High level conclusions

Fuzzers reach 49.45% of cyclomatic complexity.

Fuzzers reach 54.28% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

1001 / 1844

Cyclomatic complexity statically reachable by fuzzers

7710 / 15591

Runtime code coverage of functions

883 / 1844

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	444	75.7%
gold	[1:9]	42	7.16%
yellow	[10:29]	35	5.97%
greenyellow	[30:49]	20	3.41%
lawngreen	50+	45	7.67%
All colors	586	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
87	185	cr_op	call site: 00185	unicode_prop
61	275	cr_op1	call site: 00275	parse_class_string_disjunction
58	526	lre_exec_backtrack	call site: 00526	lre_canonicalize
38	75	re_parse_term	call site: 00075	re_parse_group_name
27	343	get_class_atom	call site: 00343	get_class_atom
25	158	re_string_list_free	call site: 00158	parse_unicode_property
18	119	re_parse_term	call site: 00119	re_has_named_captures
16	371	re_parse_nested_class	call site: 00371	re_parse_class_set_operand
13	408	re_emit_char	call site: 00408	re_emit_range
13	509	lre_exec_backtrack	call site: 00509	is_line_terminator
10	397	re_emit_range	call site: 00397	rqsort
8	443	re_emit_goto	call site: 00443	re_emit_goto_u8

Runtime coverage analysis

Covered functions

64

Functions that are reachable but not covered

71

Reachable functions

135

Percentage of reachable functions covered

47.41%

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_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	3181	55.8%
gold	[1:9]	48	0.84%
yellow	[10:29]	66	1.15%
greenyellow	[30:49]	510	8.94%
lawngreen	50+	1894	33.2%
All colors	5699	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	4879	js_std_add_helpers	call site: 04879	js_print
173	4011	re_string_list_free	call site: 04011	parse_class_string_disjunction
77	3139	js_async_function_call	call site: 03139	JS_NewCFunctionData
74	4496	JS_AddIntrinsicTypedArrays	call site: 04496	js_typed_array_constructor_obj
70	3702	js_date_constructor	call site: 03702	js_Date_parse
69	2133	js_for_of_start	call site: 02133	JS_GetPropertyInternal
65	4749	ident_realloc	call site: 04749	json_parse_value
61	2358	JS_CallInternal	call site: 02358	JS_GetPropertyValue
56	3082	js_async_function_resume	call site: 03082	js_promise_resolve
46	4190	get_class_atom	call site: 04190	re_parse_class_set_operand
45	2521	JS_ConcatString2	call site: 02521	js_new_string_rope
45	4393	JS_AddIntrinsicMapSet	call site: 04393	js_create_from_ctor

Runtime coverage analysis

Covered functions

892

Functions that are reachable but not covered

375

Reachable functions

1029

Percentage of reachable functions covered

63.56%

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	766
./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

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	2941	56.0%
gold	[1:9]	83	1.58%
yellow	[10:29]	70	1.33%
greenyellow	[30:49]	430	8.19%
lawngreen	50+	1720	32.7%
All colors	5244	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	4879	js_std_add_helpers	call site: 04879	js_print
87	4038	cr_op	call site: 04038	unicode_prop
77	3139	js_async_function_call	call site: 03139	JS_NewCFunctionData
74	4496	JS_AddIntrinsicTypedArrays	call site: 04496	js_typed_array_constructor_obj
70	3702	js_date_constructor	call site: 03702	js_Date_parse
69	2133	js_for_of_start	call site: 02133	JS_GetPropertyInternal
65	4749	ident_realloc	call site: 04749	json_parse_value
61	2358	JS_CallInternal	call site: 02358	JS_GetPropertyValue
56	3082	js_async_function_resume	call site: 03082	js_promise_resolve
56	4128	cr_op1	call site: 04128	parse_class_string_disjunction
45	2521	JS_ConcatString2	call site: 02521	js_new_string_rope
45	4393	JS_AddIntrinsicMapSet	call site: 04393	js_create_from_ctor

Runtime coverage analysis

Covered functions

902

Functions that are reachable but not covered

347

Reachable functions

966

Percentage of reachable functions covered

64.08%

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	704
./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

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	819	0	7494	2714
js_json_stringify	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	75	0	20	3	2	647	0	4965	306
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	69	0	767	125	50	654	0	5215	250
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	68	0	155	31	13	636	0	4799	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	4758	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	4758	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	4757	90
JS_ComputeMemoryUsage	/src/quickjs/quickjs.c	2	['N/A', 'N/A']	3	0	1108	163	54	6	0	77	71
js_array_toSorted	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	72	0	239	43	17	622	0	4726	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	4715	61

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

Functions statically reachable by fuzzers

1273 / 1844

Cyclomatic complexity statically reachable by fuzzers

11581 / 15591

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=['cr_op', 'cr_op1', 'lre_exec_backtrack', 're_parse_term', 'get_class_atom', 're_string_list_free', 're_parse_nested_class', 're_emit_char']

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_CallInternal', 'js_async_function_resume', 'get_class_atom']

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=['js_std_add_helpers', 'cr_op', 'js_async_function_call', 'JS_AddIntrinsicTypedArrays', 'js_date_constructor', 'js_for_of_start', 'ident_realloc', 'JS_CallInternal', 'js_async_function_resume', 'cr_op1']

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
lre_parse_escape	102	24	23.52%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
re_parse_term	455	232	50.98%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
re_parse_nested_class	142	41	28.87%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
re_emit_string_list	64	9	14.06%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
lre_exec_backtrack	440	126	28.63%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
unicode_to_utf8	32	16	50.0%	['fuzz_eval', 'fuzz_regexp', 'fuzz_compile']
exchange_func	33	9	27.27%	['fuzz_eval', 'fuzz_regexp', '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']
JS_GetPropertyInternal	138	68	49.27%	['fuzz_eval', 'fuzz_compile']
JS_SetPropertyInternal	247	64	25.91%	['fuzz_eval', 'fuzz_compile']
JS_DefineProperty	262	89	33.96%	['fuzz_eval', 'fuzz_compile']
JS_GetOwnPropertyNamesInternal	180	96	53.33%	['fuzz_eval', 'fuzz_compile']
JS_GetOwnPropertyInternal	70	31	44.28%	['fuzz_eval', 'fuzz_compile']
JS_GetPropertyValue	69	26	37.68%	['fuzz_eval', 'fuzz_compile']
set_array_length	70	13	18.57%	['fuzz_eval', 'fuzz_compile']
delete_property	83	41	49.39%	['fuzz_eval', 'fuzz_compile']
JS_ToInt32SatFree	41	22	53.65%	['fuzz_eval', 'fuzz_compile']
JS_ToInt64SatFree	38	13	34.21%	['fuzz_eval', 'fuzz_compile']
JS_ToArrayLengthFree	54	17	31.48%	['fuzz_eval', 'fuzz_compile']
js_strict_eq2	118	28	23.72%	['fuzz_eval', 'fuzz_compile']
js_call_c_function	112	57	50.89%	['fuzz_eval', 'fuzz_compile']
JS_CallInternal	2590	1117	43.12%	['fuzz_eval', 'fuzz_compile']
js_dynamic_import	88	33	37.5%	['fuzz_eval', 'fuzz_compile']
js_for_in_prepare_prototype_chain_enum	52	23	44.23%	['fuzz_eval', 'fuzz_compile']
JS_GetIterator	31	12	38.70%	['fuzz_eval', 'fuzz_compile']
js_append_enumerate	64	17	26.56%	['fuzz_eval', 'fuzz_compile']
JS_ConcatString	72	25	34.72%	['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_CallConstructorInternal	40	16	40.0%	['fuzz_eval', 'fuzz_compile']
JS_LoadModuleInternal	36	15	41.66%	['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_WriteObjectRec	134	57	42.53%	['fuzz_eval', 'fuzz_compile']
JS_WriteModule	44	17	38.63%	['fuzz_eval', 'fuzz_compile']
JS_ReadObjectRec	107	43	40.18%	['fuzz_eval', 'fuzz_compile']
JS_ReadModule	103	25	24.27%	['fuzz_eval', 'fuzz_compile']
JS_ToObject	46	24	52.17%	['fuzz_eval', 'fuzz_compile']
js_string_define_own_property	32	11	34.37%	['fuzz_eval', 'fuzz_compile']
js_compile_regexp	69	34	49.27%	['fuzz_eval', 'fuzz_compile']
js_regexp_exec	182	98	53.84%	['fuzz_eval', 'fuzz_compile']
js_string_GetSubstitution	103	26	25.24%	['fuzz_eval', 'fuzz_compile']
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_date_constructor	56	17	30.35%	['fuzz_eval', 'fuzz_compile']
js_parse_directives	77	6	7.792%	['fuzz_eval', 'fuzz_compile']
js_parse_function_decl2	463	221	47.73%	['fuzz_eval', 'fuzz_compile']
js_parse_skip_parens_token	104	56	53.84%	['fuzz_eval', 'fuzz_compile']
js_parse_destructuring_element	403	96	23.82%	['fuzz_eval', 'fuzz_compile']
js_parse_class	435	174	40.0%	['fuzz_eval', 'fuzz_compile']
js_parse_object_literal	106	12	11.32%	['fuzz_eval', 'fuzz_compile']
js_parse_array_literal	84	24	28.57%	['fuzz_eval', 'fuzz_compile']
js_parse_assign_expr2	236	94	39.83%	['fuzz_eval', 'fuzz_compile']
js_parse_delete	86	40	46.51%	['fuzz_eval', 'fuzz_compile']
js_parse_property_name	106	36	33.96%	['fuzz_eval', 'fuzz_compile']
put_lvalue	109	47	43.11%	['fuzz_eval', 'fuzz_compile']
js_parse_import	125	29	23.20%	['fuzz_eval', 'fuzz_compile']
js_parse_statement_or_decl	626	298	47.60%	['fuzz_eval', 'fuzz_compile']
is_let	36	6	16.66%	['fuzz_eval', 'fuzz_compile']
emit_return	68	17	25.0%	['fuzz_eval', 'fuzz_compile']
resolve_scope_var	425	213	50.11%	['fuzz_eval', 'fuzz_compile']
resolve_pseudo_var	31	17	54.83%	['fuzz_eval', 'fuzz_compile']
ss_check	33	17	51.51%	['fuzz_eval', 'fuzz_compile']
js_error_constructor	64	19	29.68%	['fuzz_eval', 'fuzz_compile']
js_array_join	50	23	46.0%	['fuzz_eval', 'fuzz_compile']
js_string_replace	99	23	23.23%	['fuzz_eval', '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.h	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']	[]
/src/quickjs/fuzz/fuzz_regexp.c	['fuzz_regexp']	['fuzz_regexp']
/src/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']
/src/quickjs/quickjs.c	['fuzz_compile', 'fuzz_eval']	['fuzz_compile', 'fuzz_eval']
/src/quickjs/./list.h	['fuzz_compile', 'fuzz_eval']	[]
/src/quickjs/./quickjs.h	['fuzz_compile', 'fuzz_eval']	[]
/src/quickjs/./libunicode.h	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']	[]
/src/quickjs/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/quickjs-libc.c	['fuzz_compile', 'fuzz_eval']	['fuzz_compile', 'fuzz_eval']
/src/quickjs/dtoa.c	['fuzz_compile', 'fuzz_eval']	['fuzz_compile', 'fuzz_eval']
/src/quickjs/fuzz/fuzz_common.c	['fuzz_compile', 'fuzz_eval']	['fuzz_compile', 'fuzz_eval']
/src/quickjs/fuzz/fuzz_eval.c	['fuzz_eval']	['fuzz_eval']
/src/quickjs/cutils.c	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']
/src/quickjs/libunicode.c	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']	['fuzz_regexp', 'fuzz_compile', 'fuzz_eval']

Directories in report

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