[go: up one dir, main page]

gimli 0.10.0

A zero-copy DWARF debugging format parser.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
#![feature(test)]

extern crate gimli;
extern crate test;

use gimli::{DebugAbbrev, DebugAranges, DebugInfo, DebugLine, DebugLineOffset, DebugPubNames,
            DebugPubTypes, LittleEndian, EntriesTreeIter};
use std::env;
use std::fs::File;
use std::io::Read;
use std::path::PathBuf;

pub fn read_section(section: &str) -> Vec<u8> {
    let mut path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap_or(".".into()));
    path.push("./fixtures/self/");
    path.push(section);

    assert!(path.is_file());
    let mut file = File::open(path).unwrap();

    let mut buf = Vec::new();
    file.read_to_end(&mut buf).unwrap();
    buf
}

#[bench]
fn bench_parsing_debug_abbrev(b: &mut test::Bencher) {
    let debug_info = read_section("debug_info");
    let debug_info = DebugInfo::<LittleEndian>::new(&debug_info);
    let unit = debug_info.units()
        .next()
        .expect("Should have at least one compilation unit")
        .expect("And it should parse OK");

    let debug_abbrev = read_section("debug_abbrev");

    b.iter(|| {
        let debug_abbrev = DebugAbbrev::<LittleEndian>::new(&debug_abbrev);
        test::black_box(unit.abbreviations(debug_abbrev)
            .expect("Should parse abbreviations"));
    });
}

#[bench]
fn bench_parsing_debug_info(b: &mut test::Bencher) {
    let debug_abbrev = read_section("debug_abbrev");
    let debug_abbrev = DebugAbbrev::<LittleEndian>::new(&debug_abbrev);

    let debug_info = read_section("debug_info");

    b.iter(|| {
        let debug_info = DebugInfo::<LittleEndian>::new(&debug_info);

        let mut iter = debug_info.units();
        while let Some(unit) = iter.next().expect("Should parse compilation unit") {
            let abbrevs = unit.abbreviations(debug_abbrev)
                .expect("Should parse abbreviations");

            let mut cursor = unit.entries(&abbrevs);
            while let Some((_, entry)) = cursor.next_dfs().expect("Should parse next dfs") {
                let mut attrs = entry.attrs();
                while let Some(attr) = attrs.next().expect("Should parse entry's attribute") {
                    test::black_box(&attr);
                }
            }
        }
    });
}

#[bench]
fn bench_parsing_debug_info_tree(b: &mut test::Bencher) {
    let debug_abbrev = read_section("debug_abbrev");
    let debug_abbrev = DebugAbbrev::<LittleEndian>::new(&debug_abbrev);

    let debug_info = read_section("debug_info");

    b.iter(|| {
        let debug_info = DebugInfo::<LittleEndian>::new(&debug_info);

        let mut iter = debug_info.units();
        while let Some(unit) = iter.next().expect("Should parse compilation unit") {
            let abbrevs = unit.abbreviations(debug_abbrev)
                .expect("Should parse abbreviations");

            let mut tree = unit.entries_tree(&abbrevs, None).expect("Should have entries tree");
            parse_debug_info_tree(tree.iter());
        }
    });
}

fn parse_debug_info_tree(mut iter: EntriesTreeIter<LittleEndian>) {
    {
        let entry = iter.entry().expect("Should have current entry");
        let mut attrs = entry.attrs();
        while let Some(attr) = attrs.next().expect("Should parse entry's attribute") {
            test::black_box(&attr);
        }
    }
    while let Some(child) = iter.next().expect("Should parse child entry") {
        parse_debug_info_tree(child);
    }
}

#[bench]
fn bench_parsing_debug_aranges(b: &mut test::Bencher) {
    let debug_aranges = read_section("debug_aranges");
    let debug_aranges = DebugAranges::<LittleEndian>::new(&debug_aranges);

    b.iter(|| {
        let mut aranges = debug_aranges.items();
        while let Some(arange) = aranges.next().expect("Should parse arange OK") {
            test::black_box(arange);
        }
    });
}

#[bench]
fn bench_parsing_debug_pubnames(b: &mut test::Bencher) {
    let debug_pubnames = read_section("debug_pubnames");
    let debug_pubnames = DebugPubNames::<LittleEndian>::new(&debug_pubnames);

    b.iter(|| {
        let mut pubnames = debug_pubnames.items();
        while let Some(pubname) = pubnames.next().expect("Should parse pubname OK") {
            test::black_box(pubname);
        }
    });
}

#[bench]
fn bench_parsing_debug_types(b: &mut test::Bencher) {
    let debug_pubtypes = read_section("debug_pubtypes");
    let debug_pubtypes = DebugPubTypes::<LittleEndian>::new(&debug_pubtypes);

    b.iter(|| {
        let mut pubtypes = debug_pubtypes.items();
        while let Some(pubtype) = pubtypes.next().expect("Should parse pubtype OK") {
            test::black_box(pubtype);
        }
    });
}

// We happen to know that there is a line number program and header at
// offset 0 and that address size is 8 bytes. No need to parse DIEs to grab
// this info off of the compilation units.
const OFFSET: DebugLineOffset = DebugLineOffset(0);
const ADDRESS_SIZE: u8 = 8;

#[bench]
fn bench_parsing_line_number_program_opcodes(b: &mut test::Bencher) {
    let debug_line = read_section("debug_line");
    let debug_line = DebugLine::<LittleEndian>::new(&debug_line);

    b.iter(|| {
        let header = debug_line.header(OFFSET, ADDRESS_SIZE, None, None)
            .expect("Should parse line number program header");

        let mut opcodes = header.opcodes();
        while let Some(opcode) = opcodes.next_opcode(&header).expect("Should parse opcode") {
            test::black_box(opcode);
        }
    });
}

#[bench]
fn bench_executing_line_number_programs(b: &mut test::Bencher) {
    let debug_line = read_section("debug_line");
    let debug_line = DebugLine::<LittleEndian>::new(&debug_line);

    b.iter(|| {
        let header = debug_line.header(OFFSET, ADDRESS_SIZE, None, None)
            .expect("Should parse line number program header");

        let mut rows = header.rows();
        while let Some(row) = rows.next_row()
            .expect("Should parse and execute all rows in the line number program") {
            test::black_box(row);
        }
    });
}

// See comment above `test_parse_self_eh_frame`.
#[cfg(target_pointer_width="64")]
mod cfi {
    extern crate fallible_iterator;
    extern crate gimli;
    extern crate test;

    use super::*;
    use self::fallible_iterator::FallibleIterator;

    use gimli::{BaseAddresses, CieOrFde, EhFrame, FrameDescriptionEntry, LittleEndian,
                UninitializedUnwindContext, UnwindSection, UnwindTable};

    #[bench]
    fn iterate_entries_and_do_not_parse_any_fde(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);

        let bases = BaseAddresses::default()
            .set_cfi(0)
            .set_data(0)
            .set_text(0);

        b.iter(|| {
            let mut entries = eh_frame.entries(&bases);
            while let Some(entry) = entries.next().expect("Should parse CFI entry OK") {
                test::black_box(entry);
            }
        });
    }

    #[bench]
    fn iterate_entries_and_parse_every_fde(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);

        let bases = BaseAddresses::default()
            .set_cfi(0)
            .set_data(0)
            .set_text(0);

        b.iter(|| {
            let mut entries = eh_frame.entries(&bases);
            while let Some(entry) = entries.next().expect("Should parse CFI entry OK") {
                match entry {
                    CieOrFde::Cie(cie) => {
                        test::black_box(cie);
                    }
                    CieOrFde::Fde(partial) => {
                        let fde = partial.parse(|offset| eh_frame.cie_from_offset(&bases, offset))
                            .expect("Should be able to get CIE for FED");
                        test::black_box(fde);
                    }
                };
            }
        });
    }

    #[bench]
    fn iterate_entries_and_parse_every_fde_and_instructions(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);

        let bases = BaseAddresses::default()
            .set_cfi(0)
            .set_data(0)
            .set_text(0);

        b.iter(|| {
            let mut entries = eh_frame.entries(&bases);
            while let Some(entry) = entries.next().expect("Should parse CFI entry OK") {
                match entry {
                    CieOrFde::Cie(cie) => {
                        let mut instrs = cie.instructions();
                        while let Some(i) = instrs.next()
                            .expect("Can parse next CFI instruction OK") {
                            test::black_box(i);
                        }
                    }
                    CieOrFde::Fde(partial) => {
                        let fde = partial.parse(|offset| eh_frame.cie_from_offset(&bases, offset))
                            .expect("Should be able to get CIE for FED");
                        let mut instrs = fde.instructions();
                        while let Some(i) = instrs.next()
                            .expect("Can parse next CFI instruction OK") {
                            test::black_box(i);
                        }
                    }
                };
            }
        });
    }

    #[bench]
    fn iterate_entries_evaluate_every_fde(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);

        let bases = BaseAddresses::default()
            .set_cfi(0)
            .set_data(0)
            .set_text(0);

        let mut ctx = Some(UninitializedUnwindContext::new());

        b.iter(|| {
            let mut entries = eh_frame.entries(&bases);
            while let Some(entry) = entries.next().expect("Should parse CFI entry OK") {
                match entry {
                    CieOrFde::Cie(_) => {}
                    CieOrFde::Fde(partial) => {
                        let fde = partial.parse(|offset| eh_frame.cie_from_offset(&bases, offset))
                            .expect("Should be able to get CIE for FED");

                        let mut context = ctx.take()
                            .unwrap()
                            .initialize(fde.cie())
                            .expect("Should be able to initialize ctx");

                        {
                            let mut table = UnwindTable::new(&mut context, &fde);
                            while let Some(row) = table.next_row()
                                .expect("Should get next unwind table row") {
                                test::black_box(row);
                            }
                        }

                        ctx = Some(context.reset());
                    }
                };
            }
        });
    }

    fn instrs_len<'input>(fde: &FrameDescriptionEntry<'input,
                                                      LittleEndian,
                                                      EhFrame<'input, LittleEndian>>)
                          -> usize {
        fde.instructions().fold(0, |count, _| count + 1).expect("fold over instructions OK")
    }

    fn get_fde_with_longest_cfi_instructions<'input>
        (eh_frame: EhFrame<'input, LittleEndian>)
         -> FrameDescriptionEntry<'input, LittleEndian, EhFrame<'input, LittleEndian>> {
        let bases = BaseAddresses::default()
            .set_cfi(0)
            .set_data(0)
            .set_text(0);

        let mut longest: Option<(usize, FrameDescriptionEntry<_, _>)> = None;

        let mut entries = eh_frame.entries(&bases);
        while let Some(entry) = entries.next().expect("Should parse CFI entry OK") {
            match entry {
                CieOrFde::Cie(_) => {}
                CieOrFde::Fde(partial) => {
                    let fde = partial.parse(|offset| eh_frame.cie_from_offset(&bases, offset))
                        .expect("Should be able to get CIE for FED");

                    let this_len = instrs_len(&fde);

                    let found_new_longest = match longest {
                        None => true,
                        Some((longest_len, ref _fde)) => this_len > longest_len,
                    };

                    if found_new_longest {
                        longest = Some((this_len, fde));
                    }
                }
            };
        }

        longest.expect("At least one FDE in .eh_frame").1
    }

    #[bench]
    fn parse_longest_fde_instructions(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);
        let fde = get_fde_with_longest_cfi_instructions(eh_frame);

        b.iter(|| {
            let mut instrs = fde.instructions();
            while let Some(i) = instrs.next().expect("Should parse instruction OK") {
                test::black_box(i);
            }
        });
    }

    #[bench]
    fn eval_longest_fde_instructions_new_ctx_everytime(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);
        let fde = get_fde_with_longest_cfi_instructions(eh_frame);

        b.iter(|| {
            let mut ctx = UninitializedUnwindContext::new()
                .initialize(fde.cie())
                .expect("Should initialize the ctx OK");

            let mut table = UnwindTable::new(&mut ctx, &fde);
            while let Some(row) = table.next_row().expect("Should get next unwind table row") {
                test::black_box(row);
            }
        });
    }

    #[bench]
    fn eval_longest_fde_instructions_same_ctx(b: &mut test::Bencher) {
        let eh_frame = read_section("eh_frame");
        let eh_frame = EhFrame::<LittleEndian>::new(&eh_frame);
        let fde = get_fde_with_longest_cfi_instructions(eh_frame);

        let mut ctx = Some(UninitializedUnwindContext::new());

        b.iter(|| {
            let mut context = ctx.take()
                .unwrap()
                .initialize(fde.cie())
                .expect("Should be able to initialize ctx");

            {
                let mut table = UnwindTable::new(&mut context, &fde);
                while let Some(row) = table.next_row().expect("Should get next unwind table row") {
                    test::black_box(row);
                }
            }

            ctx = Some(context.reset());
        });
    }
}