/* Common target dependent code for GDB on ARM systems.
- Copyright 1988, 1989, 1991, 1992, 1993, 1995-1999
+ Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1997, 1998, 1999, 2000
Free Software Foundation, Inc.
This file is part of GDB.
#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
/* Default register names as specified by APCS. */
-static char *apcs_register_names[] =
+static char * atpcs_register_names[] =
{"a1", "a2", "a3", "a4", /* 0 1 2 3 */
"v1", "v2", "v3", "v4", /* 4 5 6 7 */
- "v5", "v6", "sl", "fp", /* 8 9 10 11 */
- "ip", "sp", "lr", "pc", /* 12 13 14 15 */
+ "v5", "v6", "v7", "v8", /* 8 9 10 11 */
+ "IP", "SP", "LR", "PC", /* 12 13 14 15 */
"f0", "f1", "f2", "f3", /* 16 17 18 19 */
"f4", "f5", "f6", "f7", /* 20 21 22 23 */
- "fps", "ps"} /* 24 25 */ ;
+ "FPS", "PS" }; /* 24 25 */
/* Alternate set of registers names used by GCC. */
-static char *additional_register_names[] =
-{"r0", "r1", "r2", "r3", /* 0 1 2 3 */
- "r4", "r5", "r6", "r7", /* 4 5 6 7 */
- "r8", "r9", "r10", "r11", /* 8 9 10 11 */
- "r12", "r13", "r14", "pc", /* 12 13 14 15 */
- "f0", "f1", "f2", "f3", /* 16 17 18 19 */
- "f4", "f5", "f6", "f7", /* 20 21 22 23 */
- "fps", "ps"} /* 24 25 */ ;
+static char * additional_register_names[] =
+{"r0", "r1", "r2", "r3", /* 0 1 2 3 */
+ "r4", "r5", "r6", "r7", /* 4 5 6 7 */
+ "r8", "r9", "r10", "r11", /* 8 9 10 11 */
+ "r12", "sp", "lr", "pc", /* 12 13 14 15 */
+ "f0", "f1", "f2", "f3", /* 16 17 18 19 */
+ "f4", "f5", "f6", "f7", /* 20 21 22 23 */
+ "fps", "ps" }; /* 24 25 */
/* This is the variable that is set with "set disassembly-flavor".
By default use the APCS registers names. */
-char **arm_register_names = apcs_register_names;
+char ** arm_register_names = atpcs_register_names;
/* Valid register name flavours. */
static char apcs_flavor[] = "apcs";
static char r_prefix_flavor[] = "r-prefix";
-static char *valid_flavors[] =
+static char * valid_flavors[] =
{
apcs_flavor,
r_prefix_flavor,
add sp, sp, #-28
add r7, sp, #12
Sometimes the latter instruction may be replaced by:
- mov r7, sp
+ mov r7, sp
+
+ or like this:
+ push {r7, lr}
+ mov r7, sp
+ sub sp, #12
+
+ or, on tpcs, like this:
+ sub sp,#16
+ push {r7, lr}
+ (many instructions)
+ mov r7, sp
+ sub sp, #12
+
+ There is always one instruction of three classes:
+ 1 - push
+ 2 - setting of r7
+ 3 - adjusting of sp
+
+ When we have found at least one of each class we are done with the prolog.
+ Note that the "sub sp, #NN" before the push does not count.
*/
static CORE_ADDR
thumb_skip_prologue (CORE_ADDR pc)
{
CORE_ADDR current_pc;
+ int findmask = 0; /* findmask:
+ bit 0 - push { rlist }
+ bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
+ bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
+ */
- for (current_pc = pc; current_pc < pc + 20; current_pc += 2)
+ for (current_pc = pc; current_pc < pc + 40; current_pc += 2)
{
unsigned short insn = read_memory_unsigned_integer (current_pc, 2);
- if ((insn & 0xfe00) != 0xb400 /* push {..., r7, lr} */
- && (insn & 0xff00) != 0xb000 /* add sp, #simm */
- && (insn & 0xff00) != 0xaf00 /* add r7, sp, #imm */
- && insn != 0x466f /* mov r7, sp */
- && (insn & 0xffc0) != 0x4640) /* mov r0-r7, r8-r15 */
- break;
+ if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
+ {
+ findmask |= 1; /* push found */
+ }
+ else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
+ {
+ if ((findmask & 1) == 0) /* before push ? */
+ continue;
+ else
+ findmask |= 4; /* add/sub sp found */
+ }
+ else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
+ {
+ findmask |= 2; /* setting of r7 found */
+ }
+ else if (insn == 0x466f) /* mov r7, sp */
+ {
+ findmask |= 2; /* setting of r7 found */
+ }
+ else
+ continue; /* something in the prolog that we don't care about or some
+ instruction from outside the prolog scheduled here for optimization */
}
return current_pc;
4) the offset from the stack pointer to the frame pointer
This information is stored in the "extra" fields of the frame_info.
- A typical Thumb function prologue might look like this:
- push {r7, lr}
- sub sp, #28,
- add r7, sp, #12
- Which would create this stack frame (offsets relative to FP)
+ A typical Thumb function prologue would create this stack frame
+ (offsets relative to FP)
old SP -> 24 stack parameters
20 LR
16 R7
R7 -> 0 local variables (16 bytes)
SP -> -12 additional stack space (12 bytes)
The frame size would thus be 36 bytes, and the frame offset would be
- 12 bytes. The frame register is R7. */
+ 12 bytes. The frame register is R7.
+
+ The comments for thumb_skip_prolog() describe the algorithm we use to detect
+ the end of the prolog */
/* *INDENT-ON* */
static void
CORE_ADDR prologue_end;
CORE_ADDR current_pc;
int saved_reg[16]; /* which register has been copied to register n? */
+ int findmask = 0; /* findmask:
+ bit 0 - push { rlist }
+ bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
+ bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
+ */
int i;
if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
saved_reg[i] = i;
/* Search the prologue looking for instructions that set up the
- frame pointer, adjust the stack pointer, and save registers. */
+ frame pointer, adjust the stack pointer, and save registers.
+ Do this until all basic prolog instructions are found. */
fi->framesize = 0;
- for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
+ for (current_pc = prologue_start;
+ (current_pc < prologue_end) && ((findmask & 7) != 7);
+ current_pc += 2)
{
unsigned short insn;
int regno;
if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
{
+ int mask;
+ findmask |= 1; /* push found */
/* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
whether to save LR (R14). */
- int mask = (insn & 0xff) | ((insn & 0x100) << 6);
+ mask = (insn & 0xff) | ((insn & 0x100) << 6);
/* Calculate offsets of saved R0-R7 and LR. */
for (regno = LR_REGNUM; regno >= 0; regno--)
saved_reg[regno] = regno; /* reset saved register map */
}
}
- else if ((insn & 0xff00) == 0xb000) /* add sp, #simm */
+ else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
{
+ if ((findmask & 1) == 0) /* before push ? */
+ continue;
+ else
+ findmask |= 4; /* add/sub sp found */
+
offset = (insn & 0x7f) << 2; /* get scaled offset */
- if (insn & 0x80) /* is it signed? */
- offset = -offset;
+ if (insn & 0x80) /* is it signed? (==subtracting) */
+ {
+ fi->frameoffset += offset;
+ offset = -offset;
+ }
fi->framesize -= offset;
}
else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
{
+ findmask |= 2; /* setting of r7 found */
fi->framereg = THUMB_FP_REGNUM;
fi->frameoffset = (insn & 0xff) << 2; /* get scaled offset */
}
- else if (insn == 0x466f) /* mov r7, sp */
+ else if (insn == 0x466f) /* mov r7, sp */
{
+ findmask |= 2; /* setting of r7 found */
fi->framereg = THUMB_FP_REGNUM;
fi->frameoffset = 0;
saved_reg[THUMB_FP_REGNUM] = SP_REGNUM;
saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */
}
else
- break; /* anything else isn't prologue */
+ continue; /* something in the prolog that we don't care about or some
+ instruction from outside the prolog scheduled here for optimization */
}
}
val = (char *) &dbl_arg;
len = sizeof (double);
}
-#if 0
+#if 1
+ /* I don't know why this code was disable. The only logical use
+ for a function pointer is to call that function, so setting
+ the mode bit is perfectly fine. FN */
/* If the argument is a pointer to a function, and it is a Thumb
function, set the low bit of the pointer. */
if (TYPE_CODE_PTR == typecode
{
if (disassembly_flavor == apcs_flavor)
{
- if (arm_toggle_regnames () == 0)
- arm_toggle_regnames ();
- arm_register_names = apcs_register_names;
+ parse_arm_disassembler_option ("reg-names-atpcs");
+ arm_register_names = atpcs_register_names;
}
else if (disassembly_flavor == r_prefix_flavor)
{
- if (arm_toggle_regnames () == 1)
- arm_toggle_regnames ();
+ parse_arm_disassembler_option ("reg-names-std");
arm_register_names = additional_register_names;
}
}
tm_print_insn = gdb_print_insn_arm;
/* Sync the opcode insn printer with our register viewer: */
-
- if (arm_toggle_regnames () != 1)
- arm_toggle_regnames ();
+ parse_arm_disassembler_option ("reg-names-atpcs");
/* Add the deprecated "othernames" command */
projects / deliverable / binutils-gdb.git / blobdiff