High level conclusions

Fuzzers reach 48.09% of cyclomatic complexity.

Fuzzers reach 52.97% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

1023 / 1931

Cyclomatic complexity statically reachable by fuzzers

7970 / 16570

Runtime code coverage of functions

931 / 1931

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	306	50.4%
gold	[1:9]	21	3.45%
yellow	[10:29]	27	4.44%
greenyellow	[30:49]	28	4.61%
lawngreen	50+	225	37.0%
All colors	607	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	238	unicode_case1	call site: 00238	unicode_prop_ops
35	198	cr_op	call site: 00198	unicode_prop
24	559	lre_exec_backtrack	call site: 00559	lre_canonicalize
18	171	re_string_list_free	call site: 00171	parse_unicode_property
16	384	re_parse_nested_class	call site: 00384	re_parse_class_set_operand
14	335	lre_canonicalize	call site: 00335	parse_class_string_disjunction
13	288	cr_op1	call site: 00288	re_string_list_canonicalize
12	592	lre_exec_backtrack	call site: 00592	lre_canonicalize
10	81	lre_parse_escape	call site: 00081	unicode_from_utf8
10	421	re_emit_char	call site: 00421	re_emit_range
10	532	lre_exec_backtrack	call site: 00532	lre_is_space
8	311	cr_regexp_canonicalize	call site: 00311	lre_case_conv_entry

Runtime coverage analysis

Covered functions

100

Functions that are reachable but not covered

41

Reachable functions

139

Percentage of reachable functions covered

70.5%

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	57
cutils.c	14
./cutils.h	14
./libunicode.h	10
libunicode.c	32

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	3761	69.3%
gold	[1:9]	191	3.52%
yellow	[10:29]	612	11.2%
greenyellow	[30:49]	53	0.97%
lawngreen	50+	804	14.8%
All colors	5421	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
402	4090	lre_is_id_continue	call site: 04090	js_regexp_set_internal
237	2877	JS_CallInternal	call site: 02877	js_unary_arith_slow
183	5053	js_std_add_helpers	call site: 05053	js_print
135	3212	js_async_function_resume	call site: 03212	js_promise_resolve
130	2404	JS_ConcatString3	call site: 02404	JS_DefinePropertyValue
106	2212	js_for_in_next	call site: 02212	js_for_of_start
104	3832	JS_AddIntrinsicDate	call site: 03832	js_Date_parse
94	4893	ident_realloc	call site: 04893	json_parse_value
81	2755	js_binary_arith_slow	call site: 02755	js_bigint_add
75	4636	JS_AddIntrinsicTypedArrays	call site: 04636	js_typed_array_constructor_obj
74	1711	JS_ToInt32	call site: 01711	JS_ToNumberFree
60	4005	dbuf_put_u32	call site: 04005	re_parse_disjunction

Runtime coverage analysis

Covered functions

650

Functions that are reachable but not covered

517

Reachable functions

989

Percentage of reachable functions covered

47.72%

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	722
./list.h	6
./cutils.h	28
./quickjs.h	23
dtoa.c	37
cutils.c	18
./libunicode.h	9
libunicode.c	32
libregexp.c	51
fuzz/fuzz_common.c	3
quickjs-libc.c	34

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	3216	54.7%
gold	[1:9]	92	1.56%
yellow	[10:29]	165	2.80%
greenyellow	[30:49]	398	6.77%
lawngreen	50+	2007	34.1%
All colors	5878	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
183	5053	js_std_add_helpers	call site: 05053	js_print
173	4156	re_string_list_free	call site: 04156	parse_class_string_disjunction
135	3212	js_async_function_resume	call site: 03212	js_promise_resolve
76	4893	ident_realloc	call site: 04893	json_parse_value
75	4636	JS_AddIntrinsicTypedArrays	call site: 04636	js_typed_array_constructor_obj
70	3834	js_date_constructor	call site: 03834	js_Date_parse
69	2248	js_for_of_start	call site: 02248	JS_GetPropertyInternal
61	2473	JS_CallInternal	call site: 02473	JS_GetPropertyValue
46	4335	get_class_atom	call site: 04335	re_parse_class_set_operand
45	4090	lre_is_id_continue	call site: 04090	re_parse_disjunction
45	4531	JS_AddIntrinsicMapSet	call site: 04531	JS_CreateFromConstructor
44	3103	js_operator_delete	call site: 03103	JS_DeleteGlobalVar

Runtime coverage analysis

Covered functions

905

Functions that are reachable but not covered

379

Reachable functions

1052

Percentage of reachable functions covered

63.97%

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	784
./list.h	6
./cutils.h	29
./quickjs.h	23
dtoa.c	37
cutils.c	18
./libunicode.h	9
libunicode.c	32
libregexp.c	51
fuzz/fuzz_common.c	3
quickjs-libc.c	34

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']	96	0	334	57	20	831	0	7672	2758
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	70	0	712	120	49	663	0	5383	309
js_json_to_str	/src/quickjs/quickjs.c	5	['N/A', 'N/A', 'size_t', 'size_t', 'N/A']	75	0	775	140	54	652	3	5081	252
js_iterator_helper_next	/src/quickjs/quickjs.c	7	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'N/A', 'int']	65	0	884	142	52	627	0	4909	132
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	69	0	150	31	13	645	0	4936	127
js_array_from_async_resume	/src/quickjs/quickjs.c	4	['N/A', 'size_t', 'size_t', 'N/A']	79	0	711	114	43	637	6	4920	116
js_typed_array_indexOf	/src/quickjs/quickjs.c	6	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'int']	71	0	930	227	93	630	0	4894	115

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

Functions statically reachable by fuzzers

1276 / 1931

Cyclomatic complexity statically reachable by fuzzers

11680 / 16570

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', 'lre_exec_backtrack', 're_string_list_free', 're_parse_nested_class', 'lre_canonicalize', 'cr_op1', 'lre_parse_escape', 're_emit_char']

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_is_id_continue', 'JS_CallInternal', 'js_std_add_helpers', 'js_async_function_resume', 'JS_ConcatString3', 'js_for_in_next', 'JS_AddIntrinsicDate', 'ident_realloc', 'js_binary_arith_slow', 'JS_AddIntrinsicTypedArrays']

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_resume', 'ident_realloc', 'JS_AddIntrinsicTypedArrays', 'js_date_constructor', 'js_for_of_start', 'JS_CallInternal', 'get_class_atom', 'lre_is_id_continue']

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
unicode_to_utf8	32	16	50.0%	['fuzz_compile', 'fuzz_regexp', 'fuzz_eval']
exchange_func	33	14	42.42%	['fuzz_compile', 'fuzz_regexp', 'fuzz_eval']
re_parse_nested_class	142	69	48.59%	['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_dtoa_max_len	39	15	38.46%	['fuzz_compile', 'fuzz_eval']
js_os_poll	97	12	12.37%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyInternal	138	71	51.44%	['fuzz_compile', 'fuzz_eval']
JS_SetPropertyInternal	251	61	24.30%	['fuzz_compile', 'fuzz_eval']
JS_DefineProperty	262	89	33.96%	['fuzz_compile', 'fuzz_eval']
JS_ToObject	46	24	52.17%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyNamesInternal	180	96	53.33%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyInternal	70	31	44.28%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyValue	69	26	37.68%	['fuzz_compile', 'fuzz_eval']
delete_property	83	44	53.01%	['fuzz_compile', 'fuzz_eval']
JS_ToInt64SatFree	54	13	24.07%	['fuzz_compile', 'fuzz_eval']
js_call_c_function	115	62	53.91%	['fuzz_compile', 'fuzz_eval']
JS_CallInternal	2791	1408	50.44%	['fuzz_compile', 'fuzz_eval']
js_build_mapped_arguments	45	19	42.22%	['fuzz_compile', 'fuzz_eval']
js_for_in_prepare_prototype_chain_enum	52	23	44.23%	['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_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_destructuring_element	403	148	36.72%	['fuzz_compile', 'fuzz_eval']
js_parse_property_name	106	51	48.11%	['fuzz_compile', 'fuzz_eval']
put_lvalue	112	53	47.32%	['fuzz_compile', 'fuzz_eval']
js_parse_import	125	36	28.79%	['fuzz_compile', 'fuzz_eval']
js_parse_statement_or_decl	628	316	50.31%	['fuzz_compile', 'fuzz_eval']
emit_return	68	17	25.0%	['fuzz_compile', 'fuzz_eval']
add_global_variables	71	31	43.66%	['fuzz_compile', 'fuzz_eval']
ss_check	33	17	51.51%	['fuzz_compile', 'fuzz_eval']
js_error_constructor	64	25	39.06%	['fuzz_compile', 'fuzz_eval']
js_array_join	53	23	43.39%	['fuzz_compile', 'fuzz_eval']
u64toa_radix	31	4	12.90%	['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_GetIterator	31	12	38.70%	['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_strict_eq2	114	44	38.59%	['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_eq_slow	119	65	54.62%	['fuzz_compile', 'fuzz_eval']
js_operator_typeof	48	12	25.0%	['fuzz_compile', 'fuzz_eval']
JS_LoadModuleInternal	36	15	41.66%	['fuzz_compile', 'fuzz_eval']
JS_WriteObjectRec	137	57	41.60%	['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_compile_regexp	69	34	49.27%	['fuzz_compile', 'fuzz_eval']
js_regexp_exec	196	101	51.53%	['fuzz_compile']
js_string_GetSubstitution	103	26	25.24%	['fuzz_compile']
js_date_constructor	56	17	30.35%	['fuzz_compile', 'fuzz_eval']
js_parse_class	435	184	42.29%	['fuzz_compile']
js_parse_array_literal	84	39	46.42%	['fuzz_compile']
js_parse_delete	86	40	46.51%	['fuzz_compile']
js_number_toString	35	16	45.71%	['fuzz_compile']
js_string_replace	99	23	23.23%	['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/dtoa.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/./list.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/./libunicode.h	['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/fuzz/fuzz_regexp.c	['fuzz_regexp']	['fuzz_regexp']
/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/quickjs.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/libunicode.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']
/src/quickjs/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/./cutils.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']

Directories in report

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