llvm-project/lldb/source/Plugins/ExpressionParser/Go/GoParser.cpp

1036 lines
25 KiB
C++

//===-- GoParser.cpp ---------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <vector>
#include "GoParser.h"
#include "lldb/Core/Error.h"
#include "llvm/ADT/SmallString.h"
#include "Plugins/ExpressionParser/Go/GoAST.h"
using namespace lldb_private;
using namespace lldb;
namespace
{
llvm::StringRef
DescribeToken(GoLexer::TokenType t)
{
switch (t)
{
case GoLexer::TOK_EOF:
return "<eof>";
case GoLexer::TOK_IDENTIFIER:
return "identifier";
case GoLexer::LIT_FLOAT:
return "float";
case GoLexer::LIT_IMAGINARY:
return "imaginary";
case GoLexer::LIT_INTEGER:
return "integer";
case GoLexer::LIT_RUNE:
return "rune";
case GoLexer::LIT_STRING:
return "string";
default:
return GoLexer::LookupToken(t);
}
}
} // namespace
class GoParser::Rule
{
public:
Rule(llvm::StringRef name, GoParser *p) : m_name(name), m_parser(p), m_pos(p->m_pos) {}
std::nullptr_t
error()
{
if (!m_parser->m_failed)
{
// Set m_error in case this is the top level.
if (m_parser->m_last_tok == GoLexer::TOK_INVALID)
m_parser->m_error = m_parser->m_last;
else
m_parser->m_error = DescribeToken(m_parser->m_last_tok);
// And set m_last in case it isn't.
m_parser->m_last = m_name;
m_parser->m_last_tok = GoLexer::TOK_INVALID;
m_parser->m_pos = m_pos;
}
return nullptr;
}
private:
llvm::StringRef m_name;
GoParser *m_parser;
size_t m_pos;
};
GoParser::GoParser(const char *src) : m_lexer(src), m_pos(0), m_failed(false)
{
}
GoASTStmt *
GoParser::Statement()
{
Rule r("Statement", this);
GoLexer::TokenType t = peek();
GoASTStmt *ret = nullptr;
switch (t)
{
case GoLexer::TOK_EOF:
case GoLexer::OP_SEMICOLON:
case GoLexer::OP_RPAREN:
case GoLexer::OP_RBRACE:
case GoLexer::TOK_INVALID:
return EmptyStmt();
case GoLexer::OP_LBRACE:
return Block();
/* TODO:
case GoLexer::KEYWORD_GO:
return GoStmt();
case GoLexer::KEYWORD_RETURN:
return ReturnStmt();
case GoLexer::KEYWORD_BREAK:
case GoLexer::KEYWORD_CONTINUE:
case GoLexer::KEYWORD_GOTO:
case GoLexer::KEYWORD_FALLTHROUGH:
return BranchStmt();
case GoLexer::KEYWORD_IF:
return IfStmt();
case GoLexer::KEYWORD_SWITCH:
return SwitchStmt();
case GoLexer::KEYWORD_SELECT:
return SelectStmt();
case GoLexer::KEYWORD_FOR:
return ForStmt();
case GoLexer::KEYWORD_DEFER:
return DeferStmt();
case GoLexer::KEYWORD_CONST:
case GoLexer::KEYWORD_TYPE:
case GoLexer::KEYWORD_VAR:
return DeclStmt();
case GoLexer::TOK_IDENTIFIER:
if ((ret = LabeledStmt()) ||
(ret = ShortVarDecl()))
{
return ret;
}
*/
default:
break;
}
GoASTExpr *expr = Expression();
if (expr == nullptr)
return r.error();
if (/*(ret = SendStmt(expr)) ||*/
(ret = IncDecStmt(expr)) || (ret = Assignment(expr)) || (ret = ExpressionStmt(expr)))
{
return ret;
}
delete expr;
return r.error();
}
GoASTStmt *
GoParser::ExpressionStmt(GoASTExpr *e)
{
if (Semicolon())
return new GoASTExprStmt(e);
return nullptr;
}
GoASTStmt *
GoParser::IncDecStmt(GoASTExpr *e)
{
Rule r("IncDecStmt", this);
if (match(GoLexer::OP_PLUS_PLUS))
return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_PLUS_PLUS) : r.error();
if (match(GoLexer::OP_MINUS_MINUS))
return Semicolon() ? new GoASTIncDecStmt(e, GoLexer::OP_MINUS_MINUS) : r.error();
return nullptr;
}
GoASTStmt *
GoParser::Assignment(lldb_private::GoASTExpr *e)
{
Rule r("Assignment", this);
std::vector<std::unique_ptr<GoASTExpr>> lhs;
for (GoASTExpr *l = MoreExpressionList(); l; l = MoreExpressionList())
lhs.push_back(std::unique_ptr<GoASTExpr>(l));
switch (peek())
{
case GoLexer::OP_EQ:
case GoLexer::OP_PLUS_EQ:
case GoLexer::OP_MINUS_EQ:
case GoLexer::OP_PIPE_EQ:
case GoLexer::OP_CARET_EQ:
case GoLexer::OP_STAR_EQ:
case GoLexer::OP_SLASH_EQ:
case GoLexer::OP_PERCENT_EQ:
case GoLexer::OP_LSHIFT_EQ:
case GoLexer::OP_RSHIFT_EQ:
case GoLexer::OP_AMP_EQ:
case GoLexer::OP_AMP_CARET_EQ:
break;
default:
return r.error();
}
// We don't want to own e until we know this is an assignment.
std::unique_ptr<GoASTAssignStmt> stmt(new GoASTAssignStmt(false));
stmt->AddLhs(e);
for (auto &l : lhs)
stmt->AddLhs(l.release());
for (GoASTExpr *r = Expression(); r; r = MoreExpressionList())
stmt->AddRhs(r);
if (!Semicolon() || stmt->NumRhs() == 0)
return new GoASTBadStmt;
return stmt.release();
}
GoASTStmt *
GoParser::EmptyStmt()
{
if (match(GoLexer::TOK_EOF))
return nullptr;
if (Semicolon())
return new GoASTEmptyStmt;
return nullptr;
}
GoASTStmt *
GoParser::GoStmt()
{
if (match(GoLexer::KEYWORD_GO))
{
if (GoASTCallExpr *e = llvm::dyn_cast_or_null<GoASTCallExpr>(Expression()))
{
return FinishStmt(new GoASTGoStmt(e));
}
m_last = "call expression";
m_failed = true;
return new GoASTBadStmt();
}
return nullptr;
}
GoASTStmt *
GoParser::ReturnStmt()
{
if (match(GoLexer::KEYWORD_RETURN))
{
std::unique_ptr<GoASTReturnStmt> r(new GoASTReturnStmt());
for (GoASTExpr *e = Expression(); e; e = MoreExpressionList())
r->AddResults(e);
return FinishStmt(r.release());
}
return nullptr;
}
GoASTStmt *
GoParser::BranchStmt()
{
GoLexer::Token *tok;
if ((tok = match(GoLexer::KEYWORD_BREAK)) || (tok = match(GoLexer::KEYWORD_CONTINUE)) ||
(tok = match(GoLexer::KEYWORD_GOTO)))
{
auto *e = Identifier();
if (tok->m_type == GoLexer::KEYWORD_GOTO && !e)
return syntaxerror();
return FinishStmt(new GoASTBranchStmt(e, tok->m_type));
}
if ((tok = match(GoLexer::KEYWORD_FALLTHROUGH)))
return FinishStmt(new GoASTBranchStmt(nullptr, tok->m_type));
return nullptr;
}
GoASTIdent *
GoParser::Identifier()
{
if (auto *tok = match(GoLexer::TOK_IDENTIFIER))
return new GoASTIdent(*tok);
return nullptr;
}
GoASTExpr *
GoParser::MoreExpressionList()
{
if (match(GoLexer::OP_COMMA))
{
auto *e = Expression();
if (!e)
return syntaxerror();
return e;
}
return nullptr;
}
GoASTIdent *
GoParser::MoreIdentifierList()
{
if (match(GoLexer::OP_COMMA))
{
auto *i = Identifier();
if (!i)
return syntaxerror();
return i;
}
return nullptr;
}
GoASTExpr *
GoParser::Expression()
{
Rule r("Expression", this);
if (GoASTExpr *ret = OrExpr())
return ret;
return r.error();
}
GoASTExpr *
GoParser::UnaryExpr()
{
switch (peek())
{
case GoLexer::OP_PLUS:
case GoLexer::OP_MINUS:
case GoLexer::OP_BANG:
case GoLexer::OP_CARET:
case GoLexer::OP_STAR:
case GoLexer::OP_AMP:
case GoLexer::OP_LT_MINUS:
{
const GoLexer::Token t = next();
if (GoASTExpr *e = UnaryExpr())
{
if (t.m_type == GoLexer::OP_STAR)
return new GoASTStarExpr(e);
else
return new GoASTUnaryExpr(t.m_type, e);
}
return syntaxerror();
}
default:
return PrimaryExpr();
}
}
GoASTExpr *
GoParser::OrExpr()
{
std::unique_ptr<GoASTExpr> l(AndExpr());
if (l)
{
while (match(GoLexer::OP_PIPE_PIPE))
{
GoASTExpr *r = AndExpr();
if (r)
l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_PIPE_PIPE));
else
return syntaxerror();
}
return l.release();
}
return nullptr;
}
GoASTExpr *
GoParser::AndExpr()
{
std::unique_ptr<GoASTExpr> l(RelExpr());
if (l)
{
while (match(GoLexer::OP_AMP_AMP))
{
GoASTExpr *r = RelExpr();
if (r)
l.reset(new GoASTBinaryExpr(l.release(), r, GoLexer::OP_AMP_AMP));
else
return syntaxerror();
}
return l.release();
}
return nullptr;
}
GoASTExpr *
GoParser::RelExpr()
{
std::unique_ptr<GoASTExpr> l(AddExpr());
if (l)
{
for (GoLexer::Token *t; (t = match(GoLexer::OP_EQ_EQ)) || (t = match(GoLexer::OP_BANG_EQ)) ||
(t = match(GoLexer::OP_LT)) || (t = match(GoLexer::OP_LT_EQ)) ||
(t = match(GoLexer::OP_GT)) || (t = match(GoLexer::OP_GT_EQ));)
{
GoLexer::TokenType op = t->m_type;
GoASTExpr *r = AddExpr();
if (r)
l.reset(new GoASTBinaryExpr(l.release(), r, op));
else
return syntaxerror();
}
return l.release();
}
return nullptr;
}
GoASTExpr *
GoParser::AddExpr()
{
std::unique_ptr<GoASTExpr> l(MulExpr());
if (l)
{
for (GoLexer::Token *t; (t = match(GoLexer::OP_PLUS)) || (t = match(GoLexer::OP_MINUS)) ||
(t = match(GoLexer::OP_PIPE)) || (t = match(GoLexer::OP_CARET));)
{
GoLexer::TokenType op = t->m_type;
GoASTExpr *r = MulExpr();
if (r)
l.reset(new GoASTBinaryExpr(l.release(), r, op));
else
return syntaxerror();
}
return l.release();
}
return nullptr;
}
GoASTExpr *
GoParser::MulExpr()
{
std::unique_ptr<GoASTExpr> l(UnaryExpr());
if (l)
{
for (GoLexer::Token *t; (t = match(GoLexer::OP_STAR)) || (t = match(GoLexer::OP_SLASH)) ||
(t = match(GoLexer::OP_PERCENT)) || (t = match(GoLexer::OP_LSHIFT)) ||
(t = match(GoLexer::OP_RSHIFT)) || (t = match(GoLexer::OP_AMP)) ||
(t = match(GoLexer::OP_AMP_CARET));)
{
GoLexer::TokenType op = t->m_type;
GoASTExpr *r = UnaryExpr();
if (r)
l.reset(new GoASTBinaryExpr(l.release(), r, op));
else
return syntaxerror();
}
return l.release();
}
return nullptr;
}
GoASTExpr *
GoParser::PrimaryExpr()
{
GoASTExpr *l;
GoASTExpr *r;
(l = Conversion()) || (l = Operand());
if (!l)
return nullptr;
while ((r = Selector(l)) || (r = IndexOrSlice(l)) || (r = TypeAssertion(l)) || (r = Arguments(l)))
{
l = r;
}
return l;
}
GoASTExpr *
GoParser::Operand()
{
GoLexer::Token *lit;
if ((lit = match(GoLexer::LIT_INTEGER)) || (lit = match(GoLexer::LIT_FLOAT)) ||
(lit = match(GoLexer::LIT_IMAGINARY)) || (lit = match(GoLexer::LIT_RUNE)) || (lit = match(GoLexer::LIT_STRING)))
return new GoASTBasicLit(*lit);
if (match(GoLexer::OP_LPAREN))
{
GoASTExpr *e;
if (!((e = Expression()) && match(GoLexer::OP_RPAREN)))
return syntaxerror();
return e;
}
// MethodExpr should be handled by Selector
if (GoASTExpr *e = CompositeLit())
return e;
if (GoASTExpr *n = Name())
return n;
return FunctionLit();
}
GoASTExpr *
GoParser::FunctionLit()
{
if (!match(GoLexer::KEYWORD_FUNC))
return nullptr;
auto *sig = Signature();
if (!sig)
return syntaxerror();
auto *body = Block();
if (!body)
{
delete sig;
return syntaxerror();
}
return new GoASTFuncLit(sig, body);
}
GoASTBlockStmt *
GoParser::Block()
{
if (!match(GoLexer::OP_LBRACE))
return nullptr;
std::unique_ptr<GoASTBlockStmt> block(new GoASTBlockStmt);
for (auto *s = Statement(); s; s = Statement())
block->AddList(s);
if (!match(GoLexer::OP_RBRACE))
return syntaxerror();
return block.release();
}
GoASTExpr *
GoParser::CompositeLit()
{
Rule r("CompositeLit", this);
GoASTExpr *type;
(type = StructType()) || (type = ArrayOrSliceType(true)) || (type = MapType()) || (type = Name());
if (!type)
return r.error();
GoASTCompositeLit *lit = LiteralValue();
if (!lit)
return r.error();
lit->SetType(type);
return lit;
}
GoASTCompositeLit *
GoParser::LiteralValue()
{
if (!match(GoLexer::OP_LBRACE))
return nullptr;
std::unique_ptr<GoASTCompositeLit> lit(new GoASTCompositeLit);
for (GoASTExpr *e = Element(); e; e = Element())
{
lit->AddElts(e);
if (!match(GoLexer::OP_COMMA))
break;
}
if (!mustMatch(GoLexer::OP_RBRACE))
return nullptr;
return lit.release();
}
GoASTExpr *
GoParser::Element()
{
GoASTExpr *key;
if (!((key = Expression()) || (key = LiteralValue())))
return nullptr;
if (!match(GoLexer::OP_COLON))
return key;
GoASTExpr *value;
if ((value = Expression()) || (value = LiteralValue()))
return new GoASTKeyValueExpr(key, value);
delete key;
return syntaxerror();
}
GoASTExpr *
GoParser::Selector(GoASTExpr *e)
{
Rule r("Selector", this);
if (match(GoLexer::OP_DOT))
{
if (auto *name = Identifier())
return new GoASTSelectorExpr(e, name);
}
return r.error();
}
GoASTExpr *
GoParser::IndexOrSlice(GoASTExpr *e)
{
Rule r("IndexOrSlice", this);
if (match(GoLexer::OP_LBRACK))
{
std::unique_ptr<GoASTExpr> i1(Expression()), i2, i3;
bool slice = false;
if (match(GoLexer::OP_COLON))
{
slice = true;
i2.reset(Expression());
if (i2 && match(GoLexer::OP_COLON))
{
i3.reset(Expression());
if (!i3)
return syntaxerror();
}
}
if (!(slice || i1))
return syntaxerror();
if (!mustMatch(GoLexer::OP_RBRACK))
return nullptr;
if (slice)
{
bool slice3 = i3.get();
return new GoASTSliceExpr(e, i1.release(), i2.release(), i3.release(), slice3);
}
return new GoASTIndexExpr(e, i1.release());
}
return r.error();
}
GoASTExpr *
GoParser::TypeAssertion(GoASTExpr *e)
{
Rule r("TypeAssertion", this);
if (match(GoLexer::OP_DOT) && match(GoLexer::OP_LPAREN))
{
if (auto *t = Type())
{
if (!mustMatch(GoLexer::OP_RPAREN))
return nullptr;
return new GoASTTypeAssertExpr(e, t);
}
return syntaxerror();
}
return r.error();
}
GoASTExpr *
GoParser::Arguments(GoASTExpr *e)
{
if (match(GoLexer::OP_LPAREN))
{
std::unique_ptr<GoASTCallExpr> call(new GoASTCallExpr(false));
GoASTExpr *arg;
// ( ExpressionList | Type [ "," ExpressionList ] )
for ((arg = Expression()) || (arg = Type()); arg; arg = MoreExpressionList())
{
call->AddArgs(arg);
}
if (match(GoLexer::OP_DOTS))
call->SetEllipsis(true);
// Eat trailing comma
match(GoLexer::OP_COMMA);
if (!mustMatch(GoLexer::OP_RPAREN))
return nullptr;
call->SetFun(e);
return call.release();
}
return nullptr;
}
GoASTExpr *
GoParser::Conversion()
{
Rule r("Conversion", this);
if (GoASTExpr *t = Type2())
{
if (match(GoLexer::OP_LPAREN))
{
GoASTExpr *v = Expression();
if (!v)
return syntaxerror();
match(GoLexer::OP_COMMA);
if (!mustMatch(GoLexer::OP_RPAREN))
return r.error();
GoASTCallExpr *call = new GoASTCallExpr(false);
call->SetFun(t);
call->AddArgs(v);
return call;
}
}
return r.error();
}
GoASTExpr *
GoParser::Type2()
{
switch (peek())
{
case GoLexer::OP_LBRACK:
return ArrayOrSliceType(false);
case GoLexer::KEYWORD_STRUCT:
return StructType();
case GoLexer::KEYWORD_FUNC:
return FunctionType();
case GoLexer::KEYWORD_INTERFACE:
return InterfaceType();
case GoLexer::KEYWORD_MAP:
return MapType();
case GoLexer::KEYWORD_CHAN:
return ChanType2();
default:
return nullptr;
}
}
GoASTExpr *
GoParser::ArrayOrSliceType(bool allowEllipsis)
{
Rule r("ArrayType", this);
if (match(GoLexer::OP_LBRACK))
{
std::unique_ptr<GoASTExpr> len;
if (allowEllipsis && match(GoLexer::OP_DOTS))
{
len.reset(new GoASTEllipsis(nullptr));
}
else
{
len.reset(Expression());
}
if (!match(GoLexer::OP_RBRACK))
return r.error();
GoASTExpr *elem = Type();
if (!elem)
return syntaxerror();
return new GoASTArrayType(len.release(), elem);
}
return r.error();
}
GoASTExpr *
GoParser::StructType()
{
if (!(match(GoLexer::KEYWORD_STRUCT) && mustMatch(GoLexer::OP_LBRACE)))
return nullptr;
std::unique_ptr<GoASTFieldList> fields(new GoASTFieldList);
while (auto *field = FieldDecl())
fields->AddList(field);
if (!mustMatch(GoLexer::OP_RBRACE))
return nullptr;
return new GoASTStructType(fields.release());
}
GoASTField *
GoParser::FieldDecl()
{
std::unique_ptr<GoASTField> f(new GoASTField);
GoASTExpr *t = FieldNamesAndType(f.get());
if (!t)
t = AnonymousFieldType();
if (!t)
return nullptr;
if (auto *tok = match(GoLexer::LIT_STRING))
f->SetTag(new GoASTBasicLit(*tok));
if (!Semicolon())
return syntaxerror();
return f.release();
}
GoASTExpr *
GoParser::FieldNamesAndType(GoASTField *field)
{
Rule r("FieldNames", this);
for (auto *id = Identifier(); id; id = MoreIdentifierList())
field->AddNames(id);
if (m_failed)
return nullptr;
GoASTExpr *t = Type();
if (t)
return t;
return r.error();
}
GoASTExpr *
GoParser::AnonymousFieldType()
{
bool pointer = match(GoLexer::OP_STAR);
GoASTExpr *t = Type();
if (!t)
return nullptr;
if (pointer)
return new GoASTStarExpr(t);
return t;
}
GoASTExpr *
GoParser::FunctionType()
{
if (!match(GoLexer::KEYWORD_FUNC))
return nullptr;
return Signature();
}
GoASTFuncType *
GoParser::Signature()
{
auto *params = Params();
if (!params)
return syntaxerror();
auto *result = Params();
if (!result)
{
if (auto *t = Type())
{
result = new GoASTFieldList;
auto *f = new GoASTField;
f->SetType(t);
result->AddList(f);
}
}
return new GoASTFuncType(params, result);
}
GoASTFieldList *
GoParser::Params()
{
if (!match(GoLexer::OP_LPAREN))
return nullptr;
std::unique_ptr<GoASTFieldList> l(new GoASTFieldList);
while (GoASTField *p = ParamDecl())
{
l->AddList(p);
if (!match(GoLexer::OP_COMMA))
break;
}
if (!mustMatch(GoLexer::OP_RPAREN))
return nullptr;
return l.release();
}
GoASTField *
GoParser::ParamDecl()
{
std::unique_ptr<GoASTField> field(new GoASTField);
GoASTIdent *id = Identifier();
if (id)
{
// Try `IdentifierList [ "..." ] Type`.
// If that fails, backtrack and try `[ "..." ] Type`.
Rule r("NamedParam", this);
for (; id; id = MoreIdentifierList())
field->AddNames(id);
GoASTExpr *t = ParamType();
if (t)
{
field->SetType(t);
return field.release();
}
field.reset(new GoASTField);
r.error();
}
GoASTExpr *t = ParamType();
if (t)
{
field->SetType(t);
return field.release();
}
return nullptr;
}
GoASTExpr *
GoParser::ParamType()
{
bool dots = match(GoLexer::OP_DOTS);
GoASTExpr *t = Type();
if (!dots)
return t;
if (!t)
return syntaxerror();
return new GoASTEllipsis(t);
}
GoASTExpr *
GoParser::InterfaceType()
{
if (!match(GoLexer::KEYWORD_INTERFACE) || !mustMatch(GoLexer::OP_LBRACE))
return nullptr;
std::unique_ptr<GoASTFieldList> methods(new GoASTFieldList);
while (true)
{
Rule r("MethodSpec", this);
// ( identifier Signature | TypeName ) ;
std::unique_ptr<GoASTIdent> id(Identifier());
if (!id)
break;
GoASTExpr *type = Signature();
if (!type)
{
r.error();
id.reset();
type = Name();
}
if (!Semicolon())
return syntaxerror();
auto *f = new GoASTField;
if (id)
f->AddNames(id.release());
f->SetType(type);
methods->AddList(f);
}
if (!mustMatch(GoLexer::OP_RBRACE))
return nullptr;
return new GoASTInterfaceType(methods.release());
}
GoASTExpr *
GoParser::MapType()
{
if (!(match(GoLexer::KEYWORD_MAP) && mustMatch(GoLexer::OP_LBRACK)))
return nullptr;
std::unique_ptr<GoASTExpr> key(Type());
if (!key)
return syntaxerror();
if (!mustMatch(GoLexer::OP_RBRACK))
return nullptr;
auto *elem = Type();
if (!elem)
return syntaxerror();
return new GoASTMapType(key.release(), elem);
}
GoASTExpr *
GoParser::ChanType()
{
Rule r("chan", this);
if (match(GoLexer::OP_LT_MINUS))
{
if (match(GoLexer::KEYWORD_CHAN))
{
auto *elem = Type();
if (!elem)
return syntaxerror();
return new GoASTChanType(GoASTNode::eChanRecv, elem);
}
return r.error();
}
return ChanType2();
}
GoASTExpr *
GoParser::ChanType2()
{
if (!match(GoLexer::KEYWORD_CHAN))
return nullptr;
auto dir = GoASTNode::eChanBidir;
if (match(GoLexer::OP_LT_MINUS))
dir = GoASTNode::eChanSend;
auto *elem = Type();
if (!elem)
return syntaxerror();
return new GoASTChanType(dir, elem);
}
GoASTExpr *
GoParser::Type()
{
if (GoASTExpr *t = Type2())
return t;
if (GoASTExpr *t = Name())
return t;
if (GoASTExpr *t = ChanType())
return t;
if (match(GoLexer::OP_STAR))
{
GoASTExpr *t = Type();
if (!t)
return syntaxerror();
return new GoASTStarExpr(t);
}
if (match(GoLexer::OP_LPAREN))
{
std::unique_ptr<GoASTExpr> t(Type());
if (!t || !match(GoLexer::OP_RPAREN))
return syntaxerror();
return t.release();
}
return nullptr;
}
bool
GoParser::Semicolon()
{
if (match(GoLexer::OP_SEMICOLON))
return true;
switch (peek())
{
case GoLexer::OP_RPAREN:
case GoLexer::OP_RBRACE:
case GoLexer::TOK_EOF:
return true;
default:
return false;
}
}
GoASTExpr *
GoParser::Name()
{
if (auto *id = Identifier())
{
if (GoASTExpr *qual = QualifiedIdent(id))
return qual;
return id;
}
return nullptr;
}
GoASTExpr *
GoParser::QualifiedIdent(lldb_private::GoASTIdent *p)
{
Rule r("QualifiedIdent", this);
llvm::SmallString<32> path(p->GetName().m_value);
GoLexer::Token *next;
bool have_slashes = false;
// LLDB extension: support full/package/path.name
while (match(GoLexer::OP_SLASH) && (next = match(GoLexer::TOK_IDENTIFIER)))
{
have_slashes = true;
path.append("/");
path.append(next->m_value);
}
if (match(GoLexer::OP_DOT))
{
auto *name = Identifier();
if (name)
{
if (have_slashes)
{
p->SetName(GoLexer::Token(GoLexer::TOK_IDENTIFIER, CopyString(path)));
}
return new GoASTSelectorExpr(p, name);
}
}
return r.error();
}
llvm::StringRef
GoParser::CopyString(llvm::StringRef s)
{
return m_strings.insert(std::make_pair(s, 'x')).first->getKey();
}
void
GoParser::GetError(Error &error)
{
llvm::StringRef want;
if (m_failed)
want = m_last_tok == GoLexer::TOK_INVALID ? DescribeToken(m_last_tok) : m_last;
else
want = m_error;
size_t len = m_lexer.BytesRemaining();
if (len > 10)
len = 10;
llvm::StringRef got;
if (len == 0)
got = "<eof>";
else
got = m_lexer.GetString(len);
error.SetErrorStringWithFormat("Syntax error: expected %s before '%s'.", want.str().c_str(), got.str().c_str());
}