+/// CheckInvariants - For testing only. Return "" if all internal invariants
+/// are preserved, and a helpful error message otherwise. For free and
+/// allocated blocks, make sure that adding BlockSize gives a valid block.
+/// For free blocks, make sure they're in the free list and that their end of
+/// block size marker is correct. This function should return an error before
+/// accessing bad memory. This function is defined here instead of in
+/// JITMemoryManagerTest.cpp so that we don't have to expose all of the
+/// implementation details of DefaultJITMemoryManager.
+bool DefaultJITMemoryManager::CheckInvariants(std::string &ErrorStr) {
+ raw_string_ostream Err(ErrorStr);
+
+ // Construct a the set of FreeRangeHeader pointers so we can query it
+ // efficiently.
+ llvm::SmallPtrSet<MemoryRangeHeader*, 16> FreeHdrSet;
+ FreeRangeHeader* FreeHead = FreeMemoryList;
+ FreeRangeHeader* FreeRange = FreeHead;
+
+ do {
+ // Check that the free range pointer is in the blocks we've allocated.
+ bool Found = false;
+ for (std::vector<sys::MemoryBlock>::iterator I = CodeSlabs.begin(),
+ E = CodeSlabs.end(); I != E && !Found; ++I) {
+ char *Start = (char*)I->base();
+ char *End = Start + I->size();
+ Found = (Start <= (char*)FreeRange && (char*)FreeRange < End);
+ }
+ if (!Found) {
+ Err << "Corrupt free list; points to " << FreeRange;
+ return false;
+ }
+
+ if (FreeRange->Next->Prev != FreeRange) {
+ Err << "Next and Prev pointers do not match.";
+ return false;
+ }
+
+ // Otherwise, add it to the set.
+ FreeHdrSet.insert(FreeRange);
+ FreeRange = FreeRange->Next;
+ } while (FreeRange != FreeHead);
+
+ // Go over each block, and look at each MemoryRangeHeader.
+ for (std::vector<sys::MemoryBlock>::iterator I = CodeSlabs.begin(),
+ E = CodeSlabs.end(); I != E; ++I) {
+ char *Start = (char*)I->base();
+ char *End = Start + I->size();
+
+ // Check each memory range.
+ for (MemoryRangeHeader *Hdr = (MemoryRangeHeader*)Start, *LastHdr = NULL;
+ Start <= (char*)Hdr && (char*)Hdr < End;
+ Hdr = &Hdr->getBlockAfter()) {
+ if (Hdr->ThisAllocated == 0) {
+ // Check that this range is in the free list.
+ if (!FreeHdrSet.count(Hdr)) {
+ Err << "Found free header at " << Hdr << " that is not in free list.";
+ return false;
+ }
+
+ // Now make sure the size marker at the end of the block is correct.
+ uintptr_t *Marker = ((uintptr_t*)&Hdr->getBlockAfter()) - 1;
+ if (!(Start <= (char*)Marker && (char*)Marker < End)) {
+ Err << "Block size in header points out of current MemoryBlock.";
+ return false;
+ }
+ if (Hdr->BlockSize != *Marker) {
+ Err << "End of block size marker (" << *Marker << ") "
+ << "and BlockSize (" << Hdr->BlockSize << ") don't match.";
+ return false;
+ }
+ }
+
+ if (LastHdr && LastHdr->ThisAllocated != Hdr->PrevAllocated) {
+ Err << "Hdr->PrevAllocated (" << Hdr->PrevAllocated << ") != "
+ << "LastHdr->ThisAllocated (" << LastHdr->ThisAllocated << ")";
+ return false;
+ } else if (!LastHdr && !Hdr->PrevAllocated) {
+ Err << "The first header should have PrevAllocated true.";
+ return false;
+ }
+
+ // Remember the last header.
+ LastHdr = Hdr;
+ }
+ }
+
+ // All invariants are preserved.
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
+// getPointerToNamedFunction() implementation.
+//===----------------------------------------------------------------------===//
+
+// AtExitHandlers - List of functions to call when the program exits,
+// registered with the atexit() library function.
+static std::vector<void (*)()> AtExitHandlers;
+
+/// runAtExitHandlers - Run any functions registered by the program's
+/// calls to atexit(3), which we intercept and store in
+/// AtExitHandlers.
+///
+static void runAtExitHandlers() {
+ while (!AtExitHandlers.empty()) {
+ void (*Fn)() = AtExitHandlers.back();
+ AtExitHandlers.pop_back();
+ Fn();
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Function stubs that are invoked instead of certain library calls
+//
+// Force the following functions to be linked in to anything that uses the
+// JIT. This is a hack designed to work around the all-too-clever Glibc
+// strategy of making these functions work differently when inlined vs. when
+// not inlined, and hiding their real definitions in a separate archive file
+// that the dynamic linker can't see. For more info, search for
+// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+#if defined(__linux__) && defined(__GLIBC__)
+/* stat functions are redirecting to __xstat with a version number. On x86-64
+ * linking with libc_nonshared.a and -Wl,--export-dynamic doesn't make 'stat'
+ * available as an exported symbol, so we have to add it explicitly.
+ */
+namespace {
+class StatSymbols {
+public:
+ StatSymbols() {
+ sys::DynamicLibrary::AddSymbol("stat", (void*)(intptr_t)stat);
+ sys::DynamicLibrary::AddSymbol("fstat", (void*)(intptr_t)fstat);
+ sys::DynamicLibrary::AddSymbol("lstat", (void*)(intptr_t)lstat);
+ sys::DynamicLibrary::AddSymbol("stat64", (void*)(intptr_t)stat64);
+ sys::DynamicLibrary::AddSymbol("\x1stat64", (void*)(intptr_t)stat64);
+ sys::DynamicLibrary::AddSymbol("\x1open64", (void*)(intptr_t)open64);
+ sys::DynamicLibrary::AddSymbol("\x1lseek64", (void*)(intptr_t)lseek64);
+ sys::DynamicLibrary::AddSymbol("fstat64", (void*)(intptr_t)fstat64);
+ sys::DynamicLibrary::AddSymbol("lstat64", (void*)(intptr_t)lstat64);
+ sys::DynamicLibrary::AddSymbol("atexit", (void*)(intptr_t)atexit);
+ sys::DynamicLibrary::AddSymbol("mknod", (void*)(intptr_t)mknod);
+ }
+};
+}
+static StatSymbols initStatSymbols;
+#endif // __linux__
+
+// jit_exit - Used to intercept the "exit" library call.
+static void jit_exit(int Status) {
+ runAtExitHandlers(); // Run atexit handlers...
+ exit(Status);
+}
+
+// jit_atexit - Used to intercept the "atexit" library call.
+static int jit_atexit(void (*Fn)()) {
+ AtExitHandlers.push_back(Fn); // Take note of atexit handler...
+ return 0; // Always successful
+}
+
+static int jit_noop() {
+ return 0;
+}
+
+//===----------------------------------------------------------------------===//
+//
+/// getPointerToNamedFunction - This method returns the address of the specified
+/// function by using the dynamic loader interface. As such it is only useful
+/// for resolving library symbols, not code generated symbols.
+///
+void *DefaultJITMemoryManager::getPointerToNamedFunction(const std::string &Name,
+ bool AbortOnFailure) {
+ // Check to see if this is one of the functions we want to intercept. Note,
+ // we cast to intptr_t here to silence a -pedantic warning that complains
+ // about casting a function pointer to a normal pointer.
+ if (Name == "exit") return (void*)(intptr_t)&jit_exit;
+ if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
+
+ // We should not invoke parent's ctors/dtors from generated main()!
+ // On Mingw and Cygwin, the symbol __main is resolved to
+ // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
+ // (and register wrong callee's dtors with atexit(3)).
+ // We expect ExecutionEngine::runStaticConstructorsDestructors()
+ // is called before ExecutionEngine::runFunctionAsMain() is called.
+ if (Name == "__main") return (void*)(intptr_t)&jit_noop;
+
+ const char *NameStr = Name.c_str();
+ // If this is an asm specifier, skip the sentinal.
+ if (NameStr[0] == 1) ++NameStr;
+
+ // If it's an external function, look it up in the process image...
+ void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+ if (Ptr) return Ptr;
+
+ // If it wasn't found and if it starts with an underscore ('_') character,
+ // try again without the underscore.
+ if (NameStr[0] == '_') {
+ Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+ if (Ptr) return Ptr;
+ }
+
+ // Darwin/PPC adds $LDBLStub suffixes to various symbols like printf. These
+ // are references to hidden visibility symbols that dlsym cannot resolve.
+ // If we have one of these, strip off $LDBLStub and try again.
+#if defined(__APPLE__) && defined(__ppc__)
+ if (Name.size() > 9 && Name[Name.size()-9] == '$' &&
+ memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) {
+ // First try turning $LDBLStub into $LDBL128. If that fails, strip it off.
+ // This mirrors logic in libSystemStubs.a.
+ std::string Prefix = std::string(Name.begin(), Name.end()-9);
+ if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128", false))
+ return Ptr;
+ if (void *Ptr = getPointerToNamedFunction(Prefix, false))
+ return Ptr;
+ }
+#endif
+
+ if (AbortOnFailure) {
+ report_fatal_error("Program used external function '"+Name+
+ "' which could not be resolved!");
+ }
+ return 0;
+}
+
+