High level conclusions

Fuzzers reach 51.01% code coverage.

Fuzzers reach 49.48% of cyclomatic complexity.

Fuzzers reach 54.51% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

997 / 1829

Cyclomatic complexity statically reachable by fuzzers

7600 / 15357

Runtime code coverage of functions

933 / 1829

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: fuzz_regexp

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	213	35.6%
gold	[1:9]	6	1.00%
yellow	[10:29]	3	0.50%
greenyellow	[30:49]	4	0.67%
lawngreen	50+	371	62.1%
All colors	597	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
47	225	unicode_case1	call site: 00225	unicode_prop_ops
35	185	cr_op	call site: 00185	unicode_prop
18	158	re_string_list_free	call site: 00158	parse_unicode_property
14	322	lre_canonicalize	call site: 00322	parse_class_string_disjunction
14	371	re_parse_nested_class	call site: 00371	re_parse_class_set_operand
13	275	cr_op1	call site: 00275	re_string_list_canonicalize
10	408	re_emit_char	call site: 00408	re_emit_range
8	298	cr_regexp_canonicalize	call site: 00298	lre_case_conv_entry
8	343	get_class_atom	call site: 00343	re_string_list_canonicalize
7	400	re_emit_range	call site: 00400	rqsort
6	177	cr_add_interval	call site: 00177	cr_op
4	364	re_string_list_op	call site: 00364	re_string_find2

Runtime coverage analysis

Covered functions

105

Functions that are reachable but not covered

32

Reachable functions

135

Percentage of reachable functions covered

76.3%

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
fuzz/fuzz_regexp.c	4
libregexp.c	56
cutils.c	15
./cutils.h	14
./libunicode.h	7
libunicode.c	31

Fuzzer: fuzz_eval

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	3657	70.4%
gold	[1:9]	770	14.8%
yellow	[10:29]	267	5.14%
greenyellow	[30:49]	50	0.96%
lawngreen	50+	446	8.59%
All colors	5190	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
288	3904	lre_js_is_ident_next	call site: 03904	re_parse_disjunction
188	2792	JS_CallInternal	call site: 02792	js_binary_logic_slow
182	4825	js_std_add_helpers	call site: 04825	js_print
136	2262	JS_ConcatString3	call site: 02262	JS_DefinePropertyValue
104	3651	JS_AddIntrinsicDate	call site: 03651	js_Date_parse
81	2601	js_binary_arith_slow	call site: 02601	js_bigint_add
75	4685	string_buffer_putc_slow	call site: 04685	json_parse_value
64	717	round_to_d	call site: 00717	js_new_string8_len
56	3050	js_async_function_resume	call site: 03050	js_promise_resolve
53	2198	JS_CallInternal	call site: 02198	JS_NewSymbolFromAtom
53	4226	re_parse_term	call site: 04226	re_emit_goto
51	5111	js_std_await	call site: 05111	js_os_poll

Runtime coverage analysis

Covered functions

659

Functions that are reachable but not covered

480

Reachable functions

962

Percentage of reachable functions covered

50.1%

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
fuzz/fuzz_eval.c	1
quickjs.c	700
./list.h	6
./cutils.h	28
./quickjs.h	22
dtoa.c	37
cutils.c	19
./libunicode.h	9
libunicode.c	32
libregexp.c	49
fuzz/fuzz_common.c	3
quickjs-libc.c	32

Fuzzer: fuzz_compile

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	3155	55.9%
gold	[1:9]	43	0.76%
yellow	[10:29]	51	0.90%
greenyellow	[30:49]	177	3.13%
lawngreen	50+	2215	39.2%
All colors	5641	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
182	4825	js_std_add_helpers	call site: 04825	js_print
173	3962	re_string_list_free	call site: 03962	parse_class_string_disjunction
77	3107	js_async_function_call	call site: 03107	JS_NewCFunctionData
74	4442	JS_AddIntrinsicTypedArrays	call site: 04442	js_typed_array_constructor_obj
70	3653	js_date_constructor	call site: 03653	js_Date_parse
69	2106	js_for_of_start	call site: 02106	JS_GetPropertyInternal
65	4695	ident_realloc	call site: 04695	json_parse_value
56	3050	js_async_function_resume	call site: 03050	js_promise_resolve
51	4228	re_parse_term	call site: 04228	re_emit_goto
46	4141	get_class_atom	call site: 04141	re_parse_class_set_operand
45	2486	JS_ConcatString2	call site: 02486	js_new_string_rope
45	4339	JS_AddIntrinsicMapSet	call site: 04339	js_create_from_ctor

Runtime coverage analysis

Covered functions

882

Functions that are reachable but not covered

376

Reachable functions

1025

Percentage of reachable functions covered

63.32%

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
fuzz/fuzz_compile.c	1
quickjs.c	762
./list.h	6
./cutils.h	29
./quickjs.h	22
dtoa.c	37
cutils.c	19
./libunicode.h	9
libunicode.c	32
libregexp.c	49
fuzz/fuzz_common.c	3
quickjs-libc.c	32

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
__JS_EvalInternal	/src/quickjs/quickjs.c	8	['N/A', 'size_t', 'size_t', 'N/A', 'size_t', 'N/A', 'int', 'int']	95	0	341	58	20	818	0	7392	2685
js_json_stringify	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	75	0	20	3	2	645	0	4892	306
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	68	0	777	127	51	648	0	5104	207
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	68	0	155	31	13	634	0	4726	126
js_os_exec	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	70	0	743	161	60	630	0	4685	110
js_typed_array_indexOf	/src/quickjs/quickjs.c	6	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'int']	70	0	931	227	93	619	0	4685	104
js_set_difference	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	71	0	257	39	17	626	0	4684	90
JS_ComputeMemoryUsage	/src/quickjs/quickjs.c	2	['N/A', 'N/A']	3	0	1041	153	50	6	0	73	67
js_array_toSorted	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	72	0	239	43	17	620	0	4653	63
js_std_file_printf	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	72	0	29	6	3	623	0	4642	61

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

Functions statically reachable by fuzzers

1266 / 1829

Cyclomatic complexity statically reachable by fuzzers

11395 / 15357

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.

fuzz/fuzz_regexp.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=['unicode_case1', 'cr_op', 're_string_list_free', 'lre_canonicalize', 're_parse_nested_class', 'cr_op1', 're_emit_char', 'cr_regexp_canonicalize', 'get_class_atom', 're_emit_range']

fuzz/fuzz_eval.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=['lre_js_is_ident_next', 'JS_CallInternal', 'js_std_add_helpers', 'JS_ConcatString3', 'JS_AddIntrinsicDate', 'js_binary_arith_slow', 'string_buffer_putc_slow', 'round_to_d', 'js_async_function_resume']

fuzz/fuzz_compile.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=['js_std_add_helpers', 're_string_list_free', 'js_async_function_call', 'JS_AddIntrinsicTypedArrays', 'js_date_constructor', 'js_for_of_start', 'ident_realloc', 'js_async_function_resume', 're_parse_term', 'get_class_atom']

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
exchange_func	33	14	42.42%	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
re_string_list_op	42	12	28.57%	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
re_emit_string_list	64	9	14.06%	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
JS_GetPropertyInternal	138	66	47.82%	['fuzz_eval', 'fuzz_compile']
JS_SetPropertyInternal	245	57	23.26%	['fuzz_eval', 'fuzz_compile']
JS_DefineProperty	236	89	37.71%	['fuzz_eval', 'fuzz_compile']
JS_GetOwnPropertyNamesInternal	180	96	53.33%	['fuzz_eval', 'fuzz_compile']
JS_GetOwnPropertyInternal	70	35	50.0%	['fuzz_eval', 'fuzz_compile']
JS_GetPropertyValue	66	26	39.39%	['fuzz_eval', 'fuzz_compile']
JS_ToInt64SatFree	38	13	34.21%	['fuzz_eval', 'fuzz_compile']
js_call_c_function	112	58	51.78%	['fuzz_eval', 'fuzz_compile']
JS_CallInternal	2580	1175	45.54%	['fuzz_eval', 'fuzz_compile']
js_for_in_prepare_prototype_chain_enum	52	23	44.23%	['fuzz_eval', 'fuzz_compile']
JS_GetIterator	31	15	48.38%	['fuzz_eval', 'fuzz_compile']
JS_IteratorNext2	31	17	54.83%	['fuzz_eval', 'fuzz_compile']
JS_ConcatString	72	26	36.11%	['fuzz_eval', 'fuzz_compile']
JS_CallConstructorInternal	40	15	37.5%	['fuzz_eval', 'fuzz_compile']
js_default_module_normalize_name	46	8	17.39%	['fuzz_eval', 'fuzz_compile']
js_inner_module_linking	130	69	53.07%	['fuzz_eval', 'fuzz_compile']
js_string_define_own_property	32	11	34.37%	['fuzz_eval', 'fuzz_compile']
js_regexp_constructor	78	27	34.61%	['fuzz_eval', 'fuzz_compile']
js_regexp_exec	185	97	52.43%	['fuzz_eval']
js_promise_resolve_function_call	41	19	46.34%	['fuzz_eval', 'fuzz_compile']
fulfill_or_reject_promise	32	15	46.87%	['fuzz_eval', 'fuzz_compile']
js_async_function_resume	45	20	44.44%	['fuzz_eval', 'fuzz_compile']
js_parse_directives	77	6	7.792%	['fuzz_eval', 'fuzz_compile']
js_parse_array_literal	84	38	45.23%	['fuzz_eval', 'fuzz_compile']
js_parse_assign_expr2	233	103	44.20%	['fuzz_eval', 'fuzz_compile']
js_parse_import	125	29	23.20%	['fuzz_eval', 'fuzz_compile']
emit_return	68	17	25.0%	['fuzz_eval', 'fuzz_compile']
instantiate_hoisted_definitions	111	53	47.74%	['fuzz_eval', 'fuzz_compile']
ss_check	33	17	51.51%	['fuzz_eval', 'fuzz_compile']
js_array_join	50	27	54.0%	['fuzz_eval', 'fuzz_compile']
u64toa_radix	31	4	12.90%	['fuzz_eval', 'fuzz_compile']
js_dtoa_max_len	39	15	38.46%	['fuzz_eval', 'fuzz_compile']
js_dtoa	172	91	52.90%	['fuzz_eval', 'fuzz_compile']
js_load_file	41	8	19.51%	['fuzz_eval', 'fuzz_compile']
js_module_loader	43	14	32.55%	['fuzz_eval', 'fuzz_compile']
js_os_poll	98	14	14.28%	['fuzz_eval', 'fuzz_compile']
set_array_length	70	13	18.57%	['fuzz_eval', 'fuzz_compile']
JS_ToInt32SatFree	41	22	53.65%	['fuzz_compile']
JS_ToArrayLengthFree	54	17	31.48%	['fuzz_eval', 'fuzz_compile']
js_strict_eq2	118	28	23.72%	['fuzz_eval', 'fuzz_compile']
js_dynamic_import	88	33	37.5%	['fuzz_eval', 'fuzz_compile']
js_append_enumerate	64	17	26.56%	['fuzz_eval', 'fuzz_compile']
js_bigint_pow	74	38	51.35%	['fuzz_eval', 'fuzz_compile']
js_bigint_float64_cmp	42	20	47.61%	['fuzz_eval', 'fuzz_compile']
js_eq_slow	113	37	32.74%	['fuzz_eval', 'fuzz_compile']
JS_LoadModuleInternal	36	15	41.66%	['fuzz_eval', 'fuzz_compile']
JS_WriteObjectRec	134	57	42.53%	['fuzz_compile']
JS_WriteModule	44	17	38.63%	['fuzz_compile']
JS_ReadObjectRec	107	43	40.18%	['fuzz_compile']
JS_ReadModule	103	25	24.27%	['fuzz_compile']
js_regexp_Symbol_replace	174	58	33.33%	['fuzz_compile']
js_date_constructor	56	17	30.35%	['fuzz_eval', 'fuzz_compile']
js_parse_destructuring_element	395	96	24.30%	['fuzz_compile']
js_parse_class	435	174	40.0%	['fuzz_compile']
js_parse_object_literal	106	12	11.32%	['fuzz_compile']
js_parse_delete	86	40	46.51%	['fuzz_compile']
js_parse_property_name	106	36	33.96%	['fuzz_compile']
emit_break	44	16	36.36%	['fuzz_compile']
resolve_pseudo_var	31	17	54.83%	['fuzz_compile']
js_error_constructor	64	19	29.68%	['fuzz_eval', 'fuzz_compile']
js_string_replace	101	23	22.77%	['fuzz_compile']

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/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/quickjs.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/./quickjs.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/quickjs-libc.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_eval.c	['fuzz_eval']	['fuzz_eval']
/src/quickjs/cutils.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/./libunicode.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/./list.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/./cutils.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/libunicode.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/dtoa.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_regexp.c	['fuzz_regexp']	['fuzz_regexp']
/src/quickjs/fuzz/fuzz_common.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']

Directories in report

Directory
/src/quickjs/./
/src/quickjs/
/src/quickjs/fuzz/