From a698d0d06fa53c237244835b97b5657f68a62add Mon Sep 17 00:00:00 2001 From: Jeff Law Date: Mon, 10 Feb 1997 23:56:56 +0000 Subject: [PATCH] * mn10200-tdep.c: Remove lots of debugging printfs, update/improve comments, formatting, etc. Plus other minor fixes for problems I found during my first pass over the mn10200 port. (mn10200_analyze_prologue): New function. (mn10200_frame_chain, mn10200_init_extra_frame_info): Use it. * config/mn10200/tm-mn10200.h: Lots of updates/improvements to comments, formatting, etc. Minor fixes for problems I found during my first pass over the mn10200 port. (TARGET_*_BIT): Define appropriately for ints, long longs, doubles and pointers. (REGISTER_VIRTUAL_TYPE): Define as a long. (EXTRACT_RETURN_VALUE): Rework to deal with long ints living in register pairs. (STORE_RETURN_VALUE): Similarly. Checking in my initial changes, prologue scanning, etc. Current gdb testsuite results: === gdb Summary === # of expected passes 3684 # of expected failures 40 # of unexpected failures 6 --- gdb/ChangeLog | 15 + gdb/config/mn10200/tm-mn10200.h | 103 ++++-- gdb/mn10200-tdep.c | 601 +++++++++++++++++++++++--------- 3 files changed, 535 insertions(+), 184 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9821f215418..173a0e55a30 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,20 @@ Mon Feb 10 16:11:57 1997 Jeffrey A Law (law@cygnus.com) + * mn10200-tdep.c: Remove lots of debugging printfs, update/improve + comments, formatting, etc. Plus other minor fixes for problems + I found during my first pass over the mn10200 port. + (mn10200_analyze_prologue): New function. + (mn10200_frame_chain, mn10200_init_extra_frame_info): Use it. + * config/mn10200/tm-mn10200.h: Lots of updates/improvements to + comments, formatting, etc. Minor fixes for problems I found during + my first pass over the mn10200 port. + (TARGET_*_BIT): Define appropriately for ints, long longs, doubles and + pointers. + (REGISTER_VIRTUAL_TYPE): Define as a long. + (EXTRACT_RETURN_VALUE): Rework to deal with long ints living + in register pairs. + (STORE_RETURN_VALUE): Similarly. + * blockframe.c (generic_get_saved_regs): Remove unused variable "addr". * breakpoint.c (frame_in_dummy): Move struct breakpoint *b decl diff --git a/gdb/config/mn10200/tm-mn10200.h b/gdb/config/mn10200/tm-mn10200.h index bba18101534..18910754bf3 100644 --- a/gdb/config/mn10200/tm-mn10200.h +++ b/gdb/config/mn10200/tm-mn10200.h @@ -19,9 +19,32 @@ 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. */ +/* The mn10200 is little endian. */ #define TARGET_BYTE_ORDER LITTLE_ENDIAN -/* 24 bit registers but we'll pretend that they are 32 bits */ +/* ints are only 16bits on the mn10200. */ +#undef TARGET_INT_BIT +#define TARGET_INT_BIT 16 + +/* The mn10200 doesn't support long long types. */ +#undef TARGET_LONG_LONG_BIT +#define TARGET_LONG_LONG_BIT 32 + +/* The mn10200 doesn't support double or long double either. */ +#undef TARGET_DOUBLE_BIT +#undef TARGET_LONG_DOUBLE_BIT +#define TARGET_DOUBLE_BIT 32 +#define TARGET_LONG_DOUBLE_BIT 32 + +/* Not strictly correct, but the machine independent code is not + ready to handle any of the basic sizes not being a power of two. */ +#undef TARGET_PTR_BIT +#define TARGET_PTR_BIT 32 + +/* The mn10200 really has 24 bit registers but the simulator reads/writes + them as 32bit values, so we claim they're 32bits each. This may have + to be tweaked if the Matsushita emulator/board really deals with them + as 24bits each. */ #define REGISTER_SIZE 4 #define MAX_REGISTER_RAW_SIZE REGISTER_SIZE @@ -39,7 +62,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define MDR_REGNUM 9 #define PSW_REGNUM 10 -#define REGISTER_VIRTUAL_TYPE(REG) builtin_type_int +/* Treat the registers as 32bit values. */ +#define REGISTER_VIRTUAL_TYPE(REG) builtin_type_long #define REGISTER_BYTE(REG) ((REG) * REGISTER_SIZE) #define REGISTER_VIRTUAL_SIZE(REG) REGISTER_SIZE @@ -47,16 +71,25 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define MAX_REGISTER_VIRTUAL_SIZE REGISTER_SIZE +/* The breakpoint instruction must be the same size as te smallest + instruction in the instruction set. + + The Matsushita mn10x00 processors have single byte instructions + so we need a single byte breakpoint. Matsushita hasn't defined + one, so we defined it ourselves. + + 0xff is the only available single byte insn left on the mn10200. */ #define BREAKPOINT {0xff} #define FUNCTION_START_OFFSET 0 #define DECR_PC_AFTER_BREAK 0 +/* Stacks grow the normal way. */ #define INNER_THAN < #define SAVED_PC_AFTER_CALL(frame) \ - read_memory_integer (read_register (SP_REGNUM), REGISTER_SIZE) + (read_memory_integer (read_register (SP_REGNUM), REGISTER_SIZE) & 0xffff) #ifdef __STDC__ struct frame_info; @@ -65,38 +98,66 @@ struct type; struct value; #endif -#define EXTRA_FRAME_INFO struct frame_saved_regs fsr; +#define EXTRA_FRAME_INFO struct frame_saved_regs fsr; int status; int stack_size; -extern void mn10200_init_extra_frame_info PARAMS ((struct frame_info *fi)); +extern void mn10200_init_extra_frame_info PARAMS ((struct frame_info *)); #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) mn10200_init_extra_frame_info (fi) -#define INIT_FRAME_PC /* Not necessary */ +#define INIT_FRAME_PC(x,y) -extern void mn10200_frame_find_saved_regs PARAMS ((struct frame_info *fi, struct frame_saved_regs *regaddr)); +extern void mn10200_frame_find_saved_regs PARAMS ((struct frame_info *, + struct frame_saved_regs *)); #define FRAME_FIND_SAVED_REGS(fi, regaddr) regaddr = fi->fsr -extern CORE_ADDR mn10200_frame_chain PARAMS ((struct frame_info *fi)); +extern CORE_ADDR mn10200_frame_chain PARAMS ((struct frame_info *)); #define FRAME_CHAIN(fi) mn10200_frame_chain (fi) #define FRAME_CHAIN_VALID(FP, FI) generic_frame_chain_valid (FP, FI) -extern CORE_ADDR mn10200_find_callers_reg PARAMS ((struct frame_info *fi, int regnum)); +extern CORE_ADDR mn10200_find_callers_reg PARAMS ((struct frame_info *, int)); extern CORE_ADDR mn10200_frame_saved_pc PARAMS ((struct frame_info *)); #define FRAME_SAVED_PC(FI) (mn10200_frame_saved_pc (FI)) /* Extract from an array REGBUF containing the (raw) register state a function return value of type TYPE, and copy that, in virtual format, - into VALBUF. */ + into VALBUF. */ #define EXTRACT_RETURN_VALUE(TYPE, REGBUF, VALBUF) \ - memcpy (VALBUF, REGBUF + REGISTER_BYTE (0), TYPE_LENGTH (TYPE)) + { \ + if (TYPE_LENGTH (TYPE) > 4) \ + abort (); \ + else if (TYPE_LENGTH (TYPE) > 2 && TYPE_CODE (TYPE) != TYPE_CODE_PTR) \ + { \ + memcpy (VALBUF, REGBUF + REGISTER_BYTE (0), 2); \ + memcpy (VALBUF, REGBUF + REGISTER_BYTE (1), 2); \ + } \ + else \ + { \ + memcpy (VALBUF, REGBUF + REGISTER_BYTE (0), TYPE_LENGTH (TYPE)); \ + } \ + } #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) \ extract_address (REGBUF + REGISTER_BYTE (0), \ REGISTER_RAW_SIZE (0)) #define STORE_RETURN_VALUE(TYPE, VALBUF) \ - write_register_bytes(REGISTER_BYTE (0), VALBUF, TYPE_LENGTH (TYPE)); - -extern CORE_ADDR mn10200_skip_prologue PARAMS ((CORE_ADDR pc)); + { \ + if (TYPE_LENGTH (TYPE) > 4) \ + abort (); \ + else if (TYPE_LENGTH (TYPE) > 2 && TYPE_CODE (TYPE) != TYPE_CODE_PTR) \ + { \ + write_register_bytes (REGISTER_BYTE (0), VALBUF, 2); \ + write_register_bytes (REGISTER_BYTE (1), VALBUF + 2, 2); \ + } \ + else \ + { \ + write_register_bytes (REGISTER_BYTE (0), VALBUF, TYPE_LENGTH (TYPE)); \ + } \ + } + +#define STORE_STRUCT_RETURN(STRUCT_ADDR, SP) write_register (0, STRUCT_ADDR); + + +extern CORE_ADDR mn10200_skip_prologue PARAMS ((CORE_ADDR)); #define SKIP_PROLOGUE(pc) pc = mn10200_skip_prologue (pc) #define FRAME_ARGS_SKIP 0 @@ -105,7 +166,7 @@ extern CORE_ADDR mn10200_skip_prologue PARAMS ((CORE_ADDR pc)); #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame) #define FRAME_NUM_ARGS(val, fi) ((val) = -1) -extern void mn10200_pop_frame PARAMS ((struct frame_info *frame)); +extern void mn10200_pop_frame PARAMS ((struct frame_info *)); #define POP_FRAME mn10200_pop_frame (get_current_frame ()) #define USE_GENERIC_DUMMY_FRAMES @@ -123,23 +184,19 @@ extern CORE_ADDR mn10200_push_return_address PARAMS ((CORE_ADDR, CORE_ADDR)); #define PUSH_DUMMY_FRAME generic_push_dummy_frame () extern CORE_ADDR -mn10200_push_arguments PARAMS ((int nargs, struct value **args, CORE_ADDR sp, - unsigned char struct_return, - CORE_ADDR struct_addr)); +mn10200_push_arguments PARAMS ((int, struct value **, CORE_ADDR, + unsigned char, CORE_ADDR)); #define PUSH_ARGUMENTS(NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR) \ (SP) = mn10200_push_arguments (NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR) -#define STORE_STRUCT_RETURN(STRUCT_ADDR, SP) - #define PC_IN_CALL_DUMMY(PC, SP, FP) generic_pc_in_call_dummy (PC, SP) #define USE_STRUCT_CONVENTION(GCC_P, TYPE) \ (TYPE_NFIELDS (TYPE) > 1 || TYPE_LENGTH (TYPE) > 4) -/* override the default get_saved_register function with - one that takes account of generic CALL_DUMMY frames */ +/* Override the default get_saved_register function with + one that takes account of generic CALL_DUMMY frames. */ #define GET_SAVED_REGISTER /* Define this for Wingdb */ - #define TARGET_MN10200 diff --git a/gdb/mn10200-tdep.c b/gdb/mn10200-tdep.c index a1f3a112c3d..11c03e9a089 100644 --- a/gdb/mn10200-tdep.c +++ b/gdb/mn10200-tdep.c @@ -28,122 +28,429 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "gdbcore.h" #include "symfile.h" -/* Info gleaned from scanning a function's prologue. */ - -struct pifsr /* Info about one saved reg */ +/* The main purpose of this file is dealing with prologues to extract + information about stack frames and saved registers. + + For reference here's how prologues look on the mn10200: + + With frame pointer: + mov fp,a0 + mov sp,fp + add ,sp + Register saves for d2, d3, a3 as needed. Saves start + at fp - and work towards higher addresses. Note + that the saves are actually done off the stack pointer + in the prologue! This makes for smaller code and easier + prologue scanning as the displacement fields will never + be more than 8 bits! + + Without frame pointer: + add ,sp + Register saves for d2, d3, a3 as needed. Saves start + at sp and work towards higher addresses. + + + One day we might keep the stack pointer constant, that won't + change the code for prologues, but it will make the frame + pointerless case much more common. */ + +/* Analyze the prologue to determine where registers are saved, + the end of the prologue, etc etc. Return the end of the prologue + scanned. + + We store into FI (if non-null) several tidbits of information: + + * stack_size -- size of this stack frame. Note that if we stop in + certain parts of the prologue/epilogue we may claim the size of the + current frame is zero. This happens when the current frame has + not been allocated yet or has already been deallocated. + + * fsr -- Addresses of registers saved in the stack by this frame. + + * status -- A (relatively) generic status indicator. It's a bitmask + with the following bits: + + MY_FRAME_IN_SP: The base of the current frame is actually in + the stack pointer. This can happen for frame pointerless + functions, or cases where we're stopped in the prologue/epilogue + itself. For these cases mn10200_analyze_prologue will need up + update fi->frame before returning or analyzing the register + save instructions. + + MY_FRAME_IN_FP: The base of the current frame is in the + frame pointer register ($a2). + + CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily + in $a0. This can happen if we're stopped in the prologue. + + NO_MORE_FRAMES: Set this if the current frame is "start" or + if the first instruction looks like mov ,sp. This tells + frame chain to not bother trying to unwind past this frame. */ + +#define MY_FRAME_IN_SP 0x1 +#define MY_FRAME_IN_FP 0x2 +#define CALLER_A2_IN_A0 0x4 +#define NO_MORE_FRAMES 0x8 + +static CORE_ADDR +mn10200_analyze_prologue (fi, pc) + struct frame_info *fi; + CORE_ADDR pc; { - int framereg; /* Frame reg (SP or FP) */ - int offset; /* Offset from framereg */ - int reg; /* Saved register number */ -}; + CORE_ADDR func_addr, func_end, addr, stop; + CORE_ADDR stack_size; + unsigned char buf[4]; + int status; + char *name; + + /* Use the PC in the frame if it's provided to look up the + start of this function. */ + pc = (fi ? fi->pc : pc); + + /* Find the start of this function. */ + status = find_pc_partial_function (pc, &name, &func_addr, &func_end); + + /* Do nothing if we couldn't find the start of this function or if we're + stopped at the first instruction in the prologue. */ + if (status == 0) + return pc; + + /* If we're in start, then give up. */ + if (strcmp (name, "start") == 0) + { + fi->status = NO_MORE_FRAMES; + return pc; + } -struct prologue_info -{ - int framereg; - int frameoffset; - int start_function; - struct pifsr *pifsrs; -}; + /* At the start of a function our frame is in the stack pointer. */ + if (fi) + fi->status = MY_FRAME_IN_SP; -/* Function: frame_chain - Figure out and return the caller's frame pointer given current - frame_info struct. + /* If we're physically on an RTS instruction, then our frame has already + been deallocated. - We start out knowing the current pc, current sp, current fp. - We want to determine the caller's fp and caller's pc. To do this - correctly, we have to be able to handle the case where we are in the - middle of the prologue which involves scanning the prologue. + fi->frame is bogus, we need to fix it. */ + if (fi && fi->pc + 1 == func_end) + { + status = target_read_memory (fi->pc, buf, 1); + if (status != 0) + { + fi->frame = read_sp (); + return fi->pc; + } - We don't handle dummy frames yet but we would probably just return the - stack pointer that was in use at the time the function call was made? -*/ + if (buf[0] == 0xfe) + { + fi->frame = read_sp (); + return fi->pc; + } + } -CORE_ADDR -mn10200_frame_chain (fi) - struct frame_info *fi; -{ - struct prologue_info pi; - CORE_ADDR callers_pc, callers_fp, curr_sp; - CORE_ADDR past_prologue_addr; - int past_prologue = 1; /* default to being past prologue */ - int n_movm_args = 4; - - struct pifsr *pifsr, *pifsr_tmp; - - /* current pc is fi->pc */ - /* current fp is fi->frame */ - /* current sp is: */ - curr_sp = read_register (SP_REGNUM); - -/* - printf("curr pc = 0x%x ; curr fp = 0x%x ; curr sp = 0x%x\n", - fi->pc, fi->frame, curr_sp); -*/ - - /* first inst after prologue is: */ - past_prologue_addr = mn10200_skip_prologue (fi->pc); - - /* Are we in the prologue? */ - /* Yes if mn10200_skip_prologue returns an address after the - current pc in which case we have to scan prologue */ - if (fi->pc < mn10200_skip_prologue (fi->pc)) - past_prologue = 0; - - /* scan prologue if we're not past it */ - if (!past_prologue) + /* Similarly if we're stopped on the first insn of a prologue as our + frame hasn't been allocated yet. */ + if (fi && fi->pc == func_addr) + { + fi->frame = read_sp (); + return fi->pc; + } + + /* Figure out where to stop scanning. */ + stop = fi ? fi->pc : func_end; + + /* Don't walk off the end of the function. */ + stop = stop > func_end ? func_end : stop; + + /* Start scanning on the first instruction of this function. */ + addr = func_addr; + + status = target_read_memory (addr, buf, 2); + if (status != 0) { - /* printf("scanning prologue\n"); */ - /* FIXME -- fill out this case later */ - return 0x0; /* bogus value */ + if (fi && fi->status & MY_FRAME_IN_SP) + fi->frame = read_sp (); + return addr; } - if (past_prologue) /* if we don't need to scan the prologue */ + /* First see if this insn sets the stack pointer; if so, it's something + we won't understand, so quit now. */ + if (buf[0] == 0xdf + || (buf[0] == 0xf4 && buf[1] == 0x77)) + { + if (fi) + fi->status = NO_MORE_FRAMES; + return addr; + } + + /* Now see if we have a frame pointer. + + Search for mov a2,a0 (0xf278) + then mov a3,a2 (0xf27e). */ + + if (buf[0] == 0xf2 && buf[1] == 0x78) + { + /* Our caller's $a2 will be found in $a0 now. Note it for + our callers. */ + if (fi) + fi->status |= CALLER_A2_IN_A0; + addr += 2; + if (addr >= stop) + { + /* We still haven't allocated our local stack. Handle this + as if we stopped on the first or last insn of a function. */ + if (fi) + fi->frame = read_sp (); + return addr; + } + + status = target_read_memory (addr, buf, 2); + if (status != 0) + { + if (fi) + fi->frame = read_sp (); + return addr; + } + if (buf[0] == 0xf2 && buf[1] == 0x7e) + { + addr += 2; + + /* Our frame pointer is valid now. */ + if (fi) + { + fi->status |= MY_FRAME_IN_FP; + fi->status &= ~MY_FRAME_IN_SP; + } + if (addr >= stop) + return addr; + } + else + { + if (fi) + fi->frame = read_sp (); + return addr; + } + } + + /* Next we should allocate the local frame. + + Search for add imm8,a3 (0xd3XX) + or add imm16,a3 (0xf70bXXXX) + or add imm24,a3 (0xf467XXXXXX). + + If none of the above was found, then this prologue has + no stack, and therefore can't have any register saves, + so quit now. */ + status = target_read_memory (addr, buf, 2); + if (status != 0) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp (); + return addr; + } + if (buf[0] == 0xd3) + { + stack_size = extract_signed_integer (&buf[1], 1); + if (fi) + fi->stack_size = stack_size; + addr += 2; + if (addr >= stop) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp () + stack_size; + return addr; + } + } + else if (buf[0] == 0xf7 && buf[1] == 0x0b) + { + status = target_read_memory (addr + 2, buf, 2); + if (status != 0) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp (); + return addr; + } + stack_size = extract_signed_integer (buf, 2); + if (fi) + fi->stack_size = stack_size; + addr += 4; + if (addr >= stop) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp () + stack_size; + return addr; + } + } + else if (buf[0] == 0xf4 && buf[1] == 0x67) + { + status = target_read_memory (addr + 2, buf, 3); + if (status != 0) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp (); + return addr; + } + stack_size = extract_signed_integer (buf, 3); + if (fi) + fi->stack_size = stack_size; + addr += 5; + if (addr >= stop) + { + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp () + stack_size; + return addr; + } + } + else { - callers_pc = fi->frame - REGISTER_SIZE; - callers_fp = fi->frame - (4 * REGISTER_SIZE); - -#if 0 - printf("callers_pc = 0x%x ; callers_fp = 0x%x\n", - callers_pc, callers_fp); - printf("*callers_pc = 0x%x ; *callers_fp = 0x%x\n", - read_memory_integer(callers_pc, REGISTER_SIZE), - read_memory_integer(callers_fp, REGISTER_SIZE)); -#endif - - return read_memory_integer(callers_fp, REGISTER_SIZE); + if (fi && (fi->status & MY_FRAME_IN_SP)) + fi->frame = read_sp (); + return addr; } - /* we don't get here */ + /* At this point fi->frame needs to be correct. + + If MY_FRAME_IN_SP is set, then we need to fix fi->frame so + that backtracing, find_frame_saved_regs, etc work correctly. */ + if (fi && (fi->status & MY_FRAME_IN_SP) != 0) + fi->frame = read_sp () - fi->stack_size; + + /* And last we have the register saves. These are relatively + simple because they're physically done off the stack pointer, + and thus the number of different instructions we need to + check is greatly reduced because we know the displacements + will be small. + + Search for movx d2,(X,a3) (0xf55eXX) + then movx d3,(X,a3) (0xf55fXX) + then mov a2,(X,a3) (0x5eXX) No frame pointer case + or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ + + status = target_read_memory (addr, buf, 2); + if (status != 0) + return addr; + if (buf[0] == 0xf5 && buf[1] == 0x5e) + { + if (fi) + { + status = target_read_memory (addr + 2, buf, 1); + if (status != 0) + return addr; + fi->fsr.regs[2] = (fi->frame + stack_size + + extract_signed_integer (buf, 1)); + } + addr += 3; + if (addr >= stop) + return addr; + status = target_read_memory (addr, buf, 2); + if (status != 0) + return addr; + } + if (buf[0] == 0xf5 && buf[1] == 0x5f) + { + if (fi) + { + status = target_read_memory (addr + 2, buf, 1); + if (status != 0) + return addr; + fi->fsr.regs[3] = (fi->frame + stack_size + + extract_signed_integer (buf, 1)); + } + addr += 3; + if (addr >= stop) + return addr; + status = target_read_memory (addr, buf, 2); + if (status != 0) + return addr; + } + if (buf[0] == 0x5e || buf[0] == 0x5c) + { + if (fi) + { + status = target_read_memory (addr + 1, buf, 1); + if (status != 0) + return addr; + fi->fsr.regs[6] = (fi->frame + stack_size + + extract_signed_integer (buf, 1)); + fi->status &= ~CALLER_A2_IN_A0; + } + addr += 2; + if (addr >= stop) + return addr; + return addr; + } + return addr; } + +/* Function: frame_chain + Figure out and return the caller's frame pointer given current + frame_info struct. -/* Function: find_callers_reg - Find REGNUM on the stack. Otherwise, it's in an active register. - One thing we might want to do here is to check REGNUM against the - clobber mask, and somehow flag it as invalid if it isn't saved on - the stack somewhere. This would provide a graceful failure mode - when trying to get the value of caller-saves registers for an inner - frame. */ + We don't handle dummy frames yet but we would probably just return the + stack pointer that was in use at the time the function call was made? */ CORE_ADDR -mn10200_find_callers_reg (fi, regnum) +mn10200_frame_chain (fi) struct frame_info *fi; - int regnum; { -/* printf("mn10200_find_callers_reg\n"); */ + struct frame_info dummy_frame; + + /* Walk through the prologue to determine the stack size, + location of saved registers, end of the prologue, etc. */ + if (fi->status == 0) + mn10200_analyze_prologue (fi, (CORE_ADDR)0); + + /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ + if (fi->status & NO_MORE_FRAMES) + return 0; + + /* Now that we've analyzed our prologue, determine the frame + pointer for our caller. + + If our caller has a frame pointer, then we need to + find the entry value of $a2 to our function. + + If CALLER_A2_IN_A0, then the chain is in $a0. + + If fsr.regs[6] is nonzero, then it's at the memory + location pointed to by fsr.regs[6]. + + Else it's still in $a2. - for (; fi; fi = fi->next) - if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) - return generic_read_register_dummy (fi->pc, fi->frame, regnum); - else if (fi->fsr.regs[regnum] != 0) - return read_memory_unsigned_integer (fi->fsr.regs[regnum], - REGISTER_RAW_SIZE(regnum)); + If our caller does not have a frame pointer, then his + frame base is fi->frame + caller's stack size + 4. */ + + /* The easiest way to get that info is to analyze our caller's frame. - return read_register (regnum); + So we set up a dummy frame and call mn10200_analyze_prologue to + find stuff for us. */ + dummy_frame.pc = FRAME_SAVED_PC (fi); + dummy_frame.frame = fi->frame; + memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); + dummy_frame.status = 0; + dummy_frame.stack_size = 0; + mn10200_analyze_prologue (&dummy_frame); + + if (dummy_frame.status & MY_FRAME_IN_FP) + { + /* Our caller has a frame pointer. So find the frame in $a2, $a0, + or in the stack. */ + if (fi->fsr.regs[6]) + return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) + & 0xffffff); + else if (fi->status & CALLER_A2_IN_A0) + return read_register (4); + else + return read_register (FP_REGNUM); + } + else + { + /* Our caller does not have a frame pointer. So his frame starts + at the base of our frame (fi->frame) + + 4 (saved pc). */ + return fi->frame + dummy_frame.stack_size + 4; + } } /* Function: skip_prologue - Return the address of the first inst past the prologue of the function. -*/ + Return the address of the first inst past the prologue of the function. */ CORE_ADDR mn10200_skip_prologue (pc) @@ -151,10 +458,8 @@ mn10200_skip_prologue (pc) { CORE_ADDR func_addr, func_end; -/* printf("mn10200_skip_prologue\n"); */ - - /* See what the symbol table says */ - + /* First check the symbol table. That'll be faster than scanning + the prologue instructions if we have debug sybmols. */ if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) { struct symtab_and_line sal; @@ -163,14 +468,11 @@ mn10200_skip_prologue (pc) if (sal.line != 0 && sal.end < func_end) return sal.end; - else - /* Either there's no line info, or the line after the prologue is after - the end of the function. In this case, there probably isn't a - prologue. */ - return pc; + + return mn10200_analyze_prologue (NULL, pc); } -/* We can't find the start of this function, so there's nothing we can do. */ + /* We couldn't find the start of this function, do nothing. */ return pc; } @@ -184,32 +486,36 @@ mn10200_pop_frame (frame) { int regnum; -/* printf("mn10200_pop_frame start\n"); */ - if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) generic_pop_dummy_frame (); else { write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); + /* Restore any saved registers. */ for (regnum = 0; regnum < NUM_REGS; regnum++) if (frame->fsr.regs[regnum] != 0) - write_register (regnum, - read_memory_unsigned_integer (frame->fsr.regs[regnum], - REGISTER_RAW_SIZE(regnum))); + { + ULONGEST value; + + value = read_memory_unsigned_integer (frame->fsr.regs[regnum], + REGISTER_RAW_SIZE (regnum)); + write_register (regnum, value); + } + /* Actually cut back the stack. */ write_register (SP_REGNUM, FRAME_FP (frame)); + + /* Don't we need to set the PC?!? XXX FIXME. */ } + /* Throw away any cached frame information. */ flush_cached_frames (); - -/* printf("mn10200_pop_frame end\n"); */ } /* Function: push_arguments Setup arguments for a call to the target. Arguments go in - order on the stack. -*/ + order on the stack. */ CORE_ADDR mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) @@ -221,17 +527,20 @@ mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) { int argnum = 0; int len = 0; - int stack_offset = 0; /* copy args to this offset onto stack */ - -/* printf("mn10200_push_arguments start\n"); */ + int stack_offset = 0; - /* First, just for safety, make sure stack is aligned */ + /* This should be a nop, but align the stack just in case something + went wrong. */ sp &= ~3; - /* Now make space on the stack for the args. */ + /* Now make space on the stack for the args. + + XXX This doesn't appear to handle pass-by-invisible reference + arguments. */ for (argnum = 0; argnum < nargs; argnum++) - len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3); + len += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3); + /* Allocate stack space. */ sp -= len; /* Push all arguments onto the stack. */ @@ -240,10 +549,12 @@ mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) int len; char *val; + /* XXX Check this. What about UNIONS? Size check looks + wrong too. */ if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) { - /* for now, pretend structs aren't special */ + /* XXX Wrong, we want a pointer to this argument. */ len = TYPE_LENGTH (VALUE_TYPE (*args)); val = (char *)VALUE_CONTENTS (*args); } @@ -255,6 +566,7 @@ mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) while (len > 0) { + /* XXX This looks wrong; we can have one and two byte args. */ write_memory (sp + stack_offset, val, 4); len -= 4; @@ -264,8 +576,6 @@ mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) args++; } -/* printf"mn10200_push_arguments end\n"); */ - return sp; } @@ -278,9 +588,7 @@ mn10200_push_return_address (pc, sp) CORE_ADDR pc; CORE_ADDR sp; { -/* printf("mn10200_push_return_address\n"); */ - /* write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); */ return sp; } @@ -295,9 +603,8 @@ CORE_ADDR mn10200_frame_saved_pc (fi) struct frame_info *fi; { -/* printf("mn10200_frame_saved_pc\n"); */ - - return (read_memory_integer(fi->frame - REGISTER_SIZE, REGISTER_SIZE)); + /* The saved PC will always be at the base of the current frame. */ + return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); } void @@ -309,69 +616,41 @@ get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) int regnum; enum lval_type *lval; { -/* printf("get_saved_register\n"); */ - generic_get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval); } /* Function: init_extra_frame_info Setup the frame's frame pointer, pc, and frame addresses for saved - registers. Most of the work is done in frame_chain(). + registers. Most of the work is done in mn10200_analyze_prologue(). Note that when we are called for the last frame (currently active frame), that fi->pc and fi->frame will already be setup. However, fi->frame will be valid only if this routine uses FP. For previous frames, fi-frame will - always be correct (since that is derived from v850_frame_chain ()). + always be correct. mn10200_analyze_prologue will fix fi->frame if + it's not valid. We can be called with the PC in the call dummy under two circumstances. First, during normal backtracing, second, while figuring out the frame - pointer just prior to calling the target function (see run_stack_dummy). -*/ + pointer just prior to calling the target function (see run_stack_dummy). */ void mn10200_init_extra_frame_info (fi) struct frame_info *fi; { - struct prologue_info pi; - struct pifsr pifsrs[NUM_REGS + 1], *pifsr; - int reg; - if (fi->next) fi->pc = FRAME_SAVED_PC (fi->next); memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); + fi->status = 0; + fi->stack_size = 0; - /* The call dummy doesn't save any registers on the stack, so we can return - now. */ -/* - if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) - return; - - pi.pifsrs = pifsrs; -*/ - - /* v850_scan_prologue (fi->pc, &pi); */ -/* - if (!fi->next && pi.framereg == SP_REGNUM) - fi->frame = read_register (pi.framereg) - pi.frameoffset; - - for (pifsr = pifsrs; pifsr->framereg; pifsr++) - { - fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame; - - if (pifsr->framereg == SP_REGNUM) - fi->fsr.regs[pifsr->reg] += pi.frameoffset; - } -*/ -/* printf("init_extra_frame_info\n"); */ + mn10200_analyze_prologue (fi, 0); } void _initialize_mn10200_tdep () { -/* printf("_initialize_mn10200_tdep\n"); */ - tm_print_insn = print_insn_mn10200; } -- 2.30.2