commit f4d34a86af992ecea9b4ea519c0891c696b46118
parent d49d9e9e2b49650abcd8318fe665965b2d7fef22
Author: Mohammad-Reza Nabipoor <m.nabipoor@yahoo.com>
Date: Sun, 30 Aug 2020 15:59:25 +0430
kaleidoscope_parser: Changed error reporting
Diffstat:
2 files changed, 103 insertions(+), 120 deletions(-)
diff --git a/kaleidoscope_parser.hpp b/kaleidoscope_parser.hpp
@@ -8,6 +8,13 @@
namespace kal {
+template<typename FwdIt>
+struct ParseError
+{
+ FwdIt pos;
+ std::string msg;
+};
+
namespace detail {
template<typename FwdIt>
@@ -15,57 +22,52 @@ struct ParseResult
{
FwdIt parsed; // position of successfully parsed token(s)
ASTNode node;
- struct
- {
- FwdIt pos; // position of the error
- std::string msg;
- } err;
};
-template<typename FwdIt>
+template<typename FwdIt, typename OutErrIt>
+ParseResult<FwdIt>
+parse_expr(FwdIt f, FwdIt l, OutErrIt error);
+
+template<typename FwdIt, typename OutErrIt>
ParseResult<FwdIt>
-parse_prototype(FwdIt f, FwdIt l)
+parse_expr_primary(FwdIt f, FwdIt l, OutErrIt error);
+
+template<typename FwdIt, typename OutErrIt>
+ParseResult<FwdIt>
+parse_prototype(FwdIt f, FwdIt l, OutErrIt error)
{
ParseResult<FwdIt> r{
f,
};
Prototype p;
auto err = [&](auto&& msg) {
- r.err.pos = f;
- r.err.msg = std::move(msg);
+ *error++ = ParseError<FwdIt>{ f, std::move(msg) };
+ return r;
};
assert(f != l);
- if (token_type(*f) != TkType::Id) {
- err("expects identifier");
- return r;
- }
+ if (token_type(*f) != TkType::Id)
+ return err("expects identifier");
p.name = token_str(*f);
++f;
- if (token_str(*f) != "(") {
- err("expects `(`");
- return r;
- }
+ if (token_str(*f) != "(")
+ return err("expects `(`");
++f;
// args
while (f != l && token_str(*f) != ")") {
- if (token_type(*f) != TkType::Id) {
- err("early termination: expects identifier");
- return r;
- }
+ if (token_type(*f) != TkType::Id)
+ return err("early termination: expects identifier");
p.params.emplace_back(token_str(*f));
++f;
}
- if (f == l) {
- err("early termination: expects `)`");
- return r;
- }
+ if (f == l)
+ return err("early termination: expects `)`");
++f;
r.parsed = f;
@@ -73,20 +75,16 @@ parse_prototype(FwdIt f, FwdIt l)
return r;
}
-template<typename FwdIt>
-ParseResult<FwdIt>
-parse_expr(FwdIt f, FwdIt l);
-
-template<typename FwdIt>
+template<typename FwdIt, typename OutErrIt>
ParseResult<FwdIt>
-parse_expr_idexpr(FwdIt f, FwdIt l)
+parse_expr_idexpr(FwdIt f, FwdIt l, OutErrIt error)
{
ParseResult<FwdIt> r{
f,
};
auto err = [&](auto&& msg) {
- r.err.pos = f;
- r.err.msg = std::move(msg);
+ *error++ = ParseError<FwdIt>{ f, std::move(msg) };
+ return r;
};
assert(f != l);
@@ -105,10 +103,8 @@ parse_expr_idexpr(FwdIt f, FwdIt l)
++f; // drop "("
while (true) {
- if (f == l) {
- err("early termination of call expression");
- return r;
- }
+ if (f == l)
+ return err("early termination of call expression");
if (token_str(*f) == ")") {
r.node = std::move(call);
@@ -117,15 +113,10 @@ parse_expr_idexpr(FwdIt f, FwdIt l)
}
{
- auto rpe = parse_expr(f, l);
+ auto rpe = parse_expr(f, l, error);
- if (rpe.parsed == f) {
- // FIXME error
- err("error in parsing call arguments: ");
- r.err.msg += rpe.err.msg + " (at relative pos " +
- std::to_string(std::distance(f, rpe.err.pos)) + ")";
- return r;
- }
+ if (rpe.parsed == f)
+ return err("error in parsing call arguments");
call.args.emplace_back(std::move(rpe.node));
f = rpe.parsed;
@@ -142,8 +133,7 @@ parse_expr_idexpr(FwdIt f, FwdIt l)
break;
default:
- err(std::string{ "expects ',' but got " } + kal::to_string(*f));
- return r;
+ return err("expects ','");
}
}
@@ -151,20 +141,20 @@ parse_expr_idexpr(FwdIt f, FwdIt l)
return r;
}
-template<typename FwdIt>
-ParseResult<FwdIt>
-parse_expr_primary(FwdIt f, FwdIt l);
-
-template<typename FwdIt>
+template<typename FwdIt, typename ErrOutIt>
ParseResult<FwdIt>
-parse_expr_binop_rhs(FwdIt f, FwdIt l, int precedence, ASTNode lhs)
+parse_expr_binop_rhs(FwdIt f,
+ FwdIt l,
+ int precedence,
+ ASTNode lhs,
+ ErrOutIt error)
{
ParseResult<FwdIt> r{
f,
};
auto err = [&](auto&& msg) {
- r.err.pos = f;
- r.err.msg = std::move(msg);
+ *error++ = ParseError<FwdIt>{ f, std::move(msg) };
+ return r;
};
ASTNode rhs;
@@ -185,12 +175,10 @@ parse_expr_binop_rhs(FwdIt f, FwdIt l, int precedence, ASTNode lhs)
}
{
- auto rpe = parse_expr_primary(f, l);
+ auto rpe = parse_expr_primary(f, l, error);
if (rpe.parsed == f) {
- err("failed at parsing primary expression:");
- r.err.msg += rpe.err.msg + "(at relative pos " +
- std::to_string(std::distance(f, rpe.err.pos)) + ")";
+ err("failed at parsing primary expression");
break;
}
@@ -204,14 +192,10 @@ parse_expr_binop_rhs(FwdIt f, FwdIt l, int precedence, ASTNode lhs)
}
if (tpred < token_precedence(*f)) { // there's an operator with higher prec
- auto rbo = parse_expr_binop_rhs(f, l, tpred + 1, std::move(rhs));
+ auto rbo = parse_expr_binop_rhs(f, l, tpred + 1, std::move(rhs), error);
- if (rbo.parsed == f) {
- err("error in parsing rhs: ");
- r.err.msg += rbo.err.msg + " (at relative pos " +
- std::to_string(std::distance(f, rbo.err.pos)) + ")";
- return r;
- }
+ if (rbo.parsed == f)
+ return err("error in parsing rhs");
f = rbo.parsed;
rhs = std::move(rbo.node);
@@ -225,18 +209,14 @@ parse_expr_binop_rhs(FwdIt f, FwdIt l, int precedence, ASTNode lhs)
return r;
}
-template<typename FwdIt>
-ParseResult<FwdIt>
-parse_expr(FwdIt f, FwdIt l);
-
-template<typename FwdIt>
+template<typename FwdIt, typename ErrOutIt>
ParseResult<FwdIt>
-parse_expr_primary(FwdIt f, FwdIt l)
+parse_expr_primary(FwdIt f, FwdIt l, ErrOutIt error)
{
ParseResult<FwdIt> r;
auto err = [&](auto&& msg) {
- r.err.pos = f;
- r.err.msg = std::move(msg);
+ *error = ParseError<FwdIt>{ f, std::move(msg) };
+ return r;
};
assert(f != l);
@@ -250,26 +230,22 @@ parse_expr_primary(FwdIt f, FwdIt l)
return r;
case TkType::Id:
- return parse_expr_idexpr(f, l);
+ return parse_expr_idexpr(f, l, error);
case TkType::Etc:
if (token_str(*f) == "(") {
++f;
- auto rpe = parse_expr(f, l);
+ auto rpe = parse_expr(f, l, error);
- if (rpe.parsed == f) {
- r.err = std::move(rpe.err);
- return r;
- }
+ if (rpe.parsed == f)
+ return err("failed parsing expression");
r.node = std::move(rpe.node);
f = rpe.parsed;
- if (f == l) {
- err("early termination: expects `)`");
- return r;
- }
+ if (f == l)
+ return err("early termination: expects `)`");
if (token_str(*f) == ")")
r.parsed = ++f;
@@ -282,22 +258,19 @@ parse_expr_primary(FwdIt f, FwdIt l)
/* fallthrough */
default:
- // FIXME performance of concat
- err(std::string{ "unexpected token (" } + kal::to_string(*f) +
- ") while expecting an expression");
- return r;
+ return err("unexpected token while expecting an expression");
}
return r;
}
-template<typename FwdIt>
+template<typename FwdIt, typename ErrOutIt>
ParseResult<FwdIt>
-parse_expr(FwdIt f, FwdIt l)
+parse_expr(FwdIt f, FwdIt l, ErrOutIt error)
{
assert(f != l);
- auto r = parse_expr_primary(f, l);
+ auto r = parse_expr_primary(f, l, error);
if (r.parsed == f)
return r; // CHKME std::move(r);
@@ -307,51 +280,52 @@ parse_expr(FwdIt f, FwdIt l)
if (f == l || token_precedence(*f) < 0) // not a valid operator
return r;
- return parse_expr_binop_rhs(f, l, 0, std::move(r.node));
+ return parse_expr_binop_rhs(f, l, 0, std::move(r.node), error);
}
} // namespace detail
-// TODO std::move err msg
-
-template<typename FwdIt, typename OutIt, typename ErrOp>
+template<typename FwdIt, typename OutIt, typename ErrOutIt>
FwdIt
-parse(FwdIt f, FwdIt l, OutIt nodes, ErrOp error)
+parse(FwdIt f, FwdIt l, OutIt nodes, ErrOutIt error)
{
- auto err = [&](FwdIt pos, const auto& msg) {
- error(pos, msg);
- return pos;
+ static_assert(std::is_assignable<decltype(*error), ParseError<FwdIt>>::value,
+ "");
+
+ auto err = [&](std::string&& msg) {
+ *error++ = ParseError<FwdIt>{ f, std::move(msg) };
+ return f;
};
while (f != l) {
switch (token_type(*f)) {
case TkType::Extern: {
if (++f == l)
- return err(f,
- "early termination: "
- "expects function prototype after `extern` keyword");
+ return err(
+ "early termination: "
+ "expects function prototype after `extern` keyword");
- auto r = detail::parse_prototype(f, l);
+ auto r = detail::parse_prototype(f, l, error);
if (r.parsed == f) // failure
- return err(r.err.pos, r.err.msg);
+ return err("parsing prototype failed");
f = r.parsed;
*nodes++ = std::move(r.node);
} break;
case TkType::Def: {
if (++f == l)
- return err(f,
- "early termination: "
- "expects function prototype after `def` keyword");
+ return err(
+ "early termination: "
+ "expects function prototype after `def` keyword");
kal::Prototype proto;
{
- auto r = detail::parse_prototype(f, l);
+ auto r = detail::parse_prototype(f, l, error);
if (r.parsed == f) // failure
- return err(r.err.pos, r.err.msg);
+ return err("parsing prototype failed");
{
using kal::cast; // FIXME
@@ -368,13 +342,13 @@ parse(FwdIt f, FwdIt l, OutIt nodes, ErrOp error)
}
if (f == l)
- return err(f, "early termination: expects function body");
+ return err("early termination: expects function body");
{
- auto r = detail::parse_expr(f, l);
+ auto r = detail::parse_expr(f, l, error);
if (r.parsed == f) // failure
- return err(r.err.pos, r.err.msg);
+ return err("parsing expression failed");
f = r.parsed;
*nodes++ = kal::Function{ std::move(proto), std::move(r.node) };
}
@@ -388,10 +362,10 @@ parse(FwdIt f, FwdIt l, OutIt nodes, ErrOp error)
/* fallthrough */
default: { // top-level expr
- auto r = detail::parse_expr(f, l);
+ auto r = detail::parse_expr(f, l, error);
if (r.parsed == f) // failure
- return err(r.err.pos, r.err.msg);
+ return err("parsing expression failed");
f = r.parsed;
*nodes++ = std::move(r.node);
} break;
diff --git a/tests/kaleidoscope_parser.test.cpp b/tests/kaleidoscope_parser.test.cpp
@@ -29,15 +29,24 @@ TEST_CASE("parse simple programs", "[simple]")
auto tkb = tk.cbegin();
auto tke = tk.cend();
+ std::vector<kal::ParseError<decltype(tkb)>> errs;
- kal::parse(
- tkb, tke, std::back_inserter(nd), [&](const auto& it, const auto& err) {
- auto pos = std::distance(tkb, it);
+ kal::parse(tkb, tke, std::back_inserter(nd), std::back_inserter(errs));
- FAIL("PARSER ERROR pos:" << pos << " err:\"" << err << '"');
- });
+ if (errs.empty())
+ return nd;
- return nd;
+ std::ostringstream oss;
+
+ for (auto& e : errs) {
+ oss << " Error@" << std::distance(tkb, e.pos) << ' ' << e.msg;
+
+ if (e.pos != tke)
+ oss << '\n' << kal::to_string(*e.pos) << "\n";
+ }
+
+ FAIL("PARSER ERROR\n" << oss.str());
+ return nd; // dummy
};
SECTION("extern")
