1 //===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file implements the operating system DynamicLibrary concept.
12 // FIXME: This file leaks ExplicitSymbols and OpenedHandles!
14 //===----------------------------------------------------------------------===//
16 #include "llvm/ADT/StringMap.h"
17 #include "llvm/ADT/DenseSet.h"
18 #include "llvm/Support/DynamicLibrary.h"
19 #include "llvm/Support/Mutex.h"
20 #include "llvm/Config/config.h"
24 // Collection of symbol name/value pairs to be searched prior to any libraries.
25 static llvm::StringMap<void *> *ExplicitSymbols = 0;
29 struct ExplicitSymbolsDeleter {
30 ~ExplicitSymbolsDeleter() {
31 delete ExplicitSymbols;
37 static ExplicitSymbolsDeleter Dummy;
40 static llvm::sys::SmartMutex<true>& getMutex() {
41 static llvm::sys::SmartMutex<true> HandlesMutex;
45 void llvm::sys::DynamicLibrary::AddSymbol(StringRef symbolName,
47 SmartScopedLock<true> lock(getMutex());
48 if (ExplicitSymbols == 0)
49 ExplicitSymbols = new llvm::StringMap<void*>();
50 (*ExplicitSymbols)[symbolName] = symbolValue;
55 #include "Windows/DynamicLibrary.inc"
62 using namespace llvm::sys;
64 //===----------------------------------------------------------------------===//
65 //=== WARNING: Implementation here must contain only TRULY operating system
66 //=== independent code.
67 //===----------------------------------------------------------------------===//
69 static DenseSet<void *> *OpenedHandles = 0;
71 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
72 std::string *errMsg) {
73 void *handle = dlopen(filename, RTLD_LAZY|RTLD_GLOBAL);
75 if (errMsg) *errMsg = dlerror();
76 return DynamicLibrary();
80 // Cygwin searches symbols only in the main
81 // with the handle of dlopen(NULL, RTLD_GLOBAL).
83 handle = RTLD_DEFAULT;
86 SmartScopedLock<true> lock(getMutex());
87 if (OpenedHandles == 0)
88 OpenedHandles = new DenseSet<void *>();
90 // If we've already loaded this library, dlclose() the handle in order to
91 // keep the internal refcount at +1.
92 if (!OpenedHandles->insert(handle).second)
95 return DynamicLibrary(handle);
98 void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
101 return dlsym(Data, symbolName);
106 using namespace llvm;
107 using namespace llvm::sys;
109 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
110 std::string *errMsg) {
111 if (errMsg) *errMsg = "dlopen() not supported on this platform";
112 return DynamicLibrary();
115 void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
122 void *SearchForAddressOfSpecialSymbol(const char* symbolName);
125 void* DynamicLibrary::SearchForAddressOfSymbol(const char *symbolName) {
126 SmartScopedLock<true> Lock(getMutex());
128 // First check symbols added via AddSymbol().
129 if (ExplicitSymbols) {
130 StringMap<void *>::iterator i = ExplicitSymbols->find(symbolName);
132 if (i != ExplicitSymbols->end())
137 // Now search the libraries.
139 for (DenseSet<void *>::iterator I = OpenedHandles->begin(),
140 E = OpenedHandles->end(); I != E; ++I) {
141 //lt_ptr ptr = lt_dlsym(*I, symbolName);
142 void *ptr = dlsym(*I, symbolName);
150 if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
153 // This macro returns the address of a well-known, explicit symbol
154 #define EXPLICIT_SYMBOL(SYM) \
155 if (!strcmp(symbolName, #SYM)) return &SYM
157 // On linux we have a weird situation. The stderr/out/in symbols are both
158 // macros and global variables because of standards requirements. So, we
159 // boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
160 #if defined(__linux__)
162 EXPLICIT_SYMBOL(stderr);
163 EXPLICIT_SYMBOL(stdout);
164 EXPLICIT_SYMBOL(stdin);
167 // For everything else, we want to check to make sure the symbol isn't defined
168 // as a macro before using EXPLICIT_SYMBOL.
171 EXPLICIT_SYMBOL(stdin);
174 EXPLICIT_SYMBOL(stdout);
177 EXPLICIT_SYMBOL(stderr);
181 #undef EXPLICIT_SYMBOL
186 #endif // LLVM_ON_WIN32