mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-27 13:30:05 +00:00
0f8b53f19d
and put @file directives on their own comment line. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65920 91177308-0d34-0410-b5e6-96231b3b80d8
80 lines
3.3 KiB
C++
80 lines
3.3 KiB
C++
//===- llvm/System/IncludeFile.h - Ensure Linking Of Library ---*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the FORCE_DEFINING_FILE_TO_BE_LINKED and DEFINE_FILE_FOR
|
|
// macros.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SYSTEM_INCLUDEFILE_H
|
|
#define LLVM_SYSTEM_INCLUDEFILE_H
|
|
|
|
/// This macro is the public interface that IncludeFile.h exports. This gives
|
|
/// us the option to implement the "link the definition" capability in any
|
|
/// manner that we choose. All header files that depend on a specific .cpp
|
|
/// file being linked at run time should use this macro instead of the
|
|
/// IncludeFile class directly.
|
|
///
|
|
/// For example, foo.h would use:<br/>
|
|
/// <tt>FORCE_DEFINING_FILE_TO_BE_LINKED(foo)</tt><br/>
|
|
///
|
|
/// And, foo.cp would use:<br/>
|
|
/// <tt>DEFINING_FILE_FOR(foo)</tt><br/>
|
|
#ifdef __GNUC__
|
|
// If the `used' attribute is available, use it to create a variable
|
|
// with an initializer that will force the linking of the defining file.
|
|
#define FORCE_DEFINING_FILE_TO_BE_LINKED(name) \
|
|
namespace llvm { \
|
|
extern const char name ## LinkVar; \
|
|
__attribute__((used)) static const char *const name ## LinkObj = \
|
|
&name ## LinkVar; \
|
|
}
|
|
#else
|
|
// Otherwise use a constructor call.
|
|
#define FORCE_DEFINING_FILE_TO_BE_LINKED(name) \
|
|
namespace llvm { \
|
|
extern const char name ## LinkVar; \
|
|
static const IncludeFile name ## LinkObj ( &name ## LinkVar ); \
|
|
}
|
|
#endif
|
|
|
|
/// This macro is the counterpart to FORCE_DEFINING_FILE_TO_BE_LINKED. It should
|
|
/// be used in a .cpp file to define the name referenced in a header file that
|
|
/// will cause linkage of the .cpp file. It should only be used at extern level.
|
|
#define DEFINING_FILE_FOR(name) \
|
|
namespace llvm { const char name ## LinkVar = 0; }
|
|
|
|
namespace llvm {
|
|
|
|
/// This class is used in the implementation of FORCE_DEFINING_FILE_TO_BE_LINKED
|
|
/// macro to make sure that the implementation of a header file is included
|
|
/// into a tool that uses the header. This is solely
|
|
/// to overcome problems linking .a files and not getting the implementation
|
|
/// of compilation units we need. This is commonly an issue with the various
|
|
/// Passes but also occurs elsewhere in LLVM. We like to use .a files because
|
|
/// they link faster and provide the smallest executables. However, sometimes
|
|
/// those executables are too small, if the program doesn't reference something
|
|
/// that might be needed, especially by a loaded share object. This little class
|
|
/// helps to resolve that problem. The basic strategy is to use this class in
|
|
/// a header file and pass the address of a variable to the constructor. If the
|
|
/// variable is defined in the header file's corresponding .cpp file then all
|
|
/// tools/libraries that \#include the header file will require the .cpp as
|
|
/// well.
|
|
/// For example:<br/>
|
|
/// <tt>extern int LinkMyCodeStub;</tt><br/>
|
|
/// <tt>static IncludeFile LinkMyModule(&LinkMyCodeStub);</tt><br/>
|
|
/// @brief Class to ensure linking of corresponding object file.
|
|
struct IncludeFile {
|
|
explicit IncludeFile(const void *);
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|