X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fmem-break.c;h=9cf638e4c62c8919cdeccd407c77a65a1841b91d;hb=a8cdafbd4e8dbf81a28d98de6a046bd9bc5cc097;hp=7e55233e168263e0e2c2c0db508e8e50e07dda6e;hpb=fa803dc60f0bf01297674c41d001798e18ade4dc;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/mem-break.c b/gdb/mem-break.c index 7e55233e16..9cf638e4c6 100644 --- a/gdb/mem-break.c +++ b/gdb/mem-break.c @@ -1,102 +1,135 @@ /* Simulate breakpoints by patching locations in the target system, for GDB. - Copyright 1990, 1991 Free Software Foundation, Inc. + + Copyright 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, + 2002 Free Software Foundation, Inc. + Contributed by Cygnus Support. Written by John Gilmore. -This file is part of GDB. + 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 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. + 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ + 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" -#ifdef BREAKPOINT /* This file is only useful if BREAKPOINT is set. If not, we punt. */ -#include +#include "symtab.h" #include "breakpoint.h" #include "inferior.h" #include "target.h" -/* This is the sequence of bytes we insert for a breakpoint. On some - machines, breakpoints are handled by the target environment and we - don't have to worry about them here. */ -static char break_insn[] = BREAKPOINT; +/* Use the program counter to determine the contents and size + of a breakpoint instruction. If no target-dependent macro + BREAKPOINT_FROM_PC has been defined to implement this function, + assume that the breakpoint doesn't depend on the PC, and + use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros. + Return a pointer to a string of bytes that encode a breakpoint + instruction, stores the length of the string to *lenptr, + and optionally adjust the pc to point to the correct memory location + for inserting the breakpoint. */ -/* This is only to check that BREAKPOINT fits in BREAKPOINT_MAX bytes. */ +const unsigned char * +memory_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) +{ + /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a + breakpoint. On some machines, breakpoints are handled by the + target environment and we don't have to worry about them here. */ +#ifdef BIG_BREAKPOINT + if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) + { + static unsigned char big_break_insn[] = BIG_BREAKPOINT; + *lenptr = sizeof (big_break_insn); + return big_break_insn; + } +#endif +#ifdef LITTLE_BREAKPOINT + if (TARGET_BYTE_ORDER != BFD_ENDIAN_BIG) + { + static unsigned char little_break_insn[] = LITTLE_BREAKPOINT; + *lenptr = sizeof (little_break_insn); + return little_break_insn; + } +#endif +#ifdef BREAKPOINT + { + static unsigned char break_insn[] = BREAKPOINT; + *lenptr = sizeof (break_insn); + return break_insn; + } +#endif + *lenptr = 0; + return NULL; +} -static char check_break_insn_size[BREAKPOINT_MAX] = BREAKPOINT; -/* Insert a breakpoint on machines that don't have any better breakpoint +/* Insert a breakpoint on targets that don't have any better breakpoint support. We read the contents of the target location and stash it, then overwrite it with a breakpoint instruction. ADDR is the target location in the target machine. CONTENTS_CACHE is a pointer to memory allocated for saving the target contents. It is guaranteed - by the caller to be long enough to save sizeof BREAKPOINT bytes. - FIXME: This size is target_arch dependent and should be available in - the target_arch transfer vector, if we ever have one... */ + by the caller to be long enough to save BREAKPOINT_LEN bytes (this + is accomplished via BREAKPOINT_MAX). */ int -memory_insert_breakpoint (addr, contents_cache) - CORE_ADDR addr; - char *contents_cache; +default_memory_insert_breakpoint (CORE_ADDR addr, char *contents_cache) { int val; + const unsigned char *bp; + int bplen; + + /* Determine appropriate breakpoint contents and size for this address. */ + bp = BREAKPOINT_FROM_PC (&addr, &bplen); + if (bp == NULL) + error ("Software breakpoints not implemented for this target."); - val = target_read_memory (addr, contents_cache, sizeof break_insn); + /* Save the memory contents. */ + val = target_read_memory (addr, contents_cache, bplen); + /* Write the breakpoint. */ if (val == 0) - val = target_write_memory (addr, break_insn, sizeof break_insn); + val = target_write_memory (addr, (char *) bp, bplen); return val; } int -memory_remove_breakpoint (addr, contents_cache) - CORE_ADDR addr; - char *contents_cache; +default_memory_remove_breakpoint (CORE_ADDR addr, char *contents_cache) { - return target_write_memory (addr, contents_cache, sizeof break_insn); -} - - -int memory_breakpoint_size = sizeof (break_insn); + const unsigned char *bp; + int bplen; + /* Determine appropriate breakpoint contents and size for this address. */ + bp = BREAKPOINT_FROM_PC (&addr, &bplen); + if (bp == NULL) + error ("Software breakpoints not implemented for this target."); -#else /* BREAKPOINT */ + return target_write_memory (addr, contents_cache, bplen); +} -char nogo[] = "Breakpoints not implemented for this target."; int -memory_insert_breakpoint (addr, contents_cache) - CORE_ADDR addr; - char *contents_cache; +memory_insert_breakpoint (CORE_ADDR addr, char *contents_cache) { - error (nogo); - return 0; /* lint */ + return MEMORY_INSERT_BREAKPOINT(addr, contents_cache); } int -memory_remove_breakpoint (addr, contents_cache) - CORE_ADDR addr; - char *contents_cache; +memory_remove_breakpoint (CORE_ADDR addr, char *contents_cache) { - error (nogo); - return 0; /* lint */ + return MEMORY_REMOVE_BREAKPOINT(addr, contents_cache); } - -int memory_breakpoint_size = -1; - -#endif /* BREAKPOINT */