +90,13 @@ pub(super) fn gen_function(
     analysis: FnAnalysis,
     cpp_call_name: String,
     non_pod_types: &HashSet<QualifiedName>,
-    config: &IncludeCppConfig,
 ) -> RsCodegenResult {
     if analysis.ignore_reason.is_err() || !analysis.externally_callable {
         return RsCodegenResult::default();
     }
     let cxxbridge_name = analysis.cxxbridge_name;
     let rust_name = &analysis.rust_name;
+    eprintln!("GENERATING {rust_name}");
     let ret_type = analysis.ret_type;
     let ret_conversion = analysis.ret_conversion;
     let param_details = analysis.param_details;
@@ -125,7 +124,6 @@ pub(super) fn gen_function(
         non_pod_types,
         ret_type: &ret_type,
         ret_conversion: &ret_conversion,
-        reference_wrappers: config.unsafe_policy.requires_cpprefs(),
     };
     // In rare occasions, we might need to give an explicit lifetime.
     let (lifetime_tokens, params, ret_type) = add_explicit_lifetime_if_necessary(
@@ -239,7 +237,6 @@ struct FnGenerator<'a> {
     always_unsafe_due_to_trait_definition: bool,
     doc_attrs: &'a Vec<Attribute>,
     non_pod_types: &'a HashSet<QualifiedName>,
-    reference_wrappers: bool,
 }
 
 impl<'a> FnGenerator<'a> {
@@ -396,39 +393,15 @@ impl<'a> FnGenerator<'a> {
         let rust_name = make_ident(self.rust_name);
         let unsafety = self.unsafety.wrapper_token();
         let doc_attrs = self.doc_attrs;
-        let receiver_pointerness = self
-            .param_details
-            .iter()
-            .next()
-            .map(|pd| pd.conversion.is_a_pointer())
-            .unwrap_or(Pointerness::Not);
         let ty = impl_block_type_name.get_final_ident();
-        let ty = match receiver_pointerness {
-            Pointerness::MutPtr if self.reference_wrappers => ImplBlockKey {
-                ty: parse_quote! {
-                    #ty
-                },
-                lifetime: Some(parse_quote! { 'a }),
-            },
-            Pointerness::ConstPtr if self.reference_wrappers => ImplBlockKey {
-                ty: parse_quote! {
-                    #ty
-                },
-                lifetime: Some(parse_quote! { 'a }),
-            },
-            _ => ImplBlockKey {
-                ty: parse_quote! { # ty },
-                lifetime: None,
-            },
-        };
         Box::new(ImplBlockDetails {
             item: ImplItem::Fn(parse_quote! {
                 #(#doc_attrs)*
                 pub #unsafety fn #rust_name #lifetime_tokens ( #wrapper_params ) #ret_type {
                     #call_body
                 }
             }),
-            ty,
+            ty: parse_quote! { # ty },
         })
     }
 
@@ -471,7 +444,7 @@ impl<'a> FnGenerator<'a> {
         };
         Box::new(ImplBlockDetails {
             item: ImplItem::Fn(parse_quote! { #stuff }),
-            ty: ImplBlockKey { ty, lifetime: None },
+            ty,
         })
     }
 

engine/src/conversion/codegen_rs/lifetime.rs

@@ -32,7 +32,7 @@ use syn::{
 ///    built-in type
 /// 3) Any parameter is any form of reference, and we're returning an `impl New`
 ///    3a) an 'impl ValueParam' counts as a reference.
-/// 4) If we're using CppRef<'a, T> as a return type
+/// 4) If we're using CppRef<'a, T> as a param or return type
 pub(crate) fn add_explicit_lifetime_if_necessary<'r>(
     param_details: &[ArgumentAnalysis],
     mut params: Punctuated<FnArg, Comma>,
@@ -56,6 +56,13 @@ pub(crate) fn add_explicit_lifetime_if_necessary<'r>(
                 RustConversionType::FromValueParamToPtr
             )
     });
+
+    let any_param_is_cppref = param_details.iter().any(|pd| {
+        matches!(
+            pd.conversion.rust_conversion,
+            RustConversionType::FromReferenceWrapperToPointer
+        )
+    });
     let return_type_is_impl = return_type_is_impl(&ret_type);
     let return_type_is_cppref = matches!(
         ret_conversion,
@@ -71,7 +78,8 @@ pub(crate) fn add_explicit_lifetime_if_necessary<'r>(
     if !(has_mutable_receiver
         || hits_1024_bug
         || returning_impl_with_a_reference_param
-        || return_type_is_cppref)
+        || return_type_is_cppref
+        || any_param_is_cppref)
     {
         return (None, params, ret_type);
     }
@@ -97,18 +105,15 @@ pub(crate) fn add_explicit_lifetime_if_necessary<'r>(
                     #rarrow #old_tyit + 'a
                 })
             }
-            Type::Ptr(_) if return_type_is_cppref => {
-                // The ptr will be converted to CppRef<'a, T> elsewhere, so we
-                // just need to return the return type as-is such that the
-                // next match statement adds <'a> to the function.
-                Some(ret_type.clone().into_owned())
-            }
             _ => None,
         },
         _ => None,
     };
 
     match new_return_type {
+        None if return_type_is_cppref || any_param_is_cppref => {
+            (Some(quote! { <'a> }), params, ret_type)
+        }
         None => (None, params, ret_type),
         Some(new_return_type) => {
             for FnArg::Typed(PatType { ty, .. }) | FnArg::Receiver(syn::Receiver { ty, .. }) in

engine/src/conversion/codegen_rs/mod.rs

@@ -23,8 +23,7 @@ use itertools::Itertools;
 use proc_macro2::{Span, TokenStream};
 use syn::{
     parse_quote, punctuated::Punctuated, token::Comma, Attribute, Expr, FnArg, ForeignItem,
-    ForeignItemFn, Ident, ImplItem, Item, ItemForeignMod, ItemMod, Lifetime, TraitItem, Type,
-    TypePath,
+    ForeignItemFn, Ident, ImplItem, Item, ItemForeignMod, ItemMod, TraitItem, Type, TypePath,
 };
 
 use crate::{
@@ -59,16 +58,10 @@ use super::{
 use super::{convert_error::ErrorContext, ConvertErrorFromCpp};
 use quote::quote;
 
-#[derive(Clone, Hash, PartialEq, Eq)]
-struct ImplBlockKey {
-    ty: Type,
-    lifetime: Option<Lifetime>,
-}
-
 /// An entry which needs to go into an `impl` block for a given type.
 struct ImplBlockDetails {
     item: ImplItem,
-    ty: ImplBlockKey,
+    ty: Type,
 }
 
 struct TraitImplBlockDetails {
@@ -412,10 +405,8 @@ impl<'a> RsCodeGenerator<'a> {
             }
         }
         for (ty, entries) in impl_entries_by_type.into_iter() {
-            let lt = ty.lifetime.map(|lt| quote! { < #lt > });
-            let ty = ty.ty;
             output_items.push(Item::Impl(parse_quote! {
-                impl #lt #ty {
+                impl #ty {
                     #(#entries)*
                 }
             }))
@@ -494,7 +485,6 @@ impl<'a> RsCodeGenerator<'a> {
                 analysis,
                 cpp_call_name,
                 non_pod_types,
-                self.config,
             ),
             Api::Const { const_item, .. } => RsCodegenResult {
                 bindgen_mod_items: vec![Item::Const(const_item.into())],
@@ -1095,10 +1085,7 @@ impl<'a> RsCodeGenerator<'a> {
                         fn #method(_uhoh: autocxx::BindingGenerationFailure) {
                         }
                     },
-                    ty: ImplBlockKey {
-                        ty: parse_quote! { #self_ty },
-                        lifetime: None,
-                    },
+                    ty: parse_quote! { #self_ty },
                 })),
                 None,
                 None,