1//===- Win32/DynamicLibrary.cpp - Win32 DL Implementation -------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the Win32 specific implementation of DynamicLibrary.
11//
12//===----------------------------------------------------------------------===//
13
14#include "WindowsSupport.h"
15
16#ifdef __MINGW32__
17 #include <imagehlp.h>
18#else
19 #include <dbghelp.h>
20#endif
21
22#ifdef _MSC_VER
23 #include <ntverp.h>
24#endif
25
26namespace llvm {
27using namespace sys;
28
29//===----------------------------------------------------------------------===//
30//=== WARNING: Implementation here must contain only Win32 specific code
31//===          and must not be UNIX code.
32//===----------------------------------------------------------------------===//
33
34typedef BOOL (WINAPI *fpEnumerateLoadedModules)(HANDLE,PENUMLOADED_MODULES_CALLBACK64,PVOID);
35static fpEnumerateLoadedModules fEnumerateLoadedModules;
36static llvm::ManagedStatic<DenseSet<HMODULE> > OpenedHandles;
37
38static bool loadDebugHelp(void) {
39  HMODULE hLib = ::LoadLibraryW(L"Dbghelp.dll");
40  if (hLib) {
41    fEnumerateLoadedModules = (fpEnumerateLoadedModules)
42      ::GetProcAddress(hLib, "EnumerateLoadedModules64");
43  }
44  return fEnumerateLoadedModules != 0;
45}
46
47static BOOL CALLBACK
48ELM_Callback(PCSTR ModuleName, DWORD64 ModuleBase,
49             ULONG ModuleSize, PVOID UserContext) {
50  OpenedHandles->insert((HMODULE)ModuleBase);
51  return TRUE;
52}
53
54DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
55                                                   std::string *errMsg) {
56  SmartScopedLock<true> lock(*SymbolsMutex);
57
58  if (!filename) {
59    // When no file is specified, enumerate all DLLs and EXEs in the process.
60    if (!fEnumerateLoadedModules) {
61      if (!loadDebugHelp()) {
62        assert(false && "These APIs should always be available");
63        return DynamicLibrary();
64      }
65    }
66
67    fEnumerateLoadedModules(GetCurrentProcess(), ELM_Callback, 0);
68    // Dummy library that represents "search all handles".
69    // This is mostly to ensure that the return value still shows up as "valid".
70    return DynamicLibrary(&OpenedHandles);
71  }
72
73  SmallVector<wchar_t, MAX_PATH> filenameUnicode;
74  if (std::error_code ec = windows::UTF8ToUTF16(filename, filenameUnicode)) {
75    SetLastError(ec.value());
76    MakeErrMsg(errMsg, std::string(filename) + ": Can't convert to UTF-16");
77    return DynamicLibrary();
78  }
79
80  HMODULE a_handle = LoadLibraryW(filenameUnicode.data());
81
82  if (a_handle == 0) {
83    MakeErrMsg(errMsg, std::string(filename) + ": Can't open");
84    return DynamicLibrary();
85  }
86
87  // If we've already loaded this library, FreeLibrary() the handle in order to
88  // keep the internal refcount at +1.
89  if (!OpenedHandles->insert(a_handle).second)
90    FreeLibrary(a_handle);
91
92  return DynamicLibrary(a_handle);
93}
94
95DynamicLibrary DynamicLibrary::addPermanentLibrary(void *handle,
96                                                   std::string *errMsg) {
97  SmartScopedLock<true> lock(*SymbolsMutex);
98  // If we've already loaded this library, tell the caller.
99  if (!OpenedHandles->insert((HMODULE)handle).second) {
100    MakeErrMsg(errMsg, "Library already loaded");
101    return DynamicLibrary();
102  }
103
104  return DynamicLibrary(handle);
105}
106
107// Stack probing routines are in the support library (e.g. libgcc), but we don't
108// have dynamic linking on windows. Provide a hook.
109#define EXPLICIT_SYMBOL(SYM)                    \
110  extern "C" { extern void *SYM; }
111#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
112
113#ifdef _M_IX86
114// Win32 on x86 implements certain single-precision math functions as macros.
115// These functions are not exported by the DLL, but will still be needed
116// for symbol-resolution by the JIT loader. Therefore, this Support libray
117// provides helper functions with the same implementation.
118
119#define INLINE_DEF_SYMBOL1(TYP, SYM)                                           \
120  extern "C" TYP inline_##SYM(TYP _X) { return SYM(_X); }
121#define INLINE_DEF_SYMBOL2(TYP, SYM)                                           \
122  extern "C" TYP inline_##SYM(TYP _X, TYP _Y) { return SYM(_X, _Y); }
123#endif
124
125#include "explicit_symbols.inc"
126
127#undef EXPLICIT_SYMBOL
128#undef EXPLICIT_SYMBOL2
129#undef INLINE_DEF_SYMBOL1
130#undef INLINE_DEF_SYMBOL2
131
132void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
133  SmartScopedLock<true> Lock(*SymbolsMutex);
134
135  // First check symbols added via AddSymbol().
136  if (ExplicitSymbols.isConstructed()) {
137    StringMap<void *>::iterator i = ExplicitSymbols->find(symbolName);
138
139    if (i != ExplicitSymbols->end())
140      return i->second;
141  }
142
143  // Now search the libraries.
144  if (OpenedHandles.isConstructed()) {
145    for (DenseSet<HMODULE>::iterator I = OpenedHandles->begin(),
146         E = OpenedHandles->end(); I != E; ++I) {
147      FARPROC ptr = GetProcAddress((HMODULE)*I, symbolName);
148      if (ptr) {
149        return (void *)(intptr_t)ptr;
150      }
151    }
152  }
153
154#define EXPLICIT_SYMBOL(SYM)                                                   \
155  if (!strcmp(symbolName, #SYM))                                               \
156    return (void *)&SYM;
157#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO)                                       \
158  if (!strcmp(symbolName, #SYMFROM))                                           \
159    return (void *)&SYMTO;
160
161#ifdef _M_IX86
162#define INLINE_DEF_SYMBOL1(TYP, SYM)                                           \
163  if (!strcmp(symbolName, #SYM))                                               \
164    return (void *)&inline_##SYM;
165#define INLINE_DEF_SYMBOL2(TYP, SYM) INLINE_DEF_SYMBOL1(TYP, SYM)
166#endif
167
168  {
169#include "explicit_symbols.inc"
170  }
171
172#undef EXPLICIT_SYMBOL
173#undef EXPLICIT_SYMBOL2
174#undef INLINE_DEF_SYMBOL1
175#undef INLINE_DEF_SYMBOL2
176
177  return 0;
178}
179
180void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
181  if (!isValid())
182    return NULL;
183  if (Data == &OpenedHandles)
184    return SearchForAddressOfSymbol(symbolName);
185  return (void *)(intptr_t)GetProcAddress((HMODULE)Data, symbolName);
186}
187
188}
189