LLVM  9.0.0svn
RTDyldMemoryManager.cpp
Go to the documentation of this file.
1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Implementation of the runtime dynamic memory manager base class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Config/config.h"
15 #include "llvm/Support/Compiler.h"
18 #include <cstdlib>
19 
20 #ifdef __linux__
21  // These includes used by RTDyldMemoryManager::getPointerToNamedFunction()
22  // for Glibc trickery. See comments in this function for more information.
23  #ifdef HAVE_SYS_STAT_H
24  #include <sys/stat.h>
25  #endif
26  #include <fcntl.h>
27  #include <unistd.h>
28 #endif
29 
30 namespace llvm {
31 
33 
34 // Determine whether we can register EH tables.
35 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \
36  !(defined(_AIX) && defined(__ibmxl__)) && !defined(__SEH__) && \
37  !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.
51 static 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 =
59  }
60  if (rf)
61  rf(p);
62 }
63 
64 static void __deregister_frame(void *p) {
65  static bool Searched = false;
66  static void((*df)(void *)) = 0;
67 
68  if (!Searched) {
69  Searched = true;
71  "__deregister_frame");
72  }
73  if (df)
74  df(p);
75 }
76 #endif
77 
78 #ifdef __APPLE__
79 
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.
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/061737.html
101  // and projects/libunwind/src/UnwindLevel1-gcc-ext.c.
102  const char *P = (const char *)Addr;
103  const char *End = P + Size;
104  do {
105  P = processFDE(P, false);
106  } while(P != End);
107 }
108 
110  size_t Size) {
111  const char *P = (const char *)Addr;
112  const char *End = P + Size;
113  do {
114  P = processFDE(P, true);
115  } while(P != End);
116 }
117 
118 #else
119 
121  size_t Size) {
122  // On Linux __register_frame takes a single argument:
123  // a pointer to the start of the .eh_frame section.
124 
125  // How can it find the end? Because crtendS.o is linked
126  // in and it has an .eh_frame section with four zero chars.
127  __register_frame(Addr);
128 }
129 
131  size_t Size) {
132  __deregister_frame(Addr);
133 }
134 
135 #endif
136 
137 void RTDyldMemoryManager::registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
138  size_t Size) {
139  registerEHFramesInProcess(Addr, Size);
140  EHFrames.push_back({Addr, Size});
141 }
142 
144  for (auto &Frame : EHFrames)
145  deregisterEHFramesInProcess(Frame.Addr, Frame.Size);
146  EHFrames.clear();
147 }
148 
149 static int jit_noop() {
150  return 0;
151 }
152 
153 // ARM math functions are statically linked on Android from libgcc.a, but not
154 // available at runtime for dynamic linking. On Linux these are usually placed
155 // in libgcc_s.so so can be found by normal dynamic lookup.
156 #if defined(__BIONIC__) && defined(__arm__)
157 // List of functions which are statically linked on Android and can be generated
158 // by LLVM. This is done as a nested macro which is used once to declare the
159 // imported functions with ARM_MATH_DECL and once to compare them to the
160 // user-requested symbol in getSymbolAddress with ARM_MATH_CHECK. The test
161 // assumes that all functions start with __aeabi_ and getSymbolAddress must be
162 // modified if that changes.
163 #define ARM_MATH_IMPORTS(PP) \
164  PP(__aeabi_d2f) \
165  PP(__aeabi_d2iz) \
166  PP(__aeabi_d2lz) \
167  PP(__aeabi_d2uiz) \
168  PP(__aeabi_d2ulz) \
169  PP(__aeabi_dadd) \
170  PP(__aeabi_dcmpeq) \
171  PP(__aeabi_dcmpge) \
172  PP(__aeabi_dcmpgt) \
173  PP(__aeabi_dcmple) \
174  PP(__aeabi_dcmplt) \
175  PP(__aeabi_dcmpun) \
176  PP(__aeabi_ddiv) \
177  PP(__aeabi_dmul) \
178  PP(__aeabi_dsub) \
179  PP(__aeabi_f2d) \
180  PP(__aeabi_f2iz) \
181  PP(__aeabi_f2lz) \
182  PP(__aeabi_f2uiz) \
183  PP(__aeabi_f2ulz) \
184  PP(__aeabi_fadd) \
185  PP(__aeabi_fcmpeq) \
186  PP(__aeabi_fcmpge) \
187  PP(__aeabi_fcmpgt) \
188  PP(__aeabi_fcmple) \
189  PP(__aeabi_fcmplt) \
190  PP(__aeabi_fcmpun) \
191  PP(__aeabi_fdiv) \
192  PP(__aeabi_fmul) \
193  PP(__aeabi_fsub) \
194  PP(__aeabi_i2d) \
195  PP(__aeabi_i2f) \
196  PP(__aeabi_idiv) \
197  PP(__aeabi_idivmod) \
198  PP(__aeabi_l2d) \
199  PP(__aeabi_l2f) \
200  PP(__aeabi_lasr) \
201  PP(__aeabi_ldivmod) \
202  PP(__aeabi_llsl) \
203  PP(__aeabi_llsr) \
204  PP(__aeabi_lmul) \
205  PP(__aeabi_ui2d) \
206  PP(__aeabi_ui2f) \
207  PP(__aeabi_uidiv) \
208  PP(__aeabi_uidivmod) \
209  PP(__aeabi_ul2d) \
210  PP(__aeabi_ul2f) \
211  PP(__aeabi_uldivmod)
212 
213 // Declare statically linked math functions on ARM. The function declarations
214 // here do not have the correct prototypes for each function in
215 // ARM_MATH_IMPORTS, but it doesn't matter because only the symbol addresses are
216 // needed. In particular the __aeabi_*divmod functions do not have calling
217 // conventions which match any C prototype.
218 #define ARM_MATH_DECL(name) extern "C" void name();
219 ARM_MATH_IMPORTS(ARM_MATH_DECL)
220 #undef ARM_MATH_DECL
221 #endif
222 
223 #if defined(__linux__) && defined(__GLIBC__) && \
224  (defined(__i386__) || defined(__x86_64__))
225 extern "C" LLVM_ATTRIBUTE_WEAK void __morestack();
226 #endif
227 
228 uint64_t
230  // This implementation assumes that the host program is the target.
231  // Clients generating code for a remote target should implement their own
232  // memory manager.
233 #if defined(__linux__) && defined(__GLIBC__)
234  //===--------------------------------------------------------------------===//
235  // Function stubs that are invoked instead of certain library calls
236  //
237  // Force the following functions to be linked in to anything that uses the
238  // JIT. This is a hack designed to work around the all-too-clever Glibc
239  // strategy of making these functions work differently when inlined vs. when
240  // not inlined, and hiding their real definitions in a separate archive file
241  // that the dynamic linker can't see. For more info, search for
242  // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
243  if (Name == "stat") return (uint64_t)&stat;
244  if (Name == "fstat") return (uint64_t)&fstat;
245  if (Name == "lstat") return (uint64_t)&lstat;
246  if (Name == "stat64") return (uint64_t)&stat64;
247  if (Name == "fstat64") return (uint64_t)&fstat64;
248  if (Name == "lstat64") return (uint64_t)&lstat64;
249  if (Name == "atexit") return (uint64_t)&atexit;
250  if (Name == "mknod") return (uint64_t)&mknod;
251 
252 #if defined(__i386__) || defined(__x86_64__)
253  // __morestack lives in libgcc, a static library.
254  if (&__morestack && Name == "__morestack")
255  return (uint64_t)&__morestack;
256 #endif
257 #endif // __linux__ && __GLIBC__
258 
259  // See ARM_MATH_IMPORTS definition for explanation
260 #if defined(__BIONIC__) && defined(__arm__)
261  if (Name.compare(0, 8, "__aeabi_") == 0) {
262  // Check if the user has requested any of the functions listed in
263  // ARM_MATH_IMPORTS, and if so redirect to the statically linked symbol.
264 #define ARM_MATH_CHECK(fn) if (Name == #fn) return (uint64_t)&fn;
265  ARM_MATH_IMPORTS(ARM_MATH_CHECK)
266 #undef ARM_MATH_CHECK
267  }
268 #endif
269 
270  // We should not invoke parent's ctors/dtors from generated main()!
271  // On Mingw and Cygwin, the symbol __main is resolved to
272  // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
273  // (and register wrong callee's dtors with atexit(3)).
274  // We expect ExecutionEngine::runStaticConstructorsDestructors()
275  // is called before ExecutionEngine::runFunctionAsMain() is called.
276  if (Name == "__main") return (uint64_t)&jit_noop;
277 
278  const char *NameStr = Name.c_str();
279 
280  // DynamicLibrary::SearchForAddresOfSymbol expects an unmangled 'C' symbol
281  // name so ff we're on Darwin, strip the leading '_' off.
282 #ifdef __APPLE__
283  if (NameStr[0] == '_')
284  ++NameStr;
285 #endif
286 
287  return (uint64_t)sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
288 }
289 
291  bool AbortOnFailure) {
292  uint64_t Addr = getSymbolAddress(Name);
293 
294  if (!Addr && AbortOnFailure)
295  report_fatal_error("Program used external function '" + Name +
296  "' which could not be resolved!");
297 
298  return (void*)Addr;
299 }
300 
301 void RTDyldMemoryManager::anchor() {}
302 void MCJITMemoryManager::anchor() {}
303 } // namespace llvm
static void * SearchForAddressOfSymbol(const char *symbolName)
This function will search through all previously loaded dynamic libraries for the symbol symbolName...
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
This class represents lattice values for constants.
Definition: AllocatorList.h:23
static void registerEHFramesInProcess(uint8_t *Addr, size_t Size)
Register EH frames in the current process.
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override
Register the EH frames with the runtime so that c++ exceptions work.
virtual uint64_t getSymbolAddress(const std::string &Name)
Legacy symbol lookup - DEPRECATED! Please override findSymbol instead.
static void __register_frame(void *p)
static void deregisterEHFramesInProcess(uint8_t *Addr, size_t Size)
Deregister EH frames in the current proces.
#define LLVM_ATTRIBUTE_WEAK
Definition: Compiler.h:167
static void __deregister_frame(void *p)
#define P(N)
uint32_t Size
Definition: Profile.cpp:46
virtual void * getPointerToNamedFunction(const std::string &Name, bool AbortOnFailure=true)
This method returns the address of the specified function.
static int jit_noop()
static uint64_t getSymbolAddressInProcess(const std::string &Name)
This method returns the address of the specified function or variable in the current process...