|
|
// Macros for correct module ordering.
#ifndef _CL_MODULES_H
#define _CL_MODULES_H
// The order of initialization of different compilation units is not
// specified in C++. AIX 4 has a linker which apparently does order
// the modules according to dependencies, so that low-level modules
// will be initialized earlier than the high-level modules which depend
// on them. I have a patch for GNU ld that does the same thing.
//
// But for now, I take a half-automatic approach to the correct module
// ordering problem: PROVIDE/REQUIRE, as in Common Lisp.
//
// CL_PROVIDE(module) must be the first code-generating entity in a module.
// Inline function definitions can precede it, but global variable/function/
// class definitions may not precede it.
// Afterwards, any number of CL_REQUIRE(othermodule) is allowed.
// At the end of the module, there must be a corresponding
// CL_PROVIDE_END(module). (Sorry for this, it's really needed.)
//
// These macros work only with g++, and only in optimizing mode. But who
// wants to use CLN with other C++ compilers anyway...
// How to apply these macros:
// 1. Find out about variables which need to be initialized.
// On Linux/ELF, you can use a command like
// $ nm -o libcln.a | grep -v ' [UTtRrW] ' | sort +1
// A symbol of type "D" or "d" lies in the preinitialized DATA section,
// a symbol of type "B" or "b" lies in the uninitialized BSS section.
// All of them have to be checked.
// - Those which contain POD (= plain old data, i.e. scalar values or
// class instances without nontrivial constructors) are already fully
// initialized by the linker and can be discarded from these considerations.
// - Those which are static variables inside a function (you recognize
// them: g++ appends a dot and a number to their name) are initialized
// the first time the function is entered. They can be discarded from
// our considerations as well.
// 2. Find out which of these variables are publically exposed (to the user of
// the library) through the library's include files, either directly or
// through inline functions, or indirectly through normal function calls.
// These variables can be referenced from any user module U, hence any
// such module must CL_REQUIRE(M) the variable's definition module M.
// Since there is no CL_REQUIRE_IF_NEEDED(M) macro (which is equivalent
// to CL_REQUIRE(M) if the required module will be part of the executable
// but does nothing if M is not used), we must preventively put the
// CL_REQUIRE(M) into the header file. Hopefully M is either used anyway
// or does not bring in too much code into the executable.
// 3. Variables which are not publicly exposed but used internally by the
// library can be handled by adding a CL_REQUIRE in all the library's
// modules which directly or indirectly use the variable.
// 4. Variables and functions which can be reasonably assumed to not be
// accessed or executed during initialization need not be treated.
// For example, I/O to external streams, exception handling facilities,
// number theory stuff, etc.
// OK, stop reading here, because it's getting obscene.
#if defined(__GNUC__) && defined(__OPTIMIZE__) && !(defined(__hppa__) && (__GNUC__ == 2) && (__GNUC_MINOR__ < 8)) && !defined(NO_PROVIDE_REQUIRE)
#ifdef ASM_UNDERSCORE
#define ASM_UNDERSCORE_PREFIX "_"
#else
#define ASM_UNDERSCORE_PREFIX ""
#endif
// Globalize a label defined in the same translation unit.
// See macro ASM_GLOBALIZE_LABEL in the gcc sources.
#if defined(__i386__) || defined(__m68k__) || defined(__mips__) || defined(__mips64__) || defined(__alpha__) || defined(__rs6000__)
// Some m68k systems use "xdef" or "global" or ".global"...
#define CL_GLOBALIZE_LABEL(label) __asm__("\t.globl " label);
#endif
#if defined(__sparc__) || defined(__sparc64__) || defined(__arm__) || defined(__ia64__)
// Some arm systems use "EXPORT" or ".globl"...
#define CL_GLOBALIZE_LABEL(label) __asm__("\t.global " label);
#endif
#if defined(__hppa__)
#define CL_GLOBALIZE_LABEL(label) __asm__("\t.EXPORT " label ",ENTRY,PRIV_LEV=3");
#endif
#if defined(__m88k__)
#define CL_GLOBALIZE_LABEL(label) __asm__("\tglobal " label);
#endif
#if defined(__convex__)
#define CL_GLOBALIZE_LABEL(label) __asm__(".globl " label);
#endif
#ifndef CL_GLOBALIZE_LABEL
#define CL_GLOBALIZE_LABEL(label)
#endif
#if defined(__rs6000__) || defined(_WIN32)
#define CL_GLOBALIZE_JUMP_LABEL(label) CL_GLOBALIZE_LABEL(#label)
#else
#define CL_GLOBALIZE_JUMP_LABEL(label)
#endif
#ifdef CL_NEED_GLOBALIZE_CTORDTOR
#define CL_GLOBALIZE_CTORDTOR_LABEL(label) CL_GLOBALIZE_LABEL(label)
#else
#define CL_GLOBALIZE_CTORDTOR_LABEL(label)
#endif
// Output a label inside a function.
// See macro ASM_OUTPUT_LABEL in the gcc sources.
#if defined(__hppa__)
// Some hppa (Linux) systems want `label:', HPUX used to use just `label'.
// I tried to find out, but was unable to find the assembler on my HPUX-11
// boxen so decided to potentially ditch the support (no joke). Please
// send an email if you can explain to me what's going on! (-rbk. 07/2001)
#define CL_OUTPUT_LABEL(label) ASM_VOLATILE ("\n" label ":")
#else
#define CL_OUTPUT_LABEL(label) ASM_VOLATILE ("\n" label ":")
#endif
// ASM_VOLATILE(string) is for asms without arguments only!!
#if ((__GNUC__ == 2) && (__GNUC_MINOR__ >= 91)) || (__GNUC__ >= 3)
// avoid warning caused by the volatile keyword
#define ASM_VOLATILE __asm__
#else
// need volatile to avoid reordering
#define ASM_VOLATILE __asm__ __volatile__
#endif
// CL_JUMP_TO(addr) jumps to an address, like goto *(void*)(addr),
// except that the latter inhibits inlining of the function containing it
// in gcc-2.95. For new CPUs, look for "jump" and "indirect_jump" in gcc's
// machine description.
#if defined(__i386__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp %*%0" : : "rm" ((void*)(addr)))
#endif
#if defined(__m68k__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp %0@" : : "a" ((void*)(addr)))
#endif
#if defined(__mips__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("%*j %0" : : "d" ((void*)(addr)))
#endif
#if defined(__sparc__) || defined(__sparc64__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp %0\n\tnop" : : "r" ((void*)(addr)))
#endif
#if defined(__alpha__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp $31,(%0),0" : : "r" ((void*)(addr)))
#endif
#if defined(__hppa__)
//#define CL_JUMP_TO(addr) ASM_VOLATILE("bv,n 0(%0)" : : "r" ((void*)(addr)))
#define CL_JUMP_TO(addr) ASM_VOLATILE("b " #addr "\n\tnop")
#endif
#if defined(__arm__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("mov pc,%0" : : "r" ((void*)(addr)))
#endif
#if defined(__rs6000__) || defined(__powerpc__) || defined(__ppc__)
//#define CL_JUMP_TO(addr) ASM_VOLATILE("mtctr %0\n\tbctr" : : "r" ((void*)(addr)))
#define CL_JUMP_TO(addr) ASM_VOLATILE("b " #addr)
#endif
#if defined(__m88k__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp %0" : : "r" ((void*)(addr)))
#endif
#if defined(__convex__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("jmp (%0)" : : "r" ((void*)(addr)))
#endif
#if defined(__ia64__)
#define CL_JUMP_TO(addr) ASM_VOLATILE("br " #addr)
#endif
#define CL_PROVIDE(module) \
extern "C" void cl_module__##module##__firstglobalfun () {} \ extern "C" void cl_module__##module##__ctorend (void); \ extern "C" void cl_module__##module##__dtorend (void); \ CL_GLOBALIZE_JUMP_LABEL(cl_module__##module##__ctorend) \ CL_GLOBALIZE_JUMP_LABEL(cl_module__##module##__dtorend) \ CL_GLOBALIZE_CTORDTOR_LABEL( \ ASM_UNDERSCORE_PREFIX CL_GLOBAL_CONSTRUCTOR_PREFIX \ "cl_module__" #module "__firstglobalfun") \ CL_GLOBALIZE_CTORDTOR_LABEL( \ ASM_UNDERSCORE_PREFIX CL_GLOBAL_DESTRUCTOR_PREFIX \ "cl_module__" #module "__firstglobalfun") \ static int cl_module__##module##__counter; \ struct cl_module__##module##__controller { \ inline cl_module__##module##__controller () \ { if (cl_module__##module##__counter++) \ { CL_JUMP_TO(cl_module__##module##__ctorend); } \ } \ inline ~cl_module__##module##__controller () \ { CL_OUTPUT_LABEL (ASM_UNDERSCORE_PREFIX "cl_module__" #module "__dtorend"); } \ }; \ static cl_module__##module##__controller cl_module__##module##__ctordummy; #define CL_PROVIDE_END(module) \
struct cl_module__##module##__destroyer { \ inline cl_module__##module##__destroyer () \ { CL_OUTPUT_LABEL (ASM_UNDERSCORE_PREFIX "cl_module__" #module "__ctorend"); } \ inline ~cl_module__##module##__destroyer () \ { if (--cl_module__##module##__counter) \ { CL_JUMP_TO(cl_module__##module##__dtorend); } \ } \ }; \ static cl_module__##module##__destroyer cl_module__##module##__dtordummy; #define CL_REQUIRE(module) \
extern "C" void cl_module__##module##__ctor (void) \ __asm__ (ASM_UNDERSCORE_PREFIX CL_GLOBAL_CONSTRUCTOR_PREFIX \ "cl_module__" #module "__firstglobalfun"); \ extern "C" void cl_module__##module##__dtor (void) \ __asm__ (ASM_UNDERSCORE_PREFIX CL_GLOBAL_DESTRUCTOR_PREFIX \ "cl_module__" #module "__firstglobalfun"); \ struct _CL_REQUIRE_CLASSNAME(module,__LINE__) { \ inline _CL_REQUIRE_CLASSNAME(module,__LINE__) () \ { cl_module__##module##__ctor (); } \ inline ~_CL_REQUIRE_CLASSNAME(module,__LINE__) () \ { cl_module__##module##__dtor (); } \ }; \ static _CL_REQUIRE_CLASSNAME(module,__LINE__) \ _CL_REQUIRE_CLASSNAME(module##_requirer,__LINE__); #define _CL_REQUIRE_CLASSNAME(module,line) __CL_REQUIRE_CLASSNAME(module,line)
#define __CL_REQUIRE_CLASSNAME(module,line) cl_module__##module##__##line
#else
#define CL_PROVIDE(module)
#define CL_PROVIDE_END(module)
#define CL_REQUIRE(module)
#endif
#endif /* _CL_MODULES_H */
|
