1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
//===- Win32/DynamicLibrary.cpp - Win32 DL Implementation -------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file provides the Win32 specific implementation of DynamicLibrary.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/Windows/WindowsSupport.h"
#include "llvm/Support/raw_ostream.h"
#include <psapi.h>
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only Win32 specific code
//=== and must not be UNIX code.
//===----------------------------------------------------------------------===//
DynamicLibrary::HandleSet::~HandleSet() {
for (void *Handle : llvm::reverse(Handles))
FreeLibrary(HMODULE(Handle));
// 'Process' should not be released on Windows.
assert((!Process || Process == this) && "Bad Handle");
// llvm_shutdown called, Return to default
DynamicLibrary::SearchOrder = DynamicLibrary::SO_Linker;
}
void *DynamicLibrary::HandleSet::DLOpen(const char *File, std::string *Err) {
// Create the instance and return it to be the *Process* handle
// simillar to dlopen(NULL, RTLD_LAZY|RTLD_GLOBAL)
if (!File)
return &getGlobals().OpenedHandles;
SmallVector<wchar_t, MAX_PATH> FileUnicode;
if (std::error_code ec = windows::UTF8ToUTF16(File, FileUnicode)) {
SetLastError(ec.value());
MakeErrMsg(Err, std::string(File) + ": Can't convert to UTF-16");
return &DynamicLibrary::Invalid;
}
HMODULE Handle = LoadLibraryW(FileUnicode.data());
if (Handle == NULL) {
MakeErrMsg(Err, std::string(File) + ": Can't open");
return &DynamicLibrary::Invalid;
}
return reinterpret_cast<void *>(Handle);
}
static DynamicLibrary::HandleSet *IsOpenedHandlesInstance(void *Handle) {
DynamicLibrary::HandleSet &Inst = getGlobals().OpenedHandles;
return Handle == &Inst ? &Inst : nullptr;
}
void DynamicLibrary::HandleSet::DLClose(void *Handle) {
if (HandleSet *HS = IsOpenedHandlesInstance(Handle))
HS->Process = nullptr; // Just drop the *Process* handle.
else
FreeLibrary((HMODULE)Handle);
}
static bool GetProcessModules(HANDLE H, DWORD &Bytes, HMODULE *Data = nullptr) {
// EnumProcessModules will fail on Windows 64 while some versions of
// MingW-32 don't have EnumProcessModulesEx.
if (
#ifdef _WIN64
!EnumProcessModulesEx(H, Data, Bytes, &Bytes, LIST_MODULES_64BIT)
#else
!EnumProcessModules(H, Data, Bytes, &Bytes)
#endif
) {
std::string Err;
if (MakeErrMsg(&Err, "EnumProcessModules failure"))
llvm::errs() << Err << "\n";
return false;
}
return true;
}
void *DynamicLibrary::HandleSet::DLSym(void *Handle, const char *Symbol) {
HandleSet *HS = IsOpenedHandlesInstance(Handle);
if (!HS)
return (void *)uintptr_t(GetProcAddress((HMODULE)Handle, Symbol));
// Could have done a dlclose on the *Process* handle
if (!HS->Process)
return nullptr;
// Trials indicate EnumProcessModulesEx is consistantly faster than using
// EnumerateLoadedModules64 or CreateToolhelp32Snapshot.
//
// | Handles | DbgHelp.dll | CreateSnapshot | EnumProcessModulesEx
// |=========|=============|========================================
// | 37 | 0.0000585 * | 0.0003031 | 0.0000152
// | 1020 | 0.0026310 * | 0.0121598 | 0.0002683
// | 2084 | 0.0149418 * | 0.0369936 | 0.0005610
//
// * Not including the load time of Dbghelp.dll (~.005 sec)
//
// There's still a case to somehow cache the result of EnumProcessModulesEx
// across invocations, but the complication of doing that properly...
// Possibly using LdrRegisterDllNotification to invalidate the cache?
DWORD Bytes = 0;
HMODULE Self = HMODULE(GetCurrentProcess());
if (!GetProcessModules(Self, Bytes))
return nullptr;
// Get the most recent list in case any modules added/removed between calls
// to EnumProcessModulesEx that gets the amount of, then copies the HMODULES.
// MSDN is pretty clear that if the module list changes during the call to
// EnumProcessModulesEx the results should not be used.
std::vector<HMODULE> Handles;
do {
assert(Bytes && ((Bytes % sizeof(HMODULE)) == 0) &&
"Should have at least one module and be aligned");
Handles.resize(Bytes / sizeof(HMODULE));
if (!GetProcessModules(Self, Bytes, Handles.data()))
return nullptr;
} while (Bytes != (Handles.size() * sizeof(HMODULE)));
// Try EXE first, mirroring what dlsym(dlopen(NULL)) does.
if (FARPROC Ptr = GetProcAddress(HMODULE(Handles.front()), Symbol))
return (void *)uintptr_t(Ptr);
if (Handles.size() > 1) {
// This is different behaviour than what Posix dlsym(dlopen(NULL)) does.
// Doing that here is causing real problems for the JIT where msvc.dll
// and ucrt.dll can define the same symbols. The runtime linker will choose
// symbols from ucrt.dll first, but iterating NOT in reverse here would
// mean that the msvc.dll versions would be returned.
for (auto I = Handles.rbegin(), E = Handles.rend() - 1; I != E; ++I) {
if (FARPROC Ptr = GetProcAddress(HMODULE(*I), Symbol))
return (void *)uintptr_t(Ptr);
}
}
return nullptr;
}
// Stack probing routines are in the support library (e.g. libgcc), but we don't
// have dynamic linking on windows. Provide a hook.
#define EXPLICIT_SYMBOL(SYM) \
extern "C" { \
extern void *SYM; \
}
#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
#ifdef _M_IX86
// Win32 on x86 implements certain single-precision math functions as macros.
// These functions are not exported by the DLL, but will still be needed
// for symbol-resolution by the JIT loader. Therefore, this Support libray
// provides helper functions with the same implementation.
#define INLINE_DEF_SYMBOL1(TYP, SYM) \
extern "C" TYP inline_##SYM(TYP _X) { return SYM(_X); }
#define INLINE_DEF_SYMBOL2(TYP, SYM) \
extern "C" TYP inline_##SYM(TYP _X, TYP _Y) { return SYM(_X, _Y); }
#endif
#include "explicit_symbols.inc"
#undef EXPLICIT_SYMBOL
#undef EXPLICIT_SYMBOL2
#undef INLINE_DEF_SYMBOL1
#undef INLINE_DEF_SYMBOL2
static void *DoSearch(const char *SymbolName) {
#define EXPLICIT_SYMBOL(SYM) \
if (!strcmp(SymbolName, #SYM)) \
return (void *)&SYM;
#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) \
if (!strcmp(SymbolName, #SYMFROM)) \
return (void *)&SYMTO;
#ifdef _M_IX86
#define INLINE_DEF_SYMBOL1(TYP, SYM) \
if (!strcmp(SymbolName, #SYM)) \
return (void *)&inline_##SYM;
#define INLINE_DEF_SYMBOL2(TYP, SYM) INLINE_DEF_SYMBOL1(TYP, SYM)
#endif
{
#include "explicit_symbols.inc"
}
#undef EXPLICIT_SYMBOL
#undef EXPLICIT_SYMBOL2
#undef INLINE_DEF_SYMBOL1
#undef INLINE_DEF_SYMBOL2
return nullptr;
}
|
