$OpenBSD: pp-gcc_protector_c,v 1.1 2005/01/04 23:06:33 espie Exp $ --- gcc/protector.c.orig Mon Jan 3 10:17:42 2005 +++ gcc/protector.c Mon Jan 3 10:17:42 2005 @@ -0,0 +1,2722 @@ +/* RTL buffer overflow protection function for GNU C compiler + Copyright (C) 1987, 88, 89, 92-7, 1998 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC 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, or (at your option) any later +version. + +GCC 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 GCC; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA +02111-1307, USA. */ + +#include "config.h" +#include "system.h" +#include "machmode.h" + +#include "rtl.h" +#include "tree.h" +#include "regs.h" +#include "flags.h" +#include "insn-config.h" +#include "insn-flags.h" +#include "expr.h" +#include "output.h" +#include "recog.h" +#include "hard-reg-set.h" +#include "real.h" +#include "except.h" +#include "function.h" +#include "toplev.h" +#include "conditions.h" +#include "insn-attr.h" +#include "c-tree.h" +#include "optabs.h" +#include "reload.h" +#include "protector.h" + + +/* Round a value to the lowest integer less than it that is a multiple of + the required alignment. Avoid using division in case the value is + negative. Assume the alignment is a power of two. */ +#define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1)) + +/* Similar, but round to the next highest integer that meets the + alignment. */ +#define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1)) + + +/* Nonzero means use propolice as a stack protection method */ +extern int flag_propolice_protection; + +/* This file contains several memory arrangement functions to protect + the return address and the frame pointer of the stack + from a stack-smashing attack. It also + provides the function that protects pointer variables. */ + +/* Nonzero if function being compiled can define string buffers that may be + damaged by the stack-smash attack */ +static int current_function_defines_vulnerable_string; +static int current_function_defines_short_string; +static int current_function_has_variable_string; +static int current_function_defines_vsized_array; +static int current_function_is_inlinable; +static int is_array; + +static rtx guard_area, _guard; +static rtx function_first_insn, prologue_insert_point; + +/* */ +static HOST_WIDE_INT sweep_frame_offset; +static HOST_WIDE_INT push_allocated_offset = 0; +static HOST_WIDE_INT push_frame_offset = 0; +static int saved_cse_not_expected = 0; + +static int search_string_from_argsandvars PARAMS ((int caller)); +static int search_string_from_local_vars PARAMS ((tree block)); +static int search_pointer_def PARAMS ((tree names)); +static int search_func_pointer PARAMS ((tree type)); +static int check_used_flag PARAMS ((rtx x)); +static void reset_used_flags_for_insns PARAMS ((rtx insn)); +static void reset_used_flags_for_decls PARAMS ((tree block)); +static void reset_used_flags_of_plus PARAMS ((rtx x)); +static void rtl_prologue PARAMS ((rtx insn)); +static void rtl_epilogue PARAMS ((rtx fnlastinsn)); +static void arrange_var_order PARAMS ((tree blocks)); +static void copy_args_for_protection PARAMS ((void)); +static void sweep_string_variable + PARAMS ((rtx sweep_var, HOST_WIDE_INT var_size)); +static void sweep_string_in_decls + PARAMS ((tree block, HOST_WIDE_INT sweep_offset, HOST_WIDE_INT size)); +static void sweep_string_in_args + PARAMS ((tree parms, HOST_WIDE_INT sweep_offset, HOST_WIDE_INT size)); +static void sweep_string_use_of_insns + PARAMS ((rtx insn, HOST_WIDE_INT sweep_offset, HOST_WIDE_INT size)); +static void sweep_string_in_operand + PARAMS ((rtx insn, rtx *loc, + HOST_WIDE_INT sweep_offset, HOST_WIDE_INT size)); +static void move_arg_location + PARAMS ((rtx insn, rtx orig, rtx new, HOST_WIDE_INT var_size)); +static void change_arg_use_of_insns + PARAMS ((rtx insn, rtx orig, rtx *new, HOST_WIDE_INT size)); +static void change_arg_use_of_insns_2 + PARAMS ((rtx insn, rtx orig, rtx *new, HOST_WIDE_INT size)); +static void change_arg_use_in_operand + PARAMS ((rtx insn, rtx x, rtx orig, rtx *new, HOST_WIDE_INT size)); +static void validate_insns_of_varrefs PARAMS ((rtx insn)); +static void validate_operand_of_varrefs PARAMS ((rtx insn, rtx *loc)); + +#define SUSPICIOUS_BUF_SIZE 8 + +#define AUTO_BASEPTR(X) \ + (GET_CODE (X) == PLUS ? XEXP (X, 0) : X) +#define AUTO_OFFSET(X) \ + (GET_CODE (X) == PLUS ? INTVAL (XEXP (X, 1)) : 0) +#undef PARM_PASSED_IN_MEMORY +#define PARM_PASSED_IN_MEMORY(PARM) \ + (GET_CODE (DECL_INCOMING_RTL (PARM)) == MEM) +#define VIRTUAL_STACK_VARS_P(X) \ + ((X) == virtual_stack_vars_rtx || (GET_CODE (X) == REG && (X)->used)) +#define TREE_VISITED(NODE) ((NODE)->common.unused_0) + + + +void +prepare_stack_protection (inlinable) + int inlinable; +{ + tree blocks = DECL_INITIAL (current_function_decl); + current_function_is_inlinable = inlinable && !flag_no_inline; + push_frame_offset = push_allocated_offset = 0; + saved_cse_not_expected = 0; + + /* + skip the protection if the function has no block + or it is an inline function + */ + if (current_function_is_inlinable) validate_insns_of_varrefs (get_insns ()); + if (! blocks || current_function_is_inlinable) return; + + current_function_defines_vulnerable_string + = search_string_from_argsandvars (0); + + if (current_function_defines_vulnerable_string + || flag_stack_protection) + { + HOST_WIDE_INT offset; + function_first_insn = get_insns (); + + if (current_function_contains_functions) { + if (warn_stack_protector) + warning ("not protecting function: it contains functions"); + return; + } + + /* Initialize recognition, indicating that volatile is OK. */ + init_recog (); + + sweep_frame_offset = 0; + +#ifdef STACK_GROWS_DOWNWARD + /* + frame_offset: offset to end of allocated area of stack frame. + It is defined in the function.c + */ + + /* the location must be before buffers */ + guard_area = assign_stack_local (BLKmode, UNITS_PER_GUARD, -1); + PUT_MODE (guard_area, GUARD_m); + MEM_VOLATILE_P (guard_area) = 1; + +#ifndef FRAME_GROWS_DOWNWARD + sweep_frame_offset = frame_offset; +#endif + + /* For making room for guard value, scan all insns and fix the offset + address of the variable that is based on frame pointer. + Scan all declarations of variables and fix the offset address + of the variable that is based on the frame pointer */ + sweep_string_variable (guard_area, UNITS_PER_GUARD); + + + /* the location of guard area moves to the beginning of stack frame */ + if ((offset = AUTO_OFFSET(XEXP (guard_area, 0)))) + XEXP (XEXP (guard_area, 0), 1) + = gen_rtx_CONST_INT (VOIDmode, sweep_frame_offset); + + + /* Insert prologue rtl instructions */ + rtl_prologue (function_first_insn); + + if (! current_function_has_variable_string) + { + /* Generate argument saving instruction */ + copy_args_for_protection (); + +#ifndef FRAME_GROWS_DOWNWARD + /* If frame grows upward, character string copied from an arg + stays top of the guard variable. + So sweep the guard variable again */ + sweep_frame_offset = CEIL_ROUND (frame_offset, + BIGGEST_ALIGNMENT / BITS_PER_UNIT); + sweep_string_variable (guard_area, UNITS_PER_GUARD); +#endif + } + else if (warn_stack_protector) + warning ("not protecting variables: it has a variable length buffer"); +#endif +#ifndef FRAME_GROWS_DOWNWARD + if (STARTING_FRAME_OFFSET == 0) + { + /* this may be only for alpha */ + push_allocated_offset = BIGGEST_ALIGNMENT / BITS_PER_UNIT; + assign_stack_local (BLKmode, push_allocated_offset, -1); + sweep_frame_offset = frame_offset; + sweep_string_variable (const0_rtx, -push_allocated_offset); + sweep_frame_offset = AUTO_OFFSET (XEXP (guard_area, 0)); + } +#endif + + /* Arrange the order of local variables */ + arrange_var_order (blocks); + +#ifdef STACK_GROWS_DOWNWARD + /* Insert epilogue rtl instructions */ + rtl_epilogue (get_last_insn ()); +#endif + init_recog_no_volatile (); + } + else if (current_function_defines_short_string + && warn_stack_protector) + warning ("not protecting function: buffer is less than %d bytes long", + SUSPICIOUS_BUF_SIZE); +} + +/* + search string from arguments and local variables + caller: 0 means call from protector_stack_protection + 1 means call from push_frame +*/ +static int +search_string_from_argsandvars (caller) + int caller; +{ + tree blocks, parms; + int string_p; + + /* saves a latest search result as a cached infomation */ + static tree __latest_search_decl = 0; + static int __latest_search_result = FALSE; + + if (__latest_search_decl == current_function_decl) + return __latest_search_result; + else if (caller) return FALSE; + __latest_search_decl = current_function_decl; + __latest_search_result = TRUE; + + current_function_defines_short_string = FALSE; + current_function_has_variable_string = FALSE; + current_function_defines_vsized_array = FALSE; + + /* + search a string variable from local variables + */ + blocks = DECL_INITIAL (current_function_decl); + string_p = search_string_from_local_vars (blocks); + + if (!current_function_defines_vsized_array && current_function_calls_alloca) + { + current_function_has_variable_string = TRUE; + return TRUE; + } + + if (string_p) return TRUE; + +#ifdef STACK_GROWS_DOWNWARD + /* + search a string variable from arguments + */ + parms = DECL_ARGUMENTS (current_function_decl); + + for (; parms; parms = TREE_CHAIN (parms)) + if (DECL_NAME (parms) && TREE_TYPE (parms) != error_mark_node) + { + if (PARM_PASSED_IN_MEMORY (parms) && DECL_NAME (parms)) + { + string_p = search_string_def (TREE_TYPE(parms)); + if (string_p) return TRUE; + } + } +#endif + + __latest_search_result = FALSE; + return FALSE; +} + + +static int +search_string_from_local_vars (block) + tree block; +{ + tree types; + int found = FALSE; + + while (block && TREE_CODE(block)==BLOCK) + { + types = BLOCK_VARS(block); + + while (types) + { + /* skip the declaration that refers an external variable */ + /* name: types.decl.name.identifier.id */ + if (! DECL_EXTERNAL (types) && ! TREE_STATIC (types) + && TREE_CODE (types) == VAR_DECL + && ! DECL_ARTIFICIAL (types) + && DECL_RTL_SET_P (types) + && GET_CODE (DECL_RTL (types)) == MEM + + && search_string_def (TREE_TYPE (types))) + { + rtx home = DECL_RTL (types); + + if (GET_CODE (home) == MEM + && (GET_CODE (XEXP (home, 0)) == MEM + || + (GET_CODE (XEXP (home, 0)) == REG + && XEXP (home, 0) != virtual_stack_vars_rtx + && REGNO (XEXP (home, 0)) != HARD_FRAME_POINTER_REGNUM + && REGNO (XEXP (home, 0)) != STACK_POINTER_REGNUM +#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM + && REGNO (XEXP (home, 0)) != ARG_POINTER_REGNUM +#endif + ))) + /* If the value is indirect by memory or by a register + that isn't the frame pointer then it means the object is + variable-sized and address through + that register or stack slot. + The protection has no way to hide pointer variables + behind the array, so all we can do is staying + the order of variables and arguments. */ + { + current_function_has_variable_string = TRUE; + } + + /* found character array */ + found = TRUE; + } + + types = TREE_CHAIN(types); + } + + if (search_string_from_local_vars (BLOCK_SUBBLOCKS (block))) + { + found = TRUE; + } + + block = BLOCK_CHAIN (block); + } + + return found; +} + + +/* + * search a character array from the specified type tree + */ +int +search_string_def (type) + tree type; +{ + tree tem; + + if (! type) + return FALSE; + + switch (TREE_CODE (type)) + { + case ARRAY_TYPE: + /* Check if the array is a variable-sized array */ + if (TYPE_DOMAIN (type) == 0 + || (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != 0 + && TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) == NOP_EXPR)) + current_function_defines_vsized_array = TRUE; + + /* TREE_CODE( TREE_TYPE(type) ) == INTEGER_TYPE */ + if (TYPE_MAIN_VARIANT (TREE_TYPE(type)) == char_type_node + || TYPE_MAIN_VARIANT (TREE_TYPE(type)) == signed_char_type_node + || TYPE_MAIN_VARIANT (TREE_TYPE(type)) == unsigned_char_type_node) + { + /* Check if the string is a variable string */ + if (TYPE_DOMAIN (type) == 0 + || + (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != 0 + && TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) == NOP_EXPR)) + return TRUE; + + /* Check if the string size is greater than SUSPICIOUS_BUF_SIZE */ +#if SUSPICIOUS_BUF_SIZE > 0 + if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != 0 + && + TREE_INT_CST_LOW(TYPE_MAX_VALUE(TYPE_DOMAIN(type)))+1 + >= SUSPICIOUS_BUF_SIZE) + return TRUE; + + current_function_defines_short_string = TRUE; +#else + return TRUE; +#endif + } + + /* to protect every functions, sweep any arrays to the frame top */ + is_array = TRUE; + + return search_string_def(TREE_TYPE(type)); + + case UNION_TYPE: + case QUAL_UNION_TYPE: + case RECORD_TYPE: + /* Output the name, type, position (in bits), size (in bits) of each + field. */ + for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem)) + { + /* Omit here local type decls until we know how to support them. */ + if ((TREE_CODE (tem) == TYPE_DECL) + || (TREE_CODE (tem) == VAR_DECL && TREE_STATIC (tem))) + continue; + + if (search_string_def(TREE_TYPE(tem))) return TRUE; + } + break; + + case POINTER_TYPE: + case REFERENCE_TYPE: + /* I'm not sure whether OFFSET_TYPE needs this treatment, + so I'll play safe and return 1. */ + case OFFSET_TYPE: + default: + break; + } + + return FALSE; +} + +/* + * examine whether the input contains frame pointer addressing + */ +int +contains_fp (op) + rtx op; +{ + register enum rtx_code code; + rtx x; + int i, j; + const char *fmt; + + x = op; + if (x == 0) + return FALSE; + + code = GET_CODE (x); + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case REG: + case ADDRESSOF: + return FALSE; + + case PLUS: + if (XEXP (x, 0) == virtual_stack_vars_rtx + && CONSTANT_P (XEXP (x, 1))) + return TRUE; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + { + if (contains_fp (XEXP (x, i))) return TRUE; + } + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + if (contains_fp (XVECEXP (x, i, j))) return TRUE; + + return FALSE; +} + + +static int +search_pointer_def (type) + tree type; +{ + tree tem; + + if (! type) + return FALSE; + + switch (TREE_CODE (type)) + { + case UNION_TYPE: + case QUAL_UNION_TYPE: + case RECORD_TYPE: + /* Output the name, type, position (in bits), size (in bits) of each + field. */ + for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem)) + { + /* Omit here local type decls until we know how to support them. */ + if ((TREE_CODE (tem) == TYPE_DECL) + || (TREE_CODE (tem) == VAR_DECL && TREE_STATIC (tem))) + continue; + + if (search_pointer_def (TREE_TYPE(tem))) return TRUE; + } + break; + + case ARRAY_TYPE: + return search_pointer_def (TREE_TYPE(type)); + + case POINTER_TYPE: + case REFERENCE_TYPE: + case OFFSET_TYPE: + if (TYPE_READONLY (TREE_TYPE (type))) + { + /* unless this pointer contains function pointer, + it should be protected */ + return search_func_pointer (TREE_TYPE (type)); + } + return TRUE; + + default: + break; + } + + return FALSE; +} + + +static int +search_func_pointer (type) + tree type; +{ + tree tem; + + if (! type) + return FALSE; + + switch (TREE_CODE (type)) + { + case UNION_TYPE: + case QUAL_UNION_TYPE: + case RECORD_TYPE: + if (! TREE_VISITED (type)) + { + /* mark the type as having been visited already */ + TREE_VISITED (type) = 1; + + /* Output the name, type, position (in bits), size (in bits) of + each field. */ + for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem)) + { + if (TREE_CODE (tem) == FIELD_DECL + && search_func_pointer (TREE_TYPE(tem))) { + TREE_VISITED (type) = 0; + return TRUE; + } + } + + TREE_VISITED (type) = 0; + } + break; + + case ARRAY_TYPE: + return search_func_pointer (TREE_TYPE(type)); + + case POINTER_TYPE: + case REFERENCE_TYPE: + /* I'm not sure whether OFFSET_TYPE needs this treatment, + so I'll play safe and return 1. */ + case OFFSET_TYPE: + if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) + return TRUE; + return search_func_pointer (TREE_TYPE(type)); + + default: + break; + } + + return FALSE; +} + + +/* + * check whether the specified rtx contains PLUS rtx with used flag. + */ +static int +check_used_flag (x) + rtx x; +{ + register int i, j; + register enum rtx_code code; + register const char *format_ptr; + + if (x == 0) + return FALSE; + + code = GET_CODE (x); + + switch (code) + { + case REG: + case QUEUED: + case CONST_INT: + case CONST_DOUBLE: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + return FALSE; + + case PLUS: + if (x->used) + return TRUE; + + default: + break; + } + + format_ptr = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++) + { + switch (*format_ptr++) + { + case 'e': + if (check_used_flag (XEXP (x, i))) + return TRUE; + break; + + case 'E': + for (j = 0; j < XVECLEN (x, i); j++) + if (check_used_flag (XVECEXP (x, i, j))) + return TRUE; + break; + } + } + + return FALSE; +} + + +static void +reset_used_flags_for_insns (insn) + rtx insn; +{ + register int i, j; + register enum rtx_code code; + register const char *format_ptr; + + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + code = GET_CODE (insn); + insn->used = 0; + format_ptr = GET_RTX_FORMAT (code); + + for (i = 0; i < GET_RTX_LENGTH (code); i++) + { + switch (*format_ptr++) { + case 'e': + reset_used_flags_of_plus (XEXP (insn, i)); + break; + + case 'E': + for (j = 0; j < XVECLEN (insn, i); j++) + reset_used_flags_of_plus (XVECEXP (insn, i, j)); + break; + } + } + } +} + +static void +reset_used_flags_for_decls (block) + tree block; +{ + tree types; + rtx home; + + while (block && TREE_CODE(block)==BLOCK) + { + types = BLOCK_VARS(block); + + while (types) + { + /* skip the declaration that refers an external variable and + also skip an global variable */ + if (! DECL_EXTERNAL (types)) + { + if (!DECL_RTL_SET_P (types)) goto next; + home = DECL_RTL (types); + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == PLUS + && GET_CODE (XEXP (XEXP (home, 0), 1)) == CONST_INT) + { + XEXP (home, 0)->used = 0; + } + } + next: + types = TREE_CHAIN(types); + } + + reset_used_flags_for_decls (BLOCK_SUBBLOCKS (block)); + + block = BLOCK_CHAIN (block); + } +} + +/* Clear the USED bits only of type PLUS in X */ + +static void +reset_used_flags_of_plus (x) + rtx x; +{ + register int i, j; + register enum rtx_code code; + register const char *format_ptr; + + if (x == 0) + return; + + code = GET_CODE (x); + + /* These types may be freely shared so we needn't do any resetting + for them. */ + + switch (code) + { + case REG: + case QUEUED: + case CONST_INT: + case CONST_DOUBLE: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + return; + + case INSN: + case JUMP_INSN: + case CALL_INSN: + case NOTE: + case LABEL_REF: + case BARRIER: + /* The chain of insns is not being copied. */ + return; + + case PLUS: + x->used = 0; + break; + + case CALL_PLACEHOLDER: + reset_used_flags_for_insns (XEXP (x, 0)); + reset_used_flags_for_insns (XEXP (x, 1)); + reset_used_flags_for_insns (XEXP (x, 2)); + break; + + default: + break; + } + + format_ptr = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++) + { + switch (*format_ptr++) + { + case 'e': + reset_used_flags_of_plus (XEXP (x, i)); + break; + + case 'E': + for (j = 0; j < XVECLEN (x, i); j++) + reset_used_flags_of_plus (XVECEXP (x, i, j)); + break; + } + } +} + + +static void +rtl_prologue (insn) + rtx insn; +{ +#if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main) +#undef HAS_INIT_SECTION +#define HAS_INIT_SECTION +#endif + + rtx _val; + + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == NOTE + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) + break; + +#if !defined (HAS_INIT_SECTION) + /* If this function is `main', skip a call to `__main' + to run guard instruments after global initializers, etc. */ + if (DECL_NAME (current_function_decl) + && MAIN_NAME_P (DECL_NAME (current_function_decl)) + && DECL_CONTEXT (current_function_decl) == NULL_TREE) + { + rtx fbinsn = insn; + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == NOTE + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG) + break; + if (insn == 0) insn = fbinsn; + } +#endif + + /* mark the next insn of FUNCTION_BEG insn */ + prologue_insert_point = NEXT_INSN (insn); + + start_sequence (); + + _guard = gen_rtx_MEM (GUARD_m, gen_rtx_SYMBOL_REF (Pmode, "__guard")); + emit_move_insn ( guard_area, _guard); + + _val = get_insns (); + end_sequence (); + + emit_insn_before (_val, prologue_insert_point); +} + +static void +rtl_epilogue (insn) + rtx insn; +{ + rtx if_false_label; + rtx _val; + rtx funcname; + tree funcstr; + int flag_have_return = FALSE; + + start_sequence (); + +#ifdef HAVE_return + if (HAVE_return) + { + rtx insn; + return_label = gen_label_rtx (); + + for (insn = prologue_insert_point; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == JUMP_INSN + && GET_CODE (PATTERN (insn)) == RETURN + && GET_MODE (PATTERN (insn)) == VOIDmode) + { + rtx pat = gen_rtx_SET (VOIDmode, + pc_rtx, + gen_rtx_LABEL_REF (VOIDmode, + return_label)); + PATTERN (insn) = pat; + flag_have_return = TRUE; + } + + + emit_label (return_label); + } +#endif + + /* if (guard_area != _guard) */ + compare_from_rtx (guard_area, _guard, NE, 0, GUARD_m, NULL_RTX); + + if_false_label = gen_label_rtx (); /* { */ + emit_jump_insn ( gen_beq(if_false_label)); + + /* generate string for the current function name */ + funcstr = build_string (strlen(current_function_name)+1, + current_function_name); + TREE_TYPE (funcstr) = build_array_type (char_type_node, 0); + funcname = output_constant_def (funcstr, 1); + + emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__stack_smash_handler"), + 0, VOIDmode, 2, + XEXP (funcname, 0), Pmode, guard_area, GUARD_m); + + /* generate RTL to return from the current function */ + + emit_barrier (); /* } */ + emit_label (if_false_label); + + /* generate RTL to return from the current function */ + if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl))) + use_return_register (); + +#ifdef HAVE_return + if (HAVE_return && flag_have_return) + { + emit_jump_insn (gen_return ()); + emit_barrier (); + } +#endif + + _val = get_insns (); + end_sequence (); + + emit_insn_after (_val, insn); +} + + +static void +arrange_var_order (block) + tree block; +{ + tree types; + HOST_WIDE_INT offset; + + while (block && TREE_CODE(block)==BLOCK) + { + /* arrange the location of character arrays in depth first. */ + arrange_var_order (BLOCK_SUBBLOCKS (block)); + + types = BLOCK_VARS (block); + + while (types) + { + /* skip the declaration that refers an external variable */ + /* name: types.decl.assembler_name.id */ + if (! DECL_EXTERNAL (types) && ! TREE_STATIC (types) + && TREE_CODE (types) == VAR_DECL + && ! DECL_ARTIFICIAL (types) + && ! DECL_VAR_INLINE (types) /* don't sweep inlined string */ + && DECL_RTL_SET_P (types) + && GET_CODE (DECL_RTL (types)) == MEM + && GET_MODE (DECL_RTL (types)) == BLKmode + + && (is_array=0, search_string_def (TREE_TYPE (types)) + || (! current_function_defines_vulnerable_string + && is_array))) + { + rtx home = DECL_RTL (types); + + if (!(GET_CODE (home) == MEM + && (GET_CODE (XEXP (home, 0)) == MEM + || + (GET_CODE (XEXP (home, 0)) == REG + && XEXP (home, 0) != virtual_stack_vars_rtx + && REGNO (XEXP (home, 0)) != HARD_FRAME_POINTER_REGNUM + && REGNO (XEXP (home, 0)) != STACK_POINTER_REGNUM +#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM + && REGNO (XEXP (home, 0)) != ARG_POINTER_REGNUM +#endif + )))) + { + /* found a string variable */ + HOST_WIDE_INT var_size = + ((TREE_INT_CST_LOW (DECL_SIZE (types)) + BITS_PER_UNIT - 1) + / BITS_PER_UNIT); + + /* confirmed it is BLKmode. */ + int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT; + var_size = CEIL_ROUND (var_size, alignment); + + /* skip the variable if it is top of the region + specified by sweep_frame_offset */ + offset = AUTO_OFFSET (XEXP (DECL_RTL (types), 0)); + if (offset == sweep_frame_offset - var_size) + sweep_frame_offset -= var_size; + + else if (offset < sweep_frame_offset - var_size) + sweep_string_variable (DECL_RTL (types), var_size); + } + } + + types = TREE_CHAIN(types); + } + + block = BLOCK_CHAIN (block); + } +} + + +static void +copy_args_for_protection () +{ + tree parms = DECL_ARGUMENTS (current_function_decl); + rtx temp_rtx; + + parms = DECL_ARGUMENTS (current_function_decl); + for (; parms; parms = TREE_CHAIN (parms)) + if (DECL_NAME (parms) && TREE_TYPE (parms) != error_mark_node) + { + if (PARM_PASSED_IN_MEMORY (parms) && DECL_NAME (parms)) + { + int string_p; + + /* + skip arguemnt protection if the last argument is used + for the variable argument + */ + /* + tree fntype; + if (TREE_CHAIN (parms) == 0) + { + fntype = TREE_TYPE (current_function_decl); + + if ((TYPE_ARG_TYPES (fntype) != 0 + && TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype))) + != void_type_node) + || current_function_varargs) + continue; + } + */ + + string_p = search_string_def (TREE_TYPE(parms)); + + /* check if it is a candidate to move */ + if (string_p || search_pointer_def (TREE_TYPE (parms))) + { + int arg_size + = ((TREE_INT_CST_LOW (DECL_SIZE (parms)) + BITS_PER_UNIT - 1) + / BITS_PER_UNIT); + tree passed_type = DECL_ARG_TYPE (parms); + tree nominal_type = TREE_TYPE (parms); + + start_sequence (); + + if (GET_CODE (DECL_RTL (parms)) == REG) + { + rtx safe = 0; + + change_arg_use_of_insns (prologue_insert_point, + DECL_RTL (parms), &safe, 0); + if (safe) + { + /* generate codes for copying the content */ + rtx movinsn = emit_move_insn (safe, DECL_RTL (parms)); + + /* avoid register elimination in gcse.c (COPY-PROP)*/ + PATTERN (movinsn)->volatil = 1; + + /* save debugger info */ + DECL_INCOMING_RTL (parms) = safe; + } + } + else if (GET_CODE (DECL_RTL (parms)) == MEM + && GET_CODE (XEXP (DECL_RTL (parms), 0)) == ADDRESSOF) + { + rtx movinsn; + rtx safe = gen_reg_rtx (GET_MODE (DECL_RTL (parms))); + + /* generate codes for copying the content */ + movinsn = emit_move_insn (safe, DECL_INCOMING_RTL (parms)); + /* avoid register elimination in gcse.c (COPY-PROP)*/ + PATTERN (movinsn)->volatil = 1; + + /* change the addressof information to the newly + allocated pseudo register */ + emit_move_insn (DECL_RTL (parms), safe); + + /* save debugger info */ + DECL_INCOMING_RTL (parms) = safe; + } + + /* See if the frontend wants to pass this by invisible + reference. */ + else if (passed_type != nominal_type + && POINTER_TYPE_P (passed_type) + && TREE_TYPE (passed_type) == nominal_type) + { + rtx safe = 0, orig = XEXP (DECL_RTL (parms), 0); + + change_arg_use_of_insns (prologue_insert_point, + orig, &safe, 0); + if (safe) + { + /* generate codes for copying the content */ + rtx movinsn = emit_move_insn (safe, orig); + + /* avoid register elimination in gcse.c (COPY-PROP)*/ + PATTERN (movinsn)->volatil = 1; + + /* save debugger info */ + DECL_INCOMING_RTL (parms) = safe; + } + } + + else + { + /* declare temporary local variable DECL_NAME (parms) */ + temp_rtx + = assign_stack_local (DECL_MODE (parms), arg_size, + DECL_MODE (parms) == BLKmode ? + -1 : 0); + + MEM_IN_STRUCT_P (temp_rtx) + = AGGREGATE_TYPE_P (TREE_TYPE (parms)); + set_mem_alias_set (temp_rtx, get_alias_set (parms)); + + /* move_arg_location may change the contents of + DECL_RTL (parms). to avoid this, copies the contents */ + /* SET_DECL_RTL (parms, copy_rtx (DECL_RTL (parms))); */ + + /* generate codes for copying the content */ + store_expr (parms, temp_rtx, 0); + + /* change the reference for each instructions */ + move_arg_location (prologue_insert_point, DECL_RTL (parms), + temp_rtx, arg_size); + + /* change the location of parms variable */ + SET_DECL_RTL (parms, temp_rtx); + + /* change debugger info */ + DECL_INCOMING_RTL (parms) = temp_rtx; + } + + emit_insn_before (get_insns (), prologue_insert_point); + end_sequence (); + +#ifdef FRAME_GROWS_DOWNWARD + /* process the string argument */ + if (string_p && DECL_MODE (parms) == BLKmode) + { + int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT; + arg_size = CEIL_ROUND (arg_size, alignment); + + /* change the reference for each instructions */ + sweep_string_variable (DECL_RTL (parms), arg_size); + } +#endif + } + } + } +} + + +/* + sweep a string variable to the local variable addressed + by sweep_frame_offset, that is a last position of string variables. +*/ +static void +sweep_string_variable (sweep_var, var_size) + rtx sweep_var; + HOST_WIDE_INT var_size; +{ + HOST_WIDE_INT sweep_offset; + + switch (GET_CODE (sweep_var)) + { + case MEM: + if (GET_CODE (XEXP (sweep_var, 0)) == ADDRESSOF + && GET_CODE (XEXP (XEXP (sweep_var, 0), 0)) == REG) + return; + sweep_offset = AUTO_OFFSET(XEXP (sweep_var, 0)); + break; + case CONST_INT: + sweep_offset = INTVAL (sweep_var); + break; + default: + abort (); + } + + /* scan all declarations of variables and fix the offset address of + the variable based on the frame pointer */ + sweep_string_in_decls (DECL_INITIAL (current_function_decl), + sweep_offset, var_size); + + /* scan all argument variable and fix the offset address based on + the frame pointer */ + sweep_string_in_args (DECL_ARGUMENTS (current_function_decl), + sweep_offset, var_size); + + /* For making room for sweep variable, scan all insns and + fix the offset address of the variable that is based on frame pointer */ + sweep_string_use_of_insns (function_first_insn, sweep_offset, var_size); + + + /* Clear all the USED bits in operands of all insns and declarations of + local vars */ + reset_used_flags_for_decls (DECL_INITIAL (current_function_decl)); + reset_used_flags_for_insns (function_first_insn); + + sweep_frame_offset -= var_size; +} + + + +/* + move an argument to the local variable addressed by frame_offset +*/ +static void +move_arg_location (insn, orig, new, var_size) + rtx insn, orig, new; + HOST_WIDE_INT var_size; +{ + /* For making room for sweep variable, scan all insns and + fix the offset address of the variable that is based on frame pointer */ + change_arg_use_of_insns (insn, orig, &new, var_size); + + + /* Clear all the USED bits in operands of all insns and declarations + of local vars */ + reset_used_flags_for_insns (insn); +} + + +static void +sweep_string_in_decls (block, sweep_offset, sweep_size) + tree block; + HOST_WIDE_INT sweep_offset, sweep_size; +{ + tree types; + HOST_WIDE_INT offset; + rtx home; + + while (block && TREE_CODE(block)==BLOCK) + { + types = BLOCK_VARS(block); + + while (types) + { + /* skip the declaration that refers an external variable and + also skip an global variable */ + if (! DECL_EXTERNAL (types) && ! TREE_STATIC (types)) { + + if (!DECL_RTL_SET_P (types)) goto next; + home = DECL_RTL (types); + + /* process for static local variable */ + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == SYMBOL_REF) + goto next; + + if (GET_CODE (home) == MEM + && XEXP (home, 0) == virtual_stack_vars_rtx) + { + offset = 0; + + /* the operand related to the sweep variable */ + if (sweep_offset <= offset + && offset < sweep_offset + sweep_size) + { + offset = sweep_frame_offset - sweep_size - sweep_offset; + + XEXP (home, 0) = plus_constant (virtual_stack_vars_rtx, + offset); + XEXP (home, 0)->used = 1; + } + else if (sweep_offset <= offset + && offset < sweep_frame_offset) + { + /* the rest of variables under sweep_frame_offset, + shift the location */ + XEXP (home, 0) = plus_constant (virtual_stack_vars_rtx, + -sweep_size); + XEXP (home, 0)->used = 1; + } + } + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == MEM) + { + /* process for dynamically allocated aray */ + home = XEXP (home, 0); + } + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == PLUS + && XEXP (XEXP (home, 0), 0) == virtual_stack_vars_rtx + && GET_CODE (XEXP (XEXP (home, 0), 1)) == CONST_INT) + { + if (! XEXP (home, 0)->used) + { + offset = AUTO_OFFSET(XEXP (home, 0)); + + /* the operand related to the sweep variable */ + if (sweep_offset <= offset + && offset < sweep_offset + sweep_size) + { + + offset + += sweep_frame_offset - sweep_size - sweep_offset; + XEXP (XEXP (home, 0), 1) = gen_rtx_CONST_INT (VOIDmode, + offset); + + /* mark */ + XEXP (home, 0)->used = 1; + } + else if (sweep_offset <= offset + && offset < sweep_frame_offset) + { /* the rest of variables under sweep_frame_offset, + so shift the location */ + + XEXP (XEXP (home, 0), 1) + = gen_rtx_CONST_INT (VOIDmode, offset - sweep_size); + + /* mark */ + XEXP (home, 0)->used = 1; + } + } + } + + } + next: + types = TREE_CHAIN(types); + } + + sweep_string_in_decls (BLOCK_SUBBLOCKS (block), + sweep_offset, sweep_size); + block = BLOCK_CHAIN (block); + } +} + + +static void +sweep_string_in_args (parms, sweep_offset, sweep_size) + tree parms; + HOST_WIDE_INT sweep_offset, sweep_size; +{ + rtx home; + HOST_WIDE_INT offset; + + for (; parms; parms = TREE_CHAIN (parms)) + if (DECL_NAME (parms) && TREE_TYPE (parms) != error_mark_node) + { + if (PARM_PASSED_IN_MEMORY (parms) && DECL_NAME (parms)) + { + home = DECL_INCOMING_RTL (parms); + + if (XEXP (home, 0)->used) continue; + + offset = AUTO_OFFSET(XEXP (home, 0)); + + /* the operand related to the sweep variable */ + if (AUTO_BASEPTR (XEXP (home, 0)) == virtual_stack_vars_rtx) + { + if (sweep_offset <= offset + && offset < sweep_offset + sweep_size) + { + offset += sweep_frame_offset - sweep_size - sweep_offset; + XEXP (XEXP (home, 0), 1) = gen_rtx_CONST_INT (VOIDmode, + offset); + + /* mark */ + XEXP (home, 0)->used = 1; + } + else if (sweep_offset <= offset + && offset < sweep_frame_offset) + { + /* the rest of variables under sweep_frame_offset, + shift the location */ + XEXP (XEXP (home, 0), 1) + = gen_rtx_CONST_INT (VOIDmode, offset - sweep_size); + + /* mark */ + XEXP (home, 0)->used = 1; + } + } + } + } +} + + +static int has_virtual_reg; + +static void +sweep_string_use_of_insns (insn, sweep_offset, sweep_size) + rtx insn; + HOST_WIDE_INT sweep_offset, sweep_size; +{ + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + has_virtual_reg = FALSE; + sweep_string_in_operand (insn, &PATTERN (insn), + sweep_offset, sweep_size); + sweep_string_in_operand (insn, ®_NOTES (insn), + sweep_offset, sweep_size); + } +} + + +static void +sweep_string_in_operand (insn, loc, sweep_offset, sweep_size) + rtx insn, *loc; + HOST_WIDE_INT sweep_offset, sweep_size; +{ + register rtx x = *loc; + register enum rtx_code code; + int i, j, k = 0; + HOST_WIDE_INT offset; + const char *fmt; + + if (x == 0) + return; + + code = GET_CODE (x); + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + case ADDRESSOF: + return; + + case REG: + if (x == virtual_incoming_args_rtx + || x == virtual_stack_vars_rtx + || x == virtual_stack_dynamic_rtx + || x == virtual_outgoing_args_rtx + || x == virtual_cfa_rtx) + has_virtual_reg = TRUE; + return; + + case SET: + /* + skip setjmp setup insn and setjmp restore insn + Example: + (set (MEM (reg:SI xx)) (virtual_stack_vars_rtx))) + (set (virtual_stack_vars_rtx) (REG)) + */ + if (GET_CODE (XEXP (x, 0)) == MEM + && XEXP (x, 1) == virtual_stack_vars_rtx) + return; + if (XEXP (x, 0) == virtual_stack_vars_rtx + && GET_CODE (XEXP (x, 1)) == REG) + return; + break; + + case PLUS: + /* Handle typical case of frame register plus constant. */ + if (XEXP (x, 0) == virtual_stack_vars_rtx + && CONSTANT_P (XEXP (x, 1))) + { + if (x->used) goto single_use_of_virtual_reg; + + offset = AUTO_OFFSET(x); + if (RTX_INTEGRATED_P (x)) k = -1; /* for inline base ptr */ + + /* the operand related to the sweep variable */ + if (sweep_offset <= offset + k + && offset + k < sweep_offset + sweep_size) + { + offset += sweep_frame_offset - sweep_size - sweep_offset; + + XEXP (x, 0) = virtual_stack_vars_rtx; + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset); + x->used = 1; + } + else if (sweep_offset <= offset + k + && offset + k < sweep_frame_offset) + { + /* the rest of variables under sweep_frame_offset, + shift the location */ + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset - sweep_size); + x->used = 1; + } + + single_use_of_virtual_reg: + if (has_virtual_reg) { + /* excerpt from insn_invalid_p in recog.c */ + int icode = recog_memoized (insn); + + if (icode < 0 && asm_noperands (PATTERN (insn)) < 0) + { + rtx temp, seq; + + start_sequence (); + temp = force_operand (x, NULL_RTX); + seq = get_insns (); + end_sequence (); + + emit_insn_before (seq, insn); + if (! validate_change (insn, loc, temp, 0) + && ! validate_replace_rtx (x, temp, insn)) + fatal_insn ("sweep_string_in_operand", insn); + } + } + + has_virtual_reg = TRUE; + return; + } + +#ifdef FRAME_GROWS_DOWNWARD + /* + alert the case of frame register plus constant given by reg. + */ + else if (XEXP (x, 0) == virtual_stack_vars_rtx + && GET_CODE (XEXP (x, 1)) == REG) + fatal_insn ("sweep_string_in_operand: unknown addressing", insn); +#endif + + /* + process further subtree: + Example: (plus:SI (mem/s:SI (plus:SI (reg:SI 17) (const_int 8))) + (const_int 5)) + */ + break; + + case CALL_PLACEHOLDER: + for (i = 0; i < 3; i++) + { + rtx seq = XEXP (x, i); + if (seq) + { + push_to_sequence (seq); + sweep_string_use_of_insns (XEXP (x, i), + sweep_offset, sweep_size); + XEXP (x, i) = get_insns (); + end_sequence (); + } + } + break; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + { + /* + virtual_stack_vars_rtx without offset + Example: + (set (reg:SI xx) (reg:SI 78)) + (set (reg:SI xx) (MEM (reg:SI 78))) + */ + if (XEXP (x, i) == virtual_stack_vars_rtx) + fatal_insn ("sweep_string_in_operand: unknown fp usage", insn); + sweep_string_in_operand (insn, &XEXP (x, i), sweep_offset, sweep_size); + } + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + sweep_string_in_operand (insn, &XVECEXP (x, i, j), sweep_offset, sweep_size); +} + + +/* + change a argument variable to the local variable addressed + by the "new" variable. +*/ +static void +change_arg_use_of_insns (insn, orig, new, size) + rtx insn, orig, *new; + HOST_WIDE_INT size; +{ + change_arg_use_of_insns_2 (insn, orig, new, size); +} + +static void +change_arg_use_of_insns_2 (insn, orig, new, size) + rtx insn, orig, *new; + HOST_WIDE_INT size; +{ + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + rtx seq; + + start_sequence (); + change_arg_use_in_operand (insn, PATTERN (insn), orig, new, size); + + seq = get_insns (); + end_sequence (); + emit_insn_before (seq, insn); + + /* load_multiple insn from virtual_incoming_args_rtx have several + load insns. If every insn change the load address of arg + to frame region, those insns are moved before the PARALLEL insn + and remove the PARALLEL insn. */ + if (GET_CODE (PATTERN (insn)) == PARALLEL + && XVECLEN (PATTERN (insn), 0) == 0) + delete_insn (insn); + } +} + + + +static void +change_arg_use_in_operand (insn, x, orig, new, size) + rtx insn, x, orig, *new; + HOST_WIDE_INT size; +{ + register enum rtx_code code; + int i, j; + HOST_WIDE_INT offset; + const char *fmt; + + if (x == 0) + return; + + code = GET_CODE (x); + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + case REG: + case ADDRESSOF: + return; + + case MEM: + /* Handle special case of MEM (incoming_args) */ + if (GET_CODE (orig) == MEM + && XEXP (x, 0) == virtual_incoming_args_rtx) + { + offset = 0; + + /* the operand related to the sweep variable */ + if (AUTO_OFFSET(XEXP (orig, 0)) <= offset && + offset < AUTO_OFFSET(XEXP (orig, 0)) + size) { + + offset = AUTO_OFFSET(XEXP (*new, 0)) + + (offset - AUTO_OFFSET(XEXP (orig, 0))); + + XEXP (x, 0) = plus_constant (virtual_stack_vars_rtx, offset); + XEXP (x, 0)->used = 1; + + return; + } + } + break; + + case PLUS: + /* Handle special case of frame register plus constant. */ + if (GET_CODE (orig) == MEM + && XEXP (x, 0) == virtual_incoming_args_rtx + && CONSTANT_P (XEXP (x, 1)) + && ! x->used) + { + offset = AUTO_OFFSET(x); + + /* the operand related to the sweep variable */ + if (AUTO_OFFSET(XEXP (orig, 0)) <= offset && + offset < AUTO_OFFSET(XEXP (orig, 0)) + size) { + + offset = AUTO_OFFSET(XEXP (*new, 0)) + + (offset - AUTO_OFFSET(XEXP (orig, 0))); + + XEXP (x, 0) = virtual_stack_vars_rtx; + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset); + x->used = 1; + + return; + } + + /* + process further subtree: + Example: (plus:SI (mem/s:SI (plus:SI (reg:SI 17) (const_int 8))) + (const_int 5)) + */ + } + break; + + case SET: + /* Handle special case of "set (REG or MEM) (incoming_args)". + It means that the the address of the 1st argument is stored. */ + if (GET_CODE (orig) == MEM + && XEXP (x, 1) == virtual_incoming_args_rtx) + { + offset = 0; + + /* the operand related to the sweep variable */ + if (AUTO_OFFSET(XEXP (orig, 0)) <= offset && + offset < AUTO_OFFSET(XEXP (orig, 0)) + size) { + + offset = AUTO_OFFSET(XEXP (*new, 0)) + + (offset - AUTO_OFFSET(XEXP (orig, 0))); + + XEXP (x, 1) = force_operand (plus_constant (virtual_stack_vars_rtx, + offset), NULL_RTX); + XEXP (x, 1)->used = 1; + + return; + } + } + break; + + case CALL_PLACEHOLDER: + for (i = 0; i < 3; i++) + { + rtx seq = XEXP (x, i); + if (seq) + { + push_to_sequence (seq); + change_arg_use_of_insns_2 (XEXP (x, i), orig, new, size); + XEXP (x, i) = get_insns (); + end_sequence (); + } + } + break; + + case PARALLEL: + for (j = 0; j < XVECLEN (x, 0); j++) + { + change_arg_use_in_operand (insn, XVECEXP (x, 0, j), orig, new, size); + } + if (recog_memoized (insn) < 0) + { + for (i = 0, j = 0; j < XVECLEN (x, 0); j++) + { + /* if parallel insn has a insn used virtual_incoming_args_rtx, + the insn is removed from this PARALLEL insn. */ + if (check_used_flag (XVECEXP (x, 0, j))) + { + emit_insn (XVECEXP (x, 0, j)); + XVECEXP (x, 0, j) = NULL; + } + else + XVECEXP (x, 0, i++) = XVECEXP (x, 0, j); + } + PUT_NUM_ELEM (XVEC (x, 0), i); + } + return; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + { + if (XEXP (x, i) == orig) + { + if (*new == 0) *new = gen_reg_rtx (GET_MODE (orig)); + XEXP (x, i) = *new; + continue; + } + change_arg_use_in_operand (insn, XEXP (x, i), orig, new, size); + } + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + { + + if (XVECEXP (x, i, j) == orig) + { + if (*new == 0) *new = gen_reg_rtx (GET_MODE (orig)); + XVECEXP (x, i, j) = *new; + continue; + } + change_arg_use_in_operand (insn, XVECEXP (x, i, j), orig, new, size); + } +} + + +static void +validate_insns_of_varrefs (insn) + rtx insn; +{ + rtx next; + + /* Initialize recognition, indicating that volatile is OK. */ + init_recog (); + + for (; insn; insn = next) + { + next = NEXT_INSN (insn); + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + /* excerpt from insn_invalid_p in recog.c */ + int icode = recog_memoized (insn); + + if (icode < 0 && asm_noperands (PATTERN (insn)) < 0) + validate_operand_of_varrefs (insn, &PATTERN (insn)); + } + } + + init_recog_no_volatile (); +} + + +static void +validate_operand_of_varrefs (insn, loc) + rtx insn, *loc; +{ + register enum rtx_code code; + rtx x, temp, seq; + int i, j; + const char *fmt; + + x = *loc; + if (x == 0) + return; + + code = GET_CODE (x); + + switch (code) + { + case USE: + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + case REG: + case ADDRESSOF: + return; + + case PLUS: + /* validate insn of frame register plus constant. */ + if (GET_CODE (x) == PLUS + && XEXP (x, 0) == virtual_stack_vars_rtx + && CONSTANT_P (XEXP (x, 1))) + { + start_sequence (); + + { /* excerpt from expand_binop in optabs.c */ + optab binoptab = add_optab; + enum machine_mode mode = GET_MODE (x); + int icode = (int) binoptab->handlers[(int) mode].insn_code; + enum machine_mode mode1 = insn_data[icode].operand[2].mode; + rtx pat; + rtx xop0 = XEXP (x, 0), xop1 = XEXP (x, 1); + temp = gen_reg_rtx (mode); + + /* Now, if insn's predicates don't allow offset operands, + put them into pseudo regs. */ + + if (! (*insn_data[icode].operand[2].predicate) (xop1, mode1) + && mode1 != VOIDmode) + xop1 = copy_to_mode_reg (mode1, xop1); + + pat = GEN_FCN (icode) (temp, xop0, xop1); + if (pat) + emit_insn (pat); + } + seq = get_insns (); + end_sequence (); + + emit_insn_before (seq, insn); + if (! validate_change (insn, loc, temp, 0)) + abort (); + return; + } + break; + + + case CALL_PLACEHOLDER: + for (i = 0; i < 3; i++) + { + rtx seq = XEXP (x, i); + if (seq) + { + push_to_sequence (seq); + validate_insns_of_varrefs (XEXP (x, i)); + XEXP (x, i) = get_insns (); + end_sequence (); + } + } + break; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + validate_operand_of_varrefs (insn, &XEXP (x, i)); + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + validate_operand_of_varrefs (insn, &XVECEXP (x, i, j)); +} + + + +/* Return size that is not allocated for stack frame. It will be allocated + to modify the home of pseudo registers called from global_alloc. */ + +HOST_WIDE_INT +get_frame_free_size () +{ + if (! flag_propolice_protection) + return 0; + + return push_allocated_offset - push_frame_offset; +} + + +/* + The following codes are invoked after the instantiation of pseuso registers. + + Reorder local variables to place a peudo register after buffers to avoid + the corruption of local variables that could be used to further corrupt + arbitrary memory locations. +*/ +#if !defined(FRAME_GROWS_DOWNWARD) && defined(STACK_GROWS_DOWNWARD) +static void push_frame + PARAMS ((HOST_WIDE_INT var_size, HOST_WIDE_INT boundary)); +static void push_frame_in_decls + PARAMS ((tree block, HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void push_frame_in_args + PARAMS ((tree parms, HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void push_frame_of_insns + PARAMS ((rtx insn, HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void push_frame_in_operand + PARAMS ((rtx insn, rtx orig, + HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void push_frame_of_reg_equiv_memory_loc + PARAMS ((HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void push_frame_of_reg_equiv_constant + PARAMS ((HOST_WIDE_INT push_size, HOST_WIDE_INT boundary)); +static void reset_used_flags_for_push_frame PARAMS ((void)); +static int check_out_of_frame_access + PARAMS ((rtx insn, HOST_WIDE_INT boundary)); +static int check_out_of_frame_access_in_operand + PARAMS ((rtx, HOST_WIDE_INT boundary)); +#endif + +rtx +assign_stack_local_for_pseudo_reg (mode, size, align) + enum machine_mode mode; + HOST_WIDE_INT size; + int align; +{ +#if defined(FRAME_GROWS_DOWNWARD) || !defined(STACK_GROWS_DOWNWARD) + return assign_stack_local (mode, size, align); +#else + tree blocks = DECL_INITIAL (current_function_decl); + rtx new; + HOST_WIDE_INT saved_frame_offset, units_per_push, starting_frame; + int first_call_from_purge_addressof, first_call_from_global_alloc; + + if (! flag_propolice_protection + || size == 0 + || ! blocks + || current_function_is_inlinable + || ! search_string_from_argsandvars (1) + || current_function_contains_functions) + return assign_stack_local (mode, size, align); + + first_call_from_purge_addressof = !push_frame_offset && !cse_not_expected; + first_call_from_global_alloc = !saved_cse_not_expected && cse_not_expected; + saved_cse_not_expected = cse_not_expected; + + starting_frame = (STARTING_FRAME_OFFSET)? + STARTING_FRAME_OFFSET:BIGGEST_ALIGNMENT / BITS_PER_UNIT; + units_per_push = MAX(BIGGEST_ALIGNMENT / BITS_PER_UNIT, + GET_MODE_SIZE (mode)); + + if (first_call_from_purge_addressof) + { + push_frame_offset = push_allocated_offset; + if (check_out_of_frame_access (get_insns (), starting_frame)) + { + /* if there is an access beyond frame, push dummy region to seperate + the address of instantiated variables */ + push_frame (GET_MODE_SIZE (DImode), 0); + assign_stack_local (BLKmode, GET_MODE_SIZE (DImode), -1); + } + } + + if (first_call_from_global_alloc) + { + push_frame_offset = push_allocated_offset = 0; + if (check_out_of_frame_access (get_insns (), starting_frame)) + { + if (STARTING_FRAME_OFFSET) + { + /* if there is an access beyond frame, push dummy region + to seperate the address of instantiated variables */ + push_frame (GET_MODE_SIZE (DImode), 0); + assign_stack_local (BLKmode, GET_MODE_SIZE (DImode), -1); + } + else + push_allocated_offset = starting_frame; + } + } + + saved_frame_offset = frame_offset; + frame_offset = push_frame_offset; + + new = assign_stack_local (mode, size, align); + + push_frame_offset = frame_offset; + frame_offset = saved_frame_offset; + + if (push_frame_offset > push_allocated_offset) + { + push_frame (units_per_push, + push_allocated_offset + STARTING_FRAME_OFFSET); + + assign_stack_local (BLKmode, units_per_push, -1); + push_allocated_offset += units_per_push; + } + + /* At the second call from global alloc, alpha push frame and assign + a local variable to the top of the stack */ + if (first_call_from_global_alloc && STARTING_FRAME_OFFSET == 0) + push_frame_offset = push_allocated_offset = 0; + + return new; +#endif +} + + +#if !defined(FRAME_GROWS_DOWNWARD) && defined(STACK_GROWS_DOWNWARD) +/* + push frame infomation for instantiating pseudo register at the top of stack. + This is only for the "frame grows upward", it means FRAME_GROWS_DOWNWARD is + not defined. + + It is called by purge_addressof function and global_alloc (or reload) + function. +*/ +static void +push_frame (var_size, boundary) + HOST_WIDE_INT var_size, boundary; +{ + reset_used_flags_for_push_frame(); + + /* scan all declarations of variables and fix the offset address of + the variable based on the frame pointer */ + push_frame_in_decls (DECL_INITIAL (current_function_decl), + var_size, boundary); + + /* scan all argument variable and fix the offset address based on + the frame pointer */ + push_frame_in_args (DECL_ARGUMENTS (current_function_decl), + var_size, boundary); + + /* scan all operands of all insns and fix the offset address + based on the frame pointer */ + push_frame_of_insns (get_insns (), var_size, boundary); + + /* scan all reg_equiv_memory_loc and reg_equiv_constant*/ + push_frame_of_reg_equiv_memory_loc (var_size, boundary); + push_frame_of_reg_equiv_constant (var_size, boundary); + + reset_used_flags_for_push_frame(); +} + +static void +reset_used_flags_for_push_frame() +{ + int i; + extern rtx *reg_equiv_memory_loc; + extern rtx *reg_equiv_constant; + + /* Clear all the USED bits in operands of all insns and declarations of + local vars */ + reset_used_flags_for_decls (DECL_INITIAL (current_function_decl)); + reset_used_flags_for_insns (get_insns ()); + + + /* The following codes are processed if the push_frame is called from + global_alloc (or reload) function */ + if (reg_equiv_memory_loc == 0) return; + + for (i=LAST_VIRTUAL_REGISTER+1; i < max_regno; i++) + if (reg_equiv_memory_loc[i]) + { + rtx x = reg_equiv_memory_loc[i]; + + if (GET_CODE (x) == MEM + && GET_CODE (XEXP (x, 0)) == PLUS + && AUTO_BASEPTR (XEXP (x, 0)) == frame_pointer_rtx) + { + /* reset */ + XEXP (x, 0)->used = 0; + } + } + + + if (reg_equiv_constant == 0) return; + + for (i=LAST_VIRTUAL_REGISTER+1; i < max_regno; i++) + if (reg_equiv_constant[i]) + { + rtx x = reg_equiv_constant[i]; + + if (GET_CODE (x) == PLUS + && AUTO_BASEPTR (x) == frame_pointer_rtx) + { + /* reset */ + x->used = 0; + } + } +} + +static void +push_frame_in_decls (block, push_size, boundary) + tree block; + HOST_WIDE_INT push_size, boundary; +{ + tree types; + HOST_WIDE_INT offset; + rtx home; + + while (block && TREE_CODE(block)==BLOCK) + { + types = BLOCK_VARS(block); + + while (types) + { + /* skip the declaration that refers an external variable and + also skip an global variable */ + if (! DECL_EXTERNAL (types) && ! TREE_STATIC (types)) + { + + if (!DECL_RTL_SET_P (types)) goto next; + home = DECL_RTL (types); + + /* process for static local variable */ + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == SYMBOL_REF) + goto next; + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == REG) + { + if (XEXP (home, 0) != frame_pointer_rtx + || boundary != 0) + goto next; + + XEXP (home, 0) = plus_constant (frame_pointer_rtx, + push_size); + + /* mark */ + XEXP (home, 0)->used = 1; + } + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == MEM) + { + + /* process for dynamically allocated aray */ + home = XEXP (home, 0); + } + + if (GET_CODE (home) == MEM + && GET_CODE (XEXP (home, 0)) == PLUS + && GET_CODE (XEXP (XEXP (home, 0), 1)) == CONST_INT) + { + offset = AUTO_OFFSET(XEXP (home, 0)); + + if (! XEXP (home, 0)->used + && offset >= boundary) + { + offset += push_size; + XEXP (XEXP (home, 0), 1) + = gen_rtx_CONST_INT (VOIDmode, offset); + + /* mark */ + XEXP (home, 0)->used = 1; + } + } + + } + next: + types = TREE_CHAIN(types); + } + + push_frame_in_decls (BLOCK_SUBBLOCKS (block), push_size, boundary); + block = BLOCK_CHAIN (block); + } +} + + +static void +push_frame_in_args (parms, push_size, boundary) + tree parms; + HOST_WIDE_INT push_size, boundary; +{ + rtx home; + HOST_WIDE_INT offset; + + for (; parms; parms = TREE_CHAIN (parms)) + if (DECL_NAME (parms) && TREE_TYPE (parms) != error_mark_node) + { + if (PARM_PASSED_IN_MEMORY (parms) && DECL_NAME (parms)) + { + home = DECL_INCOMING_RTL (parms); + offset = AUTO_OFFSET(XEXP (home, 0)); + + if (XEXP (home, 0)->used || offset < boundary) continue; + + /* the operand related to the sweep variable */ + if (AUTO_BASEPTR (XEXP (home, 0)) == frame_pointer_rtx) + { + if (XEXP (home, 0) == frame_pointer_rtx) + XEXP (home, 0) = plus_constant (frame_pointer_rtx, + push_size); + else { + offset += push_size; + XEXP (XEXP (home, 0), 1) = gen_rtx_CONST_INT (VOIDmode, + offset); + } + + /* mark */ + XEXP (home, 0)->used = 1; + } + } + } +} + + +static int insn_pushed; +static int *fp_equiv = 0; + +static void +push_frame_of_insns (insn, push_size, boundary) + rtx insn; + HOST_WIDE_INT push_size, boundary; +{ + /* init fp_equiv */ + fp_equiv = (int *) xcalloc (max_reg_num (), sizeof (int)); + + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + rtx last; + + insn_pushed = FALSE; + + /* push frame in INSN operation */ + push_frame_in_operand (insn, PATTERN (insn), push_size, boundary); + + /* push frame in NOTE */ + push_frame_in_operand (insn, REG_NOTES (insn), push_size, boundary); + + /* push frame in CALL EXPR_LIST */ + if (GET_CODE (insn) == CALL_INSN) + push_frame_in_operand (insn, CALL_INSN_FUNCTION_USAGE (insn), + push_size, boundary); + + if (insn_pushed + && (last = try_split (PATTERN (insn), insn, 1)) != insn) + { + rtx first = NEXT_INSN (insn); + rtx trial = NEXT_INSN (first); + rtx pattern = PATTERN (trial); + rtx set; + + /* update REG_EQUIV info to the first splitted insn */ + if ((set = single_set (insn)) + && find_reg_note (insn, REG_EQUIV, SET_SRC (set)) + && GET_CODE (PATTERN (first)) == SET) + { + REG_NOTES (first) + = gen_rtx_EXPR_LIST (REG_EQUIV, + SET_SRC (PATTERN (first)), + REG_NOTES (first)); + } + + /* copy the first insn of splitted insns to the original insn and + delete the first insn, + because the original insn is pointed from records: + insn_chain, reg_equiv_init, used for global_alloc. */ + if (cse_not_expected) + { + add_insn_before (insn, first); + + /* Copy the various flags, and other information. */ + memcpy (insn, first, sizeof (struct rtx_def) - sizeof (rtunion)); + PATTERN (insn) = PATTERN (first); + INSN_CODE (insn) = INSN_CODE (first); + LOG_LINKS (insn) = LOG_LINKS (first); + REG_NOTES (insn) = REG_NOTES (first); + + /* then remove the first insn of splitted insns. */ + remove_insn (first); + INSN_DELETED_P (first) = 1; + } + + if (GET_CODE (pattern) == SET + && GET_CODE (XEXP (pattern, 0)) == REG + && GET_CODE (XEXP (pattern, 1)) == PLUS + && XEXP (pattern, 0) == XEXP (XEXP (pattern, 1), 0) + && CONSTANT_P (XEXP (XEXP (pattern, 1), 1))) + { + rtx offset = XEXP (XEXP (pattern, 1), 1); + fp_equiv[REGNO (XEXP (pattern, 0))] = INTVAL (offset); + + delete_insn (trial); + } + + insn = last; + } + } + + /* Clean up. */ + free (fp_equiv); +} + + +static void +push_frame_in_operand (insn, orig, push_size, boundary) + rtx insn, orig; + HOST_WIDE_INT push_size, boundary; +{ + register rtx x = orig; + register enum rtx_code code; + int i, j; + HOST_WIDE_INT offset; + const char *fmt; + + if (x == 0) + return; + + code = GET_CODE (x); + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + case REG: + case ADDRESSOF: + case USE: + return; + + case SET: + /* + skip setjmp setup insn and setjmp restore insn + alpha case: + (set (MEM (reg:SI xx)) (frame_pointer_rtx))) + (set (frame_pointer_rtx) (REG)) + */ + if (GET_CODE (XEXP (x, 0)) == MEM + && XEXP (x, 1) == frame_pointer_rtx) + return; + if (XEXP (x, 0) == frame_pointer_rtx + && GET_CODE (XEXP (x, 1)) == REG) + return; + + /* + powerpc case: restores setjmp address + (set (frame_pointer_rtx) (plus frame_pointer_rtx const_int -n)) + or + (set (reg) (plus frame_pointer_rtx const_int -n)) + (set (frame_pointer_rtx) (reg)) + */ + if (GET_CODE (XEXP (x, 0)) == REG + && GET_CODE (XEXP (x, 1)) == PLUS + && XEXP (XEXP (x, 1), 0) == frame_pointer_rtx + && CONSTANT_P (XEXP (XEXP (x, 1), 1)) + && INTVAL (XEXP (XEXP (x, 1), 1)) < 0) + { + x = XEXP (x, 1); + offset = AUTO_OFFSET(x); + if (x->used || abs (offset) < boundary) + return; + + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset - push_size); + x->used = 1; insn_pushed = TRUE; + return; + } + + /* reset fp_equiv register */ + else if (GET_CODE (XEXP (x, 0)) == REG + && fp_equiv[REGNO (XEXP (x, 0))]) + fp_equiv[REGNO (XEXP (x, 0))] = 0; + + /* propagete fp_equiv register */ + else if (GET_CODE (XEXP (x, 0)) == REG + && GET_CODE (XEXP (x, 1)) == REG + && fp_equiv[REGNO (XEXP (x, 1))]) + if (REGNO (XEXP (x, 0)) <= LAST_VIRTUAL_REGISTER + || reg_renumber[REGNO (XEXP (x, 0))] > 0) + fp_equiv[REGNO (XEXP (x, 0))] = fp_equiv[REGNO (XEXP (x, 1))]; + break; + + case MEM: + if (XEXP (x, 0) == frame_pointer_rtx + && boundary == 0) + { + XEXP (x, 0) = plus_constant (frame_pointer_rtx, push_size); + XEXP (x, 0)->used = 1; insn_pushed = TRUE; + return; + } + break; + + case PLUS: + offset = AUTO_OFFSET(x); + + /* Handle special case of frame register plus constant. */ + if (CONSTANT_P (XEXP (x, 1)) + && XEXP (x, 0) == frame_pointer_rtx) + { + if (x->used || offset < boundary) + return; + + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset + push_size); + x->used = 1; insn_pushed = TRUE; + + return; + } + /* + Handle alpha case: + (plus:SI (subreg:SI (reg:DI 63 FP) 0) (const_int 64 [0x40])) + */ + if (CONSTANT_P (XEXP (x, 1)) + && GET_CODE (XEXP (x, 0)) == SUBREG + && SUBREG_REG (XEXP (x, 0)) == frame_pointer_rtx) + { + if (x->used || offset < boundary) + return; + + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset + push_size); + x->used = 1; insn_pushed = TRUE; + + return; + } + /* + Handle powerpc case: + (set (reg x) (plus fp const)) + (set (.....) (... (plus (reg x) (const B)))) + */ + else if (CONSTANT_P (XEXP (x, 1)) + && GET_CODE (XEXP (x, 0)) == REG + && fp_equiv[REGNO (XEXP (x, 0))]) + { + if (x->used) return; + + offset += fp_equiv[REGNO (XEXP (x, 0))]; + + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset); + x->used = 1; insn_pushed = TRUE; + + return; + } + /* + Handle special case of frame register plus reg (constant). + (set (reg x) (const B)) + (set (....) (...(plus fp (reg x)))) + */ + else if (XEXP (x, 0) == frame_pointer_rtx + && GET_CODE (XEXP (x, 1)) == REG + && PREV_INSN (insn) + && PATTERN (PREV_INSN (insn)) + && SET_DEST (PATTERN (PREV_INSN (insn))) == XEXP (x, 1) + && CONSTANT_P (SET_SRC (PATTERN (PREV_INSN (insn))))) + { + HOST_WIDE_INT offset = INTVAL (SET_SRC (PATTERN (PREV_INSN (insn)))); + + if (x->used || offset < boundary) + return; + + SET_SRC (PATTERN (PREV_INSN (insn))) + = gen_rtx_CONST_INT (VOIDmode, offset + push_size); + x->used = 1; + XEXP (x, 1)->used = 1; + + return; + } + /* Handle special case of frame register plus reg (used). */ + else if (XEXP (x, 0) == frame_pointer_rtx + && XEXP (x, 1)->used) + { + x->used = 1; + return; + } + /* + process further subtree: + Example: (plus:SI (mem/s:SI (plus:SI (reg:SI 17) (const_int 8))) + (const_int 5)) + */ + break; + + case CALL_PLACEHOLDER: + push_frame_of_insns (XEXP (x, 0), push_size, boundary); + push_frame_of_insns (XEXP (x, 1), push_size, boundary); + push_frame_of_insns (XEXP (x, 2), push_size, boundary); + break; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + { + if (XEXP (x, i) == frame_pointer_rtx && boundary == 0) + fatal_insn ("push_frame_in_operand", insn); + push_frame_in_operand (insn, XEXP (x, i), push_size, boundary); + } + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + push_frame_in_operand (insn, XVECEXP (x, i, j), push_size, boundary); +} + +static void +push_frame_of_reg_equiv_memory_loc (push_size, boundary) + HOST_WIDE_INT push_size, boundary; +{ + int i; + extern rtx *reg_equiv_memory_loc; + + /* This function is processed if the push_frame is called from + global_alloc (or reload) function */ + if (reg_equiv_memory_loc == 0) return; + + for (i=LAST_VIRTUAL_REGISTER+1; i < max_regno; i++) + if (reg_equiv_memory_loc[i]) + { + rtx x = reg_equiv_memory_loc[i]; + int offset; + + if (GET_CODE (x) == MEM + && GET_CODE (XEXP (x, 0)) == PLUS + && XEXP (XEXP (x, 0), 0) == frame_pointer_rtx) + { + offset = AUTO_OFFSET(XEXP (x, 0)); + + if (! XEXP (x, 0)->used + && offset >= boundary) + { + offset += push_size; + XEXP (XEXP (x, 0), 1) = gen_rtx_CONST_INT (VOIDmode, offset); + + /* mark */ + XEXP (x, 0)->used = 1; + } + } + else if (GET_CODE (x) == MEM + && XEXP (x, 0) == frame_pointer_rtx + && boundary == 0) + { + XEXP (x, 0) = plus_constant (frame_pointer_rtx, push_size); + XEXP (x, 0)->used = 1; insn_pushed = TRUE; + } + } +} + +static void +push_frame_of_reg_equiv_constant (push_size, boundary) + HOST_WIDE_INT push_size, boundary; +{ + int i; + extern rtx *reg_equiv_constant; + + /* This function is processed if the push_frame is called from + global_alloc (or reload) function */ + if (reg_equiv_constant == 0) return; + + for (i=LAST_VIRTUAL_REGISTER+1; i < max_regno; i++) + if (reg_equiv_constant[i]) + { + rtx x = reg_equiv_constant[i]; + int offset; + + if (GET_CODE (x) == PLUS + && XEXP (x, 0) == frame_pointer_rtx) + { + offset = AUTO_OFFSET(x); + + if (! x->used + && offset >= boundary) + { + offset += push_size; + XEXP (x, 1) = gen_rtx_CONST_INT (VOIDmode, offset); + + /* mark */ + x->used = 1; + } + } + else if (x == frame_pointer_rtx + && boundary == 0) + { + reg_equiv_constant[i] + = plus_constant (frame_pointer_rtx, push_size); + reg_equiv_constant[i]->used = 1; insn_pushed = TRUE; + } + } +} + +static int +check_out_of_frame_access (insn, boundary) + rtx insn; + HOST_WIDE_INT boundary; +{ + for (; insn; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + if (check_out_of_frame_access_in_operand (PATTERN (insn), boundary)) + return TRUE; + } + return FALSE; +} + + +static int +check_out_of_frame_access_in_operand (orig, boundary) + rtx orig; + HOST_WIDE_INT boundary; +{ + register rtx x = orig; + register enum rtx_code code; + int i, j; + const char *fmt; + + if (x == 0) + return FALSE; + + code = GET_CODE (x); + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + case REG: + case ADDRESSOF: + return FALSE; + + case MEM: + if (XEXP (x, 0) == frame_pointer_rtx) + if (0 < boundary) return TRUE; + break; + + case PLUS: + /* Handle special case of frame register plus constant. */ + if (CONSTANT_P (XEXP (x, 1)) + && XEXP (x, 0) == frame_pointer_rtx) + { + if (0 <= AUTO_OFFSET(x) + && AUTO_OFFSET(x) < boundary) return TRUE; + return FALSE; + } + /* + process further subtree: + Example: (plus:SI (mem/s:SI (plus:SI (reg:SI 17) (const_int 8))) + (const_int 5)) + */ + break; + + case CALL_PLACEHOLDER: + if (check_out_of_frame_access (XEXP (x, 0), boundary)) return TRUE; + if (check_out_of_frame_access (XEXP (x, 1), boundary)) return TRUE; + if (check_out_of_frame_access (XEXP (x, 2), boundary)) return TRUE; + break; + + default: + break; + } + + /* Scan all subexpressions. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + if (*fmt == 'e') + { + if (check_out_of_frame_access_in_operand (XEXP (x, i), boundary)) + return TRUE; + } + else if (*fmt == 'E') + for (j = 0; j < XVECLEN (x, i); j++) + if (check_out_of_frame_access_in_operand (XVECEXP (x, i, j), boundary)) + return TRUE; + + return FALSE; +} +#endif