| /* 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 "frame-unwind.h" |
| #include "trad-frame.h" |
| #include "symtab.h" |
| #include "objfiles.h" |
| #include "inferior.h" |
| #include "infcall.h" |
| #include "observer.h" |
| #include "hppa-tdep.h" |
| |
| #include <dl.h> |
| #include <machine/save_state.h> |
| |
| #ifndef offsetof |
| #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| #endif |
| |
| /* 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; |
| |
| /* 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; |
| |
| /* First see if PC is in one of the two C-library trampolines. */ |
| if (pc == hppa_symbol_address("$$dyncall") |
| || pc == hppa_symbol_address("_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; |
| struct minimal_symbol *msym; |
| struct unwind_table_entry *u; |
| |
| /* Addresses passed to dyncall may *NOT* be the actual address |
| of the function. So we may have to do something special. */ |
| if (pc == hppa_symbol_address("$$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 == hppa_symbol_address("$$dyncall_external")) |
| { |
| pc = (CORE_ADDR) read_register (22); |
| pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8); |
| } |
| else if (pc == hppa_symbol_address("_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? */ |
| static 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 |
| <stackwalking stuff> which is called by |
| __throw__<stuff> or __rethrow_<stuff> 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; |
| } |
| |
| /* Signal frames. */ |
| struct hppa_hpux_sigtramp_unwind_cache |
| { |
| CORE_ADDR base; |
| struct trad_frame_saved_reg *saved_regs; |
| }; |
| |
| static int hppa_hpux_tramp_reg[] = { |
| HPPA_SAR_REGNUM, |
| HPPA_PCOQ_HEAD_REGNUM, |
| HPPA_PCSQ_HEAD_REGNUM, |
| HPPA_PCOQ_TAIL_REGNUM, |
| HPPA_PCSQ_TAIL_REGNUM, |
| HPPA_EIEM_REGNUM, |
| HPPA_IIR_REGNUM, |
| HPPA_ISR_REGNUM, |
| HPPA_IOR_REGNUM, |
| HPPA_IPSW_REGNUM, |
| -1, |
| HPPA_SR4_REGNUM, |
| HPPA_SR4_REGNUM + 1, |
| HPPA_SR4_REGNUM + 2, |
| HPPA_SR4_REGNUM + 3, |
| HPPA_SR4_REGNUM + 4, |
| HPPA_SR4_REGNUM + 5, |
| HPPA_SR4_REGNUM + 6, |
| HPPA_SR4_REGNUM + 7, |
| HPPA_RCR_REGNUM, |
| HPPA_PID0_REGNUM, |
| HPPA_PID1_REGNUM, |
| HPPA_CCR_REGNUM, |
| HPPA_PID2_REGNUM, |
| HPPA_PID3_REGNUM, |
| HPPA_TR0_REGNUM, |
| HPPA_TR0_REGNUM + 1, |
| HPPA_TR0_REGNUM + 2, |
| HPPA_CR27_REGNUM |
| }; |
| |
| static struct hppa_hpux_sigtramp_unwind_cache * |
| hppa_hpux_sigtramp_frame_unwind_cache (struct frame_info *next_frame, |
| void **this_cache) |
| |
| { |
| struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| struct hppa_hpux_sigtramp_unwind_cache *info; |
| unsigned int flag; |
| CORE_ADDR sp, scptr; |
| int i, incr, off, szoff; |
| |
| if (*this_cache) |
| return *this_cache; |
| |
| info = FRAME_OBSTACK_ZALLOC (struct hppa_hpux_sigtramp_unwind_cache); |
| *this_cache = info; |
| info->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| |
| sp = frame_unwind_register_unsigned (next_frame, HPPA_SP_REGNUM); |
| |
| scptr = sp - 1352; |
| off = scptr; |
| |
| /* See /usr/include/machine/save_state.h for the structure of the save_state_t |
| structure. */ |
| |
| flag = read_memory_unsigned_integer(scptr, 4); |
| |
| if (!(flag & 0x40)) |
| { |
| /* Narrow registers. */ |
| off = scptr + offsetof (save_state_t, ss_narrow); |
| incr = 4; |
| szoff = 0; |
| } |
| else |
| { |
| /* Wide registers. */ |
| off = scptr + offsetof (save_state_t, ss_wide) + 8; |
| incr = 8; |
| szoff = (tdep->bytes_per_address == 4 ? 4 : 0); |
| } |
| |
| for (i = 1; i < 32; i++) |
| { |
| info->saved_regs[HPPA_R0_REGNUM + i].addr = off + szoff; |
| off += incr; |
| } |
| |
| for (i = 0; |
| i < sizeof(hppa_hpux_tramp_reg) / sizeof(hppa_hpux_tramp_reg[0]); |
| i++) |
| { |
| if (hppa_hpux_tramp_reg[i] > 0) |
| info->saved_regs[hppa_hpux_tramp_reg[i]].addr = off + szoff; |
| off += incr; |
| } |
| |
| /* TODO: fp regs */ |
| |
| info->base = frame_unwind_register_unsigned (next_frame, HPPA_SP_REGNUM); |
| |
| return info; |
| } |
| |
| static void |
| hppa_hpux_sigtramp_frame_this_id (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| struct frame_id *this_id) |
| { |
| struct hppa_hpux_sigtramp_unwind_cache *info |
| = hppa_hpux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| *this_id = frame_id_build (info->base, frame_pc_unwind (next_frame)); |
| } |
| |
| static void |
| hppa_hpux_sigtramp_frame_prev_register (struct frame_info *next_frame, |
| void **this_prologue_cache, |
| int regnum, int *optimizedp, |
| enum lval_type *lvalp, |
| CORE_ADDR *addrp, |
| int *realnump, void *valuep) |
| { |
| struct hppa_hpux_sigtramp_unwind_cache *info |
| = hppa_hpux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| hppa_frame_prev_register_helper (next_frame, info->saved_regs, regnum, |
| optimizedp, lvalp, addrp, realnump, valuep); |
| } |
| |
| static const struct frame_unwind hppa_hpux_sigtramp_frame_unwind = { |
| SIGTRAMP_FRAME, |
| hppa_hpux_sigtramp_frame_this_id, |
| hppa_hpux_sigtramp_frame_prev_register |
| }; |
| |
| static const struct frame_unwind * |
| hppa_hpux_sigtramp_unwind_sniffer (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| char *name; |
| |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| |
| if (name && strcmp(name, "_sigreturn") == 0) |
| return &hppa_hpux_sigtramp_frame_unwind; |
| |
| return NULL; |
| } |
| |
| static CORE_ADDR |
| hppa_hpux_som_find_global_pointer (struct value *function) |
| { |
| CORE_ADDR faddr; |
| |
| faddr = value_as_address (function); |
| |
| /* Is this a plabel? If so, dereference it to get the gp value. */ |
| if (faddr & 2) |
| { |
| int status; |
| char buf[4]; |
| |
| faddr &= ~3; |
| |
| status = target_read_memory (faddr + 4, buf, sizeof (buf)); |
| if (status == 0) |
| return extract_unsigned_integer (buf, sizeof (buf)); |
| } |
| |
| return som_solib_get_got_by_pc (faddr); |
| } |
| |
| static CORE_ADDR |
| hppa_hpux_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, |
| CORE_ADDR funcaddr, int using_gcc, |
| struct value **args, int nargs, |
| struct type *value_type, |
| CORE_ADDR *real_pc, CORE_ADDR *bp_addr) |
| { |
| /* FIXME: tausq/2004-06-09: This needs much more testing. It is broken |
| for pa64, but we should be able to get it to work with a little bit |
| of work. gdb-6.1 has a lot of code to handle various cases; I've tried to |
| simplify it and avoid compile-time conditionals. */ |
| |
| /* On HPUX, functions in the main executable and in libraries can be located |
| in different spaces. In order for us to be able to select the right |
| space for the function call, we need to go through an instruction seqeunce |
| to select the right space for the target function, call it, and then |
| restore the space on return. |
| |
| There are two helper routines that can be used for this task -- if |
| an application is linked with gcc, it will contain a __gcc_plt_call |
| helper function. __gcc_plt_call, when passed the entry point of an |
| import stub, will do the necessary space setting/restoration for the |
| target function. |
| |
| For programs that are compiled/linked with the HP compiler, a similar |
| function called __d_plt_call exists; __d_plt_call expects a PLABEL instead |
| of an import stub as an argument. |
| |
| // *INDENT-OFF* |
| To summarize, the call flow is: |
| current function -> dummy frame -> __gcc_plt_call (import stub) |
| -> target function |
| or |
| current function -> dummy frame -> __d_plt_call (plabel) |
| -> target function |
| // *INDENT-ON* |
| |
| In general the "funcaddr" argument passed to push_dummy_code is the actual |
| entry point of the target function. For __gcc_plt_call, we need to |
| locate the import stub for the corresponding function. Failing that, |
| we construct a dummy "import stub" on the stack to pass as an argument. |
| For __d_plt_call, we similarly synthesize a PLABEL on the stack to |
| pass to the helper function. |
| |
| An additional twist is that, in order for us to restore the space register |
| to its starting state, we need __gcc_plt_call/__d_plt_call to return |
| to the instruction where we started the call. However, if we put |
| the breakpoint there, gdb will complain because it will find two |
| frames on the stack with the same (sp, pc) (with the dummy frame in |
| between). Currently, we set the return pointer to (pc - 4) of the |
| current function. FIXME: This is not an ideal solution; possibly if the |
| current pc is at the beginning of a page, this will cause a page fault. |
| Need to understand this better and figure out a better way to fix it. */ |
| |
| struct minimal_symbol *sym; |
| |
| /* Nonzero if we will use GCC's PLT call routine. This routine must be |
| passed an import stub, not a PLABEL. It is also necessary to get %r19 |
| before performing the call. (This is done by push_dummy_call.) */ |
| int use_gcc_plt_call = 1; |
| |
| /* See if __gcc_plt_call is available; if not we will use the HP version |
| instead. */ |
| sym = lookup_minimal_symbol ("__gcc_plt_call", NULL, NULL); |
| if (sym == NULL) |
| use_gcc_plt_call = 0; |
| |
| /* If using __gcc_plt_call, we need to make sure we pass in an import |
| stub. funcaddr can be pointing to an export stub or a real function, |
| so we try to resolve it to the import stub. */ |
| if (use_gcc_plt_call) |
| { |
| struct objfile *objfile; |
| struct minimal_symbol *funsym, *stubsym; |
| CORE_ADDR stubaddr = 0; |
| |
| funsym = lookup_minimal_symbol_by_pc (funcaddr); |
| if (!funsym) |
| error ("Unable to find symbol for target function.\n"); |
| |
| ALL_OBJFILES (objfile) |
| { |
| stubsym = lookup_minimal_symbol_solib_trampoline |
| (SYMBOL_LINKAGE_NAME (funsym), objfile); |
| |
| if (stubsym) |
| { |
| struct unwind_table_entry *u; |
| |
| u = find_unwind_entry (SYMBOL_VALUE (stubsym)); |
| if (u == NULL |
| || (u->stub_unwind.stub_type != IMPORT |
| && u->stub_unwind.stub_type != IMPORT_SHLIB)) |
| continue; |
| |
| stubaddr = SYMBOL_VALUE (stubsym); |
| |
| /* If we found an IMPORT stub, then we can stop searching; |
| if we found an IMPORT_SHLIB, we want to continue the search |
| in the hopes that we will find an IMPORT stub. */ |
| if (u->stub_unwind.stub_type == IMPORT) |
| break; |
| } |
| } |
| |
| if (stubaddr != 0) |
| { |
| /* Argument to __gcc_plt_call is passed in r22. */ |
| regcache_cooked_write_unsigned (current_regcache, 22, stubaddr); |
| } |
| else |
| { |
| /* No import stub found; let's synthesize one. */ |
| |
| /* ldsid %r21, %r1 */ |
| write_memory_unsigned_integer (sp, 4, 0x02a010a1); |
| /* mtsp %r1,%sr0 */ |
| write_memory_unsigned_integer (sp + 4, 4, 0x00011820); |
| /* be 0(%sr0, %r21) */ |
| write_memory_unsigned_integer (sp + 8, 4, 0xe2a00000); |
| /* nop */ |
| write_memory_unsigned_integer (sp + 12, 4, 0x08000240); |
| |
| regcache_cooked_write_unsigned (current_regcache, 21, funcaddr); |
| regcache_cooked_write_unsigned (current_regcache, 22, sp); |
| } |
| |
| /* We set the breakpoint address and r31 to (close to) where the current |
| pc is; when __gcc_plt_call returns, it will restore pcsqh to the |
| current value based on this. The -4 is needed for frame unwinding |
| to work properly -- we need to land in a different function than |
| the current function. */ |
| *bp_addr = (read_register (HPPA_PCOQ_HEAD_REGNUM) & ~3) - 4; |
| regcache_cooked_write_unsigned (current_regcache, 31, *bp_addr); |
| |
| /* Continue from __gcc_plt_call. */ |
| *real_pc = SYMBOL_VALUE (sym); |
| } |
| else |
| { |
| unsigned int gp; |
| |
| /* Use __d_plt_call as a fallback; __d_plt_call expects to be called |
| with a plabel, so we need to build one. */ |
| |
| sym = lookup_minimal_symbol ("__d_plt_call", NULL, NULL); |
| if (sym == NULL) |
| error("Can't find an address for __d_plt_call or __gcc_plt_call " |
| "trampoline\nSuggest linking executable with -g or compiling " |
| "with gcc."); |
| |
| gp = gdbarch_tdep (gdbarch)->find_global_pointer (funcaddr); |
| write_memory_unsigned_integer (sp, 4, funcaddr); |
| write_memory_unsigned_integer (sp + 4, 4, gp); |
| |
| /* plabel is passed in r22 */ |
| regcache_cooked_write_unsigned (current_regcache, 22, sp); |
| } |
| |
| /* Pushed one stack frame, which has to be 64-byte aligned. */ |
| sp += 64; |
| |
| return sp; |
| } |
| |
| static void |
| hppa_hpux_inferior_created (struct target_ops *objfile, int from_tty) |
| { |
| /* Some HP-UX related globals to clear when a new "main" |
| symbol file is loaded. HP-specific. */ |
| deprecated_hp_som_som_object_present = 0; |
| hp_cxx_exception_support_initialized = 0; |
| } |
| |
| 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) |
| tdep->in_solib_call_trampoline = hppa32_hpux_in_solib_call_trampoline; |
| else |
| tdep->in_solib_call_trampoline = 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); |
| |
| set_gdbarch_push_dummy_code (gdbarch, hppa_hpux_push_dummy_code); |
| set_gdbarch_call_dummy_location (gdbarch, ON_STACK); |
| |
| frame_unwind_append_sniffer (gdbarch, hppa_hpux_sigtramp_unwind_sniffer); |
| |
| observer_attach_inferior_created (hppa_hpux_inferior_created); |
| } |
| |
| 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; |
| |
| tdep->find_global_pointer = hppa_hpux_som_find_global_pointer; |
| 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); |
| } |