/* Target-dependent code for HPUX running on PA-RISC, for GDB. Copyright 2002, 2003 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 "arch-utils.h" #include "gdbcore.h" #include "osabi.h" #include "gdb_string.h" #include "frame.h" #include "symtab.h" #include "objfiles.h" #include "inferior.h" #include "infcall.h" #include "hppa-tdep.h" #include #include /* Forward declarations. */ extern void _initialize_hppa_hpux_tdep (void); extern initialize_file_ftype _initialize_hppa_hpux_tdep; typedef struct { struct minimal_symbol *msym; CORE_ADDR solib_handle; CORE_ADDR return_val; } args_for_find_stub; /* FIXME: brobecker 2002-12-25. The following functions will eventually become static, after the multiarching conversion is done. */ int hppa_hpux_pc_in_sigtramp (CORE_ADDR pc, char *name); void hppa32_hpux_frame_saved_pc_in_sigtramp (struct frame_info *fi, CORE_ADDR *tmp); void hppa32_hpux_frame_base_before_sigtramp (struct frame_info *fi, CORE_ADDR *tmp); void hppa32_hpux_frame_find_saved_regs_in_sigtramp (struct frame_info *fi, CORE_ADDR *fsr); void hppa64_hpux_frame_saved_pc_in_sigtramp (struct frame_info *fi, CORE_ADDR *tmp); void hppa64_hpux_frame_base_before_sigtramp (struct frame_info *fi, CORE_ADDR *tmp); void hppa64_hpux_frame_find_saved_regs_in_sigtramp (struct frame_info *fi, CORE_ADDR *fsr); int hppa_hpux_pc_in_sigtramp (CORE_ADDR pc, char *name) { /* Actually, for a PA running HPUX the kernel calls the signal handler without an intermediate trampoline. Luckily the kernel always sets the return pointer for the signal handler to point to _sigreturn. */ return (name && (strcmp ("_sigreturn", name) == 0)); } /* For hppa32_hpux_frame_saved_pc_in_sigtramp, hppa32_hpux_frame_base_before_sigtramp and hppa32_hpux_frame_find_saved_regs_in_sigtramp: The signal context structure pointer is always saved at the base of the frame which "calls" the signal handler. We only want to find the hardware save state structure, which lives 10 32bit words into sigcontext structure. Within the hardware save state structure, registers are found in the same order as the register numbers in GDB. At one time we peeked at %r31 rather than the PC queues to determine what instruction took the fault. This was done on purpose, but I don't remember why. Looking at the PC queues is really the right way, and I don't remember why that didn't work when this code was originally written. */ void hppa32_hpux_frame_saved_pc_in_sigtramp (struct frame_info *fi, CORE_ADDR *tmp) { *tmp = read_memory_integer (get_frame_base (fi) + (43 * 4), 4); } void hppa32_hpux_frame_base_before_sigtramp (struct frame_info *fi, CORE_ADDR *tmp) { *tmp = read_memory_integer (get_frame_base (fi) + (40 * 4), 4); } void hppa32_hpux_frame_find_saved_regs_in_sigtramp (struct frame_info *fi, CORE_ADDR *fsr) { int i; const CORE_ADDR tmp = get_frame_base (fi) + (10 * 4); for (i = 0; i < NUM_REGS; i++) { if (i == HPPA_SP_REGNUM) fsr[HPPA_SP_REGNUM] = read_memory_integer (tmp + HPPA_SP_REGNUM * 4, 4); else fsr[i] = tmp + i * 4; } } /* For hppa64_hpux_frame_saved_pc_in_sigtramp, hppa64_hpux_frame_base_before_sigtramp and hppa64_hpux_frame_find_saved_regs_in_sigtramp: These functions are the PA64 ABI equivalents of the 32bits counterparts above. See the comments there. For PA64, the save_state structure is at an offset of 24 32-bit words from the sigcontext structure. The 64 bit general registers are at an offset of 640 bytes from the beginning of the save_state structure, and the floating pointer register are at an offset of 256 bytes from the beginning of the save_state structure. */ void hppa64_hpux_frame_saved_pc_in_sigtramp (struct frame_info *fi, CORE_ADDR *tmp) { *tmp = read_memory_integer (get_frame_base (fi) + (24 * 4) + 640 + (33 * 8), 8); } void hppa64_hpux_frame_base_before_sigtramp (struct frame_info *fi, CORE_ADDR *tmp) { *tmp = read_memory_integer (get_frame_base (fi) + (24 * 4) + 640 + (30 * 8), 8); } void hppa64_hpux_frame_find_saved_regs_in_sigtramp (struct frame_info *fi, CORE_ADDR *fsr) { int i; const CORE_ADDR tmp1 = get_frame_base (fi) + (24 * 4) + 640; const CORE_ADDR tmp2 = get_frame_base (fi) + (24 * 4) + 256; for (i = 0; i < NUM_REGS; i++) { if (i == HPPA_SP_REGNUM) fsr[HPPA_SP_REGNUM] = read_memory_integer (tmp1 + HPPA_SP_REGNUM * 8, 8); else if (i >= HPPA_FP0_REGNUM) fsr[i] = tmp2 + (i - HPPA_FP0_REGNUM) * 8; else fsr[i] = tmp1 + i * 8; } } /* Return one if PC is in the call path of a trampoline, else return zero. Note we return one for *any* call trampoline (long-call, arg-reloc), not just shared library trampolines (import, export). */ static int hppa32_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name) { struct minimal_symbol *minsym; struct unwind_table_entry *u; static CORE_ADDR dyncall = 0; static CORE_ADDR sr4export = 0; /* FIXME XXX - dyncall and sr4export must be initialized whenever we get a new exec file */ /* First see if PC is in one of the two C-library trampolines. */ if (!dyncall) { minsym = lookup_minimal_symbol ("$$dyncall", NULL, NULL); if (minsym) dyncall = SYMBOL_VALUE_ADDRESS (minsym); else dyncall = -1; } if (!sr4export) { minsym = lookup_minimal_symbol ("_sr4export", NULL, NULL); if (minsym) sr4export = SYMBOL_VALUE_ADDRESS (minsym); else sr4export = -1; } if (pc == dyncall || pc == sr4export) return 1; minsym = lookup_minimal_symbol_by_pc (pc); if (minsym && strcmp (DEPRECATED_SYMBOL_NAME (minsym), ".stub") == 0) return 1; /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub, then return now. */ if (u->stub_unwind.stub_type == 0) return 0; /* By definition a long-branch stub is a call stub. */ if (u->stub_unwind.stub_type == LONG_BRANCH) return 1; /* The call and return path execute the same instructions within an IMPORT stub! So an IMPORT stub is both a call and return trampoline. */ if (u->stub_unwind.stub_type == IMPORT) return 1; /* Parameter relocation stubs always have a call path and may have a return path. */ if (u->stub_unwind.stub_type == PARAMETER_RELOCATION || u->stub_unwind.stub_type == EXPORT) { CORE_ADDR addr; /* Search forward from the current PC until we hit a branch or the end of the stub. */ for (addr = pc; addr <= u->region_end; addr += 4) { unsigned long insn; insn = read_memory_integer (addr, 4); /* Does it look like a bl? If so then it's the call path, if we find a bv or be first, then we're on the return path. */ if ((insn & 0xfc00e000) == 0xe8000000) return 1; else if ((insn & 0xfc00e001) == 0xe800c000 || (insn & 0xfc000000) == 0xe0000000) return 0; } /* Should never happen. */ warning ("Unable to find branch in parameter relocation stub.\n"); return 0; } /* Unknown stub type. For now, just return zero. */ return 0; } static int hppa64_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name) { /* PA64 has a completely different stub/trampoline scheme. Is it better? Maybe. It's certainly harder to determine with any certainty that we are in a stub because we can not refer to the unwinders to help. The heuristic is simple. Try to lookup the current PC value in th minimal symbol table. If that fails, then assume we are not in a stub and return. Then see if the PC value falls within the section bounds for the section containing the minimal symbol we found in the first step. If it does, then assume we are not in a stub and return. Finally peek at the instructions to see if they look like a stub. */ struct minimal_symbol *minsym; asection *sec; CORE_ADDR addr; int insn, i; minsym = lookup_minimal_symbol_by_pc (pc); if (! minsym) return 0; sec = SYMBOL_BFD_SECTION (minsym); if (bfd_get_section_vma (sec->owner, sec) <= pc && pc < (bfd_get_section_vma (sec->owner, sec) + bfd_section_size (sec->owner, sec))) return 0; /* We might be in a stub. Peek at the instructions. Stubs are 3 instructions long. */ insn = read_memory_integer (pc, 4); /* Find out where we think we are within the stub. */ if ((insn & 0xffffc00e) == 0x53610000) addr = pc; else if ((insn & 0xffffffff) == 0xe820d000) addr = pc - 4; else if ((insn & 0xffffc00e) == 0x537b0000) addr = pc - 8; else return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr, 4); if ((insn & 0xffffc00e) != 0x53610000) return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr + 4, 4); if ((insn & 0xffffffff) != 0xe820d000) return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr + 8, 4); if ((insn & 0xffffc00e) != 0x537b0000) return 0; /* Looks like a stub. */ return 1; } /* Return one if PC is in the return path of a trampoline, else return zero. Note we return one for *any* call trampoline (long-call, arg-reloc), not just shared library trampolines (import, export). */ static int hppa_hpux_in_solib_return_trampoline (CORE_ADDR pc, char *name) { struct unwind_table_entry *u; /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub or it's just a long branch stub, then return zero. */ if (u->stub_unwind.stub_type == 0 || u->stub_unwind.stub_type == LONG_BRANCH) return 0; /* The call and return path execute the same instructions within an IMPORT stub! So an IMPORT stub is both a call and return trampoline. */ if (u->stub_unwind.stub_type == IMPORT) return 1; /* Parameter relocation stubs always have a call path and may have a return path. */ if (u->stub_unwind.stub_type == PARAMETER_RELOCATION || u->stub_unwind.stub_type == EXPORT) { CORE_ADDR addr; /* Search forward from the current PC until we hit a branch or the end of the stub. */ for (addr = pc; addr <= u->region_end; addr += 4) { unsigned long insn; insn = read_memory_integer (addr, 4); /* Does it look like a bl? If so then it's the call path, if we find a bv or be first, then we're on the return path. */ if ((insn & 0xfc00e000) == 0xe8000000) return 0; else if ((insn & 0xfc00e001) == 0xe800c000 || (insn & 0xfc000000) == 0xe0000000) return 1; } /* Should never happen. */ warning ("Unable to find branch in parameter relocation stub.\n"); return 0; } /* Unknown stub type. For now, just return zero. */ return 0; } /* Figure out if PC is in a trampoline, and if so find out where the trampoline will jump to. If not in a trampoline, return zero. Simple code examination probably is not a good idea since the code sequences in trampolines can also appear in user code. We use unwinds and information from the minimal symbol table to determine when we're in a trampoline. This won't work for ELF (yet) since it doesn't create stub unwind entries. Whether or not ELF will create stub unwinds or normal unwinds for linker stubs is still being debated. This should handle simple calls through dyncall or sr4export, long calls, argument relocation stubs, and dyncall/sr4export calling an argument relocation stub. It even handles some stubs used in dynamic executables. */ static CORE_ADDR hppa_hpux_skip_trampoline_code (CORE_ADDR pc) { long orig_pc = pc; long prev_inst, curr_inst, loc; static CORE_ADDR dyncall = 0; static CORE_ADDR dyncall_external = 0; static CORE_ADDR sr4export = 0; struct minimal_symbol *msym; struct unwind_table_entry *u; /* FIXME XXX - dyncall and sr4export must be initialized whenever we get a new exec file */ if (!dyncall) { msym = lookup_minimal_symbol ("$$dyncall", NULL, NULL); if (msym) dyncall = SYMBOL_VALUE_ADDRESS (msym); else dyncall = -1; } if (!dyncall_external) { msym = lookup_minimal_symbol ("$$dyncall_external", NULL, NULL); if (msym) dyncall_external = SYMBOL_VALUE_ADDRESS (msym); else dyncall_external = -1; } if (!sr4export) { msym = lookup_minimal_symbol ("_sr4export", NULL, NULL); if (msym) sr4export = SYMBOL_VALUE_ADDRESS (msym); else sr4export = -1; } /* Addresses passed to dyncall may *NOT* be the actual address of the function. So we may have to do something special. */ if (pc == dyncall) { pc = (CORE_ADDR) read_register (22); /* If bit 30 (counting from the left) is on, then pc is the address of the PLT entry for this function, not the address of the function itself. Bit 31 has meaning too, but only for MPE. */ if (pc & 0x2) pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8); } if (pc == dyncall_external) { pc = (CORE_ADDR) read_register (22); pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8); } else if (pc == sr4export) pc = (CORE_ADDR) (read_register (22)); /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub, then return now. */ /* elz: attention here! (FIXME) because of a compiler/linker error, some stubs which should have a non zero stub_unwind.stub_type have unfortunately a value of zero. So this function would return here as if we were not in a trampoline. To fix this, we go look at the partial symbol information, which reports this guy as a stub. (FIXME): Unfortunately, we are not that lucky: it turns out that the partial symbol information is also wrong sometimes. This is because when it is entered (somread.c::som_symtab_read()) it can happen that if the type of the symbol (from the som) is Entry, and the symbol is in a shared library, then it can also be a trampoline. This would be OK, except that I believe the way they decide if we are ina shared library does not work. SOOOO..., even if we have a regular function w/o trampolines its minimal symbol can be assigned type mst_solib_trampoline. Also, if we find that the symbol is a real stub, then we fix the unwind descriptor, and define the stub type to be EXPORT. Hopefully this is correct most of the times. */ if (u->stub_unwind.stub_type == 0) { /* elz: NOTE (FIXME!) once the problem with the unwind information is fixed we can delete all the code which appears between the lines */ /*--------------------------------------------------------------------------*/ msym = lookup_minimal_symbol_by_pc (pc); if (msym == NULL || MSYMBOL_TYPE (msym) != mst_solib_trampoline) return orig_pc == pc ? 0 : pc & ~0x3; else if (msym != NULL && MSYMBOL_TYPE (msym) == mst_solib_trampoline) { struct objfile *objfile; struct minimal_symbol *msymbol; int function_found = 0; /* go look if there is another minimal symbol with the same name as this one, but with type mst_text. This would happen if the msym is an actual trampoline, in which case there would be another symbol with the same name corresponding to the real function */ ALL_MSYMBOLS (objfile, msymbol) { if (MSYMBOL_TYPE (msymbol) == mst_text && DEPRECATED_STREQ (DEPRECATED_SYMBOL_NAME (msymbol), DEPRECATED_SYMBOL_NAME (msym))) { function_found = 1; break; } } if (function_found) /* the type of msym is correct (mst_solib_trampoline), but the unwind info is wrong, so set it to the correct value */ u->stub_unwind.stub_type = EXPORT; else /* the stub type info in the unwind is correct (this is not a trampoline), but the msym type information is wrong, it should be mst_text. So we need to fix the msym, and also get out of this function */ { MSYMBOL_TYPE (msym) = mst_text; return orig_pc == pc ? 0 : pc & ~0x3; } } /*--------------------------------------------------------------------------*/ } /* It's a stub. Search for a branch and figure out where it goes. Note we have to handle multi insn branch sequences like ldil;ble. Most (all?) other branches can be determined by examining the contents of certain registers and the stack. */ loc = pc; curr_inst = 0; prev_inst = 0; while (1) { /* Make sure we haven't walked outside the range of this stub. */ if (u != find_unwind_entry (loc)) { warning ("Unable to find branch in linker stub"); return orig_pc == pc ? 0 : pc & ~0x3; } prev_inst = curr_inst; curr_inst = read_memory_integer (loc, 4); /* Does it look like a branch external using %r1? Then it's the branch from the stub to the actual function. */ if ((curr_inst & 0xffe0e000) == 0xe0202000) { /* Yup. See if the previous instruction loaded a value into %r1. If so compute and return the jump address. */ if ((prev_inst & 0xffe00000) == 0x20200000) return (hppa_extract_21 (prev_inst) + hppa_extract_17 (curr_inst)) & ~0x3; else { warning ("Unable to find ldil X,%%r1 before ble Y(%%sr4,%%r1)."); return orig_pc == pc ? 0 : pc & ~0x3; } } /* Does it look like a be 0(sr0,%r21)? OR Does it look like a be, n 0(sr0,%r21)? OR Does it look like a bve (r21)? (this is on PA2.0) Does it look like a bve, n(r21)? (this is also on PA2.0) That's the branch from an import stub to an export stub. It is impossible to determine the target of the branch via simple examination of instructions and/or data (consider that the address in the plabel may be the address of the bind-on-reference routine in the dynamic loader). So we have try an alternative approach. Get the name of the symbol at our current location; it should be a stub symbol with the same name as the symbol in the shared library. Then lookup a minimal symbol with the same name; we should get the minimal symbol for the target routine in the shared library as those take precedence of import/export stubs. */ if ((curr_inst == 0xe2a00000) || (curr_inst == 0xe2a00002) || (curr_inst == 0xeaa0d000) || (curr_inst == 0xeaa0d002)) { struct minimal_symbol *stubsym, *libsym; stubsym = lookup_minimal_symbol_by_pc (loc); if (stubsym == NULL) { warning ("Unable to find symbol for 0x%lx", loc); return orig_pc == pc ? 0 : pc & ~0x3; } libsym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (stubsym), NULL, NULL); if (libsym == NULL) { warning ("Unable to find library symbol for %s\n", DEPRECATED_SYMBOL_NAME (stubsym)); return orig_pc == pc ? 0 : pc & ~0x3; } return SYMBOL_VALUE (libsym); } /* Does it look like bl X,%rp or bl X,%r0? Another way to do a branch from the stub to the actual function. */ /*elz */ else if ((curr_inst & 0xffe0e000) == 0xe8400000 || (curr_inst & 0xffe0e000) == 0xe8000000 || (curr_inst & 0xffe0e000) == 0xe800A000) return (loc + hppa_extract_17 (curr_inst) + 8) & ~0x3; /* Does it look like bv (rp)? Note this depends on the current stack pointer being the same as the stack pointer in the stub itself! This is a branch on from the stub back to the original caller. */ /*else if ((curr_inst & 0xffe0e000) == 0xe840c000) */ else if ((curr_inst & 0xffe0f000) == 0xe840c000) { /* Yup. See if the previous instruction loaded rp from sp - 8. */ if (prev_inst == 0x4bc23ff1) return (read_memory_integer (read_register (HPPA_SP_REGNUM) - 8, 4)) & ~0x3; else { warning ("Unable to find restore of %%rp before bv (%%rp)."); return orig_pc == pc ? 0 : pc & ~0x3; } } /* elz: added this case to capture the new instruction at the end of the return part of an export stub used by the PA2.0: BVE, n (rp) */ else if ((curr_inst & 0xffe0f000) == 0xe840d000) { return (read_memory_integer (read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3; } /* What about be,n 0(sr0,%rp)? It's just another way we return to the original caller from the stub. Used in dynamic executables. */ else if (curr_inst == 0xe0400002) { /* The value we jump to is sitting in sp - 24. But that's loaded several instructions before the be instruction. I guess we could check for the previous instruction being mtsp %r1,%sr0 if we want to do sanity checking. */ return (read_memory_integer (read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3; } /* Haven't found the branch yet, but we're still in the stub. Keep looking. */ loc += 4; } } /* Exception handling support for the HP-UX ANSI C++ compiler. The compiler (aCC) provides a callback for exception events; GDB can set a breakpoint on this callback and find out what exception event has occurred. */ /* The name of the hook to be set to point to the callback function */ static char HP_ACC_EH_notify_hook[] = "__eh_notify_hook"; /* The name of the function to be used to set the hook value */ static char HP_ACC_EH_set_hook_value[] = "__eh_set_hook_value"; /* The name of the callback function in end.o */ static char HP_ACC_EH_notify_callback[] = "__d_eh_notify_callback"; /* Name of function in end.o on which a break is set (called by above) */ static char HP_ACC_EH_break[] = "__d_eh_break"; /* Name of flag (in end.o) that enables catching throws */ static char HP_ACC_EH_catch_throw[] = "__d_eh_catch_throw"; /* Name of flag (in end.o) that enables catching catching */ static char HP_ACC_EH_catch_catch[] = "__d_eh_catch_catch"; /* The enum used by aCC */ typedef enum { __EH_NOTIFY_THROW, __EH_NOTIFY_CATCH } __eh_notification; /* Is exception-handling support available with this executable? */ static int hp_cxx_exception_support = 0; /* Has the initialize function been run? */ int hp_cxx_exception_support_initialized = 0; /* Address of __eh_notify_hook */ static CORE_ADDR eh_notify_hook_addr = 0; /* Address of __d_eh_notify_callback */ static CORE_ADDR eh_notify_callback_addr = 0; /* Address of __d_eh_break */ static CORE_ADDR eh_break_addr = 0; /* Address of __d_eh_catch_catch */ static CORE_ADDR eh_catch_catch_addr = 0; /* Address of __d_eh_catch_throw */ static CORE_ADDR eh_catch_throw_addr = 0; /* Sal for __d_eh_break */ static struct symtab_and_line *break_callback_sal = 0; /* Code in end.c expects __d_pid to be set in the inferior, otherwise __d_eh_notify_callback doesn't bother to call __d_eh_break! So we poke the pid into this symbol ourselves. 0 => success 1 => failure */ int setup_d_pid_in_inferior (void) { CORE_ADDR anaddr; struct minimal_symbol *msymbol; char buf[4]; /* FIXME 32x64? */ /* Slam the pid of the process into __d_pid; failing is only a warning! */ msymbol = lookup_minimal_symbol ("__d_pid", NULL, symfile_objfile); if (msymbol == NULL) { warning ("Unable to find __d_pid symbol in object file."); warning ("Suggest linking executable with -g (links in /opt/langtools/lib/end.o)."); return 1; } anaddr = SYMBOL_VALUE_ADDRESS (msymbol); store_unsigned_integer (buf, 4, PIDGET (inferior_ptid)); /* FIXME 32x64? */ if (target_write_memory (anaddr, buf, 4)) /* FIXME 32x64? */ { warning ("Unable to write __d_pid"); warning ("Suggest linking executable with -g (links in /opt/langtools/lib/end.o)."); return 1; } return 0; } /* elz: Used to lookup a symbol in the shared libraries. This function calls shl_findsym, indirectly through a call to __d_shl_get. __d_shl_get is in end.c, which is always linked in by the hp compilers/linkers. The call to shl_findsym cannot be made directly because it needs to be active in target address space. inputs: - minimal symbol pointer for the function we want to look up - address in target space of the descriptor for the library where we want to look the symbol up. This address is retrieved using the som_solib_get_solib_by_pc function (somsolib.c). output: - real address in the library of the function. note: the handle can be null, in which case shl_findsym will look for the symbol in all the loaded shared libraries. files to look at if you need reference on this stuff: dld.c, dld_shl_findsym.c end.c man entry for shl_findsym */ CORE_ADDR find_stub_with_shl_get (struct minimal_symbol *function, CORE_ADDR handle) { struct symbol *get_sym, *symbol2; struct minimal_symbol *buff_minsym, *msymbol; struct type *ftype; struct value **args; struct value *funcval; struct value *val; int x, namelen, err_value, tmp = -1; CORE_ADDR endo_buff_addr, value_return_addr, errno_return_addr; CORE_ADDR stub_addr; args = alloca (sizeof (struct value *) * 8); /* 6 for the arguments and one null one??? */ funcval = find_function_in_inferior ("__d_shl_get"); get_sym = lookup_symbol ("__d_shl_get", NULL, VAR_DOMAIN, NULL, NULL); buff_minsym = lookup_minimal_symbol ("__buffer", NULL, NULL); msymbol = lookup_minimal_symbol ("__shldp", NULL, NULL); symbol2 = lookup_symbol ("__shldp", NULL, VAR_DOMAIN, NULL, NULL); endo_buff_addr = SYMBOL_VALUE_ADDRESS (buff_minsym); namelen = strlen (DEPRECATED_SYMBOL_NAME (function)); value_return_addr = endo_buff_addr + namelen; ftype = check_typedef (SYMBOL_TYPE (get_sym)); /* do alignment */ if ((x = value_return_addr % 64) != 0) value_return_addr = value_return_addr + 64 - x; errno_return_addr = value_return_addr + 64; /* set up stuff needed by __d_shl_get in buffer in end.o */ target_write_memory (endo_buff_addr, DEPRECATED_SYMBOL_NAME (function), namelen); target_write_memory (value_return_addr, (char *) &tmp, 4); target_write_memory (errno_return_addr, (char *) &tmp, 4); target_write_memory (SYMBOL_VALUE_ADDRESS (msymbol), (char *) &handle, 4); /* now prepare the arguments for the call */ args[0] = value_from_longest (TYPE_FIELD_TYPE (ftype, 0), 12); args[1] = value_from_pointer (TYPE_FIELD_TYPE (ftype, 1), SYMBOL_VALUE_ADDRESS (msymbol)); args[2] = value_from_pointer (TYPE_FIELD_TYPE (ftype, 2), endo_buff_addr); args[3] = value_from_longest (TYPE_FIELD_TYPE (ftype, 3), TYPE_PROCEDURE); args[4] = value_from_pointer (TYPE_FIELD_TYPE (ftype, 4), value_return_addr); args[5] = value_from_pointer (TYPE_FIELD_TYPE (ftype, 5), errno_return_addr); /* now call the function */ val = call_function_by_hand (funcval, 6, args); /* now get the results */ target_read_memory (errno_return_addr, (char *) &err_value, sizeof (err_value)); target_read_memory (value_return_addr, (char *) &stub_addr, sizeof (stub_addr)); if (stub_addr <= 0) error ("call to __d_shl_get failed, error code is %d", err_value); return (stub_addr); } /* Cover routine for find_stub_with_shl_get to pass to catch_errors */ static int cover_find_stub_with_shl_get (void *args_untyped) { args_for_find_stub *args = args_untyped; args->return_val = find_stub_with_shl_get (args->msym, args->solib_handle); return 0; } /* Initialize exception catchpoint support by looking for the necessary hooks/callbacks in end.o, etc., and set the hook value to point to the required debug function Return 0 => failure 1 => success */ static int initialize_hp_cxx_exception_support (void) { struct symtabs_and_lines sals; struct cleanup *old_chain; struct cleanup *canonical_strings_chain = NULL; int i; char *addr_start; char *addr_end = NULL; char **canonical = (char **) NULL; int thread = -1; struct symbol *sym = NULL; struct minimal_symbol *msym = NULL; struct objfile *objfile; asection *shlib_info; /* Detect and disallow recursion. On HP-UX with aCC, infinite recursion is a possibility because finding the hook for exception callbacks involves making a call in the inferior, which means re-inserting breakpoints which can re-invoke this code */ static int recurse = 0; if (recurse > 0) { hp_cxx_exception_support_initialized = 0; deprecated_exception_support_initialized = 0; return 0; } hp_cxx_exception_support = 0; /* First check if we have seen any HP compiled objects; if not, it is very unlikely that HP's idiosyncratic callback mechanism for exception handling debug support will be available! This will percolate back up to breakpoint.c, where our callers will decide to try the g++ exception-handling support instead. */ if (!deprecated_hp_som_som_object_present) return 0; /* We have a SOM executable with SOM debug info; find the hooks */ /* First look for the notify hook provided by aCC runtime libs */ /* If we find this symbol, we conclude that the executable must have HP aCC exception support built in. If this symbol is not found, even though we're a HP SOM-SOM file, we may have been built with some other compiler (not aCC). This results percolates back up to our callers in breakpoint.c which can decide to try the g++ style of exception support instead. If this symbol is found but the other symbols we require are not found, there is something weird going on, and g++ support should *not* be tried as an alternative. ASSUMPTION: Only HP aCC code will have __eh_notify_hook defined. ASSUMPTION: HP aCC and g++ modules cannot be linked together. */ /* libCsup has this hook; it'll usually be non-debuggable */ msym = lookup_minimal_symbol (HP_ACC_EH_notify_hook, NULL, NULL); if (msym) { eh_notify_hook_addr = SYMBOL_VALUE_ADDRESS (msym); hp_cxx_exception_support = 1; } else { warning ("Unable to find exception callback hook (%s).", HP_ACC_EH_notify_hook); warning ("Executable may not have been compiled debuggable with HP aCC."); warning ("GDB will be unable to intercept exception events."); eh_notify_hook_addr = 0; hp_cxx_exception_support = 0; return 0; } /* Next look for the notify callback routine in end.o */ /* This is always available in the SOM symbol dictionary if end.o is linked in */ msym = lookup_minimal_symbol (HP_ACC_EH_notify_callback, NULL, NULL); if (msym) { eh_notify_callback_addr = SYMBOL_VALUE_ADDRESS (msym); hp_cxx_exception_support = 1; } else { warning ("Unable to find exception callback routine (%s).", HP_ACC_EH_notify_callback); warning ("Suggest linking executable with -g (links in /opt/langtools/lib/end.o)."); warning ("GDB will be unable to intercept exception events."); eh_notify_callback_addr = 0; return 0; } #ifndef GDB_TARGET_IS_HPPA_20W /* Check whether the executable is dynamically linked or archive bound */ /* With an archive-bound executable we can use the raw addresses we find for the callback function, etc. without modification. For an executable with shared libraries, we have to do more work to find the plabel, which can be the target of a call through $$dyncall from the aCC runtime support library (libCsup) which is linked shared by default by aCC. */ /* This test below was copied from somsolib.c/somread.c. It may not be a very reliable one to test that an executable is linked shared. pai/1997-07-18 */ shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$"); if (shlib_info && (bfd_section_size (symfile_objfile->obfd, shlib_info) != 0)) { /* The minsym we have has the local code address, but that's not the plabel that can be used by an inter-load-module call. */ /* Find solib handle for main image (which has end.o), and use that and the min sym as arguments to __d_shl_get() (which does the equivalent of shl_findsym()) to find the plabel. */ args_for_find_stub args; static char message[] = "Error while finding exception callback hook:\n"; args.solib_handle = som_solib_get_solib_by_pc (eh_notify_callback_addr); args.msym = msym; args.return_val = 0; recurse++; catch_errors (cover_find_stub_with_shl_get, &args, message, RETURN_MASK_ALL); eh_notify_callback_addr = args.return_val; recurse--; deprecated_exception_catchpoints_are_fragile = 1; if (!eh_notify_callback_addr) { /* We can get here either if there is no plabel in the export list for the main image, or if something strange happened (?) */ warning ("Couldn't find a plabel (indirect function label) for the exception callback."); warning ("GDB will not be able to intercept exception events."); return 0; } } else deprecated_exception_catchpoints_are_fragile = 0; #endif /* Now, look for the breakpointable routine in end.o */ /* This should also be available in the SOM symbol dict. if end.o linked in */ msym = lookup_minimal_symbol (HP_ACC_EH_break, NULL, NULL); if (msym) { eh_break_addr = SYMBOL_VALUE_ADDRESS (msym); hp_cxx_exception_support = 1; } else { warning ("Unable to find exception callback routine to set breakpoint (%s).", HP_ACC_EH_break); warning ("Suggest linking executable with -g (link in /opt/langtools/lib/end.o)."); warning ("GDB will be unable to intercept exception events."); eh_break_addr = 0; return 0; } /* Next look for the catch enable flag provided in end.o */ sym = lookup_symbol (HP_ACC_EH_catch_catch, (struct block *) NULL, VAR_DOMAIN, 0, (struct symtab **) NULL); if (sym) /* sometimes present in debug info */ { eh_catch_catch_addr = SYMBOL_VALUE_ADDRESS (sym); hp_cxx_exception_support = 1; } else /* otherwise look in SOM symbol dict. */ { msym = lookup_minimal_symbol (HP_ACC_EH_catch_catch, NULL, NULL); if (msym) { eh_catch_catch_addr = SYMBOL_VALUE_ADDRESS (msym); hp_cxx_exception_support = 1; } else { warning ("Unable to enable interception of exception catches."); warning ("Executable may not have been compiled debuggable with HP aCC."); warning ("Suggest linking executable with -g (link in /opt/langtools/lib/end.o)."); return 0; } } /* Next look for the catch enable flag provided end.o */ sym = lookup_symbol (HP_ACC_EH_catch_catch, (struct block *) NULL, VAR_DOMAIN, 0, (struct symtab **) NULL); if (sym) /* sometimes present in debug info */ { eh_catch_throw_addr = SYMBOL_VALUE_ADDRESS (sym); hp_cxx_exception_support = 1; } else /* otherwise look in SOM symbol dict. */ { msym = lookup_minimal_symbol (HP_ACC_EH_catch_throw, NULL, NULL); if (msym) { eh_catch_throw_addr = SYMBOL_VALUE_ADDRESS (msym); hp_cxx_exception_support = 1; } else { warning ("Unable to enable interception of exception throws."); warning ("Executable may not have been compiled debuggable with HP aCC."); warning ("Suggest linking executable with -g (link in /opt/langtools/lib/end.o)."); return 0; } } /* Set the flags */ hp_cxx_exception_support = 2; /* everything worked so far */ hp_cxx_exception_support_initialized = 1; deprecated_exception_support_initialized = 1; return 1; } /* Target operation for enabling or disabling interception of exception events. KIND is either EX_EVENT_THROW or EX_EVENT_CATCH ENABLE is either 0 (disable) or 1 (enable). Return value is NULL if no support found; -1 if something went wrong, or a pointer to a symtab/line struct if the breakpointable address was found. */ struct symtab_and_line * child_enable_exception_callback (enum exception_event_kind kind, int enable) { char buf[4]; if (!deprecated_exception_support_initialized || !hp_cxx_exception_support_initialized) if (!initialize_hp_cxx_exception_support ()) return NULL; switch (hp_cxx_exception_support) { case 0: /* Assuming no HP support at all */ return NULL; case 1: /* HP support should be present, but something went wrong */ return (struct symtab_and_line *) -1; /* yuck! */ /* there may be other cases in the future */ } /* Set the EH hook to point to the callback routine */ store_unsigned_integer (buf, 4, enable ? eh_notify_callback_addr : 0); /* FIXME 32x64 problem */ /* pai: (temp) FIXME should there be a pack operation first? */ if (target_write_memory (eh_notify_hook_addr, buf, 4)) /* FIXME 32x64 problem */ { warning ("Could not write to target memory for exception event callback."); warning ("Interception of exception events may not work."); return (struct symtab_and_line *) -1; } if (enable) { /* Ensure that __d_pid is set up correctly -- end.c code checks this. :-( */ if (PIDGET (inferior_ptid) > 0) { if (setup_d_pid_in_inferior ()) return (struct symtab_and_line *) -1; } else { warning ("Internal error: Invalid inferior pid? Cannot intercept exception events."); return (struct symtab_and_line *) -1; } } switch (kind) { case EX_EVENT_THROW: store_unsigned_integer (buf, 4, enable ? 1 : 0); if (target_write_memory (eh_catch_throw_addr, buf, 4)) /* FIXME 32x64? */ { warning ("Couldn't enable exception throw interception."); return (struct symtab_and_line *) -1; } break; case EX_EVENT_CATCH: store_unsigned_integer (buf, 4, enable ? 1 : 0); if (target_write_memory (eh_catch_catch_addr, buf, 4)) /* FIXME 32x64? */ { warning ("Couldn't enable exception catch interception."); return (struct symtab_and_line *) -1; } break; default: error ("Request to enable unknown or unsupported exception event."); } /* Copy break address into new sal struct, malloc'ing if needed. */ if (!break_callback_sal) { break_callback_sal = (struct symtab_and_line *) xmalloc (sizeof (struct symtab_and_line)); } init_sal (break_callback_sal); break_callback_sal->symtab = NULL; break_callback_sal->pc = eh_break_addr; break_callback_sal->line = 0; break_callback_sal->end = eh_break_addr; return break_callback_sal; } /* Record some information about the current exception event */ static struct exception_event_record current_ex_event; /* Convenience struct */ static struct symtab_and_line null_symtab_and_line = {NULL, 0, 0, 0}; /* Report current exception event. Returns a pointer to a record that describes the kind of the event, where it was thrown from, and where it will be caught. More information may be reported in the future */ struct exception_event_record * child_get_current_exception_event (void) { CORE_ADDR event_kind; CORE_ADDR throw_addr; CORE_ADDR catch_addr; struct frame_info *fi, *curr_frame; int level = 1; curr_frame = get_current_frame (); if (!curr_frame) return (struct exception_event_record *) NULL; /* Go up one frame to __d_eh_notify_callback, because at the point when this code is executed, there's garbage in the arguments of __d_eh_break. */ fi = find_relative_frame (curr_frame, &level); if (level != 0) return (struct exception_event_record *) NULL; select_frame (fi); /* Read in the arguments */ /* __d_eh_notify_callback() is called with 3 arguments: 1. event kind catch or throw 2. the target address if known 3. a flag -- not sure what this is. pai/1997-07-17 */ event_kind = read_register (HPPA_ARG0_REGNUM); catch_addr = read_register (HPPA_ARG1_REGNUM); /* Now go down to a user frame */ /* For a throw, __d_eh_break is called by __d_eh_notify_callback which is called by __notify_throw which is called from user code. For a catch, __d_eh_break is called by __d_eh_notify_callback which is called by which is called by __throw__ or __rethrow_ which is called from user code. */ /* FIXME: Don't use such magic numbers; search for the frames */ level = (event_kind == EX_EVENT_THROW) ? 3 : 4; fi = find_relative_frame (curr_frame, &level); if (level != 0) return (struct exception_event_record *) NULL; select_frame (fi); throw_addr = get_frame_pc (fi); /* Go back to original (top) frame */ select_frame (curr_frame); current_ex_event.kind = (enum exception_event_kind) event_kind; current_ex_event.throw_sal = find_pc_line (throw_addr, 1); current_ex_event.catch_sal = find_pc_line (catch_addr, 1); return ¤t_ex_event; } static void hppa_hpux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (tdep->bytes_per_address == 4) set_gdbarch_in_solib_call_trampoline (gdbarch, hppa32_hpux_in_solib_call_trampoline); else set_gdbarch_in_solib_call_trampoline (gdbarch, hppa64_hpux_in_solib_call_trampoline); set_gdbarch_in_solib_return_trampoline (gdbarch, hppa_hpux_in_solib_return_trampoline); set_gdbarch_skip_trampoline_code (gdbarch, hppa_hpux_skip_trampoline_code); } static void hppa_hpux_som_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); tdep->is_elf = 0; hppa_hpux_init_abi (info, gdbarch); } static void hppa_hpux_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); tdep->is_elf = 1; hppa_hpux_init_abi (info, gdbarch); } void _initialize_hppa_hpux_tdep (void) { gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_HPUX_SOM, hppa_hpux_som_init_abi); gdbarch_register_osabi (bfd_arch_hppa, bfd_mach_hppa20w, GDB_OSABI_HPUX_ELF, hppa_hpux_elf_init_abi); }