1 /*
2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
4 *
5 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
6 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
7 *
8 * Permission is hereby granted to use or copy this program
9 * for any purpose, provided the above notices are retained on all copies.
10 * Permission to modify the code and to distribute modified code is granted,
11 * provided the above notices are retained, and a notice that the code was
12 * modified is included with the above copyright notice.
13 */
14 /* Boehm, November 17, 1995 12:13 pm PST */
15 # include "private/gc_priv.h"
16 # include <stdio.h>
17 # include <setjmp.h>
18 # if defined(OS2) || defined(CX_UX)
19 # define _setjmp(b) setjmp(b)
20 # define _longjmp(b,v) longjmp(b,v)
21 # endif
22 # ifdef AMIGA
23 # ifndef __GNUC__
24 # include <dos.h>
25 # else
26 # include <machine/reg.h>
27 # endif
28 # endif
29
30 #if defined(__MWERKS__) && !defined(POWERPC)
31
PushMacRegisters()32 asm static void PushMacRegisters()
33 {
34 sub.w #4,sp // reserve space for one parameter.
35 move.l a2,(sp)
36 jsr GC_push_one
37 move.l a3,(sp)
38 jsr GC_push_one
39 move.l a4,(sp)
40 jsr GC_push_one
41 # if !__option(a6frames)
42 // <pcb> perhaps a6 should be pushed if stack frames are not being used.
43 move.l a6,(sp)
44 jsr GC_push_one
45 # endif
46 // skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
47 move.l d2,(sp)
48 jsr GC_push_one
49 move.l d3,(sp)
50 jsr GC_push_one
51 move.l d4,(sp)
52 jsr GC_push_one
53 move.l d5,(sp)
54 jsr GC_push_one
55 move.l d6,(sp)
56 jsr GC_push_one
57 move.l d7,(sp)
58 jsr GC_push_one
59 add.w #4,sp // fix stack.
60 rts
61 }
62
63 #endif /* __MWERKS__ */
64
65 # if defined(SPARC) || defined(IA64)
66 /* Value returned from register flushing routine; either sp (SPARC) */
67 /* or ar.bsp (IA64) */
68 ptr_t GC_save_regs_ret_val;
69 # endif
70
71 /* Routine to mark from registers that are preserved by the C compiler. */
72 /* This must be ported to every new architecture. It is noe optional, */
73 /* and should not be used on platforms that are either UNIX-like, or */
74 /* require thread support. */
75
76 #undef HAVE_PUSH_REGS
77
78 #if defined(USE_ASM_PUSH_REGS)
79 # define HAVE_PUSH_REGS
80 #else /* No asm implementation */
GC_push_regs()81 void GC_push_regs()
82 {
83 # if defined(M68K) && defined(AMIGA)
84 /* AMIGA - could be replaced by generic code */
85 /* a0, a1, d0 and d1 are caller save */
86
87 # ifdef __GNUC__
88 asm("subq.w &0x4,%sp"); /* allocate word on top of stack */
89
90 asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
91 asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
92 asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
93 asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
94 asm("mov.l %a6,(%sp)"); asm("jsr _GC_push_one");
95 /* Skip frame pointer and stack pointer */
96 asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
97 asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
98 asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
99 asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
100 asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
101 asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
102
103 asm("addq.w &0x4,%sp"); /* put stack back where it was */
104 # define HAVE_PUSH_REGS
105 # else /* !__GNUC__ */
106 GC_push_one(getreg(REG_A2));
107 GC_push_one(getreg(REG_A3));
108 # ifndef __SASC
109 /* Can probably be changed to #if 0 -Kjetil M. (a4=globals)*/
110 GC_push_one(getreg(REG_A4));
111 # endif
112 GC_push_one(getreg(REG_A5));
113 GC_push_one(getreg(REG_A6));
114 /* Skip stack pointer */
115 GC_push_one(getreg(REG_D2));
116 GC_push_one(getreg(REG_D3));
117 GC_push_one(getreg(REG_D4));
118 GC_push_one(getreg(REG_D5));
119 GC_push_one(getreg(REG_D6));
120 GC_push_one(getreg(REG_D7));
121 # define HAVE_PUSH_REGS
122 # endif /* !__GNUC__ */
123 # endif /* AMIGA */
124
125 # if defined(M68K) && defined(MACOS)
126 # if defined(THINK_C)
127 # define PushMacReg(reg) \
128 move.l reg,(sp) \
129 jsr GC_push_one
130 asm {
131 sub.w #4,sp ; reserve space for one parameter.
132 PushMacReg(a2);
133 PushMacReg(a3);
134 PushMacReg(a4);
135 ; skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
136 PushMacReg(d2);
137 PushMacReg(d3);
138 PushMacReg(d4);
139 PushMacReg(d5);
140 PushMacReg(d6);
141 PushMacReg(d7);
142 add.w #4,sp ; fix stack.
143 }
144 # define HAVE_PUSH_REGS
145 # undef PushMacReg
146 # endif /* THINK_C */
147 # if defined(__MWERKS__)
148 PushMacRegisters();
149 # define HAVE_PUSH_REGS
150 # endif /* __MWERKS__ */
151 # endif /* MACOS */
152 }
153 #endif /* !USE_ASM_PUSH_REGS */
154
155 #if defined(HAVE_PUSH_REGS) && defined(THREADS)
156 # error GC_push_regs cannot be used with threads
157 /* Would fail for GC_do_blocking. There are probably other safety */
158 /* issues. */
159 # undef HAVE_PUSH_REGS
160 #endif
161
162 #if !defined(HAVE_PUSH_REGS) && defined(UNIX_LIKE)
163 # include <ucontext.h>
164 #endif
165
166 /* Ensure that either registers are pushed, or callee-save registers */
167 /* are somewhere on the stack, and then call fn(arg, ctxt). */
168 /* ctxt is either a pointer to a ucontext_t we generated, or NULL. */
GC_with_callee_saves_pushed(void (* fn)(ptr_t,void *),ptr_t arg)169 void GC_with_callee_saves_pushed(void (*fn)(ptr_t, void *),
170 ptr_t arg)
171 {
172 word dummy;
173 void * context = 0;
174
175 # if defined(HAVE_PUSH_REGS)
176 GC_push_regs();
177 # elif defined(UNIX_LIKE) && !defined(DARWIN) && !defined(ARM32)
178 /* Older versions of Darwin seem to lack getcontext(). */
179 /* ARM Linux often doesn't support a real getcontext(). */
180 ucontext_t ctxt;
181 if (getcontext(&ctxt) < 0)
182 ABORT ("Getcontext failed: Use another register retrieval method?");
183 context = &ctxt;
184 # if defined(SPARC) || defined(IA64)
185 /* On a register window machine, we need to save register */
186 /* contents on the stack for this to work. This may already be */
187 /* subsumed by the getcontext() call. */
188 {
189 GC_save_regs_ret_val = GC_save_regs_in_stack();
190 }
191 # endif /* register windows. */
192 # elif defined(HAVE_BUILTIN_UNWIND_INIT)
193 /* This was suggested by Richard Henderson as the way to */
194 /* force callee-save registers and register windows onto */
195 /* the stack. */
196 __builtin_unwind_init();
197 # else /* !HAVE_BUILTIN_UNWIND_INIT && !UNIX_LIKE */
198 /* && !HAVE_PUSH_REGS */
199 /* Generic code */
200 /* The idea is due to Parag Patel at HP. */
201 /* We're not sure whether he would like */
202 /* to be he acknowledged for it or not. */
203 jmp_buf regs;
204 register word * i = (word *) regs;
205 register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
206
207 /* Setjmp doesn't always clear all of the buffer. */
208 /* That tends to preserve garbage. Clear it. */
209 for (; (char *)i < lim; i++) {
210 *i = 0;
211 }
212 # if defined(MSWIN32) || defined(MSWINCE) \
213 || defined(UTS4) || defined(LINUX) || defined(EWS4800)
214 (void) setjmp(regs);
215 # else
216 (void) _setjmp(regs);
217 /* We don't want to mess with signals. According to */
218 /* SUSV3, setjmp() may or may not save signal mask. */
219 /* _setjmp won't, but is less portable. */
220 # endif
221 # endif /* !HAVE_PUSH_REGS ... */
222 fn(arg, context);
223 /* Strongly discourage the compiler from treating the above */
224 /* as a tail-call, since that would pop the register */
225 /* contents before we get a chance to look at them. */
226 GC_noop1((word)(&dummy));
227 }
228
GC_push_regs_and_stack(ptr_t cold_gc_frame)229 void GC_push_regs_and_stack(ptr_t cold_gc_frame)
230 {
231 GC_with_callee_saves_pushed(GC_push_current_stack, cold_gc_frame);
232 }
233
234 #if defined(ASM_CLEAR_CODE)
235 # ifdef LINT
236 /*ARGSUSED*/
GC_clear_stack_inner(arg,limit)237 ptr_t GC_clear_stack_inner(arg, limit)
238 ptr_t arg; word limit;
239 { return(arg); }
240 /* The real version is in a .S file */
241 # endif
242 #endif /* ASM_CLEAR_CODE */
243