adding loops

hblang/examples/if_statement.hb

@@ -6,6 +6,7 @@ main := ||: int {
 fib := |x: int|: int {
 	if x <= 2 {
 		return 1;
-	}
+	} else {
 		return fib(x - 1) + fib(x - 2);
+	}
 }

hblang/examples/loops.hb

@@ -0,0 +1,19 @@
+main := ||: int {
+	return fib(10);
+}
+
+fib := |n: int|: int {
+	a := 0;
+	b := 1;
+	loop {
+		c := a + b;
+		a = b;
+		b = c;
+		n = n - 1;
+		if n == 0 {
+			break;
+		}
+		continue;
+	}
+	return a;
+}

hblang/src/codegen.rs

@@ -179,6 +179,11 @@ struct RetReloc {
     size:         u16,
 }
 
+struct Loop {
+    offset: u32,
+    relocs: Vec<RetReloc>,
+}
+
 pub struct Codegen<'a> {
     path: &'a std::path::Path,
     ret: Expr<'a>,
@@ -190,6 +195,7 @@ pub struct Codegen<'a> {
     vars: Vec<Variable<'a>>,
     stack_relocs: Vec<StackReloc>,
     ret_relocs: Vec<RetReloc>,
+    loops: Vec<Loop>,
 }
 
 impl<'a> Codegen<'a> {
@@ -206,6 +212,7 @@ impl<'a> Codegen<'a> {
 
             stack_relocs: Default::default(),
             ret_relocs:   Default::default(),
+            loops:        Default::default(),
         }
     }
 
@@ -368,7 +375,7 @@ impl<'a> Codegen<'a> {
                 ty:  expeted.unwrap_or(Expr::Ident { name: "int" }),
                 loc: Loc::Imm(value),
             }),
-            E::If { cond, then } => {
+            E::If { cond, then, else_ } => {
                 let cond = self.expr(cond, Some(Expr::Ident { name: "bool" })).unwrap();
                 let reg = self.loc_to_reg(cond.loc);
                 let jump_offset = self.code.code.len() as u32;
@@ -377,13 +384,74 @@ impl<'a> Codegen<'a> {
                 self.gpa.free(reg);
 
                 self.expr(then, None);
-                let jump = self.code.code.len() as i16 - jump_offset as i16;
+
+                let jump;
+
+                if let Some(else_) = else_ {
+                    let else_jump_offset = self.code.code.len() as u32;
+                    println!("jump_offset: {:02x}", jump_offset);
+                    self.code.encode(instrs::jmp(0));
+
+                    jump = self.code.code.len() as i16 - jump_offset as i16;
+
+                    self.expr(else_, None);
+
+                    let jump = self.code.code.len() as i32 - else_jump_offset as i32;
+                    println!("jump: {:02x}", jump);
+                    self.code.code[else_jump_offset as usize + 1..][..4]
+                        .copy_from_slice(&jump.to_ne_bytes());
+                } else {
+                    jump = self.code.code.len() as i16 - jump_offset as i16;
+                }
+
                 println!("jump: {:02x}", jump);
                 self.code.code[jump_offset as usize + 3..][..2]
                     .copy_from_slice(&jump.to_ne_bytes());
 
                 None
             }
+            E::Loop { body } => {
+                let loop_start = self.code.code.len() as u32;
+                self.loops.push(Loop {
+                    offset: loop_start,
+                    relocs: Default::default(),
+                });
+                self.expr(body, None);
+
+                let loop_end = self.code.code.len();
+                self.code
+                    .encode(instrs::jmp(loop_start as i32 - loop_end as i32));
+                let loop_end = self.code.code.len() as u32;
+
+                let loop_ = self.loops.pop().unwrap();
+                for reloc in loop_.relocs {
+                    let dest = &mut self.code.code
+                        [reloc.offset as usize + reloc.instr_offset as usize..]
+                        [..reloc.size as usize];
+                    let offset = loop_end as i32 - reloc.offset as i32;
+                    dest.copy_from_slice(&offset.to_ne_bytes());
+                }
+
+                None
+            }
+            E::Break => {
+                let loop_ = self.loops.last_mut().unwrap();
+                let offset = self.code.code.len() as u32;
+                self.code.encode(instrs::jmp(0));
+                loop_.relocs.push(RetReloc {
+                    offset,
+                    instr_offset: 1,
+                    size: 4,
+                });
+                None
+            }
+            E::Continue => {
+                let loop_ = self.loops.last().unwrap();
+                let offset = self.code.code.len() as u32;
+                self.code
+                    .encode(instrs::jmp(loop_.offset as i32 - offset as i32));
+                None
+            }
             E::BinOp { left, op, right } => {
                 let left = self.expr(left, expeted).unwrap();
                 let right = self.expr(right, Some(left.ty)).unwrap();
@@ -404,6 +472,16 @@ impl<'a> Codegen<'a> {
                             loc: Loc::Reg(lhs),
                         });
                     }
+                    T::Eq => {
+                        self.code.encode(instrs::cmpu(lhs, lhs, rhs));
+                        self.gpa.free(rhs);
+                        self.code.encode(instrs::cmpui(lhs, lhs, 0));
+                        self.code.encode(instrs::not(lhs, lhs));
+                        return Some(Value {
+                            ty:  Expr::Ident { name: "bool" },
+                            loc: Loc::Reg(lhs),
+                        });
+                    }
                     T::FSlash => |reg0, reg1, reg2| instrs::diru64(reg0, ZERO, reg1, reg2),
                     T::Assign => return self.assign(left, right),
                     _ => unimplemented!("{:#?}", op),
@@ -635,5 +713,6 @@ mod tests {
         variables => include_str!("../examples/variables.hb");
         functions => include_str!("../examples/functions.hb");
         if_statements => include_str!("../examples/if_statement.hb");
+        loops => include_str!("../examples/loops.hb");
     }
 }

hblang/src/lexer.rs

@@ -30,11 +30,16 @@ pub enum TokenKind {
     Bor,
     Or,
     Le,
+    Eq,
     Semi,
     Colon,
     Comma,
     Return,
     If,
+    Else,
+    Loop,
+    Break,
+    Continue,
     Eof,
     Error,
 }
@@ -60,11 +65,16 @@ impl std::fmt::Display for TokenKind {
             T::Bor => "|",
             T::Or => "||",
             T::Le => "<=",
+            T::Eq => "==",
             T::Semi => ";",
             T::Colon => ":",
             T::Comma => ",",
             T::Return => "return",
             T::If => "if",
+            T::Else => "else",
+            T::Loop => "loop",
+            T::Break => "break",
+            T::Continue => "continue",
             T::Eof => "<eof>",
             T::Error => "<error>",
         };
@@ -76,7 +86,7 @@ impl TokenKind {
     pub fn precedence(&self) -> Option<u8> {
         Some(match self {
             Self::Assign => 1,
-            Self::Le => 21,
+            Self::Le | Self::Eq => 21,
             Self::Plus | Self::Minus => 23,
             Self::Star | Self::FSlash => 24,
             _ => return None,
@@ -167,6 +177,10 @@ impl<'a> Iterator for Lexer<'a> {
                     match ident {
                         b"return" => T::Return,
                         b"if" => T::If,
+                        b"else" => T::Else,
+                        b"loop" => T::Loop,
+                        b"break" => T::Break,
+                        b"continue" => T::Continue,
                         _ => T::Ident,
                     }
                 }
@@ -176,7 +190,10 @@ impl<'a> Iterator for Lexer<'a> {
                 },
                 b',' => T::Comma,
                 b';' => T::Semi,
-                b'=' => T::Assign,
+                b'=' => match self.advance_if(b'=') {
+                    true => T::Eq,
+                    false => T::Assign,
+                },
                 b'<' => match self.advance_if(b'=') {
                     true => T::Le,
                     false => T::Error,

hblang/src/parser.rs

@@ -84,8 +84,14 @@ impl<'a, 'b> Parser<'a, 'b> {
             TokenKind::If => {
                 let cond = self.ptr_expr();
                 let then = self.ptr_expr();
-                Expr::If { cond, then }
+                let else_ = self.advance_if(TokenKind::Else).then(|| self.ptr_expr());
+                Expr::If { cond, then, else_ }
             }
+            TokenKind::Loop => Expr::Loop {
+                body: self.ptr_expr(),
+            },
+            TokenKind::Break => Expr::Break,
+            TokenKind::Continue => Expr::Continue,
             TokenKind::Return => Expr::Return {
                 val: (self.token.kind != TokenKind::Semi).then(|| self.ptr_expr()),
             },
@@ -189,6 +195,8 @@ impl<'a, 'b> Parser<'a, 'b> {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Expr<'a> {
+    Break,
+    Continue,
     Decl {
         name: &'a str,
         val:  &'a Expr<'a>,
@@ -222,6 +230,10 @@ pub enum Expr<'a> {
     If {
         cond:  &'a Expr<'a>,
         then:  &'a Expr<'a>,
+        else_: Option<&'a Expr<'a>>,
+    },
+    Loop {
+        body: &'a Expr<'a>,
     },
 }
 
@@ -232,7 +244,16 @@ impl<'a> std::fmt::Display for Expr<'a> {
         }
 
         match *self {
-            Self::If { cond, then } => write!(f, "if {} {}", cond, then),
+            Self::Break => write!(f, "break;"),
+            Self::Continue => write!(f, "continue;"),
+            Self::If { cond, then, else_ } => {
+                write!(f, "if {} {}", cond, then)?;
+                if let Some(else_) = else_ {
+                    write!(f, " else {}", else_)?;
+                }
+                Ok(())
+            }
+            Self::Loop { body } => write!(f, "loop {}", body),
             Self::Decl { name, val } => write!(f, "{} := {}", name, val),
             Self::Closure { ret, body, args } => {
                 write!(f, "|")?;

hblang/src/tests.rs

@@ -12,7 +12,7 @@ pub fn run_test(name: &'static str, input: &'static str, test: fn(&'static str,
     test(input, &mut output);
 
     let mut root = PathBuf::from(std::env::var("PT_TEST_ROOT").unwrap_or("tests".to_string()));
-    root.push(name);
+    root.push(name.replace("::", "_"));
     root.set_extension("txt");
 
     let expected = std::fs::read_to_string(&root).unwrap_or_default();

hblang/tests/hblang_codegen_tests_if_statements.txt

@@ -0,0 +1,2 @@
+ret: 55
+status: Ok(())

hblang/tests/hblang_codegen_tests_loops.txt

@@ -0,0 +1,2 @@
+ret: 55
+status: Ok(())