return FrameKind in FramStack::current_frame by value (#2248)

Author: Robbepop

crates/wasmparser/src/binary_reader.rs

@@ -882,7 +882,7 @@ impl<'a> BinaryReader<'a> {
     }
 
     #[inline]
-    fn expect_frame(&mut self, stack: &impl FrameStack, k: &FrameKind, found: &str) -> Result<()> {
+    fn expect_frame(&mut self, stack: &impl FrameStack, k: FrameKind, found: &str) -> Result<()> {
         if stack.current_frame() == Some(k) {
             return Ok(());
         }
@@ -918,7 +918,7 @@ impl<'a> BinaryReader<'a> {
             0x03 => visitor.visit_loop(self.read_block_type()?),
             0x04 => visitor.visit_if(self.read_block_type()?),
             0x05 => {
-                self.expect_frame(visitor, &FrameKind::If, "else")?;
+                self.expect_frame(visitor, FrameKind::If, "else")?;
                 visitor.visit_else()
             }
             0x06 => {
@@ -937,9 +937,9 @@ impl<'a> BinaryReader<'a> {
                         "legacy_exceptions feature required for catch instruction"
                     );
                 }
-                match self.expect_frame(visitor, &FrameKind::LegacyCatch, "catch") {
+                match self.expect_frame(visitor, FrameKind::LegacyCatch, "catch") {
                     Ok(()) => (),
-                    Err(_) => self.expect_frame(visitor, &FrameKind::LegacyTry, "catch")?,
+                    Err(_) => self.expect_frame(visitor, FrameKind::LegacyTry, "catch")?,
                 }
                 visitor.visit_catch(self.read_var_u32()?)
             }
@@ -962,7 +962,7 @@ impl<'a> BinaryReader<'a> {
             0x14 => visitor.visit_call_ref(self.read()?),
             0x15 => visitor.visit_return_call_ref(self.read()?),
             0x18 => {
-                self.expect_frame(visitor, &FrameKind::LegacyTry, "delegate")?;
+                self.expect_frame(visitor, FrameKind::LegacyTry, "delegate")?;
                 visitor.visit_delegate(self.read_var_u32()?)
             }
             0x19 => {
@@ -972,9 +972,9 @@ impl<'a> BinaryReader<'a> {
                         "legacy_exceptions feature required for catch_all instruction"
                     );
                 }
-                match self.expect_frame(visitor, &FrameKind::LegacyCatch, "catch_all") {
+                match self.expect_frame(visitor, FrameKind::LegacyCatch, "catch_all") {
                     Ok(()) => (),
-                    Err(_) => self.expect_frame(visitor, &FrameKind::LegacyTry, "catch_all")?,
+                    Err(_) => self.expect_frame(visitor, FrameKind::LegacyTry, "catch_all")?,
                 }
                 visitor.visit_catch_all()
             }

crates/wasmparser/src/readers/core/operators.rs

@@ -338,7 +338,7 @@ crate::for_each_operator!(define_operator);
 /// requirements of the binary format.
 pub trait FrameStack {
     /// The current frame kind.
-    fn current_frame(&self) -> Option<&FrameKind>;
+    fn current_frame(&self) -> Option<FrameKind>;
 }
 
 /// Adapters from VisitOperators to FrameStacks
@@ -348,8 +348,8 @@ struct FrameStackAdapter<'a, T> {
 }
 
 impl<T> FrameStack for FrameStackAdapter<'_, T> {
-    fn current_frame(&self) -> Option<&FrameKind> {
-        self.stack.last()
+    fn current_frame(&self) -> Option<FrameKind> {
+        self.stack.last().copied()
     }
 }
 
@@ -359,8 +359,8 @@ struct SingleFrameAdapter<'a, T> {
 }
 
 impl<T> FrameStack for SingleFrameAdapter<'_, T> {
-    fn current_frame(&self) -> Option<&FrameKind> {
-        Some(&self.current_frame)
+    fn current_frame(&self) -> Option<FrameKind> {
+        Some(self.current_frame)
     }
 }
 
@@ -547,8 +547,8 @@ impl<'a> OperatorsReader<'a> {
 }
 
 impl<'a> FrameStack for OperatorsReader<'a> {
-    fn current_frame(&self) -> Option<&FrameKind> {
-        self.stack.last()
+    fn current_frame(&self) -> Option<FrameKind> {
+        self.stack.last().copied()
     }
 }
 
@@ -1051,7 +1051,7 @@ impl<'a> BinaryReader<'a> {
     /// the `Operator`, or if the input is malformed.
     pub fn peek_operator<T: FrameStack>(&self, stack: &T) -> Result<Operator<'a>> {
         self.clone().visit_operator(&mut SingleFrameAdapter {
-            current_frame: *stack.current_frame().ok_or_else(|| {
+            current_frame: stack.current_frame().ok_or_else(|| {
                 format_err!(
                     self.original_position(),
                     "operators remaining after end of function body or expression"

crates/wasmparser/src/validator/core.rs

@@ -468,8 +468,8 @@ impl ModuleState {
         }
 
         impl<'a> FrameStack for VisitConstOperator<'a> {
-            fn current_frame(&self) -> Option<&FrameKind> {
-                Some(&self.ops.get_frame(0)?.kind)
+            fn current_frame(&self) -> Option<FrameKind> {
+                Some(self.ops.get_frame(0)?.kind)
             }
         }
     }

crates/wasmparser/src/validator/operators.rs

@@ -4380,7 +4380,7 @@ impl<R> FrameStack for WasmProposalValidator<'_, '_, R>
 where
     R: WasmModuleResources,
 {
-    fn current_frame(&self) -> Option<&FrameKind> {
-        Some(&self.0.control.last()?.kind)
+    fn current_frame(&self) -> Option<FrameKind> {
+        Some(self.0.control.last()?.kind)
     }
 }