wip: changes from the past

crates/compiler/src/error.rs

@@ -8,6 +8,8 @@ pub enum Error {
     UndefinedMain,
     #[error(transparent)]
     Mips(#[from] stationeers_mips::error::Error),
+    #[error("internal error during code generation: {0}")]
+    CodeGen(String),
 }
 
 pub type Result<T> = std::result::Result<T, Error>;

crates/compiler/src/lib.rs

@@ -44,13 +44,31 @@ pub fn generate_program(program: ayysee_parser::ast::Program) -> Result<String>
         generate_statement(statement, &mut stack, &mut codegen, Pass::First)?;
     }
 
+    let first_pass_count = codegen.instructions.len();
+    let first_pass = codegen.get_code();
+
     codegen.clear_first_pass();
     stack.clear();
 
     for statement in &program.statements {
         generate_statement(statement, &mut stack, &mut codegen, Pass::Second)?;
     }
 
+    let second_pass_count = codegen.instructions.len();
+    let second_pass = codegen.get_code();
+
+    if first_pass_count != second_pass_count {
+        println!("first pass:");
+        println!("{}", first_pass);
+        println!("second pass:");
+        println!("{}", second_pass);
+
+        return Err(Error::CodeGen(format!(
+            "First pass generated {} instructions, second pass generated {} instructions",
+            first_pass_count, second_pass_count
+        )));
+    }
+
     // ensure the existance of a main function
     if !codegen.has_label("main") {
         return Err(Error::UndefinedMain);

crates/compiler/src/stack.rs

@@ -93,6 +93,7 @@ impl Stack {
 
     /// Clears values between passes.
     pub(crate) fn clear(&mut self) {
+        self.rsp_offset = 0;
         self.loop_counter = 0;
         self.if_counter = 0;
     }

crates/compiler/src/util.rs

@@ -22,7 +22,7 @@ macro_rules! assign_variable {
                 $codegen.add_instruction(Instruction::from(Arithmetic::Add {
                     register: Register::Sp,
                     a: Register::Sp.into(),
-                    b: Number::Int(offset).into(),
+                    b: Number::Int(offset - 1).into(),
                 }));
             }
             Location::Register(register) => {