corelang/ccodegen.cpp

#define gen(...) pctx->gen.addf(__VA_ARGS__)
#define genln(...) do{gen("\n"); gen_indent(); gen(__VA_ARGS__); }while(0)
global S32 global_indent;
global S32 is_inside_struct;
global B32 should_gen_scope_name = false;

function void gen_ast(Ast *ast);
function bool gen_expr(Ast_Expr *ast, Ast_Type *type_of_var = 0);

function void
gen_indent(){
  for(S32 i = 0; i < global_indent; i++) gen("  ");
}

global Intern_String last_filename;
function void
gen_line(Ast *node){
  if(emit_line_directives){
    genln("#line %d", node->pos->line+1);
    if(node->pos->file != last_filename){
      last_filename = node->pos->file;
      gen(" \"%Q\"", last_filename);
    }
  }
}

function String
string_scope_name(Allocator *a, Ast_Scope *scope){
  String string = {};
  if(!should_gen_scope_name) return string;
  if(scope->parent_scope) string = string_scope_name(a, scope->parent_scope);
  if(scope->name.str) string = string_fmt(a, "%Q%Q_", string, scope->name);
  return string;
}

function void
gen_scope_name(Ast_Scope *scope){
  Scratch scratch;
  String string = string_scope_name(scratch, scope);
  gen("%.*s", (int)string.len, string.str);
}

function String
unique_name(Allocator *allocator, Ast *ast){
  Scratch scratch;
  B32 temp = should_gen_scope_name;
  should_gen_scope_name = true;
  String result = string_scope_name(scratch, ast->parent_scope);
  should_gen_scope_name = temp;
  assert(result.len);
  result = string_fmt(allocator, "%Q%d", result, ast->pos->line);
  return result;
}

// @todo: Gen complicated decl
//array 10 ( pointer (pointer array 5 int a))
// int (*(*(a[5])))[10]
//
// 1 Get to the bottom
// 2 Add variable name
// 3 Going backwards add arrays and pointers in parens
// 4 Add type name on the left side

function String
string_simple_decl_prefix(Allocator *a, Ast_Type *ast, bool scope_names){
  switch(ast->kind){
    case TYPE_POINTER:{
      String string = string_simple_decl_prefix(a, ast->base, scope_names);
      string = string_fmt(a, "%Q*", string);
      return string;
    }break;
    case TYPE_LAMBDA: return {}; break;
    case TYPE_ENUM:
    case TYPE_ARRAY: {
      return string_simple_decl_prefix(a, ast->base, scope_names);
    }break;
    case TYPE_SLICE:{
      String string = string_simple_decl_prefix(a, ast->base, true);
      string = string_fmt(a, "Slice%llu ", ast->type_id);
      return string;
    }break;
    case TYPE_TUPLE:{
      String string = string_fmt(a, "Tuple%llu ", ast->type_id);
      return string;
    }break;
    case TYPE_STRUCT: {
      auto constant = (Ast_Decl *)ast->ast;
      auto name = constant->name;
      String string = string_fmt(a, "%Q ", name);
      String sc = {};
      if(scope_names) sc = string_scope_name(a, constant->parent_scope);
      return string_fmt(a, "%Q%Q", sc, string);
    }break;
    default: {
      String string = string_fmt(a, "%s ", name(ast));
      return string;
    }
  }
  return {};
}

function String
string_simple_decl_postfix(Allocator *a, Ast_Type *ast, bool scope_names){
  switch(ast->kind){
    case TYPE_POINTER:
      return string_simple_decl_postfix(a, ast->base, scope_names);
      break;
    case TYPE_ARRAY:{
      String result = string_simple_decl_postfix(a, ast->arr.base, scope_names);
      String string = string_fmt(a, "[%d]%Q", ast->arr.size, result);
      return string;
    }break;
    case TYPE_LAMBDA:break;
    case TYPE_SLICE: case TYPE_ENUM: case TYPE_STRUCT:break;
    default:break;
    // default: return string_from_cstring((char *)name(ast));
  }
  return {};
}

function String
string_simple_decl(Allocator *a, Ast_Type *ast, Intern_String name = {}, Ast_Scope *scope = 0, bool scope_names = true){
  if(ast->kind == TYPE_LAMBDA) {
    String prefix = string_simple_decl_prefix(a, ast->func.ret, scope_names);
    String string = string_fmt(a, "%Q(*%Q)(", prefix, name);
    For(ast->func.args){
      String prefix_arg = string_simple_decl_prefix(a, it, scope_names);
      string = string_fmt(a, "%Q%Q", string, prefix_arg);
      if(&it != ast->func.args.end() - 1)
        string = string_fmt(a, "%Q, ", string);
    }
    string = string_fmt(a, "%Q)", string);
    return string;
  }
  else{
    String string = string_simple_decl_prefix(a, ast, scope_names);
    if(name.len) {
      if(scope && scope_names)
        string = string_fmt(a, "%Q%Q", string, string_scope_name(a, scope));
      string = string_fmt(a, "%Q%Q", string, name);
    }
    String postfix = string_simple_decl_postfix(a, ast, scope_names);
    string = string_fmt(a, "%Q%Q", string, postfix);
    return string;
  }
}

function void
gen_simple_decl(Ast_Type *ast, Intern_String name = {}, Ast_Scope *scope = 0, bool scope_names = true){
  Scratch scratch;
  String string = string_simple_decl(scratch, ast, name, scope, scope_names);
  gen("%.*s", (int)string.len, string.str);
}

function String
gen_string_simple_decl(Allocator *a, Ast_Type *ast, String name, Ast_Scope *scope, bool scope_names){
  Scratch scratch;
  String string = string_simple_decl(scratch, ast, pctx->intern(name), scope, scope_names);
  String result = string_copy(a, string);
  return result;
}

function B32
gen_value(Value a){
  B32 result = true;
  if(is_enum(a.type))
    goto integer;
  switch(a.type->kind){
    CASE_INT: {
      integer:
      Scratch scratch;
      const char *string = bigint_to_error_string(scratch, &a.big_int_val, 10);
      gen("%s", string);
    }break;
    CASE_STRING:
      if(is_pointer(a.type)){
        assert(a.type == type_pointer_to_char);
        gen("\"%Q\"", a.intern_val);
      } else{
        gen("LIT(\"%Q\")", a.intern_val);
      }
    break;
    CASE_BOOL: a.bool_val ? gen("true"):gen("false"); break;
    CASE_FLOAT: gen("%f", a.f64_val); break;
    default: result = false;
  }
  return result;
}

function void
gen_stmt_scope(Ast_Scope *scope){
  gen("{");
  global_indent++;
  For(scope->stmts) {
    gen_line(it);
    genln("");
    gen_ast(it);
  }
  global_indent--;
  genln("}");
}

enum {
  ALWAYS_EMIT_VALUE = 0,
  DONT_EMIT_VALUE = 1,
};

function void
gen_var(Ast_Decl *decl, B32 emit_value, B32 scope_names){
  gen_simple_decl(decl->type, decl->name, decl->parent_scope, scope_names);

  if(emit_value == DONT_EMIT_VALUE){
    return;
  }

  if(decl->expr){
    gen(" = ");
    gen_expr(decl->expr, decl->type);
  } else { // Default zero
    if(is_numeric(decl->type)){
      gen(" = 0");
    } else {
      gen(" = {}");
    }
  }
}

function void
gen_lambda(Intern_String name, Ast_Lambda *lambda, B32 generate_block = true){
  bool is_foreign = is_flag_set(lambda->flags, AST_FOREIGN);
  if(name == pctx->intern("main"_s) || name == pctx->intern("WinMain"_s)){
    is_foreign = true;
  }
  gen_simple_decl(lambda->resolved_type->func.ret, name, lambda->parent_scope, !is_foreign);
  gen("(");
  For(lambda->args){
    gen_var(it, DONT_EMIT_VALUE, true);
    if(&it != (lambda->args.end() - 1))
      gen(", ");
  }
  gen(")");

  if(generate_block && lambda->scope){
    gen_stmt_scope(lambda->scope);
  }
  else gen(";");
}

function bool
gen_expr(Ast_Expr *ast, Ast_Type *type_of_var){
  switch(ast->kind){
    CASE(IDENT, Atom){
      if(node->resolved_decl->kind == AST_MODULE_NAMESPACE || node->resolved_decl->kind == AST_FILE_NAMESPACE)
        return false;
      B32 print_scope = true;
      if(node->resolved_decl->lambda){
        if(is_flag_set(node->resolved_decl->lambda->flags, AST_FOREIGN))
          print_scope = false;
      }
      if(type_of_var && is_slice(type_of_var) && is_array(node->resolved_decl->type)){
        gen("{%d, ", (int)node->resolved_decl->type->arr.size);
        if(print_scope) gen_scope_name(node->resolved_decl->parent_scope);
        gen("%Q}", node->intern_val);
      } else {
        if(print_scope) gen_scope_name(node->resolved_decl->parent_scope);
        gen("%Q", node->intern_val);
      }
      BREAK();
    }

    CASE(VALUE, Atom){
      B32 written = gen_value(node->value);
      if(!written) {
        gen_scope_name(node->parent_scope);
        gen("%Q", node->value.intern_val);
      }
      BREAK();
    }

    CASE(INDEX, Index){
      gen("(");
      gen_expr(node->expr);
      if(is_string(node->resolved_type))
        if(!(type_of_var && type_of_var == type_pointer_to_char))
          gen(".str");
      gen("[");
      gen_expr(node->index);
      gen("]");
      gen(")");
      BREAK();
    }

    CASE(LAMBDA_EXPR, Lambda){
      gen_lambda({}, node);
      BREAK();
    }

    CASE(BINARY, Binary){
      if(node->op == TK_Dot){
        if(gen_expr(node->left)){
          if(node->resolved_type && node->resolved_type->kind == TYPE_POINTER) gen("->");
          else gen(".");
        }
        gen_expr(node->right);
        return true;
      }
      else if(node->op == TK_Arrow){
        gen("(");
        gen("(");
        gen_simple_decl(node->resolved_type);
        gen(")");
        gen_expr(node->left);
        gen(")");
        return true;
      }

      if(!token_is_assign(node->op)) gen("(");
      gen_expr(node->left);
      gen("%s", name(node->op));
      gen_expr(node->right);
      if(!token_is_assign(node->op)) gen(")");

      BREAK();
    }

    CASE(UNARY, Unary){
      gen("(");
      if(node->op != TK_PostIncrement && node->op != TK_PostDecrement) gen("%s", name(node->op));
      gen_expr(node->expr);
      if(node->op == TK_PostIncrement || node->op == TK_PostDecrement) gen("%s", name(node->op));
      gen(")");
      BREAK();
    }

    CASE(VAR, Decl){
      gen_ast(node);
      BREAK();
    }

    CASE(LENGTH_OF, Builtin){
      gen_expr(node->expr);
      if(is_pointer(node->expr->resolved_type))
        gen("->len");
      else gen(".len");
      BREAK();
    }

    CASE(CALL, Call){
      gen_expr(node->name);
      gen("(");
      For(node->exprs){
        gen_expr(it->item);
        if(!node->exprs.is_last(&it)) gen(", ");
      }
      gen(")");
      BREAK();
    }

    CASE(COMPOUND, Call){
      gen("(");
      gen_simple_decl(node->resolved_type);
      gen(")");
      gen("{");

      For(node->exprs){
        if(is_struct(node->resolved_type))
          gen(".%Q = ", it->resolved_name);
        else if(is_array(node->resolved_type))
          gen("[%d] = ", (int)it->resolved_index);
        gen_expr(it->item);
        if(!node->exprs.is_last(&it)) gen(", ");
      }
      gen("}");
      BREAK();
    }

    invalid_default_case;
  }
  return true;
}

function void
gen_ast(Ast *ast){
  switch(ast->kind){

    CASE(RUNTIME_ASSERT, Builtin){
      if(node->assert_message.len == 0) gen("assert");
      else                              gen("assert_msg");
      gen("(");
      gen_expr(node->expr);
      if(node->assert_message.len){
        gen(", \"%Q\"", node->assert_message);
      }
      gen(");");
      BREAK();
    }

    CASE(RETURN, Return){
      if(is_tuple(node->resolved_type)) {
        Scratch scratch;
        Intern_String var_name = pctx->intern(unique_name(scratch, node));
        gen_simple_decl(node->resolved_type, var_name);
        gen(";");

        int i = 0;
        For(node->expr){
          genln("memcpy(&%Q.m%d, ", var_name, i);
          if(!is_array(it->resolved_type)) gen("&");
          gen("(");
          gen_expr(it);
          gen(")");
          gen(", sizeof(%Q.m%d));", var_name, i++);
        }

        genln("return %Q;", var_name);
        return;
      }

      assert(node->expr.len <= 1);
      gen("return ");
      For(node->expr) gen_expr(it);
      gen(";");
      BREAK();
    }

    CASE(VAR, Decl){
      gen_var(node, is_inside_struct ? DONT_EMIT_VALUE : ALWAYS_EMIT_VALUE, true);
      if(!is_flag_set(ast->flags, AST_EXPR)) gen(";");
      BREAK();
    }

    CASE(IF, If){
      For(node->ifs){
        if(it->init) {
          gen_expr(it->init);
          gen(";");
          genln("");
        }
        if(node->ifs.is_first(&it)){
          gen("if(");
          gen_expr(it->expr);
          gen(")");
          gen_stmt_scope(it->scope);
        }
        else{
          genln("else");
          if(it->expr){
            gen(" if(");
            gen_expr(it->expr);
            gen(")");
          }
          gen_stmt_scope(it->scope);
        }
      }
      BREAK();
    }


    CASE(BREAK, Break){
      unused(node);
      gen("break;");
      BREAK();
    }


    CASE(PASS, Pass){
      unused(node);
      gen("//pass");
      BREAK();
    }

    CASE(BINARY,Binary){
      gen_expr(node);
      gen(";");
      BREAK();
    }

    CASE(FOR, For){
      gen("for(");
      if(node->init) gen_expr(node->init);
      gen(";");
      if(node->cond) gen_expr(node->cond);
      gen(";");
      if(node->iter) gen_expr(node->iter);
      gen(")");
      gen_stmt_scope(node->scope);
      BREAK();
    }

    CASE(LAMBDA, Decl){
      gen_line(node);
      genln("");
      if(is_flag_set(node->expr->flags, AST_FOREIGN)){
        gen("/*foreign*/");
      }
      gen_lambda(node->name, node->lambda);
      BREAK();
    }

    CASE(STRUCT, Decl){
      gen("struct ");
      gen_scope_name(node->parent_scope);
      gen("%Q{", node->name);
      global_indent++;
      is_inside_struct++;
      For(node->scope->decls){
        genln("");
        gen_ast(it);
      }

      is_inside_struct--;
      global_indent--;
      genln("};");
      BREAK();
    }

    CASE(TYPE, Decl){
      gen("// Type %Q = ", node->name);
      gen_simple_decl(node->type_val);
      BREAK();
    }

    CASE(ENUM, Decl){
      gen("/*enum %Q{", node->name);
      // @todo add typespec
      global_indent++;
      For(node->scope->decls){
        genln("%Q", it->name);
        gen(" = ");
        gen_value(it->value);
        gen(",");
      }
      global_indent--;
      genln("};*/");
      BREAK();
    }

    CASE(CONST, Decl){
      switch(node->type->kind){
        CASE_FLOAT:{
          gen("// F64 %Q = ", node->name);
          gen_value(node->value);
        } break;
        CASE_INT:{
          gen("// constant int %Q = ", node->name);
          gen_value(node->value);
        }break;
        CASE_STRING:{
          assert(is_pointer(node->type) ? node->type == type_pointer_to_char : 1);
          gen("// const String %Q = ", node->name);
          gen_value(node->value);
        }break;
        CASE_BOOL:{
          gen("// const Bool %Q = ", node->name);
          gen_value(node->value);
        }break;
        case TYPE_LAMBDA:{
          gen("// ");
          gen_lambda(node->name, node->lambda);
        } break;
        invalid_default_case;
      }

      BREAK();
    }

    CASE(VAR_UNPACK, Var_Unpack){
      For(node->vars)
        gen_ast(it);

      Scratch scratch;
      Intern_String var_name = pctx->intern(unique_name(scratch, node));
      gen_simple_decl(node->resolved_type, var_name);
      gen(" = ");
      gen_expr(node->expr);
      gen(";");

      int i = 0;
      For(node->vars){
        gen("memcpy((void *)&%Q, (void *)&%Q.m%d, sizeof(%Q));", it->name, var_name, i++, it->name);
      }
      BREAK();
    }

    case AST_CONSTANT_ASSERT:
    case AST_MODULE_NAMESPACE:
    CASE(FILE_NAMESPACE, File_Namespace){unused(node); BREAK();}

    default: {
      assert(is_flag_set(ast->flags, AST_EXPR));
      gen_expr((Ast_Expr *)ast);
      gen(";");
    }
  }
}

function void
parse_file(Ast_File *file){
  assert(file);

  Scratch scratch;
  file->filecontent = os_read_file(pctx->perm, file->filename.s);
  if(file->filecontent.len == 0){
    compiler_error(file->pos, "Failed to open file \"%Q\"", file->filename);
  }


  pctx->currently_parsed_file  = file;
  String name = string_chop_last_period(file->filename.s);
  file->name = pctx->intern(name);

  pctx->currently_parsed_scope = file;
  lex_restream(pctx, file->filecontent, file->filename.s);
  while(token_expect(SAME_SCOPE)){
    if(token_match_pound(pctx->intern("load"_s))){
      parse_load(true);
      continue;
    } else if(token_match_pound(pctx->intern("import"_s))){
      parse_import(true);
      continue;
    }

    Ast_Decl *decl = parse_decl(true);
    if(!decl) break;

    set_flag(decl->flags, AST_GLOBAL);
    if(decl->kind == AST_STRUCT){
      decl->type     = type_type;
      decl->type_val = type_incomplete(decl);
      decl->state    = DECL_RESOLVED;
    }

    insert_into_scope(file, decl);
  }
  pctx->currently_parsed_scope = 0;
  pctx->currently_parsed_file = 0;
}

function void
insert_builtin_into_scope(Ast_Scope *p, String name, Ast_Type *type){
  Intern_String string = pctx->intern(name);
  Ast_Decl *decl = ast_type(0, string, type);
  type->type_id = pctx->type_ids++;
  decl->parent_scope = p;
  decl->state = DECL_RESOLVED;
  insert_into_scope(p, decl);
}

function void
insert_builtin_types_into_scope(Ast_Scope *p){
  insert_builtin_into_scope(p, "void"_s  , type_void);
  insert_builtin_into_scope(p, "Bool"_s  , type_bool);
  insert_builtin_into_scope(p, "String"_s, type_string);
  insert_builtin_into_scope(p, "char"_s, type_char);
  insert_builtin_into_scope(p, "int"_s, type_int);
  insert_builtin_into_scope(p, "S8"_s, type_s8);
  insert_builtin_into_scope(p, "S16"_s, type_s16);
  insert_builtin_into_scope(p, "S32"_s, type_s32);
  insert_builtin_into_scope(p, "S64"_s, type_s64);
  insert_builtin_into_scope(p, "U8"_s, type_u8);
  insert_builtin_into_scope(p, "U16"_s, type_u16);
  insert_builtin_into_scope(p, "U32"_s, type_u32);
  insert_builtin_into_scope(p, "U64"_s, type_u64);
  insert_builtin_into_scope(p, "F32"_s, type_f32);
  insert_builtin_into_scope(p, "F64"_s, type_f64);
  insert_builtin_into_scope(p, "Any"_s, type_any);
}

global F64 parsing_time_begin;
global F64 parsing_time_end;
function void
parse_files(Ast_Module *module){
  for(S64 i = 0; i < module->all_loaded_files.len; i++){
    auto it = module->all_loaded_files.data[i];
    parse_file(it);
  }
}

function void
parse_all_modules(){
  parsing_time_begin = os_time();
  for(S64 i = 0; i < pctx->modules.len; i++){
    Ast_Module *it = pctx->modules[i];
    parse_files(it);
    it->implicit_imports.add(pctx->builtins);
  }
  parsing_time_end = os_time();
}

function Ast_Module *
add_module(Token *pos, Intern_String filename){
  For(pctx->modules){
    if(it->name == filename){
      log_info("Returning registered module: %Q\n", filename);
      return it;
    }
  }

  log_info("Adding module: %Q\n", filename);
  Ast_Module *result = ast_module(pos, filename);
  register_ast_file(pos, result->name, result, true);
  pctx->modules.add(result);
  return result;
}

global F64 resolving_time_begin;
global F64 resolving_time_end;
function void
resolve_everything_in_module(Ast_Module *module){
  resolving_time_begin = os_time();
  for(S64 i = 0; i < module->all_loaded_files.len; i++){
    Ast_File *it = module->all_loaded_files[i];
    For_Named(it->decls, jt){
      resolve_name(it, jt->pos, jt->name);
      if(jt->kind == AST_STRUCT){
        type_complete(jt->type_val);
      }
    }
  }
  resolving_time_end = os_time();
}

global F64 init_ctx_time_begin;
global F64 init_ctx_time_end;
function void
begin_compilation(){
  init_ctx_time_begin = os_time();
  OS_Heap *heap = exp_alloc_type(&pernament_arena, OS_Heap);
  *heap = win32_os_heap_create(false, mib(4), 0);
  Parse_Ctx *ctx = exp_alloc_type(&pernament_arena, Parse_Ctx);
  parse_init(ctx, &pernament_arena, heap);
  init_ctx_time_end = os_time();
}

global F64 generating_time_begin;
global F64 generating_time_end;
function String
get_compilation_result(){
  generating_time_begin = os_time();

#if 1
  gen(R"==(
#include <stdint.h>
#include <math.h>
#include <string.h>
typedef int8_t   S8;
typedef int16_t  S16;
typedef int32_t  S32;
typedef int64_t  S64;
typedef uint8_t  U8;
typedef uint16_t U16;
typedef uint32_t U32;
typedef uint64_t U64;
typedef S8       B8;
typedef S16      B16;
typedef S32      B32;
typedef S64      B64;
typedef U64      SizeU;
typedef S64      SizeS;
typedef float    F32;
typedef double   F64;
typedef S32     Bool;
#define true 1
#define false 0

typedef struct String{
  U8 *str;
  S64 len;
}String;
#define LIT(x) (String){.str=(U8 *)x, .len=sizeof(x)-1}
#define assert(x) do{if(!(x))__debugbreak();}while(0)
#define assert_msg(x,...) assert(x)

  )==");
  //*(volatile int *)0 = 0;
#endif
  For(pctx->ordered_decls){
    if(it->kind == AST_STRUCT){
      genln("typedef struct %Q %Q;", it->name, it->name);
    }
  }

  Scratch scratch;
  for(S64 i = 0; i < pctx->type_map.cap; i++){
    Map_Key_Value *it = pctx->type_map.data + i;
    if(!it->occupied) continue;
    Ast_Type *type = (Ast_Type *)it->value;

    if(type->kind == TYPE_SLICE){
      genln("typedef struct Slice%llu{", type->type_id);
      global_indent++;
        genln("S64 len;");
        genln("");
        gen_simple_decl(type->base);
        gen(" data;");
      global_indent--;
      genln("} Slice%llu;", type->type_id);
    }

    else if(type->kind == TYPE_TUPLE){
      genln("typedef struct Tuple%llu{", type->type_id);
      global_indent++;
      For(type->agg.members){
        genln("");
        // @todo remove intern from gen
        Intern_String name = pctx->intern(string_fmt(scratch, "m%llu", type->agg.members.get_index(&it)));
        gen_simple_decl(it.type, name);
        gen(";");
      }
      global_indent--;
      genln("} Tuple%llu;", type->type_id);
    }
  }


  For(pctx->ordered_decls){
    if(it->kind == AST_LAMBDA){
      genln("");
      gen_lambda(it->name, it->lambda, false);
    }
  }


  For(pctx->ordered_decls){
    genln("");
    gen_ast(it);
  }

  String string_result = string_flatten(pctx->perm, &pctx->gen);
  generating_time_end = os_time();
  return string_result;
}

function void
compiler_cleanup(){
  exp_destroy(pctx->heap);
}