more lowering

analysis/src/ir/pretty.rs

@@ -0,0 +1,163 @@
+use std::fmt::{Display, Formatter, Result, Write};
+
+use super::{BinKind, Branch, ConstValue, Func, Ir, Operand, StatementKind};
+use crate::ir::Register;
+
+pub fn ir_to_string(ir: &Ir) -> String {
+    let mut buf = String::new();
+    PrettyPrinter { out: &mut buf }.ir(ir).unwrap();
+    buf
+}
+
+pub fn func_to_string(func: &Func) -> String {
+    let mut buf = String::new();
+    PrettyPrinter { out: &mut buf }.func(func).unwrap();
+    buf
+}
+
+pub struct PrettyPrinter<W> {
+    out: W,
+}
+
+impl<W: Write> PrettyPrinter<W> {
+    pub fn ir(&mut self, ir: &Ir) -> Result {
+        for (_, func) in &ir.funcs {
+            self.func(func)?;
+        }
+        Ok(())
+    }
+
+    pub fn func(&mut self, func: &Func) -> Result {
+        writeln!(self.out, "def {}() {{", func.name)?;
+
+        let print_reg = |reg: Register| {
+            display_fn(move |f| match func.regs[reg.0 as usize].name {
+                None => write!(f, "%{}", reg.0),
+                Some(name) => write!(f, "%{name}"),
+            })
+        };
+
+        let print_op = |op: Operand| {
+            display_fn(move |f| match op {
+                Operand::Const(c) => Display::fmt(&c, f),
+                Operand::Reg(reg) => Display::fmt(&print_reg(reg), f),
+            })
+        };
+
+        for (i, bb) in func.bbs.iter().enumerate() {
+            if i > 0 {
+                writeln!(self.out)?;
+            }
+            writeln!(self.out, "  {i}:")?;
+
+            for stmt in &bb.statements {
+                match stmt.kind {
+                    StatementKind::Alloca { reg, size, align } => {
+                        writeln!(
+                            self.out,
+                            "    {} = alloca, size={}, align={}",
+                            print_reg(reg),
+                            print_op(size),
+                            print_op(align)
+                        )
+                    }
+                    StatementKind::Store {
+                        ptr_reg,
+                        value,
+                        size,
+                        align,
+                    } => writeln!(
+                        self.out,
+                        "    store {}, {}, size={}, align={}",
+                        print_reg(ptr_reg),
+                        print_op(value),
+                        print_op(size),
+                        print_op(align)
+                    ),
+                    StatementKind::Load {
+                        result,
+                        ptr_reg,
+                        size,
+                        align,
+                    } => writeln!(
+                        self.out,
+                        "    {} = load {}, size={}, align={}",
+                        print_reg(result),
+                        print_reg(ptr_reg),
+                        print_op(size),
+                        print_op(align)
+                    ),
+                    StatementKind::BinOp {
+                        kind,
+                        lhs,
+                        rhs,
+                        result,
+                    } => writeln!(
+                        self.out,
+                        "    {} = {} {}, {}",
+                        print_reg(result),
+                        match kind {
+                            BinKind::Add => "add",
+                            BinKind::Sub => "sub",
+                            BinKind::Mul => "mul",
+                            BinKind::Div => "div",
+                            BinKind::Mod => "mod",
+                            BinKind::Eq => "eq",
+                            BinKind::Neq => "neq",
+                            BinKind::Gt => "gt",
+                            BinKind::Geq => "geq",
+                            BinKind::Lt => "gl",
+                            BinKind::Leq => "leq",
+                        },
+                        print_op(lhs),
+                        print_op(rhs)
+                    ),
+                    StatementKind::PtrOffset {
+                        result,
+                        reg,
+                        amount,
+                    } => writeln!(
+                        self.out,
+                        "    {} = ptroffset {}, {}",
+                        print_reg(result),
+                        print_reg(reg),
+                        print_op(amount)
+                    ),
+                }?;
+            }
+
+            match bb.term {
+                Branch::Goto(bbn) => writeln!(self.out, "    goto {}", bbn)?,
+                Branch::Switch { cond, yes, no } => {
+                    writeln!(self.out, "    switch {}, {yes}, {no}", print_op(cond))?
+                }
+                Branch::Ret(op) => writeln!(self.out, "    ret {}", print_op(op))?,
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl Display for ConstValue {
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+        match self {
+            ConstValue::Int(int) => <_ as Display>::fmt(int, f),
+            ConstValue::Void => f.write_str("void"),
+        }
+    }
+}
+
+fn display_fn<F: Fn(&mut Formatter<'_>) -> Result>(f: F) -> impl Display {
+    struct DisplayFn<F> {
+        f: F,
+    }
+
+    impl<F: Fn(&mut Formatter<'_>) -> Result> Display for DisplayFn<F> {
+        fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+            (self.f)(f)
+        }
+    }
+
+    DisplayFn { f }
+}

analysis/src/lib.rs

@@ -14,7 +14,10 @@ pub struct Error {
 }
 
 impl Error {
-    pub fn new(msg: String, span: Span) -> Self {
-        Self { msg, span }
+    pub fn new(msg: impl Into<String>, span: Span) -> Self {
+        Self {
+            msg: msg.into(),
+            span,
+        }
     }
 }

analysis/src/lower.rs

@@ -1,18 +1,20 @@
 use parser::{
-    ast::{DeclAttr, ExternalDecl, Stmt, TranslationUnit, TypeSpecifier},
+    ast::{self, Atom, DeclAttr, Expr, ExternalDecl, Stmt, TranslationUnit, TypeSpecifier},
     Span, Symbol,
 };
 use rustc_hash::FxHashMap;
 
 use crate::{
     ir::{
-        BasicBlock, Branch, ConstValue, Func, Ir, Layout, Operand, Register, RegisterData,
-        Statement, StatementKind,
+        self, BasicBlock, BinKind, Branch, ConstValue, Func, Ir, Layout, Operand, Register,
+        RegisterData, Statement, StatementKind,
     },
     ty::Ty,
     Error,
 };
 
+type Result<T, E = Error> = std::result::Result<T, E>;
+
 struct LoweringCx {}
 
 pub fn lower_translation_unit(ast: &TranslationUnit) -> Result<Ir, Error> {
@@ -25,7 +27,13 @@ pub fn lower_translation_unit(ast: &TranslationUnit) -> Result<Ir, Error> {
                 let decl = def.decl.uwnrap_normal();
                 let body = &def.body;
                 let ret_ty = lower_ty(&decl.decl_spec.ty);
-                lower_body(&mut lcx, body, decl.init_declarators[0].1, ret_ty)?;
+                lower_body(
+                    &mut lcx,
+                    body,
+                    decl.init_declarators[0].1,
+                    decl.init_declarators[0].0.declarator.decl.name().0,
+                    ret_ty,
+                )?;
             }
         }
     }
@@ -41,10 +49,18 @@ struct FnLoweringCtxt {
 }
 
 impl FnLoweringCtxt {
+    fn resolve_ident(&self, ident: Symbol) -> Option<&VariableInfo> {
+        self.scopes.iter().rev().find_map(|s| s.get(&ident))
+    }
+
+    fn new_reg(&mut self, name: Option<Symbol>) -> Register {
+        let reg = Register(self.ir.regs.len().try_into().unwrap());
+        self.ir.regs.push(RegisterData { name });
+        reg
+    }
+
     fn alloca(&mut self, layout: &Layout, name: Option<Symbol>, span: Span) -> Register {
-        let bb = self.bb_mut();
-        let reg = Register(bb.regs.len().try_into().unwrap());
-        bb.regs.push(RegisterData { name });
+        let reg = self.new_reg(name);
         let stmt = Statement {
             span,
             kind: StatementKind::Alloca {
@@ -53,10 +69,62 @@ impl FnLoweringCtxt {
                 align: Operand::Const(ConstValue::u64(layout.align)),
             },
         };
-        bb.statements.push(stmt);
+        self.bb_mut().statements.push(stmt);
         reg
     }
 
+    fn lower_expr(&mut self, expr: &ast::Expr, span: Span) -> Result<Operand> {
+        match expr {
+            ast::Expr::Atom(Atom::Char(c)) => Ok(Operand::Const(ConstValue::Int((*c).into()))),
+            ast::Expr::Atom(Atom::Int(i)) => Ok(Operand::Const(ConstValue::Int(*i as _))),
+            ast::Expr::Atom(Atom::Float(_)) => todo!("no floats"),
+            ast::Expr::Atom(Atom::Ident(_)) => todo!("no idents"),
+            ast::Expr::Atom(Atom::String(_)) => todo!("no string literals"),
+            ast::Expr::Unary(_) => todo!("no unaries"),
+            ast::Expr::Binary(binary) => {
+                let lhs = self.lower_expr(&binary.lhs.0, binary.lhs.1)?;
+                let rhs = self.lower_expr(&binary.rhs.0, binary.rhs.1)?;
+                let kind = match binary.op {
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Mul) => BinKind::Mul,
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Div) => BinKind::Div,
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Mod) => BinKind::Mod,
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Add) => BinKind::Add,
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Sub) => BinKind::Sub,
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Shl) => todo!("shl"),
+                    ast::BinaryOp::Arith(ast::ArithOpKind::Shr) => todo!("shr"),
+                    ast::BinaryOp::Arith(ast::ArithOpKind::BitAnd) => todo!("&"),
+                    ast::BinaryOp::Arith(ast::ArithOpKind::BitXor) => todo!("^"),
+                    ast::BinaryOp::Arith(ast::ArithOpKind::BitOr) => todo!("|"),
+                    ast::BinaryOp::LogicalAnd => todo!("no logical or"),
+                    ast::BinaryOp::LogicalOr => todo!("no logical and"),
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::Lt) => BinKind::Lt,
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::Gt) => BinKind::Gt,
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::LtEq) => BinKind::Leq,
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::GtEq) => BinKind::Geq,
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::Eq) => BinKind::Eq,
+                    ast::BinaryOp::Comparison(ast::ComparisonKind::Neq) => BinKind::Neq,
+                    ast::BinaryOp::Comma => todo!("no comma"),
+                    ast::BinaryOp::Index => todo!("no index"),
+                    ast::BinaryOp::Assign(_) => todo!("no assign"),
+                };
+
+                let reg = self.new_reg(None);
+                let stmt = StatementKind::BinOp {
+                    kind,
+                    lhs,
+                    rhs,
+                    result: reg,
+                };
+                self.bb_mut()
+                    .statements
+                    .push(Statement { span, kind: stmt });
+
+                Ok(Operand::Reg(reg))
+            }
+            Expr::Postfix(_) => todo!(),
+        }
+    }
+
     fn bb_mut(&mut self) -> &mut BasicBlock {
         &mut self.ir.bbs[self.current_bb as usize]
     }
@@ -76,16 +144,18 @@ fn lower_body(
     _lcx: &mut LoweringCx,
     body: &[(Stmt, Span)],
     def_span: Span,
+    name: Symbol,
     ret_ty: Ty,
 ) -> Result<Func, Error> {
     let mut cx: FnLoweringCtxt = FnLoweringCtxt {
         scopes: vec![FxHashMap::default()],
         ir: Func {
-            bbs: vec![BasicBlock {
             regs: Vec::new(),
+            bbs: vec![BasicBlock {
                 statements: Vec::new(),
                 term: Branch::Goto(0),
             }],
+            name,
             def_span,
             ret_ty,
         },
@@ -134,12 +204,44 @@ fn lower_body(
             Stmt::Continue => todo!(),
             Stmt::Break => todo!(),
             Stmt::Return(_) => todo!(),
-            Stmt::Expr(_) => todo!(),
+            Stmt::Expr(ast::Expr::Binary(ast::ExprBinary {
+                op: ast::BinaryOp::Assign(assign),
+                lhs,
+                rhs,
+            })) => {
+                if assign.is_some() {
+                    todo!("assign operation");
+                }
+                let rhs = cx.lower_expr(&rhs.0, rhs.1)?;
+                let (Expr::Atom(ast::Atom::Ident((ident, ident_span))), _) = **lhs else {
+                    todo!("complex assignments")
+                };
+                let Some(var) = cx.resolve_ident(ident) else {
+                    return Err(Error::new(format!("cannot find variable {ident}"), ident_span));
+                };
+                let stmt = StatementKind::Store {
+                    ptr_reg: var.ptr_to,
+                    value: rhs,
+                    size: Operand::const_u64(var.layout.size),
+                    align: Operand::const_u64(var.layout.align),
+                };
+                cx.bb_mut().statements.push(Statement {
+                    span: *stmt_span,
+                    kind: stmt,
+                });
+            }
+            Stmt::Expr(expr) => {
+                cx.lower_expr(expr, *stmt_span)?;
+            }
         }
     }
 
+    cx.bb_mut().term = Branch::Ret(Operand::Const(ConstValue::Void));
+
     dbg!(&cx);
 
+    println!("{}", ir::func_to_string(&cx.ir));
+
     Ok(cx.ir)
 }
 

parser/src/ast.rs

@@ -3,7 +3,8 @@ use std::fmt::Debug;
 use bitflags::bitflags;
 use dbg_pls::DebugPls;
 
-use crate::{sym::Symbol, Spanned};
+use crate::sym::Symbol;
+pub use crate::Spanned;
 
 pub type Ident = Spanned<Symbol>;
 
@@ -14,7 +15,7 @@ pub type Ident = Spanned<Symbol>;
 #[derive(Debug, DebugPls)]
 pub enum Atom {
     Ident(Ident),
-    Int(i128),
+    Int(u128),
     Float(f64),
     String(String),
     Char(u8),

parser/src/parser.rs

@@ -512,7 +512,6 @@ where
 
             // TODO: recover here
             let stmt = self.statement()?;
-
             stmts.push(stmt);
         };
         Ok((stmts, brace_span.extend(end_span)))

parser/src/sym.rs

@@ -1,4 +1,8 @@
-use std::{cell::RefCell, fmt::Debug, marker::PhantomData};
+use std::{
+    cell::RefCell,
+    fmt::{Debug, Display},
+    marker::PhantomData,
+};
 
 use dbg_pls::DebugPls;
 use lasso::Spur;
@@ -37,3 +41,9 @@ impl DebugPls for Symbol {
         self.as_str(|s| f.debug_ident(s))
     }
 }
+
+impl Display for Symbol {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        INTERNER.with(|i| f.write_str(i.borrow_mut().resolve(&self.spur)))
+    }
+}

parser/src/token.rs

@@ -71,7 +71,7 @@ pub enum Keyword {
 
 #[derive(Debug, Clone, Copy)]
 pub enum Constant {
-    Int(i128),
+    Int(u128),
     Float(f64),
     Char(u8),
     // adding enumerations here makes no sense.