replicate clippy lint ptr_offset_with_cast

crates/rpl_meta/src/cli.rs

@@ -37,6 +37,9 @@ pub fn collect_default_patterns() -> Vec<(PathBuf, String)> {
     }
 
     default_patterns!(
+        // When you add a pattern to the list below,
+        // ensure that its order matches the file system's order.
+        // (To ensure consistency of output information during testing)
         // Clippy lints
         "clippy/cast-slice-different-sizes.rpl",
         "clippy/cast-slice-from-raw-parts.rpl",
@@ -45,6 +48,7 @@ pub fn collect_default_patterns() -> Vec<(PathBuf, String)> {
         "clippy/mem-replace-with-uninit.rpl",
         "clippy/mut-from-ref.rpl",
         "clippy/not-unsafe-ptr-arg-deref.rpl",
+        "clippy/ptr-offset-with-cast.rpl",
         "clippy/size-of-in-element-count.rpl",
         "clippy/swap-ptr-to-ref.rpl",
         "clippy/transmute-int-to-non-zero.rpl",

docs/patterns-pest/clippy/ptr-offset-with-cast.rpl

@@ -0,0 +1,35 @@
+pattern ptr-offset-with-cast
+
+patt {
+    #[diag = "ptr-offset-with-cast"]
+    p_offset[
+        $PTR: type where is_ptr(self),
+    ] = fn _ (..) -> _ {
+        let $ptr: $PTR = _;
+        let $offset_usize: usize = _;
+        let $offset_isize: isize = copy $offset_usize as isize (IntToInt);
+        'ptr_offset_call:
+        _ = std::intrinsics::arith_offset::<u8>(copy $ptr, copy $offset_isize);
+    }
+
+    #[diag = "ptr-offset-with-cast"]
+    p_wrapping_offset[
+        $PTR: type where is_ptr(self),
+    ] = fn _ (..) -> _ {
+        let $ptr: $PTR = _;
+        let $offset_usize: usize = _;
+        let $offset_isize: isize = copy $offset_usize as isize (IntToInt);
+        'ptr_offset_call:
+        _ = Offset(copy $ptr, copy $offset_isize);
+    }
+
+}
+
+diag {
+    ptr-offset-with-cast = {
+        primary(ptr_offset_call) = "usage of the `offset` pointer method with a usize casted to an isize.",
+        help = "if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.",
+        name = "ptr_offset_with_cast",
+        level = "warn",
+    }
+}

tests/ui/clippy/ptr_offset_with_cast.rs

@@ -0,0 +1,45 @@
+//@compile-flags: -Z mir-opt-level=0
+fn main() {
+    let vec = vec![b'a', b'b', b'c'];
+    let ptr = vec.as_ptr();
+
+    let offset_u8 = 1_u8;
+    let offset_usize = 1_usize;
+    let offset_isize = 1_isize;
+
+    unsafe {
+        let _ = ptr.offset(offset_usize as isize);
+        //~^ ptr_offset_with_cast
+        //~|ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
+        let _ = ptr.offset(offset_isize as isize);
+        //~^ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
+        let _ = ptr.offset(offset_u8 as isize);
+        //~^ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
+
+        let _ = ptr.wrapping_offset(offset_usize as isize);
+        //~^ ptr_offset_with_cast
+        let _ = ptr.wrapping_offset(offset_isize as isize);
+        let _ = ptr.wrapping_offset(offset_u8 as isize);
+
+        let _ = S.offset(offset_usize as isize);
+        let _ = S.wrapping_offset(offset_usize as isize);
+
+        let _ = (&ptr).offset(offset_usize as isize);
+        //~^ ptr_offset_with_cast
+        //~|ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
+        let _ = (&ptr).wrapping_offset(offset_usize as isize);
+        //~^ ptr_offset_with_cast
+    }
+}
+
+#[derive(Clone, Copy)]
+struct S;
+
+impl S {
+    fn offset(self, _: isize) -> Self {
+        self
+    }
+    fn wrapping_offset(self, _: isize) -> Self {
+        self
+    }
+}

tests/ui/clippy/ptr_offset_with_cast.stderr

@@ -0,0 +1,82 @@
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:19:21
+   |
+LL |         let _ = ptr.wrapping_offset(offset_usize as isize);
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: `-D rpl::ptr-offset-with-cast` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(rpl::ptr_offset_with_cast)]`
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:30:24
+   |
+LL |         let _ = (&ptr).wrapping_offset(offset_usize as isize);
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:11:21
+   |
+LL |         let _ = ptr.offset(offset_usize as isize);
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:27:24
+   |
+LL |         let _ = (&ptr).offset(offset_usize as isize);
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
+error: it is an undefined behavior to offset a pointer using an unchecked integer
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:11:21
+   |
+LL |         let _ = ptr.offset(offset_usize as isize);
+   |                 --- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ offset here
+   |                 |
+   |                 pointer used here
+   |
+   = help: check whether it's in bound before offsetting
+   = note: See the safety section in https://doc.rust-lang.org/std/primitive.pointer.html#method.offset
+   = note: `-D rpl::unchecked-pointer-offset` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(rpl::unchecked_pointer_offset)]`
+
+error: it is an undefined behavior to offset a pointer using an unchecked integer
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:14:21
+   |
+LL |         let _ = ptr.offset(offset_isize as isize);
+   |                 --- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ offset here
+   |                 |
+   |                 pointer used here
+   |
+   = help: check whether it's in bound before offsetting
+   = note: See the safety section in https://doc.rust-lang.org/std/primitive.pointer.html#method.offset
+
+error: it is an undefined behavior to offset a pointer using an unchecked integer
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:16:21
+   |
+LL |         let _ = ptr.offset(offset_u8 as isize);
+   |                 --- ^^^^^^^^^^^^^^^^^^^^^^^^^^ offset here
+   |                 |
+   |                 pointer used here
+   |
+   = help: check whether it's in bound before offsetting
+   = note: See the safety section in https://doc.rust-lang.org/std/primitive.pointer.html#method.offset
+
+error: it is an undefined behavior to offset a pointer using an unchecked integer
+  --> tests/ui/clippy/ptr_offset_with_cast.rs:27:24
+   |
+LL |         let _ = (&ptr).offset(offset_usize as isize);
+   |                 ------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ offset here
+   |                 |
+   |                 pointer used here
+   |
+   = help: check whether it's in bound before offsetting
+   = note: See the safety section in https://doc.rust-lang.org/std/primitive.pointer.html#method.offset
+
+error: aborting due to 8 previous errors
+

tests/ui/clippy/size_of_in_element_count/functions.rs

@@ -73,6 +73,7 @@ fn main() {
 
     unsafe { y.as_ptr().offset(size_of::<u16>() as isize) };
     //~^ size_of_in_element_count
+    //~| ptr_offset_with_cast
 
     y.as_mut_ptr().wrapping_offset(size_of::<u16>() as isize);
     //~^ size_of_in_element_count

tests/ui/clippy/size_of_in_element_count/functions.stderr

@@ -1,3 +1,13 @@
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/clippy/size_of_in_element_count/functions.rs:74:25
+   |
+LL |     unsafe { y.as_ptr().offset(size_of::<u16>() as isize) };
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: `-D rpl::ptr-offset-with-cast` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(rpl::ptr_offset_with_cast)]`
+
 error: found a count of bytes instead of a count of elements of `u16`
   --> tests/ui/clippy/size_of_in_element_count/functions.rs:20:62
    |
@@ -104,7 +114,7 @@ LL |     y.as_mut_ptr().wrapping_add(size_of::<u16>());
    = help: use a count of elements instead of a count of bytes, it already gets multiplied by the size of the type
 
 error: found a count of bytes instead of a count of elements of `u16`
-  --> tests/ui/clippy/size_of_in_element_count/functions.rs:77:36
+  --> tests/ui/clippy/size_of_in_element_count/functions.rs:78:36
    |
 LL |     y.as_mut_ptr().wrapping_offset(size_of::<u16>() as isize);
    |                                    ^^^^^^^^^^^^^^^^
@@ -151,5 +161,5 @@ LL |     unsafe { swap_nonoverlapping(y.as_mut_ptr(), x.as_mut_ptr(), size_of::<
    |
    = help: use a count of elements instead of a count of bytes, it already gets multiplied by the size of the type
 
-error: aborting due to 19 previous errors
+error: aborting due to 20 previous errors
 

tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs

@@ -14,6 +14,9 @@ impl<T> Drop for Slab<T> {
         for x in 0..self.len {
             unsafe {
                 let elem_ptr = self.mem.offset(x as isize);
+                //~^ ptr_offset_with_cast
+                //~| HELP: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+                //~| HELP: to override `-D warnings` add `#[allow(rpl::ptr_offset_with_cast)]`
                 ptr::drop_in_place(elem_ptr);
                 std::hint::black_box(elem_ptr);
             }
@@ -27,8 +30,10 @@ impl<T> Index<usize> for Slab<T> {
     fn index(&self, index: usize) -> &Self::Output {
         unsafe { &(*(self.mem.offset(index as isize))) }
         //~^ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
-        //~|HELP:  check whether it's in bound before offsetting
-        //~|HELP:  to override `-D warnings` add `#[allow(rpl::unchecked_pointer_offset)]`
+        //~| HELP:  check whether it's in bound before offsetting
+        //~| HELP:  to override `-D warnings` add `#[allow(rpl::unchecked_pointer_offset)]`
+        //~| ptr_offset_with_cast
+        //~| HELP: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
     }
 }
 
@@ -49,9 +54,13 @@ impl<T> Slab<T> {
             elem_ptr = self.mem.offset(offset as isize);
             //~^ ERROR: it is an undefined behavior to offset a pointer using an unchecked integer
             //~| HELP: check whether it's in bound before offsetting
+            //~| ptr_offset_with_cast
+            //~| HELP: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
             last_elem_ptr = self.mem.offset(self.len as isize);
             //~^ HELP: this is because `self.len` exceeds the container's length by one
             //~| HELP: did you mean this
+            //~| ptr_offset_with_cast
+            //~| HELP: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
 
             elem = ptr::read(elem_ptr);
             last_elem = ptr::read(last_elem_ptr);

tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.stderr

@@ -1,5 +1,23 @@
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:16:41
+   |
+LL |                 let elem_ptr = self.mem.offset(x as isize);
+   |                                         ^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: `-D rpl::ptr-offset-with-cast` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(rpl::ptr_offset_with_cast)]`
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:31:31
+   |
+LL |         unsafe { &(*(self.mem.offset(index as isize))) }
+   |                               ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
 error: it is an undefined behavior to offset a pointer using an unchecked integer
-  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:28:31
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:31:31
    |
 LL |         unsafe { &(*(self.mem.offset(index as isize))) }
    |                      -------- ^^^^^^^^^^^^^^^^^^^^^^ offset here
@@ -11,8 +29,24 @@ LL |         unsafe { &(*(self.mem.offset(index as isize))) }
    = note: `-D rpl::unchecked-pointer-offset` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(rpl::unchecked_pointer_offset)]`
 
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:54:33
+   |
+LL |             elem_ptr = self.mem.offset(offset as isize);
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:59:38
+   |
+LL |             last_elem_ptr = self.mem.offset(self.len as isize);
+   |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+
 error: it is an undefined behavior to offset a pointer using an unchecked integer
-  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:49:33
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:54:33
    |
 LL |             elem_ptr = self.mem.offset(offset as isize);
    |                        -------- ^^^^^^^^^^^^^^^^^^^^^^^ offset here
@@ -23,7 +57,7 @@ LL |             elem_ptr = self.mem.offset(offset as isize);
    = note: See the safety section in https://doc.rust-lang.org/std/primitive.pointer.html#method.offset
 
 error: pointer out of bound
-  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:57:25
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:66:25
    |
 LL |             last_elem_ptr = self.mem.offset(self.len as isize);
    |                                      -------------------------
@@ -35,14 +69,14 @@ LL |             last_elem = ptr::read(last_elem_ptr);
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^ pointer read here
    |
 help: this is because `self.len` exceeds the container's length by one
-  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:52:45
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:59:45
    |
 LL |             last_elem_ptr = self.mem.offset(self.len as isize);
    |                                             ^^^^^^^^
    = note: `#[deny(rpl::offset_by_one)]` on by default
 
 error: it usually isn't necessary to apply #[inline] to generic functions
-  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:37:5
+  --> tests/ui/cve/cve_2020_35892_3/cve_2020_35892_3.rs:42:5
    |
 LL |       #[inline]
    |       --------- `#[inline]` here
@@ -57,5 +91,5 @@ LL | |     }
    = note: `-D rpl::generic-function-marked-inline` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(rpl::generic_function_marked_inline)]`
 
-error: aborting due to 4 previous errors
+error: aborting due to 8 previous errors
 

tests/ui/cve/cve_2021_25905/minimal.inline.stderr

@@ -0,0 +1,52 @@
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2021_25905/minimal.rs:19:38
+   |
+LL |                     buf.as_mut_ptr().offset(b as isize),
+   |                                      ^^^^^^^^^^^^^^^^^^
+...
+LL |     cases!(Vec::new());
+   |     ------------------ in this macro invocation
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: `-D rpl::ptr-offset-with-cast` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(rpl::ptr_offset_with_cast)]`
+   = note: this error originates in the macro `cases` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2021_25905/minimal.rs:19:38
+   |
+LL |                     buf.as_mut_ptr().offset(b as isize),
+   |                                      ^^^^^^^^^^^^^^^^^^
+...
+LL |     cases!(vec![1, 2, 3]);
+   |     --------------------- in this macro invocation
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: this error originates in the macro `cases` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2021_25905/minimal.rs:19:38
+   |
+LL |                     buf.as_mut_ptr().offset(b as isize),
+   |                                      ^^^^^^^^^^^^^^^^^^
+...
+LL |     cases!(Vec::with_capacity(0));
+   |     ----------------------------- in this macro invocation
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: this error originates in the macro `cases` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: usage of the `offset` pointer method with a usize casted to an isize.
+  --> tests/ui/cve/cve_2021_25905/minimal.rs:19:38
+   |
+LL |                     buf.as_mut_ptr().offset(b as isize),
+   |                                      ^^^^^^^^^^^^^^^^^^
+...
+LL |     cases!(Vec::with_capacity(1));
+   |     ----------------------------- in this macro invocation
+   |
+   = help: if you’re always increasing the pointer address, you can avoid the numeric cast by using the `add` method instead.
+   = note: this error originates in the macro `cases` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 4 previous errors
+