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

Table of contents

Project overview: sqlite3
High level conclusions
Reachability and coverage overview
Fuzzers overview
Project functions overview
Fuzzer details
Fuzzer: ossfuzz
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
test/ossfuzz.c
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: 2026-07-15

Project overview: sqlite3

High level conclusions

Reachability and coverage overview

Functions statically reachable by fuzzers
69.0%
1923 / 2770
Cyclomatic complexity statically reachable by fuzzers
76.0%
19653 / 25820
Runtime code coverage of functions
79.0%
2193 / 2770

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
ossfuzz test/ossfuzz.c 1940 918 85 2 66531 19694 ossfuzz.c

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: ossfuzz

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 11731 73.1%
gold [1:9] 110 0.68%
yellow [10:29] 34 0.21%
greenyellow [30:49] 18 0.11%
lawngreen 50+ 4142 25.8%
All colors 16035 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
1368 12775 sqlite3DbSpanDup call site: 12775 sqlite3AddPrimaryKey
680 15228 sqlite3_hard_heap_limit64 call site: 15228 sqlite3Pragma
619 6205 sqlite3_value_int call site: 06205 sqlite3ExprCode
516 5536 sqlite3VdbeChangeToNoop call site: 05536 sqlite3ConstructBloomFilter
470 6827 sqlite3VdbeJumpHereOrPopInst call site: 06827 sqlite3WhereEnd
400 5133 sqlite3LogEstFromDouble call site: 05133 constructAutomaticIndex
352 4403 sqlite3_str_new call site: 04403 exprAnalyze
305 14146 sqlite3VdbeTakeOpArray call site: 14146 sqlite3CodeDropTable
291 4110 sqlite3VdbeChangeOpcode call site: 04110 sqlite3WhereBegin
282 12262 sqlite3Step call site: 12262 sqlite3InitOne
259 4873 sqlite3VdbeChangeP3 call site: 04873 exprAnalyze
219 3281 sqlite3Dequote call site: 03281 flattenSubquery

Runtime coverage analysis

Covered functions
2195
Functions that are reachable but not covered
208
Reachable functions
1940
Percentage of reachable functions covered
89.28%
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
test/ossfuzz.c 5
bld/sqlite3.c 1919

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
jsonExtractFunc /src/sqlite3/bld/sqlite3.c 3 ['N/A', 'int', 'N/A'] 42 0 378 70 24 262 0 2175 839
resolveExprStep /src/sqlite3/bld/sqlite3.c 2 ['N/A', 'N/A'] 46 0 2719 473 129 318 1 2692 510
strftimeFunc /src/sqlite3/bld/sqlite3.c 3 ['N/A', 'int', 'N/A'] 39 0 599 93 17 201 0 1517 259
selectExpander /src/sqlite3/bld/sqlite3.c 2 ['N/A', 'N/A'] 69 0 2420 404 116 1920 0 19665 236
unixOpen /src/sqlite3/bld/sqlite3.c 5 ['N/A', 'N/A', 'N/A', 'int', 'N/A'] 38 0 1145 242 67 188 0 1404 178
renameColumnFunc /src/sqlite3/bld/sqlite3.c 3 ['N/A', 'int', 'N/A'] 69 0 779 118 39 1929 0 19577 162
sqlite3_test_control /src/sqlite3/bld/sqlite3.c 1 ['int'] 44 0 1626 225 59 279 0 1935 153

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

Functions statically reachable by fuzzers
76.0%
2115 / 2770
Cyclomatic complexity statically reachable by fuzzers
85.0%
21851 / 25820

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.

test/ossfuzz.c

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=['sqlite3DbSpanDup', 'sqlite3_hard_heap_limit64', 'sqlite3_value_int', 'sqlite3VdbeChangeToNoop', 'sqlite3VdbeJumpHereOrPopInst', 'sqlite3LogEstFromDouble', 'sqlite3_str_new', 'sqlite3VdbeTakeOpArray', 'sqlite3VdbeChangeOpcode', 'sqlite3Step']

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
sqlite3_vtab_config 39 21 53.84% ['ossfuzz']
sqlite3_config 160 16 10.0% ['ossfuzz']
unixWrite 37 14 37.83% ['ossfuzz']
unixFileControl 144 32 22.22% ['ossfuzz']
fcntlSizeHint 38 14 36.84% ['ossfuzz']
sqlite3PagerSharedLock 106 17 16.03% ['ossfuzz']
pager_incr_changecounter 41 13 31.70% ['ossfuzz']
writeSuperJournal 41 13 31.70% ['ossfuzz']
syncJournal 64 15 23.43% ['ossfuzz']
sqlite3WalClose 39 5 12.82% ['ossfuzz']
vdbeCommit 166 55 33.13% ['ossfuzz']
sqlite3VtabSavepoint 36 7 19.44% ['ossfuzz']
hasSharedCacheTableLock 39 8 20.51% ['ossfuzz']
sqlite3BtreeOpen 220 105 47.72% ['ossfuzz']
sqlite3PagerSetFlags 36 19 52.77% ['ossfuzz']
sqlite3VtabBegin 32 7 21.87% ['ossfuzz']
exprCodeInlineFunction 78 38 48.71% ['ossfuzz']
sqlite3VtabOverloadFunction 45 19 42.22% ['ossfuzz']
existsToJoin 45 21 46.66% ['ossfuzz']
countOfViewOptimization 67 24 35.82% ['ossfuzz']
sqlite3WindowCodeInit 61 32 52.45% ['ossfuzz']
sqlite3ParseUri 167 30 17.96% ['ossfuzz']
sqlite3AutoLoadExtensions 33 9 27.27% ['ossfuzz']
createCollation 44 20 45.45% ['ossfuzz']

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/sqlite3/bld/sqlite3.c ['ossfuzz'] ['ossfuzz']
/src/sqlite3/test/ossfuzz.c ['ossfuzz'] ['ossfuzz']

Directories in report

Directory
/src/sqlite3/test/
/src/sqlite3/bld/

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
ossfuzz fuzzerLogFile-0-3Dl7OjNnoU.data fuzzerLogFile-0-3Dl7OjNnoU.data.yaml ossfuzz.covreport