source: trunk/libs/newlib/src/include/gdb/callback.h @ 521

Last change on this file since 521 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 11.6 KB
Line 
1/* Remote target system call callback support.
2   Copyright 1997-2013 Free Software Foundation, Inc.
3   Contributed by Cygnus Solutions.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20/* This interface isn't intended to be specific to any particular kind
21   of remote (hardware, simulator, whatever).  As such, support for it
22   (e.g. sim/common/callback.c) should *not* live in the simulator source
23   tree, nor should it live in the gdb source tree.  */
24
25/* There are various ways to handle system calls:
26
27   1) Have a simulator intercept the appropriate trap instruction and
28   directly perform the system call on behalf of the target program.
29   This is the typical way of handling system calls for embedded targets.
30   [Handling system calls for embedded targets isn't that much of an
31   oxymoron as running compiler testsuites make use of the capability.]
32
33   This method of system call handling is done when STATE_ENVIRONMENT
34   is ENVIRONMENT_USER.
35
36   2) Have a simulator emulate the hardware as much as possible.
37   If the program running on the real hardware communicates with some sort
38   of target manager, one would want to be able to run this program on the
39   simulator as well.
40
41   This method of system call handling is done when STATE_ENVIRONMENT
42   is ENVIRONMENT_OPERATING.
43*/
44
45#ifndef CALLBACK_H
46#define CALLBACK_H
47
48/* ??? The reason why we check for va_start here should be documented.  */
49
50#ifndef va_start
51#include <ansidecl.h>
52#include <stdarg.h>
53#endif
54/* Needed for enum bfd_endian.  */
55#include "bfd.h"
56
57/* Mapping of host/target values.  */
58/* ??? For debugging purposes, one might want to add a string of the
59   name of the symbol.  */
60
61typedef struct {
62  int host_val;
63  int target_val;
64} CB_TARGET_DEFS_MAP;
65
66#define MAX_CALLBACK_FDS 10
67
68/* Forward decl for stat/fstat.  */
69struct stat;
70
71typedef struct host_callback_struct host_callback;
72
73struct host_callback_struct
74{
75  int (*close) (host_callback *,int);
76  int (*get_errno) (host_callback *);
77  int (*isatty) (host_callback *, int);
78  int (*lseek) (host_callback *, int, long , int);
79  int (*open) (host_callback *, const char*, int mode);
80  int (*read) (host_callback *,int,  char *, int);
81  int (*read_stdin) ( host_callback *, char *, int);
82  int (*rename) (host_callback *, const char *, const char *);
83  int (*system) (host_callback *, const char *);
84  long (*time) (host_callback *, long *);
85  int (*unlink) (host_callback *, const char *);
86  int (*write) (host_callback *,int, const char *, int);
87  int (*write_stdout) (host_callback *, const char *, int);
88  void (*flush_stdout) (host_callback *);
89  int (*write_stderr) (host_callback *, const char *, int);
90  void (*flush_stderr) (host_callback *);
91  int (*stat) (host_callback *, const char *, struct stat *);
92  int (*fstat) (host_callback *, int, struct stat *);
93  int (*lstat) (host_callback *, const char *, struct stat *);
94  int (*ftruncate) (host_callback *, int, long);
95  int (*truncate) (host_callback *, const char *, long);
96  int (*pipe) (host_callback *, int *);
97
98  /* Called by the framework when a read call has emptied a pipe buffer.  */
99  void (*pipe_empty) (host_callback *, int read_fd, int write_fd);
100
101  /* Called by the framework when a write call makes a pipe buffer
102     non-empty.  */
103  void (*pipe_nonempty) (host_callback *, int read_fd, int write_fd);
104
105  /* When present, call to the client to give it the oportunity to
106     poll any io devices for a request to quit (indicated by a nonzero
107     return value). */
108  int (*poll_quit) (host_callback *);
109
110  /* Used when the target has gone away, so we can close open
111     handles and free memory etc etc.  */
112  int (*shutdown) (host_callback *);
113  int (*init)     (host_callback *);
114
115  /* depreciated, use vprintf_filtered - Talk to the user on a console.  */
116  void (*printf_filtered) (host_callback *, const char *, ...);
117
118  /* Talk to the user on a console.  */
119  void (*vprintf_filtered) (host_callback *, const char *, va_list);
120
121  /* Same as vprintf_filtered but to stderr.  */
122  void (*evprintf_filtered) (host_callback *, const char *, va_list);
123
124  /* Print an error message and "exit".
125     In the case of gdb "exiting" means doing a longjmp back to the main
126     command loop.  */
127  void (*error) (host_callback *, const char *, ...)
128#ifdef __GNUC__
129    __attribute__ ((__noreturn__))
130#endif
131    ;
132
133  int last_errno;               /* host format */
134
135  int fdmap[MAX_CALLBACK_FDS];
136  /* fd_buddy is used to contruct circular lists of target fds that point to
137     the same host fd.  A uniquely mapped fd points to itself; for a closed
138     one, fd_buddy has the value -1.  The host file descriptors for stdin /
139     stdout / stderr are never closed by the simulators, so they are put
140     in a special fd_buddy circular list which also has MAX_CALLBACK_FDS
141     as a member.  */
142  /* ??? We don't have a callback entry for dup, although it is trival to
143     implement now.  */
144  short fd_buddy[MAX_CALLBACK_FDS+1];
145
146  /* 0 = none, >0 = reader (index of writer),
147     <0 = writer (negative index of reader).
148     If abs (ispipe[N]) == N, then N is an end of a pipe whose other
149     end is closed.  */
150  short ispipe[MAX_CALLBACK_FDS];
151
152  /* A writer stores the buffer at its index.  Consecutive writes
153     realloc the buffer and add to the size.  The reader indicates the
154     read part in its .size, until it has consumed it all, at which
155     point it deallocates the buffer and zeroes out both sizes.  */
156  struct pipe_write_buffer
157  {
158    int size;
159    char *buffer;
160  } pipe_buffer[MAX_CALLBACK_FDS];
161
162  /* System call numbers.  */
163  CB_TARGET_DEFS_MAP *syscall_map;
164  /* Errno values.  */
165  CB_TARGET_DEFS_MAP *errno_map;
166  /* Flags to the open system call.  */
167  CB_TARGET_DEFS_MAP *open_map;
168  /* Signal numbers.  */
169  CB_TARGET_DEFS_MAP *signal_map;
170  /* Layout of `stat' struct.
171     The format is a series of "name,length" pairs separated by colons.
172     Empty space is indicated with a `name' of "space".
173     All padding must be explicitly mentioned.
174     Lengths are in bytes.  If this needs to be extended to bits,
175     use "name.bits".
176     Example: "st_dev,4:st_ino,4:st_mode,4:..."  */
177  const char *stat_map;
178
179  enum bfd_endian target_endian;
180
181  /* Size of an "int" on the target (for syscalls whose ABI uses "int").
182     This must include padding, and only padding-at-higher-address is
183     supported.  For example, a 64-bit target with 32-bit int:s which
184     are padded to 64 bits when in an array, should supposedly set this
185     to 8.  The default is 4 which matches ILP32 targets and 64-bit
186     targets with 32-bit ints and no padding.  */
187  int target_sizeof_int;
188
189  /* Marker for those wanting to do sanity checks.
190     This should remain the last member of this struct to help catch
191     miscompilation errors. */
192#define HOST_CALLBACK_MAGIC 4705 /* teds constant */
193  int magic;
194};
195
196extern host_callback default_callback;
197
198/* Canonical versions of system call numbers.
199   It's not intended to willy-nilly throw every system call ever heard
200   of in here.  Only include those that have an important use.
201   ??? One can certainly start a discussion over the ones that are currently
202   here, but that will always be true.  */
203
204/* These are used by the ANSI C support of libc.  */
205#define CB_SYS_exit     1
206#define CB_SYS_open     2
207#define CB_SYS_close    3
208#define CB_SYS_read     4
209#define CB_SYS_write    5
210#define CB_SYS_lseek    6
211#define CB_SYS_unlink   7
212#define CB_SYS_getpid   8
213#define CB_SYS_kill     9
214#define CB_SYS_fstat    10
215/*#define CB_SYS_sbrk   11 - not currently a system call, but reserved.  */
216
217/* ARGV support.  */
218#define CB_SYS_argvlen  12
219#define CB_SYS_argv     13
220
221/* These are extras added for one reason or another.  */
222#define CB_SYS_chdir    14
223#define CB_SYS_stat     15
224#define CB_SYS_chmod    16
225#define CB_SYS_utime    17
226#define CB_SYS_time     18
227
228/* More standard syscalls.  */
229#define CB_SYS_lstat    19
230#define CB_SYS_rename   20
231#define CB_SYS_truncate 21
232#define CB_SYS_ftruncate 22
233#define CB_SYS_pipe     23
234
235/* New ARGV support.  */
236#define CB_SYS_argc     24
237#define CB_SYS_argnlen  25
238#define CB_SYS_argn     26
239
240/* Struct use to pass and return information necessary to perform a
241   system call.  */
242/* FIXME: Need to consider target word size.  */
243
244typedef struct cb_syscall {
245  /* The target's value of what system call to perform.  */
246  int func;
247  /* The arguments to the syscall.  */
248  long arg1, arg2, arg3, arg4;
249
250  /* The result.  */
251  long result;
252  /* Some system calls have two results.  */
253  long result2;
254  /* The target's errno value, or 0 if success.
255     This is converted to the target's value with host_to_target_errno.  */
256  int errcode;
257
258  /* Working space to be used by memory read/write callbacks.  */
259  PTR p1;
260  PTR p2;
261  long x1,x2;
262
263  /* Callbacks for reading/writing memory (e.g. for read/write syscalls).
264     ??? long or unsigned long might be better to use for the `count'
265     argument here.  We mimic sim_{read,write} for now.  Be careful to
266     test any changes with -Wall -Werror, mixed signed comparisons
267     will get you.  */
268  int (*read_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/,
269                   unsigned long /*taddr*/, char * /*buf*/,
270                   int /*bytes*/);
271  int (*write_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/,
272                    unsigned long /*taddr*/, const char * /*buf*/,
273                    int /*bytes*/);
274
275  /* For sanity checking, should be last entry.  */
276  int magic;
277} CB_SYSCALL;
278
279/* Magic number sanity checker.  */
280#define CB_SYSCALL_MAGIC 0x12344321
281
282/* Macro to initialize CB_SYSCALL.  Called first, before filling in
283   any fields.  */
284#define CB_SYSCALL_INIT(sc) \
285do { \
286  memset ((sc), 0, sizeof (*(sc))); \
287  (sc)->magic = CB_SYSCALL_MAGIC; \
288} while (0)
289
290/* Return codes for various interface routines.  */
291
292typedef enum {
293  CB_RC_OK = 0,
294  /* generic error */
295  CB_RC_ERR,
296  /* either file not found or no read access */
297  CB_RC_ACCESS,
298  CB_RC_NO_MEM
299} CB_RC;
300
301/* Read in target values for system call numbers, errno values, signals.  */
302CB_RC cb_read_target_syscall_maps (host_callback *, const char *);
303
304/* Translate target to host syscall function numbers.  */
305int cb_target_to_host_syscall (host_callback *, int);
306
307/* Translate host to target errno value.  */
308int cb_host_to_target_errno (host_callback *, int);
309
310/* Translate target to host open flags.  */
311int cb_target_to_host_open (host_callback *, int);
312
313/* Translate target signal number to host.  */
314int cb_target_to_host_signal (host_callback *, int);
315
316/* Translate host signal number to target.  */
317int cb_host_to_gdb_signal (host_callback *, int);
318
319/* Translate host stat struct to target.
320   If stat struct ptr is NULL, just compute target stat struct size.
321   Result is size of target stat struct or 0 if error.  */
322int cb_host_to_target_stat (host_callback *, const struct stat *, PTR);
323
324/* Translate a value to target endian.  */
325void cb_store_target_endian (host_callback *, char *, int, long);
326
327/* Tests for special fds.  */
328int cb_is_stdin (host_callback *, int);
329int cb_is_stdout (host_callback *, int);
330int cb_is_stderr (host_callback *, int);
331
332/* Read a string out of the target.  */
333int cb_get_string (host_callback *, CB_SYSCALL *, char *, int, unsigned long);
334
335/* Perform a system call.  */
336CB_RC cb_syscall (host_callback *, CB_SYSCALL *);
337
338#endif
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