1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "hex_dump.h"
18 
19 #include "globals.h"
20 
21 #include <string.h>
22 
23 namespace art {
24 
Dump(std::ostream & os) const25 void HexDump::Dump(std::ostream& os) const {
26   if (byte_count_ == 0) {
27     return;
28   }
29 
30   if (address_ == nullptr) {
31     os << "00000000:";
32     return;
33   }
34 
35   static const char gHexDigit[] = "0123456789abcdef";
36   const unsigned char* addr = reinterpret_cast<const unsigned char*>(address_);
37   // 01234560: 00 11 22 33 44 55 66 77 88 99 aa bb cc dd ee ff  0123456789abcdef
38   char out[(kBitsPerIntPtrT / 4) + /* offset */
39            1 + /* colon */
40            (16 * 3) + /* 16 hex digits and space */
41            2 + /* white space */
42            16 + /* 16 characters*/
43            1 /* \0 */ ];
44   size_t offset;    /* offset to show while printing */
45 
46   if (show_actual_addresses_) {
47     offset = reinterpret_cast<size_t>(addr);
48   } else {
49     offset = 0;
50   }
51   memset(out, ' ', sizeof(out)-1);
52   out[kBitsPerIntPtrT / 4] = ':';
53   out[sizeof(out)-1] = '\0';
54 
55   size_t byte_count = byte_count_;
56   size_t gap = offset & 0x0f;
57   while (byte_count > 0) {
58     size_t line_offset = offset & ~0x0f;
59 
60     char* hex = out;
61     char* asc = out + (kBitsPerIntPtrT / 4) + /* offset */ 1 + /* colon */
62         (16 * 3) + /* 16 hex digits and space */ 2 /* white space */;
63 
64     for (int i = 0; i < (kBitsPerIntPtrT / 4); i++) {
65       *hex++ = gHexDigit[line_offset >> (kBitsPerIntPtrT - 4)];
66       line_offset <<= 4;
67     }
68     hex++;
69     hex++;
70 
71     size_t count = std::min(byte_count, 16 - gap);
72     // CHECK_NE(count, 0U);
73     // CHECK_LE(count + gap, 16U);
74 
75     if (gap) {
76       /* only on first line */
77       hex += gap * 3;
78       asc += gap;
79     }
80 
81     size_t i;
82     for (i = gap ; i < count + gap; i++) {
83       *hex++ = gHexDigit[*addr >> 4];
84       *hex++ = gHexDigit[*addr & 0x0f];
85       hex++;
86       if (*addr >= 0x20 && *addr < 0x7f /*isprint(*addr)*/) {
87         *asc++ = *addr;
88       } else {
89         *asc++ = '.';
90       }
91       addr++;
92     }
93     for (; i < 16; i++) {
94       /* erase extra stuff; only happens on last line */
95       *hex++ = ' ';
96       *hex++ = ' ';
97       hex++;
98       *asc++ = ' ';
99     }
100 
101     os << prefix_ << out;
102 
103     gap = 0;
104     byte_count -= count;
105     offset += count;
106     if (byte_count > 0) {
107       os << "\n";
108     }
109   }
110 }
111 
112 }  // namespace art
113