diff options
Diffstat (limited to 'gcc/unwind-dw2.c')
| -rw-r--r-- | gcc/unwind-dw2.c | 1217 |
1 files changed, 1217 insertions, 0 deletions
diff --git a/gcc/unwind-dw2.c b/gcc/unwind-dw2.c new file mode 100644 index 0000000..e2f20c9 --- /dev/null +++ b/gcc/unwind-dw2.c @@ -0,0 +1,1217 @@ +/* DWARF2 exception handling and frame unwind runtime interface routines. + Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. + + This file is part of GNU CC. + + GNU CC 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. + + GNU CC 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 GNU CC; see the file COPYING. If not, write to + the Free Software Foundation, 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "tconfig.h" +#include "tsystem.h" +#include "dwarf2.h" +#include "unwind.h" +#include "unwind-dw2-fde.h" +#include "gthr.h" + + +#if !USING_SJLJ_EXCEPTIONS + +#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 + +/* This is the register and unwind state for a particular frame. */ +struct _Unwind_Context +{ + void *reg[DWARF_FRAME_REGISTERS+1]; + void *cfa; + void *ra; + void *lsda; + struct dwarf_eh_bases bases; + _Unwind_Word args_size; +}; + +/* Byte size of every register managed by these routines. */ +static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS]; + + +/* 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 { + unsigned int reg; + _Unwind_Sword offset; + 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; + 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; + signed int data_align; + unsigned int code_align; + unsigned char retaddr_column; + unsigned char addr_encoding; + unsigned char saw_z; + unsigned char saw_lsda; +} _Unwind_FrameState; + +/* Decode the unsigned LEB128 constant at BUF into the variable pointed to + by R, and return the new value of BUF. */ + +static unsigned char * +read_uleb128 (unsigned char *buf, _Unwind_Word *r) +{ + unsigned shift = 0; + _Unwind_Word result = 0; + + while (1) + { + unsigned char byte = *buf++; + result |= (byte & 0x7f) << shift; + if ((byte & 0x80) == 0) + break; + shift += 7; + } + *r = result; + return buf; +} + +/* Decode the signed LEB128 constant at BUF into the variable pointed to + by R, and return the new value of BUF. */ + +static unsigned char * +read_sleb128 (unsigned char *buf, _Unwind_Sword *r) +{ + unsigned shift = 0; + _Unwind_Sword result = 0; + unsigned char byte; + + while (1) + { + byte = *buf++; + result |= (byte & 0x7f) << shift; + shift += 7; + if ((byte & 0x80) == 0) + break; + } + if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0) + result |= - (1 << shift); + + *r = result; + return buf; +} + +/* 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 (void *p) { union unaligned *up = p; return up->p; } + +static inline int +read_1u (void *p) { return *(unsigned char *)p; } + +static inline int +read_1s (void *p) { return *(signed char *)p; } + +static inline int +read_2u (void *p) { union unaligned *up = p; return up->u2; } + +static inline int +read_2s (void *p) { union unaligned *up = p; return up->s2; } + +static inline unsigned int +read_4u (void *p) { union unaligned *up = p; return up->u4; } + +static inline int +read_4s (void *p) { union unaligned *up = p; return up->s4; } + +static inline unsigned long +read_8u (void *p) { union unaligned *up = p; return up->u8; } + +static inline unsigned long +read_8s (void *p) { union unaligned *up = p; return up->s8; } + +static unsigned char * +read_encoded_pointer (unsigned char *p, unsigned char encoding, + struct dwarf_eh_bases *bases, void **pptr) +{ + signed long val; + unsigned char *ret; + + switch (encoding & 0x0f) + { + case DW_EH_PE_absptr: + val = (_Unwind_Ptr) read_pointer (p); + ret = p + sizeof (void *); + break; + + case DW_EH_PE_uleb128: + ret = read_uleb128 (p, &val); + break; + case DW_EH_PE_sleb128: + ret = read_sleb128 (p, &val); + break; + + case DW_EH_PE_udata2: + val = read_2u (p); + ret = p + 2; + break; + case DW_EH_PE_udata4: + val = read_4u (p); + ret = p + 4; + break; + case DW_EH_PE_udata8: + val = read_8u (p); + ret = p + 8; + break; + + case DW_EH_PE_sdata2: + val = read_2s (p); + ret = p + 2; + break; + case DW_EH_PE_sdata4: + val = read_4s (p); + ret = p + 4; + break; + case DW_EH_PE_sdata8: + val = read_8s (p); + ret = p + 8; + break; + + default: + abort (); + } + + if (val != 0) + switch (encoding & 0xf0) + { + case DW_EH_PE_absptr: + break; + case DW_EH_PE_pcrel: + val += (_Unwind_Ptr) p; + break; + case DW_EH_PE_textrel: + val += (_Unwind_Ptr) bases->tbase; + break; + case DW_EH_PE_datarel: + val += (_Unwind_Ptr) bases->dbase; + break; + case DW_EH_PE_funcrel: + val += (_Unwind_Ptr) bases->func; + break; + default: + abort (); + } + + *pptr = (void *) (_Unwind_Ptr) val; + return ret; +} + +/* 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]; +} + +/* 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; +} + + +/* 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 unsigned char * +extract_cie_info (struct dwarf_cie *cie, struct _Unwind_Context *context, + _Unwind_FrameState *fs) +{ + unsigned char *aug = cie->augmentation; + unsigned char *p = aug + strlen (aug) + 1; + unsigned char *ret = NULL; + _Unwind_Word code_align; + _Unwind_Sword data_align; + + /* Immediately following the augmentation are the code and + data alignment and return address column. */ + p = read_uleb128 (p, &code_align); + p = read_sleb128 (p, &data_align); + fs->code_align = code_align; + fs->data_align = data_align; + fs->retaddr_column = *p++; + + /* If the augmentation starts with 'z', then a uleb128 immediately + follows containing the length of the augmentation field following + the size. */ + if (*aug == 'z') + { + _Unwind_Word i; + p = read_uleb128 (p, &i); + ret = p + i; + + fs->saw_z = 1; + ++aug; + } + + /* Iterate over recognized augmentation subsequences. */ + while (*aug != '\0') + { + /* "eh" was used by g++ v2; recognize and skip. */ + if (aug[0] == 'e' && aug[1] == 'h') + { + p += sizeof (void *); + aug += 2; + } + + /* "R" indicates a byte indicating how addresses are encoded. */ + else if (aug[0] == 'R') + { + fs->addr_encoding = *p++; + aug += 1; + } + + /* "P" indicates a personality routine in the CIE augmentation + and an lsda pointer in the FDE augmentation. */ + else if (aug[0] == 'P') + { + p = read_encoded_pointer (p, fs->addr_encoding, &context->bases, + (void **) &fs->personality); + fs->saw_lsda = 1; + aug += 1; + } + + /* Otherwise we have an unknown augmentation string. + Bail unless we saw a 'z' prefix. */ + else + return ret; + } + + return ret ? ret : p; +} + + +/* Decode a DW_OP stack program. Return the top of stack. Push INITIAL + onto the stack to start. */ + +static _Unwind_Word +execute_stack_op (unsigned char *op_ptr, 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; + _Unwind_Sword offset; + + 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, &offset); + result = offset; + 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, ®); + result += reg; + break; + } + 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; + } + } + 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]; +} + + +/* 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 (unsigned char *insn_ptr, 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; + + while (insn_ptr < insn_end && fs->pc < context->ra) + { + unsigned char insn = *insn_ptr++; + _Unwind_Word reg, uoffset; + _Unwind_Sword offset; + + if (insn & DW_CFA_advance_loc) + fs->pc += (insn & 0x3f) * fs->code_align; + else if (insn & DW_CFA_offset) + { + reg = insn & 0x3f; + insn_ptr = read_uleb128 (insn_ptr, &uoffset); + offset = (_Unwind_Sword)uoffset * fs->data_align; + fs->regs.reg[reg].how = REG_SAVED_OFFSET; + fs->regs.reg[reg].loc.offset = offset; + } + else if (insn & DW_CFA_restore) + { + reg = insn & 0x3f; + fs->regs.reg[reg].how = REG_UNSAVED; + } + else switch (insn) + { + case DW_CFA_set_loc: + insn_ptr = read_encoded_pointer (insn_ptr, fs->addr_encoding, + &context->bases, &fs->pc); + break; + + case DW_CFA_advance_loc1: + fs->pc += read_1u (insn_ptr); + insn_ptr += 1; + break; + case DW_CFA_advance_loc2: + fs->pc += read_2u (insn_ptr); + insn_ptr += 2; + break; + case DW_CFA_advance_loc4: + fs->pc += read_4u (insn_ptr); + insn_ptr += 4; + break; + + case DW_CFA_offset_extended: + insn_ptr = read_uleb128 (insn_ptr, ®); + insn_ptr = read_uleb128 (insn_ptr, &uoffset); + offset = (_Unwind_Sword)uoffset * 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: + 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 = 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; + 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, &uoffset); + fs->cfa_offset = uoffset; + 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, &uoffset); + fs->cfa_offset = uoffset; + /* cfa_how deliberately not set. */ + break; + + case DW_CFA_def_cfa_expression: + insn_ptr = read_uleb128 (insn_ptr, &uoffset); + fs->cfa_exp = insn_ptr; + fs->cfa_how = CFA_EXP; + insn_ptr += uoffset; + break; + + case DW_CFA_expression: + insn_ptr = read_uleb128 (insn_ptr, ®); + insn_ptr = read_uleb128 (insn_ptr, &uoffset); + fs->regs.reg[reg].how = REG_SAVED_EXP; + fs->regs.reg[reg].loc.exp = insn_ptr; + insn_ptr += uoffset; + break; + + /* From the 2.1 draft. */ + case DW_CFA_offset_extended_sf: + insn_ptr = read_uleb128 (insn_ptr, ®); + insn_ptr = read_sleb128 (insn_ptr, &offset); + offset *= 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_uleb128 (insn_ptr, &fs->cfa_offset); + /* cfa_how deliberately not set. */ + break; + + case DW_CFA_GNU_window_save: + /* ??? Hardcoded for SPARC register window configuration. */ + for (reg = 16; reg < 32; ++reg) + { + fs->regs.reg[reg].how = REG_SAVED_OFFSET; + fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *); + } + 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, &uoffset); + offset = (_Unwind_Sword)uoffset * fs->data_align; + fs->regs.reg[reg].how = REG_SAVED_OFFSET; + fs->regs.reg[reg].loc.offset = -offset; + break; + + default: + abort (); + } + } +} + +static _Unwind_Reason_Code +uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) +{ + struct dwarf_fde *fde; + struct dwarf_cie *cie; + 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 profide 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 + } + + context->bases.func = fde->pc_begin; + fs->pc = fde->pc_begin; + + 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); + insn = NULL; + if (fs->saw_z) + { + _Unwind_Word i; + aug = read_uleb128 (aug, &i); + insn = aug + i; + } + if (fs->saw_lsda) + aug = read_encoded_pointer (aug, fs->addr_encoding, + &context->bases, &context->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; +} + + +static void +uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) +{ + struct _Unwind_Context orig_context = *context; + void *cfa; + long i; + + /* Compute this frame's CFA. */ + switch (fs->cfa_how) + { + case CFA_REG_OFFSET: + /* 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. */ + if (context->reg[fs->cfa_reg] == NULL) + cfa = context->cfa; + else + cfa = (void *) (_Unwind_Ptr) _Unwind_GetGR (context, fs->cfa_reg); + cfa += fs->cfa_offset; + break; + + case CFA_EXP: + /* ??? No way of knowing what register number is the stack pointer + to do the same sort of handling as above. Assume that if the + CFA calculation is so complicated as to require a stack program + that this will not be a problem. */ + { + unsigned char *exp = fs->cfa_exp; + _Unwind_Word len; + + exp = read_uleb128 (exp, &len); + cfa = (void *) (_Unwind_Ptr) + execute_stack_op (exp, exp + len, 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: + { + 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; + } +} + +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; + + 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. */ + context->cfa = outer_cfa; + fs.cfa_how = CFA_REG_OFFSET; + fs.cfa_reg = 0; + 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]); + } + + /* 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; +} + +static inline _Unwind_Ptr +uw_identify_context (struct _Unwind_Context *context) +{ + return _Unwind_GetIP (context); +} + + +#include "unwind.inc" + +#endif /* !USING_SJLJ_EXCEPTIONS */ |