Fuzz introspector
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues
Project coverage
Per-fuzzer coverage

Table of contents

Project overview: ninja
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: fuzzer
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/ninja/misc/manifest_fuzzer.cc
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: 2026-07-16

Project overview: ninja

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
13.0%
53 / 410
Cyclomatic complexity statically reachable by fuzzers
7.00%
222 / 3041
Runtime code coverage of functions
53.0%
219 / 410

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
fuzzer /src/ninja/misc/manifest_fuzzer.cc 118 409 8 17 374 265 manifest_fuzzer.cc

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: fuzzer

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 15 17.2%
gold [1:9] 0 0.0%
yellow [10:29] 0 0.0%
greenyellow [30:49] 0 0.0%
lawngreen 50+ 72 82.7%
All colors 87 100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked Calltree index Parent function Callsite Largest blocked function
2 5 LLVMFuzzerTestOneInput call site: 00005
2 70 Parser::Load(std::__1::basic_string , std::__1::allocator > const&, std::__1::basic_string , std::__1::allocator >*, Lexer*) call site: 00070
2 76 Parser::Load(std::__1::basic_string , std::__1::allocator > const&, std::__1::basic_string , std::__1::allocator >*, Lexer*) call site: 00076 __clang_call_terminate
2 81 LLVMFuzzerTestOneInput call site: 00081
2 84 LLVMFuzzerTestOneInput call site: 00084
1 13 emhash8::HashMap , std::__1::equal_to , std::__1::allocator >, emhash8::DefaultPolicy>::rehash(unsigned long) call site: 00013 abort
1 21 emhash8::HashMap , std::__1::equal_to , std::__1::allocator >, emhash8::DefaultPolicy>::rebuild(unsigned int, unsigned int, unsigned int) call site: 00021 __cxa_begin_catch
1 62 ManifestParser::ManifestParser(State*, FileReader*, ManifestParserOptions) call site: 00062
1 67 Parser::Load(std::__1::basic_string , std::__1::allocator > const&, std::__1::basic_string , std::__1::allocator >*, Lexer*) call site: 00067
1 79 LLVMFuzzerTestOneInput call site: 00079

Runtime coverage analysis

Covered functions
146
Functions that are reachable but not covered
27
Reachable functions
118
Percentage of reachable functions covered
77.12%
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
/src/ninja/misc/manifest_fuzzer.cc 1
/src/ninja/src/disk_interface.cc 1
/src/ninja/src/disk_interface.h 5
/src/ninja/src/state.cc 3
/src/ninja/src/third_party/emhash/hash_table8.hpp 21
/src/ninja/src/eval_env.h 6
/src/ninja/src/eval_env.cc 3
/src/ninja/src/string_piece.h 3
/src/ninja/src/state.h 2
/src/ninja/src/manifest_parser.h 2
/src/ninja/src/manifest_parser.cc 1
/src/ninja/src/parser.h 2
/src/ninja/src/lexer.h 1
/src/ninja/src/parser.cc 1
/src/ninja/src/metrics.cc 4
/src/ninja/src/metrics.h 1
/src/ninja/src/lexer.cc 1

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
ManifestParser::Parse(std::__1::basic_string ,std::__1::allocator >const&,std::__1::basic_string ,std::__1::allocator >const&,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/manifest_parser.cc 4 ['N/A', 'N/A', 'N/A', 'N/A'] 10 0 294 55 52 278 0 1176 996
DependencyScan::RecomputeNodeDirty(Node*,std::__1::vector >*,std::__1::vector >*,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/graph.cc 5 ['N/A', 'N/A', 'N/A', 'N/A', 'N/A'] 9 0 558 101 36 236 2 757 486
DyndepParser::Parse(std::__1::basic_string ,std::__1::allocator >const&,std::__1::basic_string ,std::__1::allocator >const&,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/dyndep_parser.cc 4 ['N/A', 'N/A', 'N/A', 'N/A'] 9 0 246 41 37 141 0 662 234
DepsLog::Recompact(std::__1::basic_string ,std::__1::allocator >const&,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/deps_log.cc 3 ['N/A', 'N/A', 'N/A'] 7 0 288 56 55 121 2 388 221
BuildLog::RecordCommand(Edge*,int,int,long) /src/ninja/src/build_log.cc 5 ['N/A', 'N/A', 'int', 'int', 'size_t'] 8 0 247 38 37 145 0 354 140
ParseMountInfo(std::__1::map ,std::__1::allocator >,CGroupSubSys,std::__1::less ,std::__1::allocator >>,std::__1::allocator ,std::__1::allocator >const,CGroupSubSys>>>&) /src/ninja/src/util.cc 2 ['N/A', 'N/A'] 3 0 376 77 63 29 2 138 114
BuildLog::OpenForWrite(std::__1::basic_string ,std::__1::allocator >const&,BuildLogUserconst&,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/build_log.cc 4 ['N/A', 'N/A', 'N/A', 'N/A'] 6 0 64 13 4 83 0 211 107
BuildLog::Restat(StringPiece,DiskInterfaceconst&,int,char**,std::__1::basic_string ,std::__1::allocator >*) /src/ninja/src/build_log.cc 7 ['N/A', 'N/A', 'size_t', 'N/A', 'int', 'N/A', 'N/A'] 4 0 381 68 64 65 0 173 64
DiskInterface::MakeDirs(std::__1::basic_string ,std::__1::allocator >const&) /src/ninja/src/disk_interface.cc 2 ['N/A', 'N/A'] 4 0 117 19 20 10 1 53 49
ParseSelfCGroup() /src/ninja/src/util.cc 1 ['N/A'] 3 0 186 39 36 20 2 72 42

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

Functions statically reachable by fuzzers
71.0%
290 / 410
Cyclomatic complexity statically reachable by fuzzers
83.0%
2520 / 3041

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/ninja/misc/manifest_fuzzer.cc

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=['LLVMFuzzerTestOneInput', 'Parser::Load(std::__1::basic_string, std::__1::allocator > const&, std::__1::basic_string, std::__1::allocator >*, Lexer*)', 'Parser::Load(std::__1::basic_string, std::__1::allocator > const&, std::__1::basic_string, std::__1::allocator >*, Lexer*)', 'emhash8::HashMap, std::__1::equal_to, std::__1::allocator >, emhash8::DefaultPolicy>::rehash(unsigned long)', 'emhash8::HashMap, std::__1::equal_to, std::__1::allocator >, emhash8::DefaultPolicy>::rebuild(unsigned int, unsigned int, unsigned int)', 'ManifestParser::ManifestParser(State*, FileReader*, ManifestParserOptions)', 'Parser::Load(std::__1::basic_string, std::__1::allocator > const&, std::__1::basic_string, std::__1::allocator >*, Lexer*)']

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

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
[] []
/src/ninja/src/graph.h [] []
/src/ninja/src/dyndep_parser.cc [] []
/src/ninja/src/depfile_parser.h [] []
/src/ninja/src/eval_env.h ['fuzzer'] ['fuzzer']
/src/ninja/src/jobserver.h [] []
/src/ninja/src/lexer.cc ['fuzzer'] ['fuzzer']
/src/ninja/misc/manifest_fuzzer.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/state.h ['fuzzer'] ['fuzzer']
/usr/local/bin/../include/c++/v1/stdexcept [] []
/src/ninja/src/graph.cc [] []
/src/ninja/src/dyndep_parser.h [] []
/src/ninja/src/string_piece_util.cc [] []
/usr/local/bin/../include/c++/v1/istream [] []
/src/ninja/src/build_log.h [] []
/src/ninja/src/disk_interface.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/metrics.h ['fuzzer'] ['fuzzer']
/src/ninja/src/manifest_parser.cc ['fuzzer'] ['fuzzer']
/usr/local/bin/../include/c++/v1/string [] []
/src/ninja/src/state.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/util.cc [] []
/src/ninja/src/parser.h ['fuzzer'] ['fuzzer']
/src/ninja/src/disk_interface.h ['fuzzer'] ['fuzzer']
/usr/local/bin/../include/c++/v1/__charconv/from_chars_integral.h [] []
/src/ninja/src/explanations.cc [] []
/src/ninja/src/eval_env.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/parser.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/lexer.h ['fuzzer'] ['fuzzer']
/src/ninja/src/deps_log.cc [] []
/src/ninja/src/metrics.cc ['fuzzer'] ['fuzzer']
/src/ninja/src/manifest_parser.h ['fuzzer'] []
/src/ninja/src/depfile_parser.cc [] []
/src/ninja/src/third_party/rapidhash/rapidhash.h [] []
/src/ninja/src/version.cc [] []
/src/ninja/src/third_party/emhash/hash_table8.hpp ['fuzzer'] ['fuzzer']
/src/ninja/src/string_piece.h ['fuzzer'] ['fuzzer']
/src/ninja/src/dyndep.h [] []
/src/ninja/src/build_log.cc [] []
/src/ninja/src/dyndep.cc [] []
/src/ninja/src/edit_distance.cc [] []
/src/ninja/src/string_piece_util.h [] []
/src/ninja/src/deps_log.h [] []

Directories in report

Directory
/usr/local/bin/../include/c++/v1/
/usr/local/bin/../include/c++/v1/__charconv/
/src/ninja/src/
/src/ninja/misc/
/src/ninja/src/third_party/rapidhash/
/src/ninja/src/third_party/emhash/

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
fuzzer fuzzerLogFile-0-djqERA7UEZ.data fuzzerLogFile-0-djqERA7UEZ.data.yaml fuzzer.covreport