diff options
Diffstat (limited to 'REORG.TODO/sysdeps/generic/unwind-dw2.c')
| -rw-r--r-- | REORG.TODO/sysdeps/generic/unwind-dw2.c | 1306 |
1 files changed, 1306 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/generic/unwind-dw2.c b/REORG.TODO/sysdeps/generic/unwind-dw2.c new file mode 100644 index 0000000000..42b23517d5 --- /dev/null +++ b/REORG.TODO/sysdeps/generic/unwind-dw2.c @@ -0,0 +1,1306 @@ +/* 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 */ |