remove enums

src/codegen_x86_64.rs

@@ -77,14 +77,12 @@ pub struct CodegenX86_64<'a> {
     data_counter: usize,
     pub symbol_table: &'a SymbolTable,
     pub expr_types: &'a HashMap<usize, String>,
-    emit_debug: bool,
 }
 
 impl<'a> CodegenX86_64<'a> {
     pub fn new(
         symbol_table: &'a SymbolTable,
         expr_types: &'a HashMap<usize, String>,
-        emit_debug: bool,
     ) -> CodegenX86_64<'a> {
         CodegenX86_64 {
             output: String::new(),
@@ -93,7 +91,6 @@ impl<'a> CodegenX86_64<'a> {
             data_counter: 1,
             symbol_table,
             expr_types,
-            emit_debug,
         }
     }
 
@@ -103,58 +100,60 @@ impl<'a> CodegenX86_64<'a> {
     }
 
     pub fn get_output(&self) -> String {
-        format!("section .data\n{}{}", self.data_section, self.output)
+        format!(".section .data\n{}{}", self.data_section, self.output)
     }
 
     pub fn emit_prologue(&mut self, use_crt: bool) -> Result<(), ZernError> {
         emit!(
             &mut self.output,
-            "section .note.GNU-stack
+            ".intel_syntax noprefix
-    db 0
 
-section .bss
+.section .note.GNU-stack
-    _heap_head: resq 1
+    .byte 0
-    _heap_tail: resq 1
-    _environ: resq 1
 
-section .text._builtin_heap_head
+.section .bss
+    _heap_head: .zero 8
+    _heap_tail: .zero 8
+    _environ: .zero 8
+
+.section .text._builtin_heap_head
 _builtin_heap_head:
-    lea rax, [rel _heap_head]
+    lea rax, [rip + _heap_head]
     ret
 
-section .text._builtin_heap_tail
+.section .text._builtin_heap_tail
 _builtin_heap_tail:
-    lea rax, [rel _heap_tail]
+    lea rax, [rip + _heap_tail]
     ret
 
-section .text._builtin_read64
+.section .text._builtin_read64
 _builtin_read64:
-    mov rax, QWORD [rdi]
+    mov rax, QWORD PTR [rdi]
     ret
 
-section .text._builtin_set64
+.section .text._builtin_set64
 _builtin_set64:
     mov [rdi], rsi
     ret
 
-section .text._builtin_cvtsi2sd
+.section .text._builtin_cvtsi2sd
 _builtin_cvtsi2sd:
     cvtsi2sd xmm0, rdi
     movq rax, xmm0
     ret
 
-section .text._builtin_cvttsd2si
+.section .text._builtin_cvttsd2si
 _builtin_cvttsd2si:
     cvttsd2si rax, xmm0
     ret
 
-section .text._builtin_f64_to_float
+.section .text._builtin_f64_to_float
 _builtin_f64_to_float:
     cvtsd2ss xmm0, xmm0
     movd eax, xmm0
     ret
 
-section .text._builtin_syscall
+.section .text._builtin_syscall
 _builtin_syscall:
     mov rax, rdi
     mov rdi, rsi
@@ -172,26 +171,26 @@ _builtin_syscall:
             emit!(
                 &mut self.output,
                 "
-section .text._builtin_environ
+.section .text._builtin_environ
 _builtin_environ:
-    lea rax, [rel _environ]
+    lea rax, [rip + _environ]
     mov rax, [rax]
     ret
 
-global _start
+.globl _start
-section .text
+.section .text
 _start:
     xor rbp, rbp
-    ; setup args
+    // setup args
     pop rdi
     mov rsi, rsp
-    ; save environ
+    // save environ
     lea rdx, [rsi + rdi*8 + 8]
-    lea rax, [rel _environ]
+    lea rax, [rip + _environ]
     mov [rax], rdx
-    ; align stack
+    // align stack
     and rsp, -16
-    ; exit(main())
+    // exit(main())
     call main
     mov rdi, rax
     mov rax, 60
@@ -202,10 +201,10 @@ _start:
             emit!(
                 &mut self.output,
                 "
-section .text._builtin_environ
+.section .text._builtin_environ
 _builtin_environ:
-    extern environ
+    .extern environ
-    mov rax, [rel environ]
+    mov rax, [rip + environ]
     ret
 "
             );
@@ -239,7 +238,7 @@ _builtin_environ:
 
                 self.compile_expr(env, initializer)?;
                 let offset = env.define_var(name.lexeme.clone(), var_type);
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
             }
             Stmt::Assign { left, op, value } => {
                 self.compile_expr(env, value)?;
@@ -250,7 +249,7 @@ _builtin_environ:
                         let var = env.get_var(&name.lexeme).unwrap();
                         emit!(
                             &mut self.output,
-                            "    mov QWORD [rbp-{}], rax",
+                            "    mov QWORD PTR [rbp-{}], rax",
                             var.stack_offset,
                         );
                     }
@@ -266,7 +265,7 @@ _builtin_environ:
                         emit!(&mut self.output, "    pop rbx");
                         emit!(&mut self.output, "    add rbx, rax");
                         emit!(&mut self.output, "    pop rax");
-                        emit!(&mut self.output, "    mov BYTE [rbx], al");
+                        emit!(&mut self.output, "    mov BYTE PTR [rbx], al");
                     }
                     ExprKind::MemberAccess { left, field } => {
                         emit!(&mut self.output, "    push rax");
@@ -275,7 +274,7 @@ _builtin_environ:
 
                         self.compile_expr(env, left)?;
                         emit!(&mut self.output, "    pop rbx");
-                        emit!(&mut self.output, "    mov QWORD [rax+{}], rbx", offset);
+                        emit!(&mut self.output, "    mov QWORD PTR [rax+{}], rbx", offset);
                     }
                     _ => return error!(&op.loc, "invalid assignment target"),
                 };
@@ -302,7 +301,12 @@ _builtin_environ:
                             env.define_var(target.lexeme.clone(), types[i].to_string())
                         }
                     };
-                    emit!(&mut self.output, "    mov QWORD [rbp-{}], {}", offset, reg);
+                    emit!(
+                        &mut self.output,
+                        "    mov QWORD PTR [rbp-{}], {}",
+                        offset,
+                        reg
+                    );
                 }
             }
             Stmt::Const { .. } => {
@@ -365,14 +369,11 @@ _builtin_environ:
                 exported,
             } => {
                 let name = &name.lexeme;
-                if self.emit_debug || *exported || name == "main" {
+                if *exported || name == "main" {
-                    emit!(
+                    emit!(&mut self.output, ".globl {0}", name);
-                        &mut self.output,
-                        "global {0}:function ({0}.end - {0})",
-                        name
-                    );
                 }
-                emit!(&mut self.output, "section .text.{}", name);
+                emit!(&mut self.output, ".type {0}, @function", name);
+                emit!(&mut self.output, ".section .text.{}", name);
                 emit!(&mut self.output, "{}:", name);
                 emit!(&mut self.output, "    push rbp");
                 emit!(&mut self.output, "    mov rbp, rsp");
@@ -388,15 +389,20 @@ _builtin_environ:
                                 param.var_type.lexeme.clone(),
                             );
                             if let Some(reg) = REGISTERS.get(i) {
-                                emit!(&mut self.output, "    mov QWORD [rbp-{}], {}", offset, reg);
+                                emit!(
+                                    &mut self.output,
+                                    "    mov QWORD PTR [rbp-{}], {}",
+                                    offset,
+                                    reg
+                                );
                             } else {
                                 let stack_offset = 16 + 8 * (i - REGISTERS.len());
                                 emit!(
                                     &mut self.output,
-                                    "    mov rax, QWORD [rbp+{}]",
+                                    "    mov rax, QWORD PTR [rbp+{}]",
                                     stack_offset
                                 );
-                                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                             }
                         }
                     }
@@ -423,7 +429,7 @@ _builtin_environ:
                     emit!(&mut self.output, "    ret");
                 }
 
-                emit!(&mut self.output, ".end:");
+                emit!(&mut self.output, ".size {0}, . - {0}", name);
 
                 // patch the stack size after we know how much we actually need
                 let patch = format!("    sub rsp, {:<10}", (env.next_offset + 15) & !15);
@@ -465,21 +471,29 @@ _builtin_environ:
                 let offset = env.define_var(var.lexeme.clone(), "i64".into());
 
                 self.compile_expr(env, start)?;
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                 self.compile_expr(env, end)?;
                 let end_offset = env.next_offset;
                 env.next_offset += 8;
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", end_offset);
+                emit!(
+                    &mut self.output,
+                    "    mov QWORD PTR [rbp-{}], rax",
+                    end_offset
+                );
                 emit!(&mut self.output, "{}:", env.loop_begin_label);
-                emit!(&mut self.output, "    mov rax, QWORD [rbp-{}]", offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rbp-{}]", offset);
-                emit!(&mut self.output, "    mov rcx, QWORD [rbp-{}]", end_offset);
+                emit!(
+                    &mut self.output,
+                    "    mov rcx, QWORD PTR [rbp-{}]",
+                    end_offset
+                );
                 emit!(&mut self.output, "    cmp rax, rcx");
                 emit!(&mut self.output, "    jge {}", env.loop_end_label);
                 self.compile_stmt(env, body)?;
                 emit!(&mut self.output, "{}:", env.loop_continue_label);
-                emit!(&mut self.output, "    mov rax, QWORD [rbp-{}]", offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rbp-{}]", offset);
                 emit!(&mut self.output, "    add rax, 1");
-                emit!(&mut self.output, "    mov QWORD [rbp-{}], rax", offset);
+                emit!(&mut self.output, "    mov QWORD PTR [rbp-{}], rax", offset);
                 emit!(&mut self.output, "    jmp {}", env.loop_begin_label);
                 emit!(&mut self.output, "{}:", env.loop_end_label);
                 env.pop_scope();
@@ -495,14 +509,11 @@ _builtin_environ:
                 emit!(&mut self.output, "    jmp {}", env.loop_continue_label);
             }
             Stmt::Extern(name) => {
-                emit!(&mut self.output, "extern {}", name.lexeme);
+                emit!(&mut self.output, ".extern {}", name.lexeme);
             }
             Stmt::Struct { .. } => {
                 // handled in SymbolTable
             }
-            Stmt::Enum { .. } => {
-                // handled in SymbolTable
-            }
         }
         Ok(())
     }
@@ -610,11 +621,8 @@ _builtin_environ:
                     emit!(&mut self.output, "    mov rax, {}", token.lexeme);
                 }
                 TokenType::FloatLiteral => {
-                    emit!(
+                    let value: f64 = token.lexeme.parse().unwrap();
-                        &mut self.output,
+                    emit!(&mut self.output, "    mov rax, {}", value.to_bits());
-                        "    mov rax, __float64__({})",
-                        token.lexeme
-                    );
                 }
                 TokenType::CharLiteral => {
                     emit!(
@@ -635,10 +643,10 @@ _builtin_environ:
                         .chain(std::iter::once("0".into()))
                         .collect::<Vec<_>>()
                         .join(",");
-                    emit!(&mut self.data_section, "    {} db {}", label, charcodes);
+                    emit!(&mut self.data_section, "    {}: .byte {}", label, charcodes);
                     self.data_counter += 1;
 
-                    emit!(&mut self.output, "    mov rax, {}", label);
+                    emit!(&mut self.output, "    lea rax, [rip + {}]", label);
                 }
                 TokenType::True => {
                     emit!(&mut self.output, "    mov rax, 1");
@@ -679,7 +687,7 @@ _builtin_environ:
                     let var = env.get_var(&name.lexeme).unwrap();
                     emit!(
                         &mut self.output,
-                        "    mov rax, QWORD [rbp-{}]",
+                        "    mov rax, QWORD PTR [rbp-{}]",
                         var.stack_offset,
                     );
                 }
@@ -767,12 +775,12 @@ _builtin_environ:
                 self.compile_expr(env, index)?;
                 emit!(&mut self.output, "    pop rbx");
                 emit!(&mut self.output, "    add rax, rbx");
-                emit!(&mut self.output, "    movzx rax, BYTE [rax]");
+                emit!(&mut self.output, "    movzx rax, BYTE PTR [rax]");
             }
             ExprKind::AddrOf { op, expr } => match &expr.kind {
                 ExprKind::Variable(name) => {
                     if self.symbol_table.functions.contains_key(&name.lexeme) {
-                        emit!(&mut self.output, "    mov rax, {}", name.lexeme);
+                        emit!(&mut self.output, "    lea rax, [rip + {}]", name.lexeme);
                     } else {
                         let var = match env.get_var(&name.lexeme) {
                             Some(x) => x,
@@ -785,7 +793,7 @@ _builtin_environ:
                         };
                         emit!(
                             &mut self.output,
-                            "    lea rax, QWORD [rbp-{}]",
+                            "    lea rax, QWORD PTR [rbp-{}]",
                             var.stack_offset,
                         );
                     }
@@ -821,7 +829,7 @@ _builtin_environ:
             ExprKind::MemberAccess { left, field } => {
                 let offset = self.get_field_offset(left, field)?;
                 self.compile_expr(env, left)?;
-                emit!(&mut self.output, "    mov rax, QWORD [rax+{}]", offset);
+                emit!(&mut self.output, "    mov rax, QWORD PTR [rax+{}]", offset);
             }
             ExprKind::Cast { expr, type_name: _ } => {
                 self.compile_expr(env, expr)?;
@@ -857,7 +865,11 @@ _builtin_environ:
         let mut int_idx = 0;
         for (i, arg_type) in arg_types.iter().enumerate().take(to_register) {
             let offset = 8 * (arg_count - 1 - i);
-            emit!(&mut self.output, "    mov rax, QWORD [rsp + {}]", offset);
+            emit!(
+                &mut self.output,
+                "    mov rax, QWORD PTR [rsp + {}]",
+                offset
+            );
             if arg_type == "f64" {
                 emit!(&mut self.output, "    movq xmm{}, rax", fp_idx);
                 fp_idx += 1;
@@ -875,7 +887,7 @@ _builtin_environ:
             let offset = 8 * (arg_count - 1 - arg_idx);
             emit!(
                 &mut self.output,
-                "    mov rax, QWORD [rsp + {}]",
+                "    mov rax, QWORD PTR [rsp + {}]",
                 offset + 8 * i
             );
             emit!(&mut self.output, "    push rax");

src/main.rs

@@ -38,8 +38,7 @@ fn compile_file(args: Args) -> Result<(), ZernError> {
         typechecker.typecheck_stmt(&mut typechecker::Env::new(), stmt)?;
     }
 
-    let mut codegen =
+    let mut codegen = codegen_x86_64::CodegenX86_64::new(&symbol_table, &typechecker.expr_types);
-        codegen_x86_64::CodegenX86_64::new(&symbol_table, &typechecker.expr_types, args.emit_debug);
     codegen.emit_prologue(args.use_crt)?;
     for stmt in statements {
         codegen.compile_stmt(&mut codegen_x86_64::Env::new(), &stmt)?;
@@ -50,7 +49,9 @@ fn compile_file(args: Args) -> Result<(), ZernError> {
 
         fs::write(format!("{out}.s"), codegen.get_output()).unwrap();
 
-        run_command(format!("nasm -f elf64 -o {out}.o {out}.s"));
+        let debug_flag = if args.emit_debug { "-g" } else { "" };
+
+        run_command(format!("as --64 {debug_flag} -o {out}.o {out}.s"));
 
         if args.use_crt {
             run_command(format!(

src/parser.rs

@@ -77,10 +77,6 @@ pub enum Stmt {
         name: Token,
         fields: Vec<Param>,
     },
-    Enum {
-        name: Token,
-        variants: Vec<Token>,
-    },
 }
 
 pub static NEXT_EXPR_ID: AtomicUsize = AtomicUsize::new(0);
@@ -195,9 +191,6 @@ impl Parser {
             if self.match_token(&[TokenType::KeywordStruct]) {
                 return self.struct_declaration();
             }
-            if self.match_token(&[TokenType::KeywordEnum]) {
-                return self.enum_declaration();
-            }
             return error!(
                 self.peek().loc,
                 "statements not allowed outside function body"
@@ -281,21 +274,6 @@ impl Parser {
         Ok(Stmt::Struct { name, fields })
     }
 
-    fn enum_declaration(&mut self) -> Result<Stmt, ZernError> {
-        let name = self.consume(TokenType::Identifier, "expected enum name")?;
-
-        self.consume(TokenType::Indent, "expected indent after enum name")?;
-
-        let mut variants = vec![];
-        while !self.eof() && !self.check(&TokenType::Dedent) {
-            variants.push(self.consume(TokenType::Identifier, "expected variant name")?);
-        }
-
-        self.consume(TokenType::Dedent, "expected dedent after enum variants")?;
-
-        Ok(Stmt::Enum { name, variants })
-    }
-
     fn const_declaration(&mut self) -> Result<Stmt, ZernError> {
         let name = self.consume(TokenType::Identifier, "expected const name")?;
         self.consume(TokenType::Equal, "expected '=' after const name")?;

src/symbol_table.rs

@@ -75,8 +75,6 @@ impl SymbolTable {
                 }
                 let mut value = if value.lexeme.starts_with("0x") {
                     u64::from_str_radix(&value.lexeme[2..], 16).unwrap()
-                } else if value.lexeme.starts_with("0o") {
-                    u64::from_str_radix(&value.lexeme[2..], 8).unwrap()
                 } else {
                     value.lexeme.parse().unwrap()
                 } as i64;
@@ -146,16 +144,6 @@ impl SymbolTable {
 
                 self.structs.insert(name.lexeme.clone(), fields_map);
             }
-            Stmt::Enum { name, variants } => {
-                // TODO: distinct enum types
-                for (i, v) in variants.iter().enumerate() {
-                    let variant = format!("{}.{}", name.lexeme, v.lexeme);
-                    if self.is_name_defined(&variant) {
-                        return error!(name.loc, format!("tried to redefine '{}'", variant));
-                    }
-                    self.constants.insert(variant, i as i64);
-                }
-            }
             _ => {}
         }
         Ok(())

src/tokenizer.rs

@@ -58,7 +58,6 @@ pub enum TokenType {
     KeywordStruct,
     KeywordNew,
     KeywordAs,
-    KeywordEnum,
 
     Indent,
     Dedent,
@@ -345,10 +344,6 @@ impl Tokenizer {
             while self.peek().is_ascii_hexdigit() {
                 self.advance();
             }
-        } else if self.match_char('o') {
-            while matches!(self.peek(), '0'..='7') {
-                self.advance();
-            }
         } else {
             while self.peek().is_ascii_digit() {
                 self.advance();
@@ -399,7 +394,6 @@ impl Tokenizer {
             "struct" => TokenType::KeywordStruct,
             "new" => TokenType::KeywordNew,
             "as" => TokenType::KeywordAs,
-            "enum" => TokenType::KeywordEnum,
             "true" => TokenType::True,
             "false" => TokenType::False,
             _ => TokenType::Identifier,
@@ -412,7 +406,7 @@ impl Tokenizer {
         }
 
         if self.peek() != '"' {
-            return error!(self.loc, "expected '#' after 'include '");
+            return error!(self.loc, "expected '\"' after 'include '");
         }
         self.advance();
 
@@ -422,7 +416,7 @@ impl Tokenizer {
         }
 
         if self.eof() {
-            return error!(self.loc, "unterminated string after 'include'");
+            return error!(self.loc, "unterminated string after 'include '");
         }
 
         let path: String = self.source[path_start..self.current].iter().collect();

src/typechecker.rs

@@ -361,7 +361,6 @@ impl<'a> TypeChecker<'a> {
                     }
                 }
             }
-            Stmt::Enum { .. } => {}
         }
         Ok(())
     }

std/linux.zr

@@ -1,28 +1,4 @@
-const STDIN         = 0
+include "std/posix.zr"
-const STDOUT        = 1
-
-const SIGABRT       = 6
-
-const AT_FDCWD      = -100
-
-const S_IFDIR       = 0o040000
-const S_IFMT        = 0o170000
-
-const PROT_READ     = 1
-const PROT_WRITE    = 2
-
-const MAP_PRIVATE   = 2
-const MAP_ANONYMOUS = 32
-
-const O_RDONLY      = 0
-const O_WRONLY      = 1
-const O_CREAT       = 64
-const O_TRUNC       = 512
-
-const SEEK_SET      = 0
-const SEEK_END      = 2
-
-const F_OK          = 0
 
 const SYS_read                    =  0
 const SYS_write                   =  1

std/posix.zr

@@ -0,0 +1,27 @@
+const STDIN_FILENO   = 0
+const STDOUT_FILENO  = 1
+
+const SIGABRT        = 6
+
+const AT_FDCWD       = -100
+
+const S_IFDIR        = 16384
+const S_IFMT         = 61440
+
+const PROT_READ      = 1
+const PROT_WRITE     = 2
+
+const MAP_PRIVATE    = 2
+const MAP_ANONYMOUS  = 32
+
+const O_RDONLY       = 0
+const O_WRONLY       = 1
+const O_CREAT        = 64
+const O_TRUNC        = 512
+
+const SEEK_SET       = 0
+const SEEK_END       = 2
+
+const F_OK           = 0
+
+const CLOCK_REALTIME = 0

std/std.zr

@@ -1,4 +1,4 @@
-include "std/linux_constants.zr"
+include "std/linux.zr"
 
 func panic[msg: str] : void
     io.print("PANIC: ")
@@ -265,7 +265,7 @@ func io.printf[..] : void
         s += 1
 
 func io.print_sized[x: ptr, size: i64] : void
-    _builtin_syscall(SYS_write, STDOUT, x, size)
+    _builtin_syscall(SYS_write, STDOUT_FILENO, x, size)
 
 func io.print[x: str] : void
     io.print_sized(x as ptr, x->len())
@@ -381,7 +381,7 @@ func f64.to_str_buf[x: i64, buf: ptr] : void
 
 func io.read_char[] : u8
     c := 0 as u8
-    _builtin_syscall(SYS_read, STDIN, ^c, 1)
+    _builtin_syscall(SYS_read, STDIN_FILENO, ^c, 1)
     return c
 
 func io.read_line[] : str
@@ -438,7 +438,7 @@ func io.write_file[path: str, content: str] : bool
     return io.write_binary_file(path, content as ptr, content->len())
 
 func io.write_binary_file[path: str, content: ptr, size: i64] : bool
-    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_WRONLY|O_CREAT|O_TRUNC, 0o644)
+    fd := _builtin_syscall(SYS_openat, AT_FDCWD, path, O_WRONLY|O_CREAT|O_TRUNC, math.octal_to_decimal(644))
     if fd < 0
         return false
 
@@ -901,6 +901,17 @@ func math.pow[b: i64, e: i64] : i64
 func math.lcm[a: i64, b: i64] : i64
     return (a / math.gcd(a, b)) * b
 
+func math.octal_to_decimal[octal: i64] : i64
+    decimal := 0
+    base := 1
+
+    while octal > 0
+        digit := octal % 10
+        decimal += digit * base
+        base = base * 8
+        octal = octal / 10
+    return decimal
+
 struct Blob
     data: ptr
     size: i64
@@ -1146,6 +1157,12 @@ func os.sleep[ms: i64] : void
     req->tv_nsec = (ms % 1000) * 1000000
     _builtin_syscall(SYS_nanosleep, req, 0)
 
+func os.time[] : i64
+    ts := new os.Timespec
+    _builtin_syscall(SYS_clock_gettime, CLOCK_REALTIME, ts)
+    out := ts->tv_sec * 1000 + ts->tv_nsec / 1000000
+    return out
+
 func os.urandom_buf[buf: ptr, n: i64] : void
     pos := 0
     while pos < n
@@ -1164,16 +1181,6 @@ func os.urandom_i64[] : i64
     os.urandom_buf(^n, 8)
     return n
 
-struct os.Timeval
-    tv_sec: i64
-    tv_usec: i64
-
-func os.time[] : i64
-    tv := new os.Timeval
-    _builtin_syscall(SYS_gettimeofday, tv, 0)
-    out := tv->tv_sec * 1000 + tv->tv_usec / 1000
-    return out
-
 func os.run_shell_command[command: str] : i64, bool
     pid := _builtin_syscall(SYS_fork)
     if pid < 0