High level conclusions

Fuzzers reach 49.60% of cyclomatic complexity.

Fuzzers reach 54.53% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

999 / 1832

Cyclomatic complexity statically reachable by fuzzers

7650 / 15423

Runtime code coverage of functions

882 / 1832

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]	5	0.83%
lawngreen	50+	370	61.9%
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	3641	69.7%
gold	[1:9]	356	6.82%
yellow	[10:29]	655	12.5%
greenyellow	[30:49]	75	1.43%
lawngreen	50+	490	9.39%
All colors	5217	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	3931	lre_js_is_ident_next	call site: 03931	re_parse_disjunction
188	2821	JS_CallInternal	call site: 02821	js_binary_logic_slow
182	4852	js_std_add_helpers	call site: 04852	js_print
136	2291	JS_ConcatString3	call site: 02291	JS_DefinePropertyValue
104	3678	JS_AddIntrinsicDate	call site: 03678	js_Date_parse
81	2630	js_binary_arith_slow	call site: 02630	js_bigint_add
65	4722	ident_realloc	call site: 04722	json_parse_value
64	799	round_to_d	call site: 00799	js_new_string8_len
56	3076	js_async_function_resume	call site: 03076	js_promise_resolve
53	2227	JS_CallInternal	call site: 02227	JS_NewSymbolFromAtom
53	4253	re_parse_term	call site: 04253	re_emit_goto
49	3245	JS_EvalFunctionInternal	call site: 03245	JS_ThrowTypeError

Runtime coverage analysis

Covered functions

665

Functions that are reachable but not covered

476

Reachable functions

964

Percentage of reachable functions covered

50.62%

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	702
./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	3459	61.0%
gold	[1:9]	233	4.11%
yellow	[10:29]	505	8.91%
greenyellow	[30:49]	158	2.78%
lawngreen	50+	1311	23.1%
All colors	5666	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	4852	js_std_add_helpers	call site: 04852	js_print
173	3989	re_string_list_free	call site: 03989	parse_class_string_disjunction
106	2903	JS_CallInternal	call site: 02903	js_operator_in
104	3678	JS_AddIntrinsicDate	call site: 03678	js_Date_parse
77	3133	js_async_function_call	call site: 03133	JS_NewCFunctionData
74	4469	JS_AddIntrinsicTypedArrays	call site: 04469	js_typed_array_constructor_obj
72	2132	JS_GetIterator	call site: 02132	JS_GetIterator2
65	4722	ident_realloc	call site: 04722	json_parse_value
61	2360	JS_CallInternal	call site: 02360	JS_GetPropertyValue
56	3076	js_async_function_resume	call site: 03076	js_promise_resolve
53	4253	re_parse_term	call site: 04253	re_emit_goto
52	3869	re_parse_term	call site: 03869	re_parse_disjunction

Runtime coverage analysis

Covered functions

811

Functions that are reachable but not covered

414

Reachable functions

1027

Percentage of reachable functions covered

59.69%

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	764
./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	7453	2696
js_json_stringify	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	75	0	20	3	2	647	0	4942	306
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	68	0	777	127	51	650	0	5154	207
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	68	0	155	31	13	636	0	4776	126
js_os_exec	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	70	0	743	161	60	632	0	4735	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	621	0	4735	104
js_set_difference	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	71	0	257	39	17	628	0	4734	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	622	0	4703	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	625	0	4692	61

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

Functions statically reachable by fuzzers

1266 / 1832

Cyclomatic complexity statically reachable by fuzzers

11456 / 15423

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', 'ident_realloc', '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_CallInternal', 'JS_AddIntrinsicDate', 'js_async_function_call', 'JS_AddIntrinsicTypedArrays', 'JS_GetIterator', 'ident_realloc', 'js_async_function_resume']

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_eval', 'fuzz_regexp']
re_string_list_op	42	12	28.57%	['fuzz_compile', 'fuzz_eval', 'fuzz_regexp']
re_emit_string_list	64	9	14.06%	['fuzz_compile', 'fuzz_eval', 'fuzz_regexp']
js_os_poll	98	14	14.28%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyInternal	138	66	47.82%	['fuzz_compile', 'fuzz_eval']
JS_HasProperty	37	20	54.05%	['fuzz_compile', 'fuzz_eval']
JS_SetPropertyInternal	247	61	24.69%	['fuzz_compile', 'fuzz_eval']
JS_DefineProperty	262	89	33.96%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyNamesInternal	180	96	53.33%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyInternal	70	30	42.85%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyValue	66	26	39.39%	['fuzz_compile', 'fuzz_eval']
delete_property	78	35	44.87%	['fuzz_compile', 'fuzz_eval']
JS_ToBoolFree	59	27	45.76%	['fuzz_compile', 'fuzz_eval']
JS_ToInt64SatFree	38	13	34.21%	['fuzz_compile', 'fuzz_eval']
js_call_c_function	112	56	50.0%	['fuzz_compile', 'fuzz_eval']
JS_CallInternal	2583	922	35.69%	['fuzz_compile', 'fuzz_eval']
js_closure	42	23	54.76%	['fuzz_compile', 'fuzz_eval']
js_for_in_prepare_prototype_chain_enum	52	23	44.23%	['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_ConcatString	72	26	36.11%	['fuzz_compile', 'fuzz_eval']
js_binary_arith_slow	178	87	48.87%	['fuzz_compile', 'fuzz_eval']
js_unary_arith_slow	134	44	32.83%	['fuzz_compile', 'fuzz_eval']
js_binary_logic_slow	153	80	52.28%	['fuzz_compile', 'fuzz_eval']
JS_CallConstructorInternal	40	15	37.5%	['fuzz_compile', 'fuzz_eval']
simple_next_token	81	44	54.32%	['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	78	27	34.61%	['fuzz_compile', 'fuzz_eval']
js_regexp_exec	185	97	52.43%	['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_string	120	63	52.5%	['fuzz_compile', 'fuzz_eval']
js_parse_directives	77	6	7.792%	['fuzz_compile', 'fuzz_eval']
js_parse_postfix_expr	579	299	51.64%	['fuzz_compile', 'fuzz_eval']
js_parse_array_literal	84	31	36.90%	['fuzz_eval']
js_parse_assign_expr2	236	51	21.61%	['fuzz_compile', 'fuzz_eval']
put_lvalue	109	47	43.11%	['fuzz_compile', 'fuzz_eval']
js_parse_import	125	29	23.20%	['fuzz_compile', 'fuzz_eval']
js_parse_statement_or_decl	626	282	45.04%	['fuzz_compile', 'fuzz_eval']
emit_return	68	17	25.0%	['fuzz_compile', 'fuzz_eval']
resolve_scope_var	423	208	49.17%	['fuzz_compile', 'fuzz_eval']
instantiate_hoisted_definitions	85	46	54.11%	['fuzz_compile', 'fuzz_eval']
ss_check	33	17	51.51%	['fuzz_compile', 'fuzz_eval']
js_array_join	50	27	54.0%	['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	29	16.86%	['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']
set_array_length	70	13	18.57%	['fuzz_compile', 'fuzz_eval']
JS_ToInt32SatFree	41	22	53.65%	['fuzz_compile']
JS_ToArrayLengthFree	54	17	31.48%	['fuzz_compile', 'fuzz_eval']
js_bigint_to_string1	85	8	9.411%	['fuzz_compile', 'fuzz_eval']
js_strict_eq2	118	18	15.25%	['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	37	50.0%	['fuzz_compile', 'fuzz_eval']
js_relational_slow	124	56	45.16%	['fuzz_compile', 'fuzz_eval']
js_eq_slow	113	36	31.85%	['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	43	40.18%	['fuzz_compile']
JS_ReadModule	103	25	24.27%	['fuzz_compile']
js_parse_function_decl2	463	199	42.98%	['fuzz_compile']
js_parse_destructuring_element	403	85	21.09%	['fuzz_compile']
js_parse_class	435	174	40.0%	['fuzz_compile']
js_parse_object_literal	106	12	11.32%	['fuzz_compile']
js_parse_property_name	106	36	33.96%	['fuzz_compile']
resolve_pseudo_var	31	17	54.83%	['fuzz_compile']
js_function_toString	38	10	26.31%	['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/quickjs.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['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/quickjs-libc.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/cutils.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_eval.c	['fuzz_eval']	['fuzz_eval']
/src/quickjs/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/./list.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/./cutils.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/./quickjs.h	['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']
/src/quickjs/./libunicode.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]

Directories in report

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