Fuzz introspector
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Project coverage

Table of contents

Project overview: pyparsing
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzz_parse
Call tree
Fuzz blockers
Runtime coverage analysis
Files reached
Analyses and suggestions
Optimal target analysis
Remaining optimal interesting functions
All functions overview
Fuzz engine guidance
/src/fuzz_parse.py
Dictionary
Fuzzer function priority
Runtime coverage analysis
Complex functions with low coverage
Files and Directories in report
Files in report
Directories in report
Metadata section
Report generation date: 2025-07-12

Project overview: pyparsing

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
25.0%
115 / 458
Cyclomatic complexity statically reachable by fuzzers
28.0%
448 / 1623
Runtime code coverage of functions
45.0%
208 / 458

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.

Fuzzers overview

Fuzzer Fuzzer filename Functions Reached Functions unreached Fuzzer depth Files reached Basic blocks reached Cyclomatic complexity Details
fuzz_parse /src/fuzz_parse.py 324 602 10 8 287 1072 fuzz_parse.py

Project functions overview

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 details

Fuzzer: fuzz_parse

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

Full calltree

Call tree overview bitmap:

The distribution of callsites in terms of coloring is
Color Runtime hitcount Callsite count Percentage
red 0 951 73.0%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 351 26.9%
All colors 1302 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
105 869 pyparsing.util.replaced_by_pep8._inner call site: 00869 pyparsing.util.replaced_by_pep8._inner
73 473 pyparsing.core.Word.parseImpl call site: 00473 pyparsing.core.SkipTo.parseImpl
61 1130 pyparsing.core.CharsNotIn.__init__ call site: 01130 pyparsing.util.replaced_by_pep8._inner
56 329 pyparsing.core.ParserElement._parseNoCache call site: 00329 pyparsing.core.NotAny.parseImpl
52 1020 pyparsing.util.replaced_by_pep8._inner call site: 01020 pyparsing.util.replaced_by_pep8._inner
51 1201 pyparsing.util.replaced_by_pep8._inner call site: 01201 pyparsing.helpers.counted_array
50 663 pyparsing.core.ParserElement._parseNoCache call site: 00663 pyparsing.util.replaced_by_pep8._inner
39 387 pyparsing.core.StringEnd.__init__ call site: 00387 pyparsing.util.replaced_by_pep8._inner
34 726 pyparsing.util.replaced_by_pep8._inner call site: 00726 pyparsing.core.ParserElement.split
28 548 pyparsing.core.Word.parseImpl_regex call site: 00548 pyparsing.core.NotAny.parseImpl
27 1078 pyparsing.core.FollowedBy.__init__ call site: 01078 pyparsing.util.replaced_by_pep8._inner
26 828 pyparsing.core.ParserElement.parse_string call site: 00828 pyparsing.core.ParserElement.set_break.breaker

Runtime coverage analysis

Covered functions
225
Functions that are reachable but not covered
252
Reachable functions
324
Percentage of reachable functions covered
22.22%
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.
Function name source code lines source lines hit percentage hit

Files reached

filename functions hit
/ 1
...fuzz_parse 18
pyparsing.core 231
pyparsing.util 69
pyparsing.helpers 59
pyparsing.actions 3
pyparsing.results 3
pyparsing.testing 23

Analyses and suggestions

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
pyparsing.diagram.to_railroad pyparsing.diagram 6 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 57 0 5 5 5 338 1 1142 90
pyparsing.results.ParseResults.dump pyparsing.results 5 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 4 0 9 7 6 19 1 66 42
pyparsing.testing.pyparsing_test.reset_pyparsing_context.restore pyparsing.testing 1 ['N/A'] 4 0 4 2 4 16 1 54 39

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

Functions statically reachable by fuzzers
31.0%
142 / 458
Cyclomatic complexity statically reachable by fuzzers
34.0%
559 / 1623

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

Fuzz engine guidance

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.

/src/fuzz_parse.py

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=['pyparsing.util.replaced_by_pep8._inner', 'pyparsing.core.Word.parseImpl', 'pyparsing.core.CharsNotIn.__init__', 'pyparsing.core.ParserElement._parseNoCache', 'pyparsing.core.StringEnd.__init__', 'pyparsing.core.Word.parseImpl_regex']

Runtime coverage analysis

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
pyparsing.core.ParserElement._parseNoCache 61 24 39.34% ['fuzz_parse']
pyparsing.core.ParserElement._parseCache 36 1 2.777% ['fuzz_parse']
pyparsing.core.ParserElement.scan_string 41 0 0.0% ['fuzz_parse']
pyparsing.core.ParserElement.run_tests 76 0 0.0% ['fuzz_parse']
pyparsing.core.QuotedString.__init__ 52 0 0.0% []
pyparsing.core.Or.parseImpl 61 0 0.0% ['fuzz_parse']
pyparsing.core.Each.parseImpl 55 0 0.0% ['fuzz_parse']
pyparsing.core.SkipTo.parseImpl 35 2 5.714% ['fuzz_parse']
pyparsing.core.Forward.parseImpl 45 0 0.0% []
pyparsing.util.make_compressed_re.get_suffixes_from_common_prefixes 44 0 0.0% []
pyparsing.helpers.one_of 48 0 0.0% ['fuzz_parse']
pyparsing.helpers.infix_notation._FB.parseImpl 69 0 0.0% ['fuzz_parse']
pyparsing.helpers.indentedBlock.checkUnindent 32 14 43.75% ['fuzz_parse']
pyparsing.exceptions.ParseBaseException.explain_exception 35 0 0.0% []
pyparsing.testing.pyparsing_test.with_line_numbers 41 0 0.0% ['fuzz_parse']

Files and Directories in report

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
[] []
[] []
pyparsing.util ['fuzz_parse'] []
pyparsing.common [] []
pyparsing.unicode [] []
abc [] []
sys [] []
contextlib [] []
difflib [] []
operator [] []
pyparsing.exceptions [] []
pyparsing.actions ['fuzz_parse'] []
re [] []
pathlib [] []
threading [] []
io [] []
warnings [] []
inspect [] []
datetime [] []
pyparsing [] []
pyparsing.core ['fuzz_parse'] []
pyparsing.tools.cvt_pyparsing_pep8_names [] []
argparse [] []
pyparsing.tools [] []
itertools [] []
pyparsing.diagram [] []
pyparsing.helpers ['fuzz_parse'] []
...fuzz_parse ['fuzz_parse'] []
atheris [] []
os [] []
pyparsing.results ['fuzz_parse'] []
functools [] []
collections [] []
typing [] []
traceback [] []
types [] []
railroad [] []
pyparsing.testing ['fuzz_parse'] []
jinja2 [] []

Directories in report

Directory

Metadata section

This sections shows the raw data that is used to produce this report. This is mainly used for further processing and developer debugging.

Fuzzer Calltree file Program data file Coverage file
fuzz_parse fuzzerLogFile-fuzz_parse.data fuzzerLogFile-fuzz_parse.data.yaml all_cov.json