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 the ExplicitSymbols and OpenedHandles vector, and is
15 //===----------------------------------------------------------------------===//
17 #include "llvm/System/DynamicLibrary.h"
18 #include "llvm/Config/config.h"
24 // Collection of symbol name/value pairs to be searched prior to any libraries.
25 static std::map<std::string, void*> *ExplicitSymbols = 0;
27 static struct ExplicitSymbolsDeleter {
28 ~ExplicitSymbolsDeleter() {
30 delete ExplicitSymbols;
34 void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
36 if (ExplicitSymbols == 0)
37 ExplicitSymbols = new std::map<std::string, void*>();
38 (*ExplicitSymbols)[symbolName] = symbolValue;
43 #include "Win32/DynamicLibrary.inc"
50 using namespace llvm::sys;
52 //===----------------------------------------------------------------------===//
53 //=== WARNING: Implementation here must contain only TRULY operating system
54 //=== independent code.
55 //===----------------------------------------------------------------------===//
57 static std::vector<void *> *OpenedHandles = 0;
60 bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
61 std::string *ErrMsg) {
62 void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
64 if (ErrMsg) *ErrMsg = dlerror();
67 if (OpenedHandles == 0)
68 OpenedHandles = new std::vector<void *>();
69 OpenedHandles->push_back(H);
75 using namespace llvm::sys;
77 bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
78 std::string *ErrMsg) {
79 if (ErrMsg) *ErrMsg = "dlopen() not supported on this platform";
85 void *SearchForAddressOfSpecialSymbol(const char* symbolName);
88 void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
89 // First check symbols added via AddSymbol().
90 if (ExplicitSymbols) {
91 std::map<std::string, void *>::iterator I =
92 ExplicitSymbols->find(symbolName);
93 std::map<std::string, void *>::iterator E = ExplicitSymbols->end();
100 // Now search the libraries.
102 for (std::vector<void *>::iterator I = OpenedHandles->begin(),
103 E = OpenedHandles->end(); I != E; ++I) {
104 //lt_ptr ptr = lt_dlsym(*I, symbolName);
105 void *ptr = dlsym(*I, symbolName);
113 if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
116 // This macro returns the address of a well-known, explicit symbol
117 #define EXPLICIT_SYMBOL(SYM) \
118 if (!strcmp(symbolName, #SYM)) return &SYM
120 // On linux we have a weird situation. The stderr/out/in symbols are both
121 // macros and global variables because of standards requirements. So, we
122 // boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
123 #if defined(__linux__)
125 EXPLICIT_SYMBOL(stderr);
126 EXPLICIT_SYMBOL(stdout);
127 EXPLICIT_SYMBOL(stdin);
130 // For everything else, we want to check to make sure the symbol isn't defined
131 // as a macro before using EXPLICIT_SYMBOL.
134 EXPLICIT_SYMBOL(stdin);
137 EXPLICIT_SYMBOL(stdout);
140 EXPLICIT_SYMBOL(stderr);
144 #undef EXPLICIT_SYMBOL
149 #endif // LLVM_ON_WIN32