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 //===----------------------------------------------------------------------===//
14 #include "llvm/System/DynamicLibrary.h"
15 #include "llvm/Support/ManagedStatic.h"
16 #include "llvm/System/RWMutex.h"
17 #include "llvm/Config/config.h"
23 // Collection of symbol name/value pairs to be searched prior to any libraries.
24 static std::map<std::string, void*> symbols;
25 static llvm::sys::SmartRWMutex<true> SymbolsLock;
27 void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
29 llvm::sys::SmartScopedWriter<true> Writer(&SymbolsLock);
30 symbols[symbolName] = symbolValue;
35 #include "Win32/DynamicLibrary.inc"
42 using namespace llvm::sys;
44 //===----------------------------------------------------------------------===//
45 //=== WARNING: Implementation here must contain only TRULY operating system
46 //=== independent code.
47 //===----------------------------------------------------------------------===//
49 static std::vector<void *> OpenedHandles;
52 bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
53 std::string *ErrMsg) {
54 SmartScopedWriter<true> Writer(&SymbolsLock);
55 void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
61 OpenedHandles.push_back(H);
65 void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
66 // First check symbols added via AddSymbol().
67 SymbolsLock.reader_acquire();
68 std::map<std::string, void *>::iterator I = symbols.find(symbolName);
69 std::map<std::string, void *>::iterator E = symbols.end();
70 SymbolsLock.reader_release();
75 SymbolsLock.writer_acquire();
76 // Now search the libraries.
77 for (std::vector<void *>::iterator I = OpenedHandles.begin(),
78 E = OpenedHandles.end(); I != E; ++I) {
79 //lt_ptr ptr = lt_dlsym(*I, symbolName);
80 void *ptr = dlsym(*I, symbolName);
82 SymbolsLock.writer_release();
86 SymbolsLock.writer_release();
88 #define EXPLICIT_SYMBOL(SYM) \
89 extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
91 // If this is darwin, it has some funky issues, try to solve them here. Some
92 // important symbols are marked 'private external' which doesn't allow
93 // SearchForAddressOfSymbol to find them. As such, we special case them here,
94 // there is only a small handful of them.
98 EXPLICIT_SYMBOL(__ashldi3);
99 EXPLICIT_SYMBOL(__ashrdi3);
100 EXPLICIT_SYMBOL(__cmpdi2);
101 EXPLICIT_SYMBOL(__divdi3);
102 EXPLICIT_SYMBOL(__eprintf);
103 EXPLICIT_SYMBOL(__fixdfdi);
104 EXPLICIT_SYMBOL(__fixsfdi);
105 EXPLICIT_SYMBOL(__fixunsdfdi);
106 EXPLICIT_SYMBOL(__fixunssfdi);
107 EXPLICIT_SYMBOL(__floatdidf);
108 EXPLICIT_SYMBOL(__floatdisf);
109 EXPLICIT_SYMBOL(__lshrdi3);
110 EXPLICIT_SYMBOL(__moddi3);
111 EXPLICIT_SYMBOL(__udivdi3);
112 EXPLICIT_SYMBOL(__umoddi3);
118 EXPLICIT_SYMBOL(_alloca);
119 EXPLICIT_SYMBOL(__main);
123 #undef EXPLICIT_SYMBOL
125 // This macro returns the address of a well-known, explicit symbol
126 #define EXPLICIT_SYMBOL(SYM) \
127 if (!strcmp(symbolName, #SYM)) return &SYM
129 // On linux we have a weird situation. The stderr/out/in symbols are both
130 // macros and global variables because of standards requirements. So, we
131 // boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
132 #if defined(__linux__)
134 EXPLICIT_SYMBOL(stderr);
135 EXPLICIT_SYMBOL(stdout);
136 EXPLICIT_SYMBOL(stdin);
139 // For everything else, we want to check to make sure the symbol isn't defined
140 // as a macro before using EXPLICIT_SYMBOL.
143 EXPLICIT_SYMBOL(stdin);
146 EXPLICIT_SYMBOL(stdout);
149 EXPLICIT_SYMBOL(stderr);
153 #undef EXPLICIT_SYMBOL
158 #endif // LLVM_ON_WIN32