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use proc_macro2::TokenStream;
use quote::{quote, quote_spanned};
use crate::utils::*;
use syn::spanned::Spanned;
use syn::{Data, Ident};
use std::str::FromStr;
pub(crate) fn get_post_mutation_impl(ident: &Ident, data: &Data) -> TokenStream {
match *data {
Data::Struct(ref data) => {
if let syn::Fields::Named(ref fields) = data.fields {
let fields = parse_fields(&fields);
if fields.is_empty() {
return TokenStream::new();
}
let mut base_tokens = quote_spanned! { ident.span() => };
for field in fields {
let field_name = &field.field.ident;
let field_ty = &field.field.ty;
base_tokens.extend(quote_spanned! { field.field.span() =>
<#field_ty>::fixup(&mut self.#field_name, mutator);
});
}
return base_tokens;
} else {
panic!("struct contains unnamed fields");
}
}
_ => TokenStream::new(),
}
}
pub(crate) fn get_post_fuzzer_iteration_impls(ident: &Ident, data: &Data) -> TokenStream {
match *data {
Data::Struct(ref data) => {
if let syn::Fields::Named(ref fields) = data.fields {
let fields = parse_fields(&fields);
if fields.is_empty() {
return TokenStream::new();
}
let mut base_tokens = quote_spanned!(ident.span() => );
for field in fields {
let field_name = field.field.ident;
let field_type = &field.field.ty;
base_tokens.extend(quote_spanned! { field.field.span() =>
<#field_type>::on_success(&self.#field_name);
});
}
return base_tokens;
} else {
panic!("struct contains unnamed fields");
}
}
_ => TokenStream::new(),
}
}
pub(crate) fn gen_mutate_impl(ident: &Ident, data: &Data) -> TokenStream {
let mutate_body: TokenStream;
match *data {
Data::Enum(ref data) => {
let enum_ident = ident.to_string();
let mut enum_has_non_unit_variants = false;
let mut mutate_match_arms: Vec<TokenStream> = Vec::new();
for variant in &data.variants {
let variant_ident = TokenStream::from_str(&format!(
"{}::{}",
enum_ident,
variant.ident.to_string()
))
.unwrap();
match variant.fields {
syn::Fields::Unnamed(ref fields) => {
let mut parameters = TokenStream::new();
let mut mutate_call = TokenStream::new();
for (i, ref unnamed) in fields.unnamed.iter().enumerate() {
let field_ty = &unnamed.ty;
let ident = TokenStream::from_str(&format!("field_{}", i)).unwrap();
mutate_call.extend(quote_spanned! { unnamed.span() =>
let constraints = max_size.and_then(|max|{
let mut c = ::lain::types::Constraints::new();
c.base_object_size_accounted_for = true;
c.max_size(max);
Some(c)
});
<#field_ty>::m(#ident, mutator, constraints.as_ref());
if <#field_ty>::is_variable_size() {
max_size = max_size.map(|max| {
// in case a user didn't appropriately supply a max size constraint (i.e. a max
// size that's smaller than the object's min size), we don't want to panic
let serialized_size = #ident.serialized_size();
if serialized_size > max {
warn!("Max size provided to object is likely smaller than min object size");
0
} else {
max - serialized_size
}
});
}
});
parameters.extend(quote_spanned! {unnamed.span() => ref mut #ident,});
}
mutate_match_arms.push(quote! {
#variant_ident(#parameters) => {
#mutate_call
},
});
enum_has_non_unit_variants = true;
}
syn::Fields::Unit => {
break;
}
_ => panic!("unsupported enum variant type"),
}
}
mutate_body = if !enum_has_non_unit_variants {
// TODO: This will keep any #[fuzzer(ignore)] or #[weight(N)] attributes...
// which we probably don't want.
quote_spanned! { ident.span() =>
*self = <#ident>::new_fuzzed(mutator, parent_constraints);
}
} else {
quote_spanned! { ident.span() =>
// Make a copy of the constraints that will remain immutable for
// this function. Here we ensure that the base size of this object has
// been accounted for by the caller, which may be an object containing this.
let parent_constraints = parent_constraints.and_then(|c| {
let mut c = c.clone();
c.account_for_base_object_size::<Self>();
Some(c)
});
let mut max_size = parent_constraints.as_ref().and_then(|c| c.max_size);
match *self {
#(#mutate_match_arms)*
}
}
};
}
Data::Struct(ref data) => {
if let syn::Fields::Named(ref fields) = data.fields {
let fields = parse_fields(&fields);
mutate_body = gen_struct_mutate_impl(&fields);
} else {
panic!("struct contains unnamed fields");
}
}
Data::Union(ref _data) => {
panic!("unions are unsupported. Please use an enum with typed variants instead");
}
}
quote_spanned! { ident.span() =>
#[allow(unused)]
fn mutate<R: ::lain::rand::Rng>(&mut self, mutator: &mut ::lain::mutator::Mutator<R>, parent_constraints: Option<&::lain::types::Constraints<u8>>) {
#mutate_body
if mutator.should_fixup() {
self.fixup(mutator);
}
}
}
}
fn gen_struct_mutate_impl(fields: &[FuzzerObjectStructField]) -> TokenStream {
let mutation_parts: Vec<TokenStream> = fields
.iter()
.map(|f| {
let mut field_mutation_tokens = TokenStream::new();
let span = f.field.span();
let ty = &f.field.ty;
let ident = &f.field.ident;
let ident_str = ident.as_ref().unwrap().to_string();
let weighted = &f.weighted;
let default_constraints = if f.min.is_some() || f.max.is_some() {
let min = f
.min
.as_ref()
.map(|v| quote! {Some(#v)})
.unwrap_or_else(|| quote! {None});
let max = f
.max
.as_ref()
.map(|v| quote! {Some(#v)})
.unwrap_or_else(|| quote! {None});
quote_spanned! { span =>
let mut constraints = Constraints::new();
constraints.min = #min;
constraints.max = #max;
constraints.max_size = max_size.clone();
constraints.weighted = #weighted;
constraints.base_object_size_accounted_for = true;
let constraints = Some(constraints);
}
} else {
quote_spanned! { span =>
let constraints = max_size.and_then(|max|{
let mut c = ::lain::types::Constraints::new();
c.base_object_size_accounted_for = true;
c.max_size(max);
Some(c)
});
}
};
field_mutation_tokens.extend(quote! {
#default_constraints
<#ty>::mutate(&mut self.#ident, mutator, constraints.as_ref());
if <#ty>::is_variable_size() {
max_size = max_size.map(|max| {
// in case a user didn't appropriately supply a max size constraint (i.e. a max
// size that's smaller than the object's min size), we don't want to panic
let serialized_size = self.#ident.serialized_size();
if serialized_size > max {
warn!("Max size provided to object is likely smaller than min object size");
0
} else {
max - serialized_size
}
});
}
if mutator.should_early_bail_mutation() {
if mutator.should_fixup() {
<#ty>::fixup(&mut self.#ident, mutator);
}
return;
}
});
field_mutation_tokens
})
.collect();
quote! {
// Make a copy of the constraints that will remain immutable for
// this function. Here we ensure that the base size of this object has
// been accounted for by the caller, which may be an object containing this.
let parent_constraints = parent_constraints.and_then(|c| {
let mut c = c.clone();
c.account_for_base_object_size::<Self>();
Some(c)
});
let mut max_size = parent_constraints.as_ref().and_then(|c| c.max_size);
#(#mutation_parts)*
}
}