1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
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 // Implementation of the runtime dynamic memory manager base class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/Config/config.h"
15 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
16 #include "llvm/Support/Compiler.h"
17 #include "llvm/Support/DynamicLibrary.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include <cstdlib>
20
21 #ifdef __linux__
22 // These includes used by RTDyldMemoryManager::getPointerToNamedFunction()
23 // for Glibc trickery. See comments in this function for more information.
24 #ifdef HAVE_SYS_STAT_H
25 #include <sys/stat.h>
26 #endif
27 #include <fcntl.h>
28 #include <unistd.h>
29 #endif
30
31 namespace llvm {
32
~RTDyldMemoryManager()33 RTDyldMemoryManager::~RTDyldMemoryManager() {}
34
35 // Determine whether we can register EH tables.
36 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \
37 !defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__))
38 #define HAVE_EHTABLE_SUPPORT 1
39 #else
40 #define HAVE_EHTABLE_SUPPORT 0
41 #endif
42
43 #if HAVE_EHTABLE_SUPPORT
44 extern "C" void __register_frame(void *);
45 extern "C" void __deregister_frame(void *);
46 #else
47 // The building compiler does not have __(de)register_frame but
48 // it may be found at runtime in a dynamically-loaded library.
49 // For example, this happens when building LLVM with Visual C++
50 // but using the MingW runtime.
__register_frame(void * p)51 void __register_frame(void *p) {
52 static bool Searched = false;
53 static void((*rf)(void *)) = 0;
54
55 if (!Searched) {
56 Searched = true;
57 *(void **)&rf =
58 llvm::sys::DynamicLibrary::SearchForAddressOfSymbol("__register_frame");
59 }
60 if (rf)
61 rf(p);
62 }
63
__deregister_frame(void * p)64 void __deregister_frame(void *p) {
65 static bool Searched = false;
66 static void((*df)(void *)) = 0;
67
68 if (!Searched) {
69 Searched = true;
70 *(void **)&df = llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(
71 "__deregister_frame");
72 }
73 if (df)
74 df(p);
75 }
76 #endif
77
78 #ifdef __APPLE__
79
processFDE(const char * Entry,bool isDeregister)80 static const char *processFDE(const char *Entry, bool isDeregister) {
81 const char *P = Entry;
82 uint32_t Length = *((const uint32_t *)P);
83 P += 4;
84 uint32_t Offset = *((const uint32_t *)P);
85 if (Offset != 0) {
86 if (isDeregister)
87 __deregister_frame(const_cast<char *>(Entry));
88 else
89 __register_frame(const_cast<char *>(Entry));
90 }
91 return P + Length;
92 }
93
94 // This implementation handles frame registration for local targets.
95 // Memory managers for remote targets should re-implement this function
96 // and use the LoadAddr parameter.
registerEHFramesInProcess(uint8_t * Addr,size_t Size)97 void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr,
98 size_t Size) {
99 // On OS X OS X __register_frame takes a single FDE as an argument.
100 // See http://lists.llvm.org/pipermail/llvm-dev/2013-April/061768.html
101 const char *P = (const char *)Addr;
102 const char *End = P + Size;
103 do {
104 P = processFDE(P, false);
105 } while(P != End);
106 }
107
deregisterEHFramesInProcess(uint8_t * Addr,size_t Size)108 void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr,
109 size_t Size) {
110 const char *P = (const char *)Addr;
111 const char *End = P + Size;
112 do {
113 P = processFDE(P, true);
114 } while(P != End);
115 }
116
117 #else
118
registerEHFramesInProcess(uint8_t * Addr,size_t Size)119 void RTDyldMemoryManager::registerEHFramesInProcess(uint8_t *Addr,
120 size_t Size) {
121 // On Linux __register_frame takes a single argument:
122 // a pointer to the start of the .eh_frame section.
123
124 // How can it find the end? Because crtendS.o is linked
125 // in and it has an .eh_frame section with four zero chars.
126 __register_frame(Addr);
127 }
128
deregisterEHFramesInProcess(uint8_t * Addr,size_t Size)129 void RTDyldMemoryManager::deregisterEHFramesInProcess(uint8_t *Addr,
130 size_t Size) {
131 __deregister_frame(Addr);
132 }
133
134 #endif
135
jit_noop()136 static int jit_noop() {
137 return 0;
138 }
139
140 // ARM math functions are statically linked on Android from libgcc.a, but not
141 // available at runtime for dynamic linking. On Linux these are usually placed
142 // in libgcc_s.so so can be found by normal dynamic lookup.
143 #if defined(__BIONIC__) && defined(__arm__)
144 // List of functions which are statically linked on Android and can be generated
145 // by LLVM. This is done as a nested macro which is used once to declare the
146 // imported functions with ARM_MATH_DECL and once to compare them to the
147 // user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test
148 // assumes that all functions start with __aeabi_ and getSymbolAddress must be
149 // modified if that changes.
150 #define ARM_MATH_IMPORTS(PP) \
151 PP(__aeabi_d2f) \
152 PP(__aeabi_d2iz) \
153 PP(__aeabi_d2lz) \
154 PP(__aeabi_d2uiz) \
155 PP(__aeabi_d2ulz) \
156 PP(__aeabi_dadd) \
157 PP(__aeabi_dcmpeq) \
158 PP(__aeabi_dcmpge) \
159 PP(__aeabi_dcmpgt) \
160 PP(__aeabi_dcmple) \
161 PP(__aeabi_dcmplt) \
162 PP(__aeabi_dcmpun) \
163 PP(__aeabi_ddiv) \
164 PP(__aeabi_dmul) \
165 PP(__aeabi_dsub) \
166 PP(__aeabi_f2d) \
167 PP(__aeabi_f2iz) \
168 PP(__aeabi_f2lz) \
169 PP(__aeabi_f2uiz) \
170 PP(__aeabi_f2ulz) \
171 PP(__aeabi_fadd) \
172 PP(__aeabi_fcmpeq) \
173 PP(__aeabi_fcmpge) \
174 PP(__aeabi_fcmpgt) \
175 PP(__aeabi_fcmple) \
176 PP(__aeabi_fcmplt) \
177 PP(__aeabi_fcmpun) \
178 PP(__aeabi_fdiv) \
179 PP(__aeabi_fmul) \
180 PP(__aeabi_fsub) \
181 PP(__aeabi_i2d) \
182 PP(__aeabi_i2f) \
183 PP(__aeabi_idiv) \
184 PP(__aeabi_idivmod) \
185 PP(__aeabi_l2d) \
186 PP(__aeabi_l2f) \
187 PP(__aeabi_lasr) \
188 PP(__aeabi_ldivmod) \
189 PP(__aeabi_llsl) \
190 PP(__aeabi_llsr) \
191 PP(__aeabi_lmul) \
192 PP(__aeabi_ui2d) \
193 PP(__aeabi_ui2f) \
194 PP(__aeabi_uidiv) \
195 PP(__aeabi_uidivmod) \
196 PP(__aeabi_ul2d) \
197 PP(__aeabi_ul2f) \
198 PP(__aeabi_uldivmod)
199
200 // Declare statically linked math functions on ARM. The function declarations
201 // here do not have the correct prototypes for each function in
202 // ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are
203 // needed. In particular the __aeabi_*divmod functions do not have calling
204 // conventions which match any C prototype.
205 #define ARM_MATH_DECL(name) extern "C" void name();
206 ARM_MATH_IMPORTS(ARM_MATH_DECL)
207 #undef ARM_MATH_DECL
208 #endif
209
210 #if defined(__linux__) && defined(__GLIBC__) && \
211 (defined(__i386__) || defined(__x86_64__))
212 extern "C" LLVM_ATTRIBUTE_WEAK void __morestack();
213 #endif
214
215 uint64_t
getSymbolAddressInProcess(const std::string & Name)216 RTDyldMemoryManager::getSymbolAddressInProcess(const std::string &Name) {
217 // This implementation assumes that the host program is the target.
218 // Clients generating code for a remote target should implement their own
219 // memory manager.
220 #if defined(__linux__) && defined(__GLIBC__)
221 //===--------------------------------------------------------------------===//
222 // Function stubs that are invoked instead of certain library calls
223 //
224 // Force the following functions to be linked in to anything that uses the
225 // JIT. This is a hack designed to work around the all-too-clever Glibc
226 // strategy of making these functions work differently when inlined vs. when
227 // not inlined, and hiding their real definitions in a separate archive file
228 // that the dynamic linker can't see. For more info, search for
229 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
230 if (Name == "stat") return (uint64_t)&stat;
231 if (Name == "fstat") return (uint64_t)&fstat;
232 if (Name == "lstat") return (uint64_t)&lstat;
233 if (Name == "stat64") return (uint64_t)&stat64;
234 if (Name == "fstat64") return (uint64_t)&fstat64;
235 if (Name == "lstat64") return (uint64_t)&lstat64;
236 if (Name == "atexit") return (uint64_t)&atexit;
237 if (Name == "mknod") return (uint64_t)&mknod;
238
239 #if defined(__i386__) || defined(__x86_64__)
240 // __morestack lives in libgcc, a static library.
241 if (&__morestack && Name == "__morestack")
242 return (uint64_t)&__morestack;
243 #endif
244 #endif // __linux__ && __GLIBC__
245
246 // See ARM_MATH_IMPORTS definition for explanation
247 #if defined(__BIONIC__) && defined(__arm__)
248 if (Name.compare(0, 8, "__aeabi_") == 0) {
249 // Check if the user has requested any of the functions listed in
250 // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol.
251 #define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn;
252 ARM_MATH_IMPORTS(ARM_MATH_CHECK)
253 #undef ARM_MATH_CHECK
254 }
255 #endif
256
257 // We should not invoke parent's ctors/dtors from generated main()!
258 // On Mingw and Cygwin, the symbol __main is resolved to
259 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
260 // (and register wrong callee's dtors with atexit(3)).
261 // We expect ExecutionEngine::runStaticConstructorsDestructors()
262 // is called before ExecutionEngine::runFunctionAsMain() is called.
263 if (Name == "__main") return (uint64_t)&jit_noop;
264
265 const char *NameStr = Name.c_str();
266
267 // DynamicLibrary::SearchForAddresOfSymbol expects an unmangled 'C' symbol
268 // name so ff we're on Darwin, strip the leading '_' off.
269 #ifdef __APPLE__
270 if (NameStr[0] == '_')
271 ++NameStr;
272 #endif
273
274 return (uint64_t)sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
275 }
276
getPointerToNamedFunction(const std::string & Name,bool AbortOnFailure)277 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,
278 bool AbortOnFailure) {
279 uint64_t Addr = getSymbolAddress(Name);
280
281 if (!Addr && AbortOnFailure)
282 report_fatal_error("Program used external function '" + Name +
283 "' which could not be resolved!");
284
285 return (void*)Addr;
286 }
287
288 } // namespace llvm
289