Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 874 insertions, 0 deletions

diff --git a/third_party/rust/derive_arbitrary/.cargo-checksum.json b/third_party/rust/derive_arbitrary/.cargo-checksum.json
new file mode 100644
index 0000000000..95cc15121a
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"f1778460809aaf6ac901ebb08f73bde6776318f85be107ab632d855140fea183","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"15656cc11a8331f28c0986b8ab97220d3e76f98e60ed388b5ffad37dfac4710c","README.md":"7059db284b2016ba7355c63a2b14eb732c7b8952286ff1bc4fdde605018a39c4","src/container_attributes.rs":"9342a89e5e5f412159d1a1a88ae4ee0248180f30adc13e61ebf5f96b5f09877f","src/field_attributes.rs":"15093171d7f1e30c2b2523788e54c69c816029b310133ceb1ac811d1f11a76d5","src/lib.rs":"701a9c66e25c3a2151eab9159f6c2fa64ea910ceb6feb225dc97c2734254c265"},"package":"53e0efad4403bfc52dc201159c4b842a246a14b98c64b55dfd0f2d89729dfeb8"}
\ No newline at end of file
diff --git a/third_party/rust/derive_arbitrary/Cargo.toml b/third_party/rust/derive_arbitrary/Cargo.toml
new file mode 100644
index 0000000000..3396129b6d
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/Cargo.toml
@@ -0,0 +1,52 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.63.0"
+name = "derive_arbitrary"
+version = "1.3.1"
+authors = [
+    "The Rust-Fuzz Project Developers",
+    "Nick Fitzgerald <fitzgen@gmail.com>",
+    "Manish Goregaokar <manishsmail@gmail.com>",
+    "Andre Bogus <bogusandre@gmail.com>",
+    "Corey Farwell <coreyf@rwell.org>",
+]
+description = "Derives arbitrary traits"
+documentation = "https://docs.rs/arbitrary/"
+readme = "README.md"
+keywords = [
+    "arbitrary",
+    "testing",
+    "derive",
+    "macro",
+]
+categories = ["development-tools::testing"]
+license = "MIT/Apache-2.0"
+repository = "https://github.com/rust-fuzz/arbitrary"
+resolver = "1"
+
+[lib]
+proc_macro = true
+
+[dependencies.proc-macro2]
+version = "1.0"
+
+[dependencies.quote]
+version = "1.0"
+
+[dependencies.syn]
+version = "2"
+features = [
+    "derive",
+    "parsing",
+]
diff --git a/third_party/rust/derive_arbitrary/LICENSE-APACHE b/third_party/rust/derive_arbitrary/LICENSE-APACHE
new file mode 100644
index 0000000000..16fe87b06e
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
+   publicly display, publicly perform, sublicense, and distribute the
+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
+   the brackets!)  The text should be enclosed in the appropriate
+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
+   identification within third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/third_party/rust/derive_arbitrary/LICENSE-MIT b/third_party/rust/derive_arbitrary/LICENSE-MIT
new file mode 100644
index 0000000000..d74f9e93d4
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/LICENSE-MIT
@@ -0,0 +1,27 @@
+MIT License
+
+Copyright (c) 2019 Manish Goregaokar
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/derive_arbitrary/README.md b/third_party/rust/derive_arbitrary/README.md
new file mode 100644
index 0000000000..7f48c75de1
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/README.md
@@ -0,0 +1,7 @@
+# `#[derive(Arbitrary)]`
+
+This crate implements support for automatically deriving [the `Arbitrary`
+trait](https://docs.rs/arbitrary/*/arbitrary/trait.Arbitrary.html).
+
+Don't depend on this crate directly, though. Instead, enable the `"derive"`
+feature of the `arbitrary` crate.
diff --git a/third_party/rust/derive_arbitrary/src/container_attributes.rs b/third_party/rust/derive_arbitrary/src/container_attributes.rs
new file mode 100644
index 0000000000..269131c884
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/src/container_attributes.rs
@@ -0,0 +1,78 @@
+use crate::ARBITRARY_ATTRIBUTE_NAME;
+use syn::{
+    parse::Error, punctuated::Punctuated, DeriveInput, Expr, ExprLit, Lit, Meta, MetaNameValue,
+    Token, TypeParam,
+};
+
+pub struct ContainerAttributes {
+    /// Specify type bounds to be applied to the derived `Arbitrary` implementation instead of the
+    /// default inferred bounds.
+    ///
+    /// ```ignore
+    /// #[arbitrary(bound = "T: Default, U: Debug")]
+    /// ```
+    ///
+    /// Multiple attributes will be combined as long as they don't conflict, e.g.
+    ///
+    /// ```ignore
+    /// #[arbitrary(bound = "T: Default")]
+    /// #[arbitrary(bound = "U: Default")]
+    /// ```
+    pub bounds: Option<Vec<Punctuated<TypeParam, Token![,]>>>,
+}
+
+impl ContainerAttributes {
+    pub fn from_derive_input(derive_input: &DeriveInput) -> Result<Self, Error> {
+        let mut bounds = None;
+
+        for attr in &derive_input.attrs {
+            if !attr.path().is_ident(ARBITRARY_ATTRIBUTE_NAME) {
+                continue;
+            }
+
+            let meta_list = match attr.meta {
+                Meta::List(ref l) => l,
+                _ => {
+                    return Err(Error::new_spanned(
+                        attr,
+                        format!(
+                            "invalid `{}` attribute. expected list",
+                            ARBITRARY_ATTRIBUTE_NAME
+                        ),
+                    ))
+                }
+            };
+
+            for nested_meta in
+                meta_list.parse_args_with(Punctuated::<Meta, Token![,]>::parse_terminated)?
+            {
+                match nested_meta {
+                    Meta::NameValue(MetaNameValue {
+                        path,
+                        value:
+                            Expr::Lit(ExprLit {
+                                lit: Lit::Str(bound_str_lit),
+                                ..
+                            }),
+                        ..
+                    }) if path.is_ident("bound") => {
+                        bounds
+                            .get_or_insert_with(Vec::new)
+                            .push(bound_str_lit.parse_with(Punctuated::parse_terminated)?);
+                    }
+                    _ => {
+                        return Err(Error::new_spanned(
+                            attr,
+                            format!(
+                                "invalid `{}` attribute. expected `bound = \"..\"`",
+                                ARBITRARY_ATTRIBUTE_NAME,
+                            ),
+                        ))
+                    }
+                }
+            }
+        }
+
+        Ok(Self { bounds })
+    }
+}
diff --git a/third_party/rust/derive_arbitrary/src/field_attributes.rs b/third_party/rust/derive_arbitrary/src/field_attributes.rs
new file mode 100644
index 0000000000..9e5922e04b
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/src/field_attributes.rs
@@ -0,0 +1,105 @@
+use crate::ARBITRARY_ATTRIBUTE_NAME;
+use proc_macro2::{Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::{spanned::Spanned, *};
+
+/// Determines how a value for a field should be constructed.
+#[cfg_attr(test, derive(Debug))]
+pub enum FieldConstructor {
+    /// Assume that Arbitrary is defined for the type of this field and use it (default)
+    Arbitrary,
+
+    /// Places `Default::default()` as a field value.
+    Default,
+
+    /// Use custom function or closure to generate a value for a field.
+    With(TokenStream),
+
+    /// Set a field always to the given value.
+    Value(TokenStream),
+}
+
+pub fn determine_field_constructor(field: &Field) -> Result<FieldConstructor> {
+    let opt_attr = fetch_attr_from_field(field)?;
+    let ctor = match opt_attr {
+        Some(attr) => parse_attribute(attr)?,
+        None => FieldConstructor::Arbitrary,
+    };
+    Ok(ctor)
+}
+
+fn fetch_attr_from_field(field: &Field) -> Result<Option<&Attribute>> {
+    let found_attributes: Vec<_> = field
+        .attrs
+        .iter()
+        .filter(|a| {
+            let path = a.path();
+            let name = quote!(#path).to_string();
+            name == ARBITRARY_ATTRIBUTE_NAME
+        })
+        .collect();
+    if found_attributes.len() > 1 {
+        let name = field.ident.as_ref().unwrap();
+        let msg = format!(
+            "Multiple conflicting #[{ARBITRARY_ATTRIBUTE_NAME}] attributes found on field `{name}`"
+        );
+        return Err(syn::Error::new(field.span(), msg));
+    }
+    Ok(found_attributes.into_iter().next())
+}
+
+fn parse_attribute(attr: &Attribute) -> Result<FieldConstructor> {
+    if let Meta::List(ref meta_list) = attr.meta {
+        parse_attribute_internals(meta_list)
+    } else {
+        let msg = format!("#[{ARBITRARY_ATTRIBUTE_NAME}] must contain a group");
+        Err(syn::Error::new(attr.span(), msg))
+    }
+}
+
+fn parse_attribute_internals(meta_list: &MetaList) -> Result<FieldConstructor> {
+    let mut tokens_iter = meta_list.tokens.clone().into_iter();
+    let token = tokens_iter.next().ok_or_else(|| {
+        let msg = format!("#[{ARBITRARY_ATTRIBUTE_NAME}] cannot be empty.");
+        syn::Error::new(meta_list.span(), msg)
+    })?;
+    match token.to_string().as_ref() {
+        "default" => Ok(FieldConstructor::Default),
+        "with" => {
+            let func_path = parse_assigned_value("with", tokens_iter, meta_list.span())?;
+            Ok(FieldConstructor::With(func_path))
+        }
+        "value" => {
+            let value = parse_assigned_value("value", tokens_iter, meta_list.span())?;
+            Ok(FieldConstructor::Value(value))
+        }
+        _ => {
+            let msg = format!("Unknown option for #[{ARBITRARY_ATTRIBUTE_NAME}]: `{token}`");
+            Err(syn::Error::new(token.span(), msg))
+        }
+    }
+}
+
+// Input:
+//     = 2 + 2
+// Output:
+//     2 + 2
+fn parse_assigned_value(
+    opt_name: &str,
+    mut tokens_iter: impl Iterator<Item = TokenTree>,
+    default_span: Span,
+) -> Result<TokenStream> {
+    let eq_sign = tokens_iter.next().ok_or_else(|| {
+        let msg = format!(
+            "Invalid syntax for #[{ARBITRARY_ATTRIBUTE_NAME}], `{opt_name}` is missing assignment."
+        );
+        syn::Error::new(default_span, msg)
+    })?;
+
+    if eq_sign.to_string() == "=" {
+        Ok(tokens_iter.collect())
+    } else {
+        let msg = format!("Invalid syntax for #[{ARBITRARY_ATTRIBUTE_NAME}], expected `=` after `{opt_name}`, got: `{eq_sign}`");
+        Err(syn::Error::new(eq_sign.span(), msg))
+    }
+}
diff --git a/third_party/rust/derive_arbitrary/src/lib.rs b/third_party/rust/derive_arbitrary/src/lib.rs
new file mode 100644
index 0000000000..886bb4924b
--- /dev/null
+++ b/third_party/rust/derive_arbitrary/src/lib.rs
@@ -0,0 +1,403 @@
+extern crate proc_macro;
+
+use proc_macro2::{Span, TokenStream};
+use quote::quote;
+use syn::*;
+
+mod container_attributes;
+mod field_attributes;
+use container_attributes::ContainerAttributes;
+use field_attributes::{determine_field_constructor, FieldConstructor};
+
+static ARBITRARY_ATTRIBUTE_NAME: &str = "arbitrary";
+static ARBITRARY_LIFETIME_NAME: &str = "'arbitrary";
+
+#[proc_macro_derive(Arbitrary, attributes(arbitrary))]
+pub fn derive_arbitrary(tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = syn::parse_macro_input!(tokens as syn::DeriveInput);
+    expand_derive_arbitrary(input)
+        .unwrap_or_else(syn::Error::into_compile_error)
+        .into()
+}
+
+fn expand_derive_arbitrary(input: syn::DeriveInput) -> Result<TokenStream> {
+    let container_attrs = ContainerAttributes::from_derive_input(&input)?;
+
+    let (lifetime_without_bounds, lifetime_with_bounds) =
+        build_arbitrary_lifetime(input.generics.clone());
+
+    let recursive_count = syn::Ident::new(
+        &format!("RECURSIVE_COUNT_{}", input.ident),
+        Span::call_site(),
+    );
+
+    let arbitrary_method =
+        gen_arbitrary_method(&input, lifetime_without_bounds.clone(), &recursive_count)?;
+    let size_hint_method = gen_size_hint_method(&input)?;
+    let name = input.ident;
+
+    // Apply user-supplied bounds or automatic `T: ArbitraryBounds`.
+    let generics = apply_trait_bounds(
+        input.generics,
+        lifetime_without_bounds.clone(),
+        &container_attrs,
+    )?;
+
+    // Build ImplGeneric with a lifetime (https://github.com/dtolnay/syn/issues/90)
+    let mut generics_with_lifetime = generics.clone();
+    generics_with_lifetime
+        .params
+        .push(GenericParam::Lifetime(lifetime_with_bounds));
+    let (impl_generics, _, _) = generics_with_lifetime.split_for_impl();
+
+    // Build TypeGenerics and WhereClause without a lifetime
+    let (_, ty_generics, where_clause) = generics.split_for_impl();
+
+    Ok(quote! {
+        const _: () = {
+            std::thread_local! {
+                #[allow(non_upper_case_globals)]
+                static #recursive_count: std::cell::Cell<u32> = std::cell::Cell::new(0);
+            }
+
+            #[automatically_derived]
+            impl #impl_generics arbitrary::Arbitrary<#lifetime_without_bounds> for #name #ty_generics #where_clause {
+                #arbitrary_method
+                #size_hint_method
+            }
+        };
+    })
+}
+
+// Returns: (lifetime without bounds, lifetime with bounds)
+// Example: ("'arbitrary", "'arbitrary: 'a + 'b")
+fn build_arbitrary_lifetime(generics: Generics) -> (LifetimeParam, LifetimeParam) {
+    let lifetime_without_bounds =
+        LifetimeParam::new(Lifetime::new(ARBITRARY_LIFETIME_NAME, Span::call_site()));
+    let mut lifetime_with_bounds = lifetime_without_bounds.clone();
+
+    for param in generics.params.iter() {
+        if let GenericParam::Lifetime(lifetime_def) = param {
+            lifetime_with_bounds
+                .bounds
+                .push(lifetime_def.lifetime.clone());
+        }
+    }
+
+    (lifetime_without_bounds, lifetime_with_bounds)
+}
+
+fn apply_trait_bounds(
+    mut generics: Generics,
+    lifetime: LifetimeParam,
+    container_attrs: &ContainerAttributes,
+) -> Result<Generics> {
+    // If user-supplied bounds exist, apply them to their matching type parameters.
+    if let Some(config_bounds) = &container_attrs.bounds {
+        let mut config_bounds_applied = 0;
+        for param in generics.params.iter_mut() {
+            if let GenericParam::Type(type_param) = param {
+                if let Some(replacement) = config_bounds
+                    .iter()
+                    .flatten()
+                    .find(|p| p.ident == type_param.ident)
+                {
+                    *type_param = replacement.clone();
+                    config_bounds_applied += 1;
+                } else {
+                    // If no user-supplied bounds exist for this type, delete the original bounds.
+                    // This mimics serde.
+                    type_param.bounds = Default::default();
+                    type_param.default = None;
+                }
+            }
+        }
+        let config_bounds_supplied = config_bounds
+            .iter()
+            .map(|bounds| bounds.len())
+            .sum::<usize>();
+        if config_bounds_applied != config_bounds_supplied {
+            return Err(Error::new(
+                Span::call_site(),
+                format!(
+                    "invalid `{}` attribute. too many bounds, only {} out of {} are applicable",
+                    ARBITRARY_ATTRIBUTE_NAME, config_bounds_applied, config_bounds_supplied,
+                ),
+            ));
+        }
+        Ok(generics)
+    } else {
+        // Otherwise, inject a `T: Arbitrary` bound for every parameter.
+        Ok(add_trait_bounds(generics, lifetime))
+    }
+}
+
+// Add a bound `T: Arbitrary` to every type parameter T.
+fn add_trait_bounds(mut generics: Generics, lifetime: LifetimeParam) -> Generics {
+    for param in generics.params.iter_mut() {
+        if let GenericParam::Type(type_param) = param {
+            type_param
+                .bounds
+                .push(parse_quote!(arbitrary::Arbitrary<#lifetime>));
+        }
+    }
+    generics
+}
+
+fn with_recursive_count_guard(
+    recursive_count: &syn::Ident,
+    expr: impl quote::ToTokens,
+) -> impl quote::ToTokens {
+    quote! {
+        let guard_against_recursion = u.is_empty();
+        if guard_against_recursion {
+            #recursive_count.with(|count| {
+                if count.get() > 0 {
+                    return Err(arbitrary::Error::NotEnoughData);
+                }
+                count.set(count.get() + 1);
+                Ok(())
+            })?;
+        }
+
+        let result = (|| { #expr })();
+
+        if guard_against_recursion {
+            #recursive_count.with(|count| {
+                count.set(count.get() - 1);
+            });
+        }
+
+        result
+    }
+}
+
+fn gen_arbitrary_method(
+    input: &DeriveInput,
+    lifetime: LifetimeParam,
+    recursive_count: &syn::Ident,
+) -> Result<TokenStream> {
+    fn arbitrary_structlike(
+        fields: &Fields,
+        ident: &syn::Ident,
+        lifetime: LifetimeParam,
+        recursive_count: &syn::Ident,
+    ) -> Result<TokenStream> {
+        let arbitrary = construct(fields, |_idx, field| gen_constructor_for_field(field))?;
+        let body = with_recursive_count_guard(recursive_count, quote! { Ok(#ident #arbitrary) });
+
+        let arbitrary_take_rest = construct_take_rest(fields)?;
+        let take_rest_body =
+            with_recursive_count_guard(recursive_count, quote! { Ok(#ident #arbitrary_take_rest) });
+
+        Ok(quote! {
+            fn arbitrary(u: &mut arbitrary::Unstructured<#lifetime>) -> arbitrary::Result<Self> {
+                #body
+            }
+
+            fn arbitrary_take_rest(mut u: arbitrary::Unstructured<#lifetime>) -> arbitrary::Result<Self> {
+                #take_rest_body
+            }
+        })
+    }
+
+    let ident = &input.ident;
+    let output = match &input.data {
+        Data::Struct(data) => arbitrary_structlike(&data.fields, ident, lifetime, recursive_count)?,
+        Data::Union(data) => arbitrary_structlike(
+            &Fields::Named(data.fields.clone()),
+            ident,
+            lifetime,
+            recursive_count,
+        )?,
+        Data::Enum(data) => {
+            let variants: Vec<TokenStream> = data
+                .variants
+                .iter()
+                .enumerate()
+                .map(|(i, variant)| {
+                    let idx = i as u64;
+                    let variant_name = &variant.ident;
+                    construct(&variant.fields, |_, field| gen_constructor_for_field(field))
+                        .map(|ctor| quote! { #idx => #ident::#variant_name #ctor })
+                })
+                .collect::<Result<_>>()?;
+
+            let variants_take_rest: Vec<TokenStream> = data
+                .variants
+                .iter()
+                .enumerate()
+                .map(|(i, variant)| {
+                    let idx = i as u64;
+                    let variant_name = &variant.ident;
+                    construct_take_rest(&variant.fields)
+                        .map(|ctor| quote! { #idx => #ident::#variant_name #ctor })
+                })
+                .collect::<Result<_>>()?;
+
+            let count = data.variants.len() as u64;
+
+            let arbitrary = with_recursive_count_guard(
+                recursive_count,
+                quote! {
+                    // Use a multiply + shift to generate a ranged random number
+                    // with slight bias. For details, see:
+                    // https://lemire.me/blog/2016/06/30/fast-random-shuffling
+                    Ok(match (u64::from(<u32 as arbitrary::Arbitrary>::arbitrary(u)?) * #count) >> 32 {
+                        #(#variants,)*
+                        _ => unreachable!()
+                    })
+                },
+            );
+
+            let arbitrary_take_rest = with_recursive_count_guard(
+                recursive_count,
+                quote! {
+                    // Use a multiply + shift to generate a ranged random number
+                    // with slight bias. For details, see:
+                    // https://lemire.me/blog/2016/06/30/fast-random-shuffling
+                    Ok(match (u64::from(<u32 as arbitrary::Arbitrary>::arbitrary(&mut u)?) * #count) >> 32 {
+                        #(#variants_take_rest,)*
+                        _ => unreachable!()
+                    })
+                },
+            );
+
+            quote! {
+                fn arbitrary(u: &mut arbitrary::Unstructured<#lifetime>) -> arbitrary::Result<Self> {
+                    #arbitrary
+                }
+
+                fn arbitrary_take_rest(mut u: arbitrary::Unstructured<#lifetime>) -> arbitrary::Result<Self> {
+                    #arbitrary_take_rest
+                }
+            }
+        }
+    };
+    Ok(output)
+}
+
+fn construct(
+    fields: &Fields,
+    ctor: impl Fn(usize, &Field) -> Result<TokenStream>,
+) -> Result<TokenStream> {
+    let output = match fields {
+        Fields::Named(names) => {
+            let names: Vec<TokenStream> = names
+                .named
+                .iter()
+                .enumerate()
+                .map(|(i, f)| {
+                    let name = f.ident.as_ref().unwrap();
+                    ctor(i, f).map(|ctor| quote! { #name: #ctor })
+                })
+                .collect::<Result<_>>()?;
+            quote! { { #(#names,)* } }
+        }
+        Fields::Unnamed(names) => {
+            let names: Vec<TokenStream> = names
+                .unnamed
+                .iter()
+                .enumerate()
+                .map(|(i, f)| ctor(i, f).map(|ctor| quote! { #ctor }))
+                .collect::<Result<_>>()?;
+            quote! { ( #(#names),* ) }
+        }
+        Fields::Unit => quote!(),
+    };
+    Ok(output)
+}
+
+fn construct_take_rest(fields: &Fields) -> Result<TokenStream> {
+    construct(fields, |idx, field| {
+        determine_field_constructor(field).map(|field_constructor| match field_constructor {
+            FieldConstructor::Default => quote!(Default::default()),
+            FieldConstructor::Arbitrary => {
+                if idx + 1 == fields.len() {
+                    quote! { arbitrary::Arbitrary::arbitrary_take_rest(u)? }
+                } else {
+                    quote! { arbitrary::Arbitrary::arbitrary(&mut u)? }
+                }
+            }
+            FieldConstructor::With(function_or_closure) => quote!((#function_or_closure)(&mut u)?),
+            FieldConstructor::Value(value) => quote!(#value),
+        })
+    })
+}
+
+fn gen_size_hint_method(input: &DeriveInput) -> Result<TokenStream> {
+    let size_hint_fields = |fields: &Fields| {
+        fields
+            .iter()
+            .map(|f| {
+                let ty = &f.ty;
+                determine_field_constructor(f).map(|field_constructor| {
+                    match field_constructor {
+                        FieldConstructor::Default | FieldConstructor::Value(_) => {
+                            quote!((0, Some(0)))
+                        }
+                        FieldConstructor::Arbitrary => {
+                            quote! { <#ty as arbitrary::Arbitrary>::size_hint(depth) }
+                        }
+
+                        // Note that in this case it's hard to determine what size_hint must be, so size_of::<T>() is
+                        // just an educated guess, although it's gonna be inaccurate for dynamically
+                        // allocated types (Vec, HashMap, etc.).
+                        FieldConstructor::With(_) => {
+                            quote! { (::core::mem::size_of::<#ty>(), None) }
+                        }
+                    }
+                })
+            })
+            .collect::<Result<Vec<TokenStream>>>()
+            .map(|hints| {
+                quote! {
+                    arbitrary::size_hint::and_all(&[
+                        #( #hints ),*
+                    ])
+                }
+            })
+    };
+    let size_hint_structlike = |fields: &Fields| {
+        size_hint_fields(fields).map(|hint| {
+            quote! {
+                #[inline]
+                fn size_hint(depth: usize) -> (usize, Option<usize>) {
+                    arbitrary::size_hint::recursion_guard(depth, |depth| #hint)
+                }
+            }
+        })
+    };
+    match &input.data {
+        Data::Struct(data) => size_hint_structlike(&data.fields),
+        Data::Union(data) => size_hint_structlike(&Fields::Named(data.fields.clone())),
+        Data::Enum(data) => data
+            .variants
+            .iter()
+            .map(|v| size_hint_fields(&v.fields))
+            .collect::<Result<Vec<TokenStream>>>()
+            .map(|variants| {
+                quote! {
+                    #[inline]
+                    fn size_hint(depth: usize) -> (usize, Option<usize>) {
+                        arbitrary::size_hint::and(
+                            <u32 as arbitrary::Arbitrary>::size_hint(depth),
+                            arbitrary::size_hint::recursion_guard(depth, |depth| {
+                                arbitrary::size_hint::or_all(&[ #( #variants ),* ])
+                            }),
+                        )
+                    }
+                }
+            }),
+    }
+}
+
+fn gen_constructor_for_field(field: &Field) -> Result<TokenStream> {
+    let ctor = match determine_field_constructor(field)? {
+        FieldConstructor::Default => quote!(Default::default()),
+        FieldConstructor::Arbitrary => quote!(arbitrary::Arbitrary::arbitrary(u)?),
+        FieldConstructor::With(function_or_closure) => quote!((#function_or_closure)(u)?),
+        FieldConstructor::Value(value) => quote!(#value),
+    };
+    Ok(ctor)
+}