return mips_regnum (gdbarch)->fp0 + 12;
}
+/* Return 1 if REGNUM refers to a floating-point general register, raw
+ or cooked. Otherwise return 0. */
+
+static int
+mips_float_register_p (struct gdbarch *gdbarch, int regnum)
+{
+ int rawnum = regnum % gdbarch_num_regs (gdbarch);
+
+ return (rawnum >= mips_regnum (gdbarch)->fp0
+ && rawnum < mips_regnum (gdbarch)->fp0 + 32);
+}
+
#define MIPS_EABI(gdbarch) (gdbarch_tdep (gdbarch)->mips_abi \
== MIPS_ABI_EABI32 \
|| gdbarch_tdep (gdbarch)->mips_abi == MIPS_ABI_EABI64)
#define MIPS_FPU_TYPE(gdbarch) (gdbarch_tdep (gdbarch)->mips_fpu_type)
-/* MIPS16 function addresses are odd (bit 0 is set). Here are some
- functions to test, set, or clear bit 0 of addresses. */
-
-static CORE_ADDR
-is_mips16_addr (CORE_ADDR addr)
-{
- return ((addr) & 1);
-}
-
-static CORE_ADDR
-unmake_mips16_addr (CORE_ADDR addr)
-{
- return ((addr) & ~(CORE_ADDR) 1);
-}
-
-static CORE_ADDR
-make_mips16_addr (CORE_ADDR addr)
-{
- return ((addr) | (CORE_ADDR) 1);
-}
-
/* Return the MIPS ABI associated with GDBARCH. */
enum mips_abi
mips_abi (struct gdbarch *gdbarch)
}
}
+/* MIPS16 function addresses are odd (bit 0 is set). Here are some
+ functions to test, set, or clear bit 0 of addresses. */
+
+static CORE_ADDR
+is_mips16_addr (CORE_ADDR addr)
+{
+ return ((addr) & 1);
+}
+
+static CORE_ADDR
+unmake_mips16_addr (CORE_ADDR addr)
+{
+ return ((addr) & ~(CORE_ADDR) 1);
+}
+
+static CORE_ADDR
+make_mips16_addr (CORE_ADDR addr)
+{
+ return ((addr) | (CORE_ADDR) 1);
+}
+
/* Functions for setting and testing a bit in a minimal symbol that
marks it as 16-bit function. The MSB of the minimal symbol's
"info" field is used for this purpose.
static void
mips_elf_make_msymbol_special (asymbol * sym, struct minimal_symbol *msym)
{
- if (((elf_symbol_type *) (sym))->internal_elf_sym.st_other == STO_MIPS16)
+ if (ELF_ST_IS_MIPS16 (((elf_symbol_type *)
+ (sym))->internal_elf_sym.st_other))
{
MSYMBOL_TARGET_FLAG_1 (msym) = 1;
}
{
return (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG
&& register_size (gdbarch, regnum) == 4
- && (regnum % gdbarch_num_regs (gdbarch))
- >= mips_regnum (gdbarch)->fp0
- && (regnum % gdbarch_num_regs (gdbarch))
- < mips_regnum (gdbarch)->fp0 + 32
+ && mips_float_register_p (gdbarch, regnum)
&& TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) == 8);
}
mips_register_type (struct gdbarch *gdbarch, int regnum)
{
gdb_assert (regnum >= 0 && regnum < 2 * gdbarch_num_regs (gdbarch));
- if ((regnum % gdbarch_num_regs (gdbarch)) >= mips_regnum (gdbarch)->fp0
- && (regnum % gdbarch_num_regs (gdbarch))
- < mips_regnum (gdbarch)->fp0 + 32)
+ if (mips_float_register_p (gdbarch, regnum))
{
/* The floating-point registers raw, or cooked, always match
mips_isa_regsize(), and also map 1:1, byte for byte. */
return is_mips16_addr (memaddr);
}
+/* Various MIPS16 thunk (aka stub or trampoline) names. */
+
+static const char mips_str_mips16_call_stub[] = "__mips16_call_stub_";
+static const char mips_str_mips16_ret_stub[] = "__mips16_ret_";
+static const char mips_str_call_fp_stub[] = "__call_stub_fp_";
+static const char mips_str_call_stub[] = "__call_stub_";
+static const char mips_str_fn_stub[] = "__fn_stub_";
+
+/* This is used as a PIC thunk prefix. */
+
+static const char mips_str_pic[] = ".pic.";
+
+/* Return non-zero if the PC is inside a call thunk (aka stub or
+ trampoline) that should be treated as a temporary frame. */
+
+static int
+mips_in_frame_stub (CORE_ADDR pc)
+{
+ CORE_ADDR start_addr;
+ const char *name;
+
+ /* Find the starting address of the function containing the PC. */
+ if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
+ return 0;
+
+ /* If the PC is in __mips16_call_stub_*, this is a call/return stub. */
+ if (strncmp (name, mips_str_mips16_call_stub,
+ strlen (mips_str_mips16_call_stub)) == 0)
+ return 1;
+ /* If the PC is in __call_stub_*, this is a call/return or a call stub. */
+ if (strncmp (name, mips_str_call_stub, strlen (mips_str_call_stub)) == 0)
+ return 1;
+ /* If the PC is in __fn_stub_*, this is a call stub. */
+ if (strncmp (name, mips_str_fn_stub, strlen (mips_str_fn_stub)) == 0)
+ return 1;
+
+ return 0; /* Not a stub. */
+}
+
/* MIPS believes that the PC has a sign extended value. Perhaps the
all registers should be sign extended for simplicity? */
static CORE_ADDR
mips_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
- ULONGEST pc;
+ CORE_ADDR pc;
pc = frame_unwind_register_signed
(next_frame, gdbarch_num_regs (gdbarch) + mips_regnum (gdbarch)->pc);
if (is_mips16_addr (pc))
pc = unmake_mips16_addr (pc);
+ /* macro/2012-04-20: This hack skips over MIPS16 call thunks as
+ intermediate frames. In this case we can get the caller's address
+ from $ra, or if $ra contains an address within a thunk as well, then
+ it must be in the return path of __mips16_call_stub_{s,d}{f,c}_{0..10}
+ and thus the caller's address is in $s2. */
+ if (frame_relative_level (next_frame) >= 0 && mips_in_frame_stub (pc))
+ {
+ pc = frame_unwind_register_signed
+ (next_frame, gdbarch_num_regs (gdbarch) + MIPS_RA_REGNUM);
+ if (is_mips16_addr (pc))
+ pc = unmake_mips16_addr (pc);
+ if (mips_in_frame_stub (pc))
+ {
+ pc = frame_unwind_register_signed
+ (next_frame, gdbarch_num_regs (gdbarch) + MIPS_S2_REGNUM);
+ if (is_mips16_addr (pc))
+ pc = unmake_mips16_addr (pc);
+ }
+ }
return pc;
}
static int
mips_about_to_return (struct gdbarch *gdbarch, CORE_ADDR pc)
{
- if (mips_pc_is_mips16 (pc))
- /* This mips16 case isn't necessarily reliable. Sometimes the compiler
- generates a "jr $ra"; other times it generates code to load
- the return address from the stack to an accessible register (such
- as $a3), then a "jr" using that register. This second case
- is almost impossible to distinguish from an indirect jump
- used for switch statements, so we don't even try. */
- return mips_fetch_instruction (gdbarch, pc) == 0xe820; /* jr $ra */
- else
- return mips_fetch_instruction (gdbarch, pc) == 0x3e00008; /* jr $ra */
+ ULONGEST insn;
+ ULONGEST hint;
+
+ /* This used to check for MIPS16, but this piece of code is never
+ called for MIPS16 functions. */
+ gdb_assert (!mips_pc_is_mips16 (pc));
+
+ insn = mips_fetch_instruction (gdbarch, pc);
+ hint = 0x7c0;
+ return (insn & ~hint) == 0x3e00008; /* jr(.hb) $ra */
}
if (mips_debug)
fprintf_unfiltered (gdb_stderr, "Return float in $f0 and $f2\n");
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0),
8, gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0 + 2,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0 + 2),
8, gdbarch_byte_order (gdbarch),
readbuf ? readbuf + 8 : readbuf,
writebuf ? writebuf + 8 : writebuf, 0);
if (mips_debug)
fprintf_unfiltered (gdb_stderr, "Return float in $fp0\n");
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0),
TYPE_LENGTH (type),
gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
if (mips_debug)
fprintf_unfiltered (gdb_stderr, "Return float in $fp0\n");
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0),
TYPE_LENGTH (type),
gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
{
case BFD_ENDIAN_LITTLE:
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0 +
- 0, 4, gdbarch_byte_order (gdbarch),
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0 + 0),
+ 4, gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0 + 1,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0 + 1),
4, gdbarch_byte_order (gdbarch),
readbuf, writebuf, 4);
break;
case BFD_ENDIAN_BIG:
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0 + 1,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0 + 1),
4, gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0 + 0,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0 + 0),
4, gdbarch_byte_order (gdbarch),
readbuf, writebuf, 4);
break;
if (mips_debug)
fprintf_unfiltered (gdb_stderr, "Return float in $fp0\n");
mips_xfer_register (gdbarch, regcache,
- gdbarch_num_regs (gdbarch)
- + mips_regnum (gdbarch)->fp0,
+ (gdbarch_num_regs (gdbarch)
+ + mips_regnum (gdbarch)->fp0),
TYPE_LENGTH (type),
gdbarch_byte_order (gdbarch),
readbuf, writebuf, 0);
struct value_print_options opts;
struct value *val;
- if (TYPE_CODE (register_type (gdbarch, regnum)) == TYPE_CODE_FLT)
+ if (mips_float_register_p (gdbarch, regnum))
{
mips_print_fp_register (file, frame, regnum);
return;
{
if (*gdbarch_register_name (gdbarch, regnum) == '\0')
continue; /* unused register */
- if (TYPE_CODE (register_type (gdbarch, regnum)) ==
- TYPE_CODE_FLT)
+ if (mips_float_register_p (gdbarch, regnum))
break; /* End the row: reached FP register. */
/* Large registers are handled separately. */
if (register_size (gdbarch, regnum) > mips_abi_regsize (gdbarch))
{
if (*gdbarch_register_name (gdbarch, regnum) == '\0')
continue; /* unused register */
- if (TYPE_CODE (register_type (gdbarch, regnum)) ==
- TYPE_CODE_FLT)
+ if (mips_float_register_p (gdbarch, regnum))
break; /* End row: reached FP register. */
if (register_size (gdbarch, regnum) > mips_abi_regsize (gdbarch))
break; /* End row: large register. */
while (regnum < gdbarch_num_regs (gdbarch)
+ gdbarch_num_pseudo_regs (gdbarch))
{
- if (TYPE_CODE (register_type (gdbarch, regnum)) ==
- TYPE_CODE_FLT)
+ if (mips_float_register_p (gdbarch, regnum))
{
if (all) /* True for "INFO ALL-REGISTERS" command. */
regnum = print_fp_register_row (file, frame, regnum);
return bpaddr;
}
-/* If PC is in a mips16 call or return stub, return the address of the target
- PC, which is either the callee or the caller. There are several
+/* Return non-zero if SUFFIX is one of the numeric suffixes used for MIPS16
+ call stubs, one of 1, 2, 5, 6, 9, 10, or, if ZERO is non-zero, also 0. */
+
+static int
+mips_is_stub_suffix (const char *suffix, int zero)
+{
+ switch (suffix[0])
+ {
+ case '0':
+ return zero && suffix[1] == '\0';
+ case '1':
+ return suffix[1] == '\0' || (suffix[1] == '0' && suffix[2] == '\0');
+ case '2':
+ case '5':
+ case '6':
+ case '9':
+ return suffix[1] == '\0';
+ default:
+ return 0;
+ }
+}
+
+/* Return non-zero if MODE is one of the mode infixes used for MIPS16
+ call stubs, one of sf, df, sc, or dc. */
+
+static int
+mips_is_stub_mode (const char *mode)
+{
+ return ((mode[0] == 's' || mode[0] == 'd')
+ && (mode[1] == 'f' || mode[1] == 'c'));
+}
+
+/* Code at PC is a compiler-generated stub. Such a stub for a function
+ bar might have a name like __fn_stub_bar, and might look like this:
+
+ mfc1 $4, $f13
+ mfc1 $5, $f12
+ mfc1 $6, $f15
+ mfc1 $7, $f14
+
+ followed by (or interspersed with):
+
+ j bar
+
+ or:
+
+ lui $25, %hi(bar)
+ addiu $25, $25, %lo(bar)
+ jr $25
+
+ ($1 may be used in old code; for robustness we accept any register)
+ or, in PIC code:
+
+ lui $28, %hi(_gp_disp)
+ addiu $28, $28, %lo(_gp_disp)
+ addu $28, $28, $25
+ lw $25, %got(bar)
+ addiu $25, $25, %lo(bar)
+ jr $25
+
+ In the case of a __call_stub_bar stub, the sequence to set up
+ arguments might look like this:
+
+ mtc1 $4, $f13
+ mtc1 $5, $f12
+ mtc1 $6, $f15
+ mtc1 $7, $f14
+
+ followed by (or interspersed with) one of the jump sequences above.
+
+ In the case of a __call_stub_fp_bar stub, JAL or JALR is used instead
+ of J or JR, respectively, followed by:
+
+ mfc1 $2, $f0
+ mfc1 $3, $f1
+ jr $18
+
+ We are at the beginning of the stub here, and scan down and extract
+ the target address from the jump immediate instruction or, if a jump
+ register instruction is used, from the register referred. Return
+ the value of PC calculated or 0 if inconclusive.
+
+ The limit on the search is arbitrarily set to 20 instructions. FIXME. */
+
+static CORE_ADDR
+mips_get_mips16_fn_stub_pc (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ int addrreg = MIPS_ZERO_REGNUM;
+ CORE_ADDR start_pc = pc;
+ CORE_ADDR target_pc = 0;
+ CORE_ADDR addr = 0;
+ CORE_ADDR gp = 0;
+ int status = 0;
+ int i;
+
+ for (i = 0;
+ status == 0 && target_pc == 0 && i < 20;
+ i++, pc += MIPS_INSN32_SIZE)
+ {
+ ULONGEST inst = mips_fetch_instruction (gdbarch, pc);
+ CORE_ADDR imm;
+ int rt;
+ int rs;
+ int rd;
+
+ switch (itype_op (inst))
+ {
+ case 0: /* SPECIAL */
+ switch (rtype_funct (inst))
+ {
+ case 8: /* JR */
+ case 9: /* JALR */
+ rs = rtype_rs (inst);
+ if (rs == MIPS_GP_REGNUM)
+ target_pc = gp; /* Hmm... */
+ else if (rs == addrreg)
+ target_pc = addr;
+ break;
+
+ case 0x21: /* ADDU */
+ rt = rtype_rt (inst);
+ rs = rtype_rs (inst);
+ rd = rtype_rd (inst);
+ if (rd == MIPS_GP_REGNUM
+ && ((rs == MIPS_GP_REGNUM && rt == MIPS_T9_REGNUM)
+ || (rs == MIPS_T9_REGNUM && rt == MIPS_GP_REGNUM)))
+ gp += start_pc;
+ break;
+ }
+ break;
+
+ case 2: /* J */
+ case 3: /* JAL */
+ target_pc = jtype_target (inst) << 2;
+ target_pc += ((pc + 4) & ~(CORE_ADDR) 0x0fffffff);
+ break;
+
+ case 9: /* ADDIU */
+ rt = itype_rt (inst);
+ rs = itype_rs (inst);
+ if (rt == rs)
+ {
+ imm = (itype_immediate (inst) ^ 0x8000) - 0x8000;
+ if (rt == MIPS_GP_REGNUM)
+ gp += imm;
+ else if (rt == addrreg)
+ addr += imm;
+ }
+ break;
+
+ case 0xf: /* LUI */
+ rt = itype_rt (inst);
+ imm = ((itype_immediate (inst) ^ 0x8000) - 0x8000) << 16;
+ if (rt == MIPS_GP_REGNUM)
+ gp = imm;
+ else if (rt != MIPS_ZERO_REGNUM)
+ {
+ addrreg = rt;
+ addr = imm;
+ }
+ break;
+
+ case 0x23: /* LW */
+ rt = itype_rt (inst);
+ rs = itype_rs (inst);
+ imm = (itype_immediate (inst) ^ 0x8000) - 0x8000;
+ if (gp != 0 && rs == MIPS_GP_REGNUM)
+ {
+ gdb_byte buf[4];
+
+ memset (buf, 0, sizeof (buf));
+ status = target_read_memory (gp + imm, buf, sizeof (buf));
+ addrreg = rt;
+ addr = extract_signed_integer (buf, sizeof (buf), byte_order);
+ }
+ break;
+ }
+ }
+
+ return target_pc;
+}
+
+/* If PC is in a MIPS16 call or return stub, return the address of the
+ target PC, which is either the callee or the caller. There are several
cases which must be handled:
- * If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
- target PC is in $31 ($ra).
+ * If the PC is in __mips16_ret_{d,s}{f,c}, this is a return stub
+ and the target PC is in $31 ($ra).
* If the PC is in __mips16_call_stub_{1..10}, this is a call stub
- and the target PC is in $2.
- * If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
- before the jal instruction, this is effectively a call stub
- and the target PC is in $2. Otherwise this is effectively
- a return stub and the target PC is in $18.
-
- See the source code for the stubs in gcc/config/mips/mips16.S for
+ and the target PC is in $2.
+ * If the PC at the start of __mips16_call_stub_{s,d}{f,c}_{0..10},
+ i.e. before the JALR instruction, this is effectively a call stub
+ and the target PC is in $2. Otherwise this is effectively
+ a return stub and the target PC is in $18.
+ * If the PC is at the start of __call_stub_fp_*, i.e. before the
+ JAL or JALR instruction, this is effectively a call stub and the
+ target PC is buried in the instruction stream. Otherwise this
+ is effectively a return stub and the target PC is in $18.
+ * If the PC is in __call_stub_* or in __fn_stub_*, this is a call
+ stub and the target PC is buried in the instruction stream.
+
+ See the source code for the stubs in gcc/config/mips/mips16.S, or the
+ stub builder in gcc/config/mips/mips.c (mips16_build_call_stub) for the
gory details. */
static CORE_ADDR
mips_skip_mips16_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
- const char *name;
CORE_ADDR start_addr;
+ const char *name;
+ size_t prefixlen;
/* Find the starting address and name of the function containing the PC. */
if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
return 0;
- /* If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
- target PC is in $31 ($ra). */
- if (strcmp (name, "__mips16_ret_sf") == 0
- || strcmp (name, "__mips16_ret_df") == 0)
- return get_frame_register_signed (frame, MIPS_RA_REGNUM);
-
- if (strncmp (name, "__mips16_call_stub_", 19) == 0)
+ /* If the PC is in __mips16_ret_{d,s}{f,c}, this is a return stub
+ and the target PC is in $31 ($ra). */
+ prefixlen = strlen (mips_str_mips16_ret_stub);
+ if (strncmp (name, mips_str_mips16_ret_stub, prefixlen) == 0
+ && mips_is_stub_mode (name + prefixlen)
+ && name[prefixlen + 2] == '\0')
+ return get_frame_register_signed
+ (frame, gdbarch_num_regs (gdbarch) + MIPS_RA_REGNUM);
+
+ /* If the PC is in __mips16_call_stub_*, this is one of the call
+ call/return stubs. */
+ prefixlen = strlen (mips_str_mips16_call_stub);
+ if (strncmp (name, mips_str_mips16_call_stub, prefixlen) == 0)
{
/* If the PC is in __mips16_call_stub_{1..10}, this is a call stub
and the target PC is in $2. */
- if (name[19] >= '0' && name[19] <= '9')
- return get_frame_register_signed (frame, 2);
+ if (mips_is_stub_suffix (name + prefixlen, 0))
+ return get_frame_register_signed
+ (frame, gdbarch_num_regs (gdbarch) + MIPS_V0_REGNUM);
- /* If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
- before the jal instruction, this is effectively a call stub
+ /* If the PC at the start of __mips16_call_stub_{s,d}{f,c}_{0..10},
+ i.e. before the JALR instruction, this is effectively a call stub
and the target PC is in $2. Otherwise this is effectively
a return stub and the target PC is in $18. */
- else if (name[19] == 's' || name[19] == 'd')
+ else if (mips_is_stub_mode (name + prefixlen)
+ && name[prefixlen + 2] == '_'
+ && mips_is_stub_suffix (name + prefixlen + 3, 0))
{
if (pc == start_addr)
- {
- /* Check if the target of the stub is a compiler-generated
- stub. Such a stub for a function bar might have a name
- like __fn_stub_bar, and might look like this:
- mfc1 $4,$f13
- mfc1 $5,$f12
- mfc1 $6,$f15
- mfc1 $7,$f14
- la $1,bar (becomes a lui/addiu pair)
- jr $1
- So scan down to the lui/addi and extract the target
- address from those two instructions. */
-
- CORE_ADDR target_pc = get_frame_register_signed (frame, 2);
- int i;
-
- /* See if the name of the target function is __fn_stub_*. */
- if (find_pc_partial_function (target_pc, &name, NULL, NULL) ==
- 0)
- return target_pc;
- if (strncmp (name, "__fn_stub_", 10) != 0
- && strcmp (name, "etext") != 0
- && strcmp (name, "_etext") != 0)
- return target_pc;
-
- /* Scan through this _fn_stub_ code for the lui/addiu pair.
- The limit on the search is arbitrarily set to 20
- instructions. FIXME. */
- for (i = 0, pc = 0; i < 20; i++, target_pc += MIPS_INSN32_SIZE)
- {
- ULONGEST inst = mips_fetch_instruction (gdbarch, target_pc);
- CORE_ADDR addr = inst;
-
- if ((inst & 0xffff0000) == 0x3c010000) /* lui $at */
- pc = (((addr & 0xffff) ^ 0x8000) - 0x8000) << 16;
- /* high word */
- else if ((inst & 0xffff0000) == 0x24210000) /* addiu $at */
- return pc + ((addr & 0xffff) ^ 0x8000) - 0x8000;
- /* low word */
- }
-
- /* Couldn't find the lui/addui pair, so return stub address. */
- return target_pc;
- }
+ /* This is the 'call' part of a call stub. The return
+ address is in $2. */
+ return get_frame_register_signed
+ (frame, gdbarch_num_regs (gdbarch) + MIPS_V0_REGNUM);
else
/* This is the 'return' part of a call stub. The return
- address is in $r18. */
- return get_frame_register_signed (frame, 18);
+ address is in $18. */
+ return get_frame_register_signed
+ (frame, gdbarch_num_regs (gdbarch) + MIPS_S2_REGNUM);
}
+ else
+ return 0; /* Not a stub. */
+ }
+
+ /* If the PC is in __call_stub_* or __fn_stub*, this is one of the
+ compiler-generated call or call/return stubs. */
+ if (strncmp (name, mips_str_fn_stub, strlen (mips_str_fn_stub)) == 0
+ || strncmp (name, mips_str_call_stub, strlen (mips_str_call_stub)) == 0)
+ {
+ if (pc == start_addr)
+ /* This is the 'call' part of a call stub. Call this helper
+ to scan through this code for interesting instructions
+ and determine the final PC. */
+ return mips_get_mips16_fn_stub_pc (frame, pc);
+ else
+ /* This is the 'return' part of a call stub. The return address
+ is in $18. */
+ return get_frame_register_signed
+ (frame, gdbarch_num_regs (gdbarch) + MIPS_S2_REGNUM);
}
- return 0; /* not a stub */
+
+ return 0; /* Not a stub. */
+}
+
+/* Return non-zero if the PC is inside a return thunk (aka stub or trampoline).
+ This implements the IN_SOLIB_RETURN_TRAMPOLINE macro. */
+
+static int
+mips_in_return_stub (struct gdbarch *gdbarch, CORE_ADDR pc, const char *name)
+{
+ CORE_ADDR start_addr;
+ size_t prefixlen;
+
+ /* Find the starting address of the function containing the PC. */
+ if (find_pc_partial_function (pc, NULL, &start_addr, NULL) == 0)
+ return 0;
+
+ /* If the PC is in __mips16_call_stub_{s,d}{f,c}_{0..10} but not at
+ the start, i.e. after the JALR instruction, this is effectively
+ a return stub. */
+ prefixlen = strlen (mips_str_mips16_call_stub);
+ if (pc != start_addr
+ && strncmp (name, mips_str_mips16_call_stub, prefixlen) == 0
+ && mips_is_stub_mode (name + prefixlen)
+ && name[prefixlen + 2] == '_'
+ && mips_is_stub_suffix (name + prefixlen + 3, 1))
+ return 1;
+
+ /* If the PC is in __call_stub_fp_* but not at the start, i.e. after
+ the JAL or JALR instruction, this is effectively a return stub. */
+ prefixlen = strlen (mips_str_call_fp_stub);
+ if (pc != start_addr
+ && strncmp (name, mips_str_call_fp_stub, prefixlen) == 0)
+ return 1;
+
+ /* Consume the .pic. prefix of any PIC stub, this function must return
+ true when the PC is in a PIC stub of a __mips16_ret_{d,s}{f,c} stub
+ or the call stub path will trigger in handle_inferior_event causing
+ it to go astray. */
+ prefixlen = strlen (mips_str_pic);
+ if (strncmp (name, mips_str_pic, prefixlen) == 0)
+ name += prefixlen;
+
+ /* If the PC is in __mips16_ret_{d,s}{f,c}, this is a return stub. */
+ prefixlen = strlen (mips_str_mips16_ret_stub);
+ if (strncmp (name, mips_str_mips16_ret_stub, prefixlen) == 0
+ && mips_is_stub_mode (name + prefixlen)
+ && name[prefixlen + 2] == '\0')
+ return 1;
+
+ return 0; /* Not a stub. */
}
/* If the current PC is the start of a non-PIC-to-PIC stub, return the
&& (stub_words[1] & 0xfc000000U) == 0x08000000
&& (stub_words[2] & 0xffff0000U) == 0x27390000
&& stub_words[3] == 0x00000000)
- return (((stub_words[0] & 0x0000ffff) << 16)
- + (stub_words[2] & 0x0000ffff));
+ return ((((stub_words[0] & 0x0000ffff) << 16)
+ + (stub_words[2] & 0x0000ffff)) ^ 0x8000) - 0x8000;
}
/* Not a recognized stub. */
static CORE_ADDR
mips_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
+ CORE_ADDR requested_pc = pc;
CORE_ADDR target_pc;
+ CORE_ADDR new_pc;
- target_pc = mips_skip_mips16_trampoline_code (frame, pc);
- if (target_pc)
- return target_pc;
+ do
+ {
+ target_pc = pc;
- target_pc = find_solib_trampoline_target (frame, pc);
- if (target_pc)
- return target_pc;
+ new_pc = mips_skip_mips16_trampoline_code (frame, pc);
+ if (new_pc)
+ {
+ pc = new_pc;
+ if (is_mips16_addr (pc))
+ pc = unmake_mips16_addr (pc);
+ }
- target_pc = mips_skip_pic_trampoline_code (frame, pc);
- if (target_pc)
- return target_pc;
+ new_pc = find_solib_trampoline_target (frame, pc);
+ if (new_pc)
+ {
+ pc = new_pc;
+ if (is_mips16_addr (pc))
+ pc = unmake_mips16_addr (pc);
+ }
- return 0;
+ new_pc = mips_skip_pic_trampoline_code (frame, pc);
+ if (new_pc)
+ {
+ pc = new_pc;
+ if (is_mips16_addr (pc))
+ pc = unmake_mips16_addr (pc);
+ }
+ }
+ while (pc != target_pc);
+
+ return pc != requested_pc ? pc : 0;
}
/* Convert a dbx stab register number (from `r' declaration) to a GDB
set_gdbarch_skip_trampoline_code (gdbarch, mips_skip_trampoline_code);
+ /* NOTE drow/2012-04-25: We overload the core solib trampoline code
+ to support MIPS16. This is a bad thing. Make sure not to do it
+ if we have an OS ABI that actually supports shared libraries, since
+ shared library support is more important. If we have an OS someday
+ that supports both shared libraries and MIPS16, we'll have to find
+ a better place for these.
+ macro/2012-04-25: But that applies to return trampolines only and
+ currently no MIPS OS ABI uses shared libraries that have them. */
+ set_gdbarch_in_solib_return_trampoline (gdbarch, mips_in_return_stub);
+
set_gdbarch_single_step_through_delay (gdbarch,
mips_single_step_through_delay);
projects / binutils.git / blobdiff