Merge pull request RustPython#1367 from j30ng/syntax-err-on-star

Return SyntaxError on Invalid Star Expression

Author: coolreader18

bytecode/src/bytecode.rs

@@ -258,7 +258,6 @@ pub enum Instruction {
         before: usize,
         after: usize,
     },
-    Unpack,
     FormatValue {
         conversion: Option<ConversionFlag>,
         spec: String,
@@ -522,7 +521,6 @@ impl Instruction {
             LoadBuildClass => w!(LoadBuildClass),
             UnpackSequence { size } => w!(UnpackSequence, size),
             UnpackEx { before, after } => w!(UnpackEx, before, after),
-            Unpack => w!(Unpack),
             FormatValue { spec, .. } => w!(FormatValue, spec), // TODO: write conversion
             PopException => w!(PopException),
             Reverse { amount } => w!(Reverse, amount),

compiler/src/compile.rs

@@ -1616,10 +1616,13 @@ impl<O: OutputStream> Compiler<O> {
             Comprehension { kind, generators } => {
                 self.compile_comprehension(kind, generators)?;
             }
-            Starred { value } => {
-                self.compile_expression(value)?;
-                self.emit(Instruction::Unpack);
-                panic!("We should not just unpack a starred args, since the size is unknown.");
+            Starred { .. } => {
+                return Err(CompileError {
+                    error: CompileErrorType::SyntaxError(std::string::String::from(
+                        "Invalid starred expression",
+                    )),
+                    location: self.current_source_location.clone(),
+                });
             }
             IfExpression { test, body, orelse } => {
                 let no_label = self.new_label();

vm/src/frame.rs

@@ -478,7 +478,6 @@ impl Frame {
             bytecode::Instruction::UnpackEx { before, after } => {
                 self.execute_unpack_ex(vm, *before, *after)
             }
-            bytecode::Instruction::Unpack => self.execute_unpack(vm),
             bytecode::Instruction::FormatValue { conversion, spec } => {
                 use bytecode::ConversionFlag::*;
                 let value = match conversion {
@@ -979,15 +978,6 @@ impl Frame {
         }
     }
 
-    fn execute_unpack(&self, vm: &VirtualMachine) -> FrameResult {
-        let value = self.pop_value();
-        let elements = vm.extract_elements(&value)?;
-        for element in elements.into_iter().rev() {
-            self.push_value(element);
-        }
-        Ok(None)
-    }
-
     fn jump(&self, label: bytecode::Label) {
         let target_pc = self.code.label_map[&label];
         #[cfg(feature = "vm-tracing-logging")]