xref: /aosp_15_r20/external/harfbuzz_ng/test/fuzzing/hb-subset-fuzzer.cc (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1 #include "hb-fuzzer.hh"
2 
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <string.h>
6 #include <assert.h>
7 
8 #include "hb-subset.h"
9 
10 static void
trySubset(hb_face_t * face,const hb_codepoint_t text[],int text_length,unsigned flag_bits,hb_subset_input_t * input)11 trySubset (hb_face_t *face,
12 	   const hb_codepoint_t text[],
13 	   int text_length,
14            unsigned flag_bits,
15            hb_subset_input_t *input)
16 {
17   if (!input) return;
18 
19   hb_subset_input_set_flags (input, (hb_subset_flags_t) flag_bits);
20 
21   hb_set_t *codepoints = hb_subset_input_unicode_set (input);
22 
23   for (int i = 0; i < text_length; i++)
24     hb_set_add (codepoints, text[i]);
25 
26   hb_face_t *result = hb_subset_or_fail (face, input);
27   if (result)
28   {
29     hb_blob_t *blob = hb_face_reference_blob (result);
30     unsigned int length;
31     const char *data = hb_blob_get_data (blob, &length);
32 
33     // Something not optimizable just to access all the blob data
34     unsigned int bytes_count = 0;
35     for (unsigned int i = 0; i < length; ++i)
36       if (data[i]) ++bytes_count;
37     assert (bytes_count || !length);
38 
39     hb_blob_destroy (blob);
40   }
41   hb_face_destroy (result);
42 
43   hb_subset_input_destroy (input);
44 }
45 
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)46 extern "C" int LLVMFuzzerTestOneInput (const uint8_t *data, size_t size)
47 {
48   alloc_state = _fuzzing_alloc_state (data, size);
49 
50   hb_blob_t *blob = hb_blob_create ((const char *) data, size,
51 				    HB_MEMORY_MODE_READONLY, nullptr, nullptr);
52   hb_face_t *face = hb_face_create (blob, 0);
53 
54   /* Just test this API here quickly. */
55   hb_set_t *output = hb_set_create ();
56   hb_face_collect_unicodes (face, output);
57   hb_set_destroy (output);
58 
59   unsigned flags = HB_SUBSET_FLAGS_DEFAULT;
60   const hb_codepoint_t text[] =
61       {
62 	'A', 'B', 'C', 'D', 'E', 'X', 'Y', 'Z', '1', '2',
63 	'3', '@', '_', '%', '&', ')', '*', '$', '!'
64       };
65 
66   hb_subset_input_t *input = hb_subset_input_create_or_fail ();
67   if (!input)
68   {
69     hb_face_destroy (face);
70     hb_blob_destroy (blob);
71     return 0;
72   }
73   trySubset (face, text, sizeof (text) / sizeof (hb_codepoint_t), flags, input);
74 
75   unsigned num_axes;
76   hb_codepoint_t text_from_data[16];
77   if (size > sizeof (text_from_data) + sizeof (flags) + sizeof(num_axes)) {
78     hb_subset_input_t *input = hb_subset_input_create_or_fail ();
79     if (!input)
80     {
81       hb_face_destroy (face);
82       hb_blob_destroy (blob);
83       return 0;
84     }
85     size -= sizeof (text_from_data);
86     memcpy (text_from_data,
87 	    data + size,
88 	    sizeof (text_from_data));
89 
90     size -= sizeof (flags);
91     memcpy (&flags,
92 	    data + size,
93 	    sizeof (flags));
94 
95     size -= sizeof (num_axes);
96     memcpy (&num_axes,
97 	    data + size,
98 	    sizeof (num_axes));
99 
100     if (num_axes > 0 && num_axes < 8 && size > num_axes * (sizeof(hb_tag_t) + sizeof(int)))
101     {
102       for (unsigned i = 0; i < num_axes; i++) {
103         hb_tag_t tag;
104         int value;
105         size -= sizeof (tag);
106         memcpy (&tag,
107                 data + size,
108                 sizeof (tag));
109         size -= sizeof (value);
110         memcpy (&value,
111                 data + size,
112                 sizeof (value));
113 
114         hb_subset_input_pin_axis_location(input,
115                                           face,
116                                           tag,
117                                           (float) value);
118       }
119     }
120 
121 
122 
123     unsigned int text_size = sizeof (text_from_data) / sizeof (hb_codepoint_t);
124     trySubset (face, text_from_data, text_size, flags, input);
125   }
126 
127   hb_face_destroy (face);
128   hb_blob_destroy (blob);
129 
130   return 0;
131 }
132