Push prefix printing selectin logic into container resolution
authorMatt Corallo <git@bluematt.me>
Mon, 29 Mar 2021 15:20:42 +0000 (11:20 -0400)
committerMatt Corallo <git@bluematt.me>
Mon, 29 Mar 2021 16:47:11 +0000 (12:47 -0400)
Instead of trying to guess the appropriate prefix printing based on
the types. This has no changes to the generated code.

c-bindings-gen/src/types.rs

index ba916f68c2951b0ed4510d674616fa2bc534cf92..dfc1e4112351193c72142bdd26e41f93b6f1eecc 100644 (file)
@@ -577,6 +577,20 @@ enum EmptyValExpectedTy {
        ReferenceAsPointer,
 }
 
        ReferenceAsPointer,
 }
 
+#[derive(PartialEq)]
+/// Describes the appropriate place to print a general type-conversion string when converting a
+/// container.
+enum ContainerPrefixLocation {
+       /// Prints a general type-conversion string prefix and suffix outside of the
+       /// container-conversion strings.
+       OutsideConv,
+       /// Prints a general type-conversion string prefix and suffix inside of the
+       /// container-conversion strings.
+       PerConv,
+       /// Does not print the usual type-conversion string prefix and suffix.
+       NoPrefix,
+}
+
 impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
        pub fn new(orig_crate: &'a str, module_path: &'a str, types: ImportResolver<'a, 'c>, crate_types: &'a mut CrateTypes<'c>) -> Self {
                Self { orig_crate, module_path, types, crate_types }
 impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
        pub fn new(orig_crate: &'a str, module_path: &'a str, types: ImportResolver<'a, 'c>, crate_types: &'a mut CrateTypes<'c>) -> Self {
                Self { orig_crate, module_path, types, crate_types }
@@ -968,19 +982,19 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
        fn to_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
                        // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
                        // expecting one element in the vec per generic type, each of which is inline-converted
        fn to_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
                        // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
                        // expecting one element in the vec per generic type, each of which is inline-converted
-                       -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
+                       -> Option<(&'b str, Vec<(String, String)>, &'b str, ContainerPrefixLocation)> {
                match full_path {
                        "Result" if !is_ref => {
                                Some(("match ",
                                                vec![(" { Ok(mut o) => crate::c_types::CResultTempl::ok(".to_string(), "o".to_string()),
                                                        (").into(), Err(mut e) => crate::c_types::CResultTempl::err(".to_string(), "e".to_string())],
                match full_path {
                        "Result" if !is_ref => {
                                Some(("match ",
                                                vec![(" { Ok(mut o) => crate::c_types::CResultTempl::ok(".to_string(), "o".to_string()),
                                                        (").into(), Err(mut e) => crate::c_types::CResultTempl::err(".to_string(), "e".to_string())],
-                                               ").into() }"))
+                                               ").into() }", ContainerPrefixLocation::PerConv))
                        },
                        "Vec" if !is_ref => {
                        },
                        "Vec" if !is_ref => {
-                               Some(("Vec::new(); for mut item in ", vec![(format!(".drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
+                               Some(("Vec::new(); for mut item in ", vec![(format!(".drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }", ContainerPrefixLocation::PerConv))
                        },
                        "Slice" => {
                        },
                        "Slice" => {
-                               Some(("Vec::new(); for item in ", vec![(format!(".iter() {{ local_{}.push(", var_name), "**item".to_string())], "); }"))
+                               Some(("Vec::new(); for item in ", vec![(format!(".iter() {{ local_{}.push(", var_name), "**item".to_string())], "); }", ContainerPrefixLocation::PerConv))
                        },
                        "Option" => {
                                if let Some(syn::Type::Path(p)) = single_contained {
                        },
                        "Option" => {
                                if let Some(syn::Type::Path(p)) = single_contained {
@@ -988,11 +1002,11 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                if is_ref {
                                                        return Some(("if ", vec![
                                                                (".is_none() { std::ptr::null() } else { ".to_owned(), format!("({}.as_ref().unwrap())", var_access))
                                                if is_ref {
                                                        return Some(("if ", vec![
                                                                (".is_none() { std::ptr::null() } else { ".to_owned(), format!("({}.as_ref().unwrap())", var_access))
-                                                               ], " }"));
+                                                               ], " }", ContainerPrefixLocation::OutsideConv));
                                                } else {
                                                        return Some(("if ", vec![
                                                                (".is_none() { std::ptr::null_mut() } else { ".to_owned(), format!("({}.unwrap())", var_access))
                                                } else {
                                                        return Some(("if ", vec![
                                                                (".is_none() { std::ptr::null_mut() } else { ".to_owned(), format!("({}.unwrap())", var_access))
-                                                               ], " }"));
+                                                               ], " }", ContainerPrefixLocation::OutsideConv));
                                                }
                                        }
                                }
                                                }
                                        }
                                }
@@ -1002,7 +1016,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                        let s = String::from_utf8(v).unwrap();
                                        return Some(("if ", vec![
                                                (format!(".is_none() {{ {} }} else {{ ", s), format!("({}.unwrap())", var_access))
                                        let s = String::from_utf8(v).unwrap();
                                        return Some(("if ", vec![
                                                (format!(".is_none() {{ {} }} else {{ ", s), format!("({}.unwrap())", var_access))
-                                               ], " }"));
+                                               ], " }", ContainerPrefixLocation::PerConv));
                                } else { unreachable!(); }
                        },
                        _ => None,
                                } else { unreachable!(); }
                        },
                        _ => None,
@@ -1014,27 +1028,27 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
        fn from_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
                        // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
                        // expecting one element in the vec per generic type, each of which is inline-converted
        fn from_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
                        // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
                        // expecting one element in the vec per generic type, each of which is inline-converted
-                       -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
+                       -> Option<(&'b str, Vec<(String, String)>, &'b str, ContainerPrefixLocation)> {
                match full_path {
                        "Result" if !is_ref => {
                                Some(("match ",
                                                vec![(".result_ok { true => Ok(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.result)) }})", var_access)),
                                                     ("), false => Err(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.err)) }})", var_access))],
                match full_path {
                        "Result" if !is_ref => {
                                Some(("match ",
                                                vec![(".result_ok { true => Ok(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.result)) }})", var_access)),
                                                     ("), false => Err(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.err)) }})", var_access))],
-                                               ")}"))
-                       },
-                       "Vec"|"Slice" if !is_ref => {
-                               Some(("Vec::new(); for mut item in ", vec![(format!(".into_rust().drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
+                                               ")}", ContainerPrefixLocation::PerConv))
                        },
                        "Slice" if is_ref => {
                        },
                        "Slice" if is_ref => {
-                               Some(("Vec::new(); for mut item in ", vec![(format!(".as_slice().iter() {{ local_{}.push(", var_name), "item".to_string())], "); }"))
+                               Some(("Vec::new(); for mut item in ", vec![(format!(".as_slice().iter() {{ local_{}.push(", var_name), "item".to_string())], "); }", ContainerPrefixLocation::PerConv))
+                       },
+                       "Vec"|"Slice" => {
+                               Some(("Vec::new(); for mut item in ", vec![(format!(".into_rust().drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }", ContainerPrefixLocation::PerConv))
                        },
                        "Option" => {
                                if let Some(syn::Type::Path(p)) = single_contained {
                                        if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
                                                if is_ref {
                        },
                        "Option" => {
                                if let Some(syn::Type::Path(p)) = single_contained {
                                        if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
                                                if is_ref {
-                                                       return Some(("if ", vec![(".inner.is_null() { None } else { Some((*".to_string(), format!("{}", var_access))], ").clone()) }"))
+                                                       return Some(("if ", vec![(".inner.is_null() { None } else { Some((*".to_string(), format!("{}", var_access))], ").clone()) }", ContainerPrefixLocation::PerConv))
                                                } else {
                                                } else {
-                                                       return Some(("if ", vec![(".inner.is_null() { None } else { Some(".to_string(), format!("{}", var_access))], ") }"));
+                                                       return Some(("if ", vec![(".inner.is_null() { None } else { Some(".to_string(), format!("{}", var_access))], ") }", ContainerPrefixLocation::PerConv));
                                                }
                                        }
                                }
                                                }
                                        }
                                }
@@ -1047,15 +1061,15 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                EmptyValExpectedTy::ReferenceAsPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ &mut *{} }}", var_access))
                                                EmptyValExpectedTy::ReferenceAsPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ &mut *{} }}", var_access))
-                                                       ], ") }")),
+                                                       ], ") }", ContainerPrefixLocation::NoPrefix)),
                                                EmptyValExpectedTy::OwnedPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ *Box::from_raw({}) }}", var_access))
                                                EmptyValExpectedTy::OwnedPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ *Box::from_raw({}) }}", var_access))
-                                                       ], ") }")),
+                                                       ], ") }", ContainerPrefixLocation::NoPrefix)),
                                                EmptyValExpectedTy::NonPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("{}", var_access))
                                                EmptyValExpectedTy::NonPointer =>
                                                        return Some(("if ", vec![
                                                                (format!("{} {{ None }} else {{ Some(", s), format!("{}", var_access))
-                                                       ], ") }")),
+                                                       ], ") }", ContainerPrefixLocation::PerConv)),
                                        }
                                } else { unreachable!(); }
                        },
                                        }
                                } else { unreachable!(); }
                        },
@@ -1563,7 +1577,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
 
        fn write_conversion_new_var_intern<'b, W: std::io::Write,
                LP: Fn(&str, bool) -> Option<(&str, &str)>,
 
        fn write_conversion_new_var_intern<'b, W: std::io::Write,
                LP: Fn(&str, bool) -> Option<(&str, &str)>,
-               LC: Fn(&str, bool, Option<&syn::Type>, &syn::Ident, &str) ->  Option<(&'b str, Vec<(String, String)>, &'b str)>,
+               LC: Fn(&str, bool, Option<&syn::Type>, &syn::Ident, &str) ->  Option<(&'b str, Vec<(String, String)>, &'b str, ContainerPrefixLocation)>,
                VP: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool),
                VS: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool)>
                        (&self, w: &mut W, ident: &syn::Ident, var: &str, t: &syn::Type, generics: Option<&GenericTypes>,
                VP: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool),
                VS: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool)>
                        (&self, w: &mut W, ident: &syn::Ident, var: &str, t: &syn::Type, generics: Option<&GenericTypes>,
@@ -1575,7 +1589,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                // For slices (and Options), we refuse to directly map them as is_ref when they
                                // aren't opaque types containing an inner pointer. This is due to the fact that,
                                // in both cases, the actual higher-level type is non-is_ref.
                                // For slices (and Options), we refuse to directly map them as is_ref when they
                                // aren't opaque types containing an inner pointer. This is due to the fact that,
                                // in both cases, the actual higher-level type is non-is_ref.
-                               let ty_has_inner = if self.is_transparent_container(&$container_type, is_ref) || $container_type == "Slice" {
+                               let ty_has_inner = if $args_len == 1 {
                                        let ty = $args_iter().next().unwrap();
                                        if $container_type == "Slice" && to_c {
                                                // "To C ptr_for_ref" means "return the regular object with is_owned
                                        let ty = $args_iter().next().unwrap();
                                        if $container_type == "Slice" && to_c {
                                                // "To C ptr_for_ref" means "return the regular object with is_owned
@@ -1599,7 +1613,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                let mut only_contained_type = None;
                                let mut only_contained_has_inner = false;
                                let mut contains_slice = false;
                                let mut only_contained_type = None;
                                let mut only_contained_has_inner = false;
                                let mut contains_slice = false;
-                               if $args_len == 1 && self.is_transparent_container(&$container_type, is_ref) {
+                               if $args_len == 1 {
                                        only_contained_has_inner = ty_has_inner;
                                        let arg = $args_iter().next().unwrap();
                                        if let syn::Type::Reference(t) = arg {
                                        only_contained_has_inner = ty_has_inner;
                                        let arg = $args_iter().next().unwrap();
                                        if let syn::Type::Reference(t) = arg {
@@ -1609,16 +1623,19 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                } else if let syn::Type::Slice(_) = &*t.elem {
                                                        contains_slice = true;
                                                } else { return false; }
                                                } else if let syn::Type::Slice(_) = &*t.elem {
                                                        contains_slice = true;
                                                } else { return false; }
-                                               needs_ref_map = true;
-                                       } else if let syn::Type::Path(_) = arg {
+                                               // If the inner element contains an inner pointer, we will just use that,
+                                               // avoiding the need to map elements to references. Otherwise we'll need to
+                                               // do an extra mapping step.
+                                               needs_ref_map = !only_contained_has_inner;
+                                       } else {
                                                only_contained_type = Some(&arg);
                                                only_contained_type = Some(&arg);
-                                       } else { unimplemented!(); }
+                                       }
                                }
 
                                }
 
-                               if let Some((prefix, conversions, suffix)) = container_lookup(&$container_type, is_ref && ty_has_inner, only_contained_type, ident, var) {
+                               if let Some((prefix, conversions, suffix, prefix_location)) = container_lookup(&$container_type, is_ref && ty_has_inner, only_contained_type, ident, var) {
                                        assert_eq!(conversions.len(), $args_len);
                                        write!(w, "let mut local_{}{} = ", ident, if !to_c && needs_ref_map {"_base"} else { "" }).unwrap();
                                        assert_eq!(conversions.len(), $args_len);
                                        write!(w, "let mut local_{}{} = ", ident, if !to_c && needs_ref_map {"_base"} else { "" }).unwrap();
-                                       if only_contained_has_inner && to_c {
+                                       if prefix_location == ContainerPrefixLocation::OutsideConv {
                                                var_prefix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
                                        }
                                        write!(w, "{}{}", prefix, var).unwrap();
                                                var_prefix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
                                        }
                                        write!(w, "{}{}", prefix, var).unwrap();
@@ -1635,24 +1652,23 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                let new_var = self.write_conversion_new_var_intern(w, &syn::Ident::new(&new_var_name, Span::call_site()),
                                                                &var_access, conv_ty, generics, contains_slice || (is_ref && ty_has_inner), ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix);
                                                if new_var { write!(w, " ").unwrap(); }
                                                let new_var = self.write_conversion_new_var_intern(w, &syn::Ident::new(&new_var_name, Span::call_site()),
                                                                &var_access, conv_ty, generics, contains_slice || (is_ref && ty_has_inner), ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix);
                                                if new_var { write!(w, " ").unwrap(); }
-                                               if (!only_contained_has_inner || !to_c) && !contains_slice {
-                                                       var_prefix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
-                                               }
 
 
-                                               if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
+                                               if prefix_location == ContainerPrefixLocation::PerConv {
+                                                       var_prefix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
+                                               } else if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
                                                        write!(w, "Box::into_raw(Box::new(").unwrap();
                                                }
                                                        write!(w, "Box::into_raw(Box::new(").unwrap();
                                                }
+
                                                write!(w, "{}{}", if contains_slice { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
                                                write!(w, "{}{}", if contains_slice { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
-                                               if (!only_contained_has_inner || !to_c) && !contains_slice {
+                                               if prefix_location == ContainerPrefixLocation::PerConv {
                                                        var_suffix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
                                                        var_suffix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
-                                               }
-                                               if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
+                                               } else if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
                                                        write!(w, "))").unwrap();
                                                }
                                                write!(w, " }}").unwrap();
                                        }
                                        write!(w, "{}", suffix).unwrap();
                                                        write!(w, "))").unwrap();
                                                }
                                                write!(w, " }}").unwrap();
                                        }
                                        write!(w, "{}", suffix).unwrap();
-                                       if only_contained_has_inner && to_c {
+                                       if prefix_location == ContainerPrefixLocation::OutsideConv {
                                                var_suffix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
                                        }
                                        write!(w, ";").unwrap();
                                                var_suffix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
                                        }
                                        write!(w, ";").unwrap();