trampolines.c

kaffe Java 解释器语言,源码,Java的子集系统,开放源代码

/*
 * arm/trampolines.c
 * ARM trampolines codes for various occasions.
 *
 * Copyright (c) 1996, 1997
 *	Transvirtual Technologies, Inc.  All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file.
 */

#if defined(TRAMPOLINE_FUNCTION)
/*
 * If we have an explit function defined then use that.
 */
TRAMPOLINE_FUNCTION()

#else
/*
 * Otherwise we'll try to construct one.
 */
#if !defined(START_ASM_FUNC)

#ifdef __riscos__
#define	START_ASM_FUNC() "ALIGN\n\tEXPORT\t"
#else
#define	START_ASM_FUNC() ".text\n\t.align 4\n\t.globl "
#endif

#endif
#if !defined(END_ASM_FUNC)
#define	END_ASM_FUNC() ""
#endif
#if defined(HAVE_UNDERSCORED_C_NAMES)
#define	C_FUNC_NAME(FUNC) "_" #FUNC
#else
#define	C_FUNC_NAME(FUNC) #FUNC
#endif

#if defined(NO_SHARED_VMLIBRARY)

asm(
	START_ASM_FUNC() C_FUNC_NAME(arm_do_fixup_trampoline) "\n"
#ifdef __riscos__
"|" C_FUNC_NAME(arm_do_fixup_trampoline) "|\n"
#else
C_FUNC_NAME(arm_do_fixup_trampoline) ":				\n"
#endif
"	stmdb	sp!,{r0,r1,r2,r3,fp,ip,lr}\n"
"	add	fp, sp, #28\n"
"	mov	r0,ip\n"
"	bl	" C_FUNC_NAME(soft_fixup_trampoline) "		\n"
"	str	r0, [sp, #-4]\n"
"	ldmia	sp!,{r0,r1,r2,r3,fp,ip,lr}\n"
"	ldr	pc, [sp, #-32]\n"

	END_ASM_FUNC()
);

#else
/*
 * We need to create a seperate stack frame for the trampoline
 * so that we consider it as a seperate function when creating
 * a backtrace. Therefore, we have to push the fp and adjust it
 * according to the sp afterwards (we can't use the ip for this,
 * since that holds the method that is to be translated). Since
 * kaffe expects the stackframe to also contain the ip (since it's
 * normally used to save the sp), we have to push that one too,
 * although this trampoline doesn't use it itself. Removing the
 * stackframe is a little bit tricky, since we have to restore
 * all registers, but need to get the tranlated code into pc.
 * Therefore, the address of the translated code is pushed on
 * the stack, then the registers are restored and the saved
 * address is loaded into the pc afterwards.
 */
asm(
	START_ASM_FUNC() C_FUNC_NAME(arm_do_fixup_trampoline) "\n"
#ifdef __riscos__
"|" C_FUNC_NAME(arm_do_fixup_trampoline) "|\n"
#else
C_FUNC_NAME(arm_do_fixup_trampoline) ":				\n"
#endif
"	stmdb	sp!,{r0,r1,r2,r3,fp,ip,lr}\n"
"	add	fp, sp, #28\n"
"	mov	r0,ip\n"
"	bl	" C_FUNC_NAME(soft_fixup_trampoline) " (PLT)	\n"
"	str	r0, [sp, #-4]\n"
"	ldmia	sp!,{r0,r1,r2,r3,fp,ip,lr}\n"
"	ldr	pc, [sp, #-32]\n"

	END_ASM_FUNC()
);

#endif

#endif