High level conclusions

Fuzzer parser is blocked:

The runtime code coverage of parser covers 28.57% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Fuzzer toml is blocked:

The runtime code coverage of toml covers 28.57% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Fuzzer json is blocked:

The runtime code coverage of json covers 28.57% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Fuzzers reach 0.146% of cyclomatic complexity.

Fuzzers reach 0.123% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

1 / 808

Cyclomatic complexity statically reachable by fuzzers

1 / 684

Runtime code coverage of functions

167 / 808

Warning: The number of runtime covered functions are larger than the number of reachable functions. This means that Fuzz Introspector found there are more functions covered at runtime than what is considered reachable based on the static analysis. This is a limitation in the analysis as anything covered at runtime is by definition reachable by the fuzzers.
This is likely due to a limitation in the static analysis. In this case, the count of functions covered at runtime is the true value, which means this is what should be considered "achieved" by the fuzzer.

Use the project functions table below to query all functions that were not covered at runtime.

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

For further technical details on the meaning of columns in the below table, please see the Glossary .

Func name	Functions filename	Args	Function call depth	Reached by Fuzzers	Runtime reached by Fuzzers	Combined reached by Fuzzers	Fuzzers runtime hit	Func lines hit %	I Count	BB Count	Cyclomatic complexity	Functions reached	Reached by functions	Accumulated cyclomatic complexity	Undiscovered complexity

Fuzzer: json

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	378	91.9%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	33	8.02%
All colors	411	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
167	6	pest::set_call_limit	call site: 00006	J::s::o::n::P::a::r::s::e::r::::::::p::a::r::s::e::value
68	321	ParserState::inc_call_check_limit	call site: 00321	bool
41	248	ExprTopDownIterator::next	call site: 00248	ExprTopDownIterator::next
37	180	ParserState::match_string	call site: 00180	Stack::clear_snapshot
19	391	pest::set_call_limit	call site: 00391	object
14	302	ParserState::match_range	call site: 00302	number
12	223	ParserState::match_string	call site: 00223	ExprTopDownIterator::next
8	238	ExprTopDownIterator::next	call site: 00238
3	174	ParserState::match_string	call site: 00174	fails_with
2	0	EP	call site: 00000
2	3	pest::set_call_limit	call site: 00003
2	219	ParserState::match_string	call site: 00219	ParserState::handle_token_parse_result

Runtime coverage analysis

Covered functions

309

Functions that are reachable but not covered

5

Reachable functions

7

Percentage of reachable functions covered

28.57%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
grammars/fuzz/fuzz_targets/json.rs	7
pest/src/parser_state.rs	29
meta/src/validator.rs	4
grammars/benches/json.rs	10
meta/src/parser.rs	51
meta/src/optimizer/restorer.rs	7
meta/src/ast.rs	9
pest/src/iterators/flat_pairs.rs	1
meta/fuzz/fuzz_targets/parser.rs	3
pest/src/iterators/pair.rs	3
pest/src/iterators/pairs.rs	1
pest/tests/json.rs	13
pest/src/macros.rs	8
pest/src/stack.rs	7
pest/src/span.rs	8

Fuzzer: http

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	71	100.%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	0	0.0%
All colors	71	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
70	0	EP	call site: 00000	PestParser::parse

Runtime coverage analysis

Covered functions

318

Functions that are reachable but not covered

2

Reachable functions

3

Percentage of reachable functions covered

33.33%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
grammars/fuzz/fuzz_targets/http.rs	3
meta/src/parser.rs	1

Fuzzer: toml

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	431	92.8%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	33	7.11%
All colors	464	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
167	6	pest::set_call_limit	call site: 00006	J::s::o::n::P::a::r::s::e::r::::::::p::a::r::s::e::value
72	391	pest::set_call_limit	call site: 00391	PestParser::parse
68	321	ParserState::inc_call_check_limit	call site: 00321	bool
66	223	ParserState::match_string	call site: 00223	ExprTopDownIterator::next
18	199	Stack::snapshot	call site: 00199	Stack::clear_snapshot
15	180	ParserState::match_string	call site: 00180	tests::wrong_pos
14	302	ParserState::match_range	call site: 00302	number
3	174	ParserState::match_string	call site: 00174	fails_with
2	0	EP	call site: 00000
2	219	ParserState::match_string	call site: 00219	ParserState::handle_token_parse_result
1	197	Stack::snapshot	call site: 00197
1	291	ParserState::match_range	call site: 00291	fails_with

Runtime coverage analysis

Covered functions

701

Functions that are reachable but not covered

5

Reachable functions

7

Percentage of reachable functions covered

28.57%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
grammars/fuzz/fuzz_targets/toml.rs	7
pest/src/parser_state.rs	29
meta/src/validator.rs	4
grammars/benches/json.rs	10
meta/src/parser.rs	52
meta/src/optimizer/restorer.rs	7
meta/src/ast.rs	9
pest/src/iterators/flat_pairs.rs	1
meta/fuzz/fuzz_targets/parser.rs	3
pest/src/iterators/pair.rs	3
pest/src/iterators/pairs.rs	1
pest/tests/json.rs	13
pest/src/macros.rs	8
pest/src/stack.rs	7
pest/src/span.rs	8

Fuzzer: parser

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	434	91.7%
gold	[1:9]	0	0.0%
yellow	[10:29]	0	0.0%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	39	8.24%
All colors	473	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
175	35	pest_meta::parser::parse	call site: 00035	J::s::o::n::P::a::r::s::e::r::::::::p::a::r::s::e::value
108	358	ParserState::inc_call_check_limit	call site: 00358	bool
41	285	ExprTopDownIterator::next	call site: 00285	ExprTopDownIterator::next
28	6	pest::set_call_limit	call site: 00006	ExprTopDownIterator::iterate_expr
18	236	Stack::snapshot	call site: 00236	Stack::clear_snapshot
15	217	ParserState::match_string	call site: 00217	tests::wrong_pos
14	339	ParserState::match_range	call site: 00339	number
12	260	ParserState::match_string	call site: 00260	ExprTopDownIterator::next
8	275	ExprTopDownIterator::next	call site: 00275
4	468	pest::set_call_limit	call site: 00468
3	211	ParserState::match_string	call site: 00211	fails_with
2	0	EP	call site: 00000

Runtime coverage analysis

Covered functions

683

Functions that are reachable but not covered

5

Reachable functions

7

Percentage of reachable functions covered

28.57%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Warning: The number of covered functions are larger than the number of reachable functions. This means that there are more functions covered at runtime than are extracted using static analysis. This is likely a result of the static analysis component failing to extract the right call graph or the coverage runtime being compiled with sanitizers in code that the static analysis has not analysed. This can happen if lto/gold is not used in all places that coverage instrumentation is used.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
meta/fuzz/fuzz_targets/parser.rs	7
pest/src/parser_state.rs	29
meta/src/validator.rs	4
grammars/benches/json.rs	10
meta/src/parser.rs	52
meta/src/optimizer/restorer.rs	7
meta/src/ast.rs	9
pest/src/iterators/flat_pairs.rs	1
pest/tests/json.rs	13
pest/src/macros.rs	8
pest/src/stack.rs	7
pest/src/span.rs	8
pest/src/iterators/pair.rs	3
pest/src/iterators/pairs.rs	1

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Func name	Functions filename	Arg count	Args	Function depth	hitcount	instr count	bb count	cyclomatic complexity	Reachable functions	Incoming references	total cyclomatic complexity	Unreached complexity

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

Functions statically reachable by fuzzers

1 / 808

Cyclomatic complexity statically reachable by fuzzers

1 / 684

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

Func name	Functions filename	Args	Function call depth	Reached by Fuzzers	Runtime reached by Fuzzers	Combined reached by Fuzzers	Fuzzers runtime hit	Func lines hit %	I Count	BB Count	Cyclomatic complexity	Functions reached	Reached by functions	Accumulated cyclomatic complexity	Undiscovered complexity

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

grammars/fuzz/fuzz_targets/json.rs

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['pest::set_call_limit', 'ParserState::inc_call_check_limit', 'ExprTopDownIterator::next', 'ParserState::match_string', 'ParserState::match_range']

grammars/fuzz/fuzz_targets/http.rs

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

grammars/fuzz/fuzz_targets/toml.rs

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['pest::set_call_limit', 'ParserState::inc_call_check_limit', 'ParserState::match_string', 'Stack::snapshot', 'ParserState::match_range']

meta/fuzz/fuzz_targets/parser.rs

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['pest_meta::parser::parse', 'ParserState::inc_call_check_limit', 'ExprTopDownIterator::next', 'pest::set_call_limit', 'Stack::snapshot', 'ParserState::match_string', 'ParserState::match_range']

This section shows analysis of runtime coverage data.

For futher technical details on how this section is generated, please see the Glossary .

Complex functions with low coverage

Func name	Function total lines	Lines covered at runtime	percentage covered	Reached by fuzzers
memchr::memmem::searcher::Searcher::new::memchr::arch::all::packedpair::DefaultFrequencyRank	48	23	47.91%

New fuzzers

The below fuzzers are templates and suggestions for how to target the set of optimal functions above

This section shows which files and directories are considered in this report. The main reason for showing this is fuzz introspector may include more code in the reasoning than is desired. This section helps identify if too many files/directories are included, e.g. third party code, which may be irrelevant for the threat model. In the event too much is included, fuzz introspector supports a configuration file that can exclude data from the report. See the following link for more information on how to create a config file: link

Files in report

Source file	Reached by	Covered by
/src/pest/meta/src/optimizer/concatenator.rs	[]	[]
/src/pest/debugger/src/lib.rs	[]	[]
/src/pest/meta/src/optimizer/unroller.rs	[]	[]
/src/pest/meta/src/optimizer/factorizer.rs	[]	[]
/src/pest/meta/src/validator.rs	['json', 'toml', 'parser']	[]
/src/pest/meta/fuzz/fuzz_targets/parser.rs	['json', 'toml', 'parser']	[]
/src/pest/pest/src/iterators/line_index.rs	[]	[]
/src/pest/pest/src/iterators/tokens.rs	[]	[]
/src/pest/generator/src/generator.rs	[]	[]
/src/pest/meta/src/grammar.rs	[]	[]
/src/pest/vm/src/macros.rs	[]	[]
/src/pest/pest/benches/stack.rs	[]	[]
/src/pest/vm/tests/grammar.rs	[]	[]
/src/pest/vm/src/lib.rs	[]	[]
/src/pest/pest/src/iterators/pairs.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/derive/tests/grammar.rs	[]	[]
/src/pest/generator/src/docs.rs	[]	[]
/src/pest/meta/src/optimizer/rotater.rs	[]	[]
/src/pest/grammars/tests/json.rs	[]	[]
/src/pest/grammars/tests/toml.rs	[]	[]
/src/pest/grammars/src/lib.rs	[]	[]
/src/pest/meta/src/optimizer/skipper.rs	[]	[]
/src/pest/pest/src/macros.rs	['json', 'toml', 'parser']	[]
/src/pest/pest/src/pratt_parser.rs	[]	[]
/src/pest/derive/tests/lists.rs	[]	[]
/src/pest/pest/src/error.rs	[]	[]
/src/pest/grammars/benches/http.rs	[]	[]
/src/pest/vm/tests/lists.rs	[]	[]
/src/pest/derive/tests/reporting.rs	[]	[]
/src/pest/meta/build.rs	[]	[]
/src/pest/derive/tests/grammar_inline.rs	[]	[]
/src/pest/generator/src/parse_derive.rs	[]	[]
/src/pest/generator/src/macros.rs	[]	[]
/src/pest/pest/src/stack.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/pest/src/position.rs	[]	[]
/src/pest/pest/src/span.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/pest/examples/parens.rs	[]	[]
/src/pest/meta/src/lib.rs	[]	[]
/src/pest/pest/src/unicode/mod.rs	[]	[]
/src/pest/grammars/tests/http.rs	[]	[]
/src/pest/grammars/fuzz/fuzz_targets/toml.rs	['toml']	[]
/src/pest/meta/src/ast.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/derive/examples/calc.rs	[]	[]
/src/pest/derive/tests/surround.rs	[]	[]
/src/pest/pest/tests/json.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/vm/tests/surround.rs	[]	[]
/src/pest/derive/tests/oneormore.rs	[]	[]
/src/pest/grammars/tests/sql.rs	[]	[]
/src/pest/pest/src/prec_climber.rs	[]	[]
/src/pest/meta/src/optimizer/restorer.rs	['json', 'toml', 'parser']	[]
/src/pest/pest/src/parser_state.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/generator/src/lib.rs	[]	[]
/src/pest/debugger/src/main.rs	[]	[]
/src/pest/bootstrap/src/main.rs	[]	[]
/src/pest/derive/tests/implicit.rs	[]	[]
/src/pest/grammars/benches/json.rs	['json', 'toml', 'parser']	[]
/src/pest/meta/src/optimizer/mod.rs	[]	[]
/src/pest/grammars/fuzz/fuzz_targets/json.rs	['json']	[]
/src/pest/pest/src/iterators/flat_pairs.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/meta/src/parser.rs	['json', 'http', 'toml', 'parser']	['json', 'http', 'toml', 'parser']
/src/pest/pest/tests/calculator.rs	[]	[]
/src/pest/grammars/fuzz/fuzz_targets/http.rs	['http']	[]
/src/pest/meta/src/optimizer/lister.rs	[]	[]
/src/pest/pest/src/iterators/pair.rs	['json', 'toml', 'parser']	['json', 'toml', 'parser']
/src/pest/derive/tests/opt.rs	[]	[]

Directories in report

Directory
/src/pest/meta/src/optimizer/
/src/pest/vm/src/
/src/pest/pest/src/
/src/pest/meta/
/src/pest/meta/src/
/src/pest/derive/tests/
/src/pest/bootstrap/src/
/src/pest/grammars/tests/
/src/pest/vm/tests/
/src/pest/generator/src/
/src/pest/pest/examples/
/src/pest/pest/benches/
/src/pest/meta/fuzz/fuzz_targets/
/src/pest/grammars/fuzz/fuzz_targets/
/src/pest/grammars/src/
/src/pest/pest/src/iterators/
/src/pest/pest/tests/
/src/pest/debugger/src/
/src/pest/grammars/benches/
/src/pest/pest/src/unicode/
/src/pest/derive/examples/

This section shows a list of 3rd party function calls and their relative coverage information. By static analysis of the target project code, all of the 3rd party function call and their caller information, including the source file and line number that initiate the call are captured. The caller source code file and line number are shown in column 2 while column 1 is the function name of the 3rd party function call. Each occurrent of the 3rd party function call will occuply a separate row. Column 3 of each row indicate if the 3rd party call in the source file line is unreachable. Column 4 lists all fuzzers that have covered that particular system call in that specific location (source file and line)during their dynamic fuzzing.

Function in each files in report

Target sink	Callsite location	Reached by fuzzer	Covered by Fuzzers