diff options
Diffstat (limited to 'sysdeps/generic/unwind-dw2.c')
| -rw-r--r-- | sysdeps/generic/unwind-dw2.c | 1306 |
1 files changed, 0 insertions, 1306 deletions
diff --git a/sysdeps/generic/unwind-dw2.c b/sysdeps/generic/unwind-dw2.c deleted file mode 100644 index 42b23517d5..0000000000 --- a/sysdeps/generic/unwind-dw2.c +++ /dev/null @@ -1,1306 +0,0 @@ -/* DWARF2 exception handling and frame unwind runtime interface routines. - Copyright (C) 1997-2017 Free Software Foundation, Inc. - - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#ifdef _LIBC -#include <stdlib.h> -#include <string.h> -#include <error.h> -#include <libintl.h> -#include <dwarf2.h> -#include <stdio.h> -#include <unwind.h> -#include <unwind-pe.h> -#include <unwind-dw2-fde.h> -#else -#include "tconfig.h" -#include "tsystem.h" -#include "dwarf2.h" -#include "unwind.h" -#include "unwind-pe.h" -#include "unwind-dw2-fde.h" -#include "gthr.h" -#endif - - - -#ifndef STACK_GROWS_DOWNWARD -#define STACK_GROWS_DOWNWARD 0 -#else -#undef STACK_GROWS_DOWNWARD -#define STACK_GROWS_DOWNWARD 1 -#endif - -/* A target can override (perhaps for backward compatibility) how - many dwarf2 columns are unwound. */ -#ifndef DWARF_FRAME_REGISTERS -#define DWARF_FRAME_REGISTERS FIRST_PSEUDO_REGISTER -#endif - -/* Dwarf frame registers used for pre gcc 3.0 compiled glibc. */ -#ifndef PRE_GCC3_DWARF_FRAME_REGISTERS -#define PRE_GCC3_DWARF_FRAME_REGISTERS DWARF_FRAME_REGISTERS -#endif - -/* This is the register and unwind state for a particular frame. This - provides the information necessary to unwind up past a frame and return - to its caller. */ -struct _Unwind_Context -{ - void *reg[DWARF_FRAME_REGISTERS+1]; - void *cfa; - void *ra; - void *lsda; - struct dwarf_eh_bases bases; - _Unwind_Word args_size; -}; - -#ifndef _LIBC -/* Byte size of every register managed by these routines. */ -static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS]; -#endif - - -/* The result of interpreting the frame unwind info for a frame. - This is all symbolic at this point, as none of the values can - be resolved until the target pc is located. */ -typedef struct -{ - /* Each register save state can be described in terms of a CFA slot, - another register, or a location expression. */ - struct frame_state_reg_info - { - struct { - union { - _Unwind_Word reg; - _Unwind_Sword offset; - const unsigned char *exp; - } loc; - enum { - REG_UNSAVED, - REG_SAVED_OFFSET, - REG_SAVED_REG, - REG_SAVED_EXP, - } how; - } reg[DWARF_FRAME_REGISTERS+1]; - - /* Used to implement DW_CFA_remember_state. */ - struct frame_state_reg_info *prev; - } regs; - - /* The CFA can be described in terms of a reg+offset or a - location expression. */ - _Unwind_Sword cfa_offset; - _Unwind_Word cfa_reg; - const unsigned char *cfa_exp; - enum { - CFA_UNSET, - CFA_REG_OFFSET, - CFA_EXP, - } cfa_how; - - /* The PC described by the current frame state. */ - void *pc; - - /* The information we care about from the CIE/FDE. */ - _Unwind_Personality_Fn personality; - _Unwind_Sword data_align; - _Unwind_Word code_align; - unsigned char retaddr_column; - unsigned char fde_encoding; - unsigned char lsda_encoding; - unsigned char saw_z; - void *eh_ptr; -} _Unwind_FrameState; - -/* Read unaligned data from the instruction buffer. */ - -union unaligned -{ - void *p; - unsigned u2 __attribute__ ((mode (HI))); - unsigned u4 __attribute__ ((mode (SI))); - unsigned u8 __attribute__ ((mode (DI))); - signed s2 __attribute__ ((mode (HI))); - signed s4 __attribute__ ((mode (SI))); - signed s8 __attribute__ ((mode (DI))); -} __attribute__ ((packed)); - -static inline void * -read_pointer (const void *p) { const union unaligned *up = p; return up->p; } - -static inline int -read_1u (const void *p) { return *(const unsigned char *) p; } - -static inline int -read_1s (const void *p) { return *(const signed char *) p; } - -static inline int -read_2u (const void *p) { const union unaligned *up = p; return up->u2; } - -static inline int -read_2s (const void *p) { const union unaligned *up = p; return up->s2; } - -static inline unsigned int -read_4u (const void *p) { const union unaligned *up = p; return up->u4; } - -static inline int -read_4s (const void *p) { const union unaligned *up = p; return up->s4; } - -static inline unsigned long -read_8u (const void *p) { const union unaligned *up = p; return up->u8; } - -static inline unsigned long -read_8s (const void *p) { const union unaligned *up = p; return up->s8; } - -/* Get the value of register REG as saved in CONTEXT. */ - -inline _Unwind_Word -_Unwind_GetGR (struct _Unwind_Context *context, int index) -{ - /* This will segfault if the register hasn't been saved. */ - return * (_Unwind_Word *) context->reg[index]; -} - -/* Get the value of the CFA as saved in CONTEXT. */ - -_Unwind_Word -_Unwind_GetCFA (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->cfa; -} - -/* Overwrite the saved value for register REG in CONTEXT with VAL. */ - -inline void -_Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) -{ - * (_Unwind_Word *) context->reg[index] = val; -} - -/* Retrieve the return address for CONTEXT. */ - -inline _Unwind_Ptr -_Unwind_GetIP (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->ra; -} - -/* Overwrite the return address for CONTEXT with VAL. */ - -inline void -_Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) -{ - context->ra = (void *) val; -} - -void * -_Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) -{ - return context->lsda; -} - -_Unwind_Ptr -_Unwind_GetRegionStart (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.func; -} - -void * -_Unwind_FindEnclosingFunction (void *pc) -{ - struct dwarf_eh_bases bases; - struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases); - if (fde) - return bases.func; - else - return NULL; -} - -#ifndef __ia64__ -_Unwind_Ptr -_Unwind_GetDataRelBase (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.dbase; -} - -_Unwind_Ptr -_Unwind_GetTextRelBase (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.tbase; -} -#endif - -/* Extract any interesting information from the CIE for the translation - unit F belongs to. Return a pointer to the byte after the augmentation, - or NULL if we encountered an undecipherable augmentation. */ - -static const unsigned char * -extract_cie_info (struct dwarf_cie *cie, struct _Unwind_Context *context, - _Unwind_FrameState *fs) -{ - const unsigned char *aug = cie->augmentation; - const unsigned char *p = aug + strlen ((const char *) aug) + 1; - const unsigned char *ret = NULL; - _Unwind_Word utmp; - - /* g++ v2 "eh" has pointer immediately following augmentation string, - so it must be handled first. */ - if (aug[0] == 'e' && aug[1] == 'h') - { - fs->eh_ptr = read_pointer (p); - p += sizeof (void *); - aug += 2; - } - - /* Immediately following the augmentation are the code and - data alignment and return address column. */ - p = read_uleb128 (p, &fs->code_align); - p = read_sleb128 (p, &fs->data_align); - fs->retaddr_column = *p++; - fs->lsda_encoding = DW_EH_PE_omit; - - /* If the augmentation starts with 'z', then a uleb128 immediately - follows containing the length of the augmentation field following - the size. */ - if (*aug == 'z') - { - p = read_uleb128 (p, &utmp); - ret = p + utmp; - - fs->saw_z = 1; - ++aug; - } - - /* Iterate over recognized augmentation subsequences. */ - while (*aug != '\0') - { - /* "L" indicates a byte showing how the LSDA pointer is encoded. */ - if (aug[0] == 'L') - { - fs->lsda_encoding = *p++; - aug += 1; - } - - /* "R" indicates a byte indicating how FDE addresses are encoded. */ - else if (aug[0] == 'R') - { - fs->fde_encoding = *p++; - aug += 1; - } - - /* "P" indicates a personality routine in the CIE augmentation. */ - else if (aug[0] == 'P') - { - _Unwind_Ptr personality; - p = read_encoded_value (context, *p, p + 1, &personality); - fs->personality = (_Unwind_Personality_Fn) personality; - aug += 1; - } - - /* Otherwise we have an unknown augmentation string. - Bail unless we saw a 'z' prefix. */ - else - return ret; - } - - return ret ? ret : p; -} - -#ifndef _LIBC -/* Decode a DW_OP stack program. Return the top of stack. Push INITIAL - onto the stack to start. */ - -static _Unwind_Word -execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end, - struct _Unwind_Context *context, _Unwind_Word initial) -{ - _Unwind_Word stack[64]; /* ??? Assume this is enough. */ - int stack_elt; - - stack[0] = initial; - stack_elt = 1; - - while (op_ptr < op_end) - { - enum dwarf_location_atom op = *op_ptr++; - _Unwind_Word result, reg, utmp; - _Unwind_Sword offset, stmp; - - switch (op) - { - case DW_OP_lit0: - case DW_OP_lit1: - case DW_OP_lit2: - case DW_OP_lit3: - case DW_OP_lit4: - case DW_OP_lit5: - case DW_OP_lit6: - case DW_OP_lit7: - case DW_OP_lit8: - case DW_OP_lit9: - case DW_OP_lit10: - case DW_OP_lit11: - case DW_OP_lit12: - case DW_OP_lit13: - case DW_OP_lit14: - case DW_OP_lit15: - case DW_OP_lit16: - case DW_OP_lit17: - case DW_OP_lit18: - case DW_OP_lit19: - case DW_OP_lit20: - case DW_OP_lit21: - case DW_OP_lit22: - case DW_OP_lit23: - case DW_OP_lit24: - case DW_OP_lit25: - case DW_OP_lit26: - case DW_OP_lit27: - case DW_OP_lit28: - case DW_OP_lit29: - case DW_OP_lit30: - case DW_OP_lit31: - result = op - DW_OP_lit0; - break; - - case DW_OP_addr: - result = (_Unwind_Word) (_Unwind_Ptr) read_pointer (op_ptr); - op_ptr += sizeof (void *); - break; - - case DW_OP_const1u: - result = read_1u (op_ptr); - op_ptr += 1; - break; - case DW_OP_const1s: - result = read_1s (op_ptr); - op_ptr += 1; - break; - case DW_OP_const2u: - result = read_2u (op_ptr); - op_ptr += 2; - break; - case DW_OP_const2s: - result = read_2s (op_ptr); - op_ptr += 2; - break; - case DW_OP_const4u: - result = read_4u (op_ptr); - op_ptr += 4; - break; - case DW_OP_const4s: - result = read_4s (op_ptr); - op_ptr += 4; - break; - case DW_OP_const8u: - result = read_8u (op_ptr); - op_ptr += 8; - break; - case DW_OP_const8s: - result = read_8s (op_ptr); - op_ptr += 8; - break; - case DW_OP_constu: - op_ptr = read_uleb128 (op_ptr, &result); - break; - case DW_OP_consts: - op_ptr = read_sleb128 (op_ptr, &stmp); - result = stmp; - break; - - case DW_OP_reg0: - case DW_OP_reg1: - case DW_OP_reg2: - case DW_OP_reg3: - case DW_OP_reg4: - case DW_OP_reg5: - case DW_OP_reg6: - case DW_OP_reg7: - case DW_OP_reg8: - case DW_OP_reg9: - case DW_OP_reg10: - case DW_OP_reg11: - case DW_OP_reg12: - case DW_OP_reg13: - case DW_OP_reg14: - case DW_OP_reg15: - case DW_OP_reg16: - case DW_OP_reg17: - case DW_OP_reg18: - case DW_OP_reg19: - case DW_OP_reg20: - case DW_OP_reg21: - case DW_OP_reg22: - case DW_OP_reg23: - case DW_OP_reg24: - case DW_OP_reg25: - case DW_OP_reg26: - case DW_OP_reg27: - case DW_OP_reg28: - case DW_OP_reg29: - case DW_OP_reg30: - case DW_OP_reg31: - result = _Unwind_GetGR (context, op - DW_OP_reg0); - break; - case DW_OP_regx: - op_ptr = read_uleb128 (op_ptr, ®); - result = _Unwind_GetGR (context, reg); - break; - - case DW_OP_breg0: - case DW_OP_breg1: - case DW_OP_breg2: - case DW_OP_breg3: - case DW_OP_breg4: - case DW_OP_breg5: - case DW_OP_breg6: - case DW_OP_breg7: - case DW_OP_breg8: - case DW_OP_breg9: - case DW_OP_breg10: - case DW_OP_breg11: - case DW_OP_breg12: - case DW_OP_breg13: - case DW_OP_breg14: - case DW_OP_breg15: - case DW_OP_breg16: - case DW_OP_breg17: - case DW_OP_breg18: - case DW_OP_breg19: - case DW_OP_breg20: - case DW_OP_breg21: - case DW_OP_breg22: - case DW_OP_breg23: - case DW_OP_breg24: - case DW_OP_breg25: - case DW_OP_breg26: - case DW_OP_breg27: - case DW_OP_breg28: - case DW_OP_breg29: - case DW_OP_breg30: - case DW_OP_breg31: - op_ptr = read_sleb128 (op_ptr, &offset); - result = _Unwind_GetGR (context, op - DW_OP_breg0) + offset; - break; - case DW_OP_bregx: - op_ptr = read_uleb128 (op_ptr, ®); - op_ptr = read_sleb128 (op_ptr, &offset); - result = _Unwind_GetGR (context, reg) + offset; - break; - - case DW_OP_dup: - if (stack_elt < 1) - abort (); - result = stack[stack_elt - 1]; - break; - - case DW_OP_drop: - if (--stack_elt < 0) - abort (); - goto no_push; - - case DW_OP_pick: - offset = *op_ptr++; - if (offset >= stack_elt - 1) - abort (); - result = stack[stack_elt - 1 - offset]; - break; - - case DW_OP_over: - if (stack_elt < 2) - abort (); - result = stack[stack_elt - 2]; - break; - - case DW_OP_rot: - { - _Unwind_Word t1, t2, t3; - - if (stack_elt < 3) - abort (); - t1 = stack[stack_elt - 1]; - t2 = stack[stack_elt - 2]; - t3 = stack[stack_elt - 3]; - stack[stack_elt - 1] = t2; - stack[stack_elt - 2] = t3; - stack[stack_elt - 3] = t1; - goto no_push; - } - - case DW_OP_deref: - case DW_OP_deref_size: - case DW_OP_abs: - case DW_OP_neg: - case DW_OP_not: - case DW_OP_plus_uconst: - /* Unary operations. */ - if (--stack_elt < 0) - abort (); - result = stack[stack_elt]; - - switch (op) - { - case DW_OP_deref: - { - void *ptr = (void *) (_Unwind_Ptr) result; - result = (_Unwind_Ptr) read_pointer (ptr); - } - break; - - case DW_OP_deref_size: - { - void *ptr = (void *) (_Unwind_Ptr) result; - switch (*op_ptr++) - { - case 1: - result = read_1u (ptr); - break; - case 2: - result = read_2u (ptr); - break; - case 4: - result = read_4u (ptr); - break; - case 8: - result = read_8u (ptr); - break; - default: - abort (); - } - } - break; - - case DW_OP_abs: - if ((_Unwind_Sword) result < 0) - result = -result; - break; - case DW_OP_neg: - result = -result; - break; - case DW_OP_not: - result = ~result; - break; - case DW_OP_plus_uconst: - op_ptr = read_uleb128 (op_ptr, &utmp); - result += utmp; - break; - - default: - abort (); - } - break; - - case DW_OP_and: - case DW_OP_div: - case DW_OP_minus: - case DW_OP_mod: - case DW_OP_mul: - case DW_OP_or: - case DW_OP_plus: - case DW_OP_le: - case DW_OP_ge: - case DW_OP_eq: - case DW_OP_lt: - case DW_OP_gt: - case DW_OP_ne: - { - /* Binary operations. */ - _Unwind_Word first, second; - if ((stack_elt -= 2) < 0) - abort (); - second = stack[stack_elt]; - first = stack[stack_elt + 1]; - - switch (op) - { - case DW_OP_and: - result = second & first; - break; - case DW_OP_div: - result = (_Unwind_Sword) second / (_Unwind_Sword) first; - break; - case DW_OP_minus: - result = second - first; - break; - case DW_OP_mod: - result = (_Unwind_Sword) second % (_Unwind_Sword) first; - break; - case DW_OP_mul: - result = second * first; - break; - case DW_OP_or: - result = second | first; - break; - case DW_OP_plus: - result = second + first; - break; - case DW_OP_shl: - result = second << first; - break; - case DW_OP_shr: - result = second >> first; - break; - case DW_OP_shra: - result = (_Unwind_Sword) second >> first; - break; - case DW_OP_xor: - result = second ^ first; - break; - case DW_OP_le: - result = (_Unwind_Sword) first <= (_Unwind_Sword) second; - break; - case DW_OP_ge: - result = (_Unwind_Sword) first >= (_Unwind_Sword) second; - break; - case DW_OP_eq: - result = (_Unwind_Sword) first == (_Unwind_Sword) second; - break; - case DW_OP_lt: - result = (_Unwind_Sword) first < (_Unwind_Sword) second; - break; - case DW_OP_gt: - result = (_Unwind_Sword) first > (_Unwind_Sword) second; - break; - case DW_OP_ne: - result = (_Unwind_Sword) first != (_Unwind_Sword) second; - break; - - default: - abort (); - } - } - break; - - case DW_OP_skip: - offset = read_2s (op_ptr); - op_ptr += 2; - op_ptr += offset; - goto no_push; - - case DW_OP_bra: - if (--stack_elt < 0) - abort (); - offset = read_2s (op_ptr); - op_ptr += 2; - if (stack[stack_elt] != 0) - op_ptr += offset; - goto no_push; - - case DW_OP_nop: - goto no_push; - - default: - abort (); - } - - /* Most things push a result value. */ - if ((size_t) stack_elt >= sizeof(stack)/sizeof(*stack)) - abort (); - stack[stack_elt++] = result; - no_push:; - } - - /* We were executing this program to get a value. It should be - at top of stack. */ - if (--stack_elt < 0) - abort (); - return stack[stack_elt]; -} -#endif - -/* Decode DWARF 2 call frame information. Takes pointers the - instruction sequence to decode, current register information and - CIE info, and the PC range to evaluate. */ - -static void -execute_cfa_program (const unsigned char *insn_ptr, - const unsigned char *insn_end, - struct _Unwind_Context *context, - _Unwind_FrameState *fs) -{ - struct frame_state_reg_info *unused_rs = NULL; - - /* Don't allow remember/restore between CIE and FDE programs. */ - fs->regs.prev = NULL; - - /* The comparison with the return address uses < rather than <= because - we are only interested in the effects of code before the call; for a - noreturn function, the return address may point to unrelated code with - a different stack configuration that we are not interested in. We - assume that the call itself is unwind info-neutral; if not, or if - there are delay instructions that adjust the stack, these must be - reflected at the point immediately before the call insn. */ - while (insn_ptr < insn_end && fs->pc < context->ra) - { - unsigned char insn = *insn_ptr++; - _Unwind_Word reg, utmp; - _Unwind_Sword offset, stmp; - - if ((insn & 0xc0) == DW_CFA_advance_loc) - fs->pc += (insn & 0x3f) * fs->code_align; - else if ((insn & 0xc0) == DW_CFA_offset) - { - reg = insn & 0x3f; - insn_ptr = read_uleb128 (insn_ptr, &utmp); - offset = (_Unwind_Sword) utmp * fs->data_align; - fs->regs.reg[reg].how = REG_SAVED_OFFSET; - fs->regs.reg[reg].loc.offset = offset; - } - else if ((insn & 0xc0) == DW_CFA_restore) - { - reg = insn & 0x3f; - fs->regs.reg[reg].how = REG_UNSAVED; - } - else switch (insn) - { - case DW_CFA_set_loc: - { - _Unwind_Ptr pc; - insn_ptr = read_encoded_value (context, fs->fde_encoding, - insn_ptr, &pc); - fs->pc = (void *) pc; - } - break; - - case DW_CFA_advance_loc1: - fs->pc += read_1u (insn_ptr) * fs->code_align; - insn_ptr += 1; - break; - case DW_CFA_advance_loc2: - fs->pc += read_2u (insn_ptr) * fs->code_align; - insn_ptr += 2; - break; - case DW_CFA_advance_loc4: - fs->pc += read_4u (insn_ptr) * fs->code_align; - insn_ptr += 4; - break; - - case DW_CFA_offset_extended: - insn_ptr = read_uleb128 (insn_ptr, ®); - insn_ptr = read_uleb128 (insn_ptr, &utmp); - offset = (_Unwind_Sword) utmp * fs->data_align; - fs->regs.reg[reg].how = REG_SAVED_OFFSET; - fs->regs.reg[reg].loc.offset = offset; - break; - - case DW_CFA_restore_extended: - insn_ptr = read_uleb128 (insn_ptr, ®); - fs->regs.reg[reg].how = REG_UNSAVED; - break; - - case DW_CFA_undefined: - case DW_CFA_same_value: - insn_ptr = read_uleb128 (insn_ptr, ®); - break; - - case DW_CFA_nop: - break; - - case DW_CFA_register: - { - _Unwind_Word reg2; - insn_ptr = read_uleb128 (insn_ptr, ®); - insn_ptr = read_uleb128 (insn_ptr, ®2); - fs->regs.reg[reg].how = REG_SAVED_REG; - fs->regs.reg[reg].loc.reg = reg2; - } - break; - - case DW_CFA_remember_state: - { - struct frame_state_reg_info *new_rs; - if (unused_rs) - { - new_rs = unused_rs; - unused_rs = unused_rs->prev; - } - else - new_rs = __builtin_alloca (sizeof (struct frame_state_reg_info)); - - *new_rs = fs->regs; - fs->regs.prev = new_rs; - } - break; - - case DW_CFA_restore_state: - { - struct frame_state_reg_info *old_rs = fs->regs.prev; -#ifdef _LIBC - if (old_rs == NULL) - __libc_fatal ("invalid DWARF unwind data"); - else -#endif - { - fs->regs = *old_rs; - old_rs->prev = unused_rs; - unused_rs = old_rs; - } - } - break; - - case DW_CFA_def_cfa: - insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); - insn_ptr = read_uleb128 (insn_ptr, &utmp); - fs->cfa_offset = utmp; - fs->cfa_how = CFA_REG_OFFSET; - break; - - case DW_CFA_def_cfa_register: - insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); - fs->cfa_how = CFA_REG_OFFSET; - break; - - case DW_CFA_def_cfa_offset: - insn_ptr = read_uleb128 (insn_ptr, &utmp); - fs->cfa_offset = utmp; - /* cfa_how deliberately not set. */ - break; - - case DW_CFA_def_cfa_expression: - fs->cfa_exp = insn_ptr; - fs->cfa_how = CFA_EXP; - insn_ptr = read_uleb128 (insn_ptr, &utmp); - insn_ptr += utmp; - break; - - case DW_CFA_expression: - insn_ptr = read_uleb128 (insn_ptr, ®); - fs->regs.reg[reg].how = REG_SAVED_EXP; - fs->regs.reg[reg].loc.exp = insn_ptr; - insn_ptr = read_uleb128 (insn_ptr, &utmp); - insn_ptr += utmp; - break; - - /* From the 2.1 draft. */ - case DW_CFA_offset_extended_sf: - insn_ptr = read_uleb128 (insn_ptr, ®); - insn_ptr = read_sleb128 (insn_ptr, &stmp); - offset = stmp * fs->data_align; - fs->regs.reg[reg].how = REG_SAVED_OFFSET; - fs->regs.reg[reg].loc.offset = offset; - break; - - case DW_CFA_def_cfa_sf: - insn_ptr = read_uleb128 (insn_ptr, &fs->cfa_reg); - insn_ptr = read_sleb128 (insn_ptr, &fs->cfa_offset); - fs->cfa_how = CFA_REG_OFFSET; - break; - - case DW_CFA_def_cfa_offset_sf: - insn_ptr = read_sleb128 (insn_ptr, &fs->cfa_offset); - /* cfa_how deliberately not set. */ - break; - - case DW_CFA_GNU_window_save: - /* ??? Hardcoded for SPARC register window configuration. - At least do not do anything for archs which explicitly - define a lower register number. */ -#if DWARF_FRAME_REGISTERS >= 32 - for (reg = 16; reg < 32; ++reg) - { - fs->regs.reg[reg].how = REG_SAVED_OFFSET; - fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *); - } -#endif - break; - - case DW_CFA_GNU_args_size: - insn_ptr = read_uleb128 (insn_ptr, &context->args_size); - break; - - case DW_CFA_GNU_negative_offset_extended: - /* Obsoleted by DW_CFA_offset_extended_sf, but used by - older PowerPC code. */ - insn_ptr = read_uleb128 (insn_ptr, ®); - insn_ptr = read_uleb128 (insn_ptr, &utmp); - offset = (_Unwind_Word) utmp * fs->data_align; - fs->regs.reg[reg].how = REG_SAVED_OFFSET; - fs->regs.reg[reg].loc.offset = -offset; - break; - - default: - abort (); - } - } -} - -/* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for - its caller and decode it into FS. This function also sets the - args_size and lsda members of CONTEXT, as they are really information - about the caller's frame. */ - -static _Unwind_Reason_Code -uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - struct dwarf_fde *fde; - struct dwarf_cie *cie; - const unsigned char *aug, *insn, *end; - - memset (fs, 0, sizeof (*fs)); - context->args_size = 0; - context->lsda = 0; - - fde = _Unwind_Find_FDE (context->ra - 1, &context->bases); - if (fde == NULL) - { - /* Couldn't find frame unwind info for this function. Try a - target-specific fallback mechanism. This will necessarily - not provide a personality routine or LSDA. */ -#ifdef MD_FALLBACK_FRAME_STATE_FOR - MD_FALLBACK_FRAME_STATE_FOR (context, fs, success); - return _URC_END_OF_STACK; - success: - return _URC_NO_REASON; -#else - return _URC_END_OF_STACK; -#endif - } - - fs->pc = context->bases.func; - - cie = get_cie (fde); - insn = extract_cie_info (cie, context, fs); - if (insn == NULL) - /* CIE contained unknown augmentation. */ - return _URC_FATAL_PHASE1_ERROR; - - /* First decode all the insns in the CIE. */ - end = (unsigned char *) next_fde ((struct dwarf_fde *) cie); - execute_cfa_program (insn, end, context, fs); - - /* Locate augmentation for the fde. */ - aug = (unsigned char *) fde + sizeof (*fde); - aug += 2 * size_of_encoded_value (fs->fde_encoding); - insn = NULL; - if (fs->saw_z) - { - _Unwind_Word i; - aug = read_uleb128 (aug, &i); - insn = aug + i; - } - if (fs->lsda_encoding != DW_EH_PE_omit) - { - _Unwind_Ptr lsda; - aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda); - context->lsda = (void *) lsda; - } - - /* Then the insns in the FDE up to our target PC. */ - if (insn == NULL) - insn = aug; - end = (unsigned char *) next_fde (fde); - execute_cfa_program (insn, end, context, fs); - - return _URC_NO_REASON; -} - -typedef struct frame_state -{ - void *cfa; - void *eh_ptr; - long cfa_offset; - long args_size; - long reg_or_offset[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; - unsigned short cfa_reg; - unsigned short retaddr_column; - char saved[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; -} frame_state; - -#ifndef STATIC -# define STATIC -#endif - -STATIC -struct frame_state * __frame_state_for (void *, struct frame_state *); - -/* Called from pre-G++ 3.0 __throw to find the registers to restore for - a given PC_TARGET. The caller should allocate a local variable of - `struct frame_state' and pass its address to STATE_IN. */ - -STATIC -struct frame_state * -__frame_state_for (void *pc_target, struct frame_state *state_in) -{ - struct _Unwind_Context context; - _Unwind_FrameState fs; - int reg; - - memset (&context, 0, sizeof (struct _Unwind_Context)); - context.ra = pc_target + 1; - - if (uw_frame_state_for (&context, &fs) != _URC_NO_REASON) - return 0; - - /* We have no way to pass a location expression for the CFA to our - caller. It wouldn't understand it anyway. */ - if (fs.cfa_how == CFA_EXP) - return 0; - - for (reg = 0; reg < PRE_GCC3_DWARF_FRAME_REGISTERS + 1; reg++) - { - state_in->saved[reg] = fs.regs.reg[reg].how; - switch (state_in->saved[reg]) - { - case REG_SAVED_REG: - state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.reg; - break; - case REG_SAVED_OFFSET: - state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.offset; - break; - default: - state_in->reg_or_offset[reg] = 0; - break; - } - } - - state_in->cfa_offset = fs.cfa_offset; - state_in->cfa_reg = fs.cfa_reg; - state_in->retaddr_column = fs.retaddr_column; - state_in->args_size = context.args_size; - state_in->eh_ptr = fs.eh_ptr; - - return state_in; -} - -#ifndef _LIBC - -static void -uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - struct _Unwind_Context orig_context = *context; - void *cfa; - long i; - -#ifdef EH_RETURN_STACKADJ_RTX - /* Special handling here: Many machines do not use a frame pointer, - and track the CFA only through offsets from the stack pointer from - one frame to the next. In this case, the stack pointer is never - stored, so it has no saved address in the context. What we do - have is the CFA from the previous stack frame. - - In very special situations (such as unwind info for signal return), - there may be location expressions that use the stack pointer as well. - - Do this conditionally for one frame. This allows the unwind info - for one frame to save a copy of the stack pointer from the previous - frame, and be able to use much easier CFA mechanisms to do it. - Always zap the saved stack pointer value for the next frame; carrying - the value over from one frame to another doesn't make sense. */ - - _Unwind_Word tmp_sp; - - if (!orig_context.reg[__builtin_dwarf_sp_column ()]) - { - tmp_sp = (_Unwind_Ptr) context->cfa; - orig_context.reg[__builtin_dwarf_sp_column ()] = &tmp_sp; - } - context->reg[__builtin_dwarf_sp_column ()] = NULL; -#endif - - /* Compute this frame's CFA. */ - switch (fs->cfa_how) - { - case CFA_REG_OFFSET: - cfa = (void *) (_Unwind_Ptr) _Unwind_GetGR (&orig_context, fs->cfa_reg); - cfa += fs->cfa_offset; - break; - - case CFA_EXP: - { - const unsigned char *exp = fs->cfa_exp; - _Unwind_Word len; - - exp = read_uleb128 (exp, &len); - cfa = (void *) (_Unwind_Ptr) - execute_stack_op (exp, exp + len, &orig_context, 0); - break; - } - - default: - abort (); - } - context->cfa = cfa; - - /* Compute the addresses of all registers saved in this frame. */ - for (i = 0; i < DWARF_FRAME_REGISTERS + 1; ++i) - switch (fs->regs.reg[i].how) - { - case REG_UNSAVED: - break; - - case REG_SAVED_OFFSET: - context->reg[i] = cfa + fs->regs.reg[i].loc.offset; - break; - - case REG_SAVED_REG: - context->reg[i] = orig_context.reg[fs->regs.reg[i].loc.reg]; - break; - - case REG_SAVED_EXP: - { - const unsigned char *exp = fs->regs.reg[i].loc.exp; - _Unwind_Word len; - _Unwind_Ptr val; - - exp = read_uleb128 (exp, &len); - val = execute_stack_op (exp, exp + len, &orig_context, - (_Unwind_Ptr) cfa); - context->reg[i] = (void *) val; - } - break; - } -} - -/* CONTEXT describes the unwind state for a frame, and FS describes the FDE - of its caller. Update CONTEXT to refer to the caller as well. Note - that the args_size and lsda members are not updated here, but later in - uw_frame_state_for. */ - -static void -uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - uw_update_context_1 (context, fs); - - /* Compute the return address now, since the return address column - can change from frame to frame. */ - context->ra = __builtin_extract_return_addr - ((void *) (_Unwind_Ptr) _Unwind_GetGR (context, fs->retaddr_column)); -} - -/* Fill in CONTEXT for top-of-stack. The only valid registers at this - level will be the return address and the CFA. */ - -#define uw_init_context(CONTEXT) \ - do \ - { \ - /* Do any necessary initialization to access arbitrary stack frames. \ - On the SPARC, this means flushing the register windows. */ \ - __builtin_unwind_init (); \ - uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \ - __builtin_return_address (0)); \ - } \ - while (0) - -static void -uw_init_context_1 (struct _Unwind_Context *context, - void *outer_cfa, void *outer_ra) -{ - void *ra = __builtin_extract_return_addr (__builtin_return_address (0)); - _Unwind_FrameState fs; - _Unwind_Word sp_slot; - - memset (context, 0, sizeof (struct _Unwind_Context)); - context->ra = ra; - - if (uw_frame_state_for (context, &fs) != _URC_NO_REASON) - abort (); - - /* Force the frame state to use the known cfa value. */ - sp_slot = (_Unwind_Ptr) outer_cfa; - context->reg[__builtin_dwarf_sp_column ()] = &sp_slot; - fs.cfa_how = CFA_REG_OFFSET; - fs.cfa_reg = __builtin_dwarf_sp_column (); - fs.cfa_offset = 0; - - uw_update_context_1 (context, &fs); - - /* If the return address column was saved in a register in the - initialization context, then we can't see it in the given - call frame data. So have the initialization context tell us. */ - context->ra = __builtin_extract_return_addr (outer_ra); -} - - -/* Install TARGET into CURRENT so that we can return to it. This is a - macro because __builtin_eh_return must be invoked in the context of - our caller. */ - -#define uw_install_context(CURRENT, TARGET) \ - do \ - { \ - long offset = uw_install_context_1 ((CURRENT), (TARGET)); \ - void *handler = __builtin_frob_return_addr ((TARGET)->ra); \ - __builtin_eh_return (offset, handler); \ - } \ - while (0) - -static inline void -init_dwarf_reg_size_table (void) -{ - __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table); -} - -static long -uw_install_context_1 (struct _Unwind_Context *current, - struct _Unwind_Context *target) -{ - long i; - -#if __GTHREADS - { - static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT; - if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0 - || dwarf_reg_size_table[0] == 0) - init_dwarf_reg_size_table (); - } -#else - if (dwarf_reg_size_table[0] == 0) - init_dwarf_reg_size_table (); -#endif - - for (i = 0; i < DWARF_FRAME_REGISTERS; ++i) - { - void *c = current->reg[i]; - void *t = target->reg[i]; - if (t && c && t != c) - memcpy (c, t, dwarf_reg_size_table[i]); - } - -#ifdef EH_RETURN_STACKADJ_RTX - { - void *target_cfa; - - /* If the last frame records a saved stack pointer, use it. */ - if (target->reg[__builtin_dwarf_sp_column ()]) - target_cfa = (void *)(_Unwind_Ptr) - _Unwind_GetGR (target, __builtin_dwarf_sp_column ()); - else - target_cfa = target->cfa; - - /* We adjust SP by the difference between CURRENT and TARGET's CFA. */ - if (STACK_GROWS_DOWNWARD) - return target_cfa - current->cfa + target->args_size; - else - return current->cfa - target_cfa - target->args_size; - } -#else - return 0; -#endif -} - -static inline _Unwind_Ptr -uw_identify_context (struct _Unwind_Context *context) -{ - return _Unwind_GetIP (context); -} - - -#include "unwind.inc" - -#endif /* _LIBC */ |