llvm/lib/Support/SearchForAddressOfSpecialSymbol.cpp
2016-04-05 20:45:04 +00:00

59 lines
1.7 KiB
C++

//===- SearchForAddressOfSpecialSymbol.cpp - Function addresses -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file pulls the addresses of certain symbols out of the linker. It must
// include as few header files as possible because it declares the symbols as
// void*, which would conflict with the actual symbol type if any header
// declared it.
//
//===----------------------------------------------------------------------===//
#include <string.h>
// Must declare the symbols in the global namespace.
static void *DoSearch(const char* symbolName) {
#define EXPLICIT_SYMBOL(SYM) \
extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
// If this is darwin, it has some funky issues, try to solve them here. Some
// important symbols are marked 'private external' which doesn't allow
// SearchForAddressOfSymbol to find them. As such, we special case them here,
// there is only a small handful of them.
#ifdef __APPLE__
{
// __eprintf is sometimes used for assert() handling on x86.
//
// FIXME: Currently disabled when using Clang, as we don't always have our
// runtime support libraries available.
#ifndef __clang__
#ifdef __i386__
EXPLICIT_SYMBOL(__eprintf);
#endif
#endif
}
#endif
#ifdef __CYGWIN__
{
EXPLICIT_SYMBOL(_alloca);
EXPLICIT_SYMBOL(__main);
}
#endif
#undef EXPLICIT_SYMBOL
return nullptr;
}
namespace llvm {
void *SearchForAddressOfSpecialSymbol(const char* symbolName) {
return DoSearch(symbolName);
}
} // namespace llvm