--- /dev/null
+/* Renesas M32C target-dependent code for GDB, the GNU debugger.
+
+ Copyright 2004, 2005 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 2 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, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "defs.h"
+
+#include <stdarg.h>
+
+#if defined (HAVE_STRING_H)
+#include <string.h>
+#endif
+
+#include "gdb_assert.h"
+#include "elf-bfd.h"
+#include "elf/m32c.h"
+#include "gdb/sim-m32c.h"
+#include "dis-asm.h"
+#include "gdbtypes.h"
+#include "regcache.h"
+#include "arch-utils.h"
+#include "frame.h"
+#include "frame-unwind.h"
+#include "dwarf2-frame.h"
+#include "dwarf2expr.h"
+#include "symtab.h"
+#include "gdbcore.h"
+#include "value.h"
+#include "reggroups.h"
+#include "prologue-value.h"
+#include "target.h"
+
+\f
+/* The m32c tdep structure. */
+
+static struct reggroup *m32c_dma_reggroup;
+
+struct m32c_reg;
+
+/* The type of a function that moves the value of REG between CACHE or
+ BUF --- in either direction. */
+typedef void (m32c_move_reg_t) (struct m32c_reg *reg,
+ struct regcache *cache,
+ void *buf);
+
+struct m32c_reg
+{
+ /* The name of this register. */
+ const char *name;
+
+ /* Its type. */
+ struct type *type;
+
+ /* The architecture this register belongs to. */
+ struct gdbarch *arch;
+
+ /* Its GDB register number. */
+ int num;
+
+ /* Its sim register number. */
+ int sim_num;
+
+ /* Its DWARF register number, or -1 if it doesn't have one. */
+ int dwarf_num;
+
+ /* Register group memberships. */
+ unsigned int general_p : 1;
+ unsigned int dma_p : 1;
+ unsigned int system_p : 1;
+ unsigned int save_restore_p : 1;
+
+ /* Functions to read its value from a regcache, and write its value
+ to a regcache. */
+ m32c_move_reg_t *read, *write;
+
+ /* Data for READ and WRITE functions. The exact meaning depends on
+ the specific functions selected; see the comments for those
+ functions. */
+ struct m32c_reg *rx, *ry;
+ int n;
+};
+
+
+/* An overestimate of the number of raw and pseudoregisters we will
+ have. The exact answer depends on the variant of the architecture
+ at hand, but we can use this to declare statically allocated
+ arrays, and bump it up when needed. */
+#define M32C_MAX_NUM_REGS (75)
+
+/* The largest assigned DWARF register number. */
+#define M32C_MAX_DWARF_REGNUM (40)
+
+
+struct gdbarch_tdep
+{
+ /* All the registers for this variant, indexed by GDB register
+ number, and the number of registers present. */
+ struct m32c_reg regs[M32C_MAX_NUM_REGS];
+
+ /* The number of valid registers. */
+ int num_regs;
+
+ /* Interesting registers. These are pointers into REGS. */
+ struct m32c_reg *pc, *flg;
+ struct m32c_reg *r0, *r1, *r2, *r3, *a0, *a1;
+ struct m32c_reg *r2r0, *r3r2r1r0, *r3r1r2r0;
+ struct m32c_reg *sb, *fb, *sp;
+
+ /* A table indexed by DWARF register numbers, pointing into
+ REGS. */
+ struct m32c_reg *dwarf_regs[M32C_MAX_DWARF_REGNUM + 1];
+
+ /* Types for this architecture. We can't use the builtin_type_foo
+ types, because they're not initialized when building a gdbarch
+ structure. */
+ struct type *voyd, *ptr_voyd, *func_voyd;
+ struct type *uint8, *uint16;
+ struct type *int8, *int16, *int32, *int64;
+
+ /* The types for data address and code address registers. */
+ struct type *data_addr_reg_type, *code_addr_reg_type;
+
+ /* The number of bytes a return address pushed by a 'jsr' instruction
+ occupies on the stack. */
+ int ret_addr_bytes;
+
+ /* The number of bytes an address register occupies on the stack
+ when saved by an 'enter' or 'pushm' instruction. */
+ int push_addr_bytes;
+};
+
+\f
+/* Types. */
+
+static void
+make_types (struct gdbarch *arch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ unsigned long mach = gdbarch_bfd_arch_info (arch)->mach;
+ int data_addr_reg_bits, code_addr_reg_bits;
+ char type_name[50];
+
+#if 0
+ /* This is used to clip CORE_ADDR values, so this value is
+ appropriate both on the m32c, where pointers are 32 bits long,
+ and on the m16c, where pointers are sixteen bits long, but there
+ may be code above the 64k boundary. */
+ set_gdbarch_addr_bit (arch, 24);
+#else
+ /* GCC uses 32 bits for addrs in the dwarf info, even though
+ only 16/24 bits are used. Setting addr_bit to 24 causes
+ errors in reading the dwarf addresses. */
+ set_gdbarch_addr_bit (arch, 32);
+#endif
+
+ set_gdbarch_int_bit (arch, 16);
+ switch (mach)
+ {
+ case bfd_mach_m16c:
+ data_addr_reg_bits = 16;
+ code_addr_reg_bits = 24;
+ set_gdbarch_ptr_bit (arch, 16);
+ tdep->ret_addr_bytes = 3;
+ tdep->push_addr_bytes = 2;
+ break;
+
+ case bfd_mach_m32c:
+ data_addr_reg_bits = 24;
+ code_addr_reg_bits = 24;
+ set_gdbarch_ptr_bit (arch, 32);
+ tdep->ret_addr_bytes = 4;
+ tdep->push_addr_bytes = 4;
+ break;
+
+ default:
+ gdb_assert (0);
+ }
+
+ /* The builtin_type_mumble variables are sometimes uninitialized when
+ this is called, so we avoid using them. */
+ tdep->voyd = init_type (TYPE_CODE_VOID, 1, 0, "void", NULL);
+ tdep->ptr_voyd = init_type (TYPE_CODE_PTR, gdbarch_ptr_bit (arch) / 8,
+ TYPE_FLAG_UNSIGNED, NULL, NULL);
+ TYPE_TARGET_TYPE (tdep->ptr_voyd) = tdep->voyd;
+ tdep->func_voyd = lookup_function_type (tdep->voyd);
+
+ sprintf (type_name, "%s_data_addr_t",
+ gdbarch_bfd_arch_info (arch)->printable_name);
+ tdep->data_addr_reg_type
+ = init_type (TYPE_CODE_PTR, data_addr_reg_bits / 8,
+ TYPE_FLAG_UNSIGNED, xstrdup (type_name), NULL);
+ TYPE_TARGET_TYPE (tdep->data_addr_reg_type) = tdep->voyd;
+
+ sprintf (type_name, "%s_code_addr_t",
+ gdbarch_bfd_arch_info (arch)->printable_name);
+ tdep->code_addr_reg_type
+ = init_type (TYPE_CODE_PTR, code_addr_reg_bits / 8,
+ TYPE_FLAG_UNSIGNED, xstrdup (type_name), NULL);
+ TYPE_TARGET_TYPE (tdep->code_addr_reg_type) = tdep->func_voyd;
+
+ tdep->uint8 = init_type (TYPE_CODE_INT, 1, TYPE_FLAG_UNSIGNED,
+ "uint8_t", NULL);
+ tdep->uint16 = init_type (TYPE_CODE_INT, 2, TYPE_FLAG_UNSIGNED,
+ "uint16_t", NULL);
+ tdep->int8 = init_type (TYPE_CODE_INT, 1, 0, "int8_t", NULL);
+ tdep->int16 = init_type (TYPE_CODE_INT, 2, 0, "int16_t", NULL);
+ tdep->int32 = init_type (TYPE_CODE_INT, 4, 0, "int32_t", NULL);
+ tdep->int64 = init_type (TYPE_CODE_INT, 8, 0, "int64_t", NULL);
+}
+
+
+\f
+/* Register set. */
+
+static const char *
+m32c_register_name (int num)
+{
+ return gdbarch_tdep (current_gdbarch)->regs[num].name;
+}
+
+
+static struct type *
+m32c_register_type (struct gdbarch *arch, int reg_nr)
+{
+ return gdbarch_tdep (arch)->regs[reg_nr].type;
+}
+
+
+static int
+m32c_register_sim_regno (int reg_nr)
+{
+ return gdbarch_tdep (current_gdbarch)->regs[reg_nr].sim_num;
+}
+
+
+static int
+m32c_debug_info_reg_to_regnum (int reg_nr)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ if (0 <= reg_nr && reg_nr <= M32C_MAX_DWARF_REGNUM
+ && tdep->dwarf_regs[reg_nr])
+ return tdep->dwarf_regs[reg_nr]->num;
+ else
+ /* The DWARF CFI code expects to see -1 for invalid register
+ numbers. */
+ return -1;
+}
+
+
+int
+m32c_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
+ struct reggroup *group)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ struct m32c_reg *reg = &tdep->regs[regnum];
+
+ /* The anonymous raw registers aren't in any groups. */
+ if (! reg->name)
+ return 0;
+
+ if (group == all_reggroup)
+ return 1;
+
+ if (group == general_reggroup
+ && reg->general_p)
+ return 1;
+
+ if (group == m32c_dma_reggroup
+ && reg->dma_p)
+ return 1;
+
+ if (group == system_reggroup
+ && reg->system_p)
+ return 1;
+
+ /* Since the m32c DWARF register numbers refer to cooked registers, not
+ raw registers, and frame_pop depends on the save and restore groups
+ containing registers the DWARF CFI will actually mention, our save
+ and restore groups are cooked registers, not raw registers. (This is
+ why we can't use the default reggroup function.) */
+ if ((group == save_reggroup
+ || group == restore_reggroup)
+ && reg->save_restore_p)
+ return 1;
+
+ return 0;
+}
+
+
+/* Register move functions. We declare them here using
+ m32c_move_reg_t to check the types. */
+static m32c_move_reg_t m32c_raw_read, m32c_raw_write;
+static m32c_move_reg_t m32c_banked_read, m32c_banked_write;
+static m32c_move_reg_t m32c_sb_read, m32c_sb_write;
+static m32c_move_reg_t m32c_part_read, m32c_part_write;
+static m32c_move_reg_t m32c_cat_read, m32c_cat_write;
+static m32c_move_reg_t m32c_r3r2r1r0_read, m32c_r3r2r1r0_write;
+
+
+/* Copy the value of the raw register REG from CACHE to BUF. */
+static void
+m32c_raw_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ regcache_raw_read (cache, reg->num, buf);
+}
+
+
+/* Copy the value of the raw register REG from BUF to CACHE. */
+static void
+m32c_raw_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ regcache_raw_write (cache, reg->num, (const void *) buf);
+}
+
+
+/* Return the value of the 'flg' register in CACHE. */
+static int
+m32c_read_flg (struct regcache *cache)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (cache));
+ ULONGEST flg;
+ regcache_raw_read_unsigned (cache, tdep->flg->num, &flg);
+ return flg & 0xffff;
+}
+
+
+/* Move the value of a banked register from CACHE to BUF.
+ If the value of the 'flg' register in CACHE has any of the bits
+ masked in REG->n set, then read REG->ry. Otherwise, read
+ REG->rx. */
+static void
+m32c_banked_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ struct m32c_reg *bank_reg
+ = ((m32c_read_flg (cache) & reg->n) ? reg->ry : reg->rx);
+ regcache_raw_read (cache, bank_reg->num, buf);
+}
+
+
+/* Move the value of a banked register from BUF to CACHE.
+ If the value of the 'flg' register in CACHE has any of the bits
+ masked in REG->n set, then write REG->ry. Otherwise, write
+ REG->rx. */
+static void
+m32c_banked_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ struct m32c_reg *bank_reg
+ = ((m32c_read_flg (cache) & reg->n) ? reg->ry : reg->rx);
+ regcache_raw_write (cache, bank_reg->num, (const void *) buf);
+}
+
+
+/* Move the value of SB from CACHE to BUF. On bfd_mach_m32c, SB is a
+ banked register; on bfd_mach_m16c, it's not. */
+static void
+m32c_sb_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ if (gdbarch_bfd_arch_info (reg->arch)->mach == bfd_mach_m16c)
+ m32c_raw_read (reg->rx, cache, buf);
+ else
+ m32c_banked_read (reg, cache, buf);
+}
+
+
+/* Move the value of SB from BUF to CACHE. On bfd_mach_m32c, SB is a
+ banked register; on bfd_mach_m16c, it's not. */
+static void
+m32c_sb_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ if (gdbarch_bfd_arch_info (reg->arch)->mach == bfd_mach_m16c)
+ m32c_raw_write (reg->rx, cache, buf);
+ else
+ m32c_banked_write (reg, cache, buf);
+}
+
+
+/* Assuming REG uses m32c_part_read and m32c_part_write, set *OFFSET_P
+ and *LEN_P to the offset and length, in bytes, of the part REG
+ occupies in its underlying register. The offset is from the
+ lower-addressed end, regardless of the architecture's endianness.
+ (The M32C family is always little-endian, but let's keep those
+ assumptions out of here.) */
+static void
+m32c_find_part (struct m32c_reg *reg, int *offset_p, int *len_p)
+{
+ /* The length of the containing register, of which REG is one part. */
+ int containing_len = TYPE_LENGTH (reg->rx->type);
+
+ /* The length of one "element" in our imaginary array. */
+ int elt_len = TYPE_LENGTH (reg->type);
+
+ /* The offset of REG's "element" from the least significant end of
+ the containing register. */
+ int elt_offset = reg->n * elt_len;
+
+ /* If we extend off the end, trim the length of the element. */
+ if (elt_offset + elt_len > containing_len)
+ {
+ elt_len = containing_len - elt_offset;
+ /* We shouldn't be declaring partial registers that go off the
+ end of their containing registers. */
+ gdb_assert (elt_len > 0);
+ }
+
+ /* Flip the offset around if we're big-endian. */
+ if (gdbarch_byte_order (reg->arch) == BFD_ENDIAN_BIG)
+ elt_offset = TYPE_LENGTH (reg->rx->type) - elt_offset - elt_len;
+
+ *offset_p = elt_offset;
+ *len_p = elt_len;
+}
+
+
+/* Move the value of a partial register (r0h, intbl, etc.) from CACHE
+ to BUF. Treating the value of the register REG->rx as an array of
+ REG->type values, where higher indices refer to more significant
+ bits, read the value of the REG->n'th element. */
+static void
+m32c_part_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ int offset, len;
+ memset (buf, 0, TYPE_LENGTH (reg->type));
+ m32c_find_part (reg, &offset, &len);
+ regcache_cooked_read_part (cache, reg->rx->num, offset, len, buf);
+}
+
+
+/* Move the value of a banked register from BUF to CACHE.
+ Treating the value of the register REG->rx as an array of REG->type
+ values, where higher indices refer to more significant bits, write
+ the value of the REG->n'th element. */
+static void
+m32c_part_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ int offset, len;
+ m32c_find_part (reg, &offset, &len);
+ regcache_cooked_write_part (cache, reg->rx->num, offset, len, buf);
+}
+
+
+/* Move the value of REG from CACHE to BUF. REG's value is the
+ concatenation of the values of the registers REG->rx and REG->ry,
+ with REG->rx contributing the more significant bits. */
+static void
+m32c_cat_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ int high_bytes = TYPE_LENGTH (reg->rx->type);
+ int low_bytes = TYPE_LENGTH (reg->ry->type);
+ /* For address arithmetic. */
+ unsigned char *cbuf = buf;
+
+ gdb_assert (TYPE_LENGTH (reg->type) == high_bytes + low_bytes);
+
+ if (gdbarch_byte_order (reg->arch) == BFD_ENDIAN_BIG)
+ {
+ regcache_cooked_read (cache, reg->rx->num, cbuf);
+ regcache_cooked_read (cache, reg->ry->num, cbuf + high_bytes);
+ }
+ else
+ {
+ regcache_cooked_read (cache, reg->rx->num, cbuf + low_bytes);
+ regcache_cooked_read (cache, reg->ry->num, cbuf);
+ }
+}
+
+
+/* Move the value of REG from CACHE to BUF. REG's value is the
+ concatenation of the values of the registers REG->rx and REG->ry,
+ with REG->rx contributing the more significant bits. */
+static void
+m32c_cat_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ int high_bytes = TYPE_LENGTH (reg->rx->type);
+ int low_bytes = TYPE_LENGTH (reg->ry->type);
+ /* For address arithmetic. */
+ unsigned char *cbuf = buf;
+
+ gdb_assert (TYPE_LENGTH (reg->type) == high_bytes + low_bytes);
+
+ if (gdbarch_byte_order (reg->arch) == BFD_ENDIAN_BIG)
+ {
+ regcache_cooked_write (cache, reg->rx->num, cbuf);
+ regcache_cooked_write (cache, reg->ry->num, cbuf + high_bytes);
+ }
+ else
+ {
+ regcache_cooked_write (cache, reg->rx->num, cbuf + low_bytes);
+ regcache_cooked_write (cache, reg->ry->num, cbuf);
+ }
+}
+
+
+/* Copy the value of the raw register REG from CACHE to BUF. REG is
+ the concatenation (from most significant to least) of r3, r2, r1,
+ and r0. */
+static void
+m32c_r3r2r1r0_read (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (reg->arch);
+ int len = TYPE_LENGTH (tdep->r0->type);
+
+ /* For address arithmetic. */
+ unsigned char *cbuf = buf;
+
+ if (gdbarch_byte_order (reg->arch) == BFD_ENDIAN_BIG)
+ {
+ regcache_cooked_read (cache, tdep->r0->num, cbuf + len * 3);
+ regcache_cooked_read (cache, tdep->r1->num, cbuf + len * 2);
+ regcache_cooked_read (cache, tdep->r2->num, cbuf + len * 1);
+ regcache_cooked_read (cache, tdep->r3->num, cbuf);
+ }
+ else
+ {
+ regcache_cooked_read (cache, tdep->r0->num, cbuf);
+ regcache_cooked_read (cache, tdep->r1->num, cbuf + len * 1);
+ regcache_cooked_read (cache, tdep->r2->num, cbuf + len * 2);
+ regcache_cooked_read (cache, tdep->r3->num, cbuf + len * 3);
+ }
+}
+
+
+/* Copy the value of the raw register REG from BUF to CACHE. REG is
+ the concatenation (from most significant to least) of r3, r2, r1,
+ and r0. */
+static void
+m32c_r3r2r1r0_write (struct m32c_reg *reg, struct regcache *cache, void *buf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (reg->arch);
+ int len = TYPE_LENGTH (tdep->r0->type);
+
+ /* For address arithmetic. */
+ unsigned char *cbuf = buf;
+
+ if (gdbarch_byte_order (reg->arch) == BFD_ENDIAN_BIG)
+ {
+ regcache_cooked_write (cache, tdep->r0->num, cbuf + len * 3);
+ regcache_cooked_write (cache, tdep->r1->num, cbuf + len * 2);
+ regcache_cooked_write (cache, tdep->r2->num, cbuf + len * 1);
+ regcache_cooked_write (cache, tdep->r3->num, cbuf);
+ }
+ else
+ {
+ regcache_cooked_write (cache, tdep->r0->num, cbuf);
+ regcache_cooked_write (cache, tdep->r1->num, cbuf + len * 1);
+ regcache_cooked_write (cache, tdep->r2->num, cbuf + len * 2);
+ regcache_cooked_write (cache, tdep->r3->num, cbuf + len * 3);
+ }
+}
+
+
+static void
+m32c_pseudo_register_read (struct gdbarch *arch,
+ struct regcache *cache,
+ int cookednum,
+ gdb_byte *buf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ struct m32c_reg *reg;
+
+ gdb_assert (0 <= cookednum && cookednum < tdep->num_regs);
+ gdb_assert (arch == get_regcache_arch (cache));
+ gdb_assert (arch == tdep->regs[cookednum].arch);
+ reg = &tdep->regs[cookednum];
+
+ reg->read (reg, cache, buf);
+}
+
+
+static void
+m32c_pseudo_register_write (struct gdbarch *arch,
+ struct regcache *cache,
+ int cookednum,
+ const gdb_byte *buf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ struct m32c_reg *reg;
+
+ gdb_assert (0 <= cookednum && cookednum < tdep->num_regs);
+ gdb_assert (arch == get_regcache_arch (cache));
+ gdb_assert (arch == tdep->regs[cookednum].arch);
+ reg = &tdep->regs[cookednum];
+
+ reg->write (reg, cache, (void *) buf);
+}
+
+
+/* Add a register with the given fields to the end of ARCH's table.
+ Return a pointer to the newly added register. */
+static struct m32c_reg *
+add_reg (struct gdbarch *arch,
+ const char *name,
+ struct type *type,
+ int sim_num,
+ m32c_move_reg_t *read,
+ m32c_move_reg_t *write,
+ struct m32c_reg *rx,
+ struct m32c_reg *ry,
+ int n)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ struct m32c_reg *r = &tdep->regs[tdep->num_regs];
+
+ gdb_assert (tdep->num_regs < M32C_MAX_NUM_REGS);
+
+ r->name = name;
+ r->type = type;
+ r->arch = arch;
+ r->num = tdep->num_regs;
+ r->sim_num = sim_num;
+ r->dwarf_num = -1;
+ r->general_p = 0;
+ r->dma_p = 0;
+ r->system_p = 0;
+ r->save_restore_p = 0;
+ r->read = read;
+ r->write = write;
+ r->rx = rx;
+ r->ry = ry;
+ r->n = n;
+
+ tdep->num_regs++;
+
+ return r;
+}
+
+
+/* Record NUM as REG's DWARF register number. */
+static void
+set_dwarf_regnum (struct m32c_reg *reg, int num)
+{
+ gdb_assert (num < M32C_MAX_NUM_REGS);
+
+ /* Update the reg->DWARF mapping. Only count the first number
+ assigned to this register. */
+ if (reg->dwarf_num == -1)
+ reg->dwarf_num = num;
+
+ /* Update the DWARF->reg mapping. */
+ gdbarch_tdep (reg->arch)->dwarf_regs[num] = reg;
+}
+
+
+/* Mark REG as a general-purpose register, and return it. */
+static struct m32c_reg *
+mark_general (struct m32c_reg *reg)
+{
+ reg->general_p = 1;
+ return reg;
+}
+
+
+/* Mark REG as a DMA register, and return it. */
+static struct m32c_reg *
+mark_dma (struct m32c_reg *reg)
+{
+ reg->dma_p = 1;
+ return reg;
+}
+
+
+/* Mark REG as a SYSTEM register, and return it. */
+static struct m32c_reg *
+mark_system (struct m32c_reg *reg)
+{
+ reg->system_p = 1;
+ return reg;
+}
+
+
+/* Mark REG as a save-restore register, and return it. */
+static struct m32c_reg *
+mark_save_restore (struct m32c_reg *reg)
+{
+ reg->save_restore_p = 1;
+ return reg;
+}
+
+
+#define FLAGBIT_B 0x0010
+#define FLAGBIT_U 0x0080
+
+/* Handy macros for declaring registers. These all evaluate to
+ pointers to the register declared. Macros that define two
+ registers evaluate to a pointer to the first. */
+
+/* A raw register named NAME, with type TYPE and sim number SIM_NUM. */
+#define R(name, type, sim_num) \
+ (add_reg (arch, (name), (type), (sim_num), \
+ m32c_raw_read, m32c_raw_write, NULL, NULL, 0))
+
+/* The simulator register number for a raw register named NAME. */
+#define SIM(name) (m32c_sim_reg_ ## name)
+
+/* A raw unsigned 16-bit data register named NAME.
+ NAME should be an identifier, not a string. */
+#define R16U(name) \
+ (R(#name, tdep->uint16, SIM (name)))
+
+/* A raw data address register named NAME.
+ NAME should be an identifier, not a string. */
+#define RA(name) \
+ (R(#name, tdep->data_addr_reg_type, SIM (name)))
+
+/* A raw code address register named NAME. NAME should
+ be an identifier, not a string. */
+#define RC(name) \
+ (R(#name, tdep->code_addr_reg_type, SIM (name)))
+
+/* A pair of raw registers named NAME0 and NAME1, with type TYPE.
+ NAME should be an identifier, not a string. */
+#define RP(name, type) \
+ (R(#name "0", (type), SIM (name ## 0)), \
+ R(#name "1", (type), SIM (name ## 1)) - 1)
+
+/* A raw banked general-purpose data register named NAME.
+ NAME should be an identifier, not a string. */
+#define RBD(name) \
+ (R(NULL, tdep->int16, SIM (name ## _bank0)), \
+ R(NULL, tdep->int16, SIM (name ## _bank1)) - 1)
+
+/* A raw banked data address register named NAME.
+ NAME should be an identifier, not a string. */
+#define RBA(name) \
+ (R(NULL, tdep->data_addr_reg_type, SIM (name ## _bank0)), \
+ R(NULL, tdep->data_addr_reg_type, SIM (name ## _bank1)) - 1)
+
+/* A cooked register named NAME referring to a raw banked register
+ from the bank selected by the current value of FLG. RAW_PAIR
+ should be a pointer to the first register in the banked pair.
+ NAME must be an identifier, not a string. */
+#define CB(name, raw_pair) \
+ (add_reg (arch, #name, (raw_pair)->type, 0, \
+ m32c_banked_read, m32c_banked_write, \
+ (raw_pair), (raw_pair + 1), FLAGBIT_B))
+
+/* A pair of registers named NAMEH and NAMEL, of type TYPE, that
+ access the top and bottom halves of the register pointed to by
+ NAME. NAME should be an identifier. */
+#define CHL(name, type) \
+ (add_reg (arch, #name "h", (type), 0, \
+ m32c_part_read, m32c_part_write, name, NULL, 1), \
+ add_reg (arch, #name "l", (type), 0, \
+ m32c_part_read, m32c_part_write, name, NULL, 0) - 1)
+
+/* A register constructed by concatenating the two registers HIGH and
+ LOW, whose name is HIGHLOW and whose type is TYPE. */
+#define CCAT(high, low, type) \
+ (add_reg (arch, #high #low, (type), 0, \
+ m32c_cat_read, m32c_cat_write, (high), (low), 0))
+
+/* Abbreviations for marking register group membership. */
+#define G(reg) (mark_general (reg))
+#define S(reg) (mark_system (reg))
+#define DMA(reg) (mark_dma (reg))
+
+
+/* Construct the register set for ARCH. */
+static void
+make_regs (struct gdbarch *arch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ int mach = gdbarch_bfd_arch_info (arch)->mach;
+
+ struct m32c_reg *raw_r0_pair = RBD (r0);
+ struct m32c_reg *raw_r1_pair = RBD (r1);
+ struct m32c_reg *raw_r2_pair = RBD (r2);
+ struct m32c_reg *raw_r3_pair = RBD (r3);
+ struct m32c_reg *raw_a0_pair = RBA (a0);
+ struct m32c_reg *raw_a1_pair = RBA (a1);
+ struct m32c_reg *raw_fb_pair = RBA (fb);
+
+ /* sb is banked on the bfd_mach_m32c, but not on bfd_mach_m16c.
+ We always declare both raw registers, and deal with the distinction
+ in the pseudoregister. */
+ struct m32c_reg *raw_sb_pair = RBA (sb);
+
+ struct m32c_reg *usp = S (RA (usp));
+ struct m32c_reg *isp = S (RA (isp));
+ struct m32c_reg *intb = S (RC (intb));
+ struct m32c_reg *pc = G (RC (pc));
+ struct m32c_reg *flg = G (R16U (flg));
+
+ if (mach == bfd_mach_m32c)
+ {
+ struct m32c_reg *svf = S (R16U (svf));
+ struct m32c_reg *svp = S (RC (svp));
+ struct m32c_reg *vct = S (RC (vct));
+
+ struct m32c_reg *dmd01 = DMA (RP (dmd, tdep->uint8));
+ struct m32c_reg *dct01 = DMA (RP (dct, tdep->uint16));
+ struct m32c_reg *drc01 = DMA (RP (drc, tdep->uint16));
+ struct m32c_reg *dma01 = DMA (RP (dma, tdep->data_addr_reg_type));
+ struct m32c_reg *dsa01 = DMA (RP (dsa, tdep->data_addr_reg_type));
+ struct m32c_reg *dra01 = DMA (RP (dra, tdep->data_addr_reg_type));
+ }
+
+ int num_raw_regs = tdep->num_regs;
+
+ struct m32c_reg *r0 = G (CB (r0, raw_r0_pair));
+ struct m32c_reg *r1 = G (CB (r1, raw_r1_pair));
+ struct m32c_reg *r2 = G (CB (r2, raw_r2_pair));
+ struct m32c_reg *r3 = G (CB (r3, raw_r3_pair));
+ struct m32c_reg *a0 = G (CB (a0, raw_a0_pair));
+ struct m32c_reg *a1 = G (CB (a1, raw_a1_pair));
+ struct m32c_reg *fb = G (CB (fb, raw_fb_pair));
+
+ /* sb is banked on the bfd_mach_m32c, but not on bfd_mach_m16c.
+ Specify custom read/write functions that do the right thing. */
+ struct m32c_reg *sb
+ = G (add_reg (arch, "sb", raw_sb_pair->type, 0,
+ m32c_sb_read, m32c_sb_write,
+ raw_sb_pair, raw_sb_pair + 1, 0));
+
+ /* The current sp is either usp or isp, depending on the value of
+ the FLG register's U bit. */
+ struct m32c_reg *sp
+ = G (add_reg (arch, "sp", usp->type, 0,
+ m32c_banked_read, m32c_banked_write, isp, usp, FLAGBIT_U));
+
+ struct m32c_reg *r0hl = CHL (r0, tdep->int8);
+ struct m32c_reg *r1hl = CHL (r1, tdep->int8);
+ struct m32c_reg *r2hl = CHL (r2, tdep->int8);
+ struct m32c_reg *r3hl = CHL (r3, tdep->int8);
+ struct m32c_reg *intbhl = CHL (intb, tdep->int16);
+
+ struct m32c_reg *r2r0 = CCAT (r2, r0, tdep->int32);
+ struct m32c_reg *r3r1 = CCAT (r3, r1, tdep->int32);
+ struct m32c_reg *r3r1r2r0 = CCAT (r3r1, r2r0, tdep->int64);
+
+ struct m32c_reg *r3r2r1r0
+ = add_reg (arch, "r3r2r1r0", tdep->int64, 0,
+ m32c_r3r2r1r0_read, m32c_r3r2r1r0_write, NULL, NULL, 0);
+
+ struct m32c_reg *a1a0;
+ if (mach == bfd_mach_m16c)
+ a1a0 = CCAT (a1, a0, tdep->int32);
+ else
+ a1a0 = NULL;
+
+ int num_cooked_regs = tdep->num_regs - num_raw_regs;
+
+ tdep->pc = pc;
+ tdep->flg = flg;
+ tdep->r0 = r0;
+ tdep->r1 = r1;
+ tdep->r2 = r2;
+ tdep->r3 = r3;
+ tdep->r2r0 = r2r0;
+ tdep->r3r2r1r0 = r3r2r1r0;
+ tdep->r3r1r2r0 = r3r1r2r0;
+ tdep->a0 = a0;
+ tdep->a1 = a1;
+ tdep->sb = sb;
+ tdep->fb = fb;
+ tdep->sp = sp;
+
+ /* Set up the DWARF register table. */
+ memset (tdep->dwarf_regs, 0, sizeof (tdep->dwarf_regs));
+ set_dwarf_regnum (r0hl + 1, 0x01);
+ set_dwarf_regnum (r0hl + 0, 0x02);
+ set_dwarf_regnum (r1hl + 1, 0x03);
+ set_dwarf_regnum (r1hl + 0, 0x04);
+ set_dwarf_regnum (r0, 0x05);
+ set_dwarf_regnum (r1, 0x06);
+ set_dwarf_regnum (r2, 0x07);
+ set_dwarf_regnum (r3, 0x08);
+ set_dwarf_regnum (a0, 0x09);
+ set_dwarf_regnum (a1, 0x0a);
+ set_dwarf_regnum (fb, 0x0b);
+ set_dwarf_regnum (sp, 0x0c);
+ set_dwarf_regnum (pc, 0x0d); /* GCC's invention */
+ set_dwarf_regnum (sb, 0x13);
+ set_dwarf_regnum (r2r0, 0x15);
+ set_dwarf_regnum (r3r1, 0x16);
+ if (a1a0)
+ set_dwarf_regnum (a1a0, 0x17);
+
+ /* Enumerate the save/restore register group.
+
+ The regcache_save and regcache_restore functions apply their read
+ function to each register in this group.
+
+ Since frame_pop supplies frame_unwind_register as its read
+ function, the registers meaningful to the Dwarf unwinder need to
+ be in this group.
+
+ On the other hand, when we make inferior calls, save_inferior_status
+ and restore_inferior_status use them to preserve the current register
+ values across the inferior call. For this, you'd kind of like to
+ preserve all the raw registers, to protect the interrupted code from
+ any sort of bank switching the callee might have done. But we handle
+ those cases so badly anyway --- for example, it matters whether we
+ restore FLG before or after we restore the general-purpose registers,
+ but there's no way to express that --- that it isn't worth worrying
+ about.
+
+ We omit control registers like inthl: if you call a function that
+ changes those, it's probably because you wanted that change to be
+ visible to the interrupted code. */
+ mark_save_restore (r0);
+ mark_save_restore (r1);
+ mark_save_restore (r2);
+ mark_save_restore (r3);
+ mark_save_restore (a0);
+ mark_save_restore (a1);
+ mark_save_restore (sb);
+ mark_save_restore (fb);
+ mark_save_restore (sp);
+ mark_save_restore (pc);
+ mark_save_restore (flg);
+
+ set_gdbarch_num_regs (arch, num_raw_regs);
+ set_gdbarch_num_pseudo_regs (arch, num_cooked_regs);
+ set_gdbarch_pc_regnum (arch, pc->num);
+ set_gdbarch_sp_regnum (arch, sp->num);
+ set_gdbarch_register_name (arch, m32c_register_name);
+ set_gdbarch_register_type (arch, m32c_register_type);
+ set_gdbarch_pseudo_register_read (arch, m32c_pseudo_register_read);
+ set_gdbarch_pseudo_register_write (arch, m32c_pseudo_register_write);
+ set_gdbarch_register_sim_regno (arch, m32c_register_sim_regno);
+ set_gdbarch_stab_reg_to_regnum (arch, m32c_debug_info_reg_to_regnum);
+ set_gdbarch_dwarf_reg_to_regnum (arch, m32c_debug_info_reg_to_regnum);
+ set_gdbarch_dwarf2_reg_to_regnum (arch, m32c_debug_info_reg_to_regnum);
+ set_gdbarch_register_reggroup_p (arch, m32c_register_reggroup_p);
+
+ reggroup_add (arch, general_reggroup);
+ reggroup_add (arch, all_reggroup);
+ reggroup_add (arch, save_reggroup);
+ reggroup_add (arch, restore_reggroup);
+ reggroup_add (arch, system_reggroup);
+ reggroup_add (arch, m32c_dma_reggroup);
+}
+
+
+\f
+/* Breakpoints. */
+
+static const unsigned char *
+m32c_breakpoint_from_pc (CORE_ADDR *pc, int *len)
+{
+ static unsigned char break_insn[] = { 0x00 }; /* brk */
+
+ *len = sizeof (break_insn);
+ return break_insn;
+}
+
+
+\f
+/* Prologue analysis. */
+
+struct m32c_prologue
+{
+ /* For consistency with the DWARF 2 .debug_frame info generated by
+ GCC, a frame's CFA is the address immediately after the saved
+ return address. */
+
+ /* The architecture for which we generated this prologue info. */
+ struct gdbarch *arch;
+
+ enum {
+ /* This function uses a frame pointer. */
+ prologue_with_frame_ptr,
+
+ /* This function has no frame pointer. */
+ prologue_sans_frame_ptr,
+
+ /* This function sets up the stack, so its frame is the first
+ frame on the stack. */
+ prologue_first_frame
+
+ } kind;
+
+ /* If KIND is prologue_with_frame_ptr, this is the offset from the
+ CFA to where the frame pointer points. This is always zero or
+ negative. */
+ LONGEST frame_ptr_offset;
+
+ /* If KIND is prologue_sans_frame_ptr, the offset from the CFA to
+ the stack pointer --- always zero or negative.
+
+ Calling this a "size" is a bit misleading, but given that the
+ stack grows downwards, using offsets for everything keeps one
+ from going completely sign-crazy: you never change anything's
+ sign for an ADD instruction; always change the second operand's
+ sign for a SUB instruction; and everything takes care of
+ itself.
+
+ Functions that use alloca don't have a constant frame size. But
+ they always have frame pointers, so we must use that to find the
+ CFA (and perhaps to unwind the stack pointer). */
+ LONGEST frame_size;
+
+ /* The address of the first instruction at which the frame has been
+ set up and the arguments are where the debug info says they are
+ --- as best as we can tell. */
+ CORE_ADDR prologue_end;
+
+ /* reg_offset[R] is the offset from the CFA at which register R is
+ saved, or 1 if register R has not been saved. (Real values are
+ always zero or negative.) */
+ LONGEST reg_offset[M32C_MAX_NUM_REGS];
+};
+
+
+/* The longest I've seen, anyway. */
+#define M32C_MAX_INSN_LEN (9)
+
+/* Processor state, for the prologue analyzer. */
+struct m32c_pv_state
+{
+ struct gdbarch *arch;
+ pv_t r0, r1, r2, r3;
+ pv_t a0, a1;
+ pv_t sb, fb, sp;
+ pv_t pc;
+ struct pv_area *stack;
+
+ /* Bytes from the current PC, the address they were read from,
+ and the address of the next unconsumed byte. */
+ gdb_byte insn[M32C_MAX_INSN_LEN];
+ CORE_ADDR scan_pc, next_addr;
+};
+
+
+/* Push VALUE on STATE's stack, occupying SIZE bytes. Return zero if
+ all went well, or non-zero if simulating the action would trash our
+ state. */
+static int
+m32c_pv_push (struct m32c_pv_state *state, pv_t value, int size)
+{
+ if (pv_area_store_would_trash (state->stack, state->sp))
+ return 1;
+
+ state->sp = pv_add_constant (state->sp, -size);
+ pv_area_store (state->stack, state->sp, size, value);
+
+ return 0;
+}
+
+
+/* A source or destination location for an m16c or m32c
+ instruction. */
+struct srcdest
+{
+ /* If srcdest_reg, the location is a register pointed to by REG.
+ If srcdest_partial_reg, the location is part of a register pointed
+ to by REG. We don't try to handle this too well.
+ If srcdest_mem, the location is memory whose address is ADDR. */
+ enum { srcdest_reg, srcdest_partial_reg, srcdest_mem } kind;
+ pv_t *reg, addr;
+};
+
+
+/* Return the SIZE-byte value at LOC in STATE. */
+static pv_t
+m32c_srcdest_fetch (struct m32c_pv_state *state, struct srcdest loc, int size)
+{
+ if (loc.kind == srcdest_mem)
+ return pv_area_fetch (state->stack, loc.addr, size);
+ else if (loc.kind == srcdest_partial_reg)
+ return pv_unknown ();
+ else
+ return *loc.reg;
+}
+
+
+/* Write VALUE, a SIZE-byte value, to LOC in STATE. Return zero if
+ all went well, or non-zero if simulating the store would trash our
+ state. */
+static int
+m32c_srcdest_store (struct m32c_pv_state *state, struct srcdest loc,
+ pv_t value, int size)
+{
+ if (loc.kind == srcdest_mem)
+ {
+ if (pv_area_store_would_trash (state->stack, loc.addr))
+ return 1;
+ pv_area_store (state->stack, loc.addr, size, value);
+ }
+ else if (loc.kind == srcdest_partial_reg)
+ *loc.reg = pv_unknown ();
+ else
+ *loc.reg = value;
+
+ return 0;
+}
+
+
+static int
+m32c_sign_ext (int v, int bits)
+{
+ int mask = 1 << (bits - 1);
+ return (v ^ mask) - mask;
+}
+
+static unsigned int
+m32c_next_byte (struct m32c_pv_state *st)
+{
+ gdb_assert (st->next_addr - st->scan_pc < sizeof (st->insn));
+ return st->insn[st->next_addr++ - st->scan_pc];
+}
+
+static int
+m32c_udisp8 (struct m32c_pv_state *st)
+{
+ return m32c_next_byte (st);
+}
+
+
+static int
+m32c_sdisp8 (struct m32c_pv_state *st)
+{
+ return m32c_sign_ext (m32c_next_byte (st), 8);
+}
+
+
+static int
+m32c_udisp16 (struct m32c_pv_state *st)
+{
+ int low = m32c_next_byte (st);
+ int high = m32c_next_byte (st);
+
+ return low + (high << 8);
+}
+
+
+static int
+m32c_sdisp16 (struct m32c_pv_state *st)
+{
+ int low = m32c_next_byte (st);
+ int high = m32c_next_byte (st);
+
+ return m32c_sign_ext (low + (high << 8), 16);
+}
+
+
+static int
+m32c_udisp24 (struct m32c_pv_state *st)
+{
+ int low = m32c_next_byte (st);
+ int mid = m32c_next_byte (st);
+ int high = m32c_next_byte (st);
+
+ return low + (mid << 8) + (high << 16);
+}
+
+
+/* Extract the 'source' field from an m32c MOV.size:G-format instruction. */
+static int
+m32c_get_src23 (unsigned char *i)
+{
+ return (((i[0] & 0x70) >> 2)
+ | ((i[1] & 0x30) >> 4));
+}
+
+
+/* Extract the 'dest' field from an m32c MOV.size:G-format instruction. */
+static int
+m32c_get_dest23 (unsigned char *i)
+{
+ return (((i[0] & 0x0e) << 1)
+ | ((i[1] & 0xc0) >> 6));
+}
+
+
+static struct srcdest
+m32c_decode_srcdest4 (struct m32c_pv_state *st,
+ int code, int size)
+{
+ struct srcdest sd;
+
+ if (code < 6)
+ sd.kind = (size == 2 ? srcdest_reg : srcdest_partial_reg);
+ else
+ sd.kind = srcdest_mem;
+
+ switch (code)
+ {
+ case 0x0: sd.reg = (size == 1 ? &st->r0 : &st->r0); break;
+ case 0x1: sd.reg = (size == 1 ? &st->r0 : &st->r1); break;
+ case 0x2: sd.reg = (size == 1 ? &st->r1 : &st->r2); break;
+ case 0x3: sd.reg = (size == 1 ? &st->r1 : &st->r3); break;
+
+ case 0x4: sd.reg = &st->a0; break;
+ case 0x5: sd.reg = &st->a1; break;
+
+ case 0x6: sd.addr = st->a0; break;
+ case 0x7: sd.addr = st->a1; break;
+
+ case 0x8: sd.addr = pv_add_constant (st->a0, m32c_udisp8 (st)); break;
+ case 0x9: sd.addr = pv_add_constant (st->a1, m32c_udisp8 (st)); break;
+ case 0xa: sd.addr = pv_add_constant (st->sb, m32c_udisp8 (st)); break;
+ case 0xb: sd.addr = pv_add_constant (st->fb, m32c_sdisp8 (st)); break;
+
+ case 0xc: sd.addr = pv_add_constant (st->a0, m32c_udisp16 (st)); break;
+ case 0xd: sd.addr = pv_add_constant (st->a1, m32c_udisp16 (st)); break;
+ case 0xe: sd.addr = pv_add_constant (st->sb, m32c_udisp16 (st)); break;
+ case 0xf: sd.addr = pv_constant (m32c_udisp16 (st)); break;
+
+ default:
+ gdb_assert (0);
+ }
+
+ return sd;
+}
+
+
+static struct srcdest
+m32c_decode_sd23 (struct m32c_pv_state *st, int code, int size, int ind)
+{
+ struct srcdest sd;
+
+ switch (code)
+ {
+ case 0x12:
+ case 0x13:
+ case 0x10:
+ case 0x11:
+ sd.kind = (size == 1) ? srcdest_partial_reg : srcdest_reg;
+ break;
+
+ case 0x02:
+ case 0x03:
+ sd.kind = (size == 4) ? srcdest_reg : srcdest_partial_reg;
+ break;
+
+ default:
+ sd.kind = srcdest_mem;
+ break;
+
+ }
+
+ switch (code)
+ {
+ case 0x12: sd.reg = &st->r0; break;
+ case 0x13: sd.reg = &st->r1; break;
+ case 0x10: sd.reg = ((size == 1) ? &st->r0 : &st->r2); break;
+ case 0x11: sd.reg = ((size == 1) ? &st->r1 : &st->r3); break;
+ case 0x02: sd.reg = &st->a0; break;
+ case 0x03: sd.reg = &st->a1; break;
+
+ case 0x00: sd.addr = st->a0; break;
+ case 0x01: sd.addr = st->a1; break;
+ case 0x04: sd.addr = pv_add_constant (st->a0, m32c_udisp8 (st)); break;
+ case 0x05: sd.addr = pv_add_constant (st->a1, m32c_udisp8 (st)); break;
+ case 0x06: sd.addr = pv_add_constant (st->sb, m32c_udisp8 (st)); break;
+ case 0x07: sd.addr = pv_add_constant (st->fb, m32c_sdisp8 (st)); break;
+ case 0x08: sd.addr = pv_add_constant (st->a0, m32c_udisp16 (st)); break;
+ case 0x09: sd.addr = pv_add_constant (st->a1, m32c_udisp16 (st)); break;
+ case 0x0a: sd.addr = pv_add_constant (st->sb, m32c_udisp16 (st)); break;
+ case 0x0b: sd.addr = pv_add_constant (st->fb, m32c_sdisp16 (st)); break;
+ case 0x0c: sd.addr = pv_add_constant (st->a0, m32c_udisp24 (st)); break;
+ case 0x0d: sd.addr = pv_add_constant (st->a1, m32c_udisp24 (st)); break;
+ case 0x0f: sd.addr = pv_constant (m32c_udisp16 (st)); break;
+ case 0x0e: sd.addr = pv_constant (m32c_udisp24 (st)); break;
+ default:
+ gdb_assert (0);
+ }
+
+ if (ind)
+ {
+ sd.addr = m32c_srcdest_fetch (st, sd, 4);
+ sd.kind = srcdest_mem;
+ }
+
+ return sd;
+}
+
+
+/* The r16c and r32c machines have instructions with similar
+ semantics, but completely different machine language encodings. So
+ we break out the semantics into their own functions, and leave
+ machine-specific decoding in m32c_analyze_prologue.
+
+ The following functions all expect their arguments already decoded,
+ and they all return zero if analysis should continue past this
+ instruction, or non-zero if analysis should stop. */
+
+
+/* Simulate an 'enter SIZE' instruction in STATE. */
+static int
+m32c_pv_enter (struct m32c_pv_state *state, int size)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (state->arch);
+
+ /* If simulating this store would require us to forget
+ everything we know about the stack frame in the name of
+ accuracy, it would be better to just quit now. */
+ if (pv_area_store_would_trash (state->stack, state->sp))
+ return 1;
+
+ if (m32c_pv_push (state, state->fb, tdep->push_addr_bytes))
+ return 1;
+ state->fb = state->sp;
+ state->sp = pv_add_constant (state->sp, -size);
+
+ return 0;
+}
+
+
+static int
+m32c_pv_pushm_one (struct m32c_pv_state *state, pv_t reg,
+ int bit, int src, int size)
+{
+ if (bit & src)
+ {
+ if (m32c_pv_push (state, reg, size))
+ return 1;
+ }
+
+ return 0;
+}
+
+
+/* Simulate a 'pushm SRC' instruction in STATE. */
+static int
+m32c_pv_pushm (struct m32c_pv_state *state, int src)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (state->arch);
+
+ /* The bits in SRC indicating which registers to save are:
+ r0 r1 r2 r3 a0 a1 sb fb */
+ return
+ ( m32c_pv_pushm_one (state, state->fb, 0x01, src, tdep->push_addr_bytes)
+ || m32c_pv_pushm_one (state, state->sb, 0x02, src, tdep->push_addr_bytes)
+ || m32c_pv_pushm_one (state, state->a1, 0x04, src, tdep->push_addr_bytes)
+ || m32c_pv_pushm_one (state, state->a0, 0x08, src, tdep->push_addr_bytes)
+ || m32c_pv_pushm_one (state, state->r3, 0x10, src, 2)
+ || m32c_pv_pushm_one (state, state->r2, 0x20, src, 2)
+ || m32c_pv_pushm_one (state, state->r1, 0x40, src, 2)
+ || m32c_pv_pushm_one (state, state->r0, 0x80, src, 2));
+}
+
+/* Return non-zero if VALUE is the first incoming argument register. */
+
+static int
+m32c_is_1st_arg_reg (struct m32c_pv_state *state, pv_t value)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (state->arch);
+ return (value.kind == pvk_register
+ && (gdbarch_bfd_arch_info (state->arch)->mach == bfd_mach_m16c
+ ? (value.reg == tdep->r1->num)
+ : (value.reg == tdep->r0->num))
+ && value.k == 0);
+}
+
+/* Return non-zero if VALUE is an incoming argument register. */
+
+static int
+m32c_is_arg_reg (struct m32c_pv_state *state, pv_t value)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (state->arch);
+ return (value.kind == pvk_register
+ && (gdbarch_bfd_arch_info (state->arch)->mach == bfd_mach_m16c
+ ? (value.reg == tdep->r1->num || value.reg == tdep->r2->num)
+ : (value.reg == tdep->r0->num))
+ && value.k == 0);
+}
+
+/* Return non-zero if a store of VALUE to LOC is probably spilling an
+ argument register to its stack slot in STATE. Such instructions
+ should be included in the prologue, if possible.
+
+ The store is a spill if:
+ - the value being stored is the original value of an argument register;
+ - the value has not already been stored somewhere in STACK; and
+ - LOC is a stack slot (e.g., a memory location whose address is
+ relative to the original value of the SP). */
+
+static int
+m32c_is_arg_spill (struct m32c_pv_state *st,
+ struct srcdest loc,
+ pv_t value)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (st->arch);
+
+ return (m32c_is_arg_reg (st, value)
+ && loc.kind == srcdest_mem
+ && pv_is_register (loc.addr, tdep->sp->num)
+ && ! pv_area_find_reg (st->stack, st->arch, value.reg, 0));
+}
+
+/* Return non-zero if a store of VALUE to LOC is probably
+ copying the struct return address into an address register
+ for immediate use. This is basically a "spill" into the
+ address register, instead of onto the stack.
+
+ The prerequisites are:
+ - value being stored is original value of the FIRST arg register;
+ - value has not already been stored on stack; and
+ - LOC is an address register (a0 or a1). */
+
+static int
+m32c_is_struct_return (struct m32c_pv_state *st,
+ struct srcdest loc,
+ pv_t value)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (st->arch);
+
+ return (m32c_is_1st_arg_reg (st, value)
+ && !pv_area_find_reg (st->stack, st->arch, value.reg, 0)
+ && loc.kind == srcdest_reg
+ && (pv_is_register (*loc.reg, tdep->a0->num)
+ || pv_is_register (*loc.reg, tdep->a1->num)));
+}
+
+/* Return non-zero if a 'pushm' saving the registers indicated by SRC
+ was a register save:
+ - all the named registers should have their original values, and
+ - the stack pointer should be at a constant offset from the
+ original stack pointer. */
+static int
+m32c_pushm_is_reg_save (struct m32c_pv_state *st, int src)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (st->arch);
+ /* The bits in SRC indicating which registers to save are:
+ r0 r1 r2 r3 a0 a1 sb fb */
+ return
+ (pv_is_register (st->sp, tdep->sp->num)
+ && (! (src & 0x01) || pv_is_register_k (st->fb, tdep->fb->num, 0))
+ && (! (src & 0x02) || pv_is_register_k (st->sb, tdep->sb->num, 0))
+ && (! (src & 0x04) || pv_is_register_k (st->a1, tdep->a1->num, 0))
+ && (! (src & 0x08) || pv_is_register_k (st->a0, tdep->a0->num, 0))
+ && (! (src & 0x10) || pv_is_register_k (st->r3, tdep->r3->num, 0))
+ && (! (src & 0x20) || pv_is_register_k (st->r2, tdep->r2->num, 0))
+ && (! (src & 0x40) || pv_is_register_k (st->r1, tdep->r1->num, 0))
+ && (! (src & 0x80) || pv_is_register_k (st->r0, tdep->r0->num, 0)));
+}
+
+
+/* Function for finding saved registers in a 'struct pv_area'; we pass
+ this to pv_area_scan.
+
+ If VALUE is a saved register, ADDR says it was saved at a constant
+ offset from the frame base, and SIZE indicates that the whole
+ register was saved, record its offset in RESULT_UNTYPED. */
+static void
+check_for_saved (void *prologue_untyped, pv_t addr, CORE_ADDR size, pv_t value)
+{
+ struct m32c_prologue *prologue = (struct m32c_prologue *) prologue_untyped;
+ struct gdbarch *arch = prologue->arch;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+
+ /* Is this the unchanged value of some register being saved on the
+ stack? */
+ if (value.kind == pvk_register
+ && value.k == 0
+ && pv_is_register (addr, tdep->sp->num))
+ {
+ /* Some registers require special handling: they're saved as a
+ larger value than the register itself. */
+ CORE_ADDR saved_size = register_size (arch, value.reg);
+
+ if (value.reg == tdep->pc->num)
+ saved_size = tdep->ret_addr_bytes;
+ else if (gdbarch_register_type (arch, value.reg)
+ == tdep->data_addr_reg_type)
+ saved_size = tdep->push_addr_bytes;
+
+ if (size == saved_size)
+ {
+ /* Find which end of the saved value corresponds to our
+ register. */
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG)
+ prologue->reg_offset[value.reg]
+ = (addr.k + saved_size - register_size (arch, value.reg));
+ else
+ prologue->reg_offset[value.reg] = addr.k;
+ }
+ }
+}
+
+
+/* Analyze the function prologue for ARCH at START, going no further
+ than LIMIT, and place a description of what we found in
+ PROLOGUE. */
+void
+m32c_analyze_prologue (struct gdbarch *arch,
+ CORE_ADDR start, CORE_ADDR limit,
+ struct m32c_prologue *prologue)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ unsigned long mach = gdbarch_bfd_arch_info (arch)->mach;
+ CORE_ADDR after_last_frame_related_insn;
+ struct cleanup *back_to;
+ struct m32c_pv_state st;
+
+ st.arch = arch;
+ st.r0 = pv_register (tdep->r0->num, 0);
+ st.r1 = pv_register (tdep->r1->num, 0);
+ st.r2 = pv_register (tdep->r2->num, 0);
+ st.r3 = pv_register (tdep->r3->num, 0);
+ st.a0 = pv_register (tdep->a0->num, 0);
+ st.a1 = pv_register (tdep->a1->num, 0);
+ st.sb = pv_register (tdep->sb->num, 0);
+ st.fb = pv_register (tdep->fb->num, 0);
+ st.sp = pv_register (tdep->sp->num, 0);
+ st.pc = pv_register (tdep->pc->num, 0);
+ st.stack = make_pv_area (tdep->sp->num);
+ back_to = make_cleanup_free_pv_area (st.stack);
+
+ /* Record that the call instruction has saved the return address on
+ the stack. */
+ m32c_pv_push (&st, st.pc, tdep->ret_addr_bytes);
+
+ memset (prologue, 0, sizeof (*prologue));
+ prologue->arch = arch;
+ {
+ int i;
+ for (i = 0; i < M32C_MAX_NUM_REGS; i++)
+ prologue->reg_offset[i] = 1;
+ }
+
+ st.scan_pc = after_last_frame_related_insn = start;
+
+ while (st.scan_pc < limit)
+ {
+ pv_t pre_insn_fb = st.fb;
+ pv_t pre_insn_sp = st.sp;
+
+ /* In theory we could get in trouble by trying to read ahead
+ here, when we only know we're expecting one byte. In
+ practice I doubt anyone will care, and it makes the rest of
+ the code easier. */
+ if (target_read_memory (st.scan_pc, st.insn, sizeof (st.insn)))
+ /* If we can't fetch the instruction from memory, stop here
+ and hope for the best. */
+ break;
+ st.next_addr = st.scan_pc;
+
+ /* The assembly instructions are written as they appear in the
+ section of the processor manuals that describe the
+ instruction encodings.
+
+ When a single assembly language instruction has several
+ different machine-language encodings, the manual
+ distinguishes them by a number in parens, before the
+ mnemonic. Those numbers are included, as well.
+
+ The srcdest decoding instructions have the same names as the
+ analogous functions in the simulator. */
+ if (mach == bfd_mach_m16c)
+ {
+ /* (1) ENTER #imm8 */
+ if (st.insn[0] == 0x7c && st.insn[1] == 0xf2)
+ {
+ if (m32c_pv_enter (&st, st.insn[2]))
+ break;
+ st.next_addr += 3;
+ }
+ /* (1) PUSHM src */
+ else if (st.insn[0] == 0xec)
+ {
+ int src = st.insn[1];
+ if (m32c_pv_pushm (&st, src))
+ break;
+ st.next_addr += 2;
+
+ if (m32c_pushm_is_reg_save (&st, src))
+ after_last_frame_related_insn = st.next_addr;
+ }
+
+ /* (6) MOV.size:G src, dest */
+ else if ((st.insn[0] & 0xfe) == 0x72)
+ {
+ int size = (st.insn[0] & 0x01) ? 2 : 1;
+
+ st.next_addr += 2;
+
+ struct srcdest src
+ = m32c_decode_srcdest4 (&st, (st.insn[1] >> 4) & 0xf, size);
+ struct srcdest dest
+ = m32c_decode_srcdest4 (&st, st.insn[1] & 0xf, size);
+ pv_t src_value = m32c_srcdest_fetch (&st, src, size);
+
+ if (m32c_is_arg_spill (&st, dest, src_value))
+ after_last_frame_related_insn = st.next_addr;
+ else if (m32c_is_struct_return (&st, dest, src_value))
+ after_last_frame_related_insn = st.next_addr;
+
+ if (m32c_srcdest_store (&st, dest, src_value, size))
+ break;
+ }
+
+ /* (1) LDC #IMM16, sp */
+ else if (st.insn[0] == 0xeb
+ && st.insn[1] == 0x50)
+ {
+ st.next_addr += 2;
+ st.sp = pv_constant (m32c_udisp16 (&st));
+ }
+
+ else
+ /* We've hit some instruction we don't know how to simulate.
+ Strictly speaking, we should set every value we're
+ tracking to "unknown". But we'll be optimistic, assume
+ that we have enough information already, and stop
+ analysis here. */
+ break;
+ }
+ else
+ {
+ int src_indirect = 0;
+ int dest_indirect = 0;
+ int i = 0;
+
+ gdb_assert (mach == bfd_mach_m32c);
+
+ /* Check for prefix bytes indicating indirect addressing. */
+ if (st.insn[0] == 0x41)
+ {
+ src_indirect = 1;
+ i++;
+ }
+ else if (st.insn[0] == 0x09)
+ {
+ dest_indirect = 1;
+ i++;
+ }
+ else if (st.insn[0] == 0x49)
+ {
+ src_indirect = dest_indirect = 1;
+ i++;
+ }
+
+ /* (1) ENTER #imm8 */
+ if (st.insn[i] == 0xec)
+ {
+ if (m32c_pv_enter (&st, st.insn[i + 1]))
+ break;
+ st.next_addr += 2;
+ }
+
+ /* (1) PUSHM src */
+ else if (st.insn[i] == 0x8f)
+ {
+ int src = st.insn[i + 1];
+ if (m32c_pv_pushm (&st, src))
+ break;
+ st.next_addr += 2;
+
+ if (m32c_pushm_is_reg_save (&st, src))
+ after_last_frame_related_insn = st.next_addr;
+ }
+
+ /* (7) MOV.size:G src, dest */
+ else if ((st.insn[i] & 0x80) == 0x80
+ && (st.insn[i + 1] & 0x0f) == 0x0b
+ && m32c_get_src23 (&st.insn[i]) < 20
+ && m32c_get_dest23 (&st.insn[i]) < 20)
+ {
+ int bw = st.insn[i] & 0x01;
+ int size = bw ? 2 : 1;
+
+ st.next_addr += 2;
+
+ struct srcdest src
+ = m32c_decode_sd23 (&st, m32c_get_src23 (&st.insn[i]),
+ size, src_indirect);
+ struct srcdest dest
+ = m32c_decode_sd23 (&st, m32c_get_dest23 (&st.insn[i]),
+ size, dest_indirect);
+ pv_t src_value = m32c_srcdest_fetch (&st, src, size);
+
+ if (m32c_is_arg_spill (&st, dest, src_value))
+ after_last_frame_related_insn = st.next_addr;
+
+ if (m32c_srcdest_store (&st, dest, src_value, size))
+ break;
+ }
+ /* (2) LDC #IMM24, sp */
+ else if (st.insn[i] == 0xd5
+ && st.insn[i + 1] == 0x29)
+ {
+ st.next_addr += 2;
+ st.sp = pv_constant (m32c_udisp24 (&st));
+ }
+ else
+ /* We've hit some instruction we don't know how to simulate.
+ Strictly speaking, we should set every value we're
+ tracking to "unknown". But we'll be optimistic, assume
+ that we have enough information already, and stop
+ analysis here. */
+ break;
+ }
+
+ /* If this instruction changed the FB or decreased the SP (i.e.,
+ allocated more stack space), then this may be a good place to
+ declare the prologue finished. However, there are some
+ exceptions:
+
+ - If the instruction just changed the FB back to its original
+ value, then that's probably a restore instruction. The
+ prologue should definitely end before that.
+
+ - If the instruction increased the value of the SP (that is,
+ shrunk the frame), then it's probably part of a frame
+ teardown sequence, and the prologue should end before
+ that. */
+
+ if (! pv_is_identical (st.fb, pre_insn_fb))
+ {
+ if (! pv_is_register_k (st.fb, tdep->fb->num, 0))
+ after_last_frame_related_insn = st.next_addr;
+ }
+ else if (! pv_is_identical (st.sp, pre_insn_sp))
+ {
+ /* The comparison of the constants looks odd, there, because
+ .k is unsigned. All it really means is that the SP is
+ lower than it was before the instruction. */
+ if ( pv_is_register (pre_insn_sp, tdep->sp->num)
+ && pv_is_register (st.sp, tdep->sp->num)
+ && ((pre_insn_sp.k - st.sp.k) < (st.sp.k - pre_insn_sp.k)))
+ after_last_frame_related_insn = st.next_addr;
+ }
+
+ st.scan_pc = st.next_addr;
+ }
+
+ /* Did we load a constant value into the stack pointer? */
+ if (pv_is_constant (st.sp))
+ prologue->kind = prologue_first_frame;
+
+ /* Alternatively, did we initialize the frame pointer? Remember
+ that the CFA is the address after the return address. */
+ if (pv_is_register (st.fb, tdep->sp->num))
+ {
+ prologue->kind = prologue_with_frame_ptr;
+ prologue->frame_ptr_offset = st.fb.k;
+ }
+
+ /* Is the frame size a known constant? Remember that frame_size is
+ actually the offset from the CFA to the SP (i.e., a negative
+ value). */
+ else if (pv_is_register (st.sp, tdep->sp->num))
+ {
+ prologue->kind = prologue_sans_frame_ptr;
+ prologue->frame_size = st.sp.k;
+ }
+
+ /* We haven't been able to make sense of this function's frame. Treat
+ it as the first frame. */
+ else
+ prologue->kind = prologue_first_frame;
+
+ /* Record where all the registers were saved. */
+ pv_area_scan (st.stack, check_for_saved, (void *) prologue);
+
+ prologue->prologue_end = after_last_frame_related_insn;
+
+ do_cleanups (back_to);
+}
+
+
+static CORE_ADDR
+m32c_skip_prologue (CORE_ADDR ip)
+{
+ char *name;
+ CORE_ADDR func_addr, func_end, sal_end;
+ struct m32c_prologue p;
+
+ /* Try to find the extent of the function that contains IP. */
+ if (! find_pc_partial_function (ip, &name, &func_addr, &func_end))
+ return ip;
+
+ /* Find end by prologue analysis. */
+ m32c_analyze_prologue (current_gdbarch, ip, func_end, &p);
+ /* Find end by line info. */
+ sal_end = skip_prologue_using_sal (ip);
+ /* Return whichever is lower. */
+ if (sal_end != 0 && sal_end != ip && sal_end < p.prologue_end)
+ return sal_end;
+ else
+ return p.prologue_end;
+}
+
+
+\f
+/* Stack unwinding. */
+
+static struct m32c_prologue *
+m32c_analyze_frame_prologue (struct frame_info *next_frame,
+ void **this_prologue_cache)
+{
+ if (! *this_prologue_cache)
+ {
+ CORE_ADDR func_start = frame_func_unwind (next_frame);
+ CORE_ADDR stop_addr = frame_pc_unwind (next_frame);
+
+ /* If we couldn't find any function containing the PC, then
+ just initialize the prologue cache, but don't do anything. */
+ if (! func_start)
+ stop_addr = func_start;
+
+ *this_prologue_cache = FRAME_OBSTACK_ZALLOC (struct m32c_prologue);
+ m32c_analyze_prologue (get_frame_arch (next_frame),
+ func_start, stop_addr, *this_prologue_cache);
+ }
+
+ return *this_prologue_cache;
+}
+
+
+static CORE_ADDR
+m32c_frame_base (struct frame_info *next_frame,
+ void **this_prologue_cache)
+{
+ struct m32c_prologue *p
+ = m32c_analyze_frame_prologue (next_frame, this_prologue_cache);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (next_frame));
+
+ /* In functions that use alloca, the distance between the stack
+ pointer and the frame base varies dynamically, so we can't use
+ the SP plus static information like prologue analysis to find the
+ frame base. However, such functions must have a frame pointer,
+ to be able to restore the SP on exit. So whenever we do have a
+ frame pointer, use that to find the base. */
+ switch (p->kind)
+ {
+ case prologue_with_frame_ptr:
+ {
+ CORE_ADDR fb
+ = frame_unwind_register_unsigned (next_frame, tdep->fb->num);
+ return fb - p->frame_ptr_offset;
+ }
+
+ case prologue_sans_frame_ptr:
+ {
+ CORE_ADDR sp
+ = frame_unwind_register_unsigned (next_frame, tdep->sp->num);
+ return sp - p->frame_size;
+ }
+
+ case prologue_first_frame:
+ return 0;
+
+ default:
+ gdb_assert (0);
+ }
+}
+
+
+static void
+m32c_this_id (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ struct frame_id *this_id)
+{
+ CORE_ADDR base = m32c_frame_base (next_frame, this_prologue_cache);
+
+ if (base)
+ *this_id = frame_id_build (base, frame_func_unwind (next_frame));
+ /* Otherwise, leave it unset, and that will terminate the backtrace. */
+}
+
+
+static void
+m32c_prev_register (struct frame_info *next_frame,
+ void **this_prologue_cache,
+ int regnum, int *optimizedp,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnump, gdb_byte *bufferp)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (next_frame));
+ struct m32c_prologue *p
+ = m32c_analyze_frame_prologue (next_frame, this_prologue_cache);
+ CORE_ADDR frame_base = m32c_frame_base (next_frame, this_prologue_cache);
+ int reg_size = register_size (get_frame_arch (next_frame), regnum);
+
+ if (regnum == tdep->sp->num)
+ {
+ *optimizedp = 0;
+ *lvalp = not_lval;
+ *addrp = 0;
+ *realnump = -1;
+ if (bufferp)
+ store_unsigned_integer (bufferp, reg_size, frame_base);
+ }
+
+ /* If prologue analysis says we saved this register somewhere,
+ return a description of the stack slot holding it. */
+ else if (p->reg_offset[regnum] != 1)
+ {
+ *optimizedp = 0;
+ *lvalp = lval_memory;
+ *addrp = frame_base + p->reg_offset[regnum];
+ *realnump = -1;
+ if (bufferp)
+ get_frame_memory (next_frame, *addrp, bufferp, reg_size);
+ }
+
+ /* Otherwise, presume we haven't changed the value of this
+ register, and get it from the next frame. */
+ else
+ frame_register_unwind (next_frame, regnum,
+ optimizedp, lvalp, addrp, realnump, bufferp);
+}
+
+
+static const struct frame_unwind m32c_unwind = {
+ NORMAL_FRAME,
+ m32c_this_id,
+ m32c_prev_register
+};
+
+
+static const struct frame_unwind *
+m32c_frame_sniffer (struct frame_info *next_frame)
+{
+ return &m32c_unwind;
+}
+
+
+static CORE_ADDR
+m32c_unwind_pc (struct gdbarch *arch, struct frame_info *next_frame)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ return frame_unwind_register_unsigned (next_frame, tdep->pc->num);
+}
+
+
+static CORE_ADDR
+m32c_unwind_sp (struct gdbarch *arch, struct frame_info *next_frame)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+ return frame_unwind_register_unsigned (next_frame, tdep->sp->num);
+}
+
+\f
+/* Inferior calls. */
+
+/* The calling conventions, according to GCC:
+
+ r8c, m16c
+ ---------
+ First arg may be passed in r1l or r1 if it (1) fits (QImode or
+ HImode), (2) is named, and (3) is an integer or pointer type (no
+ structs, floats, etc). Otherwise, it's passed on the stack.
+
+ Second arg may be passed in r2, same restrictions (but not QImode),
+ even if the first arg is passed on the stack.
+
+ Third and further args are passed on the stack. No padding is
+ used, stack "alignment" is 8 bits.
+
+ m32cm, m32c
+ -----------
+
+ First arg may be passed in r0l or r0, same restrictions as above.
+
+ Second and further args are passed on the stack. Padding is used
+ after QImode parameters (i.e. lower-addressed byte is the value,
+ higher-addressed byte is the padding), stack "alignment" is 16
+ bits. */
+
+
+/* Return true if TYPE is a type that can be passed in registers. (We
+ ignore the size, and pay attention only to the type code;
+ acceptable sizes depends on which register is being considered to
+ hold it.) */
+static int
+m32c_reg_arg_type (struct type *type)
+{
+ enum type_code code = TYPE_CODE (type);
+
+ return (code == TYPE_CODE_INT
+ || code == TYPE_CODE_ENUM
+ || code == TYPE_CODE_PTR
+ || code == TYPE_CODE_REF
+ || code == TYPE_CODE_BOOL
+ || code == TYPE_CODE_CHAR);
+}
+
+
+static CORE_ADDR
+m32c_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
+ struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
+ struct value **args, CORE_ADDR sp, int struct_return,
+ CORE_ADDR struct_addr)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ unsigned long mach = gdbarch_bfd_arch_info (gdbarch)->mach;
+ CORE_ADDR cfa;
+ int i;
+
+ /* The number of arguments given in this function's prototype, or
+ zero if it has a non-prototyped function type. The m32c ABI
+ passes arguments mentioned in the prototype differently from
+ those in the ellipsis of a varargs function, or from those passed
+ to a non-prototyped function. */
+ int num_prototyped_args = 0;
+
+ {
+ struct type *func_type = value_type (function);
+
+ gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC ||
+ TYPE_CODE (func_type) == TYPE_CODE_METHOD);
+
+#if 0
+ /* The ABI description in gcc/config/m32c/m32c.abi says that
+ we need to handle prototyped and non-prototyped functions
+ separately, but the code in GCC doesn't actually do so. */
+ if (TYPE_PROTOTYPED (func_type))
+#endif
+ num_prototyped_args = TYPE_NFIELDS (func_type);
+ }
+
+ /* First, if the function returns an aggregate by value, push a
+ pointer to a buffer for it. This doesn't affect the way
+ subsequent arguments are allocated to registers. */
+ if (struct_return)
+ {
+ int ptr_len = TYPE_LENGTH (tdep->ptr_voyd);
+ sp -= ptr_len;
+ write_memory_unsigned_integer (sp, ptr_len, struct_addr);
+ }
+
+ /* Push the arguments. */
+ for (i = nargs - 1; i >= 0; i--)
+ {
+ struct value *arg = args[i];
+ const gdb_byte *arg_bits = value_contents (arg);
+ struct type *arg_type = value_type (arg);
+ ULONGEST arg_size = TYPE_LENGTH (arg_type);
+
+ /* Can it go in r1 or r1l (for m16c) or r0 or r0l (for m32c)? */
+ if (i == 0
+ && arg_size <= 2
+ && i < num_prototyped_args
+ && m32c_reg_arg_type (arg_type))
+ {
+ /* Extract and re-store as an integer as a terse way to make
+ sure it ends up in the least significant end of r1. (GDB
+ should avoid assuming endianness, even on uni-endian
+ processors.) */
+ ULONGEST u = extract_unsigned_integer (arg_bits, arg_size);
+ struct m32c_reg *reg = (mach == bfd_mach_m16c) ? tdep->r1 : tdep->r0;
+ regcache_cooked_write_unsigned (regcache, reg->num, u);
+ }
+
+ /* Can it go in r2? */
+ else if (mach == bfd_mach_m16c
+ && i == 1
+ && arg_size == 2
+ && i < num_prototyped_args
+ && m32c_reg_arg_type (arg_type))
+ regcache_cooked_write (regcache, tdep->r2->num, arg_bits);
+
+ /* Everything else goes on the stack. */
+ else
+ {
+ sp -= arg_size;
+
+ /* Align the stack. */
+ if (mach == bfd_mach_m32c)
+ sp &= ~1;
+
+ write_memory (sp, arg_bits, arg_size);
+ }
+ }
+
+ /* This is the CFA we use to identify the dummy frame. */
+ cfa = sp;
+
+ /* Push the return address. */
+ sp -= tdep->ret_addr_bytes;
+ write_memory_unsigned_integer (sp, tdep->ret_addr_bytes, bp_addr);
+
+ /* Update the stack pointer. */
+ regcache_cooked_write_unsigned (regcache, tdep->sp->num, sp);
+
+ /* We need to borrow an odd trick from the i386 target here.
+
+ The value we return from this function gets used as the stack
+ address (the CFA) for the dummy frame's ID. The obvious thing is
+ to return the new TOS. However, that points at the return
+ address, saved on the stack, which is inconsistent with the CFA's
+ described by GCC's DWARF 2 .debug_frame information: DWARF 2
+ .debug_frame info uses the address immediately after the saved
+ return address. So you end up with a dummy frame whose CFA
+ points at the return address, but the frame for the function
+ being called has a CFA pointing after the return address: the
+ younger CFA is *greater than* the older CFA. The sanity checks
+ in frame.c don't like that.
+
+ So we try to be consistent with the CFA's used by DWARF 2.
+ Having a dummy frame and a real frame with the *same* CFA is
+ tolerable. */
+ return cfa;
+}
+
+
+static struct frame_id
+m32c_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
+{
+ /* This needs to return a frame ID whose PC is the return address
+ passed to m32c_push_dummy_call, and whose stack_addr is the SP
+ m32c_push_dummy_call returned.
+
+ m32c_unwind_sp gives us the CFA, which is the value the SP had
+ before the return address was pushed. */
+ return frame_id_build (m32c_unwind_sp (gdbarch, next_frame),
+ frame_pc_unwind (next_frame));
+}
+
+
+\f
+/* Return values. */
+
+/* Return value conventions, according to GCC:
+
+ r8c, m16c
+ ---------
+
+ QImode in r0l
+ HImode in r0
+ SImode in r2r0
+ near pointer in r0
+ far pointer in r2r0
+
+ Aggregate values (regardless of size) are returned by pushing a
+ pointer to a temporary area on the stack after the args are pushed.
+ The function fills in this area with the value. Note that this
+ pointer on the stack does not affect how register arguments, if any,
+ are configured.
+
+ m32cm, m32c
+ -----------
+ Same. */
+
+/* Return non-zero if values of type TYPE are returned by storing them
+ in a buffer whose address is passed on the stack, ahead of the
+ other arguments. */
+static int
+m32c_return_by_passed_buf (struct type *type)
+{
+ enum type_code code = TYPE_CODE (type);
+
+ return (code == TYPE_CODE_STRUCT
+ || code == TYPE_CODE_UNION);
+}
+
+static enum return_value_convention
+m32c_return_value (struct gdbarch *gdbarch,
+ struct type *valtype,
+ struct regcache *regcache,
+ gdb_byte *readbuf,
+ const gdb_byte *writebuf)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum return_value_convention conv;
+ ULONGEST valtype_len = TYPE_LENGTH (valtype);
+
+ if (m32c_return_by_passed_buf (valtype))
+ conv = RETURN_VALUE_STRUCT_CONVENTION;
+ else
+ conv = RETURN_VALUE_REGISTER_CONVENTION;
+
+ if (readbuf)
+ {
+ /* We should never be called to find values being returned by
+ RETURN_VALUE_STRUCT_CONVENTION. Those can't be located,
+ unless we made the call ourselves. */
+ gdb_assert (conv == RETURN_VALUE_REGISTER_CONVENTION);
+
+ gdb_assert (valtype_len <= 8);
+
+ /* Anything that fits in r0 is returned there. */
+ if (valtype_len <= TYPE_LENGTH (tdep->r0->type))
+ {
+ ULONGEST u;
+ regcache_cooked_read_unsigned (regcache, tdep->r0->num, &u);
+ store_unsigned_integer (readbuf, valtype_len, u);
+ }
+ else
+ {
+ /* Everything else is passed in mem0, using as many bytes as
+ needed. This is not what the Renesas tools do, but it's
+ what GCC does at the moment. */
+ struct minimal_symbol *mem0
+ = lookup_minimal_symbol ("mem0", NULL, NULL);
+
+ if (! mem0)
+ error ("The return value is stored in memory at 'mem0', "
+ "but GDB cannot find\n"
+ "its address.");
+ read_memory (SYMBOL_VALUE_ADDRESS (mem0), readbuf, valtype_len);
+ }
+ }
+
+ if (writebuf)
+ {
+ /* We should never be called to store values to be returned
+ using RETURN_VALUE_STRUCT_CONVENTION. We have no way of
+ finding the buffer, unless we made the call ourselves. */
+ gdb_assert (conv == RETURN_VALUE_REGISTER_CONVENTION);
+
+ gdb_assert (valtype_len <= 8);
+
+ /* Anything that fits in r0 is returned there. */
+ if (valtype_len <= TYPE_LENGTH (tdep->r0->type))
+ {
+ ULONGEST u = extract_unsigned_integer (writebuf, valtype_len);
+ regcache_cooked_write_unsigned (regcache, tdep->r0->num, u);
+ }
+ else
+ {
+ /* Everything else is passed in mem0, using as many bytes as
+ needed. This is not what the Renesas tools do, but it's
+ what GCC does at the moment. */
+ struct minimal_symbol *mem0
+ = lookup_minimal_symbol ("mem0", NULL, NULL);
+
+ if (! mem0)
+ error ("The return value is stored in memory at 'mem0', "
+ "but GDB cannot find\n"
+ " its address.");
+ write_memory (SYMBOL_VALUE_ADDRESS (mem0),
+ (char *) writebuf, valtype_len);
+ }
+ }
+
+ return conv;
+}
+
+
+\f
+/* Trampolines. */
+
+/* The m16c and m32c use a trampoline function for indirect function
+ calls. An indirect call looks like this:
+
+ ... push arguments ...
+ ... push target function address ...
+ jsr.a m32c_jsri16
+
+ The code for m32c_jsri16 looks like this:
+
+ m32c_jsri16:
+
+ # Save return address.
+ pop.w m32c_jsri_ret
+ pop.b m32c_jsri_ret+2
+
+ # Store target function address.
+ pop.w m32c_jsri_addr
+
+ # Re-push return address.
+ push.b m32c_jsri_ret+2
+ push.w m32c_jsri_ret
+
+ # Call the target function.
+ jmpi.a m32c_jsri_addr
+
+ Without further information, GDB will treat calls to m32c_jsri16
+ like calls to any other function. Since m32c_jsri16 doesn't have
+ debugging information, that normally means that GDB sets a step-
+ resume breakpoint and lets the program continue --- which is not
+ what the user wanted. (Giving the trampoline debugging info
+ doesn't help: the user expects the program to stop in the function
+ their program is calling, not in some trampoline code they've never
+ seen before.)
+
+ The SKIP_TRAMPOLINE_CODE gdbarch method tells GDB how to step
+ through such trampoline functions transparently to the user. When
+ given the address of a trampoline function's first instruction,
+ SKIP_TRAMPOLINE_CODE should return the address of the first
+ instruction of the function really being called. If GDB decides it
+ wants to step into that function, it will set a breakpoint there
+ and silently continue to it.
+
+ We recognize the trampoline by name, and extract the target address
+ directly from the stack. This isn't great, but recognizing by its
+ code sequence seems more fragile. */
+
+static CORE_ADDR
+m32c_skip_trampoline_code (CORE_ADDR stop_pc)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+
+ /* It would be nicer to simply look up the addresses of known
+ trampolines once, and then compare stop_pc with them. However,
+ we'd need to ensure that that cached address got invalidated when
+ someone loaded a new executable, and I'm not quite sure of the
+ best way to do that. find_pc_partial_function does do some
+ caching, so we'll see how this goes. */
+ char *name;
+ CORE_ADDR start, end;
+
+ if (find_pc_partial_function (stop_pc, &name, &start, &end))
+ {
+ /* Are we stopped at the beginning of the trampoline function? */
+ if (strcmp (name, "m32c_jsri16") == 0
+ && stop_pc == start)
+ {
+ /* Get the stack pointer. The return address is at the top,
+ and the target function's address is just below that. We
+ know it's a two-byte address, since the trampoline is
+ m32c_jsri*16*. */
+ CORE_ADDR sp = get_frame_sp (get_current_frame ());
+ CORE_ADDR target
+ = read_memory_unsigned_integer (sp + tdep->ret_addr_bytes, 2);
+
+ /* What we have now is the address of a jump instruction.
+ What we need is the destination of that jump.
+ The opcode is 1 byte, and the destination is the next 3 bytes.
+ */
+ target = read_memory_unsigned_integer (target + 1, 3);
+ return target;
+ }
+ }
+
+ return 0;
+}
+
+
+/* Address/pointer conversions. */
+
+/* On the m16c, there is a 24-bit address space, but only a very few
+ instructions can generate addresses larger than 0xffff: jumps,
+ jumps to subroutines, and the lde/std (load/store extended)
+ instructions.
+
+ Since GCC can only support one size of pointer, we can't have
+ distinct 'near' and 'far' pointer types; we have to pick one size
+ for everything. If we wanted to use 24-bit pointers, then GCC
+ would have to use lde and ste for all memory references, which
+ would be terrible for performance and code size. So the GNU
+ toolchain uses 16-bit pointers for everything, and gives up the
+ ability to have pointers point outside the first 64k of memory.
+
+ However, as a special hack, we let the linker place functions at
+ addresses above 0xffff, as long as it also places a trampoline in
+ the low 64k for every function whose address is taken. Each
+ trampoline consists of a single jmp.a instruction that jumps to the
+ function's real entry point. Pointers to functions can be 16 bits
+ long, even though the functions themselves are at higher addresses:
+ the pointers refer to the trampolines, not the functions.
+
+ This complicates things for GDB, however: given the address of a
+ function (from debug info or linker symbols, say) which could be
+ anywhere in the 24-bit address space, how can we find an
+ appropriate 16-bit value to use as a pointer to it?
+
+ If the linker has not generated a trampoline for the function,
+ we're out of luck. Well, I guess we could malloc some space and
+ write a jmp.a instruction to it, but I'm not going to get into that
+ at the moment.
+
+ If the linker has generated a trampoline for the function, then it
+ also emitted a symbol for the trampoline: if the function's linker
+ symbol is named NAME, then the function's trampoline's linker
+ symbol is named NAME.plt.
+
+ So, given a code address:
+ - We try to find a linker symbol at that address.
+ - If we find such a symbol named NAME, we look for a linker symbol
+ named NAME.plt.
+ - If we find such a symbol, we assume it is a trampoline, and use
+ its address as the pointer value.
+
+ And, given a function pointer:
+ - We try to find a linker symbol at that address named NAME.plt.
+ - If we find such a symbol, we look for a linker symbol named NAME.
+ - If we find that, we provide that as the function's address.
+ - If any of the above steps fail, we return the original address
+ unchanged; it might really be a function in the low 64k.
+
+ See? You *knew* there was a reason you wanted to be a computer
+ programmer! :) */
+
+static void
+m32c_m16c_address_to_pointer (struct type *type, gdb_byte *buf, CORE_ADDR addr)
+{
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_PTR ||
+ TYPE_CODE (type) == TYPE_CODE_REF);
+
+ enum type_code target_code = TYPE_CODE (TYPE_TARGET_TYPE (type));
+
+ if (target_code == TYPE_CODE_FUNC || target_code == TYPE_CODE_METHOD)
+ {
+ /* Try to find a linker symbol at this address. */
+ struct minimal_symbol *func_msym = lookup_minimal_symbol_by_pc (addr);
+
+ if (! func_msym)
+ error ("Cannot convert code address %s to function pointer:\n"
+ "couldn't find a symbol at that address, to find trampoline.",
+ paddr_nz (addr));
+
+ char *func_name = SYMBOL_LINKAGE_NAME (func_msym);
+ char *tramp_name = xmalloc (strlen (func_name) + 5);
+ strcpy (tramp_name, func_name);
+ strcat (tramp_name, ".plt");
+
+ /* Try to find a linker symbol for the trampoline. */
+ struct minimal_symbol *tramp_msym
+ = lookup_minimal_symbol (tramp_name, NULL, NULL);
+
+ /* We've either got another copy of the name now, or don't need
+ the name any more. */
+ xfree (tramp_name);
+
+ if (! tramp_msym)
+ error ("Cannot convert code address %s to function pointer:\n"
+ "couldn't find trampoline named '%s.plt'.",
+ paddr_nz (addr), func_name);
+
+ /* The trampoline's address is our pointer. */
+ addr = SYMBOL_VALUE_ADDRESS (tramp_msym);
+ }
+
+ store_unsigned_integer (buf, TYPE_LENGTH (type), addr);
+}
+
+
+static CORE_ADDR
+m32c_m16c_pointer_to_address (struct type *type, const gdb_byte *buf)
+{
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_PTR ||
+ TYPE_CODE (type) == TYPE_CODE_REF);
+
+ CORE_ADDR ptr = extract_unsigned_integer (buf, TYPE_LENGTH (type));
+
+ enum type_code target_code = TYPE_CODE (TYPE_TARGET_TYPE (type));
+
+ if (target_code == TYPE_CODE_FUNC || target_code == TYPE_CODE_METHOD)
+ {
+ /* See if there is a minimal symbol at that address whose name is
+ "NAME.plt". */
+ struct minimal_symbol *ptr_msym = lookup_minimal_symbol_by_pc (ptr);
+
+ if (ptr_msym)
+ {
+ char *ptr_msym_name = SYMBOL_LINKAGE_NAME (ptr_msym);
+ int len = strlen (ptr_msym_name);
+
+ if (len > 4
+ && strcmp (ptr_msym_name + len - 4, ".plt") == 0)
+ {
+ /* We have a .plt symbol; try to find the symbol for the
+ corresponding function.
+
+ Since the trampoline contains a jump instruction, we
+ could also just extract the jump's target address. I
+ don't see much advantage one way or the other. */
+ char *func_name = xmalloc (len - 4 + 1);
+ memcpy (func_name, ptr_msym_name, len - 4);
+ func_name[len - 4] = '\0';
+ struct minimal_symbol *func_msym
+ = lookup_minimal_symbol (func_name, NULL, NULL);
+
+ /* If we do have such a symbol, return its value as the
+ function's true address. */
+ if (func_msym)
+ ptr = SYMBOL_VALUE_ADDRESS (func_msym);
+ }
+ }
+ }
+
+ return ptr;
+}
+
+
+\f
+/* Initialization. */
+
+static struct gdbarch *
+m32c_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+{
+ struct gdbarch *arch;
+ struct gdbarch_tdep *tdep;
+ unsigned long mach = info.bfd_arch_info->mach;
+
+ /* Find a candidate among the list of architectures we've created
+ already. */
+ for (arches = gdbarch_list_lookup_by_info (arches, &info);
+ arches != NULL;
+ arches = gdbarch_list_lookup_by_info (arches->next, &info))
+ return arches->gdbarch;
+
+ tdep = xcalloc (1, sizeof (*tdep));
+ arch = gdbarch_alloc (&info, tdep);
+
+ /* Essential types. */
+ make_types (arch);
+
+ /* Address/pointer conversions. */
+ if (mach == bfd_mach_m16c)
+ {
+ set_gdbarch_address_to_pointer (arch, m32c_m16c_address_to_pointer);
+ set_gdbarch_pointer_to_address (arch, m32c_m16c_pointer_to_address);
+ }
+
+ /* Register set. */
+ make_regs (arch);
+
+ /* Disassembly. */
+ set_gdbarch_print_insn (arch, print_insn_m32c);
+
+ /* Breakpoints. */
+ set_gdbarch_breakpoint_from_pc (arch, m32c_breakpoint_from_pc);
+
+ /* Prologue analysis and unwinding. */
+ set_gdbarch_inner_than (arch, core_addr_lessthan);
+ set_gdbarch_skip_prologue (arch, m32c_skip_prologue);
+ set_gdbarch_unwind_pc (arch, m32c_unwind_pc);
+ set_gdbarch_unwind_sp (arch, m32c_unwind_sp);
+#if 0
+ /* I'm dropping the dwarf2 sniffer because it has a few problems.
+ They may be in the dwarf2 cfi code in GDB, or they may be in
+ the debug info emitted by the upstream toolchain. I don't
+ know which, but I do know that the prologue analyzer works better.
+ MVS 04/13/06
+ */
+ frame_unwind_append_sniffer (arch, dwarf2_frame_sniffer);
+#endif
+ frame_unwind_append_sniffer (arch, m32c_frame_sniffer);
+
+ /* Inferior calls. */
+ set_gdbarch_push_dummy_call (arch, m32c_push_dummy_call);
+ set_gdbarch_return_value (arch, m32c_return_value);
+ set_gdbarch_unwind_dummy_id (arch, m32c_unwind_dummy_id);
+
+ /* Trampolines. */
+ set_gdbarch_skip_trampoline_code (arch, m32c_skip_trampoline_code);
+
+ return arch;
+}
+
+
+void
+_initialize_m32c_tdep (void)
+{
+ register_gdbarch_init (bfd_arch_m32c, m32c_gdbarch_init);
+
+ m32c_dma_reggroup = reggroup_new ("dma", USER_REGGROUP);
+}
projects / deliverable / binutils-gdb.git / commitdiff
