Add ui test for missing_transmute_annotations

Author: GuillaumeGomez

tests/ui/auxiliary/macro_rules.rs

@@ -50,3 +50,10 @@ macro_rules! macro_with_panic {
         panic!()
     };
 }
+
+#[macro_export]
+macro_rules! bad_transmute {
+    ($e:expr) => {
+        std::mem::transmute($e)
+    };
+}

tests/ui/missing_transmute_annotations.fixed

@@ -0,0 +1,64 @@
+//@aux-build:macro_rules.rs
+
+#![warn(clippy::missing_transmute_annotations)]
+
+#[macro_use]
+extern crate macro_rules;
+
+macro_rules! local_bad_transmute {
+    ($e:expr) => {
+        std::mem::transmute::<[u16; 2], i32>($e)
+    };
+}
+
+fn bar(x: i32) -> i32 {
+    x
+}
+
+unsafe fn foo1() -> i32 {
+    std::mem::transmute::<[u16; 2], i32>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo2() -> i32 {
+    std::mem::transmute::<[u16; 2], i32>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo3() -> i32 {
+    std::mem::transmute::<[u16; 2], i32>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo4() -> i32 {
+    std::mem::transmute::<[u16; 2], i32>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo5() -> i32 {
+    let x: i32 = bar(std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]));
+    //~^ ERROR: transmute used without annotations
+    bar(std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]))
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo6() -> i32 {
+    local_bad_transmute!([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo7() -> i32 {
+    // Should not warn.
+    bad_transmute!([1u16, 2u16])
+}
+
+fn main() {
+    unsafe {
+        // Should not warn.
+        std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]);
+        let x = std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute::<[u16; 2], _>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute::<_, i32>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute([1u16, 2u16]);
+    }
+}

tests/ui/missing_transmute_annotations.rs

@@ -0,0 +1,64 @@
+//@aux-build:macro_rules.rs
+
+#![warn(clippy::missing_transmute_annotations)]
+
+#[macro_use]
+extern crate macro_rules;
+
+macro_rules! local_bad_transmute {
+    ($e:expr) => {
+        std::mem::transmute($e)
+    };
+}
+
+fn bar(x: i32) -> i32 {
+    x
+}
+
+unsafe fn foo1() -> i32 {
+    std::mem::transmute([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo2() -> i32 {
+    std::mem::transmute::<_, _>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo3() -> i32 {
+    std::mem::transmute::<_, i32>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo4() -> i32 {
+    std::mem::transmute::<[u16; 2], _>([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo5() -> i32 {
+    let x: i32 = bar(std::mem::transmute::<[u16; 2], _>([1u16, 2u16]));
+    //~^ ERROR: transmute used without annotations
+    bar(std::mem::transmute::<[u16; 2], _>([1u16, 2u16]))
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo6() -> i32 {
+    local_bad_transmute!([1u16, 2u16])
+    //~^ ERROR: transmute used without annotations
+}
+
+unsafe fn foo7() -> i32 {
+    // Should not warn.
+    bad_transmute!([1u16, 2u16])
+}
+
+fn main() {
+    unsafe {
+        // Should not warn.
+        std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]);
+        let x = std::mem::transmute::<[u16; 2], i32>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute::<[u16; 2], _>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute::<_, i32>([1u16, 2u16]);
+        let x: i32 = std::mem::transmute([1u16, 2u16]);
+    }
+}

tests/ui/missing_transmute_annotations.stderr

@@ -0,0 +1,52 @@
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:19:15
+   |
+LL |     std::mem::transmute([1u16, 2u16])
+   |               ^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+   |
+   = note: `-D clippy::missing-transmute-annotations` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::missing_transmute_annotations)]`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:24:15
+   |
+LL |     std::mem::transmute::<_, _>([1u16, 2u16])
+   |               ^^^^^^^^^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:29:15
+   |
+LL |     std::mem::transmute::<_, i32>([1u16, 2u16])
+   |               ^^^^^^^^^^^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:34:15
+   |
+LL |     std::mem::transmute::<[u16; 2], _>([1u16, 2u16])
+   |               ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:39:32
+   |
+LL |     let x: i32 = bar(std::mem::transmute::<[u16; 2], _>([1u16, 2u16]));
+   |                                ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:41:19
+   |
+LL |     bar(std::mem::transmute::<[u16; 2], _>([1u16, 2u16]))
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+
+error: transmute used without annotations
+  --> tests/ui/missing_transmute_annotations.rs:10:19
+   |
+LL |         std::mem::transmute($e)
+   |                   ^^^^^^^^^ help: consider adding missing annotations: `transmute::<[u16; 2], i32>`
+...
+LL |     local_bad_transmute!([1u16, 2u16])
+   |     ---------------------------------- in this macro invocation
+   |
+   = note: this error originates in the macro `local_bad_transmute` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 7 previous errors
+