Handle unused lifetime parameters

trailofbits · Mar 29, 2022 · 71389d8 · 71389d8
1 parent d179954
commit 71389d8
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Showing 2 changed files with 41 additions and 9 deletions.
diff --git a/examples/tests/conversion.rs b/examples/tests/conversion.rs
@@ -38,7 +38,7 @@ mod receiver {
 
     impl From<&X> for Y {
         fn from(_: &X) -> Self {
-            Y
+            Self
         }
     }
 
@@ -66,6 +66,36 @@ mod receiver {
     }
 }
 
+mod lifetime {
+    use serde::{Deserialize, Serialize};
+
+    #[derive(Clone)]
+    struct X<'a>(&'a bool);
+
+    #[derive(Clone, Deserialize, Serialize)]
+    struct Y(bool);
+
+    impl<'a> From<X<'a>> for Y {
+        fn from(x: X) -> Self {
+            Self(*x.0)
+        }
+    }
+
+    impl test_fuzz::Into<X<'static>> for Y {
+        fn into(self) -> X<'static> {
+            X(Box::leak(Box::new(self.0)))
+        }
+    }
+
+    #[test_fuzz::test_fuzz(convert = "X<'a>, Y")]
+    fn target<'a>(x: X<'a>) {}
+
+    #[test]
+    fn test() {
+        target(X(&false));
+    }
+}
+
 #[cfg(feature = "__inapplicable_conversion")]
 mod inapplicable_conversion {
     use serde::{Deserialize, Serialize};
@@ -81,7 +111,7 @@ mod inapplicable_conversion {
 
     impl From<Y> for Z {
         fn from(_: Y) -> Self {
-            Z
+            Self
         }
     }
 

diff --git a/macro/src/lib.rs b/macro/src/lib.rs
@@ -19,9 +19,9 @@ use subprocess::{Exec, Redirection};
 use syn::{
     parse::Parser, parse_macro_input, parse_quote, parse_str, punctuated::Punctuated, token,
     Attribute, AttributeArgs, Block, Expr, FnArg, GenericArgument, GenericParam, Generics, Ident,
-    ImplItem, ImplItemMethod, ItemFn, ItemImpl, ItemMod, PatType, Path, PathArguments, PathSegment,
-    Receiver, ReturnType, Signature, Stmt, Type, TypeParam, TypePath, TypeReference, TypeSlice,
-    Visibility, WhereClause, WherePredicate,
+    ImplItem, ImplItemMethod, ItemFn, ItemImpl, ItemMod, LifetimeDef, PatType, Path, PathArguments,
+    PathSegment, Receiver, ReturnType, Signature, Stmt, Type, TypeParam, TypePath, TypeReference,
+    TypeSlice, Visibility, WhereClause, WherePredicate,
 };
 use toolchain_find::find_installed_component;
 use unzip_n::unzip_n;
@@ -1008,12 +1008,14 @@ fn type_generic_phantom_types(generics: &Generics) -> Vec<Type> {
     generics
         .params
         .iter()
-        .filter_map(|param| {
-            if let GenericParam::Type(TypeParam { ident, .. }) = param {
+        .filter_map(|param| match param {
+            GenericParam::Type(TypeParam { ident, .. }) => {
                 Some(parse_quote! { std::marker::PhantomData< #ident > })
-            } else {
-                None
             }
+            GenericParam::Lifetime(LifetimeDef { lifetime, .. }) => {
+                Some(parse_quote! { std::marker::PhantomData< & #lifetime () > })
+            }
+            GenericParam::Const(_) => None,
         })
         .collect()
 }