Line data Source code
1 : /* This file is part of GCC.
2 :
3 : GCC is free software; you can redistribute it and/or modify
4 : it under the terms of the GNU General Public License as published by
5 : the Free Software Foundation; either version 3, or (at your option)
6 : any later version.
7 :
8 : GCC is distributed in the hope that it will be useful,
9 : but WITHOUT ANY WARRANTY; without even the implied warranty of
10 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 : GNU General Public License for more details.
12 :
13 : You should have received a copy of the GNU General Public License
14 : along with GCC; see the file COPYING3. If not see
15 : <http://www.gnu.org/licenses/>. */
16 :
17 : #include "rust-parse.h"
18 : #include "rust-linemap.h"
19 : #include "rust-diagnostics.h"
20 : #include "rust-token.h"
21 : #include "rust-attribute-values.h"
22 :
23 : namespace Rust {
24 :
25 : std::string
26 1308 : extract_module_path (const AST::AttrVec &inner_attrs,
27 : const AST::AttrVec &outer_attrs, const std::string &name)
28 : {
29 1308 : AST::Attribute path_attr = AST::Attribute::create_empty ();
30 1407 : for (const auto &attr : inner_attrs)
31 : {
32 101 : if (attr.get_path ().as_string () == Values::Attributes::PATH)
33 : {
34 2 : path_attr = attr;
35 2 : break;
36 : }
37 : }
38 :
39 : // Here, we found a path attribute, but it has no associated string. This is
40 : // invalid
41 1308 : if (!path_attr.is_empty () && !path_attr.has_attr_input ())
42 : {
43 0 : rust_error_at (
44 : path_attr.get_locus (),
45 : "path attributes must contain a filename: %<#[path = \"file\"]%>");
46 0 : return name;
47 : }
48 :
49 1414 : for (const auto &attr : outer_attrs)
50 : {
51 169 : if (attr.get_path ().as_string () == Values::Attributes::PATH)
52 : {
53 63 : path_attr = attr;
54 63 : break;
55 : }
56 : }
57 :
58 : // We didn't find a path attribute. This is not an error, there simply isn't
59 : // one present
60 1308 : if (path_attr.is_empty ())
61 1244 : return name;
62 :
63 : // Here, we found a path attribute, but it has no associated string. This is
64 : // invalid
65 64 : if (!path_attr.has_attr_input ())
66 : {
67 7 : rust_error_at (
68 : path_attr.get_locus (),
69 : "path attributes must contain a filename: %<#[path = \"file\"]%>");
70 7 : return name;
71 : }
72 :
73 57 : auto path_value = path_attr.get_attr_input ().as_string ();
74 :
75 : // At this point, the 'path' is of the following format: '= "<file.rs>"'
76 : // We need to remove the equal sign and only keep the actual filename.
77 : // In order to do this, we can simply go through the string until we find
78 : // a character that is not an equal sign or whitespace
79 57 : auto filename_begin = path_value.find_first_not_of ("=\t ");
80 :
81 : // If the path consists of only whitespace, then we have an error
82 57 : if (filename_begin == std::string::npos)
83 : {
84 14 : rust_error_at (
85 : path_attr.get_locus (),
86 : "path attributes must contain a filename: %<#[path = \"file\"]%>");
87 14 : return name;
88 : }
89 :
90 43 : auto path = path_value.substr (filename_begin);
91 :
92 : // On windows, the path might mix '/' and '\' separators. Replace the
93 : // UNIX-like separators by MSDOS separators to make sure the path will resolve
94 : // properly.
95 : //
96 : // Source: rustc compiler
97 : // (https://github.com/rust-lang/rust/blob/9863bf51a52b8e61bcad312f81b5193d53099f9f/compiler/rustc_expand/src/module.rs#L174)
98 : #if defined(HAVE_DOS_BASED_FILE_SYSTEM)
99 : std::replace (path.begin (), path.end (), '/', '\\');
100 : #endif /* HAVE_DOS_BASED_FILE_SYSTEM */
101 :
102 43 : return path;
103 100 : }
104 :
105 : template <typename T>
106 : static bool
107 189 : contains (std::vector<T> &vec, T elm)
108 : {
109 198 : return std::find (vec.begin (), vec.end (), elm) != vec.end ();
110 : }
111 :
112 : /**
113 : * Avoid UB by calling .front() and .back() on empty containers...
114 : */
115 :
116 : template <typename T>
117 : static const T *
118 22 : get_back_ptr (const std::vector<std::unique_ptr<T>> &values)
119 : {
120 22 : if (values.empty ())
121 : return nullptr;
122 :
123 22 : return values.back ().get ();
124 : }
125 :
126 : template <typename T>
127 : static const T *
128 0 : get_front_ptr (const std::vector<std::unique_ptr<T>> &values)
129 : {
130 22 : if (values.empty ())
131 : return nullptr;
132 :
133 22 : return values.front ().get ();
134 : }
135 :
136 : static bool
137 4 : peculiar_fragment_match_compatible_fragment (
138 : const AST::MacroFragSpec &last_spec, const AST::MacroFragSpec &spec,
139 : location_t match_locus)
140 : {
141 4 : static std::unordered_map<AST::MacroFragSpec::Kind,
142 : std::vector<AST::MacroFragSpec::Kind>>
143 : fragment_follow_set
144 : = {{AST::MacroFragSpec::PATH, {AST::MacroFragSpec::BLOCK}},
145 4 : {AST::MacroFragSpec::TY, {AST::MacroFragSpec::BLOCK}},
146 4 : {AST::MacroFragSpec::VIS,
147 : {AST::MacroFragSpec::IDENT, AST::MacroFragSpec::TY,
148 20 : AST::MacroFragSpec::PATH}}};
149 :
150 4 : auto is_valid
151 4 : = contains (fragment_follow_set[last_spec.get_kind ()], spec.get_kind ());
152 :
153 4 : if (!is_valid)
154 1 : rust_error_at (match_locus,
155 : "fragment specifier %qs is not allowed after %qs fragments",
156 2 : spec.as_string ().c_str (), last_spec.as_string ().c_str ());
157 :
158 4 : return is_valid;
159 : }
160 :
161 : static bool
162 218 : peculiar_fragment_match_compatible (const AST::MacroMatchFragment &last_match,
163 : const AST::MacroMatch &match)
164 : {
165 218 : static std::unordered_map<AST::MacroFragSpec::Kind, std::vector<TokenId>>
166 : follow_set
167 : = {{AST::MacroFragSpec::EXPR, {MATCH_ARROW, COMMA, SEMICOLON}},
168 138 : {AST::MacroFragSpec::STMT, {MATCH_ARROW, COMMA, SEMICOLON}},
169 138 : {AST::MacroFragSpec::PAT, {MATCH_ARROW, COMMA, EQUAL, PIPE, IF, IN}},
170 138 : {AST::MacroFragSpec::PATH,
171 : {MATCH_ARROW, COMMA, EQUAL, PIPE, SEMICOLON, COLON, RIGHT_ANGLE,
172 : RIGHT_SHIFT, LEFT_SQUARE, LEFT_CURLY, AS, WHERE}},
173 138 : {AST::MacroFragSpec::TY,
174 : {MATCH_ARROW, COMMA, EQUAL, PIPE, SEMICOLON, COLON, RIGHT_ANGLE,
175 : RIGHT_SHIFT, LEFT_SQUARE, LEFT_CURLY, AS, WHERE}},
176 138 : {AST::MacroFragSpec::VIS,
177 : {COMMA,
178 : IDENTIFIER,
179 : LEFT_PAREN,
180 : LEFT_SQUARE,
181 : EXCLAM,
182 : ASTERISK,
183 : AMP,
184 : LOGICAL_AND,
185 : QUESTION_MARK,
186 : LIFETIME,
187 : LEFT_ANGLE,
188 : LEFT_SHIFT,
189 : UNDERSCORE,
190 : ABSTRACT,
191 : AS,
192 : ASYNC,
193 : AUTO,
194 : BECOME,
195 : BOX,
196 : BREAK,
197 : CONST,
198 : CONTINUE,
199 : CRATE,
200 : DO,
201 : DYN,
202 : ELSE,
203 : ENUM_KW,
204 : EXTERN_KW,
205 : FALSE_LITERAL,
206 : FINAL_KW,
207 : FN_KW,
208 : FOR,
209 : IF,
210 : IMPL,
211 : IN,
212 : LET,
213 : LOOP,
214 : MACRO,
215 : MATCH_KW,
216 : MOD,
217 : MOVE,
218 : MUT,
219 : OVERRIDE_KW,
220 : PUB,
221 : REF,
222 : RETURN_KW,
223 : SELF_ALIAS,
224 : SELF,
225 : STATIC_KW,
226 : STRUCT_KW,
227 : SUPER,
228 : TRAIT,
229 : TRUE_LITERAL,
230 : TRY,
231 : TYPE,
232 : TYPEOF,
233 : UNSAFE,
234 : UNSIZED,
235 : USE,
236 : VIRTUAL,
237 : WHERE,
238 : WHILE,
239 1184 : YIELD}}};
240 :
241 218 : location_t error_locus = match.get_match_locus ();
242 218 : std::string kind_str = "fragment";
243 218 : auto &allowed_toks = follow_set[last_match.get_frag_spec ().get_kind ()];
244 :
245 : // There are two behaviors to handle here: If the follow-up match is a token,
246 : // we want to check if it is allowed.
247 : // If it is a fragment, repetition or matcher then we know that it will be
248 : // an error.
249 : // For repetitions and matchers we want to extract a proper location to report
250 : // the error.
251 218 : switch (match.get_macro_match_type ())
252 : {
253 189 : case AST::MacroMatch::Tok:
254 189 : {
255 189 : auto tok = static_cast<const AST::Token *> (&match);
256 378 : if (contains (allowed_toks, tok->get_id ()))
257 : return true;
258 8 : kind_str = "token `"
259 16 : + std::string (get_token_description (tok->get_id ())) + "`";
260 8 : error_locus = tok->get_match_locus ();
261 8 : break;
262 : }
263 : break;
264 22 : case AST::MacroMatch::Repetition:
265 22 : {
266 22 : auto repetition
267 : = static_cast<const AST::MacroMatchRepetition *> (&match);
268 22 : auto &matches = repetition->get_matches ();
269 22 : auto first_frag = get_front_ptr (matches);
270 22 : if (first_frag)
271 22 : return peculiar_fragment_match_compatible (last_match, *first_frag);
272 : break;
273 : }
274 1 : case AST::MacroMatch::Matcher:
275 1 : {
276 1 : auto matcher = static_cast<const AST::MacroMatcher *> (&match);
277 1 : auto first_token = matcher->get_delim_type ();
278 1 : TokenId delim_id;
279 1 : switch (first_token)
280 : {
281 : case AST::PARENS:
282 : delim_id = LEFT_PAREN;
283 : break;
284 : case AST::SQUARE:
285 : delim_id = LEFT_SQUARE;
286 : break;
287 : case AST::CURLY:
288 : delim_id = LEFT_CURLY;
289 : break;
290 0 : default:
291 0 : rust_unreachable ();
292 1 : break;
293 : }
294 2 : if (contains (allowed_toks, delim_id))
295 : return true;
296 2 : kind_str = "token `" + std::string (get_token_description (delim_id))
297 1 : + "` at start of matcher";
298 1 : error_locus = matcher->get_match_locus ();
299 1 : break;
300 : }
301 6 : case AST::MacroMatch::Fragment:
302 6 : {
303 6 : auto last_spec = last_match.get_frag_spec ();
304 6 : auto fragment = static_cast<const AST::MacroMatchFragment *> (&match);
305 6 : if (last_spec.has_follow_set_fragment_restrictions ())
306 4 : return peculiar_fragment_match_compatible_fragment (
307 8 : last_spec, fragment->get_frag_spec (), match.get_match_locus ());
308 : }
309 2 : break;
310 : }
311 :
312 11 : rust_error_at (error_locus, "%s is not allowed after %qs fragment",
313 : kind_str.c_str (),
314 11 : last_match.get_frag_spec ().as_string ().c_str ());
315 11 : auto allowed_toks_str
316 22 : = "`" + std::string (get_token_description (allowed_toks[0])) + "`";
317 93 : for (size_t i = 1; i < allowed_toks.size (); i++)
318 82 : allowed_toks_str
319 246 : += ", `" + std::string (get_token_description (allowed_toks[i])) + "`";
320 :
321 11 : rust_inform (error_locus, "allowed tokens are %s", allowed_toks_str.c_str ());
322 :
323 11 : return false;
324 11 : }
325 :
326 : bool
327 583 : is_match_compatible (const AST::MacroMatch &last_match,
328 : const AST::MacroMatch &match)
329 : {
330 605 : const AST::MacroMatch *new_last = nullptr;
331 :
332 : // We want to "extract" the concerning matches. In cases such as matchers and
333 : // repetitions, we actually store multiple matchers, but are only concerned
334 : // about the follow-set ambiguities of certain elements.
335 : // There are some cases where we can short-circuit the algorithm: There will
336 : // never be restrictions on token literals, or on certain fragments which do
337 : // not have a set of follow-restrictions.
338 :
339 605 : switch (last_match.get_macro_match_type ())
340 : {
341 : // This is our main stop condition: When we are finally looking at the
342 : // last match (or its actual last component), and it is a fragment, it
343 : // may contain some follow up restrictions.
344 250 : case AST::MacroMatch::Fragment:
345 250 : {
346 250 : auto fragment
347 : = static_cast<const AST::MacroMatchFragment *> (&last_match);
348 250 : if (fragment->get_frag_spec ().has_follow_set_restrictions ())
349 196 : return peculiar_fragment_match_compatible (*fragment, match);
350 : else
351 : return true;
352 : }
353 22 : case AST::MacroMatch::Repetition:
354 22 : {
355 : // A repetition on the left hand side means we want to make sure the
356 : // last match of the repetition is compatible with the new match
357 22 : auto repetition
358 : = static_cast<const AST::MacroMatchRepetition *> (&last_match);
359 22 : new_last = get_back_ptr (repetition->get_matches ());
360 : // If there are no matches in the matcher, then it can be followed by
361 : // anything
362 22 : if (!new_last)
363 : return true;
364 : break;
365 : }
366 : case AST::MacroMatch::Matcher:
367 : case AST::MacroMatch::Tok:
368 : return true;
369 : }
370 :
371 0 : rust_assert (new_last);
372 :
373 : // We check recursively until we find a terminating condition
374 : // FIXME: Does expansion depth/limit matter here?
375 : return is_match_compatible (*new_last, match);
376 : }
377 : } // namespace Rust
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