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Fixed problem with AST.

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This commit is contained in:
yhirose 2015-08-04 11:27:37 -04:00
parent de1f7ebad6
commit aa78055654
4 changed files with 106 additions and 150 deletions
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2
example/calc3.cc
View File

@ -55,7 +55,7 @@ int main(int argc, const char** argv)
shared_ptr<Ast> ast;
if (parser.parse(expr, ast)) {
ast = AstOptimizer(true).optimize(ast);
ast->print();
AstPrint::print(ast);
cout << expr << " = " << eval(*ast) << endl;
return 0;
}

201
example/pl0.cc
View File

@ -78,11 +78,11 @@ bool read_file(const char* path, vector<char>& buff)
/*
* Ast
*/
struct Scope;
struct SymbolScope;
struct Annotation
{
shared_ptr<Scope> scope;
shared_ptr<SymbolScope> scope;
};
typedef AstBase<Annotation> AstPL0;
@ -90,142 +90,124 @@ typedef AstBase<Annotation> AstPL0;
/*
* Symbol Table
*/
struct Symbol {
int value;
bool is_constant;
};
struct Scope
struct SymbolScope
{
Scope(shared_ptr<Scope> outer = nullptr) : outer(outer) {}
SymbolScope(shared_ptr<SymbolScope> outer) : outer(outer) {}
bool has_symbol(const string& ident) const {
auto it = symbols.find(ident);
if (it != symbols.end()) {
return true;
}
return outer ? outer->has_symbol(ident) : false;
auto ret = constants.find(ident) != constants.end() || variables.find(ident) != variables.end();
return ret ? true : (outer ? outer->has_symbol(ident) : false);
}
bool has_constant(const string& ident) const {
auto it = symbols.find(ident);
if (it != symbols.end() && it->second.is_constant) {
return true;
}
return outer ? outer->has_constant(ident) : false;
auto ret = constants.find(ident) != constants.end();
return ret ? true : (outer ? outer->has_constant(ident) : false);
}
bool has_variable(const string& ident) const {
auto it = symbols.find(ident);
if (it != symbols.end() && !it->second.is_constant) {
return true;
}
return outer ? outer->has_variable(ident) : false;
auto ret = variables.find(ident) != variables.end();
return ret ? true : (outer ? outer->has_variable(ident) : false);
}
bool has_procedure(const string& ident) const {
auto it = procedures.find(ident);
if (it != procedures.end()) {
return true;
}
return outer ? outer->has_procedure(ident) : false;
auto ret = procedures.find(ident) != procedures.end();
return ret ? true : (outer ? outer->has_procedure(ident) : false);
}
shared_ptr<AstPL0> get_procedure(const string& ident) const {
auto it = procedures.find(ident);
if (it != procedures.end()) {
return it->second;
}
return outer->get_procedure(ident);
}
map<string, Symbol> symbols;
map<string, int> constants;
set<string> variables;
map<string, shared_ptr<AstPL0>> procedures;
private:
shared_ptr<Scope> outer;
shared_ptr<SymbolScope> outer;
};
void throw_runtime_error(const shared_ptr<AstPL0> node, const string& msg) {
throw runtime_error(format_error_message(node->path, node->line, node->column, msg));
}
struct SymbolTable
{
static void build(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope = nullptr) {
static void build_on_ast(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope = nullptr) {
switch (ast->tag) {
case "block"_: visit_block(ast, scope); break;
case "assignment"_: visit_assignment(ast, scope); break;
case "call"_: visit_call(ast, scope); break;
case "ident"_: visit_ident(ast, scope); break;
default: for (auto node: ast->nodes) { build(node, scope); } break;
case "block"_: block(ast, scope); break;
case "assignment"_: assignment(ast, scope); break;
case "call"_: call(ast, scope); break;
case "ident"_: ident(ast, scope); break;
default: for (auto node: ast->nodes) { build_on_ast(node, scope); } break;
}
}
private:
static void visit_block(const shared_ptr<AstPL0> ast, shared_ptr<Scope> outer) {
static void block(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> outer) {
// block <- const var procedure statement
auto scope = make_shared<Scope>(outer);
auto scope = make_shared<SymbolScope>(outer);
const auto& nodes = ast->nodes;
visit_constants(nodes[0], scope);
visit_variables(nodes[1], scope);
visit_procedures(nodes[2], scope);
build(nodes[3], scope);
constants(nodes[0], scope);
variables(nodes[1], scope);
procedures(nodes[2], scope);
build_on_ast(nodes[3], scope);
ast->scope = scope;
}
static void visit_constants(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void constants(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
// const <- ('CONST' _ ident '=' _ number(',' _ ident '=' _ number)* ';' _) ?
const auto& nodes = ast->nodes;
for (auto i = 0u; i < nodes.size(); i += 2) {
const auto& ident = nodes[i + 0]->token;
if (scope->has_symbol(ident)) {
throw_runtime_error(nodes[i], "'" + ident + "' is already defined...");
}
auto number = stoi(nodes[i + 1]->token);
scope->symbols.emplace(ident, Symbol{ number, true });
scope->constants.emplace(ident, number);
}
}
static void visit_variables(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void variables(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
// var <- ('VAR' _ ident(',' _ ident)* ';' _) ?
const auto& nodes = ast->nodes;
for (auto i = 0u; i < nodes.size(); i += 1) {
const auto& ident = nodes[i]->token;
scope->symbols.emplace(ident, Symbol{ 0, false });
if (scope->has_symbol(ident)) {
throw_runtime_error(nodes[i], "'" + ident + "' is already defined...");
}
scope->variables.emplace(ident);
}
}
static void visit_procedures(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void procedures(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
// procedure <- ('PROCEDURE' _ ident ';' _ block ';' _)*
const auto& nodes = ast->nodes;
for (auto i = 0u; i < nodes.size(); i += 2) {
const auto& ident = nodes[i + 0]->token;
auto block = nodes[i + 1];
scope->procedures[ident] = block;
build(block, scope);
build_on_ast(block, scope);
}
}
static void visit_assignment(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void assignment(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
// assignment <- ident ':=' _ expression
const auto& ident = ast->nodes[0]->token;
if (!scope->has_variable(ident)) {
string msg = "undefined variable '" + ident + "'...";
string s = format_error_message(ast->path, ast->line, ast->column, msg);
throw runtime_error(s);
if (scope->has_constant(ident)) {
throw_runtime_error(ast->nodes[0], "cannot modify constant value '" + ident + "'...");
} else if (!scope->has_variable(ident)) {
throw_runtime_error(ast->nodes[0], "undefined variable '" + ident + "'...");
}
}
static void visit_call(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void call(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
// call <- 'CALL' _ ident
const auto& ident = ast->nodes[0]->token;
if (!scope->has_procedure(ident)) {
string msg = "undefined procedure '" + ident + "'...";
string s = format_error_message(ast->path, ast->line, ast->column, msg);
throw runtime_error(s);
throw_runtime_error(ast->nodes[0], "undefined procedure '" + ident + "'...");
}
}
static void visit_ident(const shared_ptr<AstPL0> ast, shared_ptr<Scope> scope) {
static void ident(const shared_ptr<AstPL0> ast, shared_ptr<SymbolScope> scope) {
const auto& ident = ast->token;
if (!scope->has_symbol(ident)) {
string msg = "undefined variable '" + ident + "'...";
string s = format_error_message(ast->path, ast->line, ast->column, msg);
throw runtime_error(s);
throw_runtime_error(ast, "undefined variable '" + ident + "'...");
}
}
};
@ -235,33 +217,36 @@ private:
*/
struct Environment
{
Environment(shared_ptr<Scope> scope = nullptr, shared_ptr<Environment> outer = nullptr) : scope(scope), outer(outer) {
if (scope) {
symbols = scope->symbols;
}
}
Environment(shared_ptr<SymbolScope> scope, shared_ptr<Environment> outer)
: scope(scope), outer(outer) {}
int get_value(const string& ident) const {
auto it = symbols.find(ident);
if (it != symbols.end()) {
return it->second.value;
auto it = scope->constants.find(ident);
if (it != scope->constants.end()) {
return it->second;
} else if (scope->variables.find(ident) != scope->variables.end()) {
return variables.at(ident);
}
return outer->get_value(ident);
}
void set_variable(const string& ident, int val) {
auto it = symbols.find(ident);
if (it != symbols.end() && !it->second.is_constant) {
symbols[ident].value = val;
if (scope->variables.find(ident) != scope->variables.end()) {
variables[ident] = val;
} else {
outer->set_variable(ident, val);
}
}
shared_ptr<Scope> scope;
shared_ptr<AstPL0> get_procedure(const string& ident) const {
auto it = scope->procedures.find(ident);
return it != scope->procedures.end() ? it->second : outer->get_procedure(ident);
}
shared_ptr<SymbolScope> scope;
private:
map<string, Symbol> symbols;
map<string, int> variables;
shared_ptr<Environment> outer;
};
@ -270,7 +255,7 @@ private:
*/
struct Interpreter
{
static void exec(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
static void exec(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env = nullptr) {
switch (ast->tag) {
case "block"_: exec_block(ast, env); break;
case "statement"_: exec_statement(ast, env); break;
@ -288,8 +273,7 @@ struct Interpreter
private:
static void exec_block(const shared_ptr<AstPL0> ast, shared_ptr<Environment> outer) {
// block <- const var procedure statement
auto env = make_shared<Environment>(ast->scope, outer);
exec(ast->nodes[3], env);
exec(ast->nodes[3], make_shared<Environment>(ast->scope, outer));
}
static void exec_statement(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
@ -301,17 +285,12 @@ private:
static void exec_assignment(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// assignment <- ident ':=' _ expression
const auto& ident = ast->nodes[0]->token;
auto expr = ast->nodes[1];
auto val = eval(expr, env);
env->set_variable(ident, val);
env->set_variable(ast->nodes[0]->token, eval(ast->nodes[1], env));
}
static void exec_call(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// call <- 'CALL' _ ident
const auto& ident = ast->nodes[0]->token;
auto proc = env->scope->get_procedure(ident);
exec_block(proc, env);
exec_block(env->get_procedure(ast->nodes[0]->token), env);
}
static void exec_statements(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
@ -323,10 +302,8 @@ private:
static void exec_if(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// if <- 'IF' _ condition 'THEN' _ statement
auto cond = eval_condition(ast->nodes[0], env);
if (cond) {
auto stmt = ast->nodes[1];
exec(stmt, env);
if (eval_condition(ast->nodes[0], env)) {
exec(ast->nodes[1], env);
}
}
@ -334,25 +311,21 @@ private:
// while <- 'WHILE' _ condition 'DO' _ statement
auto cond = ast->nodes[0];
auto stmt = ast->nodes[1];
auto ret = eval_condition(cond, env);
while (ret) {
while (eval_condition(cond, env)) {
exec(stmt, env);
ret = eval_condition(cond, env);
}
}
static void exec_out(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// out <- '!' _ expression
auto val = eval(ast->nodes[0], env);
cout << val << endl;
cout << eval(ast->nodes[0], env) << endl;
}
static void exec_in(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// in <- '?' _ ident
int val;
cin >> val;
const auto& ident = ast->nodes[0]->token;
env->set_variable(ident, val);
env->set_variable(ast->nodes[0]->token, val);
}
static bool eval_condition(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
@ -367,8 +340,7 @@ private:
static bool eval_odd(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
// odd <- 'ODD' _ expression
auto val = eval_expression(ast->nodes[0], env);
return val != 0;
return eval_expression(ast->nodes[0], env) != 0;
}
static bool eval_compare(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
@ -427,8 +399,7 @@ private:
break;
case '/':
if (rval == 0) {
string msg = "divide by 0 error";
throw runtime_error(format_error_message(ast->path, ast->line, ast->column, msg));
throw_runtime_error(ast, "divide by 0 error");
}
val = val / rval;
break;
@ -438,8 +409,7 @@ private:
}
static int eval_ident(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
const auto& ident = ast->token;
return env->get_value(ident);
return env->get_value(ast->token);
}
static int eval_number(const shared_ptr<AstPL0> ast, shared_ptr<Environment> env) {
@ -468,20 +438,19 @@ int main(int argc, const char** argv)
// Setup a PEG parser
peg parser(grammar);
parser.enable_ast<AstPL0>();
parser.log = [&](size_t ln, size_t col, const string& err_msg) {
cerr << format_error_message(path, ln, col, err_msg) << endl;
parser.log = [&](size_t ln, size_t col, const string& msg) {
cerr << format_error_message(path, ln, col, msg) << endl;
};
// Parse the source and make an AST
shared_ptr<AstPL0> ast;
if (parser.parse_n(source.data(), source.size(), ast, path)) {
if (argc > 2 && string("--ast") == argv[2]) {
ast->print();
AstPrint::print(ast);
}
try {
SymbolTable::build(ast);
Interpreter::exec(ast, make_shared<Environment>());
SymbolTable::build_on_ast(ast);
Interpreter::exec(ast);
} catch (const runtime_error& e) {
cerr << e.what() << endl;
}

2
lint/peglint.cc
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@ -97,7 +97,7 @@ int main(int argc, const char** argv)
}
ast = peglib::AstOptimizer(opt_optimize_ast_nodes).optimize(ast);
peglib::AstPrint().print(*ast);
peglib::AstPrint::print(ast);
} else {
if (!peg.parse_n(source.data(), source.size())) {
return -1;

49
peglib.h
View File

@ -1955,8 +1955,8 @@ inline constexpr unsigned int operator "" _(const char* s, size_t) {
}
#endif
template <typename MixedIn>
struct AstBase : public MixedIn
template <typename Annotation>
struct AstBase : public Annotation
{
AstBase(const char* path, size_t line, size_t column, const char* name, const std::vector<std::shared_ptr<AstBase>>& nodes)
: path(path ? path : "")
@ -2001,8 +2001,6 @@ struct AstBase : public MixedIn
, nodes(ast.nodes)
{}
void print() const;
const std::string path;
const size_t line;
const size_t column;
@ -2017,62 +2015,53 @@ struct AstBase : public MixedIn
const bool is_token;
const std::string token;
std::vector<std::shared_ptr<AstBase<MixedIn>>> nodes;
std::shared_ptr<AstBase<MixedIn>> parent_node;
std::vector<std::shared_ptr<AstBase<Annotation>>> nodes;
std::shared_ptr<AstBase<Annotation>> parent_node;
};
template <typename MixedIn>
struct AstPrintBase
struct AstPrint
{
AstPrintBase() : level_(-1) {}
void print(const AstBase<MixedIn>& ast) {
level_ += 1;
for (auto i = 0; i < level_; i++) { std::cout << " "; }
template <typename T>
static void print(const std::shared_ptr<T>& ptr, int level = 0) {
const auto& ast = *ptr;
for (auto i = 0; i < level; i++) { std::cout << " "; }
if (ast.is_token) {
std::cout << "- " << name(ast) << ": '" << ast.token << "'" << std::endl;
} else {
std::cout << "+ " << name(ast) << std::endl;
}
for (auto node : ast.nodes) { print(*node); }
level_ -= 1;
for (auto node : ast.nodes) { print(node, level + 1); }
}
private:
std::string name(const AstBase<MixedIn>& ast) {
template <typename T>
static std::string name(const T& ast) {
if (ast.name == ast.original_name) {
return ast.name;
} else {
return ast.original_name + " (" + ast.name + ")";
}
}
int level_;
};
template <typename MixedIn>
inline void AstBase<MixedIn>::print() const {
AstPrintBase<MixedIn>().print(*this);
}
template <typename MixedIn>
struct AstOptimizerBase
struct AstOptimizer
{
AstOptimizerBase(bool optimize_nodes, const std::vector<std::string>& filters = {})
AstOptimizer(bool optimize_nodes, const std::vector<std::string>& filters = {})
: optimize_nodes_(optimize_nodes)
, filters_(filters) {}
std::shared_ptr<AstBase<MixedIn>> optimize(std::shared_ptr<AstBase<MixedIn>> original, std::shared_ptr<AstBase<MixedIn>> parent = nullptr) {
template <typename T>
std::shared_ptr<T> optimize(std::shared_ptr<T> original, std::shared_ptr<T> parent = nullptr) {
auto found = std::find(filters_.begin(), filters_.end(), original->name) != filters_.end();
bool opt = optimize_nodes_ ? !found : found;
if (opt && original->nodes.size() == 1) {
auto child = optimize(original->nodes[0], parent);
return std::make_shared<AstBase<MixedIn>>(*child, original->name.c_str());
return std::make_shared<T>(*child, original->name.c_str());
}
auto ast = std::make_shared<AstBase<MixedIn>>(*original);
auto ast = std::make_shared<T>(*original);
ast->parent_node = parent;
ast->nodes.clear();
for (auto node : original->nodes) {
@ -2089,8 +2078,6 @@ private:
struct EmptyType {};
typedef AstBase<EmptyType> Ast;
typedef AstPrintBase<EmptyType> AstPrint;
typedef AstOptimizerBase<EmptyType> AstOptimizer;
/*-----------------------------------------------------------------------------
* peg