param

analysis/src/ir.rs

@@ -69,6 +69,8 @@ pub struct Func<'cx> {
     pub name: Symbol,
     pub def_span: Span,
     pub ret_ty: Ty<'cx>,
+    /// The amount of function parameters. regs[..arity] are the parameters.
+    pub arity: u32,
 }
 
 #[derive(Clone, Copy)]

analysis/src/ir/pretty.rs

@@ -28,8 +28,6 @@ impl<W: Write> PrettyPrinter<W> {
     }
 
     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),
@@ -37,6 +35,16 @@ impl<W: Write> PrettyPrinter<W> {
             })
         };
 
+        write!(self.out, "def {}(", func.name)?;
+        for param in 0..func.arity {
+            let reg = &func.regs[param as usize];
+            write!(self.out, "{} {}", reg.tyl.ty, print_reg(Register(param)))?;
+            if (param + 1) != func.arity {
+                write!(self.out, ", ")?;
+            }
+        }
+        writeln!(self.out, ") {{",)?;
+
         let print_op = |op: Operand| {
             display_fn(move |f| match op {
                 Operand::Const(c) => Display::fmt(&c, f),

analysis/src/lower.rs

@@ -4,7 +4,8 @@ use std::cell::{Cell, RefCell};
 
 use parser::{
     ast::{
-        self, Atom, DeclAttr, Expr, ExprBinary, ExternalDecl, Stmt, TranslationUnit, TypeSpecifier,
+        self, Atom, DeclAttr, Expr, ExprBinary, ExternalDecl, InitDecl, Stmt, TranslationUnit,
+        TypeSpecifier,
     },
     Span, Symbol,
 };
@@ -120,16 +121,17 @@ pub fn lower_translation_unit<'cx>(
         match decl {
             ExternalDecl::Decl(_) => todo!("decl is unsupported"),
             ExternalDecl::FunctionDef(def) => {
-                let decl = def.decl.uwnrap_normal();
+                let decl = def.decl.unwrap_normal();
                 let body = &def.body;
                 let ret_ty = lcx.lower_ty(&decl.decl_spec.ty);
-                let func = lower_body(
-                    &lcx,
-                    body,
-                    decl.init_declarators[0].1,
-                    decl.init_declarators[0].0.declarator.decl.name().0,
-                    ret_ty,
-                )?;
+
+                let (ref declarator, def_span) = decl.init_declarators[0];
+
+                let ast::DirectDeclarator::WithParams { ident, params } = &declarator.declarator.decl else {
+                    unreachable!("function def needs withparams declarator");
+                };
+
+                let func = lower_func(&lcx, body, def_span, ident.0, ret_ty, params)?;
                 ir.funcs.insert(lcx.next_def_id(), func);
             }
         }
@@ -161,37 +163,42 @@ impl<'a, 'cx> FnLoweringCtxt<'a, 'cx> {
         Ok(())
     }
 
+    fn declare_local(&mut self, decl: &ast::Decl, span: Span) -> Result<()> {
+        let decl = decl.unwrap_normal();
+        let ty = self.lcx.lower_ty(&decl.decl_spec.ty);
+        let decl_attr = decl.decl_spec.attrs;
+
+        for (var, def_span) in &decl.init_declarators {
+            let tyl = self.lcx.layout_of(ty);
+            let (name, name_span) = var.declarator.decl.name();
+            let ptr_to = self.build.alloca(tyl.layout, Some(name), span);
+
+            let variable_info = VariableInfo {
+                def_span: *def_span,
+                ptr_to,
+                decl_attr,
+                tyl: tyl.clone(),
+            };
+            let predeclared = self.scopes.last_mut().unwrap().insert(name, variable_info);
+            if let Some(predeclared) = predeclared {
+                return Err(Error::new(
+                    format!("variable {name} has already been declared"),
+                    name_span,
+                )
+                .note_spanned("already declared here", predeclared.def_span));
+            }
+            if let Some((init, init_span)) = &var.init {
+                let init = self.lower_expr(init, *init_span)?;
+                self.build.store(ptr_to, init, tyl.layout, *init_span);
+            }
+        }
+        Ok(())
+    }
+
     fn lower_stmt(&mut self, stmt: &ast::Stmt, stmt_span: Span) -> Result<()> {
         match stmt {
             Stmt::Decl(decl) => {
-                let decl = decl.uwnrap_normal();
-                let ty = self.lcx.lower_ty(&decl.decl_spec.ty);
-                let decl_attr = decl.decl_spec.attrs;
-
-                for (var, def_span) in &decl.init_declarators {
-                    let tyl = self.lcx.layout_of(ty);
-                    let (name, name_span) = var.declarator.decl.name();
-                    let ptr_to = self.build.alloca(tyl.layout, Some(name), stmt_span);
-
-                    let variable_info = VariableInfo {
-                        def_span: *def_span,
-                        ptr_to,
-                        decl_attr,
-                        tyl: tyl.clone(),
-                    };
-                    let predeclared = self.scopes.last_mut().unwrap().insert(name, variable_info);
-                    if let Some(predeclared) = predeclared {
-                        return Err(Error::new(
-                            format!("variable {name} has already been declared"),
-                            name_span,
-                        )
-                        .note_spanned("already declared here", predeclared.def_span));
-                    }
-                    if let Some((init, init_span)) = &var.init {
-                        let init = self.lower_expr(init, *init_span)?;
-                        self.build.store(ptr_to, init, tyl.layout, *init_span);
-                    }
-                }
+                self.declare_local(decl, stmt_span)?;
             }
             Stmt::Labeled { .. } => todo!("labels are not implemented"),
             Stmt::Compound(block) => {
@@ -393,20 +400,68 @@ struct VariableInfo<'cx> {
     decl_attr: DeclAttr,
 }
 
-fn lower_body<'cx>(
+fn lower_func<'cx>(
     // may be used later
     lcx: &LoweringCx<'cx>,
     body: &[(Stmt, Span)],
     def_span: Span,
     name: Symbol,
     ret_ty: Ty<'cx>,
+    params: &[ast::FunctionParamDecl],
 ) -> Result<Func<'cx>, Error> {
     let mut cx = FnLoweringCtxt {
-        scopes: vec![],
-        build: FuncBuilder::new(name, def_span, ret_ty, lcx),
+        scopes: vec![Default::default()],
+        build: FuncBuilder::new(
+            name,
+            def_span,
+            ret_ty,
+            lcx,
+            params.len().try_into().unwrap(),
+        ),
         lcx,
     };
 
+    for param in params {
+        let decl_spec = &param.decl_spec.0;
+        let ty = lcx.lower_ty(&decl_spec.ty);
+        let tyl = lcx.layout_of(ty);
+        // Create all the parameter registers.
+        let _ = cx
+            .build
+            .new_reg(Some(param.declarator.0.decl.name().0), tyl);
+    }
+
+    for (i, param) in params.iter().enumerate() {
+        // For every param, we create an allocation and store the register into it.
+        let param_reg_data = &cx.build.ir.regs[i];
+        let name = param.declarator.0.decl.name().0;
+
+        let decl_spec = &param.decl_spec.0;
+        let decl_attr = decl_spec.attrs;
+        let tyl = param_reg_data.tyl;
+        let span = param.declarator.1;
+
+        let alloca_name = Symbol::intern(&format!("{}.local", name));
+        let ptr_to = cx.build.alloca(tyl.layout, Some(alloca_name), span);
+
+        let variable_info = VariableInfo {
+            def_span: span,
+            ptr_to,
+            decl_attr,
+            tyl,
+        };
+        let predeclared = cx.scopes.last_mut().unwrap().insert(name, variable_info);
+        if let Some(predeclared) = predeclared {
+            return Err(
+                Error::new(format!("parameter {name} has already been declared"), span)
+                    .note_spanned("already declared here", predeclared.def_span),
+            );
+        }
+
+        cx.build
+            .store(ptr_to, Operand::Reg(Register(i as _)), tyl.layout, span);
+    }
+
     cx.lower_block(body)?;
 
     if let Branch::Goto(BbIdx(u32::MAX)) = cx.build.cur_bb_mut().term {

analysis/src/lower/builder.rs

@@ -17,7 +17,13 @@ pub(super) struct FuncBuilder<'a, 'cx> {
 }
 
 impl<'a, 'cx> FuncBuilder<'a, 'cx> {
-    pub fn new(name: Symbol, def_span: Span, ret_ty: Ty<'cx>, lcx: &'a LoweringCx<'cx>) -> Self {
+    pub fn new(
+        name: Symbol,
+        def_span: Span,
+        ret_ty: Ty<'cx>,
+        lcx: &'a LoweringCx<'cx>,
+        arity: u32,
+    ) -> Self {
         Self {
             ir: Func {
                 regs: Vec::new(),
@@ -28,6 +34,7 @@ impl<'a, 'cx> FuncBuilder<'a, 'cx> {
                 name,
                 def_span,
                 ret_ty,
+                arity,
             },
             current_bb: BbIdx(0),
             lcx,

analysis/src/ty.rs

@@ -1,10 +1,14 @@
 use std::{
+    fmt::Display,
     hash::{Hash, Hasher},
     ops::Deref,
 };
 
 use indexmap::IndexMap;
-use parser::{ast::IntTy, Symbol};
+use parser::{
+    ast::{IntTy, IntTyKind, IntTySignedness},
+    Symbol,
+};
 
 use crate::ir::DefId;
 
@@ -74,3 +78,37 @@ impl Hash for EnumTy {
         self.def_id.hash(state)
     }
 }
+
+impl Display for Ty<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match **self {
+            TyKind::Void => f.write_str("void"),
+            TyKind::Char => f.write_str("char"),
+            TyKind::SChar => f.write_str("signed char"),
+            TyKind::UChar => f.write_str("unsigned char"),
+            TyKind::Integer(int) => {
+                match int.sign {
+                    IntTySignedness::Signed => f.write_str("signed "),
+                    IntTySignedness::Unsigned => f.write_str("unsigned "),
+                }?;
+                match int.kind {
+                    IntTyKind::Short => f.write_str("short"),
+                    IntTyKind::Int => f.write_str("int"),
+                    IntTyKind::Long => f.write_str("long"),
+                    IntTyKind::LongLong => f.write_str("long long"),
+                }?;
+                Ok(())
+            }
+            TyKind::Float => f.write_str("float"),
+            TyKind::Double => f.write_str("double"),
+            TyKind::LongDouble => f.write_str("long double"),
+            TyKind::Bool => f.write_str("_Bool"),
+            TyKind::Ptr(ty) => {
+                write!(f, "{ty}*")
+            }
+            TyKind::Union(_) => todo!(),
+            TyKind::Struct(_) => todo!(),
+            TyKind::Enum(_) => todo!(),
+        }
+    }
+}

parser/src/ast.rs

@@ -169,7 +169,7 @@ pub struct IntTy {
     pub kind: IntTyKind,
 }
 
-#[derive(Debug, DebugPls)]
+#[derive(Debug, DebugPls, Clone)]
 pub enum TypeSpecifier {
     Void,
     Char,
@@ -205,7 +205,7 @@ impl DebugPls for DeclAttr {
     }
 }
 
-#[derive(Debug, DebugPls)]
+#[derive(Debug, DebugPls, Clone)]
 pub struct DeclSpec {
     pub ty: TypeSpecifier,
     pub attrs: DeclAttr,
@@ -229,13 +229,13 @@ pub struct NormalDecl {
     pub init_declarators: Vec<Spanned<InitDecl>>,
 }
 
-#[derive(Debug, DebugPls)]
+#[derive(Debug, DebugPls, Clone)]
 pub struct FunctionParamDecl {
     pub decl_spec: Spanned<DeclSpec>,
     pub declarator: Spanned<Declarator>,
 }
 
-#[derive(Debug, DebugPls)]
+#[derive(Debug, DebugPls, Clone)]
 pub enum DirectDeclarator {
     Ident(Ident),
     WithParams {
@@ -244,7 +244,7 @@ pub enum DirectDeclarator {
     },
 }
 
-#[derive(Debug, DebugPls)]
+#[derive(Debug, DebugPls, Clone)]
 pub struct Declarator {
     pub decl: DirectDeclarator,
     pub pointer: bool,
@@ -265,7 +265,7 @@ pub enum ExternalDecl {
 pub type TranslationUnit = Vec<Spanned<ExternalDecl>>;
 
 impl Decl {
-    pub fn uwnrap_normal(&self) -> &NormalDecl {
+    pub fn unwrap_normal(&self) -> &NormalDecl {
         match self {
             Decl::Normal(decl) => decl,
             Decl::StaticAssert => {