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 file implements the operating system DynamicLibrary concept.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Support/DynamicLibrary.h"
15 #include "llvm-c/Support.h"
16 #include "llvm/ADT/DenseSet.h"
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/Config/config.h"
19 #include "llvm/Support/ManagedStatic.h"
20 #include "llvm/Support/Mutex.h"
26 using namespace llvm::sys;
28 // All methods for HandleSet should be used holding SymbolsMutex.
29 class DynamicLibrary::HandleSet {
30 typedef std::vector<void *> HandleList;
35 static void *DLOpen(const char *Filename, std::string *Err);
36 static void DLClose(void *Handle);
37 static void *DLSym(void *Handle, const char *Symbol);
39 HandleSet() : Process(nullptr) {}
42 HandleList::iterator Find(void *Handle) {
43 return std::find(Handles.begin(), Handles.end(), Handle);
46 bool Contains(void *Handle) {
47 return Handle == Process || Find(Handle) != Handles.end();
50 bool AddLibrary(void *Handle, bool IsProcess = false, bool CanClose = true) {
52 assert((Handle == this ? IsProcess : !IsProcess) && "Bad Handle.");
55 if (LLVM_LIKELY(!IsProcess)) {
56 if (Find(Handle) != Handles.end()) {
61 Handles.push_back(Handle);
67 if (Process == Handle)
76 void *Lookup(const char *Symbol) {
77 // Process handle gets first try.
79 if (void *Ptr = DLSym(Process, Symbol))
82 for (void *Handle : Handles)
83 assert(!DLSym(Handle, Symbol) && "Symbol exists in non process handle");
86 // Iterate in reverse, so newer libraries/symbols override older.
87 for (auto &&I = Handles.rbegin(), E = Handles.rend(); I != E; ++I) {
88 if (void *Ptr = DLSym(*I, Symbol))
97 // Collection of symbol name/value pairs to be searched prior to any libraries.
98 static llvm::ManagedStatic<llvm::StringMap<void *>> ExplicitSymbols;
99 // Collection of known library handles.
100 static llvm::ManagedStatic<DynamicLibrary::HandleSet> OpenedHandles;
101 // Lock for ExplicitSymbols and OpenedHandles.
102 static llvm::ManagedStatic<llvm::sys::SmartMutex<true>> SymbolsMutex;
107 #include "Windows/DynamicLibrary.inc"
111 #include "Unix/DynamicLibrary.inc"
115 char DynamicLibrary::Invalid;
118 void *SearchForAddressOfSpecialSymbol(const char *SymbolName) {
119 return DoSearch(SymbolName); // DynamicLibrary.inc
123 void DynamicLibrary::AddSymbol(StringRef SymbolName, void *SymbolValue) {
124 SmartScopedLock<true> Lock(*SymbolsMutex);
125 (*ExplicitSymbols)[SymbolName] = SymbolValue;
128 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *FileName,
130 // Force OpenedHandles to be added into the ManagedStatic list before any
131 // ManagedStatic can be added from static constructors in HandleSet::DLOpen.
132 HandleSet& HS = *OpenedHandles;
134 void *Handle = HandleSet::DLOpen(FileName, Err);
135 if (Handle != &Invalid) {
136 SmartScopedLock<true> Lock(*SymbolsMutex);
137 HS.AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
140 return DynamicLibrary(Handle);
143 DynamicLibrary DynamicLibrary::addPermanentLibrary(void *Handle,
145 SmartScopedLock<true> Lock(*SymbolsMutex);
146 // If we've already loaded this library, tell the caller.
147 if (!OpenedHandles->AddLibrary(Handle, /*IsProcess*/false, /*CanClose*/false))
148 *Err = "Library already loaded";
150 return DynamicLibrary(Handle);
153 void *DynamicLibrary::getAddressOfSymbol(const char *SymbolName) {
156 return HandleSet::DLSym(Data, SymbolName);
159 void *DynamicLibrary::SearchForAddressOfSymbol(const char *SymbolName) {
161 SmartScopedLock<true> Lock(*SymbolsMutex);
163 // First check symbols added via AddSymbol().
164 if (ExplicitSymbols.isConstructed()) {
165 StringMap<void *>::iterator i = ExplicitSymbols->find(SymbolName);
167 if (i != ExplicitSymbols->end())
171 // Now search the libraries.
172 if (OpenedHandles.isConstructed()) {
173 if (void *Ptr = OpenedHandles->Lookup(SymbolName))
178 return llvm::SearchForAddressOfSpecialSymbol(SymbolName);
181 //===----------------------------------------------------------------------===//
183 //===----------------------------------------------------------------------===//
185 LLVMBool LLVMLoadLibraryPermanently(const char *Filename) {
186 return llvm::sys::DynamicLibrary::LoadLibraryPermanently(Filename);
189 void *LLVMSearchForAddressOfSymbol(const char *symbolName) {
190 return llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(symbolName);
193 void LLVMAddSymbol(const char *symbolName, void *symbolValue) {
194 return llvm::sys::DynamicLibrary::AddSymbol(symbolName, symbolValue);