1 //===-- GoParser.cpp ---------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
14 #include "Plugins/ExpressionParser/Go/GoAST.h"
15 #include "lldb/Core/Error.h"
16 #include "llvm/ADT/SmallString.h"
18 using namespace lldb_private;
22 llvm::StringRef DescribeToken(GoLexer::TokenType t) {
24 case GoLexer::TOK_EOF:
26 case GoLexer::TOK_IDENTIFIER:
28 case GoLexer::LIT_FLOAT:
30 case GoLexer::LIT_IMAGINARY:
32 case GoLexer::LIT_INTEGER:
34 case GoLexer::LIT_RUNE:
36 case GoLexer::LIT_STRING:
39 return GoLexer::LookupToken(t);
44 class GoParser::Rule {
46 Rule(llvm::StringRef name, GoParser *p)
47 : m_name(name), m_parser(p), m_pos(p->m_pos) {}
49 std::nullptr_t error() {
50 if (!m_parser->m_failed) {
51 // Set m_error in case this is the top level.
52 if (m_parser->m_last_tok == GoLexer::TOK_INVALID)
53 m_parser->m_error = m_parser->m_last;
55 m_parser->m_error = DescribeToken(m_parser->m_last_tok);
56 // And set m_last in case it isn't.
57 m_parser->m_last = m_name;
58 m_parser->m_last_tok = GoLexer::TOK_INVALID;
59 m_parser->m_pos = m_pos;
65 llvm::StringRef m_name;
70 GoParser::GoParser(const char *src) : m_lexer(src), m_pos(0), m_failed(false) {}
72 GoASTStmt *GoParser::Statement() {
73 Rule r("Statement", this);
74 GoLexer::TokenType t = peek();
75 GoASTStmt *ret = nullptr;
77 case GoLexer::TOK_EOF:
78 case GoLexer::OP_SEMICOLON:
79 case GoLexer::OP_RPAREN:
80 case GoLexer::OP_RBRACE:
81 case GoLexer::TOK_INVALID:
83 case GoLexer::OP_LBRACE:
87 case GoLexer::KEYWORD_GO:
89 case GoLexer::KEYWORD_RETURN:
91 case GoLexer::KEYWORD_BREAK:
92 case GoLexer::KEYWORD_CONTINUE:
93 case GoLexer::KEYWORD_GOTO:
94 case GoLexer::KEYWORD_FALLTHROUGH:
96 case GoLexer::KEYWORD_IF:
98 case GoLexer::KEYWORD_SWITCH:
100 case GoLexer::KEYWORD_SELECT:
102 case GoLexer::KEYWORD_FOR:
104 case GoLexer::KEYWORD_DEFER:
106 case GoLexer::KEYWORD_CONST:
107 case GoLexer::KEYWORD_TYPE:
108 case GoLexer::KEYWORD_VAR:
110 case GoLexer::TOK_IDENTIFIER:
111 if ((ret = LabeledStmt()) ||
112 (ret = ShortVarDecl()))
120 GoASTExpr *expr = Expression();
123 if (/*(ret = SendStmt(expr)) ||*/
124 (ret = IncDecStmt(expr)) || (ret = Assignment(expr)) ||
125 (ret = ExpressionStmt(expr))) {
132 GoASTStmt *GoParser::ExpressionStmt(GoASTExpr *e) {
134 return new GoASTExprStmt(e);
138 GoASTStmt *GoParser::IncDecStmt(GoASTExpr *e) {
139 Rule r("IncDecStmt", this);
140 if (match(GoLexer::OP_PLUS_PLUS))
141 return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_PLUS_PLUS)
143 if (match(GoLexer::OP_MINUS_MINUS))
144 return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_MINUS_MINUS)
149 GoASTStmt *GoParser::Assignment(lldb_private::GoASTExpr *e) {
150 Rule r("Assignment", this);
151 std::vector<std::unique_ptr<GoASTExpr>> lhs;
152 for (GoASTExpr *l = MoreExpressionList(); l; l = MoreExpressionList())
153 lhs.push_back(std::unique_ptr<GoASTExpr>(l));
156 case GoLexer::OP_PLUS_EQ:
157 case GoLexer::OP_MINUS_EQ:
158 case GoLexer::OP_PIPE_EQ:
159 case GoLexer::OP_CARET_EQ:
160 case GoLexer::OP_STAR_EQ:
161 case GoLexer::OP_SLASH_EQ:
162 case GoLexer::OP_PERCENT_EQ:
163 case GoLexer::OP_LSHIFT_EQ:
164 case GoLexer::OP_RSHIFT_EQ:
165 case GoLexer::OP_AMP_EQ:
166 case GoLexer::OP_AMP_CARET_EQ:
171 // We don't want to own e until we know this is an assignment.
172 std::unique_ptr<GoASTAssignStmt> stmt(new GoASTAssignStmt(false));
175 stmt->AddLhs(l.release());
176 for (GoASTExpr *r = Expression(); r; r = MoreExpressionList())
178 if (!Semicolon() || stmt->NumRhs() == 0)
179 return new GoASTBadStmt;
180 return stmt.release();
183 GoASTStmt *GoParser::EmptyStmt() {
184 if (match(GoLexer::TOK_EOF))
187 return new GoASTEmptyStmt;
191 GoASTStmt *GoParser::GoStmt() {
192 if (match(GoLexer::KEYWORD_GO)) {
193 if (GoASTCallExpr *e =
194 llvm::dyn_cast_or_null<GoASTCallExpr>(Expression())) {
195 return FinishStmt(new GoASTGoStmt(e));
197 m_last = "call expression";
199 return new GoASTBadStmt();
204 GoASTStmt *GoParser::ReturnStmt() {
205 if (match(GoLexer::KEYWORD_RETURN)) {
206 std::unique_ptr<GoASTReturnStmt> r(new GoASTReturnStmt());
207 for (GoASTExpr *e = Expression(); e; e = MoreExpressionList())
209 return FinishStmt(r.release());
214 GoASTStmt *GoParser::BranchStmt() {
216 if ((tok = match(GoLexer::KEYWORD_BREAK)) ||
217 (tok = match(GoLexer::KEYWORD_CONTINUE)) ||
218 (tok = match(GoLexer::KEYWORD_GOTO))) {
219 auto *e = Identifier();
220 if (tok->m_type == GoLexer::KEYWORD_GOTO && !e)
221 return syntaxerror();
222 return FinishStmt(new GoASTBranchStmt(e, tok->m_type));
224 if ((tok = match(GoLexer::KEYWORD_FALLTHROUGH)))
225 return FinishStmt(new GoASTBranchStmt(nullptr, tok->m_type));
230 GoASTIdent *GoParser::Identifier() {
231 if (auto *tok = match(GoLexer::TOK_IDENTIFIER))
232 return new GoASTIdent(*tok);
236 GoASTExpr *GoParser::MoreExpressionList() {
237 if (match(GoLexer::OP_COMMA)) {
238 auto *e = Expression();
240 return syntaxerror();
246 GoASTIdent *GoParser::MoreIdentifierList() {
247 if (match(GoLexer::OP_COMMA)) {
248 auto *i = Identifier();
250 return syntaxerror();
256 GoASTExpr *GoParser::Expression() {
257 Rule r("Expression", this);
258 if (GoASTExpr *ret = OrExpr())
263 GoASTExpr *GoParser::UnaryExpr() {
265 case GoLexer::OP_PLUS:
266 case GoLexer::OP_MINUS:
267 case GoLexer::OP_BANG:
268 case GoLexer::OP_CARET:
269 case GoLexer::OP_STAR:
270 case GoLexer::OP_AMP:
271 case GoLexer::OP_LT_MINUS: {
272 const GoLexer::Token t = next();
273 if (GoASTExpr *e = UnaryExpr()) {
274 if (t.m_type == GoLexer::OP_STAR)
275 return new GoASTStarExpr(e);
277 return new GoASTUnaryExpr(t.m_type, e);
279 return syntaxerror();
282 return PrimaryExpr();
286 GoASTExpr *GoParser::OrExpr() {
287 std::unique_ptr<GoASTExpr> l(AndExpr());
289 while (match(GoLexer::OP_PIPE_PIPE)) {
290 GoASTExpr *r = AndExpr();
292 l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_PIPE_PIPE));
294 return syntaxerror();
301 GoASTExpr *GoParser::AndExpr() {
302 std::unique_ptr<GoASTExpr> l(RelExpr());
304 while (match(GoLexer::OP_AMP_AMP)) {
305 GoASTExpr *r = RelExpr();
307 l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_AMP_AMP));
309 return syntaxerror();
316 GoASTExpr *GoParser::RelExpr() {
317 std::unique_ptr<GoASTExpr> l(AddExpr());
319 for (GoLexer::Token *t;
320 (t = match(GoLexer::OP_EQ_EQ)) || (t = match(GoLexer::OP_BANG_EQ)) ||
321 (t = match(GoLexer::OP_LT)) || (t = match(GoLexer::OP_LT_EQ)) ||
322 (t = match(GoLexer::OP_GT)) || (t = match(GoLexer::OP_GT_EQ));) {
323 GoLexer::TokenType op = t->m_type;
324 GoASTExpr *r = AddExpr();
326 l.reset(new GoASTBinaryExpr(l.release(), r, op));
328 return syntaxerror();
335 GoASTExpr *GoParser::AddExpr() {
336 std::unique_ptr<GoASTExpr> l(MulExpr());
338 for (GoLexer::Token *t;
339 (t = match(GoLexer::OP_PLUS)) || (t = match(GoLexer::OP_MINUS)) ||
340 (t = match(GoLexer::OP_PIPE)) || (t = match(GoLexer::OP_CARET));) {
341 GoLexer::TokenType op = t->m_type;
342 GoASTExpr *r = MulExpr();
344 l.reset(new GoASTBinaryExpr(l.release(), r, op));
346 return syntaxerror();
353 GoASTExpr *GoParser::MulExpr() {
354 std::unique_ptr<GoASTExpr> l(UnaryExpr());
356 for (GoLexer::Token *t;
357 (t = match(GoLexer::OP_STAR)) || (t = match(GoLexer::OP_SLASH)) ||
358 (t = match(GoLexer::OP_PERCENT)) || (t = match(GoLexer::OP_LSHIFT)) ||
359 (t = match(GoLexer::OP_RSHIFT)) || (t = match(GoLexer::OP_AMP)) ||
360 (t = match(GoLexer::OP_AMP_CARET));) {
361 GoLexer::TokenType op = t->m_type;
362 GoASTExpr *r = UnaryExpr();
364 l.reset(new GoASTBinaryExpr(l.release(), r, op));
366 return syntaxerror();
373 GoASTExpr *GoParser::PrimaryExpr() {
376 (l = Conversion()) || (l = Operand());
379 while ((r = Selector(l)) || (r = IndexOrSlice(l)) || (r = TypeAssertion(l)) ||
380 (r = Arguments(l))) {
386 GoASTExpr *GoParser::Operand() {
388 if ((lit = match(GoLexer::LIT_INTEGER)) ||
389 (lit = match(GoLexer::LIT_FLOAT)) ||
390 (lit = match(GoLexer::LIT_IMAGINARY)) ||
391 (lit = match(GoLexer::LIT_RUNE)) || (lit = match(GoLexer::LIT_STRING)))
392 return new GoASTBasicLit(*lit);
393 if (match(GoLexer::OP_LPAREN)) {
395 if (!((e = Expression()) && match(GoLexer::OP_RPAREN)))
396 return syntaxerror();
399 // MethodExpr should be handled by Selector
400 if (GoASTExpr *e = CompositeLit())
402 if (GoASTExpr *n = Name())
404 return FunctionLit();
407 GoASTExpr *GoParser::FunctionLit() {
408 if (!match(GoLexer::KEYWORD_FUNC))
410 auto *sig = Signature();
412 return syntaxerror();
413 auto *body = Block();
416 return syntaxerror();
418 return new GoASTFuncLit(sig, body);
421 GoASTBlockStmt *GoParser::Block() {
422 if (!match(GoLexer::OP_LBRACE))
424 std::unique_ptr<GoASTBlockStmt> block(new GoASTBlockStmt);
425 for (auto *s = Statement(); s; s = Statement())
427 if (!match(GoLexer::OP_RBRACE))
428 return syntaxerror();
429 return block.release();
432 GoASTExpr *GoParser::CompositeLit() {
433 Rule r("CompositeLit", this);
435 (type = StructType()) || (type = ArrayOrSliceType(true)) ||
436 (type = MapType()) || (type = Name());
439 GoASTCompositeLit *lit = LiteralValue();
446 GoASTCompositeLit *GoParser::LiteralValue() {
447 if (!match(GoLexer::OP_LBRACE))
449 std::unique_ptr<GoASTCompositeLit> lit(new GoASTCompositeLit);
450 for (GoASTExpr *e = Element(); e; e = Element()) {
452 if (!match(GoLexer::OP_COMMA))
455 if (!mustMatch(GoLexer::OP_RBRACE))
457 return lit.release();
460 GoASTExpr *GoParser::Element() {
462 if (!((key = Expression()) || (key = LiteralValue())))
464 if (!match(GoLexer::OP_COLON))
467 if ((value = Expression()) || (value = LiteralValue()))
468 return new GoASTKeyValueExpr(key, value);
470 return syntaxerror();
473 GoASTExpr *GoParser::Selector(GoASTExpr *e) {
474 Rule r("Selector", this);
475 if (match(GoLexer::OP_DOT)) {
476 if (auto *name = Identifier())
477 return new GoASTSelectorExpr(e, name);
482 GoASTExpr *GoParser::IndexOrSlice(GoASTExpr *e) {
483 Rule r("IndexOrSlice", this);
484 if (match(GoLexer::OP_LBRACK)) {
485 std::unique_ptr<GoASTExpr> i1(Expression()), i2, i3;
487 if (match(GoLexer::OP_COLON)) {
489 i2.reset(Expression());
490 if (i2 && match(GoLexer::OP_COLON)) {
491 i3.reset(Expression());
493 return syntaxerror();
497 return syntaxerror();
498 if (!mustMatch(GoLexer::OP_RBRACK))
501 bool slice3 = i3.get();
502 return new GoASTSliceExpr(e, i1.release(), i2.release(), i3.release(),
505 return new GoASTIndexExpr(e, i1.release());
510 GoASTExpr *GoParser::TypeAssertion(GoASTExpr *e) {
511 Rule r("TypeAssertion", this);
512 if (match(GoLexer::OP_DOT) && match(GoLexer::OP_LPAREN)) {
513 if (auto *t = Type()) {
514 if (!mustMatch(GoLexer::OP_RPAREN))
516 return new GoASTTypeAssertExpr(e, t);
518 return syntaxerror();
523 GoASTExpr *GoParser::Arguments(GoASTExpr *e) {
524 if (match(GoLexer::OP_LPAREN)) {
525 std::unique_ptr<GoASTCallExpr> call(new GoASTCallExpr(false));
527 // ( ExpressionList | Type [ "," ExpressionList ] )
528 for ((arg = Expression()) || (arg = Type()); arg;
529 arg = MoreExpressionList()) {
532 if (match(GoLexer::OP_DOTS))
533 call->SetEllipsis(true);
535 // Eat trailing comma
536 match(GoLexer::OP_COMMA);
538 if (!mustMatch(GoLexer::OP_RPAREN))
541 return call.release();
546 GoASTExpr *GoParser::Conversion() {
547 Rule r("Conversion", this);
548 if (GoASTExpr *t = Type2()) {
549 if (match(GoLexer::OP_LPAREN)) {
550 GoASTExpr *v = Expression();
552 return syntaxerror();
553 match(GoLexer::OP_COMMA);
554 if (!mustMatch(GoLexer::OP_RPAREN))
556 GoASTCallExpr *call = new GoASTCallExpr(false);
565 GoASTExpr *GoParser::Type2() {
567 case GoLexer::OP_LBRACK:
568 return ArrayOrSliceType(false);
569 case GoLexer::KEYWORD_STRUCT:
571 case GoLexer::KEYWORD_FUNC:
572 return FunctionType();
573 case GoLexer::KEYWORD_INTERFACE:
574 return InterfaceType();
575 case GoLexer::KEYWORD_MAP:
577 case GoLexer::KEYWORD_CHAN:
584 GoASTExpr *GoParser::ArrayOrSliceType(bool allowEllipsis) {
585 Rule r("ArrayType", this);
586 if (match(GoLexer::OP_LBRACK)) {
587 std::unique_ptr<GoASTExpr> len;
588 if (allowEllipsis && match(GoLexer::OP_DOTS)) {
589 len.reset(new GoASTEllipsis(nullptr));
591 len.reset(Expression());
594 if (!match(GoLexer::OP_RBRACK))
596 GoASTExpr *elem = Type();
598 return syntaxerror();
599 return new GoASTArrayType(len.release(), elem);
604 GoASTExpr *GoParser::StructType() {
605 if (!(match(GoLexer::KEYWORD_STRUCT) && mustMatch(GoLexer::OP_LBRACE)))
607 std::unique_ptr<GoASTFieldList> fields(new GoASTFieldList);
608 while (auto *field = FieldDecl())
609 fields->AddList(field);
610 if (!mustMatch(GoLexer::OP_RBRACE))
612 return new GoASTStructType(fields.release());
615 GoASTField *GoParser::FieldDecl() {
616 std::unique_ptr<GoASTField> f(new GoASTField);
617 GoASTExpr *t = FieldNamesAndType(f.get());
619 t = AnonymousFieldType();
623 if (auto *tok = match(GoLexer::LIT_STRING))
624 f->SetTag(new GoASTBasicLit(*tok));
626 return syntaxerror();
630 GoASTExpr *GoParser::FieldNamesAndType(GoASTField *field) {
631 Rule r("FieldNames", this);
632 for (auto *id = Identifier(); id; id = MoreIdentifierList())
636 GoASTExpr *t = Type();
642 GoASTExpr *GoParser::AnonymousFieldType() {
643 bool pointer = match(GoLexer::OP_STAR);
644 GoASTExpr *t = Type();
648 return new GoASTStarExpr(t);
652 GoASTExpr *GoParser::FunctionType() {
653 if (!match(GoLexer::KEYWORD_FUNC))
658 GoASTFuncType *GoParser::Signature() {
659 auto *params = Params();
661 return syntaxerror();
662 auto *result = Params();
664 if (auto *t = Type()) {
665 result = new GoASTFieldList;
666 auto *f = new GoASTField;
671 return new GoASTFuncType(params, result);
674 GoASTFieldList *GoParser::Params() {
675 if (!match(GoLexer::OP_LPAREN))
677 std::unique_ptr<GoASTFieldList> l(new GoASTFieldList);
678 while (GoASTField *p = ParamDecl()) {
680 if (!match(GoLexer::OP_COMMA))
683 if (!mustMatch(GoLexer::OP_RPAREN))
688 GoASTField *GoParser::ParamDecl() {
689 std::unique_ptr<GoASTField> field(new GoASTField);
690 GoASTIdent *id = Identifier();
692 // Try `IdentifierList [ "..." ] Type`.
693 // If that fails, backtrack and try `[ "..." ] Type`.
694 Rule r("NamedParam", this);
695 for (; id; id = MoreIdentifierList())
697 GoASTExpr *t = ParamType();
700 return field.release();
702 field.reset(new GoASTField);
705 GoASTExpr *t = ParamType();
708 return field.release();
713 GoASTExpr *GoParser::ParamType() {
714 bool dots = match(GoLexer::OP_DOTS);
715 GoASTExpr *t = Type();
719 return syntaxerror();
720 return new GoASTEllipsis(t);
723 GoASTExpr *GoParser::InterfaceType() {
724 if (!match(GoLexer::KEYWORD_INTERFACE) || !mustMatch(GoLexer::OP_LBRACE))
726 std::unique_ptr<GoASTFieldList> methods(new GoASTFieldList);
728 Rule r("MethodSpec", this);
729 // ( identifier Signature | TypeName ) ;
730 std::unique_ptr<GoASTIdent> id(Identifier());
733 GoASTExpr *type = Signature();
740 return syntaxerror();
741 auto *f = new GoASTField;
743 f->AddNames(id.release());
747 if (!mustMatch(GoLexer::OP_RBRACE))
749 return new GoASTInterfaceType(methods.release());
752 GoASTExpr *GoParser::MapType() {
753 if (!(match(GoLexer::KEYWORD_MAP) && mustMatch(GoLexer::OP_LBRACK)))
755 std::unique_ptr<GoASTExpr> key(Type());
757 return syntaxerror();
758 if (!mustMatch(GoLexer::OP_RBRACK))
762 return syntaxerror();
763 return new GoASTMapType(key.release(), elem);
766 GoASTExpr *GoParser::ChanType() {
767 Rule r("chan", this);
768 if (match(GoLexer::OP_LT_MINUS)) {
769 if (match(GoLexer::KEYWORD_CHAN)) {
772 return syntaxerror();
773 return new GoASTChanType(GoASTNode::eChanRecv, elem);
780 GoASTExpr *GoParser::ChanType2() {
781 if (!match(GoLexer::KEYWORD_CHAN))
783 auto dir = GoASTNode::eChanBidir;
784 if (match(GoLexer::OP_LT_MINUS))
785 dir = GoASTNode::eChanSend;
788 return syntaxerror();
789 return new GoASTChanType(dir, elem);
792 GoASTExpr *GoParser::Type() {
793 if (GoASTExpr *t = Type2())
795 if (GoASTExpr *t = Name())
797 if (GoASTExpr *t = ChanType())
799 if (match(GoLexer::OP_STAR)) {
800 GoASTExpr *t = Type();
802 return syntaxerror();
803 return new GoASTStarExpr(t);
805 if (match(GoLexer::OP_LPAREN)) {
806 std::unique_ptr<GoASTExpr> t(Type());
807 if (!t || !match(GoLexer::OP_RPAREN))
808 return syntaxerror();
814 bool GoParser::Semicolon() {
815 if (match(GoLexer::OP_SEMICOLON))
818 case GoLexer::OP_RPAREN:
819 case GoLexer::OP_RBRACE:
820 case GoLexer::TOK_EOF:
827 GoASTExpr *GoParser::Name() {
828 if (auto *id = Identifier()) {
829 if (GoASTExpr *qual = QualifiedIdent(id))
836 GoASTExpr *GoParser::QualifiedIdent(lldb_private::GoASTIdent *p) {
837 Rule r("QualifiedIdent", this);
838 llvm::SmallString<32> path(p->GetName().m_value);
839 GoLexer::Token *next;
840 bool have_slashes = false;
841 // LLDB extension: support full/package/path.name
842 while (match(GoLexer::OP_SLASH) && (next = match(GoLexer::TOK_IDENTIFIER))) {
845 path.append(next->m_value);
847 if (match(GoLexer::OP_DOT)) {
848 auto *name = Identifier();
851 p->SetName(GoLexer::Token(GoLexer::TOK_IDENTIFIER, CopyString(path)));
853 return new GoASTSelectorExpr(p, name);
859 llvm::StringRef GoParser::CopyString(llvm::StringRef s) {
860 return m_strings.insert(std::make_pair(s, 'x')).first->getKey();
863 void GoParser::GetError(Error &error) {
864 llvm::StringRef want;
867 m_last_tok == GoLexer::TOK_INVALID ? DescribeToken(m_last_tok) : m_last;
870 size_t len = m_lexer.BytesRemaining();
877 got = m_lexer.GetString(len);
878 error.SetErrorStringWithFormat("Syntax error: expected %s before '%s'.",
879 want.str().c_str(), got.str().c_str());