_var_arg

README.md

@@ -8,7 +8,7 @@ A very cool language
 * Growing [standard library](https://github.com/antpiasecki/zern/tree/main/src/std)
 * Produces tiny static executables (11KB for `hello.zr`)
 * No libc required!
-* Has the pipe operator
+* Has the pipe operator, variadics, dynamic arrays, hashmaps, etc.
 
 ## Syntax
 ```rust

src/codegen_x86_64.rs

@@ -1,7 +1,7 @@
 use std::{collections::HashMap, fmt::Write};
 
 use crate::{
-    parser::{Expr, Stmt},
+    parser::{Expr, Params, Stmt},
     symbol_table::SymbolTable,
     tokenizer::{Token, TokenType, ZernError, error},
 };
@@ -151,21 +151,6 @@ _builtin_syscall:
     mov r9, [rsp+8]
     syscall
     ret
-
-section .text.io.printf
-io.printf:
-    push rbp
-    mov rbp, rsp
-    sub rsp, 48
-    mov [rsp], rsi
-    mov [rsp + 8], rdx
-    mov [rsp + 16], rcx
-    mov [rsp + 24], r8
-    mov [rsp + 32], r9
-    lea rsi, [rsp]
-    call io._printf_impl
-    leave
-    ret
 "
         );
 
@@ -317,9 +302,13 @@ _builtin_environ:
                 emit!(&mut self.output, "    mov rbp, rsp");
                 emit!(&mut self.output, "    sub rsp, 256"); // TODO: eww
 
+                match params {
+                    Params::Normal(params) => {
                         for (i, param) in params.iter().enumerate() {
-                    let offset = env
+                            let offset = env.define_var(
-                        .define_var(param.var_name.lexeme.clone(), param.var_type.lexeme.clone());
+                                param.var_name.lexeme.clone(),
+                                param.var_type.lexeme.clone(),
+                            );
                             if let Some(reg) = REGISTERS.get(i) {
                                 emit!(&mut self.output, "    mov QWORD [rbp-{}], {}", offset, reg);
                             } else {
@@ -332,6 +321,18 @@ _builtin_environ:
                                 emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
                             }
                         }
+                    }
+                    Params::Variadic => {
+                        emit!(&mut self.output, "    sub rsp, 48");
+                        emit!(&mut self.output, "    mov [rbp - 8], rdi");
+                        emit!(&mut self.output, "    mov [rbp - 16], rsi");
+                        emit!(&mut self.output, "    mov [rbp - 24], rdx");
+                        emit!(&mut self.output, "    mov [rbp - 32], rcx");
+                        emit!(&mut self.output, "    mov [rbp - 40], r8");
+                        emit!(&mut self.output, "    mov [rbp - 48], r9");
+                        env.next_offset += 48;
+                    }
+                }
 
                 self.compile_stmt(env, body)?;
 
@@ -619,6 +620,12 @@ _builtin_environ:
                 paren: _,
                 args,
             } => {
+                if let Expr::Variable(callee_name) = &**callee
+                    && callee_name.lexeme == "_var_arg"
+                {
+                    return self.emit_var_arg(env, &args[0]);
+                }
+
                 for arg in args {
                     self.compile_expr(env, arg)?;
                     emit!(&mut self.output, "    push rax");
@@ -732,7 +739,6 @@ _builtin_environ:
             Expr::New(struct_name) => {
                 let struct_fields = &self.symbol_table.structs[&struct_name.lexeme];
 
-                // TODO: panic on mem.alloc error
                 let memory_size = struct_fields.len() * 8;
                 emit!(&mut self.output, "    mov rdi, {}", memory_size);
                 emit!(&mut self.output, "    call mem.alloc");
@@ -789,4 +795,33 @@ _builtin_environ:
 
         Ok(field.offset)
     }
+
+    fn emit_var_arg(&mut self, env: &mut Env, index_expr: &Expr) -> Result<(), ZernError> {
+        self.compile_expr(env, index_expr)?;
+        emit!(&mut self.output, " mov r10, rax");
+
+        let stack_label = self.label();
+        let done_label = self.label();
+
+        emit!(&mut self.output, " cmp r10, 6");
+        emit!(&mut self.output, " jge {}", stack_label);
+
+        // < 6
+        emit!(&mut self.output, " mov rax, r10");
+        emit!(&mut self.output, " inc rax");
+        emit!(&mut self.output, " shl rax, 3");
+        emit!(&mut self.output, " neg rax");
+        emit!(&mut self.output, " mov rax, [rbp + rax]");
+        emit!(&mut self.output, " jmp {}", done_label);
+
+        // >= 6
+        emit!(&mut self.output, "{}:", stack_label);
+        emit!(&mut self.output, " mov rax, r10");
+        emit!(&mut self.output, " sub rax, 6");
+        emit!(&mut self.output, " shl rax, 3");
+        emit!(&mut self.output, " mov rax, [rbp + 16 + rax]");
+
+        emit!(&mut self.output, "{}:", done_label);
+        Ok(())
+    }
 }

src/parser.rs

@@ -6,6 +6,12 @@ pub struct Param {
     pub var_name: Token,
 }
 
+#[derive(Debug, Clone)]
+pub enum Params {
+    Normal(Vec<Param>),
+    Variadic,
+}
+
 #[derive(Debug, Clone)]
 pub enum Stmt {
     Expression(Expr),
@@ -38,7 +44,7 @@ pub enum Stmt {
     },
     Function {
         name: Token,
-        params: Vec<Param>,
+        params: Params,
         return_type: Token,
         body: Box<Stmt>,
         exported: bool,
@@ -164,13 +170,19 @@ impl Parser {
         let name = self.consume(TokenType::Identifier, "expected function name")?;
         self.consume(TokenType::LeftBracket, "expected '[' after function name")?;
 
+        let mut is_variadic = false;
         let mut params = vec![];
         if !self.check(&TokenType::RightBracket) {
+            if self.match_token(&[TokenType::DoubleDot]) {
+                is_variadic = true;
+            } else {
                 loop {
-                let var_name = self.consume(TokenType::Identifier, "expected parameter name")?;
+                    let var_name =
+                        self.consume(TokenType::Identifier, "expected parameter name")?;
                     self.consume(TokenType::Colon, "expected ':' after parameter name")?;
 
-                let var_type = self.consume(TokenType::Identifier, "expected parameter type")?;
+                    let var_type =
+                        self.consume(TokenType::Identifier, "expected parameter type")?;
 
                     params.push(Param { var_type, var_name });
                     if !self.match_token(&[TokenType::Comma]) {
@@ -178,6 +190,7 @@ impl Parser {
                     }
                 }
             }
+        }
 
         self.consume(TokenType::RightBracket, "expected ']' after arguments")?;
         self.consume(TokenType::Colon, "expected ':' after '['")?;
@@ -189,7 +202,11 @@ impl Parser {
 
         Ok(Stmt::Function {
             name,
-            params,
+            params: if is_variadic {
+                Params::Variadic
+            } else {
+                Params::Normal(params)
+            },
             return_type,
             body,
             exported,

src/std/std.zr

@@ -5,6 +5,7 @@ const ERR_READ_FAILED       = 3
 const ERR_WRITE_FAILED      = 4
 const ERR_ALLOC_FAILED      = 5
 const ERR_CONNECTION_FAILED = 6
+const ERR_KEY_ERROR         = 7
 
 func err.code[] : i64
     return mem.read64(_builtin_err_code())
@@ -263,24 +264,26 @@ func mem.write16be[x: ptr, d: i64] : void
 func mem.write64[x: ptr, d: any] : void
     _builtin_set64(x, d)
 
-// see emit_prologue for the io.printf wrapper
+func io.printf[..] : void
-func io._printf_impl[s: ptr, args: ptr] : void
+    let s: ptr = _var_arg(0) as ptr
+    let i: i64 = 1
+
     while s[0]
         if s[0] == '%'
             s = s + 1
 
             if s[0] == 'd'
-                io.print_i64(mem.read64(args))
+                io.print_i64(_var_arg(i))
-                args = args + 8
+                i = i + 1
             else if s[0] == 'x'
-                io.print_i64_hex(mem.read64(args))
+                io.print_i64_hex(_var_arg(i))
-                args = args + 8
+                i = i + 1
             else if s[0] == 's'
-                io.print(mem.read64(args) as str)
+                io.print(_var_arg(i) as str)
-                args = args + 8
+                i = i + 1
             else if s[0] == 'c'
-                io.print_char(mem.read64(args) as u8)
+                io.print_char(_var_arg(i) as u8)
-                args = args + 8
+                i = i + 1
             else if s[0] == '%'
                 io.print_char('%')
             else if s[0] == 0
@@ -846,6 +849,89 @@ func array.concat[a: Array, b: Array] : Array
         array.set(new_array, a->size + i, array.nth(b, i))
     return new_array
 
+const HashMap._TABLE_SIZE = 100
+
+struct HashMap
+    table: Array
+
+struct HashMap._Node
+    key: str
+    value: any
+    next: HashMap._Node
+
+func HashMap.new[] : HashMap
+    let map: HashMap = new HashMap
+    map->table = array.new_preallocated_and_zeroed(HashMap._TABLE_SIZE)
+    return map
+
+func HashMap.insert[map: HashMap, key: str, value: any] : void
+    let index: i64 = HashMap._djb2(key)
+    let current: HashMap._Node = array.nth(map->table, index)
+
+    while current as ptr
+        if str.equal(current->key, key)
+            current->value = value
+            return 0
+        current = current->next
+
+    let new_node: HashMap._Node = new HashMap._Node
+    new_node->key = str.make_copy(key)
+    new_node->value = value
+    new_node->next = array.nth(map->table, index)
+    array.set(map->table, index, new_node)
+
+func HashMap.get?[map: HashMap, key: str] : any
+    err.clear()
+    let index: i64 = HashMap._djb2(key)
+    let current: HashMap._Node = array.nth(map->table, index)
+
+    while current as ptr
+        if str.equal(current->key, key)
+            return current->value
+        current = current->next
+    
+    err.set(ERR_KEY_ERROR, "key not found")
+    return 0
+
+func HashMap.delete[map: HashMap, key: str] : void
+    let index: i64 = HashMap._djb2(key)
+    let current: HashMap._Node = array.nth(map->table, index)
+    let prev: HashMap._Node = 0 as HashMap._Node
+
+    while current as ptr
+        if str.equal(current->key, key)
+            if prev as ptr
+                prev->next = current->next
+            else
+                array.set(map->table, index, current->next)
+            
+            mem.free(current->key)
+            mem.free(current)
+            return 0
+
+        prev = current
+        current = current->next
+
+func HashMap._djb2[key: str] : i64
+    let hash: i64 = 5381 
+    let key_len: i64 = str.len(key)
+    for i in 0..key_len
+        hash = ((hash << 5) + hash) + key[i]
+    hash = (hash & 0x7fffffffffffffff) // prevent negative
+    return hash % HashMap._TABLE_SIZE
+
+func HashMap.free[map: HashMap] : void
+    for i in 0..HashMap._TABLE_SIZE
+        let current: HashMap._Node = array.nth(map->table, i)
+        while current as ptr
+            let tmp: HashMap._Node = current
+            current = current->next
+            mem.free(tmp->key)
+            mem.free(tmp)
+
+    array.free(map->table)
+    mem.free(map)
+
 func alg.quicksort[arr: Array] : void
     alg._do_quicksort(arr, 0, arr->size - 1)
 
@@ -923,7 +1009,7 @@ func os.urandom?[n: i64]: ptr
     let fd: i64 = _builtin_syscall(SYS_openat, -100, "/dev/urandom", 0, 0)
     if fd < 0
         mem.free(buffer)
-        err.set(ERR_READ_FAILED, "os.urandom?: failed to open /dev/urandom")
+        err.set(ERR_OPEN_FAILED, "os.urandom?: failed to open /dev/urandom")
         return 0 as ptr
 
     let bytes_read: i64 = _builtin_syscall(SYS_read, fd, buffer, n)

src/symbol_table.rs

@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 
 use crate::{
-    parser::Stmt,
+    parser::{Params, Stmt},
     tokenizer::{ZernError, error},
 };
 
@@ -54,8 +54,8 @@ impl SymbolTable {
                     FnType::new("void", vec!["ptr", "i64"]),
                 ),
                 ("_builtin_syscall".into(), FnType::new_variadic("i64")),
-                ("io.printf".into(), FnType::new_variadic("void")),
                 ("_builtin_environ".into(), FnType::new("ptr", vec![])),
+                ("_var_arg".into(), FnType::new("any", vec!["i64"])),
             ]),
             constants: HashMap::new(),
             structs: HashMap::new(),
@@ -66,10 +66,7 @@ impl SymbolTable {
         match stmt {
             Stmt::Const { name, value } => {
                 if self.is_name_defined(&name.lexeme) {
-                    return error!(
+                    return error!(name.loc, format!("tried to redefine '{}'", name.lexeme));
-                        name.loc,
-                        format!("tried to redefine constant '{}'", name.lexeme)
-                    );
                 }
                 if value.lexeme.starts_with("0x") {
                     self.constants.insert(
@@ -103,13 +100,24 @@ impl SymbolTable {
                 if self.is_name_defined(&name.lexeme) {
                     return error!(name.loc, format!("tried to redefine '{}'", name.lexeme));
                 }
-                self.functions.insert(
+                match params {
+                    Params::Normal(params) => self.functions.insert(
                         name.lexeme.clone(),
                         FnType {
                             return_type: return_type.lexeme.clone(),
-                        params: Some(params.iter().map(|x| x.var_type.lexeme.clone()).collect()),
+                            params: Some(
+                                params.iter().map(|x| x.var_type.lexeme.clone()).collect(),
+                            ),
                         },
-                );
+                    ),
+                    Params::Variadic => self.functions.insert(
+                        name.lexeme.clone(),
+                        FnType {
+                            return_type: return_type.lexeme.clone(),
+                            params: None,
+                        },
+                    ),
+                };
             }
             Stmt::Struct { name, fields } => {
                 if self.is_name_defined(&name.lexeme) {

src/typechecker.rs

@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 
 use crate::{
-    parser::{Expr, Stmt},
+    parser::{Expr, Params, Stmt},
     symbol_table::{SymbolTable, Type},
     tokenizer::{TokenType, ZernError, error},
 };
@@ -166,8 +166,39 @@ impl<'a> TypeChecker<'a> {
                 body,
                 exported: _,
             } => {
-                if name.lexeme == "main" && return_type.lexeme != "i64" {
+                if name.lexeme == "main" {
-                    return error!(&name.loc, "main must return i64");
+                    if return_type.lexeme != "i64" {
+                        return error!(&name.loc, "main function must return i64");
+                    }
+
+                    match params {
+                        Params::Normal(params) => {
+                            if !params.is_empty() && params.len() != 2 {
+                                return error!(
+                                    &name.loc,
+                                    "main function must accept 0 or 2 parameters"
+                                );
+                            }
+
+                            if params.len() == 2 {
+                                if params[0].var_type.lexeme != "i64" {
+                                    return error!(
+                                        &name.loc,
+                                        "first parameter of the main function must be a i64"
+                                    );
+                                }
+                                if params[1].var_type.lexeme != "ptr" {
+                                    return error!(
+                                        &name.loc,
+                                        "second parameter of the main function must be a ptr"
+                                    );
+                                }
+                            }
+                        }
+                        Params::Variadic => {
+                            return error!(&name.loc, "main function cannot be variadic");
+                        }
+                    }
                 }
 
                 if !self.is_valid_type_name(&return_type.lexeme) {
@@ -181,6 +212,8 @@ impl<'a> TypeChecker<'a> {
 
                 env.push_scope();
 
+                match params {
+                    Params::Normal(params) => {
                         for param in params {
                             if !self.is_valid_type_name(&param.var_type.lexeme) {
                                 return error!(
@@ -189,7 +222,13 @@ impl<'a> TypeChecker<'a> {
                                 );
                             }
 
-                    env.define_var(param.var_name.lexeme.clone(), param.var_type.lexeme.clone());
+                            env.define_var(
+                                param.var_name.lexeme.clone(),
+                                param.var_type.lexeme.clone(),
+                            );
+                        }
+                    }
+                    Params::Variadic => {}
                 }
 
                 self.typecheck_stmt(env, body)?;

test.zr

@@ -4,22 +4,17 @@ func run_test[x: str] : void
 
     for i in 0..build_blacklist->size
         if str.equal(x, array.nth(build_blacklist, i))
-            io.print("Skipping ")
+            io.printf("Skipping %s...\n", x)
-            io.print(x)
-            io.println("...")
             return 0
 
-    io.print("Building ")
+    io.printf("Building %s...\n", x)
-    io.print(x)
-    io.print("... ")
 
     let build_start_time: i64 = os.time()
     if must(os.run_shell_command?(str.concat("./target/release/zern ", x))) != 0
         os.exit(1)
     let build_end_time: i64 = os.time()
 
-    io.print_i64(build_end_time - build_start_time)
+    io.printf("%dms\n", build_end_time - build_start_time)
-    io.println("ms")
 
     for i in 0..run_blacklist->size
         if str.find(x, array.nth(run_blacklist, i)) != -1
@@ -28,9 +23,7 @@ func run_test[x: str] : void
             io.println("...")
             return 0
 
-    io.print("Running ")
+    io.printf("Running %s...\n", x)
-    io.print(x)
-    io.println("...")
 
     let run_cmd: str = "./out"
     if str.equal(x, "examples/curl.zr")
@@ -43,11 +36,7 @@ func run_test[x: str] : void
         os.exit(1)
     let run_end_time: i64 = os.time()
 
-    io.print("Running ")
+    io.printf("Running %s took %dms\n", x, run_end_time - run_start_time)
-    io.print(x)
-    io.print(" took ")
-    io.print_i64(run_end_time - run_start_time)
-    io.println("ms")
 
 func run_directory[dir: str] : void
     let files: Array = must(os.list_directory?(dir))