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Diffstat (limited to 'contrib/llvm/lib/Support/DynamicLibrary.cpp')
-rw-r--r-- | contrib/llvm/lib/Support/DynamicLibrary.cpp | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/DynamicLibrary.cpp b/contrib/llvm/lib/Support/DynamicLibrary.cpp new file mode 100644 index 0000000..455c380 --- /dev/null +++ b/contrib/llvm/lib/Support/DynamicLibrary.cpp @@ -0,0 +1,170 @@ +//===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This header file implements the operating system DynamicLibrary concept. +// +// FIXME: This file leaks the ExplicitSymbols and OpenedHandles vector, and is +// not thread safe! +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/DynamicLibrary.h" +#include "llvm/Support/Mutex.h" +#include "llvm/Config/config.h" +#include <cstdio> +#include <cstring> +#include <map> +#include <vector> + +// Collection of symbol name/value pairs to be searched prior to any libraries. +static std::map<std::string, void*> *ExplicitSymbols = 0; + +namespace { + +struct ExplicitSymbolsDeleter { + ~ExplicitSymbolsDeleter() { + if (ExplicitSymbols) + delete ExplicitSymbols; + } +}; + +} + +static ExplicitSymbolsDeleter Dummy; + +void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName, + void *symbolValue) { + if (ExplicitSymbols == 0) + ExplicitSymbols = new std::map<std::string, void*>(); + (*ExplicitSymbols)[symbolName] = symbolValue; +} + +#ifdef LLVM_ON_WIN32 + +#include "Windows/DynamicLibrary.inc" + +#else + +#if HAVE_DLFCN_H +#include <dlfcn.h> +using namespace llvm; +using namespace llvm::sys; + +//===----------------------------------------------------------------------===// +//=== WARNING: Implementation here must contain only TRULY operating system +//=== independent code. +//===----------------------------------------------------------------------===// + +static std::vector<void *> *OpenedHandles = 0; + + +static SmartMutex<true>& getMutex() { + static SmartMutex<true> HandlesMutex; + return HandlesMutex; +} + + +bool DynamicLibrary::LoadLibraryPermanently(const char *Filename, + std::string *ErrMsg) { + void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL); + if (H == 0) { + if (ErrMsg) *ErrMsg = dlerror(); + return true; + } +#ifdef __CYGWIN__ + // Cygwin searches symbols only in the main + // with the handle of dlopen(NULL, RTLD_GLOBAL). + if (Filename == NULL) + H = RTLD_DEFAULT; +#endif + SmartScopedLock<true> Lock(getMutex()); + if (OpenedHandles == 0) + OpenedHandles = new std::vector<void *>(); + OpenedHandles->push_back(H); + return false; +} +#else + +using namespace llvm; +using namespace llvm::sys; + +bool DynamicLibrary::LoadLibraryPermanently(const char *Filename, + std::string *ErrMsg) { + if (ErrMsg) *ErrMsg = "dlopen() not supported on this platform"; + return true; +} +#endif + +namespace llvm { +void *SearchForAddressOfSpecialSymbol(const char* symbolName); +} + +void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) { + // First check symbols added via AddSymbol(). + if (ExplicitSymbols) { + std::map<std::string, void *>::iterator I = + ExplicitSymbols->find(symbolName); + std::map<std::string, void *>::iterator E = ExplicitSymbols->end(); + + if (I != E) + return I->second; + } + +#if HAVE_DLFCN_H + // Now search the libraries. + SmartScopedLock<true> Lock(getMutex()); + if (OpenedHandles) { + for (std::vector<void *>::iterator I = OpenedHandles->begin(), + E = OpenedHandles->end(); I != E; ++I) { + //lt_ptr ptr = lt_dlsym(*I, symbolName); + void *ptr = dlsym(*I, symbolName); + if (ptr) { + return ptr; + } + } + } +#endif + + if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName)) + return Result; + +// This macro returns the address of a well-known, explicit symbol +#define EXPLICIT_SYMBOL(SYM) \ + if (!strcmp(symbolName, #SYM)) return &SYM + +// On linux we have a weird situation. The stderr/out/in symbols are both +// macros and global variables because of standards requirements. So, we +// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first. +#if defined(__linux__) + { + EXPLICIT_SYMBOL(stderr); + EXPLICIT_SYMBOL(stdout); + EXPLICIT_SYMBOL(stdin); + } +#else + // For everything else, we want to check to make sure the symbol isn't defined + // as a macro before using EXPLICIT_SYMBOL. + { +#ifndef stdin + EXPLICIT_SYMBOL(stdin); +#endif +#ifndef stdout + EXPLICIT_SYMBOL(stdout); +#endif +#ifndef stderr + EXPLICIT_SYMBOL(stderr); +#endif + } +#endif +#undef EXPLICIT_SYMBOL + + return 0; +} + +#endif // LLVM_ON_WIN32 |