1 //===-- llvm-strings.cpp - Printable String dumping utility ---------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This program is a utility that works like binutils "strings", that is, it
11 // prints out printable strings in a binary, objdump, or archive file.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/Object/Binary.h"
16 #include "llvm/Support/CommandLine.h"
17 #include "llvm/Support/Error.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/MemoryBuffer.h"
20 #include "llvm/Support/PrettyStackTrace.h"
21 #include "llvm/Support/Program.h"
22 #include "llvm/Support/Signals.h"
23 #include <cctype>
24 #include <string>
25 
26 using namespace llvm;
27 using namespace llvm::object;
28 
29 static cl::list<std::string> InputFileNames(cl::Positional,
30                                             cl::desc("<input object files>"),
31                                             cl::ZeroOrMore);
32 
33 static cl::opt<bool>
34     PrintFileName("print-file-name",
35                   cl::desc("Print the name of the file before each string"));
36 static cl::alias PrintFileNameShort("f", cl::desc(""),
37                                     cl::aliasopt(PrintFileName));
38 
39 static cl::opt<int>
40     MinLength("bytes", cl::desc("Print sequences of the specified length"),
41               cl::init(4));
42 static cl::alias MinLengthShort("n", cl::desc(""), cl::aliasopt(MinLength));
43 
44 static cl::opt<bool>
45     AllSections("all",
46                   cl::desc("Check all sections, not just the data section"));
47 static cl::alias AllSectionsShort("a", cl::desc(""),
48                                     cl::aliasopt(AllSections));
49 
50 enum radix { none, octal, hexadecimal, decimal };
51 static cl::opt<radix>
52     Radix("radix", cl::desc("print the offset within the file"),
53           cl::values(clEnumValN(octal, "o", "octal"),
54                      clEnumValN(hexadecimal, "x", "hexadecimal"),
55                      clEnumValN(decimal, "d", "decimal")),
56           cl::init(none));
57 static cl::alias RadixShort("t", cl::desc(""), cl::aliasopt(Radix));
58 
59 static void strings(raw_ostream &OS, StringRef FileName, StringRef Contents) {
60   auto print = [&OS, FileName](unsigned Offset, StringRef L) {
61     if (L.size() < static_cast<size_t>(MinLength))
62       return;
63     if (PrintFileName)
64       OS << FileName << ":";
65     switch (Radix) {
66     case none:
67       break;
68     case octal:
69       OS << format("%8o", Offset);
70       break;
71     case hexadecimal:
72       OS << format("%8x", Offset);
73       break;
74     case decimal:
75       OS << format("%8u", Offset);
76       break;
77     }
78     OS << " " << L << '\n';
79   };
80 
81   const char *B = Contents.begin();
82   const char *P = nullptr, *E = nullptr, *S = nullptr;
83   for (P = Contents.begin(), E = Contents.end(); P < E; ++P) {
84     if (std::isgraph(*P) || std::isblank(*P)) {
85       if (S == nullptr)
86         S = P;
87     } else if (S) {
88       print(S - B, StringRef(S, P - S));
89       S = nullptr;
90     }
91   }
92   if (S)
93     print(S - B, StringRef(S, E - S));
94 }
95 
96 int main(int argc, char **argv) {
97   sys::PrintStackTraceOnErrorSignal(argv[0]);
98   PrettyStackTraceProgram X(argc, argv);
99 
100   cl::ParseCommandLineOptions(argc, argv, "llvm string dumper\n");
101   if (MinLength == 0) {
102     errs() << "invalid minimum string length 0\n";
103     return EXIT_FAILURE;
104   }
105 
106   if (InputFileNames.empty())
107     InputFileNames.push_back("-");
108 
109   for (const auto &File : InputFileNames) {
110     ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
111         MemoryBuffer::getFileOrSTDIN(File);
112     if (std::error_code EC = Buffer.getError())
113       errs() << File << ": " << EC.message() << '\n';
114     else
115       strings(llvm::outs(), File == "-" ? "{standard input}" : File,
116               Buffer.get()->getMemBufferRef().getBuffer());
117   }
118 
119   return EXIT_SUCCESS;
120 }
121