High level conclusions

Fuzzers reach 54.16% code coverage.

Fuzzers reach 49.40% of cyclomatic complexity.

Fuzzers reach 54.38% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

992 / 1824

Cyclomatic complexity statically reachable by fuzzers

7567 / 15315

Runtime code coverage of functions

988 / 1824

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	35.9%
gold	[1:9]	5	0.84%
yellow	[10:29]	10	1.68%
greenyellow	[30:49]	1	0.16%
lawngreen	50+	363	61.3%
All colors	592	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	220	unicode_case1	call site: 00220	unicode_prop_ops
35	180	cr_op	call site: 00180	unicode_prop
18	153	re_string_list_free	call site: 00153	parse_unicode_property
14	317	lre_canonicalize	call site: 00317	parse_class_string_disjunction
14	366	re_parse_nested_class	call site: 00366	re_parse_class_set_operand
13	270	cr_op1	call site: 00270	re_string_list_canonicalize
10	403	re_emit_char	call site: 00403	re_emit_range
8	293	cr_regexp_canonicalize	call site: 00293	lre_case_conv_entry
8	338	get_class_atom	call site: 00338	re_string_list_canonicalize
7	395	re_emit_range	call site: 00395	rqsort
6	172	cr_add_interval	call site: 00172	cr_op
4	359	re_string_list_op	call site: 00359	re_string_find2

Runtime coverage analysis

Covered functions

102

Functions that are reachable but not covered

32

Reachable functions

132

Percentage of reachable functions covered

75.76%

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	13
./cutils.h	13
./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	3599	69.5%
gold	[1:9]	419	8.09%
yellow	[10:29]	571	11.0%
greenyellow	[30:49]	59	1.14%
lawngreen	50+	526	10.1%
All colors	5174	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	3890	lre_js_is_ident_next	call site: 03890	re_parse_disjunction
188	2787	JS_CallInternal	call site: 02787	js_binary_logic_slow
181	4810	js_std_add_helpers	call site: 04810	js_print
136	2257	JS_ConcatString3	call site: 02257	JS_DefinePropertyValue
103	3645	JS_AddIntrinsicDate	call site: 03645	js_Date_parse
81	2596	js_binary_arith_slow	call site: 02596	js_bigint_add
75	4670	string_buffer_putc_slow	call site: 04670	json_parse_value
67	738	round_to_d	call site: 00738	js_new_string8_len
56	3044	js_async_function_resume	call site: 03044	js_promise_resolve
53	4212	re_parse_term	call site: 04212	re_emit_goto
49	3213	JS_EvalFunctionInternal	call site: 03213	JS_ThrowTypeError
48	4427	JS_AddIntrinsicTypedArrays	call site: 04427	js_typed_array_constructor_obj

Runtime coverage analysis

Covered functions

666

Functions that are reachable but not covered

471

Reachable functions

957

Percentage of reachable functions covered

50.78%

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	698
./list.h	6
./cutils.h	27
./quickjs.h	22
dtoa.c	37
cutils.c	17
./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	2754	48.9%
gold	[1:9]	84	1.49%
yellow	[10:29]	35	0.62%
greenyellow	[30:49]	29	0.51%
lawngreen	50+	2723	48.4%
All colors	5625	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
77	3101	js_async_function_call	call site: 03101	JS_NewCFunctionData
69	2106	js_for_of_start	call site: 02106	JS_GetPropertyInternal
65	4680	ident_realloc	call site: 04680	json_parse_value
56	3044	js_async_function_resume	call site: 03044	js_promise_resolve
48	4427	JS_AddIntrinsicTypedArrays	call site: 04427	js_typed_array_constructor_obj
47	4015	unicode_case1	call site: 04015	unicode_prop_ops
45	4324	JS_AddIntrinsicMapSet	call site: 04324	js_create_from_ctor
40	2879	js_operator_in	call site: 02879	js_operator_private_in
35	3975	cr_op	call site: 03975	unicode_prop
34	2939	JS_CallInternal	call site: 02939	JS_ToPropertyKey
33	4374	JS_AddIntrinsicTypedArrays	call site: 04374	js_array_buffer_constructor0
33	5288	JS_WriteArray	call site: 05288	JS_WriteObjectTag

Runtime coverage analysis

Covered functions

979

Functions that are reachable but not covered

294

Reachable functions

1020

Percentage of reachable functions covered

71.18%

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	760
./list.h	6
./cutils.h	28
./quickjs.h	22
dtoa.c	37
cutils.c	17
./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']	94	0	341	58	20	814	0	7369	2685
js_json_stringify	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	74	0	20	3	2	643	0	4860	291
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	67	0	777	127	51	646	0	5087	207
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	67	0	155	31	13	630	0	4704	126
js_os_exec	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	69	0	743	161	60	628	0	4668	110
js_typed_array_indexOf	/src/quickjs/quickjs.c	6	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'int']	69	0	931	227	93	617	0	4668	104
js_set_difference	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	70	0	257	39	17	624	0	4667	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']	71	0	239	43	17	618	0	4636	63
js_std_file_printf	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	71	0	29	6	3	621	0	4625	61

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

Functions statically reachable by fuzzers

1261 / 1824

Cyclomatic complexity statically reachable by fuzzers

11347 / 15315

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', 're_parse_term']

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_async_function_call', 'js_for_of_start', 'ident_realloc', 'js_async_function_resume', 'JS_AddIntrinsicTypedArrays', 'unicode_case1', 'JS_AddIntrinsicMapSet', 'js_operator_in', 'cr_op', 'JS_CallInternal']

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_compile', 'fuzz_regexp', 'fuzz_eval']
re_string_list_op	42	12	28.57%	['fuzz_compile', 'fuzz_regexp', 'fuzz_eval']
re_emit_string_list	64	9	14.06%	['fuzz_compile', 'fuzz_regexp', 'fuzz_eval']
js_os_poll	98	14	14.28%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyInternal	138	75	54.34%	['fuzz_compile', 'fuzz_eval']
JS_SetPropertyInternal	245	77	31.42%	['fuzz_compile', 'fuzz_eval']
JS_DefineProperty	236	92	38.98%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyInternal	70	35	50.0%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyValue	66	30	45.45%	['fuzz_compile', 'fuzz_eval']
JS_ToInt64SatFree	38	13	34.21%	['fuzz_compile', 'fuzz_eval']
JS_CallInternal	2577	1274	49.43%	['fuzz_compile', 'fuzz_eval']
JS_GetIterator	31	15	48.38%	['fuzz_compile', 'fuzz_eval']
JS_IteratorNext2	31	17	54.83%	['fuzz_compile', 'fuzz_eval']
JS_CallConstructorInternal	40	16	40.0%	['fuzz_compile', 'fuzz_eval']
js_default_module_normalize_name	46	8	17.39%	['fuzz_compile', 'fuzz_eval']
js_inner_module_linking	130	69	53.07%	['fuzz_compile', 'fuzz_eval']
js_string_define_own_property	32	11	34.37%	['fuzz_compile', 'fuzz_eval']
js_regexp_constructor	73	39	53.42%	['fuzz_compile', 'fuzz_eval']
js_regexp_exec	185	99	53.51%	['fuzz_compile', 'fuzz_eval']
js_promise_resolve_function_call	41	19	46.34%	['fuzz_compile', 'fuzz_eval']
fulfill_or_reject_promise	32	15	46.87%	['fuzz_compile', 'fuzz_eval']
js_async_function_resume	45	20	44.44%	['fuzz_compile', 'fuzz_eval']
js_parse_directives	77	6	7.792%	['fuzz_compile', 'fuzz_eval']
js_parse_object_literal	106	37	34.90%	['fuzz_compile', 'fuzz_eval']
js_parse_assign_expr2	233	109	46.78%	['fuzz_compile', 'fuzz_eval']
js_parse_property_name	106	52	49.05%	['fuzz_compile', 'fuzz_eval']
js_parse_import	125	29	23.20%	['fuzz_compile', 'fuzz_eval']
emit_return	68	17	25.0%	['fuzz_compile', 'fuzz_eval']
ss_check	33	17	51.51%	['fuzz_compile', 'fuzz_eval']
js_array_join	50	27	54.0%	['fuzz_compile', 'fuzz_eval']
u64toa_radix	31	4	12.90%	['fuzz_compile', 'fuzz_eval']
js_dtoa_max_len	39	15	38.46%	['fuzz_compile', 'fuzz_eval']
js_dtoa	172	94	54.65%	['fuzz_compile', 'fuzz_eval']
js_load_file	41	8	19.51%	['fuzz_compile', 'fuzz_eval']
js_module_loader	43	14	32.55%	['fuzz_compile', 'fuzz_eval']
JS_SetPrototypeInternal	86	36	41.86%	['fuzz_compile', 'fuzz_eval']
set_array_length	70	13	18.57%	['fuzz_compile', 'fuzz_eval']
JS_SetPropertyValue	112	22	19.64%	['fuzz_compile', 'fuzz_eval']
JS_ToInt32SatFree	41	22	53.65%	['fuzz_compile']
JS_ToArrayLengthFree	54	17	31.48%	['fuzz_compile', 'fuzz_eval']
js_print_value	116	26	22.41%	['fuzz_compile', 'fuzz_eval']
js_print_object	223	71	31.83%	['fuzz_compile', 'fuzz_eval']
js_strict_eq2	118	43	36.44%	['fuzz_compile', 'fuzz_eval']
js_dynamic_import	88	33	37.5%	['fuzz_compile', 'fuzz_eval']
js_append_enumerate	64	17	26.56%	['fuzz_compile', 'fuzz_eval']
js_bigint_pow	74	38	51.35%	['fuzz_compile', 'fuzz_eval']
js_bigint_float64_cmp	42	20	47.61%	['fuzz_compile', 'fuzz_eval']
JS_LoadModuleInternal	36	15	41.66%	['fuzz_compile', 'fuzz_eval']
JS_WriteObjectRec	134	57	42.53%	['fuzz_compile']
JS_WriteModule	44	17	38.63%	['fuzz_compile']
JS_ReadObjectRec	107	44	41.12%	['fuzz_compile']
JS_ReadModule	103	31	30.09%	['fuzz_compile']
js_regexp_Symbol_replace	174	58	33.33%	['fuzz_compile']
js_regexp_Symbol_match	73	26	35.61%	['fuzz_compile']
js_obj_to_desc	75	25	33.33%	['fuzz_compile']
js_function_constructor	60	32	53.33%	['fuzz_compile', 'fuzz_eval']
js_date_constructor	61	17	27.86%	['fuzz_compile', 'fuzz_eval']
js_date_parse_isostring	54	11	20.37%	['fuzz_compile', 'fuzz_eval']
js_date_parse_otherstring	140	42	30.0%	['fuzz_compile', 'fuzz_eval']
js_parse_destructuring_element	395	141	35.69%	['fuzz_compile']
js_parse_class	435	184	42.29%	['fuzz_compile']
js_parse_delete	86	40	46.51%	['fuzz_compile']
emit_break	44	16	36.36%	['fuzz_compile']
resolve_pseudo_var	31	17	54.83%	['fuzz_compile']
js_error_constructor	64	28	43.75%	['fuzz_compile', 'fuzz_eval']
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/cutils.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/quickjs-libc.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_regexp.c	['fuzz_regexp']	['fuzz_regexp']
/src/quickjs/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/./libunicode.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/./quickjs.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/fuzz/fuzz_eval.c	['fuzz_eval']	['fuzz_eval']
/src/quickjs/quickjs.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/./list.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/dtoa.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_common.c	['fuzz_eval', 'fuzz_compile']	['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']

Directories in report

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