]>
Commit | Line | Data |
---|---|---|
83ffe9cd | 1 | // Copyright (C) 2021-2023 Free Software Foundation, Inc. |
520b52b2 TY |
2 | |
3 | // This file is part of GCC. | |
4 | ||
5 | // GCC is free software; you can redistribute it and/or modify it under | |
6 | // the terms of the GNU General Public License as published by the Free | |
7 | // Software Foundation; either version 3, or (at your option) any later | |
8 | // version. | |
9 | ||
10 | // GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
11 | // WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
13 | // for more details. | |
14 | ||
15 | // You should have received a copy of the GNU General Public License | |
16 | // along with GCC; see the file COPYING3. If not see | |
17 | // <http://www.gnu.org/licenses/>. | |
18 | ||
19 | #ifndef RUST_HIR_SCAN_DEADCODE | |
20 | #define RUST_HIR_SCAN_DEADCODE | |
21 | ||
22 | #include "rust-hir-full-decls.h" | |
23 | #include "rust-hir-map.h" | |
24 | #include "rust-lint-marklive.h" | |
25 | #include "rust-name-resolver.h" | |
26 | #include "rust-diagnostics.h" | |
27 | ||
28 | namespace Rust { | |
29 | namespace Analysis { | |
30 | ||
31 | // Scan item symbols and warn the symbol if it is not in the live_symbols set. | |
32 | // There are three kinds of item we should handle in this pass. | |
33 | // 1. Function item | |
34 | // 2. The function item in the impl block without trait | |
35 | // 3. StructStruct, e.g., `Struct Foo{one: 1, two: 2}`. Furthermore, the unused | |
36 | // struct fields will be warned too. | |
37 | // 4. TupleStruct, e.g., `Struct Foo(i32, i32)` | |
38 | class ScanDeadcode : public MarkLiveBase | |
39 | { | |
40 | using Rust::Analysis::MarkLiveBase::visit; | |
41 | ||
42 | public: | |
43 | static void Scan (HIR::Crate &crate) | |
44 | { | |
45 | std::set<HirId> live_symbols = Analysis::MarkLive::Analysis (crate); | |
46 | ScanDeadcode sdc (live_symbols); | |
47 | for (auto it = crate.items.begin (); it != crate.items.end (); it++) | |
48 | { | |
49 | it->get ()->accept_vis (sdc); | |
50 | } | |
51 | }; | |
52 | ||
53 | void visit (HIR::Function &function) override | |
54 | { | |
55 | HirId hirId = function.get_mappings ().get_hirid (); | |
56 | if (should_warn (hirId)) | |
57 | { | |
58 | if (mappings->is_impl_item (hirId)) | |
59 | { | |
60 | HIR::ImplBlock *implBlock | |
61 | = mappings->lookup_associated_impl (hirId); | |
62 | if (!implBlock->has_trait_ref ()) | |
63 | { | |
64 | rust_warning_at (function.get_locus (), 0, | |
65 | "associated function is never used: %<%s%>", | |
66 | function.get_function_name ().c_str ()); | |
67 | } | |
68 | } | |
69 | else | |
70 | { | |
71 | rust_warning_at (function.get_locus (), 0, | |
72 | "function is never used: %<%s%>", | |
73 | function.get_function_name ().c_str ()); | |
74 | } | |
75 | } | |
76 | } | |
77 | ||
78 | void visit (HIR::StructStruct &stct) override | |
79 | { | |
80 | HirId hirId = stct.get_mappings ().get_hirid (); | |
81 | if (should_warn (hirId)) | |
82 | { | |
83 | bool name_starts_underscore = stct.get_identifier ().at (0) == '_'; | |
84 | if (!name_starts_underscore) | |
85 | rust_warning_at (stct.get_locus (), 0, | |
86 | "struct is never constructed: %<%s%>", | |
87 | stct.get_identifier ().c_str ()); | |
88 | } | |
89 | else | |
90 | { | |
91 | // only warn the unused fields when in unwarned struct. | |
92 | for (auto &field : stct.get_fields ()) | |
93 | { | |
94 | HirId field_hir_id = field.get_mappings ().get_hirid (); | |
95 | if (should_warn (field_hir_id)) | |
96 | { | |
97 | rust_warning_at (field.get_locus (), 0, | |
98 | "field is never read: %<%s%>", | |
99 | field.get_field_name ().c_str ()); | |
100 | } | |
101 | } | |
102 | } | |
103 | } | |
104 | ||
105 | void visit (HIR::TupleStruct &stct) override | |
106 | { | |
107 | // only warn tuple struct unconstructed, and ignoring unused field | |
108 | HirId hirId = stct.get_mappings ().get_hirid (); | |
109 | if (should_warn (hirId)) | |
110 | { | |
111 | rust_warning_at (stct.get_locus (), 0, | |
112 | "struct is never constructed: %<%s%>", | |
113 | stct.get_identifier ().c_str ()); | |
114 | } | |
115 | } | |
116 | ||
117 | void visit (HIR::ImplBlock &blc) override | |
118 | { | |
119 | if (blc.has_impl_items ()) | |
120 | { | |
121 | for (auto &implItem : blc.get_impl_items ()) | |
122 | { | |
123 | implItem->accept_vis (*this); | |
124 | } | |
125 | } | |
126 | } | |
127 | ||
128 | void visit (HIR::Module &mod) override | |
129 | { | |
130 | for (auto &item : mod.get_items ()) | |
131 | item->accept_vis (*this); | |
132 | } | |
133 | ||
134 | private: | |
135 | std::set<HirId> live_symbols; | |
136 | Resolver::Resolver *resolver; | |
137 | Analysis::Mappings *mappings; | |
138 | ||
139 | ScanDeadcode (std::set<HirId> &live_symbols) | |
140 | : live_symbols (live_symbols), resolver (Resolver::Resolver::get ()), | |
141 | mappings (Analysis::Mappings::get ()){}; | |
142 | ||
143 | bool should_warn (HirId hirId) | |
144 | { | |
145 | // TODO: There are more condition to check if should warn, i.e visibility, | |
146 | // attributes. | |
147 | return live_symbols.find (hirId) == live_symbols.end (); | |
148 | } | |
149 | }; | |
150 | ||
151 | } // namespace Analysis | |
152 | } // namespace Rust | |
153 | ||
154 | #endif |