1 // Copyright 2020, VIXL authors
2 // All rights reserved.
3 //
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5 // modification, are permitted provided that the following conditions are met:
6 //
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8 // this list of conditions and the following disclaimer.
9 // * Redistributions in binary form must reproduce the above copyright notice,
10 // this list of conditions and the following disclaimer in the documentation
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15 //
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25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27 #include <stdint.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 #include "code-buffer-vixl.h"
33 #include "aarch64/decoder-aarch64.h"
34 #include "aarch64/disasm-aarch64.h"
35
36 // This example is interactive, and isn't tested systematically.
37 #ifndef TEST_EXAMPLES
38
39 using namespace vixl;
40 using namespace vixl::aarch64;
41
PrintUsage(char const * name)42 void PrintUsage(char const* name) {
43 printf("Usage: %s [OPTION]... <INSTRUCTION>...\n", name);
44 printf("\n");
45 printf("Disassemble ad-hoc A64 instructions.\n");
46 printf("\n");
47 printf(
48 "Options:\n"
49 " --start-at <address>\n"
50 " Start disassembling from <address> Any signed 64-bit value\n"
51 " accepted by strtoll can be specified. The address is printed\n"
52 " alongside each instruction, and it is also used to decode\n"
53 " PC-relative offsets.\n"
54 "\n"
55 " Defaults to 0.\n"
56 "\n");
57 printf(
58 "<instruction>\n"
59 " A hexadecimal representation of an A64 instruction. The leading '0x'\n"
60 " (or '0X') is optional.\n"
61 "\n"
62 " Multiple instructions can be provided; they will be disassembled as\n"
63 " if they were read sequentially from memory.\n"
64 "\n");
65 printf("Examples:\n");
66 printf(" $ %s d2824685\n", name);
67 printf(" 0x0000000000000000: d2824685 movz x5, #0x1234\n");
68 printf("\n");
69 printf(" $ %s --start-at -4 0x10fffe85 0xd61f00a0\n", name);
70 printf(" -0x0000000000000004: 10fffe85 adr x5, #-0x30 (addr -0x34)\n");
71 printf(" 0x0000000000000000: d61f00a0 br x5\n");
72 }
73
ParseInstr(char const * arg)74 Instr ParseInstr(char const* arg) {
75 // TODO: Error handling for out-of-range inputs.
76 return (Instr)strtoul(arg, NULL, 16);
77 }
78
ParseInt64(char const * arg)79 int64_t ParseInt64(char const* arg) {
80 // TODO: Error handling for out-of-range inputs.
81 return (int64_t)strtoll(arg, NULL, 0);
82 }
83
main(int argc,char * argv[])84 int main(int argc, char* argv[]) {
85 for (int i = 1; i < argc; i++) {
86 char const* arg = argv[i];
87 if ((strcmp(arg, "--help") == 0) || (strcmp(arg, "-h") == 0)) {
88 PrintUsage(argv[0]);
89 return 0;
90 }
91 }
92
93 // Assume an address of 0, unless otherwise specified.
94 int64_t start_address = 0;
95 // Allocate space for one instruction per argument.
96 CodeBuffer buffer((argc - 1) * kInstructionSize);
97
98 bool expect_start_at = false;
99 for (int i = 1; i < argc; i++) {
100 char* arg = argv[i];
101 if (expect_start_at) {
102 start_address = ParseInt64(arg);
103 expect_start_at = false;
104 } else if (strcmp(arg, "--start-at") == 0) {
105 expect_start_at = true;
106 } else {
107 // Assume that everything else is an instruction.
108 buffer.Emit(ParseInstr(arg));
109 }
110 }
111 buffer.SetClean();
112
113 if (expect_start_at) {
114 printf("No address given. Use: --start-at <address>\n");
115 return 1;
116 }
117
118 if (buffer.GetSizeInBytes() == 0) {
119 printf("Nothing to disassemble.\n");
120 return 0;
121 }
122
123 // Disassemble the buffer.
124 const Instruction* start = buffer.GetStartAddress<Instruction*>();
125 const Instruction* end = buffer.GetEndAddress<Instruction*>();
126 vixl::aarch64::PrintDisassembler disasm(stdout);
127 disasm.PrintSignedAddresses(true);
128 disasm.MapCodeAddress(start_address, start);
129 disasm.DisassembleBuffer(start, end);
130
131 return 0;
132 }
133
134 #endif // TEST_EXAMPLES
135