/* Perform an inferior function call, for GDB, the GNU debugger. Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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 "breakpoint.h" #include "target.h" #include "regcache.h" #include "inferior.h" #include "gdb_assert.h" #include "block.h" #include "gdbcore.h" #include "language.h" #include "objfiles.h" #include "gdbcmd.h" #include "command.h" #include "gdb_string.h" #include "infcall.h" #if defined (NM_NEXTSTEP) #include "macosx-nat-infthread.h" /* Whether to allow inferior function calls to be made or not. translated processes cannot do inferior function calls (or changing the PC in any way) and can terminate the inferior if you try. */ int inferior_function_calls_disabled_p = 0; #endif /* NOTE: cagney/2003-04-16: What's the future of this code? GDB needs an asynchronous expression evaluator, that means an asynchronous inferior function call implementation, and that in turn means restructuring the code so that it is event driven. */ /* How you should pass arguments to a function depends on whether it was defined in K&R style or prototype style. If you define a function using the K&R syntax that takes a `float' argument, then callers must pass that argument as a `double'. If you define the function using the prototype syntax, then you must pass the argument as a `float', with no promotion. Unfortunately, on certain older platforms, the debug info doesn't indicate reliably how each function was defined. A function type's TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was defined in prototype style. When calling a function whose TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to decide what to do. For modern targets, it is proper to assume that, if the prototype flag is clear, that can be trusted: `float' arguments should be promoted to `double'. For some older targets, if the prototype flag is clear, that doesn't tell us anything. The default is to trust the debug information; the user can override this behavior with "set coerce-float-to-double 0". */ static int coerce_float_to_double_p = 1; /* This boolean tells what gdb should do if a signal is received while in a function called from gdb (call dummy). If set, gdb unwinds the stack and restore the context to what as it was before the call. The default is to stop in the frame where the signal was received. */ int unwind_on_signal_p = 0; int set_unwind_on_signal (int new_val) { int old_val = unwind_on_signal_p; unwind_on_signal_p = new_val; return old_val; } /* Perform the standard coercions that are specified for arguments to be passed to C functions. If PARAM_TYPE is non-NULL, it is the expected parameter type. IS_PROTOTYPED is non-zero if the function declaration is prototyped. */ static struct value * value_arg_coerce (struct value *arg, struct type *param_type, int is_prototyped) { struct type *arg_type = check_typedef (VALUE_TYPE (arg)); struct type *type = param_type ? check_typedef (param_type) : arg_type; switch (TYPE_CODE (type)) { case TYPE_CODE_REF: if (TYPE_CODE (arg_type) != TYPE_CODE_REF && TYPE_CODE (arg_type) != TYPE_CODE_PTR) { arg = value_addr (arg); VALUE_TYPE (arg) = param_type; return arg; } break; case TYPE_CODE_INT: case TYPE_CODE_CHAR: case TYPE_CODE_BOOL: case TYPE_CODE_ENUM: /* If we don't have a prototype, coerce to integer type if necessary. */ if (!is_prototyped) { if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int)) type = builtin_type_int; } /* Currently all target ABIs require at least the width of an integer type for an argument. We may have to conditionalize the following type coercion for future targets. */ if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int)) type = builtin_type_int; break; case TYPE_CODE_FLT: if (!is_prototyped && coerce_float_to_double_p) { if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double)) type = builtin_type_double; else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double)) type = builtin_type_long_double; } break; case TYPE_CODE_FUNC: type = lookup_pointer_type (type); break; case TYPE_CODE_ARRAY: /* Arrays are coerced to pointers to their first element, unless they are vectors, in which case we want to leave them alone, because they are passed by value. */ if (current_language->c_style_arrays) if (!TYPE_VECTOR (type)) type = lookup_pointer_type (TYPE_TARGET_TYPE (type)); break; case TYPE_CODE_UNDEF: case TYPE_CODE_PTR: case TYPE_CODE_STRUCT: case TYPE_CODE_UNION: case TYPE_CODE_VOID: case TYPE_CODE_SET: case TYPE_CODE_RANGE: case TYPE_CODE_STRING: case TYPE_CODE_BITSTRING: case TYPE_CODE_ERROR: case TYPE_CODE_MEMBER: case TYPE_CODE_METHOD: case TYPE_CODE_COMPLEX: default: break; } return value_cast (type, arg); } /* Determine a function's address and its return type from its value. Calls error() if the function is not valid for calling. */ CORE_ADDR find_function_addr (struct value *function, struct type **retval_type) { struct type *ftype = check_typedef (VALUE_TYPE (function)); enum type_code code = TYPE_CODE (ftype); struct type *value_type; CORE_ADDR funaddr; /* If it's a member function, just look at the function part of it. */ /* Determine address to call. */ if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD) { funaddr = VALUE_ADDRESS (function); value_type = TYPE_TARGET_TYPE (ftype); } else if (code == TYPE_CODE_PTR) { funaddr = value_as_address (function); ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); if (TYPE_CODE (ftype) == TYPE_CODE_FUNC || TYPE_CODE (ftype) == TYPE_CODE_METHOD) { funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, funaddr, ¤t_target); value_type = TYPE_TARGET_TYPE (ftype); } else value_type = builtin_type_int; } else if (code == TYPE_CODE_INT) { /* Handle the case of functions lacking debugging info. Their values are characters since their addresses are char */ if (TYPE_LENGTH (ftype) == 1) funaddr = value_as_address (value_addr (function)); else /* Handle integer used as address of a function. */ funaddr = (CORE_ADDR) value_as_long (function); value_type = builtin_type_int; } else if (code == TYPE_CODE_ERROR) { value_type = builtin_type_error; } else error ("Invalid data type for function to be called."); *retval_type = value_type; return funaddr; } /* Call breakpoint_auto_delete on the current contents of the bpstat pointed to by arg (which is really a bpstat *). */ static void breakpoint_auto_delete_contents (void *arg) { breakpoint_auto_delete (*(bpstat *) arg); } static CORE_ADDR legacy_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc, struct value **args, int nargs, struct type *value_type, CORE_ADDR *real_pc, CORE_ADDR *bp_addr) { /* CALL_DUMMY is an array of words (DEPRECATED_REGISTER_SIZE), but each word is in host byte order. Before calling DEPRECATED_FIX_CALL_DUMMY, we byteswap it and remove any extra bytes which might exist because ULONGEST is bigger than DEPRECATED_REGISTER_SIZE. */ /* NOTE: This is pretty wierd, as the call dummy is actually a sequence of instructions. But CISC machines will have to pack the instructions into DEPRECATED_REGISTER_SIZE units (and so will RISC machines for which INSTRUCTION_SIZE is not DEPRECATED_REGISTER_SIZE). */ /* NOTE: This is pretty stupid. CALL_DUMMY should be in strict target byte order. */ CORE_ADDR start_sp; ULONGEST *dummy = alloca (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS); int sizeof_dummy1 = (DEPRECATED_REGISTER_SIZE * DEPRECATED_SIZEOF_CALL_DUMMY_WORDS / sizeof (ULONGEST)); char *dummy1 = alloca (sizeof_dummy1); memcpy (dummy, DEPRECATED_CALL_DUMMY_WORDS, DEPRECATED_SIZEOF_CALL_DUMMY_WORDS); if (INNER_THAN (1, 2)) { /* Stack grows down */ sp -= sizeof_dummy1; start_sp = sp; } else { /* Stack grows up */ start_sp = sp; sp += sizeof_dummy1; } /* NOTE: cagney/2002-09-10: Don't bother re-adjusting the stack after allocating space for the call dummy. A target can specify a SIZEOF_DUMMY1 (via DEPRECATED_SIZEOF_CALL_DUMMY_WORDS) such that all local alignment requirements are met. */ /* Create a call sequence customized for this function and the number of arguments for it. */ { int i; for (i = 0; i < (int) (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0])); i++) store_unsigned_integer (&dummy1[i * DEPRECATED_REGISTER_SIZE], DEPRECATED_REGISTER_SIZE, (ULONGEST) dummy[i]); } /* NOTE: cagney/2003-04-22: This computation of REAL_PC, BP_ADDR and DUMMY_ADDR is pretty messed up. It comes from constant tinkering with the values. Instead a DEPRECATED_FIX_CALL_DUMMY replacement (PUSH_DUMMY_BREAKPOINT?) should just do everything. */ if (!gdbarch_push_dummy_call_p (current_gdbarch)) { #ifdef GDB_TARGET_IS_HPPA (*real_pc) = DEPRECATED_FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args, value_type, using_gcc); #else if (DEPRECATED_FIX_CALL_DUMMY_P ()) { /* gdb_assert (CALL_DUMMY_LOCATION == ON_STACK) true? */ DEPRECATED_FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args, value_type, using_gcc); } (*real_pc) = start_sp; #endif } /* Yes, the offset is applied to the real_pc and not the dummy addr. Ulgh! Blame the HP/UX target. */ (*bp_addr) = (*real_pc) + DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET; /* Yes, the offset is applied to the real_pc and not the dummy_addr. Ulgh! Blame the HP/UX target. */ (*real_pc) += DEPRECATED_CALL_DUMMY_START_OFFSET; write_memory (start_sp, (char *) dummy1, sizeof_dummy1); if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES) generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1); return sp; } static CORE_ADDR generic_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc, struct value **args, int nargs, struct type *value_type, CORE_ADDR *real_pc, CORE_ADDR *bp_addr) { /* Something here to findout the size of a breakpoint and then allocate space for it on the stack. */ int bplen; /* This code assumes frame align. */ gdb_assert (gdbarch_frame_align_p (gdbarch)); /* Force the stack's alignment. The intent is to ensure that the SP is aligned to at least a breakpoint instruction's boundary. */ sp = gdbarch_frame_align (gdbarch, sp); /* Allocate space for, and then position the breakpoint on the stack. */ if (gdbarch_inner_than (gdbarch, 1, 2)) { CORE_ADDR bppc = sp; gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen); sp = gdbarch_frame_align (gdbarch, sp - bplen); (*bp_addr) = sp; /* Should the breakpoint size/location be re-computed here? */ } else { (*bp_addr) = sp; gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen); sp = gdbarch_frame_align (gdbarch, sp + bplen); } /* Inferior resumes at the function entry point. */ (*real_pc) = funaddr; return sp; } /* Provide backward compatibility. Once DEPRECATED_FIX_CALL_DUMMY is eliminated, this can be simplified. */ static CORE_ADDR push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc, struct value **args, int nargs, struct type *value_type, CORE_ADDR *real_pc, CORE_ADDR *bp_addr) { if (gdbarch_push_dummy_code_p (gdbarch)) return gdbarch_push_dummy_code (gdbarch, sp, funaddr, using_gcc, args, nargs, value_type, real_pc, bp_addr); else if (DEPRECATED_FIX_CALL_DUMMY_P () && !gdbarch_push_dummy_call_p (gdbarch)) return legacy_push_dummy_code (gdbarch, sp, funaddr, using_gcc, args, nargs, value_type, real_pc, bp_addr); else return generic_push_dummy_code (gdbarch, sp, funaddr, using_gcc, args, nargs, value_type, real_pc, bp_addr); } /* All this stuff with a dummy frame may seem unnecessarily complicated (why not just save registers in GDB?). The purpose of pushing a dummy frame which looks just like a real frame is so that if you call a function and then hit a breakpoint (get a signal, etc), "backtrace" will look right. Whether the backtrace needs to actually show the stack at the time the inferior function was called is debatable, but it certainly needs to not display garbage. So if you are contemplating making dummy frames be different from normal frames, consider that. */ /* Perform a function call in the inferior. ARGS is a vector of values of arguments (NARGS of them). FUNCTION is a value, the function to be called. Returns a value representing what the function returned. May fail to return, if a breakpoint or signal is hit during the execution of the function. ARGS is modified to contain coerced values. */ struct value * hand_function_call (struct value *function, struct type *expect_type, int nargs, struct value **args, int restore_frame) { CORE_ADDR sp; CORE_ADDR dummy_addr; struct type *value_type; unsigned char struct_return; CORE_ADDR struct_addr = 0; struct regcache *retbuf; struct cleanup *retbuf_cleanup; struct inferior_status *inf_status; struct cleanup *inf_status_cleanup; CORE_ADDR funaddr; int using_gcc; /* Set to version of gcc in use, or zero if not gcc */ CORE_ADDR real_pc; struct type *ftype = check_typedef (SYMBOL_TYPE (function)); CORE_ADDR bp_addr; if (!target_has_execution) noprocess (); funaddr = find_function_addr (function, &value_type); CHECK_TYPEDEF (value_type); /* We don't require expect_type not to be a typedef, so remember to run check_typedef here */ if ((value_type == NULL) || (TYPE_CODE (value_type) == TYPE_CODE_ERROR)) if (expect_type != NULL) value_type = check_typedef (expect_type); if ((value_type == NULL) || (TYPE_CODE (value_type) == TYPE_CODE_ERROR)) error ("Unable to call function at 0x%lx: no return type information available.\n" "To call this function anyway, you can cast the return type explicitly (e.g. 'print (float) fabs (3.0)')", (unsigned long) funaddr); /* Create a cleanup chain that contains the retbuf (buffer containing the register values). This chain is create BEFORE the inf_status chain so that the inferior status can cleaned up (restored or discarded) without having the retbuf freed. */ retbuf = regcache_xmalloc (current_gdbarch); retbuf_cleanup = make_cleanup_regcache_xfree (retbuf); #if defined (NM_NEXTSTEP) macosx_setup_registers_before_hand_call (); /* FIXME: This really needs to go in the target vector.... */ if (inferior_function_calls_disabled_p) error ("Function calls from gdb not possible when debugging translated processes."); #endif /* A cleanup for the inferior status. Create this AFTER the retbuf so that this can be discarded or applied without interfering with the regbuf. */ inf_status = save_inferior_status (1); inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status); if (DEPRECATED_PUSH_DUMMY_FRAME_P ()) { /* DEPRECATED_PUSH_DUMMY_FRAME is responsible for saving the inferior registers (and frame_pop() for restoring them). (At least on most machines) they are saved on the stack in the inferior. */ DEPRECATED_PUSH_DUMMY_FRAME; } else { /* FIXME: cagney/2003-02-26: Step zero of this little tinker is to extract the generic dummy frame code from the architecture vector. Hence this direct call. A follow-on change is to modify this interface so that it takes thread OR frame OR ptid as a parameter, and returns a dummy frame handle. The handle can then be used further down as a parameter to generic_save_dummy_frame_tos(). Hmm, thinking about it, since everything is ment to be using generic dummy frames, why not even use some of the dummy frame code to here - do a regcache dup and then pass the duped regcache, along with all the other stuff, at one single point. In fact, you can even save the structure's return address in the dummy frame and fix one of those nasty lost struct return edge conditions. */ generic_push_dummy_frame (); } /* Ensure that the initial SP is correctly aligned. */ { CORE_ADDR old_sp = read_sp (); if (gdbarch_frame_align_p (current_gdbarch)) { sp = gdbarch_frame_align (current_gdbarch, old_sp); /* NOTE: cagney/2003-08-13: Skip the "red zone". For some ABIs, a function can use memory beyond the inner most stack address. AMD64 called that region the "red zone". Skip at least the "red zone" size before allocating any space on the stack. */ if (INNER_THAN (1, 2)) sp -= gdbarch_frame_red_zone_size (current_gdbarch); else sp += gdbarch_frame_red_zone_size (current_gdbarch); /* Still aligned? */ gdb_assert (sp == gdbarch_frame_align (current_gdbarch, sp)); /* NOTE: cagney/2002-09-18: On a RISC architecture, a void parameterless generic dummy frame (i.e., no parameters, no result) typically does not need to push anything the stack and hence can leave SP and FP. Similarly, a frameless (possibly leaf) function does not push anything on the stack and, hence, that too can leave FP and SP unchanged. As a consequence, a sequence of void parameterless generic dummy frame calls to frameless functions will create a sequence of effectively identical frames (SP, FP and TOS and PC the same). This, not suprisingly, results in what appears to be a stack in an infinite loop --- when GDB tries to find a generic dummy frame on the internal dummy frame stack, it will always find the first one. To avoid this problem, the code below always grows the stack. That way, two dummy frames can never be identical. It does burn a few bytes of stack but that is a small price to pay :-). */ if (sp == old_sp) { if (INNER_THAN (1, 2)) /* Stack grows down. */ sp = gdbarch_frame_align (current_gdbarch, old_sp - 1); else /* Stack grows up. */ sp = gdbarch_frame_align (current_gdbarch, old_sp + 1); } gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp) || (INNER_THAN (2, 1) && sp >= old_sp)); } else /* FIXME: cagney/2002-09-18: Hey, you loose! Who knows how badly aligned the SP is! If the generic dummy frame ends up empty (because nothing is pushed) GDB won't be able to correctly perform back traces. If a target is having trouble with backtraces, first thing to do is add FRAME_ALIGN() to the architecture vector. If that fails, try unwind_dummy_id(). If the ABI specifies a "Red Zone" (see the doco) the code below will quietly trash it. */ sp = old_sp; } { struct block *b = block_for_pc (funaddr); /* If compiled without -g, assume GCC 2. */ using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b)); } /* Are we returning a value using a structure return or a normal value return? */ struct_return = using_struct_return (value_type, using_gcc); /* Determine the location of the breakpoint (and possibly other stuff) that the called function will return to. The SPARC, for a function returning a structure or union, needs to make space for not just the breakpoint but also an extra word containing the size (?) of the structure being passed. */ /* The actual breakpoint (at BP_ADDR) is inserted separatly so there is no need to write that out. */ switch (CALL_DUMMY_LOCATION) { case ON_STACK: /* "dummy_addr" is here just to keep old targets happy. New targets return that same information via "sp" and "bp_addr". */ if (INNER_THAN (1, 2)) { sp = push_dummy_code (current_gdbarch, sp, funaddr, using_gcc, args, nargs, value_type, &real_pc, &bp_addr); dummy_addr = sp; } else { dummy_addr = sp; sp = push_dummy_code (current_gdbarch, sp, funaddr, using_gcc, args, nargs, value_type, &real_pc, &bp_addr); } break; case AT_ENTRY_POINT: if (DEPRECATED_FIX_CALL_DUMMY_P () && !gdbarch_push_dummy_call_p (current_gdbarch)) { /* Sigh. Some targets use DEPRECATED_FIX_CALL_DUMMY to shove extra stuff onto the stack or into registers. That code should be in PUSH_DUMMY_CALL, however, in the mean time ... */ /* If the target is manipulating DUMMY1, it looses big time. */ void *dummy1 = NULL; DEPRECATED_FIX_CALL_DUMMY (dummy1, sp, funaddr, nargs, args, value_type, using_gcc); } real_pc = funaddr; dummy_addr = entry_point_address (); /* Make certain that the address points at real code, and not a function descriptor. */ dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, dummy_addr, ¤t_target); /* A call dummy always consists of just a single breakpoint, so it's address is the same as the address of the dummy. */ bp_addr = dummy_addr; break; case AT_SYMBOL: /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose address is the location where the breakpoint should be placed. Once all targets are using the overhauled frame code this can be deleted - ON_STACK is a better option. */ { struct minimal_symbol *sym; sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL); real_pc = funaddr; if (sym) dummy_addr = SYMBOL_VALUE_ADDRESS (sym); else dummy_addr = entry_point_address (); /* Make certain that the address points at real code, and not a function descriptor. */ dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, dummy_addr, ¤t_target); /* A call dummy always consists of just a single breakpoint, so it's address is the same as the address of the dummy. */ bp_addr = dummy_addr; break; } default: internal_error (__FILE__, __LINE__, "bad switch"); } if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES) /* Save where the breakpoint is going to be inserted so that the dummy-frame code is later able to re-identify it. */ generic_save_call_dummy_addr (bp_addr, bp_addr + 1); if (nargs < TYPE_NFIELDS (ftype)) error ("too few arguments in function call"); { int i; for (i = nargs - 1; i >= 0; i--) { int prototyped; struct type *param_type; /* FIXME drow/2002-05-31: Should just always mark methods as prototyped. Can we respect TYPE_VARARGS? Probably not. */ if (TYPE_CODE (ftype) == TYPE_CODE_METHOD) prototyped = 1; else if (i < TYPE_NFIELDS (ftype)) prototyped = TYPE_PROTOTYPED (ftype); else prototyped = 0; if (i < TYPE_NFIELDS (ftype)) param_type = TYPE_FIELD_TYPE (ftype, i); else param_type = NULL; args[i] = value_arg_coerce (args[i], param_type, prototyped); /* elz: this code is to handle the case in which the function to be called has a pointer to function as parameter and the corresponding actual argument is the address of a function and not a pointer to function variable. In aCC compiled code, the calls through pointers to functions (in the body of the function called by hand) are made via $$dyncall_external which requires some registers setting, this is taken care of if we call via a function pointer variable, but not via a function address. In cc this is not a problem. */ if (using_gcc == 0) { if (param_type != NULL && TYPE_CODE (ftype) != TYPE_CODE_METHOD) { /* if this parameter is a pointer to function. */ if (TYPE_CODE (param_type) == TYPE_CODE_PTR) if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC) /* elz: FIXME here should go the test about the compiler used to compile the target. We want to issue the error message only if the compiler used was HP's aCC. If we used HP's cc, then there is no problem and no need to return at this point. */ /* Go see if the actual parameter is a variable of type pointer to function or just a function. */ if (args[i]->lval == not_lval) { char *arg_name; if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL)) error ("\ You cannot use function <%s> as argument. \n\ You must use a pointer to function type variable. Command ignored.", arg_name); } } } } } if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ()) { int i; /* This is a machine like the sparc, where we may need to pass a pointer to the structure, not the structure itself. */ for (i = nargs - 1; i >= 0; i--) { struct type *arg_type = check_typedef (VALUE_TYPE (args[i])); if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT || TYPE_CODE (arg_type) == TYPE_CODE_UNION || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY || TYPE_CODE (arg_type) == TYPE_CODE_STRING || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING || TYPE_CODE (arg_type) == TYPE_CODE_SET || (TYPE_CODE (arg_type) == TYPE_CODE_FLT && TYPE_LENGTH (arg_type) > 8) ) && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc, arg_type)) { CORE_ADDR addr; int len; /* = TYPE_LENGTH (arg_type); */ int aligned_len; arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i])); len = TYPE_LENGTH (arg_type); if (DEPRECATED_STACK_ALIGN_P ()) /* MVS 11/22/96: I think at least some of this stack_align code is really broken. Better to let PUSH_ARGUMENTS adjust the stack in a target-defined manner. */ aligned_len = DEPRECATED_STACK_ALIGN (len); else aligned_len = len; if (INNER_THAN (1, 2)) { /* stack grows downward */ sp -= aligned_len; /* ... so the address of the thing we push is the stack pointer after we push it. */ addr = sp; } else { /* The stack grows up, so the address of the thing we push is the stack pointer before we push it. */ addr = sp; sp += aligned_len; } /* Push the structure. */ write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len); /* The value we're going to pass is the address of the thing we just pushed. */ /*args[i] = value_from_longest (lookup_pointer_type (value_type), (LONGEST) addr); */ args[i] = value_from_pointer (lookup_pointer_type (arg_type), addr); } } } /* Reserve space for the return structure to be written on the stack, if necessary. Make certain that the value is correctly aligned. */ if (struct_return) { int len = TYPE_LENGTH (value_type); if (DEPRECATED_STACK_ALIGN_P ()) /* NOTE: cagney/2003-03-22: Should rely on frame align, rather than stack align to force the alignment of the stack. */ len = DEPRECATED_STACK_ALIGN (len); if (INNER_THAN (1, 2)) { /* Stack grows downward. Align STRUCT_ADDR and SP after making space for the return value. */ sp -= len; if (gdbarch_frame_align_p (current_gdbarch)) sp = gdbarch_frame_align (current_gdbarch, sp); struct_addr = sp; } else { /* Stack grows upward. Align the frame, allocate space, and then again, re-align the frame??? */ if (gdbarch_frame_align_p (current_gdbarch)) sp = gdbarch_frame_align (current_gdbarch, sp); struct_addr = sp; sp += len; if (gdbarch_frame_align_p (current_gdbarch)) sp = gdbarch_frame_align (current_gdbarch, sp); } } /* Create the dummy stack frame. Pass in the call dummy address as, presumably, the ABI code knows where, in the call dummy, the return address should be pointed. */ if (gdbarch_push_dummy_call_p (current_gdbarch)) /* When there is no push_dummy_call method, should this code simply error out. That would the implementation of this method for all ABIs (which is probably a good thing). */ sp = gdbarch_push_dummy_call (current_gdbarch, funaddr, current_regcache, bp_addr, nargs, args, sp, struct_return, struct_addr); else if (DEPRECATED_PUSH_ARGUMENTS_P ()) /* Keep old targets working. */ sp = DEPRECATED_PUSH_ARGUMENTS (nargs, args, sp, struct_return, struct_addr); else sp = legacy_push_arguments (nargs, args, sp, struct_return, struct_addr); if (DEPRECATED_PUSH_RETURN_ADDRESS_P ()) /* for targets that use no CALL_DUMMY */ /* There are a number of targets now which actually don't write any CALL_DUMMY instructions into the target, but instead just save the machine state, push the arguments, and jump directly to the callee function. Since this doesn't actually involve executing a JSR/BSR instruction, the return address must be set up by hand, either by pushing onto the stack or copying into a return-address register as appropriate. Formerly this has been done in PUSH_ARGUMENTS, but that's overloading its functionality a bit, so I'm making it explicit to do it here. */ /* NOTE: cagney/2003-04-22: The first parameter ("real_pc") has been replaced with zero, it turns out that no implementation used that parameter. This occured because the value being supplied - the address of the called function's entry point instead of the address of the breakpoint that the called function should return to - wasn't useful. */ sp = DEPRECATED_PUSH_RETURN_ADDRESS (0, sp); /* NOTE: cagney/2003-03-23: Diable this code when there is a push_dummy_call() method. Since that method will have already handled any alignment issues, the code below is entirely redundant. */ if (!gdbarch_push_dummy_call_p (current_gdbarch) && DEPRECATED_STACK_ALIGN_P () && !INNER_THAN (1, 2)) { /* If stack grows up, we must leave a hole at the bottom, note that sp already has been advanced for the arguments! */ sp = DEPRECATED_STACK_ALIGN (sp); } /* Store the address at which the structure is supposed to be written. */ /* NOTE: 2003-03-24: Since PUSH_ARGUMENTS can (and typically does) store the struct return address, this call is entirely redundant. */ if (struct_return && DEPRECATED_STORE_STRUCT_RETURN_P ()) DEPRECATED_STORE_STRUCT_RETURN (struct_addr, sp); /* Write the stack pointer. This is here because the statements above might fool with it. On SPARC, this write also stores the register window into the right place in the new stack frame, which otherwise wouldn't happen (see store_inferior_registers in sparc-nat.c). */ /* NOTE: cagney/2003-03-23: Since the architecture method push_dummy_call() should have already stored the stack pointer (as part of creating the fake call frame), and none of the code following that call adjusts the stack-pointer value, the below call is entirely redundant. */ if (DEPRECATED_DUMMY_WRITE_SP_P ()) DEPRECATED_DUMMY_WRITE_SP (sp); if (gdbarch_unwind_dummy_id_p (current_gdbarch)) { /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by unwind_dummy_id to form the frame ID's stack address. */ gdb_assert (DEPRECATED_USE_GENERIC_DUMMY_FRAMES); generic_save_dummy_frame_tos (sp); } else if (DEPRECATED_SAVE_DUMMY_FRAME_TOS_P ()) DEPRECATED_SAVE_DUMMY_FRAME_TOS (sp); /* Now proceed, having reached the desired place. */ clear_proceed_status (); /* Create a momentary breakpoint at the return address of the inferior. That way it breaks when it returns. */ { struct breakpoint *bpt; struct symtab_and_line sal; struct frame_id frame; init_sal (&sal); /* initialize to zeroes */ sal.pc = bp_addr; sal.section = find_pc_overlay (sal.pc); /* Set up a frame ID for the dummy frame so we can pass it to set_momentary_breakpoint. We need to give the breakpoint a frame ID so that the breakpoint code can correctly re-identify the dummy breakpoint. */ if (gdbarch_unwind_dummy_id_p (current_gdbarch)) { /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by unwind_dummy_id to form the frame ID's stack address. */ gdb_assert (DEPRECATED_USE_GENERIC_DUMMY_FRAMES); frame = frame_id_build (sp, sal.pc); } else { /* The assumption here is that push_dummy_call() returned the stack part of the frame ID. Unfortunately, many older architectures were, via a convoluted mess, relying on the poorly defined and greatly overloaded DEPRECATED_TARGET_READ_FP or DEPRECATED_FP_REGNUM to supply the value. */ if (DEPRECATED_TARGET_READ_FP_P ()) frame = frame_id_build (DEPRECATED_TARGET_READ_FP (), sal.pc); else if (DEPRECATED_FP_REGNUM >= 0) frame = frame_id_build (read_register (DEPRECATED_FP_REGNUM), sal.pc); else frame = frame_id_build (sp, sal.pc); } bpt = set_momentary_breakpoint (sal, frame, bp_call_dummy); bpt->disposition = disp_del; } /* Execute a "stack dummy", a piece of code stored in the stack by the debugger to be executed in the inferior. The dummy's frame is automatically popped whenever that break is hit. If that is the first time the program stops, call_function_by_hand returns to its caller with that frame already gone and sets RC to 0. Otherwise, set RC to a non-zero value. If the called function receives a random signal, we do not allow the user to continue executing it as this may not work. The dummy frame is poped and we return 1. If we hit a breakpoint, we leave the frame in place and return 2 (the frame will eventually be popped when we do hit the dummy end breakpoint). */ { struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0); int saved_async = 0; /* If all error()s out of proceed ended up calling normal_stop (and perhaps they should; it already does in the special case of error out of resume()), then we wouldn't need this. */ make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat); disable_watchpoints_before_interactive_call_start (); proceed_to_finish = 1; /* We want stop_registers, please... */ if (target_can_async_p ()) saved_async = target_async_mask (0); proceed (real_pc, TARGET_SIGNAL_0, 0); if (saved_async) target_async_mask (saved_async); enable_watchpoints_after_interactive_call_stop (); discard_cleanups (old_cleanups); } if (stopped_by_random_signal || !stop_stack_dummy) { /* Find the name of the function we're about to complain about. */ const char *name = NULL; { struct symbol *symbol = find_pc_function (funaddr); if (symbol) name = SYMBOL_PRINT_NAME (symbol); else { /* Try the minimal symbols. */ struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr); if (msymbol) name = SYMBOL_PRINT_NAME (msymbol); } if (name == NULL) { /* Can't use a cleanup here. It is discarded, instead use an alloca. */ char *tmp = xstrprintf ("at %s", local_hex_string (funaddr)); char *a = alloca (strlen (tmp) + 1); strcpy (a, tmp); xfree (tmp); name = a; } } if (stopped_by_random_signal) { /* We stopped inside the FUNCTION because of a random signal. Further execution of the FUNCTION is not allowed. */ if (unwind_on_signal_p) { /* The user wants the context restored. */ /* We must get back to the frame we were before the dummy call. */ frame_pop (get_current_frame ()); /* FIXME: Insert a bunch of wrap_here; name can be very long if it's a C++ name with arguments and stuff. */ error ("\ The program being debugged was signaled while in a function called from GDB.\n\ GDB has restored the context to what it was before the call.\n\ To change this behavior use \"set unwindonsignal off\"\n\ Evaluation of the expression containing the function (%s) will be abandoned.", name); } else { /* The user wants to stay in the frame where we stopped (default).*/ /* If we restored the inferior status (via the cleanup), we would print a spurious error message (Unable to restore previously selected frame), would write the registers from the inf_status (which is wrong), and would do other wrong things. */ discard_cleanups (inf_status_cleanup); discard_inferior_status (inf_status); /* FIXME: Insert a bunch of wrap_here; name can be very long if it's a C++ name with arguments and stuff. */ error ("\ The program being debugged was signaled while in a function called from GDB.\n\ GDB remains in the frame where the signal was received.\n\ To change this behavior use \"set unwindonsignal on\"\n\ Evaluation of the expression containing the function (%s) will be abandoned.", name); } } if (!stop_stack_dummy) { /* We hit a breakpoint inside the FUNCTION. */ /* If we restored the inferior status (via the cleanup), we would print a spurious error message (Unable to restore previously selected frame), would write the registers from the inf_status (which is wrong), and would do other wrong things. */ discard_cleanups (inf_status_cleanup); discard_inferior_status (inf_status); /* The following error message used to say "The expression which contained the function call has been discarded." It is a hard concept to explain in a few words. Ideally, GDB would be able to resume evaluation of the expression when the function finally is done executing. Perhaps someday this will be implemented (it would not be easy). */ /* FIXME: Insert a bunch of wrap_here; name can be very long if it's a C++ name with arguments and stuff. */ error ("\ The program being debugged stopped while in a function called from GDB.\n\ When the function (%s) is done executing, GDB will silently\n\ stop (instead of continuing to evaluate the expression containing\n\ the function call).", name); } /* The above code errors out, so ... */ internal_error (__FILE__, __LINE__, "... should not be here"); } /* If we get here the called FUNCTION run to completion. */ /* On normal return, the stack dummy has been popped already. */ regcache_cpy_no_passthrough (retbuf, stop_registers); /* Restore the inferior status, via its cleanup. At this stage, leave the RETBUF alone. */ do_cleanups (inf_status_cleanup); /* Figure out the value returned by the function. */ if (struct_return) { /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL has correctly stored STRUCT_ADDR in the target. In the past that hasn't been the case, the old MIPS PUSH_ARGUMENTS (PUSH_DUMMY_CALL precursor) would silently move the location of the struct return value making STRUCT_ADDR bogus. If you're seeing problems with values being returned using the "struct return convention", check that PUSH_DUMMY_CALL isn't playing tricks. */ struct value *retval = value_at (value_type, struct_addr, NULL); do_cleanups (retbuf_cleanup); return retval; } else { /* The non-register case was handled above. */ struct value *retval = register_value_being_returned (value_type, retbuf); do_cleanups (retbuf_cleanup); return retval; } } struct value * call_function_by_hand (struct value *function, int nargs, struct value **args) { return hand_function_call (function, NULL, nargs, args, 1); } struct value * call_function_by_hand_expecting_type (struct value *function, struct type *expect_type, int nargs, struct value **args, int restore_frame) { return hand_function_call (function, expect_type, nargs, args, restore_frame); } void _initialize_infcall (void); void _initialize_infcall (void) { add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure, &coerce_float_to_double_p, "\ Set coercion of floats to doubles when calling functions\n\ Variables of type float should generally be converted to doubles before\n\ calling an unprototyped function, and left alone when calling a prototyped\n\ function. However, some older debug info formats do not provide enough\n\ information to determine that a function is prototyped. If this flag is\n\ set, GDB will perform the conversion for a function it considers\n\ unprototyped.\n\ The default is to perform the conversion.\n", "\ Show coercion of floats to doubles when calling functions\n\ Variables of type float should generally be converted to doubles before\n\ calling an unprototyped function, and left alone when calling a prototyped\n\ function. However, some older debug info formats do not provide enough\n\ information to determine that a function is prototyped. If this flag is\n\ set, GDB will perform the conversion for a function it considers\n\ unprototyped.\n\ The default is to perform the conversion.\n", NULL, NULL, &setlist, &showlist); add_setshow_boolean_cmd ("unwindonsignal", no_class, &unwind_on_signal_p, "\ Set unwinding of stack if a signal is received while in a call dummy.\n\ The unwindonsignal lets the user determine what gdb should do if a signal\n\ is received while in a function called from gdb (call dummy). If set, gdb\n\ unwinds the stack and restore the context to what as it was before the call.\n\ The default is to stop in the frame where the signal was received.", "\ Set unwinding of stack if a signal is received while in a call dummy.\n\ The unwindonsignal lets the user determine what gdb should do if a signal\n\ is received while in a function called from gdb (call dummy). If set, gdb\n\ unwinds the stack and restore the context to what as it was before the call.\n\ The default is to stop in the frame where the signal was received.", NULL, NULL, &setlist, &showlist); }