1 // parse.h -- Go frontend parser. -*- C++ -*-
3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
10 class Set_iota_traverse;
15 class Typed_identifier;
16 class Typed_identifier_list;
20 class Expression_list;
21 class Struct_field_list;
23 class Type_case_clauses;
43 PRECEDENCE_INVALID = -1,
44 PRECEDENCE_NORMAL = 0,
52 // We use this when parsing the range clause of a for statement.
55 // Set to true if we found a range clause.
57 // The index expression.
59 // The value expression.
61 // The range expression.
65 : found(false), index(NULL), value(NULL), range(NULL)
69 // We use this when parsing the statement at the start of a switch,
70 // in order to recognize type switches.
73 // Set to true if we find a type switch.
77 // The location of the variable.
83 : found(false), name(), location(UNKNOWN_LOCATION), expr(NULL)
87 // A variable defined in an enclosing function referenced by the
92 Enclosing_var(Named_object* var, Named_object* in_function,
94 : var_(var), in_function_(in_function), index_(index)
97 // We put these in a vector, so we need a default constructor.
99 : var_(NULL), in_function_(NULL), index_(-1U)
104 { return this->var_; }
108 { return this->in_function_; }
112 { return this->index_; }
115 // The variable which is being referred to.
117 // The function where the variable is defined.
118 Named_object* in_function_;
119 // The index of the field in this function's closure struct for
124 // We store Enclosing_var entries in a set, so we need a comparator.
125 struct Enclosing_var_comparison
128 operator()(const Enclosing_var&, const Enclosing_var&);
131 // A set of Enclosing_var entries.
132 typedef std::set<Enclosing_var, Enclosing_var_comparison> Enclosing_vars;
134 // Used to detect duplicate parameter/result names.
135 typedef std::map<std::string, const Typed_identifier*> Names;
137 // Peek at the current token from the lexer.
141 // Consume the current token, return the next one.
145 // Push a token back on the input stream.
147 unget_token(const Token&);
149 // The location of the current token.
153 // For break and continue we keep a stack of statements with
154 // associated labels (if any). The top of the stack is used for a
155 // break or continue statement with no label.
156 typedef std::vector<std::pair<Statement*, Label*> > Bc_stack;
158 // Parser nonterminals.
159 void identifier_list(Typed_identifier_list*);
160 Expression_list* expression_list(Expression*, bool may_be_sink);
161 bool qualified_ident(std::string*, Named_object**);
163 bool type_may_start_here();
164 Type* type_name(bool issue_error);
165 Type* array_type(bool may_use_ellipsis);
168 void field_decl(Struct_field_list*);
169 Type* pointer_type();
170 Type* channel_type();
171 void check_signature_names(const Typed_identifier_list*, Names*);
172 Function_type* signature(Typed_identifier*, Location);
173 bool parameters(Typed_identifier_list**, bool* is_varargs);
174 Typed_identifier_list* parameter_list(bool* is_varargs);
175 void parameter_decl(bool, Typed_identifier_list*, bool*, bool*);
176 bool result(Typed_identifier_list**);
178 Type* interface_type();
179 void method_spec(Typed_identifier_list*);
181 bool declaration_may_start_here();
182 void decl(void (Parse::*)(void*), void*);
183 void list(void (Parse::*)(void*), void*, bool);
185 void const_spec(Type**, Expression_list**);
187 void type_spec(void*);
189 void var_spec(void*);
190 void init_vars(const Typed_identifier_list*, Type*, Expression_list*,
191 bool is_coloneq, Location);
192 bool init_vars_from_call(const Typed_identifier_list*, Type*, Expression*,
193 bool is_coloneq, Location);
194 bool init_vars_from_map(const Typed_identifier_list*, Type*, Expression*,
195 bool is_coloneq, Location);
196 bool init_vars_from_receive(const Typed_identifier_list*, Type*,
197 Expression*, bool is_coloneq, Location);
198 bool init_vars_from_type_guard(const Typed_identifier_list*, Type*,
199 Expression*, bool is_coloneq,
201 Named_object* init_var(const Typed_identifier&, Type*, Expression*,
202 bool is_coloneq, bool type_from_init, bool* is_new);
203 Named_object* create_dummy_global(Type*, Expression*, Location);
204 void simple_var_decl_or_assignment(const std::string&, Location,
205 Range_clause*, Type_switch*);
206 void function_decl();
207 Typed_identifier* receiver();
208 Expression* operand(bool may_be_sink);
209 Expression* enclosing_var_reference(Named_object*, Named_object*,
211 Expression* composite_lit(Type*, int depth, Location);
212 Expression* function_lit();
213 Expression* create_closure(Named_object* function, Enclosing_vars*,
215 Expression* primary_expr(bool may_be_sink, bool may_be_composite_lit,
216 bool* is_type_switch);
217 Expression* selector(Expression*, bool* is_type_switch);
218 Expression* index(Expression*);
219 Expression* call(Expression*);
220 Expression* expression(Precedence, bool may_be_sink,
221 bool may_be_composite_lit, bool* is_type_switch);
222 bool expression_may_start_here();
223 Expression* unary_expr(bool may_be_sink, bool may_be_composite_lit,
224 bool* is_type_switch);
225 Expression* qualified_expr(Expression*, Location);
226 Expression* id_to_expression(const std::string&, Location);
227 void statement(Label*);
228 bool statement_may_start_here();
229 void labeled_stmt(const std::string&, Location);
230 Expression* simple_stat(bool, bool*, Range_clause*, Type_switch*);
231 bool simple_stat_may_start_here();
232 void statement_list();
233 bool statement_list_may_start_here();
234 void expression_stat(Expression*);
235 void send_stmt(Expression*);
236 void inc_dec_stat(Expression*);
237 void assignment(Expression*, Range_clause*);
238 void tuple_assignment(Expression_list*, Range_clause*);
240 void go_or_defer_stat();
243 void switch_stat(Label*);
244 Statement* expr_switch_body(Label*, Expression*, Location);
245 void expr_case_clause(Case_clauses*, bool* saw_default);
246 Expression_list* expr_switch_case(bool*);
247 Statement* type_switch_body(Label*, const Type_switch&, Location);
248 void type_case_clause(Named_object*, Type_case_clauses*, bool* saw_default);
249 void type_switch_case(std::vector<Type*>*, bool*);
250 void select_stat(Label*);
251 void comm_clause(Select_clauses*, bool* saw_default);
252 bool comm_case(bool*, Expression**, Expression**, Expression**,
253 std::string*, std::string*, bool*);
254 bool send_or_recv_stmt(bool*, Expression**, Expression**, Expression**,
255 std::string*, std::string*);
256 void for_stat(Label*);
257 void for_clause(Expression**, Block**);
258 void range_clause_decl(const Typed_identifier_list*, Range_clause*);
259 void range_clause_expr(const Expression_list*, Range_clause*);
260 void push_break_statement(Statement*, Label*);
261 void push_continue_statement(Statement*, Label*);
262 void pop_break_statement();
263 void pop_continue_statement();
264 Statement* find_bc_statement(const Bc_stack*, const std::string&);
266 void continue_stat();
268 void package_clause();
270 void import_spec(void*);
274 void increment_iota();
276 // Skip past an error looking for a semicolon or OP. Return true if
277 // all is well, false if we found EOF.
279 skip_past_error(Operator op);
281 // Verify that an expression is not a sink, and return either the
282 // expression or an error.
284 verify_not_sink(Expression*);
286 // Return the statement associated with a label in a Bc_stack, or
289 find_bc_statement(const Bc_stack*, const std::string&) const;
291 // The lexer output we are parsing.
293 // The current token.
295 // A token pushed back on the input stream.
297 // Whether unget_token_ is valid.
298 bool unget_token_valid_;
299 // The code we are generating.
301 // A stack of statements for which break may be used.
302 Bc_stack* break_stack_;
303 // A stack of statements for which continue may be used.
304 Bc_stack* continue_stack_;
305 // The current iota value.
307 // References from the local function to variables defined in
308 // enclosing functions.
309 Enclosing_vars enclosing_vars_;
313 #endif // !defined(GO_PARSE_H)