feat(cfg): Support cfg analyse

src/ast/graph.rs

@@ -2,7 +2,7 @@ use petgraph::dot::{Config, Dot};
 use petgraph::graph::{Graph, NodeIndex};
 
 use crate::ast::types::{
-    ArrayDimension, BlockStmt, BreakStmt, CompileUnit, ContinueStmt, Expr, ExprValue, FuncDeclStmt, GlobalDeclStmt, IfStmt, Param, ReturnStmt, Statement, VarDeclStmt, VarDeclStmtValue, WhileStmt
+    ArrayDimension, BlockStmt, BreakStmt, CompileUnit, ContinueStmt, Expr, ExprValue, ForInit, ForStmt, FuncDeclStmt, GlobalDeclStmt, IfStmt, Param, ReturnStmt, Statement, VarDeclStmt, VarDeclStmtValue, WhileStmt
 };
 
 pub type AstGraph = Graph<String, String>;
@@ -77,6 +77,9 @@ impl AstGraphBuilder {
         for dimension in &value.dimensions {
             self.add_array_dimension(node, dimension);
         }
+        if let Some(expr) = &value.value {
+            self.add_expr(node, expr);
+        }
         node
     }
 
@@ -134,6 +137,7 @@ impl AstGraphBuilder {
             },
             Statement::If(if_stmt) => self.add_if_stmt(parent, if_stmt),
             Statement::While(while_stmt) => self.add_while_stmt(parent, while_stmt),
+            Statement::For(for_stmt) => self.add_for_stmt(parent, for_stmt),
             Statement::Break(break_stmt) => self.add_break_stmt(parent, break_stmt),
             Statement::Continue(continue_stmt) => self.add_continue_stmt(parent, continue_stmt),
         }
@@ -160,6 +164,42 @@ impl AstGraphBuilder {
         self.add_block_stmt(node, &while_stmt.body);
         node
     }
+    fn add_for_stmt(&mut self, parent: NodeIndex, for_stmt: &ForStmt) -> NodeIndex {
+        let node = self.child(parent, for_stmt.to_string());
+        match &for_stmt.init {
+            Some(ForInit::Expr(expr)) => {
+                let init = self.child(node, "Init");
+                self.add_expr(init, expr);
+            }
+            Some(ForInit::VarDecl(var_decl)) => {
+                let init = self.child(node, "Init");
+                self.add_var_decl(init, var_decl);
+            }
+            None => {
+                self.child(node, "NoInit");
+            }
+        }
+        match &for_stmt.condition {
+            Some(expr) => {
+                let condition = self.child(node, "Condition");
+                self.add_expr(condition, expr);
+            }
+            None => {
+                self.child(node, "NoCondition");
+            }
+        }
+        match &for_stmt.update {
+            Some(expr) => {
+                let update = self.child(node, "Update");
+                self.add_expr(update, expr);
+            }
+            None => {
+                self.child(node, "NoUpdate");
+            }
+        }
+        self.add_block_stmt(node, &for_stmt.body);
+        node
+    }
     fn add_break_stmt(&mut self, parent: NodeIndex, break_stmt: &BreakStmt) -> NodeIndex {
         self.child(parent, break_stmt.to_string())
     }
@@ -200,6 +240,11 @@ impl AstGraphBuilder {
                 self.add_expr(node, operand);
                 node
             }
+            ExprValue::IncDec { operand, .. } => {
+                let node = self.child(parent, expr.value.to_string());
+                self.add_expr(node, operand);
+                node
+            }
         }
     }
 }

src/ast/mod.rs

@@ -1,2 +1,3 @@
 pub mod graph;
+pub mod parser;
 pub mod types;

src/ast/types.rs

@@ -1,4 +1,4 @@
-use crate::{diagnostic::span::Span, frontend::types::{Token, TokenValue, TypeIdent}};
+use crate::{diagnostic::span::Span, lexer::types::{TokenValue, TypeIdent}};
 use std::fmt;
 
 pub struct CompileUnit {
@@ -18,6 +18,7 @@ pub struct VarDeclStmtValue {
     pub name: String,
     pub name_span: Span,
     pub dimensions: Vec<ArrayDimension>,
+    pub value: Option<Expr>,
 }
 
 pub struct ArrayDimension {
@@ -44,6 +45,7 @@ pub enum Statement {
     VarDecl(VarDeclStmt),
     If(IfStmt),
     While(WhileStmt),
+    For(ForStmt),
     Break(BreakStmt),
     Continue(ContinueStmt),
 }
@@ -77,6 +79,16 @@ pub struct WhileStmt {
     pub body: BlockStmt,
     // pub span: Span,
 }
+pub struct ForStmt {
+    pub init: Option<ForInit>,
+    pub condition: Option<Expr>,
+    pub update: Option<Expr>,
+    pub body: BlockStmt,
+}
+pub enum ForInit {
+    Expr(Expr),
+    VarDecl(VarDeclStmt),
+}
 pub struct BreakStmt {
     pub span: Span,
 }
@@ -107,6 +119,11 @@ pub enum ExprValue {
         op: UnaryOp,
         operand: Box<Expr>,
     },
+    IncDec {
+        op: IncDecOp,
+        operand: Box<Expr>,
+        is_prefix: bool,
+    },
     FuncCall(String, Vec<Expr>),
     Assign {
         lvalue: Box<Expr>, 
@@ -124,6 +141,11 @@ pub enum BinaryOp {
 pub enum UnaryOp {
     Add, Sub, Not,
 }
+#[derive(Clone, Copy)]
+pub enum IncDecOp {
+    Inc,
+    Dec,
+}
 impl BinaryOp {
     pub fn from_token_value(token_value: &TokenValue) -> Option<Self> {
         match token_value {
@@ -227,6 +249,7 @@ impl fmt::Display for Statement {
             Statement::VarDecl(_) => write!(f, "VarDeclStmt"),
             Statement::If(_) => write!(f, "IfStmt"),
             Statement::While(_) => write!(f, "WhileStmt"),
+            Statement::For(_) => write!(f, "ForStmt"),
             Statement::Break(_) => write!(f, "BreakStmt"),
             Statement::Continue(_) => write!(f, "ContinueStmt"),
         }
@@ -249,6 +272,12 @@ impl fmt::Display for WhileStmt {
     }
 }
 
+impl fmt::Display for ForStmt {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "ForStmt")
+    }
+}
+
 impl fmt::Display for BreakStmt {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "BreakStmt")
@@ -277,6 +306,7 @@ impl fmt::Display for ExprValue {
             ExprValue::FuncCall(name, _) => write!(f, "FuncCall({})", name),
             ExprValue::Assign { .. } => write!(f, "Assign"),
             ExprValue::UnaryOp { op, .. } => write!(f, "UnaryOp({})", op),
+            ExprValue::IncDec { op, is_prefix, .. } => write!(f, "{}{}", if *is_prefix { "Prefix" } else { "Postfix" }, op),
         }
     }
 }
@@ -317,6 +347,14 @@ impl fmt::Display for UnaryOp {
         write!(f, "{}", op)
     }
 }
+impl fmt::Display for IncDecOp {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            IncDecOp::Inc => write!(f, "Inc"),
+            IncDecOp::Dec => write!(f, "Dec"),
+        }
+    }
+}
 impl fmt::Display for Type {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {

src/backend/generator.rs

@@ -78,6 +78,23 @@ fn emit_store_stack(src: Register, offset: i32, reg_allocator: &mut RegisterAllo
 fn load_variable(variable: Variable, reg_allocator: &mut RegisterAllocator, var_index_to_stack_offset: &BTreeMap<usize, usize>, instrs: &mut Vec<ARMInstr>) -> RegisterAlloc {
     if variable.data_type.is_array() {
         let var_alloc = reg_allocator.alloc(variable.clone()).expect("Ran out of registers");
+        if variable.data_type.is_array_param() {
+            match variable.var_type {
+                VariableType::ParamTemp(param_index) => {
+                    if param_index < ARG_REGS.len() {
+                        instrs.push(MoveInstr::new_uncond(var_alloc.reg, RegisterOrImm::Reg(ARG_REGS[param_index])));
+                    } else {
+                        let stack_arg_offset = 8 + ((param_index - ARG_REGS.len()) * 4);
+                        instrs.push(LoadInstr::new(var_alloc.reg, REG_FP, Some(RegisterOrImm::Imm(stack_arg_offset as i32))));
+                    }
+                }
+                _ => {
+                    let stack_offset = var_index_to_stack_offset.get(&variable.index).expect("Variable not declared");
+                    emit_load_stack(var_alloc.reg, *stack_offset as i32, reg_allocator, instrs);
+                }
+            }
+            return var_alloc;
+        }
         match variable.var_type {
             VariableType::Global => {
                 instrs.push(LoadPseudoInstr::new(var_alloc.reg, format!("global_var_{}", variable.index)));
@@ -213,7 +230,7 @@ impl Generator {
                 IRInstr::Store(addr, value) => self.emit_store(addr, value, &var_index_to_stack_offset),
                 IRInstr::Declare(variable) => {
                     assert!(!encounter_entry, "Variable declarations must come before entry instruction");
-                    let size = variable.data_type.size_in_bytes();
+                    let size = if variable.data_type.is_array_param() { 4 } else { variable.data_type.size_in_bytes() };
                     stack_size_needed = (stack_size_needed + size).next_multiple_of(ARM_STACK_ALIGNMENT);
                     var_index_to_stack_offset.insert(variable.index, stack_size_needed);
                 },

src/backend/mod.rs

@@ -10,8 +10,8 @@ mod tests {
     use std::path::Path;
     use std::fs::File;
     use std::io::Write;
-    use crate::frontend::lexer::Lexer;
+    use crate::ast::parser::Parser;
-    use crate::frontend::parser::Parser;
+    use crate::lexer::lexer::Lexer;
     use crate::utils::case_list::CaseList;
     use crate::utils::num_sequence::NumberSequence;
     use crate::ir::generator::Generator as IRGenerator;

src/diagnostic/mod.rs

@@ -1,4 +1,4 @@
-use crate::{diagnostic::span::Span, err::CompileError, frontend::err::FrontendError, ir::err::IRError};
+use crate::{diagnostic::span::Span, err::CompileError, ir::err::IRError, lexer::err::FrontendError};
 
 pub mod span;
 

src/err.rs

@@ -1,6 +1,6 @@
 use thiserror::Error;
 
-use crate::{frontend::err::FrontendError, sema::err::SemaError};
+use crate::{lexer::err::FrontendError, sema::err::SemaError};
 
 #[derive(Debug, Clone, PartialEq, Eq, Error)]
 pub enum CompileError {

src/ir/cfg.rs

@@ -0,0 +1,446 @@
+use std::collections::{BTreeMap, BTreeSet, HashSet};
+
+use petgraph::dot::Dot;
+use petgraph::graph::Graph;
+
+use crate::ir::types::IRInstr;
+
+pub type CfgGraph = Graph<String, String>;
+
+#[derive(Clone)]
+pub struct BasicBlock {
+    pub id: usize,
+    pub instrs: Vec<IRInstr>,
+}
+
+pub struct ControlFlowGraph {
+    pub func_name: String,
+    pub blocks: Vec<BasicBlock>,
+    pub edges: Vec<(usize, usize, String)>,
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum EdgeKind {
+    Branch,
+    Fallthrough,
+}
+
+impl ControlFlowGraph {
+    pub fn from_body(func_name: impl Into<String>, body: &[IRInstr]) -> Self {
+        let blocks = split_basic_blocks(body);
+        let edges = collect_edges(&blocks)
+            .into_iter()
+            .map(|(from, to, label, _)| (from, to, label))
+            .collect();
+        Self {
+            func_name: func_name.into(),
+            blocks,
+            edges,
+        }
+    }
+
+    fn add_to_graph(&self, graph: &mut CfgGraph) {
+        let mut nodes = Vec::new();
+        for block in &self.blocks {
+            nodes.push(graph.add_node(block_dot_label(&self.func_name, block)));
+        }
+        for (from, to, label) in &self.edges {
+            if let (Some(from), Some(to)) = (nodes.get(*from), nodes.get(*to)) {
+                graph.add_edge(*from, *to, label.clone());
+            }
+        }
+    }
+
+    fn refresh_edges(&mut self) {
+        self.edges = collect_edges(&self.blocks)
+            .into_iter()
+            .map(|(from, to, label, _)| (from, to, label))
+            .collect();
+    }
+
+    fn remove_unreachable(&mut self) -> bool {
+        if self.blocks.is_empty() {
+            return false;
+        }
+
+        let edges = collect_edges(&self.blocks);
+        let mut adjacency = vec![Vec::new(); self.blocks.len()];
+        for (from, to, _, _) in edges {
+            adjacency[from].push(to);
+        }
+
+        let mut reachable = vec![false; self.blocks.len()];
+        let mut stack = vec![0];
+        while let Some(index) = stack.pop() {
+            if reachable[index] {
+                continue;
+            }
+            reachable[index] = true;
+            for next in &adjacency[index] {
+                stack.push(*next);
+            }
+        }
+
+        let old_len = self.blocks.len();
+        self.blocks = self
+            .blocks
+            .drain(..)
+            .enumerate()
+            .filter_map(|(index, block)| reachable[index].then_some(block))
+            .collect();
+        let changed = self.blocks.len() != old_len;
+        if changed {
+            self.refresh_edges();
+        }
+        changed
+    }
+
+    fn remove_trivial_blocks(&mut self) -> bool {
+        if self.blocks.is_empty() {
+            return false;
+        }
+
+        let edges = collect_edges(&self.blocks);
+        let explicit_pred_count = explicit_predecessor_counts(self.blocks.len(), &edges);
+        let mut redirect = BTreeMap::new();
+        let mut remove = HashSet::new();
+        let mut fallthrough_gotos = Vec::new();
+
+        for (index, block) in self.blocks.iter().enumerate() {
+            if let Some((label, target)) = jump_only_block(block) {
+                let target = resolve_label(target, &redirect);
+                redirect.insert(label, target);
+                for (from, to, _, kind) in &edges {
+                    if *to == index && *kind == EdgeKind::Fallthrough {
+                        fallthrough_gotos.push((*from, target));
+                    }
+                }
+                remove.insert(index);
+                continue;
+            }
+
+            if let Some(label) = label_only_block(block) {
+                if let Some(next_index) = next_kept_index(index, self.blocks.len(), &remove) {
+                    if let Some(next_label) = first_label(&self.blocks[next_index]) {
+                        redirect.insert(label, resolve_label(next_label, &redirect));
+                        remove.insert(index);
+                    } else if explicit_pred_count[index] == 0 {
+                        remove.insert(index);
+                    }
+                } else if explicit_pred_count[index] == 0 {
+                    remove.insert(index);
+                }
+            }
+        }
+
+        if redirect.is_empty() && remove.is_empty() && fallthrough_gotos.is_empty() {
+            return false;
+        }
+
+        for (from, target) in fallthrough_gotos {
+            if !remove.contains(&from) && !ends_with_terminal(&self.blocks[from]) {
+                self.blocks[from].instrs.push(IRInstr::Goto(target));
+            }
+        }
+
+        for block in &mut self.blocks {
+            rewrite_targets(&mut block.instrs, &redirect);
+        }
+
+        self.blocks = self
+            .blocks
+            .drain(..)
+            .enumerate()
+            .filter_map(|(index, block)| (!remove.contains(&index)).then_some(block))
+            .collect();
+        self.refresh_edges();
+        true
+    }
+
+    fn merge_linear_blocks(&mut self) -> bool {
+        let edges = collect_edges(&self.blocks);
+        let pred_count = predecessor_counts(self.blocks.len(), &edges);
+
+        let mut index = 0;
+        while index + 1 < self.blocks.len() {
+            let successors = edges
+                .iter()
+                .filter_map(|(from, to, _, _)| (*from == index).then_some(*to))
+                .collect::<BTreeSet<_>>();
+
+            if successors.len() == 1 {
+                let successor = *successors.iter().next().unwrap();
+                if successor == index + 1 && pred_count[successor] == 1 {
+                    if matches!(self.blocks[index].instrs.last(), Some(IRInstr::Goto(_))) {
+                        self.blocks[index].instrs.pop();
+                    }
+                    let successor_block = self.blocks.remove(successor);
+                    self.blocks[index].instrs.extend(successor_block.instrs);
+                    self.refresh_edges();
+                    return true;
+                }
+            }
+            index += 1;
+        }
+
+        false
+    }
+
+    fn into_instrs(self) -> Vec<IRInstr> {
+        self.blocks
+            .into_iter()
+            .flat_map(|block| block.instrs)
+            .collect()
+    }
+}
+
+pub fn optimize_ir(ir: Vec<IRInstr>) -> Vec<IRInstr> {
+    ir.into_iter()
+        .map(|instr| match instr {
+            IRInstr::DefineFunc(func, args, body) => {
+                let func_name = func.name.clone();
+                IRInstr::DefineFunc(func, args, optimize_body(&func_name, body))
+            }
+            other => other,
+        })
+        .collect()
+}
+
+pub fn ir_to_cfg_dot(ir: &[IRInstr]) -> String {
+    let mut graph = Graph::new();
+    for instr in ir {
+        if let IRInstr::DefineFunc(func, _, body) = instr {
+            ControlFlowGraph::from_body(func.name.clone(), body).add_to_graph(&mut graph);
+        }
+    }
+    format!("{}", Dot::new(&graph))
+}
+
+pub fn optimize_body(func_name: &str, body: Vec<IRInstr>) -> Vec<IRInstr> {
+    let (mut prologue, cfg_body) = split_function_prologue(body);
+    if cfg_body.is_empty() {
+        return prologue;
+    }
+
+    let mut cfg = ControlFlowGraph::from_body(func_name, &cfg_body);
+    cfg.remove_unreachable();
+    loop {
+        let mut changed = false;
+        changed |= cfg.remove_trivial_blocks();
+        changed |= cfg.remove_unreachable();
+        changed |= cfg.merge_linear_blocks();
+        if !changed {
+            break;
+        }
+    }
+
+    let mut body = cfg.into_instrs();
+    remove_redundant_fallthrough_gotos(&mut body);
+    remove_unused_labels(&mut body);
+    prologue.extend(body);
+    prologue
+}
+
+fn split_function_prologue(mut body: Vec<IRInstr>) -> (Vec<IRInstr>, Vec<IRInstr>) {
+    if let Some(entry_index) = body.iter().position(|instr| matches!(instr, IRInstr::Entry)) {
+        let cfg_body = body.split_off(entry_index + 1);
+        (body, cfg_body)
+    } else {
+        (Vec::new(), body)
+    }
+}
+
+fn split_basic_blocks(instrs: &[IRInstr]) -> Vec<BasicBlock> {
+    if instrs.is_empty() {
+        return Vec::new();
+    }
+
+    let mut leaders = BTreeSet::new();
+    leaders.insert(0);
+    for (index, instr) in instrs.iter().enumerate() {
+        if matches!(instr, IRInstr::Label(_)) {
+            leaders.insert(index);
+        }
+        if is_terminal(instr) && index + 1 < instrs.len() {
+            leaders.insert(index + 1);
+        }
+    }
+
+    let leader_list = leaders.into_iter().collect::<Vec<_>>();
+    let mut blocks = Vec::new();
+    for (block_id, start) in leader_list.iter().enumerate() {
+        let end = leader_list
+            .get(block_id + 1)
+            .copied()
+            .unwrap_or(instrs.len());
+        blocks.push(BasicBlock {
+            id: block_id,
+            instrs: instrs[*start..end].to_vec(),
+        });
+    }
+    blocks
+}
+
+fn collect_edges(blocks: &[BasicBlock]) -> Vec<(usize, usize, String, EdgeKind)> {
+    let label_to_block = label_to_block(blocks);
+    let mut edges = Vec::new();
+
+    for (index, block) in blocks.iter().enumerate() {
+        match block.instrs.last() {
+            Some(IRInstr::Goto(label)) => {
+                if let Some(target) = label_to_block.get(label) {
+                    edges.push((index, *target, "br".to_string(), EdgeKind::Branch));
+                }
+            }
+            Some(IRInstr::CondGoto(_, true_label, false_label)) => {
+                if let Some(target) = label_to_block.get(true_label) {
+                    edges.push((index, *target, "true".to_string(), EdgeKind::Branch));
+                }
+                if let Some(target) = label_to_block.get(false_label) {
+                    edges.push((index, *target, "false".to_string(), EdgeKind::Branch));
+                }
+            }
+            Some(IRInstr::Exit(_)) => {}
+            Some(_) | None => {
+                if index + 1 < blocks.len() {
+                    edges.push((index, index + 1, "fallthrough".to_string(), EdgeKind::Fallthrough));
+                }
+            }
+        }
+    }
+
+    edges
+}
+
+fn label_to_block(blocks: &[BasicBlock]) -> BTreeMap<usize, usize> {
+    let mut map = BTreeMap::new();
+    for (index, block) in blocks.iter().enumerate() {
+        for instr in &block.instrs {
+            if let IRInstr::Label(label) = instr {
+                map.insert(*label, index);
+            }
+        }
+    }
+    map
+}
+
+fn predecessor_counts(block_count: usize, edges: &[(usize, usize, String, EdgeKind)]) -> Vec<usize> {
+    let mut counts = vec![0; block_count];
+    for (_, to, _, _) in edges {
+        counts[*to] += 1;
+    }
+    counts
+}
+
+fn explicit_predecessor_counts(block_count: usize, edges: &[(usize, usize, String, EdgeKind)]) -> Vec<usize> {
+    let mut counts = vec![0; block_count];
+    for (_, to, _, kind) in edges {
+        if *kind == EdgeKind::Branch {
+            counts[*to] += 1;
+        }
+    }
+    counts
+}
+
+fn next_kept_index(index: usize, block_count: usize, remove: &HashSet<usize>) -> Option<usize> {
+    (index + 1..block_count).find(|candidate| !remove.contains(candidate))
+}
+
+fn first_label(block: &BasicBlock) -> Option<usize> {
+    match block.instrs.first() {
+        Some(IRInstr::Label(label)) => Some(*label),
+        _ => None,
+    }
+}
+
+fn label_only_block(block: &BasicBlock) -> Option<usize> {
+    match block.instrs.as_slice() {
+        [IRInstr::Label(label)] => Some(*label),
+        _ => None,
+    }
+}
+
+fn jump_only_block(block: &BasicBlock) -> Option<(usize, usize)> {
+    match block.instrs.as_slice() {
+        [IRInstr::Label(label), IRInstr::Goto(target)] => Some((*label, *target)),
+        _ => None,
+    }
+}
+
+fn is_terminal(instr: &IRInstr) -> bool {
+    matches!(instr, IRInstr::Goto(_) | IRInstr::CondGoto(_, _, _) | IRInstr::Exit(_))
+}
+
+fn ends_with_terminal(block: &BasicBlock) -> bool {
+    block.instrs.last().is_some_and(is_terminal)
+}
+
+fn rewrite_targets(instrs: &mut [IRInstr], redirect: &BTreeMap<usize, usize>) {
+    for instr in instrs {
+        match instr {
+            IRInstr::Goto(label) => *label = resolve_label(*label, redirect),
+            IRInstr::CondGoto(_, true_label, false_label) => {
+                *true_label = resolve_label(*true_label, redirect);
+                *false_label = resolve_label(*false_label, redirect);
+            }
+            _ => {}
+        }
+    }
+}
+
+fn resolve_label(label: usize, redirect: &BTreeMap<usize, usize>) -> usize {
+    let mut current = label;
+    let mut visited = HashSet::new();
+    while let Some(next) = redirect.get(&current) {
+        if !visited.insert(current) {
+            break;
+        }
+        current = *next;
+    }
+    current
+}
+
+fn remove_unused_labels(instrs: &mut Vec<IRInstr>) {
+    let mut used = BTreeSet::new();
+    for instr in instrs.iter() {
+        match instr {
+            IRInstr::Goto(label) => {
+                used.insert(*label);
+            }
+            IRInstr::CondGoto(_, true_label, false_label) => {
+                used.insert(*true_label);
+                used.insert(*false_label);
+            }
+            _ => {}
+        }
+    }
+    instrs.retain(|instr| match instr {
+        IRInstr::Label(label) => used.contains(label),
+        _ => true,
+    });
+}
+
+fn remove_redundant_fallthrough_gotos(instrs: &mut Vec<IRInstr>) {
+    let mut index = 0;
+    while index + 1 < instrs.len() {
+        let remove = match (&instrs[index], &instrs[index + 1]) {
+            (IRInstr::Goto(target), IRInstr::Label(label)) => target == label,
+            _ => false,
+        };
+        if remove {
+            instrs.remove(index);
+        } else {
+            index += 1;
+        }
+    }
+}
+
+fn block_dot_label(func_name: &str, block: &BasicBlock) -> String {
+    let instrs = block
+        .instrs
+        .iter()
+        .map(|instr| instr.to_string())
+        .collect::<Vec<_>>()
+        .join("\\l");
+    format!("{}::B{}\\l{}\\l", func_name, block.id, instrs)
+}

src/ir/generator.rs

@@ -1,6 +1,6 @@
 use std::{collections::BTreeMap, vec};
 
-use crate::{ir::types::{CmpOp, Function, IRInstr, IRType, MoveRValue, UnaryOp, Variable, VariableOrIntLit, VariableType}, sema::{analyzer::Analyzer as SemaAnalyzer, hir::{HirBlockStmt, HirBreakStmt, HirCompileUnit, HirContinueStmt, HirExpr, HirExprValue, HirFuncDeclStmt, HirGlobalDeclStmt, HirIfElseBranch, HirIfStmt, HirReturnStmt, HirStatement, HirVarDeclStmt, HirWhileStmt}, symbol::{FunctionId, SymbolId}}};
+use crate::{ir::types::{BinaryOp as IRBinaryOp, CmpOp, Function, IRInstr, IRType, MoveRValue, UnaryOp, Variable, VariableOrIntLit, VariableType}, sema::{analyzer::Analyzer as SemaAnalyzer, hir::{HirBlockStmt, HirBreakStmt, HirCompileUnit, HirContinueStmt, HirExpr, HirExprValue, HirForInit, HirForStmt, HirFuncDeclStmt, HirGlobalDeclStmt, HirIfElseBranch, HirIfStmt, HirReturnStmt, HirStatement, HirVarDeclStmt, HirWhileStmt}, symbol::{FunctionId, SymbolId}}};
 use crate::ast::types::BinaryOp as AstBinaryOp;
 use crate::ast::types::UnaryOp as AstUnaryOp;
 pub struct Generator<'a> {
@@ -64,11 +64,24 @@ impl<'a> Generator<'a> {
 
     fn generate_var_decl(&mut self, var_decl: HirVarDeclStmt, is_global: bool) -> Vec<IRInstr> {
         let mut instrs = vec![];
-        let var_type = if is_global { VariableType::Global } else { VariableType::Local };
         for value in var_decl.values {
+            let var_type = if is_global { VariableType::Global } else { VariableType::Local };
             let var = self.var_manager.declare_symbol(value.symbol, var_type, self.sema.get_symbol_type(value.symbol).into());
             if is_global {
                 instrs.push(IRInstr::Declare(var));
+            } else if let Some(init) = value.value {
+                self.current_exit_label.push(None);
+                let (init_instrs, init_var) = match self.generate_expr(init) {
+                    Some(res) => res,
+                    None => {
+                        self.current_exit_label.pop();
+                        continue;
+                    }
+                };
+                self.current_exit_label.pop();
+                let target = self.var_manager.get_symbol(value.symbol).unwrap();
+                instrs.extend(init_instrs);
+                instrs.push(IRInstr::Move(target, MoveRValue::Var(init_var.unwrap())));
             }
         }
 
@@ -125,6 +138,7 @@ impl<'a> Generator<'a> {
             Return(return_stmt) => self.generate_return_stmt(return_stmt),
             If(if_stmt) => self.generate_if_stmt(if_stmt),
             While(while_stmt) => self.generate_while_stmt(while_stmt),
+            For(for_stmt) => self.generate_for_stmt(for_stmt),
             Break(break_stmt) => self.generate_break_stmt(break_stmt),
             Continue(continue_stmt) => self.generate_continue_stmt(continue_stmt),
             Block(block_stmt) => {
@@ -193,6 +207,69 @@ impl<'a> Generator<'a> {
         instrs.push(IRInstr::Label(exit_label));
         instrs
     }
+    fn generate_for_stmt(&mut self, for_stmt: HirForStmt) -> Vec<IRInstr> {
+        let mut instrs = vec![];
+        let cond_label = self.request_label();
+        let body_label = self.request_label();
+        let update_label = self.request_label();
+        let exit_label = self.request_label();
+
+        if let Some(init) = for_stmt.init {
+            match init {
+                HirForInit::Expr(init) => {
+                    self.current_exit_label.push(None);
+                    let (init_instrs, _) = match self.generate_expr(init) {
+                        Some(res) => res,
+                        None => {
+                            self.current_exit_label.pop();
+                            return vec![];
+                        }
+                    };
+                    self.current_exit_label.pop();
+                    instrs.extend(init_instrs);
+                }
+                HirForInit::VarDecl(var_decl) => {
+                    instrs.extend(self.generate_var_decl(var_decl, false));
+                }
+            }
+        }
+
+        instrs.push(IRInstr::Label(cond_label));
+        if let Some(condition) = for_stmt.condition {
+            self.current_exit_label.push(Some((body_label, exit_label)));
+            let (cond_instrs, _) = match self.generate_expr(condition) {
+                Some(res) => res,
+                None => {
+                    self.current_exit_label.pop();
+                    return vec![];
+                }
+            };
+            self.current_exit_label.pop();
+            instrs.extend(cond_instrs);
+        }
+
+        instrs.push(IRInstr::Label(body_label));
+        self.while_exit_label.push((update_label, exit_label));
+        instrs.extend(self.generate_block_stmt(for_stmt.body));
+        self.while_exit_label.pop();
+
+        instrs.push(IRInstr::Label(update_label));
+        if let Some(update) = for_stmt.update {
+            self.current_exit_label.push(None);
+            let (update_instrs, _) = match self.generate_expr(update) {
+                Some(res) => res,
+                None => {
+                    self.current_exit_label.pop();
+                    return vec![];
+                }
+            };
+            self.current_exit_label.pop();
+            instrs.extend(update_instrs);
+        }
+        instrs.push(IRInstr::Goto(cond_label));
+        instrs.push(IRInstr::Label(exit_label));
+        instrs
+    }
     fn generate_if_stmt(&mut self, if_stmt: HirIfStmt) -> Vec<IRInstr> {
         let mut instrs = vec![];
         let then_label = self.request_label();
@@ -274,9 +351,13 @@ impl<'a> Generator<'a> {
             HirExprValue::Var(symbol) => {
                 let var = self.var_manager.get_symbol(symbol).unwrap();
                 if var.data_type.is_array() {
+                    if var.data_type.is_array_param() {
+                        (vec![], Some(var))
+                    } else {
                         let ptr_ty = var.data_type.decay_to_ptr().unwrap();
                         let dest = self.var_manager.declare_temp(ptr_ty);
                         (vec![IRInstr::Move(dest.clone(), MoveRValue::Var(var))], Some(dest))
+                    }
                 } else {
                     (vec![], Some(var))
                 }
@@ -372,6 +453,35 @@ impl<'a> Generator<'a> {
                 };
                 (instrs, Some(dest_var))
             },
+            HirExprValue::IncDec { op, operand, is_prefix } => {
+                let result_ty: IRType = expr.ty.clone().into();
+                let (mut instrs, target, is_addr) = self.generate_lvalue(*operand)?;
+                let old_var = self.var_manager.declare_temp(result_ty.clone());
+                if is_addr {
+                    instrs.push(IRInstr::Load(old_var.clone(), target.clone()));
+                } else {
+                    instrs.push(IRInstr::Move(old_var.clone(), MoveRValue::Var(target.clone())));
+                }
+
+                let one = self.var_manager.declare_temp(result_ty.clone());
+                instrs.push(IRInstr::Move(one.clone(), MoveRValue::ConstInt(1)));
+                let new_var = self.var_manager.declare_temp(result_ty.clone());
+                let ir_op = match op {
+                    crate::ast::types::IncDecOp::Inc => IRBinaryOp::Add,
+                    crate::ast::types::IncDecOp::Dec => IRBinaryOp::Sub,
+                };
+                instrs.push(IRInstr::Binary(new_var.clone(), old_var.clone(), ir_op, one));
+                if is_addr {
+                    instrs.push(IRInstr::Store(target, new_var.clone()));
+                } else {
+                    instrs.push(IRInstr::Move(target, MoveRValue::Var(new_var.clone())));
+                }
+                if is_prefix {
+                    (instrs, Some(new_var))
+                } else {
+                    (instrs, Some(old_var))
+                }
+            },
             HirExprValue::BinaryOp { lhs, op, rhs } => {
                 // +--------+-------------------------+-------------------------+-------------------------+
                 // | parent | (true_exit, false_exit) | (true_exit, false_exit) | (true_exit, false_exit) |
@@ -564,8 +674,12 @@ impl<'a> Generator<'a> {
             HirExprValue::Var(symbol) => {
                 let var = self.var_manager.get_symbol(symbol).unwrap();
                 if var.data_type.is_array() {
+                    if var.data_type.is_array_param() {
+                        (vec![], var)
+                    } else {
                         let ptr = self.var_manager.declare_temp(var.data_type.decay_to_ptr().unwrap());
                         (vec![IRInstr::Move(ptr.clone(), MoveRValue::Var(var))], ptr)
+                    }
                 } else {
                     (vec![], var)
                 }
@@ -663,8 +777,8 @@ mod tests {
     use std::fs::File;
     use crate::ast::graph::AstGraphExt;
     use std::io::Write;
-    use crate::frontend::lexer::Lexer;
+    use crate::ast::parser::Parser;
-    use crate::frontend::parser::Parser;
+    use crate::lexer::lexer::Lexer;
     use crate::sema::analyzer::Analyzer;
     use crate::utils::case_list::CaseList;
     use crate::utils::num_sequence::NumberSequence;

src/ir/mod.rs

@@ -1,3 +1,4 @@
 pub mod generator;
 pub mod types;
 pub mod err;
+pub mod cfg;

src/ir/types.rs

@@ -4,6 +4,7 @@ use crate::ast::types::Type as AstType;
 use crate::ast::types::BinaryOp as AstBinaryOp;
 use crate::ir::err::IRError;
 
+#[derive(Clone)]
 pub enum VariableOrIntLit {
     Var(Variable),
     IntLit(i32),
@@ -17,6 +18,7 @@ impl Display for VariableOrIntLit {
         }
     }
 }
+#[derive(Clone)]
 pub enum IRInstr {
     Declare(Variable),
     DefineFunc(Function, Vec<Variable>, Vec<IRInstr>),
@@ -86,6 +88,10 @@ impl IRType {
         matches!(self, IRType::Array(_, _))
     }
 
+    pub fn is_array_param(&self) -> bool {
+        matches!(self, IRType::Array(_, dims) if dims.first().is_some_and(|dim| *dim == 0))
+    }
+
     pub fn decay_to_ptr(&self) -> Option<IRType> {
         match self {
             IRType::Array(elem, dims) => {
@@ -165,6 +171,7 @@ impl From<AstType> for IRType {
         }
     }
 }
+#[derive(Clone)]
 pub enum MoveRValue {
     Var(Variable),
     ConstInt(i32),
@@ -236,6 +243,18 @@ impl Variable {
             _ => format!("{} {}", self.data_type, self),
         }
     }
+
+    pub fn to_typed_string_with_type(&self, ty: &IRType) -> String {
+        match ty {
+            IRType::Array(_, _) => {
+                let (base_type, dims) = ty.base_type_and_dims();
+                let dims_str = dims.iter().map(|dim| format!("[{}]", dim)).collect::<Vec<_>>().join("");
+                format!("{} {}{}", base_type, self, dims_str)
+            }
+            IRType::Ptr(_) => format!("{}* {}", ty.scalar_base_type(), self),
+            _ => format!("{} {}", ty, self),
+        }
+    }
 }
 #[derive(Debug, Clone)]
 pub struct Function {
@@ -247,7 +266,7 @@ pub struct Function {
 impl Function {
     pub fn to_call_string(&self, args: &Vec<Variable>) -> String {
         assert!(args.len() == self.parameter_types.len());
-        let args_str = args.iter().zip(self.parameter_types.iter()).map(|(arg, param)| format!("{} {}", param, arg)).collect::<Vec<_>>().join(", ");
+        let args_str = args.iter().zip(self.parameter_types.iter()).map(|(arg, param)| arg.to_typed_string_with_type(param)).collect::<Vec<_>>().join(", ");
         format!("{} @{}({})", self.return_type, self.name, args_str)
     }
 
@@ -260,6 +279,7 @@ impl Function {
         format!("{} @{}({})", self.return_type, self.name, params_str)
     }
 }
+#[derive(Clone)]
 pub enum BinaryOp {
     Add,
     Sub,
@@ -267,6 +287,7 @@ pub enum BinaryOp {
     Div,
     Mod,
 }
+#[derive(Clone)]
 pub enum CmpOp {
     Le,
     Lt,
@@ -275,6 +296,7 @@ pub enum CmpOp {
     Ne,
     Eq,
 }
+#[derive(Clone)]
 pub enum UnaryOp {
     Neg
 }

src/lexer/err.rs

@@ -1,6 +1,6 @@
 use thiserror::Error;
 
-use crate::frontend::types::{Token, TokenValue};
+use crate::lexer::types::TokenValue;
 
 // #[derive(Debug, Clone, PartialEq, Eq, Error)]
 // pub enum ParseError {

src/lexer/lexer.rs

@@ -1,9 +1,8 @@
-use std::{io::BufRead, str::FromStr};
+use std::str::FromStr;
 
-use codespan_reporting::diagnostic;
 use thiserror::Error;
 
-use crate::{diagnostic::{Diagnositics, span::{self, Span}}, frontend::{err::LexingError, types::{TokenValue, TypeIdent}}};
+use crate::{diagnostic::{Diagnositics, span::Span}, lexer::{err::LexingError, types::{TokenValue, TypeIdent}}};
 
 use super::types::Token;
 
@@ -346,6 +345,9 @@ fn parse_ident(
     if name.eq("while") {
         return Ok(TokenValue::While);
     }
+    if name.eq("for") {
+        return Ok(TokenValue::For);
+    }
     if name.eq("break") {
         return Ok(TokenValue::Break);
     }
@@ -359,6 +361,7 @@ fn parse_ident(
 }
 #[cfg(test)]
 mod tests {
+    use std::io::BufRead;
     use std::path::Path;
     use std::fs::File;
     use crate::utils::case_list::CaseList;

src/lexer/mod.rs

@@ -1,4 +1,3 @@
-pub mod types;
-pub mod lexer;
-pub mod parser;
 pub mod err;
+pub mod lexer;
+pub mod types;

src/lexer/types.rs

@@ -24,9 +24,9 @@ pub enum TokenValue {
     LBracket, RBracket,
     Comma, Semicolon,
 
-    If, Else, While, Return, Break, Continue,
+    If, Else, While, For, Return, Break, Continue,
 
-    // Eof,
+    Eof,
     Unrecognized,
 }
 impl TokenValue {
@@ -77,10 +77,11 @@ impl std::fmt::Display for TokenValue {
             TokenValue::If => write!(f, "if"),
             TokenValue::Else => write!(f, "else"),
             TokenValue::While => write!(f, "while"),
+            TokenValue::For => write!(f, "for"),
             TokenValue::Return => write!(f, "return"),
             TokenValue::Break => write!(f, "break"),
             TokenValue::Continue => write!(f, "continue"),
-            // TokenValue::Eof => write!(f, "<EOF>"),
+            TokenValue::Eof => write!(f, "<EOF>"),
             TokenValue::Unrecognized => write!(f, "unrecognized"),
         }
     }
@@ -100,9 +101,9 @@ pub enum TokenKind {
     LBracket, RBracket,
     Comma, Semicolon,
 
-    If, Else, While, Return, Break, Continue,
+    If, Else, While, For, Return, Break, Continue,
 
-    // Eof,
+    Eof,
     Unrecognized,
 }
 #[derive(Debug, Clone, Copy, PartialEq, Eq, EnumString, AsRefStr)]

src/main.rs

@@ -1,4 +1,4 @@
-mod frontend;
+mod lexer;
 mod ast;
 mod ir;
 mod backend;
@@ -11,7 +11,7 @@ use std::{fs::File, io::BufRead};
 
 use clap::Parser as ArgParser;
 
-use crate::{frontend::{lexer::Lexer, parser::Parser}, ir::generator::Generator, sema::analyzer::Analyzer};
+use crate::{ast::parser::Parser, ir::{cfg, generator::Generator}, lexer::lexer::Lexer, sema::analyzer::Analyzer};
 use crate::backend::generator::Generator as ASMGerenerator;
 /// Simple minic compiler built by Rust
 #[derive(ArgParser, Debug)]
@@ -33,6 +33,9 @@ struct Args {
     /// Output file for the generated code (default: stdout)
     #[arg(short = 'o', long = "output")]
     output: Option<String>,
+    /// Output CFG graph in Graphviz dot format
+    #[arg(long = "cfg-dot")]
+    cfg_dot: Option<String>,
     /// Source file to compile
     source: String,
 }
@@ -85,7 +88,13 @@ fn main() {
         analyzer.get_diagnostics().print(&format!("{}", source_path.display()), &full_text);
     }
     let mut generator = Generator::new(&analyzer);
-    let ir = generator.emit(hir);
+    let ir = cfg::optimize_ir(generator.emit(hir));
+    if let Some(cfg_dot_path) = &args.cfg_dot {
+        match std::fs::write(cfg_dot_path, cfg::ir_to_cfg_dot(&ir)) {
+            Ok(_) => println!("CFG graph written to {}", cfg_dot_path),
+            Err(e) => eprintln!("Failed to write CFG graph to {}: {}", cfg_dot_path, e),
+        }
+    }
     if args.output_ir {
         if let Some(output_path) = args.output {
             match std::fs::write(&output_path, ir.iter().map(|instr| instr.to_string()).collect::<Vec<_>>().join("\n")) {

src/sema/analyzer.rs

@@ -2,7 +2,7 @@ use std::collections::BTreeMap;
 
 use crate::{
     ast::types::{
-        ArrayDimension, BinaryOp, BlockStmt, BreakStmt, CompileUnit, ContinueStmt, Expr, ExprValue, FuncDeclStmt,
+        ArrayDimension, BinaryOp, BlockStmt, BreakStmt, CompileUnit, ContinueStmt, Expr, ExprValue, ForInit, ForStmt, FuncDeclStmt,
         GlobalDeclStmt, IfElseBranch, IfStmt, ReturnStmt, Statement, VarDeclStmt, WhileStmt,
     },
     diagnostic::{span::Span, Diagnositics},
@@ -10,7 +10,7 @@ use crate::{
         err::SemaError,
         hir::{
             HirBlockStmt, HirBreakStmt, HirCompileUnit, HirContinueStmt, HirExpr, HirExprValue,
-            HirFuncDeclStmt, HirGlobalDeclStmt, HirIfElseBranch, HirIfStmt, HirParam,
+            HirForInit, HirForStmt, HirFuncDeclStmt, HirGlobalDeclStmt, HirIfElseBranch, HirIfStmt, HirParam,
             HirReturnStmt, HirStatement, HirVarDeclStmt, HirVarDeclStmtValue, HirWhileStmt,
         },
         symbol::{FunctionId, FunctionSig, SymbolId, SymbolKind, SymbolTable},
@@ -39,7 +39,9 @@ impl Analyzer {
         };
         analyzer.declare_builtin_func("putint", vec![SemaType::I32], SemaType::Void);
         analyzer.declare_builtin_func("putch", vec![SemaType::I32], SemaType::Void);
+        analyzer.declare_builtin_func("putarray", vec![SemaType::I32, SemaType::Array(Box::new(SemaType::I32), vec![0])], SemaType::Void);
         analyzer.declare_builtin_func("getint", vec![], SemaType::I32);
+        analyzer.declare_builtin_func("getarray", vec![SemaType::Array(Box::new(SemaType::I32), vec![0])], SemaType::I32);
         analyzer
     }
 
@@ -102,10 +104,24 @@ impl Analyzer {
         for value in var_decl.values {
             let data_type = self.build_var_type(base_type.clone(), &value.dimensions, false);
             match self.symbols.declare_variable(&value.name, kind, data_type) {
-                Ok(symbol) => values.push(HirVarDeclStmtValue {
+                Ok(symbol) => {
+                    let symbol_type = self.symbols.get_symbol(symbol).ty.clone();
+                    let init = value.value.and_then(|expr| {
+                        let span = expr.span;
+                        let init = self.analyze_expr(expr)?;
+                        if init.ty == SemaType::Void {
+                            self.add_error(SemaError::InvalidOperand(SemaType::Void), span);
+                        } else if !self.type_matches(&symbol_type, &init.ty) {
+                            self.add_error(SemaError::TypeMismatch(symbol_type.clone(), init.ty.clone()), span);
+                        }
+                        Some(init)
+                    });
+                    values.push(HirVarDeclStmtValue {
                         symbol,
                         name_span: value.name_span,
-                }),
+                        value: init,
+                    });
+                }
                 Err(e) => self.add_error(e, value.name_span),
             }
         }
@@ -185,20 +201,11 @@ impl Analyzer {
                         self.add_error(SemaError::InvalidArrayDimension, dimension.span);
                     }
                 }
-                None if is_param && i == 0 => {}
+                None if is_param && i == 0 => dims.push(0),
                 None => self.add_error(SemaError::InvalidArrayDimension, dimension.span),
             }
         }
-        if is_param {
-            let pointee_type = if dims.is_empty() {
-                base_type
-            } else {
         SemaType::Array(Box::new(base_type), dims)
-            };
-            SemaType::Ptr(Box::new(pointee_type))
-        } else {
-            SemaType::Array(Box::new(base_type), dims)
-        }
     }
 
     fn analyze_block_stmt(&mut self, block_stmt: BlockStmt) -> HirBlockStmt {
@@ -216,6 +223,7 @@ impl Analyzer {
             Statement::Return(stmt) => Some(HirStatement::Return(self.analyze_return_stmt(stmt))),
             Statement::If(stmt) => Some(HirStatement::If(self.analyze_if_stmt(stmt))),
             Statement::While(stmt) => Some(HirStatement::While(self.analyze_while_stmt(stmt))),
+            Statement::For(stmt) => Some(HirStatement::For(self.analyze_for_stmt(stmt))),
             Statement::Break(stmt) => Some(HirStatement::Break(self.analyze_break_stmt(stmt))),
             Statement::Continue(stmt) => Some(HirStatement::Continue(self.analyze_continue_stmt(stmt))),
             Statement::Block(stmt) => {
@@ -294,6 +302,26 @@ impl Analyzer {
         }
     }
 
+    fn analyze_for_stmt(&mut self, for_stmt: ForStmt) -> HirForStmt {
+        self.symbols.enter_scope();
+        let init = for_stmt.init.and_then(|init| match init {
+            ForInit::Expr(expr) => self.analyze_expr(expr).map(HirForInit::Expr),
+            ForInit::VarDecl(var_decl) => Some(HirForInit::VarDecl(self.analyze_var_decl(var_decl, SymbolKind::Local))),
+        });
+        let condition = for_stmt.condition.map(|expr| self.analyze_condition_expr(expr));
+        let update = for_stmt.update.and_then(|expr| self.analyze_expr(expr));
+        self.loop_depth += 1;
+        let body = self.analyze_block_stmt(for_stmt.body);
+        self.loop_depth -= 1;
+        self.symbols.exit_scope();
+        HirForStmt {
+            init,
+            condition,
+            update,
+            body,
+        }
+    }
+
     fn analyze_break_stmt(&mut self, stmt: BreakStmt) -> HirBreakStmt {
         if self.loop_depth == 0 {
             self.add_error(SemaError::BreakOutsideLoop, stmt.span);
@@ -369,6 +397,27 @@ impl Analyzer {
                     span,
                 })
             }
+            ExprValue::IncDec { op, operand, is_prefix } => {
+                if !matches!(operand.value, ExprValue::Var(_) | ExprValue::ArrayAccess { .. }) {
+                    self.add_error(SemaError::InvalidAssignmentTarget, operand.span);
+                    return None;
+                }
+                let operand_span = operand.span;
+                let operand = self.analyze_expr(*operand)?;
+                if !operand.ty.is_scalar() {
+                    self.add_error(SemaError::InvalidOperand(operand.ty.clone()), operand_span);
+                    return None;
+                }
+                Some(HirExpr {
+                    ty: operand.ty.clone(),
+                    value: HirExprValue::IncDec {
+                        op,
+                        operand: Box::new(operand),
+                        is_prefix,
+                    },
+                    span,
+                })
+            }
             ExprValue::BinaryOp { lhs, op, rhs } => self.analyze_binary_expr(*lhs, op, *rhs, span),
             ExprValue::FuncCall(func_name, args) => self.analyze_func_call_expr(func_name, args, span),
         }
@@ -524,6 +573,11 @@ impl Analyzer {
         if expected == actual {
             return true;
         }
+        if let (SemaType::Array(expected_elem, expected_dims), SemaType::Array(actual_elem, actual_dims)) = (expected, actual) {
+            return expected_elem == actual_elem
+                && expected_dims.len() == actual_dims.len()
+                && expected_dims.iter().zip(actual_dims.iter()).all(|(expected_dim, actual_dim)| *expected_dim == 0 || expected_dim == actual_dim);
+        }
         matches!((expected, actual), (SemaType::Ptr(expected_elem), SemaType::Array(_, _)) if actual.indexed_type().is_some_and(|ty| &ty == expected_elem.as_ref()))
     }
 }

src/sema/hir.rs

@@ -18,6 +18,7 @@ pub struct HirVarDeclStmt {
 pub struct HirVarDeclStmtValue {
     pub symbol: SymbolId,
     pub name_span: Span,
+    pub value: Option<HirExpr>,
 }
 
 pub struct HirFuncDeclStmt {
@@ -46,6 +47,7 @@ pub enum HirStatement {
     VarDecl(HirVarDeclStmt),
     If(HirIfStmt),
     While(HirWhileStmt),
+    For(HirForStmt),
     Break(HirBreakStmt),
     Continue(HirContinueStmt),
 }
@@ -67,6 +69,18 @@ pub struct HirWhileStmt {
     pub body: HirBlockStmt,
 }
 
+pub struct HirForStmt {
+    pub init: Option<HirForInit>,
+    pub condition: Option<HirExpr>,
+    pub update: Option<HirExpr>,
+    pub body: HirBlockStmt,
+}
+
+pub enum HirForInit {
+    Expr(HirExpr),
+    VarDecl(HirVarDeclStmt),
+}
+
 pub struct HirBreakStmt {
     pub span: Span,
 }
@@ -102,6 +116,11 @@ pub enum HirExprValue {
         op: UnaryOp,
         operand: Box<HirExpr>,
     },
+    IncDec {
+        op: crate::ast::types::IncDecOp,
+        operand: Box<HirExpr>,
+        is_prefix: bool,
+    },
     FuncCall(FunctionId, Vec<HirExpr>),
     Assign {
         lvalue: Box<HirExpr>,

src/sema/types.rs

@@ -35,6 +35,8 @@ impl SemaType {
             SemaType::Array(elem, dims) => {
                 if dims.len() == 1 {
                     Some((**elem).clone())
+                } else if dims.first().is_some_and(|dim| *dim == 0) {
+                    Some(SemaType::Array(elem.clone(), dims[1..].to_vec()))
                 } else {
                     Some(SemaType::Array(elem.clone(), dims[1..].to_vec()))
                 }