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/Utility/Status.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)
71 : m_lexer(src), m_pos(0), m_last_tok(GoLexer::TOK_INVALID),
74 GoASTStmt *GoParser::Statement() {
75 Rule r("Statement", this);
76 GoLexer::TokenType t = peek();
77 GoASTStmt *ret = nullptr;
79 case GoLexer::TOK_EOF:
80 case GoLexer::OP_SEMICOLON:
81 case GoLexer::OP_RPAREN:
82 case GoLexer::OP_RBRACE:
83 case GoLexer::TOK_INVALID:
85 case GoLexer::OP_LBRACE:
89 case GoLexer::KEYWORD_GO:
91 case GoLexer::KEYWORD_RETURN:
93 case GoLexer::KEYWORD_BREAK:
94 case GoLexer::KEYWORD_CONTINUE:
95 case GoLexer::KEYWORD_GOTO:
96 case GoLexer::KEYWORD_FALLTHROUGH:
98 case GoLexer::KEYWORD_IF:
100 case GoLexer::KEYWORD_SWITCH:
102 case GoLexer::KEYWORD_SELECT:
104 case GoLexer::KEYWORD_FOR:
106 case GoLexer::KEYWORD_DEFER:
108 case GoLexer::KEYWORD_CONST:
109 case GoLexer::KEYWORD_TYPE:
110 case GoLexer::KEYWORD_VAR:
112 case GoLexer::TOK_IDENTIFIER:
113 if ((ret = LabeledStmt()) ||
114 (ret = ShortVarDecl()))
122 GoASTExpr *expr = Expression();
125 if (/*(ret = SendStmt(expr)) ||*/
126 (ret = IncDecStmt(expr)) || (ret = Assignment(expr)) ||
127 (ret = ExpressionStmt(expr))) {
134 GoASTStmt *GoParser::ExpressionStmt(GoASTExpr *e) {
136 return new GoASTExprStmt(e);
140 GoASTStmt *GoParser::IncDecStmt(GoASTExpr *e) {
141 Rule r("IncDecStmt", this);
142 if (match(GoLexer::OP_PLUS_PLUS))
143 return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_PLUS_PLUS)
145 if (match(GoLexer::OP_MINUS_MINUS))
146 return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_MINUS_MINUS)
151 GoASTStmt *GoParser::Assignment(lldb_private::GoASTExpr *e) {
152 Rule r("Assignment", this);
153 std::vector<std::unique_ptr<GoASTExpr>> lhs;
154 for (GoASTExpr *l = MoreExpressionList(); l; l = MoreExpressionList())
155 lhs.push_back(std::unique_ptr<GoASTExpr>(l));
158 case GoLexer::OP_PLUS_EQ:
159 case GoLexer::OP_MINUS_EQ:
160 case GoLexer::OP_PIPE_EQ:
161 case GoLexer::OP_CARET_EQ:
162 case GoLexer::OP_STAR_EQ:
163 case GoLexer::OP_SLASH_EQ:
164 case GoLexer::OP_PERCENT_EQ:
165 case GoLexer::OP_LSHIFT_EQ:
166 case GoLexer::OP_RSHIFT_EQ:
167 case GoLexer::OP_AMP_EQ:
168 case GoLexer::OP_AMP_CARET_EQ:
173 // We don't want to own e until we know this is an assignment.
174 std::unique_ptr<GoASTAssignStmt> stmt(new GoASTAssignStmt(false));
177 stmt->AddLhs(l.release());
178 for (GoASTExpr *r = Expression(); r; r = MoreExpressionList())
180 if (!Semicolon() || stmt->NumRhs() == 0)
181 return new GoASTBadStmt;
182 return stmt.release();
185 GoASTStmt *GoParser::EmptyStmt() {
186 if (match(GoLexer::TOK_EOF))
189 return new GoASTEmptyStmt;
193 GoASTStmt *GoParser::GoStmt() {
194 if (match(GoLexer::KEYWORD_GO)) {
195 if (GoASTCallExpr *e =
196 llvm::dyn_cast_or_null<GoASTCallExpr>(Expression())) {
197 return FinishStmt(new GoASTGoStmt(e));
199 m_last = "call expression";
201 return new GoASTBadStmt();
206 GoASTStmt *GoParser::ReturnStmt() {
207 if (match(GoLexer::KEYWORD_RETURN)) {
208 std::unique_ptr<GoASTReturnStmt> r(new GoASTReturnStmt());
209 for (GoASTExpr *e = Expression(); e; e = MoreExpressionList())
211 return FinishStmt(r.release());
216 GoASTStmt *GoParser::BranchStmt() {
218 if ((tok = match(GoLexer::KEYWORD_BREAK)) ||
219 (tok = match(GoLexer::KEYWORD_CONTINUE)) ||
220 (tok = match(GoLexer::KEYWORD_GOTO))) {
221 auto *e = Identifier();
222 if (tok->m_type == GoLexer::KEYWORD_GOTO && !e)
223 return syntaxerror();
224 return FinishStmt(new GoASTBranchStmt(e, tok->m_type));
226 if ((tok = match(GoLexer::KEYWORD_FALLTHROUGH)))
227 return FinishStmt(new GoASTBranchStmt(nullptr, tok->m_type));
232 GoASTIdent *GoParser::Identifier() {
233 if (auto *tok = match(GoLexer::TOK_IDENTIFIER))
234 return new GoASTIdent(*tok);
238 GoASTExpr *GoParser::MoreExpressionList() {
239 if (match(GoLexer::OP_COMMA)) {
240 auto *e = Expression();
242 return syntaxerror();
248 GoASTIdent *GoParser::MoreIdentifierList() {
249 if (match(GoLexer::OP_COMMA)) {
250 auto *i = Identifier();
252 return syntaxerror();
258 GoASTExpr *GoParser::Expression() {
259 Rule r("Expression", this);
260 if (GoASTExpr *ret = OrExpr())
265 GoASTExpr *GoParser::UnaryExpr() {
267 case GoLexer::OP_PLUS:
268 case GoLexer::OP_MINUS:
269 case GoLexer::OP_BANG:
270 case GoLexer::OP_CARET:
271 case GoLexer::OP_STAR:
272 case GoLexer::OP_AMP:
273 case GoLexer::OP_LT_MINUS: {
274 const GoLexer::Token t = next();
275 if (GoASTExpr *e = UnaryExpr()) {
276 if (t.m_type == GoLexer::OP_STAR)
277 return new GoASTStarExpr(e);
279 return new GoASTUnaryExpr(t.m_type, e);
281 return syntaxerror();
284 return PrimaryExpr();
288 GoASTExpr *GoParser::OrExpr() {
289 std::unique_ptr<GoASTExpr> l(AndExpr());
291 while (match(GoLexer::OP_PIPE_PIPE)) {
292 GoASTExpr *r = AndExpr();
294 l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_PIPE_PIPE));
296 return syntaxerror();
303 GoASTExpr *GoParser::AndExpr() {
304 std::unique_ptr<GoASTExpr> l(RelExpr());
306 while (match(GoLexer::OP_AMP_AMP)) {
307 GoASTExpr *r = RelExpr();
309 l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_AMP_AMP));
311 return syntaxerror();
318 GoASTExpr *GoParser::RelExpr() {
319 std::unique_ptr<GoASTExpr> l(AddExpr());
321 for (GoLexer::Token *t;
322 (t = match(GoLexer::OP_EQ_EQ)) || (t = match(GoLexer::OP_BANG_EQ)) ||
323 (t = match(GoLexer::OP_LT)) || (t = match(GoLexer::OP_LT_EQ)) ||
324 (t = match(GoLexer::OP_GT)) || (t = match(GoLexer::OP_GT_EQ));) {
325 GoLexer::TokenType op = t->m_type;
326 GoASTExpr *r = AddExpr();
328 l.reset(new GoASTBinaryExpr(l.release(), r, op));
330 return syntaxerror();
337 GoASTExpr *GoParser::AddExpr() {
338 std::unique_ptr<GoASTExpr> l(MulExpr());
340 for (GoLexer::Token *t;
341 (t = match(GoLexer::OP_PLUS)) || (t = match(GoLexer::OP_MINUS)) ||
342 (t = match(GoLexer::OP_PIPE)) || (t = match(GoLexer::OP_CARET));) {
343 GoLexer::TokenType op = t->m_type;
344 GoASTExpr *r = MulExpr();
346 l.reset(new GoASTBinaryExpr(l.release(), r, op));
348 return syntaxerror();
355 GoASTExpr *GoParser::MulExpr() {
356 std::unique_ptr<GoASTExpr> l(UnaryExpr());
358 for (GoLexer::Token *t;
359 (t = match(GoLexer::OP_STAR)) || (t = match(GoLexer::OP_SLASH)) ||
360 (t = match(GoLexer::OP_PERCENT)) || (t = match(GoLexer::OP_LSHIFT)) ||
361 (t = match(GoLexer::OP_RSHIFT)) || (t = match(GoLexer::OP_AMP)) ||
362 (t = match(GoLexer::OP_AMP_CARET));) {
363 GoLexer::TokenType op = t->m_type;
364 GoASTExpr *r = UnaryExpr();
366 l.reset(new GoASTBinaryExpr(l.release(), r, op));
368 return syntaxerror();
375 GoASTExpr *GoParser::PrimaryExpr() {
378 (l = Conversion()) || (l = Operand());
381 while ((r = Selector(l)) || (r = IndexOrSlice(l)) || (r = TypeAssertion(l)) ||
382 (r = Arguments(l))) {
388 GoASTExpr *GoParser::Operand() {
390 if ((lit = match(GoLexer::LIT_INTEGER)) ||
391 (lit = match(GoLexer::LIT_FLOAT)) ||
392 (lit = match(GoLexer::LIT_IMAGINARY)) ||
393 (lit = match(GoLexer::LIT_RUNE)) || (lit = match(GoLexer::LIT_STRING)))
394 return new GoASTBasicLit(*lit);
395 if (match(GoLexer::OP_LPAREN)) {
397 if (!((e = Expression()) && match(GoLexer::OP_RPAREN)))
398 return syntaxerror();
401 // MethodExpr should be handled by Selector
402 if (GoASTExpr *e = CompositeLit())
404 if (GoASTExpr *n = Name())
406 return FunctionLit();
409 GoASTExpr *GoParser::FunctionLit() {
410 if (!match(GoLexer::KEYWORD_FUNC))
412 auto *sig = Signature();
414 return syntaxerror();
415 auto *body = Block();
418 return syntaxerror();
420 return new GoASTFuncLit(sig, body);
423 GoASTBlockStmt *GoParser::Block() {
424 if (!match(GoLexer::OP_LBRACE))
426 std::unique_ptr<GoASTBlockStmt> block(new GoASTBlockStmt);
427 for (auto *s = Statement(); s; s = Statement())
429 if (!match(GoLexer::OP_RBRACE))
430 return syntaxerror();
431 return block.release();
434 GoASTExpr *GoParser::CompositeLit() {
435 Rule r("CompositeLit", this);
437 (type = StructType()) || (type = ArrayOrSliceType(true)) ||
438 (type = MapType()) || (type = Name());
441 GoASTCompositeLit *lit = LiteralValue();
450 GoASTCompositeLit *GoParser::LiteralValue() {
451 if (!match(GoLexer::OP_LBRACE))
453 std::unique_ptr<GoASTCompositeLit> lit(new GoASTCompositeLit);
454 for (GoASTExpr *e = Element(); e; e = Element()) {
456 if (!match(GoLexer::OP_COMMA))
459 if (!mustMatch(GoLexer::OP_RBRACE))
461 return lit.release();
464 GoASTExpr *GoParser::Element() {
466 if (!((key = Expression()) || (key = LiteralValue())))
468 if (!match(GoLexer::OP_COLON))
471 if ((value = Expression()) || (value = LiteralValue()))
472 return new GoASTKeyValueExpr(key, value);
474 return syntaxerror();
477 GoASTExpr *GoParser::Selector(GoASTExpr *e) {
478 Rule r("Selector", this);
479 if (match(GoLexer::OP_DOT)) {
480 if (auto *name = Identifier())
481 return new GoASTSelectorExpr(e, name);
486 GoASTExpr *GoParser::IndexOrSlice(GoASTExpr *e) {
487 Rule r("IndexOrSlice", this);
488 if (match(GoLexer::OP_LBRACK)) {
489 std::unique_ptr<GoASTExpr> i1(Expression()), i2, i3;
491 if (match(GoLexer::OP_COLON)) {
493 i2.reset(Expression());
494 if (i2 && match(GoLexer::OP_COLON)) {
495 i3.reset(Expression());
497 return syntaxerror();
501 return syntaxerror();
502 if (!mustMatch(GoLexer::OP_RBRACK))
505 bool slice3 = i3.get();
506 return new GoASTSliceExpr(e, i1.release(), i2.release(), i3.release(),
509 return new GoASTIndexExpr(e, i1.release());
514 GoASTExpr *GoParser::TypeAssertion(GoASTExpr *e) {
515 Rule r("TypeAssertion", this);
516 if (match(GoLexer::OP_DOT) && match(GoLexer::OP_LPAREN)) {
517 if (auto *t = Type()) {
518 if (!mustMatch(GoLexer::OP_RPAREN))
520 return new GoASTTypeAssertExpr(e, t);
522 return syntaxerror();
527 GoASTExpr *GoParser::Arguments(GoASTExpr *e) {
528 if (match(GoLexer::OP_LPAREN)) {
529 std::unique_ptr<GoASTCallExpr> call(new GoASTCallExpr(false));
531 // ( ExpressionList | Type [ "," ExpressionList ] )
532 for ((arg = Expression()) || (arg = Type()); arg;
533 arg = MoreExpressionList()) {
536 if (match(GoLexer::OP_DOTS))
537 call->SetEllipsis(true);
539 // Eat trailing comma
540 match(GoLexer::OP_COMMA);
542 if (!mustMatch(GoLexer::OP_RPAREN))
545 return call.release();
550 GoASTExpr *GoParser::Conversion() {
551 Rule r("Conversion", this);
552 if (GoASTExpr *t = Type2()) {
553 std::unique_ptr<GoASTExpr> owner(t);
554 if (match(GoLexer::OP_LPAREN)) {
555 GoASTExpr *v = Expression();
557 return syntaxerror();
558 match(GoLexer::OP_COMMA);
559 if (!mustMatch(GoLexer::OP_RPAREN))
561 GoASTCallExpr *call = new GoASTCallExpr(false);
571 GoASTExpr *GoParser::Type2() {
573 case GoLexer::OP_LBRACK:
574 return ArrayOrSliceType(false);
575 case GoLexer::KEYWORD_STRUCT:
577 case GoLexer::KEYWORD_FUNC:
578 return FunctionType();
579 case GoLexer::KEYWORD_INTERFACE:
580 return InterfaceType();
581 case GoLexer::KEYWORD_MAP:
583 case GoLexer::KEYWORD_CHAN:
590 GoASTExpr *GoParser::ArrayOrSliceType(bool allowEllipsis) {
591 Rule r("ArrayType", this);
592 if (match(GoLexer::OP_LBRACK)) {
593 std::unique_ptr<GoASTExpr> len;
594 if (allowEllipsis && match(GoLexer::OP_DOTS)) {
595 len.reset(new GoASTEllipsis(nullptr));
597 len.reset(Expression());
600 if (!match(GoLexer::OP_RBRACK))
602 GoASTExpr *elem = Type();
604 return syntaxerror();
605 return new GoASTArrayType(len.release(), elem);
610 GoASTExpr *GoParser::StructType() {
611 if (!(match(GoLexer::KEYWORD_STRUCT) && mustMatch(GoLexer::OP_LBRACE)))
613 std::unique_ptr<GoASTFieldList> fields(new GoASTFieldList);
614 while (auto *field = FieldDecl())
615 fields->AddList(field);
616 if (!mustMatch(GoLexer::OP_RBRACE))
618 return new GoASTStructType(fields.release());
621 GoASTField *GoParser::FieldDecl() {
622 std::unique_ptr<GoASTField> f(new GoASTField);
623 GoASTExpr *t = FieldNamesAndType(f.get());
625 t = AnonymousFieldType();
629 if (auto *tok = match(GoLexer::LIT_STRING))
630 f->SetTag(new GoASTBasicLit(*tok));
632 return syntaxerror();
636 GoASTExpr *GoParser::FieldNamesAndType(GoASTField *field) {
637 Rule r("FieldNames", this);
638 for (auto *id = Identifier(); id; id = MoreIdentifierList())
642 GoASTExpr *t = Type();
648 GoASTExpr *GoParser::AnonymousFieldType() {
649 bool pointer = match(GoLexer::OP_STAR);
650 GoASTExpr *t = Type();
654 return new GoASTStarExpr(t);
658 GoASTExpr *GoParser::FunctionType() {
659 if (!match(GoLexer::KEYWORD_FUNC))
664 GoASTFuncType *GoParser::Signature() {
665 auto *params = Params();
667 return syntaxerror();
668 auto *result = Params();
670 if (auto *t = Type()) {
671 result = new GoASTFieldList;
672 auto *f = new GoASTField;
677 return new GoASTFuncType(params, result);
680 GoASTFieldList *GoParser::Params() {
681 if (!match(GoLexer::OP_LPAREN))
683 std::unique_ptr<GoASTFieldList> l(new GoASTFieldList);
684 while (GoASTField *p = ParamDecl()) {
686 if (!match(GoLexer::OP_COMMA))
689 if (!mustMatch(GoLexer::OP_RPAREN))
694 GoASTField *GoParser::ParamDecl() {
695 std::unique_ptr<GoASTField> field(new GoASTField);
696 GoASTIdent *id = Identifier();
698 // Try `IdentifierList [ "..." ] Type`.
699 // If that fails, backtrack and try `[ "..." ] Type`.
700 Rule r("NamedParam", this);
701 for (; id; id = MoreIdentifierList())
703 GoASTExpr *t = ParamType();
706 return field.release();
708 field.reset(new GoASTField);
711 GoASTExpr *t = ParamType();
714 return field.release();
719 GoASTExpr *GoParser::ParamType() {
720 bool dots = match(GoLexer::OP_DOTS);
721 GoASTExpr *t = Type();
725 return syntaxerror();
726 return new GoASTEllipsis(t);
729 GoASTExpr *GoParser::InterfaceType() {
730 if (!match(GoLexer::KEYWORD_INTERFACE) || !mustMatch(GoLexer::OP_LBRACE))
732 std::unique_ptr<GoASTFieldList> methods(new GoASTFieldList);
734 Rule r("MethodSpec", this);
735 // ( identifier Signature | TypeName ) ;
736 std::unique_ptr<GoASTIdent> id(Identifier());
739 GoASTExpr *type = Signature();
746 return syntaxerror();
747 auto *f = new GoASTField;
749 f->AddNames(id.release());
753 if (!mustMatch(GoLexer::OP_RBRACE))
755 return new GoASTInterfaceType(methods.release());
758 GoASTExpr *GoParser::MapType() {
759 if (!(match(GoLexer::KEYWORD_MAP) && mustMatch(GoLexer::OP_LBRACK)))
761 std::unique_ptr<GoASTExpr> key(Type());
763 return syntaxerror();
764 if (!mustMatch(GoLexer::OP_RBRACK))
768 return syntaxerror();
769 return new GoASTMapType(key.release(), elem);
772 GoASTExpr *GoParser::ChanType() {
773 Rule r("chan", this);
774 if (match(GoLexer::OP_LT_MINUS)) {
775 if (match(GoLexer::KEYWORD_CHAN)) {
778 return syntaxerror();
779 return new GoASTChanType(GoASTNode::eChanRecv, elem);
786 GoASTExpr *GoParser::ChanType2() {
787 if (!match(GoLexer::KEYWORD_CHAN))
789 auto dir = GoASTNode::eChanBidir;
790 if (match(GoLexer::OP_LT_MINUS))
791 dir = GoASTNode::eChanSend;
794 return syntaxerror();
795 return new GoASTChanType(dir, elem);
798 GoASTExpr *GoParser::Type() {
799 if (GoASTExpr *t = Type2())
801 if (GoASTExpr *t = Name())
803 if (GoASTExpr *t = ChanType())
805 if (match(GoLexer::OP_STAR)) {
806 GoASTExpr *t = Type();
808 return syntaxerror();
809 return new GoASTStarExpr(t);
811 if (match(GoLexer::OP_LPAREN)) {
812 std::unique_ptr<GoASTExpr> t(Type());
813 if (!t || !match(GoLexer::OP_RPAREN))
814 return syntaxerror();
820 bool GoParser::Semicolon() {
821 if (match(GoLexer::OP_SEMICOLON))
824 case GoLexer::OP_RPAREN:
825 case GoLexer::OP_RBRACE:
826 case GoLexer::TOK_EOF:
833 GoASTExpr *GoParser::Name() {
834 if (auto *id = Identifier()) {
835 if (GoASTExpr *qual = QualifiedIdent(id))
842 GoASTExpr *GoParser::QualifiedIdent(lldb_private::GoASTIdent *p) {
843 Rule r("QualifiedIdent", this);
844 llvm::SmallString<32> path(p->GetName().m_value);
845 GoLexer::Token *next;
846 bool have_slashes = false;
847 // LLDB extension: support full/package/path.name
848 while (match(GoLexer::OP_SLASH) && (next = match(GoLexer::TOK_IDENTIFIER))) {
851 path.append(next->m_value);
853 if (match(GoLexer::OP_DOT)) {
854 auto *name = Identifier();
857 p->SetName(GoLexer::Token(GoLexer::TOK_IDENTIFIER, CopyString(path)));
859 return new GoASTSelectorExpr(p, name);
865 llvm::StringRef GoParser::CopyString(llvm::StringRef s) {
866 return m_strings.insert(std::make_pair(s, 'x')).first->getKey();
869 void GoParser::GetError(Status &error) {
870 llvm::StringRef want;
873 m_last_tok == GoLexer::TOK_INVALID ? DescribeToken(m_last_tok) : m_last;
876 size_t len = m_lexer.BytesRemaining();
883 got = m_lexer.GetString(len);
884 error.SetErrorStringWithFormat("Syntax error: expected %s before '%s'.",
885 want.str().c_str(), got.str().c_str());