[deliverable/binutils-gdb.git] / gdb / mips-sde-tdep.c

/* Target-dependent code for SDE on MIPS processors.

   Copyright (C) 2014-2019 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "osabi.h"
#include "elf-bfd.h"
#include "block.h"
#include "symtab.h"

#include "frame.h"
#include "frame-unwind.h"
#include "frame-base.h"
#include "trad-frame.h"

#include "mips-tdep.h"

/* Fill in the register cache *THIS_CACHE for THIS_FRAME for use
   in the SDE frame unwinder.  */

static struct trad_frame_cache *
mips_sde_frame_cache (struct frame_info *this_frame, void **this_cache)
{
  struct gdbarch *gdbarch = get_frame_arch (this_frame);
  const struct mips_regnum *regs = mips_regnum (gdbarch);
  const int sizeof_reg_t = mips_abi_regsize (gdbarch);
  enum mips_abi abi = mips_abi (gdbarch);
  struct trad_frame_cache *cache;
  CORE_ADDR xcpt_frame;
  CORE_ADDR start_addr;
  CORE_ADDR stack_addr;
  CORE_ADDR pc;
  int i;

  if (*this_cache != NULL)
    return (struct trad_frame_cache *) *this_cache;
  cache = trad_frame_cache_zalloc (this_frame);
  *this_cache = cache;

  /* The previous registers are held in struct xcptcontext
     which is at $sp+offs

     struct xcptcontext {
       reg_t	sr;		CP0 Status
       reg_t	cr;		CP0 Cause
       reg_t	epc;		CP0 EPC
       reg_t	vaddr;		CP0 BadVAddr
       reg_t	regs[32];	General registers
       reg_t	mdlo;		LO
       reg_t	mdhi;		HI
       reg_t	mdex;		ACX
       ...
     };
  */

  stack_addr = get_frame_register_signed (this_frame,
					  gdbarch_sp_regnum (gdbarch));
  switch (abi)
    {
    case MIPS_ABI_O32:
      /* 40: XCPTCONTEXT
	 24: xcpt_gen() argspace		(16 bytes)
	 16: _xcptcall() saved ra, rounded up	( 8 bytes)
	 00: _xcptcall() argspace 		(16 bytes)  */
      xcpt_frame = stack_addr + 40;
      break;
    case MIPS_ABI_N32:
    case MIPS_ABI_N64:
    default:			/* Wild guess.  */
      /* 16: XCPTCONTEXT
	 16: xcpt_gen() argspace 		( 0 bytes)
	 00: _xcptcall() saved ra, rounded up	(16 bytes)  */
      xcpt_frame = stack_addr + 16;
      break;
    }

  trad_frame_set_reg_addr (cache,
			   MIPS_PS_REGNUM + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 0 * sizeof_reg_t);
  trad_frame_set_reg_addr (cache,
			   regs->cause + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 1 * sizeof_reg_t);
  trad_frame_set_reg_addr (cache,
			   regs->pc + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 2 * sizeof_reg_t);
  trad_frame_set_reg_addr (cache,
			   regs->badvaddr + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 3 * sizeof_reg_t);
  for (i = 0; i < MIPS_NUMREGS; i++)
    trad_frame_set_reg_addr (cache,
			     i + MIPS_ZERO_REGNUM + gdbarch_num_regs (gdbarch),
			     xcpt_frame + (4 + i) * sizeof_reg_t);
  trad_frame_set_reg_addr (cache,
			   regs->lo + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 36 * sizeof_reg_t);
  trad_frame_set_reg_addr (cache,
			   regs->hi + gdbarch_num_regs (gdbarch),
			   xcpt_frame + 37 * sizeof_reg_t);

  pc = get_frame_pc (this_frame);
  find_pc_partial_function (pc, NULL, &start_addr, NULL);
  trad_frame_set_id (cache, frame_id_build (start_addr, stack_addr));

  return cache;
}

/* Implement the this_id function for the SDE frame unwinder.  */

static void
mips_sde_frame_this_id (struct frame_info *this_frame, void **this_cache,
			struct frame_id *this_id)
{
  struct trad_frame_cache *this_trad_cache
    = mips_sde_frame_cache (this_frame, this_cache);

  trad_frame_get_id (this_trad_cache, this_id);
}

/* Implement the prev_register function for the SDE frame unwinder.  */

static struct value *
mips_sde_frame_prev_register (struct frame_info *this_frame,
			      void **this_cache,
			      int prev_regnum)
{
  struct trad_frame_cache *trad_cache
    = mips_sde_frame_cache (this_frame, this_cache);

  return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
}

/* Implement the sniffer function for the SDE frame unwinder.  */

static int
mips_sde_frame_sniffer (const struct frame_unwind *self,
			struct frame_info *this_frame,
			void **this_cache)
{
  CORE_ADDR pc = get_frame_pc (this_frame);
  const char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);
  return (name
	  && (strcmp (name, "_xcptcall") == 0
	      || strcmp (name, "_sigtramp") == 0));
}

/* Data structure for the SDE frame unwinder.  */

static const struct frame_unwind mips_sde_frame_unwind =
{
  SIGTRAMP_FRAME,
  default_frame_unwind_stop_reason,
  mips_sde_frame_this_id,
  mips_sde_frame_prev_register,
  NULL,
  mips_sde_frame_sniffer
};

/* Implement the this_base, this_locals, and this_args hooks
   for the normal unwinder.  */

static CORE_ADDR
mips_sde_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
  struct trad_frame_cache *this_trad_cache
    = mips_sde_frame_cache (this_frame, this_cache);

  return trad_frame_get_this_base (this_trad_cache);
}

static const struct frame_base mips_sde_frame_base =
{
  &mips_sde_frame_unwind,
  mips_sde_frame_base_address,
  mips_sde_frame_base_address,
  mips_sde_frame_base_address
};

static const struct frame_base *
mips_sde_frame_base_sniffer (struct frame_info *this_frame)
{
  if (mips_sde_frame_sniffer (&mips_sde_frame_unwind, this_frame, NULL))
    return &mips_sde_frame_base;
  else
    return NULL;
}

static void
mips_sde_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect,
					   void *obj)
{
  enum gdb_osabi *os_ident_ptr = (enum gdb_osabi *) obj;
  const char *name;

  name = bfd_section_name (sect);

  /* The presence of a section with a ".sde" prefix is indicative
     of an SDE binary.  */
  if (startswith (name, ".sde"))
    *os_ident_ptr = GDB_OSABI_SDE;
}

/* OSABI sniffer for MIPS SDE.  */

static enum gdb_osabi
mips_sde_elf_osabi_sniffer (bfd *abfd)
{
  enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
  unsigned int elfosabi;

  /* If the generic sniffer gets a hit, return and let other sniffers
     get a crack at it.  */
  bfd_map_over_sections (abfd,
			 generic_elf_osabi_sniff_abi_tag_sections,
			 &osabi);
  if (osabi != GDB_OSABI_UNKNOWN)
    return GDB_OSABI_UNKNOWN;

  elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];

  if (elfosabi == ELFOSABI_NONE)
    {
      /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the
	 file are conforming to the base specification for that machine
	 (there are no OS-specific extensions).  In order to determine the
	 real OS in use we must look for OS notes that have been added.

	 For SDE, we simply look for sections named with .sde as prefixes.  */
      bfd_map_over_sections (abfd,
			     mips_sde_elf_osabi_sniff_abi_tag_sections,
			     &osabi);
    }
  return osabi;
}

static void
mips_sde_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  frame_unwind_append_unwinder (gdbarch, &mips_sde_frame_unwind);
  frame_base_append_sniffer (gdbarch, mips_sde_frame_base_sniffer);
}

void
_initialize_mips_sde_tdep (void)
{
  gdbarch_register_osabi_sniffer (bfd_arch_mips,
				  bfd_target_elf_flavour,
				  mips_sde_elf_osabi_sniffer);

  gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_SDE, mips_sde_init_abi);
}
Commit	Line	Data
bb7e3f4d YQ	1	/* Target-dependent code for SDE on MIPS processors.
bb7e3f4d YQ	2
42a4f53d	3	Copyright (C) 2014-2019 Free Software Foundation, Inc.
bb7e3f4d YQ	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	#include "defs.h"
	21	#include "osabi.h"
	22	#include "elf-bfd.h"
	23	#include "block.h"
	24	#include "symtab.h"
	25
	26	#include "frame.h"
	27	#include "frame-unwind.h"
	28	#include "frame-base.h"
	29	#include "trad-frame.h"
	30
	31	#include "mips-tdep.h"
	32
	33	/* Fill in the register cache *THIS_CACHE for THIS_FRAME for use
	34	in the SDE frame unwinder. */
	35
	36	static struct trad_frame_cache *
	37	mips_sde_frame_cache (struct frame_info this_frame, void *this_cache)
	38	{
	39	struct gdbarch *gdbarch = get_frame_arch (this_frame);
	40	const struct mips_regnum *regs = mips_regnum (gdbarch);
	41	const int sizeof_reg_t = mips_abi_regsize (gdbarch);
	42	enum mips_abi abi = mips_abi (gdbarch);
	43	struct trad_frame_cache *cache;
	44	CORE_ADDR xcpt_frame;
	45	CORE_ADDR start_addr;
	46	CORE_ADDR stack_addr;
	47	CORE_ADDR pc;
	48	int i;
	49
	50	if (*this_cache != NULL)
19ba03f4	51	return (struct trad_frame_cache ) this_cache;
bb7e3f4d YQ	52	cache = trad_frame_cache_zalloc (this_frame);
	53	*this_cache = cache;
	54
	55	/* The previous registers are held in struct xcptcontext
	56	which is at $sp+offs
	57
	58	struct xcptcontext {
	59	reg_t sr; CP0 Status
	60	reg_t cr; CP0 Cause
	61	reg_t epc; CP0 EPC
	62	reg_t vaddr; CP0 BadVAddr
	63	reg_t regs[32]; General registers
	64	reg_t mdlo; LO
	65	reg_t mdhi; HI
	66	reg_t mdex; ACX
	67	...
	68	};
	69	*/
	70
	71	stack_addr = get_frame_register_signed (this_frame,
	72	gdbarch_sp_regnum (gdbarch));
	73	switch (abi)
	74	{
	75	case MIPS_ABI_O32:
	76	/* 40: XCPTCONTEXT
	77	24: xcpt_gen() argspace (16 bytes)
	78	16: _xcptcall() saved ra, rounded up ( 8 bytes)
	79	00: _xcptcall() argspace (16 bytes) */
	80	xcpt_frame = stack_addr + 40;
	81	break;
	82	case MIPS_ABI_N32:
	83	case MIPS_ABI_N64:
	84	default: /* Wild guess. */
	85	/* 16: XCPTCONTEXT
	86	16: xcpt_gen() argspace ( 0 bytes)
	87	00: _xcptcall() saved ra, rounded up (16 bytes) */
	88	xcpt_frame = stack_addr + 16;
	89	break;
	90	}
	91
	92	trad_frame_set_reg_addr (cache,
	93	MIPS_PS_REGNUM + gdbarch_num_regs (gdbarch),
	94	xcpt_frame + 0 * sizeof_reg_t);
	95	trad_frame_set_reg_addr (cache,
	96	regs->cause + gdbarch_num_regs (gdbarch),
	97	xcpt_frame + 1 * sizeof_reg_t);
	98	trad_frame_set_reg_addr (cache,
	99	regs->pc + gdbarch_num_regs (gdbarch),
	100	xcpt_frame + 2 * sizeof_reg_t);
	101	trad_frame_set_reg_addr (cache,
	102	regs->badvaddr + gdbarch_num_regs (gdbarch),
	103	xcpt_frame + 3 * sizeof_reg_t);
	104	for (i = 0; i < MIPS_NUMREGS; i++)
	105	trad_frame_set_reg_addr (cache,
	106	i + MIPS_ZERO_REGNUM + gdbarch_num_regs (gdbarch),
	107	xcpt_frame + (4 + i) * sizeof_reg_t);
	108	trad_frame_set_reg_addr (cache,
	109	regs->lo + gdbarch_num_regs (gdbarch),
	110	xcpt_frame + 36 * sizeof_reg_t);
	111	trad_frame_set_reg_addr (cache,
	112	regs->hi + gdbarch_num_regs (gdbarch),
	113	xcpt_frame + 37 * sizeof_reg_t);
	114
	115	pc = get_frame_pc (this_frame);
116	find_pc_partial_function (pc, NULL, &start_addr, NULL);
117	trad_frame_set_id (cache, frame_id_build (start_addr, stack_addr));
118
119	return cache;
120	}
121
122	/* Implement the this_id function for the SDE frame unwinder. */
123
124	static void
125	mips_sde_frame_this_id (struct frame_info this_frame, void *this_cache,
126	struct frame_id *this_id)
127	{
128	struct trad_frame_cache *this_trad_cache
129	= mips_sde_frame_cache (this_frame, this_cache);
130
131	trad_frame_get_id (this_trad_cache, this_id);
132	}
133
134	/* Implement the prev_register function for the SDE frame unwinder. */
135
136	static struct value *
137	mips_sde_frame_prev_register (struct frame_info *this_frame,
138	void **this_cache,
139	int prev_regnum)
140	{
141	struct trad_frame_cache *trad_cache
142	= mips_sde_frame_cache (this_frame, this_cache);
143
144	return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
145	}
146
147	/* Implement the sniffer function for the SDE frame unwinder. */
148
149	static int
150	mips_sde_frame_sniffer (const struct frame_unwind *self,
151	struct frame_info *this_frame,
152	void **this_cache)
153	{
154	CORE_ADDR pc = get_frame_pc (this_frame);
155	const char *name;
156
157	find_pc_partial_function (pc, &name, NULL, NULL);
158	return (name
159	&& (strcmp (name, "_xcptcall") == 0
160	\|\| strcmp (name, "_sigtramp") == 0));
161	}
162
163	/* Data structure for the SDE frame unwinder. */
164
165	static const struct frame_unwind mips_sde_frame_unwind =
166	{
167	SIGTRAMP_FRAME,
168	default_frame_unwind_stop_reason,
169	mips_sde_frame_this_id,
170	mips_sde_frame_prev_register,
171	NULL,
172	mips_sde_frame_sniffer
173	};
174
175	/* Implement the this_base, this_locals, and this_args hooks
176	for the normal unwinder. */
177
178	static CORE_ADDR
179	mips_sde_frame_base_address (struct frame_info this_frame, void *this_cache)
180	{
181	struct trad_frame_cache *this_trad_cache
182	= mips_sde_frame_cache (this_frame, this_cache);
183
184	return trad_frame_get_this_base (this_trad_cache);
185	}
186
187	static const struct frame_base mips_sde_frame_base =
188	{
189	&mips_sde_frame_unwind,
190	mips_sde_frame_base_address,
191	mips_sde_frame_base_address,
192	mips_sde_frame_base_address
193	};
194
195	static const struct frame_base *
196	mips_sde_frame_base_sniffer (struct frame_info *this_frame)
197	{
198	if (mips_sde_frame_sniffer (&mips_sde_frame_unwind, this_frame, NULL))
199	return &mips_sde_frame_base;
200	else
201	return NULL;
202	}
203
204	static void
205	mips_sde_elf_osabi_sniff_abi_tag_sections (bfd abfd, asection sect,
206	void *obj)
207	{
19ba03f4	208	enum gdb_osabi os_ident_ptr = (enum gdb_osabi ) obj;
bb7e3f4d YQ	209	const char *name;
bb7e3f4d YQ	210
fd361982	211	name = bfd_section_name (sect);
bb7e3f4d YQ	212
	213	/* The presence of a section with a ".sde" prefix is indicative
	214	of an SDE binary. */
61012eef	215	if (startswith (name, ".sde"))
bb7e3f4d YQ	216	*os_ident_ptr = GDB_OSABI_SDE;
	217	}
	218
	219	/* OSABI sniffer for MIPS SDE. */
	220
	221	static enum gdb_osabi
	222	mips_sde_elf_osabi_sniffer (bfd *abfd)
	223	{
	224	enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
	225	unsigned int elfosabi;
	226
	227	/* If the generic sniffer gets a hit, return and let other sniffers
	228	get a crack at it. */
	229	bfd_map_over_sections (abfd,
	230	generic_elf_osabi_sniff_abi_tag_sections,
	231	&osabi);
	232	if (osabi != GDB_OSABI_UNKNOWN)
	233	return GDB_OSABI_UNKNOWN;
	234
	235	elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
	236
	237	if (elfosabi == ELFOSABI_NONE)
	238	{
	239	/* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the
	240	file are conforming to the base specification for that machine
	241	(there are no OS-specific extensions). In order to determine the
	242	real OS in use we must look for OS notes that have been added.
	243
	244	For SDE, we simply look for sections named with .sde as prefixes. */
	245	bfd_map_over_sections (abfd,
	246	mips_sde_elf_osabi_sniff_abi_tag_sections,
	247	&osabi);
	248	}
	249	return osabi;
	250	}
	251
	252	static void
	253	mips_sde_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	254	{
	255	frame_unwind_append_unwinder (gdbarch, &mips_sde_frame_unwind);
	256	frame_base_append_sniffer (gdbarch, mips_sde_frame_base_sniffer);
	257	}
	258
bb7e3f4d YQ	259	void
	260	_initialize_mips_sde_tdep (void)
	261	{
	262	gdbarch_register_osabi_sniffer (bfd_arch_mips,
	263	bfd_target_elf_flavour,
	264	mips_sde_elf_osabi_sniffer);
	265
	266	gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_SDE, mips_sde_init_abi);
	267	}