High level conclusions

Fuzzers reach 50.28% of cyclomatic complexity.

Fuzzers reach 55.73% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

991 / 1778

Cyclomatic complexity statically reachable by fuzzers

7366 / 14649

Runtime code coverage of functions

879 / 1778

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]	7	1.18%
yellow	[10:29]	8	1.35%
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	3552	69.2%
gold	[1:9]	369	7.19%
yellow	[10:29]	508	9.90%
greenyellow	[30:49]	166	3.23%
lawngreen	50+	536	10.4%
All colors	5131	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
225	3913	re_string_list_free	call site: 03913	re_parse_class_set_operand
188	2773	JS_CallInternal	call site: 02773	js_binary_logic_slow
181	4767	js_std_add_helpers	call site: 04767	js_print
130	2245	JS_ConcatString3	call site: 02245	JS_DefinePropertyValue
102	3610	JS_AddIntrinsicDate	call site: 03610	js_Date_parse
81	2583	js_binary_arith_slow	call site: 02583	js_bigint_add
69	4387	JS_AddIntrinsicTypedArrays	call site: 04387	js_typed_array_constructor_obj
67	737	round_to_d	call site: 00737	js_new_string8_len
65	4637	ident_realloc	call site: 04637	json_parse_value
56	3030	js_async_function_resume	call site: 03030	js_promise_resolve
53	2181	JS_CallInternal	call site: 02181	JS_NewSymbolFromAtom
49	3199	JS_EvalFunctionInternal	call site: 03199	JS_ThrowTypeError

Runtime coverage analysis

Covered functions

674

Functions that are reachable but not covered

457

Reachable functions

955

Percentage of reachable functions covered

52.15%

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	694
./list.h	6
./cutils.h	27
./quickjs.h	23
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	3416	61.2%
gold	[1:9]	259	4.64%
yellow	[10:29]	522	9.35%
greenyellow	[30:49]	113	2.02%
lawngreen	50+	1267	22.7%
All colors	5577	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
181	4767	js_std_add_helpers	call site: 04767	js_print
173	3913	re_string_list_free	call site: 03913	parse_class_string_disjunction
106	2855	JS_CallInternal	call site: 02855	js_operator_in
102	3610	JS_AddIntrinsicDate	call site: 03610	js_Date_parse
77	3087	js_async_function_call	call site: 03087	JS_NewCFunctionData
72	2098	JS_GetIterator	call site: 02098	JS_GetIterator2
69	4387	JS_AddIntrinsicTypedArrays	call site: 04387	js_typed_array_constructor_obj
65	4637	ident_realloc	call site: 04637	json_parse_value
56	2313	JS_CallInternal	call site: 02313	JS_GetPropertyValue
56	3030	js_async_function_resume	call site: 03030	js_promise_resolve
53	4177	re_parse_term	call site: 04177	re_emit_goto
52	3793	re_parse_term	call site: 03793	re_parse_disjunction

Runtime coverage analysis

Covered functions

801

Functions that are reachable but not covered

418

Reachable functions

1019

Percentage of reachable functions covered

58.98%

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	757
./list.h	6
./cutils.h	28
./quickjs.h	23
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']	96	0	341	58	20	814	0	7305	2685
js_json_stringify	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	74	0	20	3	2	642	0	4793	291
js_regexp_Symbol_replace	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	67	0	777	127	51	647	0	5030	207
js_string_normalize	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	66	0	155	31	13	630	0	4640	126
js_os_exec	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	69	0	743	161	60	629	0	4611	110
js_typed_array_indexOf	/src/quickjs/quickjs.c	6	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'int']	52	0	893	215	88	619	0	4612	105
JS_ComputeMemoryUsage	/src/quickjs/quickjs.c	2	['N/A', 'N/A']	3	0	1042	153	50	6	0	73	67
js_std_file_printf	/src/quickjs/quickjs-libc.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	71	0	29	6	3	622	0	4568	66
js_array_toSorted	/src/quickjs/quickjs.c	5	['N/A', 'size_t', 'size_t', 'int', 'N/A']	71	0	239	43	17	619	0	4579	63
js_object_groupBy	/src/quickjs/quickjs.c	6	['N/A', 'size_t', 'size_t', 'int', 'N/A', 'int']	67	0	339	50	21	629	0	4641	59

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

Functions statically reachable by fuzzers

1257 / 1778

Cyclomatic complexity statically reachable by fuzzers

11121 / 14649

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=['re_string_list_free', 'JS_CallInternal', 'js_std_add_helpers', 'JS_ConcatString3', 'JS_AddIntrinsicDate', 'js_binary_arith_slow', 'JS_AddIntrinsicTypedArrays', 'round_to_d', 'ident_realloc', '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_GetIterator', 'JS_AddIntrinsicTypedArrays', '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	63	45.65%	['fuzz_compile', 'fuzz_eval']
JS_SetPropertyInternal	250	50	20.0%	['fuzz_compile', 'fuzz_eval']
JS_DefineProperty	236	58	24.57%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyNamesInternal	180	96	53.33%	['fuzz_compile', 'fuzz_eval']
JS_GetOwnPropertyInternal	70	29	41.42%	['fuzz_compile', 'fuzz_eval']
JS_GetPropertyValue	66	26	39.39%	['fuzz_compile', 'fuzz_eval']
JS_ToBoolFree	59	25	42.37%	['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	2469	821	33.25%	['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	90	50.56%	['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	41	50.61%	['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_exec	185	97	52.43%	['fuzz_eval']
js_regexp_constructor	73	25	34.24%	['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_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	296	51.12%	['fuzz_compile', 'fuzz_eval']
js_parse_array_literal	84	35	41.66%	['fuzz_eval']
js_parse_assign_expr2	233	42	18.02%	['fuzz_compile', 'fuzz_eval']
js_parse_import	125	29	23.20%	['fuzz_compile', 'fuzz_eval']
js_parse_statement_or_decl	626	280	44.72%	['fuzz_compile', 'fuzz_eval']
emit_return	68	17	25.0%	['fuzz_compile', 'fuzz_eval']
instantiate_hoisted_definitions	111	48	43.24%	['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	30	34.09%	['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_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	395	85	21.51%	['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/libunicode.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/./cutils.h	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/cutils.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', '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/./quickjs.h	['fuzz_eval', 'fuzz_compile']	[]
/src/quickjs/dtoa.c	['fuzz_eval', 'fuzz_compile']	['fuzz_eval', 'fuzz_compile']
/src/quickjs/quickjs.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/fuzz/fuzz_compile.c	['fuzz_compile']	['fuzz_compile']
/src/quickjs/fuzz/fuzz_eval.c	['fuzz_eval']	['fuzz_eval']
/src/quickjs/libregexp.c	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']	['fuzz_regexp', 'fuzz_eval', 'fuzz_compile']

Directories in report

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