From cbb70ce070d220642b038ea101d9c0f9fbf860d6 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Sun, 20 Feb 2011 12:57:14 +0000
Subject: Vendor import of llvm trunk r126079:
http://llvm.org/svn/llvm-project/llvm/trunk@126079
---
lib/Support/DynamicLibrary.cpp | 170 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 170 insertions(+)
create mode 100644 lib/Support/DynamicLibrary.cpp
(limited to 'lib/Support/DynamicLibrary.cpp')
diff --git a/lib/Support/DynamicLibrary.cpp b/lib/Support/DynamicLibrary.cpp
new file mode 100644
index 0000000..455c380
--- /dev/null
+++ b/lib/Support/DynamicLibrary.cpp
@@ -0,0 +1,170 @@
+//===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This header file implements the operating system DynamicLibrary concept.
+//
+// FIXME: This file leaks the ExplicitSymbols and OpenedHandles vector, and is
+// not thread safe!
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/Mutex.h"
+#include "llvm/Config/config.h"
+#include <cstdio>
+#include <cstring>
+#include <map>
+#include <vector>
+
+// Collection of symbol name/value pairs to be searched prior to any libraries.
+static std::map<std::string, void*> *ExplicitSymbols = 0;
+
+namespace {
+
+struct ExplicitSymbolsDeleter {
+ ~ExplicitSymbolsDeleter() {
+ if (ExplicitSymbols)
+ delete ExplicitSymbols;
+ }
+};
+
+}
+
+static ExplicitSymbolsDeleter Dummy;
+
+void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
+ void *symbolValue) {
+ if (ExplicitSymbols == 0)
+ ExplicitSymbols = new std::map<std::string, void*>();
+ (*ExplicitSymbols)[symbolName] = symbolValue;
+}
+
+#ifdef LLVM_ON_WIN32
+
+#include "Windows/DynamicLibrary.inc"
+
+#else
+
+#if HAVE_DLFCN_H
+#include <dlfcn.h>
+using namespace llvm;
+using namespace llvm::sys;
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//=== independent code.
+//===----------------------------------------------------------------------===//
+
+static std::vector<void *> *OpenedHandles = 0;
+
+
+static SmartMutex<true>& getMutex() {
+ static SmartMutex<true> HandlesMutex;
+ return HandlesMutex;
+}
+
+
+bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
+ std::string *ErrMsg) {
+ void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
+ if (H == 0) {
+ if (ErrMsg) *ErrMsg = dlerror();
+ return true;
+ }
+#ifdef __CYGWIN__
+ // Cygwin searches symbols only in the main
+ // with the handle of dlopen(NULL, RTLD_GLOBAL).
+ if (Filename == NULL)
+ H = RTLD_DEFAULT;
+#endif
+ SmartScopedLock<true> Lock(getMutex());
+ if (OpenedHandles == 0)
+ OpenedHandles = new std::vector<void *>();
+ OpenedHandles->push_back(H);
+ return false;
+}
+#else
+
+using namespace llvm;
+using namespace llvm::sys;
+
+bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
+ std::string *ErrMsg) {
+ if (ErrMsg) *ErrMsg = "dlopen() not supported on this platform";
+ return true;
+}
+#endif
+
+namespace llvm {
+void *SearchForAddressOfSpecialSymbol(const char* symbolName);
+}
+
+void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
+ // First check symbols added via AddSymbol().
+ if (ExplicitSymbols) {
+ std::map<std::string, void *>::iterator I =
+ ExplicitSymbols->find(symbolName);
+ std::map<std::string, void *>::iterator E = ExplicitSymbols->end();
+
+ if (I != E)
+ return I->second;
+ }
+
+#if HAVE_DLFCN_H
+ // Now search the libraries.
+ SmartScopedLock<true> Lock(getMutex());
+ if (OpenedHandles) {
+ for (std::vector<void *>::iterator I = OpenedHandles->begin(),
+ E = OpenedHandles->end(); I != E; ++I) {
+ //lt_ptr ptr = lt_dlsym(*I, symbolName);
+ void *ptr = dlsym(*I, symbolName);
+ if (ptr) {
+ return ptr;
+ }
+ }
+ }
+#endif
+
+ if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
+ return Result;
+
+// This macro returns the address of a well-known, explicit symbol
+#define EXPLICIT_SYMBOL(SYM) \
+ if (!strcmp(symbolName, #SYM)) return &SYM
+
+// On linux we have a weird situation. The stderr/out/in symbols are both
+// macros and global variables because of standards requirements. So, we
+// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
+#if defined(__linux__)
+ {
+ EXPLICIT_SYMBOL(stderr);
+ EXPLICIT_SYMBOL(stdout);
+ EXPLICIT_SYMBOL(stdin);
+ }
+#else
+ // For everything else, we want to check to make sure the symbol isn't defined
+ // as a macro before using EXPLICIT_SYMBOL.
+ {
+#ifndef stdin
+ EXPLICIT_SYMBOL(stdin);
+#endif
+#ifndef stdout
+ EXPLICIT_SYMBOL(stdout);
+#endif
+#ifndef stderr
+ EXPLICIT_SYMBOL(stderr);
+#endif
+ }
+#endif
+#undef EXPLICIT_SYMBOL
+
+ return 0;
+}
+
+#endif // LLVM_ON_WIN32
--
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