1 //===-- llvm-rtdyld.cpp - MCJIT Testing Tool ------------------------------===//
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 is a testing tool for use with the MC-JIT LLVM components.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/ADT/StringMap.h"
15 #include "llvm/ADT/OwningPtr.h"
16 #include "llvm/ExecutionEngine/RuntimeDyld.h"
17 #include "llvm/Object/MachOObject.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Support/ManagedStatic.h"
20 #include "llvm/Support/Memory.h"
21 #include "llvm/Support/MemoryBuffer.h"
22 #include "llvm/Support/raw_ostream.h"
23 #include "llvm/Support/system_error.h"
24 using namespace llvm;
25 using namespace llvm::object;
26
27 static cl::list<std::string>
28 InputFileList(cl::Positional, cl::ZeroOrMore,
29 cl::desc("<input file>"));
30
31 enum ActionType {
32 AC_Execute
33 };
34
35 static cl::opt<ActionType>
36 Action(cl::desc("Action to perform:"),
37 cl::init(AC_Execute),
38 cl::values(clEnumValN(AC_Execute, "execute",
39 "Load, link, and execute the inputs."),
40 clEnumValEnd));
41
42 static cl::opt<std::string>
43 EntryPoint("entry",
44 cl::desc("Function to call as entry point."),
45 cl::init("_main"));
46
47 /* *** */
48
49 // A trivial memory manager that doesn't do anything fancy, just uses the
50 // support library allocation routines directly.
51 class TrivialMemoryManager : public RTDyldMemoryManager {
52 public:
53 SmallVector<sys::MemoryBlock, 16> FunctionMemory;
54
55 uint8_t *startFunctionBody(const char *Name, uintptr_t &Size);
56 void endFunctionBody(const char *Name, uint8_t *FunctionStart,
57 uint8_t *FunctionEnd);
58 };
59
startFunctionBody(const char * Name,uintptr_t & Size)60 uint8_t *TrivialMemoryManager::startFunctionBody(const char *Name,
61 uintptr_t &Size) {
62 return (uint8_t*)sys::Memory::AllocateRWX(Size, 0, 0).base();
63 }
64
endFunctionBody(const char * Name,uint8_t * FunctionStart,uint8_t * FunctionEnd)65 void TrivialMemoryManager::endFunctionBody(const char *Name,
66 uint8_t *FunctionStart,
67 uint8_t *FunctionEnd) {
68 uintptr_t Size = FunctionEnd - FunctionStart + 1;
69 FunctionMemory.push_back(sys::MemoryBlock(FunctionStart, Size));
70 }
71
72 static const char *ProgramName;
73
Message(const char * Type,const Twine & Msg)74 static void Message(const char *Type, const Twine &Msg) {
75 errs() << ProgramName << ": " << Type << ": " << Msg << "\n";
76 }
77
Error(const Twine & Msg)78 static int Error(const Twine &Msg) {
79 Message("error", Msg);
80 return 1;
81 }
82
83 /* *** */
84
executeInput()85 static int executeInput() {
86 // Instantiate a dynamic linker.
87 TrivialMemoryManager *MemMgr = new TrivialMemoryManager;
88 RuntimeDyld Dyld(MemMgr);
89
90 // If we don't have any input files, read from stdin.
91 if (!InputFileList.size())
92 InputFileList.push_back("-");
93 for(unsigned i = 0, e = InputFileList.size(); i != e; ++i) {
94 // Load the input memory buffer.
95 OwningPtr<MemoryBuffer> InputBuffer;
96 if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFileList[i],
97 InputBuffer))
98 return Error("unable to read input: '" + ec.message() + "'");
99
100 // Load the object file into it.
101 if (Dyld.loadObject(InputBuffer.take())) {
102 return Error(Dyld.getErrorString());
103 }
104 }
105
106 // Resolve all the relocations we can.
107 Dyld.resolveRelocations();
108
109 // FIXME: Error out if there are unresolved relocations.
110
111 // Get the address of the entry point (_main by default).
112 void *MainAddress = Dyld.getSymbolAddress(EntryPoint);
113 if (MainAddress == 0)
114 return Error("no definition for '" + EntryPoint + "'");
115
116 // Invalidate the instruction cache for each loaded function.
117 for (unsigned i = 0, e = MemMgr->FunctionMemory.size(); i != e; ++i) {
118 sys::MemoryBlock &Data = MemMgr->FunctionMemory[i];
119 // Make sure the memory is executable.
120 std::string ErrorStr;
121 sys::Memory::InvalidateInstructionCache(Data.base(), Data.size());
122 if (!sys::Memory::setExecutable(Data, &ErrorStr))
123 return Error("unable to mark function executable: '" + ErrorStr + "'");
124 }
125
126 // Dispatch to _main().
127 errs() << "loaded '" << EntryPoint << "' at: " << (void*)MainAddress << "\n";
128
129 int (*Main)(int, const char**) =
130 (int(*)(int,const char**)) uintptr_t(MainAddress);
131 const char **Argv = new const char*[2];
132 // Use the name of the first input object module as argv[0] for the target.
133 Argv[0] = InputFileList[0].c_str();
134 Argv[1] = 0;
135 return Main(1, Argv);
136 }
137
main(int argc,char ** argv)138 int main(int argc, char **argv) {
139 ProgramName = argv[0];
140 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
141
142 cl::ParseCommandLineOptions(argc, argv, "llvm MC-JIT tool\n");
143
144 switch (Action) {
145 default:
146 case AC_Execute:
147 return executeInput();
148 }
149
150 return 0;
151 }
152