Nasal-Interpreter/src/nasal_import.cpp

429 lines
13 KiB
C++

#include "nasal_import.h"
#include "symbol_finder.h"
#include "util/util.h"
#include "util/fs.h"
#include <memory>
#include <unordered_set>
namespace nasal {
linker::linker(): show_path_flag(false), this_file("") {
const auto env_get_path = getenv("PATH");
if (!env_get_path) {
err.warn("link", "cannot get env \"PATH\".");
envpath = {};
return;
}
const auto seperator = util::is_windows()? ';':':';
const auto PATH = std::string(env_get_path);
usize last = 0, position = PATH.find(seperator, 0);
while (position!=std::string::npos) {
std::string dirpath = PATH.substr(last, position-last);
if (dirpath.length()) {
envpath.push_back(dirpath);
}
last = position+1;
position = PATH.find(seperator, last);
}
if (last!=PATH.length()) {
envpath.push_back(PATH.substr(last));
}
}
std::string linker::get_path(expr* node) {
if (node->get_type()==expr_type::ast_use) {
auto file_relative_path = std::string("");
const auto& path = reinterpret_cast<use_stmt*>(node)->get_path();
for (auto i : path) {
file_relative_path += i->get_name();
if (i!=path.back()) {
file_relative_path += (util::is_windows()? "\\":"/");
}
}
return file_relative_path + ".nas";
}
auto call_node = reinterpret_cast<call_expr*>(node);
auto arguments = reinterpret_cast<call_function*>(call_node->get_calls()[0]);
auto content = reinterpret_cast<string_literal*>(arguments->get_argument()[0]);
return content->get_content();
}
std::string linker::find_real_file_path(const std::string& filename,
const span& location) {
// first add file name itself into the file path
std::vector<fs::path> path_list = {filename};
// generate search path from environ path
for (const auto& p : envpath) {
path_list.push_back(fs::path(p)/filename);
}
// search file
for (const auto& path : path_list) {
if (fs::exists(path)) {
return path.str();
}
}
// we will find lib.nas in nasal std directory
if (filename=="lib.nas") {
return util::is_windows()?
find_real_file_path("std\\lib.nas", location):
find_real_file_path("std/lib.nas", location);
}
if (!show_path_flag) {
err.err("link",
"in <" + location.file + ">: " +
"cannot find file <" + filename + ">, " +
"use <-d> to get detail search path"
);
return "";
}
auto path_list_info = std::string("");
for (const auto& path : path_list) {
path_list_info += " -> " + path.str() + "\n";
}
err.err("link",
"in <" + location.file + ">: " +
"cannot find file <" + filename +
"> in these paths:\n" + path_list_info
);
return "";
}
bool linker::import_check(expr* node) {
if (node->get_type()==expr_type::ast_use) {
return true;
}
/*
call
|_id:import
|_call_func
|_string:'filename'
*/
if (node->get_type()!=expr_type::ast_call) {
return false;
}
auto call_node = reinterpret_cast<call_expr*>(node);
auto first_expr = call_node->get_first();
if (first_expr->get_type()!=expr_type::ast_id) {
return false;
}
if (reinterpret_cast<identifier*>(first_expr)->get_name()!="import") {
return false;
}
if (!call_node->get_calls().size()) {
return false;
}
// import("xxx");
if (call_node->get_calls().size()!=1) {
return false;
}
auto maybe_func_call = call_node->get_calls()[0];
if (maybe_func_call->get_type()!=expr_type::ast_callf) {
return false;
}
auto func_call = reinterpret_cast<call_function*>(maybe_func_call);
if (func_call->get_argument().size()!=1) {
return false;
}
if (func_call->get_argument()[0]->get_type()!=expr_type::ast_str) {
return false;
}
return true;
}
bool linker::check_exist_or_record_file(const std::string& file) {
// avoid importing the same file
for (const auto& name : imported_files) {
if (file==name) {
return true;
}
}
imported_files.push_back(file);
return false;
}
bool linker::check_self_import(const std::string& file) {
for (const auto& name : module_load_stack) {
if (file==name) {
return true;
}
}
return false;
}
std::string linker::generate_self_import_path(const std::string& filename) {
std::string res = "";
for (const auto& i : module_load_stack) {
res += "[" + i + "] -> ";
}
return res + "[" + filename + "]";
}
void linker::merge_tree(code_block* new_tree_root, code_block* old_tree_root) {
// add children of add_root to the back of root
for (auto& i : old_tree_root->get_expressions()) {
new_tree_root->add_expression(i);
}
// clean old root
old_tree_root->get_expressions().clear();
}
code_block* linker::import_regular_file(
expr* node, std::unordered_set<std::string>& used_modules) {
// get filename
auto filename = get_path(node);
// avoid infinite loading loop
filename = find_real_file_path(filename, node->get_location());
// if get empty string(error) or this file is used before, do not parse
if (!filename.length() || used_modules.count(filename)) {
return new code_block({0, 0, 0, 0, filename});
}
// check self import, avoid infinite loading loop
if (check_self_import(filename)) {
err.err("link",
node->get_location(),
"self-referenced module <" + filename + ">, " +
"reference path: " + generate_self_import_path(filename)
);
return new code_block({0, 0, 0, 0, filename});
}
check_exist_or_record_file(filename);
module_load_stack.push_back(filename);
// avoid stack overflow
if (module_load_stack.size()>MAX_RECURSION_DEPTH) {
err.err("link",
node->get_location(),
"too deep module import stack (>" +
std::to_string(MAX_RECURSION_DEPTH) + ")."
);
return new code_block({0, 0, 0, 0, filename});
}
// start importing...
lexer nasal_lexer;
parse nasal_parser;
if (nasal_lexer.scan(filename).geterr()) {
err.err("link",
node->get_location(),
"error occurred when analysing <" + filename + ">"
);
return new code_block({0, 0, 0, 0, filename});
}
if (nasal_parser.compile(nasal_lexer).geterr()) {
err.err("link",
node->get_location(),
"error occurred when analysing <" + filename + ">"
);
return new code_block({0, 0, 0, 0, filename});
}
// swap result out
auto parse_result = nasal_parser.swap(nullptr);
// check if parse result has 'import'
load(parse_result, filename);
module_load_stack.pop_back();
return parse_result;
}
code_block* linker::import_nasal_lib() {
auto path = find_real_file_path(
"lib.nas", {0, 0, 0, 0, this_file}
);
if (!path.length()) {
return new code_block({0, 0, 0, 0, path});
}
// avoid infinite loading library
if (check_exist_or_record_file(path)) {
return new code_block({0, 0, 0, 0, path});
}
// start importing...
lexer nasal_lexer;
parse nasal_parser;
if (nasal_lexer.scan(path).geterr()) {
err.err("link",
"error occurred when analysing library <" + path + ">"
);
return new code_block({0, 0, 0, 0, path});
}
if (nasal_parser.compile(nasal_lexer).geterr()) {
err.err("link",
"error occurred when analysing library <" + path + ">"
);
return new code_block({0, 0, 0, 0, path});
}
// swap result out
auto parse_result = nasal_parser.swap(nullptr);
// check if library has 'import' (in fact it should not)
load(parse_result, path);
return parse_result;
}
std::string linker::generate_module_name(const std::string& file_path) {
// import("...") may trigger this error module name
auto error_name = "module@[" + file_path + "]";
if (!file_path.length()) {
return error_name;
}
// check file suffix and get file suffix position
auto suffix_position = file_path.find(".nas");
if (suffix_position==std::string::npos) {
err.warn("link",
"get invalid module name from <" + file_path + ">, " +
"will not be easily accessed. " +
"\".nas\" suffix is required."
);
return error_name;
}
if (suffix_position+4!=file_path.length()) {
err.warn("link",
"get invalid module name from <" + file_path + ">, " +
"will not be easily accessed. " +
"only one \".nas\" suffix is required in the path."
);
return error_name;
}
// only get the file name as module name, directory path is not included
auto split_position = file_path.find_last_of("/");
// find "\\" in windows platform
if (split_position==std::string::npos) {
split_position = file_path.find_last_of("\\");
}
// split file path to get module name
auto module_name = split_position==std::string::npos?
file_path.substr(0, suffix_position):
file_path.substr(split_position+1, suffix_position-split_position-1);
// check validation of module name
if (!module_name.length()) {
err.warn("link",
"get empty module name from <" + file_path + ">, " +
"will not be easily accessed."
);
return module_name;
}
if (std::isdigit(module_name[0]) ||
module_name.find(".")!=std::string::npos ||
module_name.find("-")!=std::string::npos) {
err.warn("link",
"get module <" + module_name + "> from <" + file_path + ">, " +
"will not be easily accessed."
);
}
return module_name;
}
return_expr* linker::generate_module_return(code_block* block) {
auto finder = std::make_unique<symbol_finder>();
auto result = new return_expr(block->get_location());
auto value = new hash_expr(block->get_location());
result->set_value(value);
for (const auto& i : finder->do_find(block)) {
// do not export symbol begins with '_'
if (i.name.length() && i.name[0]=='_') {
continue;
}
auto pair = new hash_pair(block->get_location());
pair->set_name(i.name);
pair->set_value(new identifier(block->get_location(), i.name));
value->add_member(pair);
}
return result;
}
definition_expr* linker::generate_module_definition(code_block* block) {
// generate ast node like this:
// var {module_name} = (func() {
// ... # module itself
// })();
auto def = new definition_expr(block->get_location());
def->set_identifier(new identifier(
block->get_location(),
generate_module_name(block->get_location().file)
));
// (func() {...})();
auto call = new call_expr(block->get_location());
// func() {...}
auto func = new function(block->get_location());
func->set_code_block(block);
func->get_code_block()->add_expression(generate_module_return(block));
call->set_first(func);
call->add_call(new call_function(block->get_location()));
def->set_value(call);
return def;
}
void linker::load(code_block* program_root, const std::string& filename) {
// load imported modules
std::unordered_set<std::string> used_modules = {};
for (auto& import_node : program_root->get_expressions()) {
if (!import_check(import_node)) {
break;
}
// parse file and get ast
auto module_code_block = import_regular_file(import_node, used_modules);
// avoid repeatedly importing the same module in one file
const auto& module_path = module_code_block->get_location().file;
if (used_modules.count(module_path)) {
delete module_code_block;
auto replace_node = new null_expr(import_node->get_location());
// after importing the regular file as module, delete this node
delete import_node;
// and replace the node with null_expr node
import_node = replace_node;
continue;
}
used_modules.insert(module_path);
delete import_node;
// then we generate a function warping the code block,
// and export the necessary global symbols in this code block
// by generate a return statement, with a hashmap return value
import_node = generate_module_definition(module_code_block);
}
}
const error& linker::link(parse& parse, bool spath = false) {
// switch for showing path when errors occur
show_path_flag = spath;
// initializing file map
this_file = parse.tree()->get_location().file;
imported_files = {this_file};
module_load_stack = {this_file};
// scan root and import files
// then generate a new ast and return to import_ast
// dfs load file
auto library = import_nasal_lib();
// load used modules of this file
load(parse.tree(), this_file);
// then insert the whole tree into library tree root
merge_tree(library, parse.tree());
// swap tree root, and delete old root
delete parse.swap(library);
if (imported_files.size()>=UINT16_MAX) {
err.err("link",
"too many imported files: " +
std::to_string(imported_files.size())
);
}
return err;
}
}