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Diffstat (limited to 'libgcc/config/arm/unwind-arm.c')
| -rw-r--r-- | libgcc/config/arm/unwind-arm.c | 1283 |
1 files changed, 1283 insertions, 0 deletions
diff --git a/libgcc/config/arm/unwind-arm.c b/libgcc/config/arm/unwind-arm.c new file mode 100644 index 00000000000..90d258d3c80 --- /dev/null +++ b/libgcc/config/arm/unwind-arm.c @@ -0,0 +1,1283 @@ +/* ARM EABI compliant unwinding routines. + Copyright (C) 2004, 2005, 2009 Free Software Foundation, Inc. + Contributed by Paul Brook + + This file 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 3, or (at your option) any + later version. + + This file 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. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + <http://www.gnu.org/licenses/>. */ + +#include "unwind.h" + +/* We add a prototype for abort here to avoid creating a dependency on + target headers. */ +extern void abort (void); + +/* Definitions for C++ runtime support routines. We make these weak + declarations to avoid pulling in libsupc++ unnecessarily. */ +typedef unsigned char bool; + +typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */ +enum __cxa_type_match_result + { + ctm_failed = 0, + ctm_succeeded = 1, + ctm_succeeded_with_ptr_to_base = 2 + }; + +void __attribute__((weak)) __cxa_call_unexpected(_Unwind_Control_Block *ucbp); +bool __attribute__((weak)) __cxa_begin_cleanup(_Unwind_Control_Block *ucbp); +enum __cxa_type_match_result __attribute__((weak)) __cxa_type_match + (_Unwind_Control_Block *ucbp, const type_info *rttip, + bool is_reference, void **matched_object); + +_Unwind_Ptr __attribute__((weak)) +__gnu_Unwind_Find_exidx (_Unwind_Ptr, int *); + +/* Misc constants. */ +#define R_IP 12 +#define R_SP 13 +#define R_LR 14 +#define R_PC 15 + +#define EXIDX_CANTUNWIND 1 +#define uint32_highbit (((_uw) 1) << 31) + +#define UCB_FORCED_STOP_FN(ucbp) ((ucbp)->unwinder_cache.reserved1) +#define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2) +#define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3) +#define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4) + +struct core_regs +{ + _uw r[16]; +}; + +/* We use normal integer types here to avoid the compiler generating + coprocessor instructions. */ +struct vfp_regs +{ + _uw64 d[16]; + _uw pad; +}; + +struct vfpv3_regs +{ + /* Always populated via VSTM, so no need for the "pad" field from + vfp_regs (which is used to store the format word for FSTMX). */ + _uw64 d[16]; +}; + +struct fpa_reg +{ + _uw w[3]; +}; + +struct fpa_regs +{ + struct fpa_reg f[8]; +}; + +struct wmmxd_regs +{ + _uw64 wd[16]; +}; + +struct wmmxc_regs +{ + _uw wc[4]; +}; + +/* Unwind descriptors. */ + +typedef struct +{ + _uw16 length; + _uw16 offset; +} EHT16; + +typedef struct +{ + _uw length; + _uw offset; +} EHT32; + +/* The ABI specifies that the unwind routines may only use core registers, + except when actually manipulating coprocessor state. This allows + us to write one implementation that works on all platforms by + demand-saving coprocessor registers. + + During unwinding we hold the coprocessor state in the actual hardware + registers and allocate demand-save areas for use during phase1 + unwinding. */ + +typedef struct +{ + /* The first fields must be the same as a phase2_vrs. */ + _uw demand_save_flags; + struct core_regs core; + _uw prev_sp; /* Only valid during forced unwinding. */ + struct vfp_regs vfp; + struct vfpv3_regs vfp_regs_16_to_31; + struct fpa_regs fpa; + struct wmmxd_regs wmmxd; + struct wmmxc_regs wmmxc; +} phase1_vrs; + +#define DEMAND_SAVE_VFP 1 /* VFP state has been saved if not set */ +#define DEMAND_SAVE_VFP_D 2 /* VFP state is for FLDMD/FSTMD if set */ +#define DEMAND_SAVE_VFP_V3 4 /* VFPv3 state for regs 16 .. 31 has + been saved if not set */ +#define DEMAND_SAVE_WMMXD 8 /* iWMMXt data registers have been + saved if not set. */ +#define DEMAND_SAVE_WMMXC 16 /* iWMMXt control registers have been + saved if not set. */ + +/* This must match the structure created by the assembly wrappers. */ +typedef struct +{ + _uw demand_save_flags; + struct core_regs core; +} phase2_vrs; + + +/* An exception index table entry. */ + +typedef struct __EIT_entry +{ + _uw fnoffset; + _uw content; +} __EIT_entry; + +/* Assembly helper functions. */ + +/* Restore core register state. Never returns. */ +void __attribute__((noreturn)) restore_core_regs (struct core_regs *); + + +/* Coprocessor register state manipulation functions. */ + +/* Routines for FLDMX/FSTMX format... */ +void __gnu_Unwind_Save_VFP (struct vfp_regs * p); +void __gnu_Unwind_Restore_VFP (struct vfp_regs * p); +void __gnu_Unwind_Save_WMMXD (struct wmmxd_regs * p); +void __gnu_Unwind_Restore_WMMXD (struct wmmxd_regs * p); +void __gnu_Unwind_Save_WMMXC (struct wmmxc_regs * p); +void __gnu_Unwind_Restore_WMMXC (struct wmmxc_regs * p); + +/* ...and those for FLDMD/FSTMD format... */ +void __gnu_Unwind_Save_VFP_D (struct vfp_regs * p); +void __gnu_Unwind_Restore_VFP_D (struct vfp_regs * p); + +/* ...and those for VLDM/VSTM format, saving/restoring only registers + 16 through 31. */ +void __gnu_Unwind_Save_VFP_D_16_to_31 (struct vfpv3_regs * p); +void __gnu_Unwind_Restore_VFP_D_16_to_31 (struct vfpv3_regs * p); + +/* Restore coprocessor state after phase1 unwinding. */ +static void +restore_non_core_regs (phase1_vrs * vrs) +{ + if ((vrs->demand_save_flags & DEMAND_SAVE_VFP) == 0) + { + if (vrs->demand_save_flags & DEMAND_SAVE_VFP_D) + __gnu_Unwind_Restore_VFP_D (&vrs->vfp); + else + __gnu_Unwind_Restore_VFP (&vrs->vfp); + } + + if ((vrs->demand_save_flags & DEMAND_SAVE_VFP_V3) == 0) + __gnu_Unwind_Restore_VFP_D_16_to_31 (&vrs->vfp_regs_16_to_31); + + if ((vrs->demand_save_flags & DEMAND_SAVE_WMMXD) == 0) + __gnu_Unwind_Restore_WMMXD (&vrs->wmmxd); + if ((vrs->demand_save_flags & DEMAND_SAVE_WMMXC) == 0) + __gnu_Unwind_Restore_WMMXC (&vrs->wmmxc); +} + +/* A better way to do this would probably be to compare the absolute address + with a segment relative relocation of the same symbol. */ + +extern int __text_start; +extern int __data_start; + +/* The exception index table location. */ +extern __EIT_entry __exidx_start; +extern __EIT_entry __exidx_end; + +/* ABI defined personality routines. */ +extern _Unwind_Reason_Code __aeabi_unwind_cpp_pr0 (_Unwind_State, + _Unwind_Control_Block *, _Unwind_Context *);// __attribute__((weak)); +extern _Unwind_Reason_Code __aeabi_unwind_cpp_pr1 (_Unwind_State, + _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak)); +extern _Unwind_Reason_Code __aeabi_unwind_cpp_pr2 (_Unwind_State, + _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak)); + +/* ABI defined routine to store a virtual register to memory. */ + +_Unwind_VRS_Result _Unwind_VRS_Get (_Unwind_Context *context, + _Unwind_VRS_RegClass regclass, + _uw regno, + _Unwind_VRS_DataRepresentation representation, + void *valuep) +{ + phase1_vrs *vrs = (phase1_vrs *) context; + + switch (regclass) + { + case _UVRSC_CORE: + if (representation != _UVRSD_UINT32 + || regno > 15) + return _UVRSR_FAILED; + *(_uw *) valuep = vrs->core.r[regno]; + return _UVRSR_OK; + + case _UVRSC_VFP: + case _UVRSC_FPA: + case _UVRSC_WMMXD: + case _UVRSC_WMMXC: + return _UVRSR_NOT_IMPLEMENTED; + + default: + return _UVRSR_FAILED; + } +} + + +/* ABI defined function to load a virtual register from memory. */ + +_Unwind_VRS_Result _Unwind_VRS_Set (_Unwind_Context *context, + _Unwind_VRS_RegClass regclass, + _uw regno, + _Unwind_VRS_DataRepresentation representation, + void *valuep) +{ + phase1_vrs *vrs = (phase1_vrs *) context; + + switch (regclass) + { + case _UVRSC_CORE: + if (representation != _UVRSD_UINT32 + || regno > 15) + return _UVRSR_FAILED; + + vrs->core.r[regno] = *(_uw *) valuep; + return _UVRSR_OK; + + case _UVRSC_VFP: + case _UVRSC_FPA: + case _UVRSC_WMMXD: + case _UVRSC_WMMXC: + return _UVRSR_NOT_IMPLEMENTED; + + default: + return _UVRSR_FAILED; + } +} + + +/* ABI defined function to pop registers off the stack. */ + +_Unwind_VRS_Result _Unwind_VRS_Pop (_Unwind_Context *context, + _Unwind_VRS_RegClass regclass, + _uw discriminator, + _Unwind_VRS_DataRepresentation representation) +{ + phase1_vrs *vrs = (phase1_vrs *) context; + + switch (regclass) + { + case _UVRSC_CORE: + { + _uw *ptr; + _uw mask; + int i; + + if (representation != _UVRSD_UINT32) + return _UVRSR_FAILED; + + mask = discriminator & 0xffff; + ptr = (_uw *) vrs->core.r[R_SP]; + /* Pop the requested registers. */ + for (i = 0; i < 16; i++) + { + if (mask & (1 << i)) + vrs->core.r[i] = *(ptr++); + } + /* Writeback the stack pointer value if it wasn't restored. */ + if ((mask & (1 << R_SP)) == 0) + vrs->core.r[R_SP] = (_uw) ptr; + } + return _UVRSR_OK; + + case _UVRSC_VFP: + { + _uw start = discriminator >> 16; + _uw count = discriminator & 0xffff; + struct vfp_regs tmp; + struct vfpv3_regs tmp_16_to_31; + int tmp_count; + _uw *sp; + _uw *dest; + int num_vfpv3_regs = 0; + + /* We use an approximation here by bounding _UVRSD_DOUBLE + register numbers at 32 always, since we can't detect if + VFPv3 isn't present (in such a case the upper limit is 16). */ + if ((representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE) + || start + count > (representation == _UVRSD_VFPX ? 16 : 32) + || (representation == _UVRSD_VFPX && start >= 16)) + return _UVRSR_FAILED; + + /* Check if we're being asked to pop VFPv3-only registers + (numbers 16 through 31). */ + if (start >= 16) + num_vfpv3_regs = count; + else if (start + count > 16) + num_vfpv3_regs = start + count - 16; + + if (num_vfpv3_regs && representation != _UVRSD_DOUBLE) + return _UVRSR_FAILED; + + /* Demand-save coprocessor registers for stage1. */ + if (start < 16 && (vrs->demand_save_flags & DEMAND_SAVE_VFP)) + { + vrs->demand_save_flags &= ~DEMAND_SAVE_VFP; + + if (representation == _UVRSD_DOUBLE) + { + /* Save in FLDMD/FSTMD format. */ + vrs->demand_save_flags |= DEMAND_SAVE_VFP_D; + __gnu_Unwind_Save_VFP_D (&vrs->vfp); + } + else + { + /* Save in FLDMX/FSTMX format. */ + vrs->demand_save_flags &= ~DEMAND_SAVE_VFP_D; + __gnu_Unwind_Save_VFP (&vrs->vfp); + } + } + + if (num_vfpv3_regs > 0 + && (vrs->demand_save_flags & DEMAND_SAVE_VFP_V3)) + { + vrs->demand_save_flags &= ~DEMAND_SAVE_VFP_V3; + __gnu_Unwind_Save_VFP_D_16_to_31 (&vrs->vfp_regs_16_to_31); + } + + /* Restore the registers from the stack. Do this by saving the + current VFP registers to a memory area, moving the in-memory + values into that area, and restoring from the whole area. + For _UVRSD_VFPX we assume FSTMX standard format 1. */ + if (representation == _UVRSD_VFPX) + __gnu_Unwind_Save_VFP (&tmp); + else + { + /* Save registers 0 .. 15 if required. */ + if (start < 16) + __gnu_Unwind_Save_VFP_D (&tmp); + + /* Save VFPv3 registers 16 .. 31 if required. */ + if (num_vfpv3_regs) + __gnu_Unwind_Save_VFP_D_16_to_31 (&tmp_16_to_31); + } + + /* Work out how many registers below register 16 need popping. */ + tmp_count = num_vfpv3_regs > 0 ? 16 - start : count; + + /* Copy registers below 16, if needed. + The stack address is only guaranteed to be word aligned, so + we can't use doubleword copies. */ + sp = (_uw *) vrs->core.r[R_SP]; + if (tmp_count > 0) + { + tmp_count *= 2; + dest = (_uw *) &tmp.d[start]; + while (tmp_count--) + *(dest++) = *(sp++); + } + + /* Copy VFPv3 registers numbered >= 16, if needed. */ + if (num_vfpv3_regs > 0) + { + /* num_vfpv3_regs is needed below, so copy it. */ + int tmp_count_2 = num_vfpv3_regs * 2; + int vfpv3_start = start < 16 ? 16 : start; + + dest = (_uw *) &tmp_16_to_31.d[vfpv3_start - 16]; + while (tmp_count_2--) + *(dest++) = *(sp++); + } + + /* Skip the format word space if using FLDMX/FSTMX format. */ + if (representation == _UVRSD_VFPX) + sp++; + + /* Set the new stack pointer. */ + vrs->core.r[R_SP] = (_uw) sp; + + /* Reload the registers. */ + if (representation == _UVRSD_VFPX) + __gnu_Unwind_Restore_VFP (&tmp); + else + { + /* Restore registers 0 .. 15 if required. */ + if (start < 16) + __gnu_Unwind_Restore_VFP_D (&tmp); + + /* Restore VFPv3 registers 16 .. 31 if required. */ + if (num_vfpv3_regs > 0) + __gnu_Unwind_Restore_VFP_D_16_to_31 (&tmp_16_to_31); + } + } + return _UVRSR_OK; + + case _UVRSC_FPA: + return _UVRSR_NOT_IMPLEMENTED; + + case _UVRSC_WMMXD: + { + _uw start = discriminator >> 16; + _uw count = discriminator & 0xffff; + struct wmmxd_regs tmp; + _uw *sp; + _uw *dest; + + if ((representation != _UVRSD_UINT64) || start + count > 16) + return _UVRSR_FAILED; + + if (vrs->demand_save_flags & DEMAND_SAVE_WMMXD) + { + /* Demand-save resisters for stage1. */ + vrs->demand_save_flags &= ~DEMAND_SAVE_WMMXD; + __gnu_Unwind_Save_WMMXD (&vrs->wmmxd); + } + + /* Restore the registers from the stack. Do this by saving the + current WMMXD registers to a memory area, moving the in-memory + values into that area, and restoring from the whole area. */ + __gnu_Unwind_Save_WMMXD (&tmp); + + /* The stack address is only guaranteed to be word aligned, so + we can't use doubleword copies. */ + sp = (_uw *) vrs->core.r[R_SP]; + dest = (_uw *) &tmp.wd[start]; + count *= 2; + while (count--) + *(dest++) = *(sp++); + + /* Set the new stack pointer. */ + vrs->core.r[R_SP] = (_uw) sp; + + /* Reload the registers. */ + __gnu_Unwind_Restore_WMMXD (&tmp); + } + return _UVRSR_OK; + + case _UVRSC_WMMXC: + { + int i; + struct wmmxc_regs tmp; + _uw *sp; + + if ((representation != _UVRSD_UINT32) || discriminator > 16) + return _UVRSR_FAILED; + + if (vrs->demand_save_flags & DEMAND_SAVE_WMMXC) + { + /* Demand-save resisters for stage1. */ + vrs->demand_save_flags &= ~DEMAND_SAVE_WMMXC; + __gnu_Unwind_Save_WMMXC (&vrs->wmmxc); + } + + /* Restore the registers from the stack. Do this by saving the + current WMMXC registers to a memory area, moving the in-memory + values into that area, and restoring from the whole area. */ + __gnu_Unwind_Save_WMMXC (&tmp); + + sp = (_uw *) vrs->core.r[R_SP]; + for (i = 0; i < 4; i++) + if (discriminator & (1 << i)) + tmp.wc[i] = *(sp++); + + /* Set the new stack pointer. */ + vrs->core.r[R_SP] = (_uw) sp; + + /* Reload the registers. */ + __gnu_Unwind_Restore_WMMXC (&tmp); + } + return _UVRSR_OK; + + default: + return _UVRSR_FAILED; + } +} + + +/* Core unwinding functions. */ + +/* Calculate the address encoded by a 31-bit self-relative offset at address + P. */ +static inline _uw +selfrel_offset31 (const _uw *p) +{ + _uw offset; + + offset = *p; + /* Sign extend to 32 bits. */ + if (offset & (1 << 30)) + offset |= 1u << 31; + else + offset &= ~(1u << 31); + + return offset + (_uw) p; +} + + +/* Perform a binary search for RETURN_ADDRESS in TABLE. The table contains + NREC entries. */ + +static const __EIT_entry * +search_EIT_table (const __EIT_entry * table, int nrec, _uw return_address) +{ + _uw next_fn; + _uw this_fn; + int n, left, right; + + if (nrec == 0) + return (__EIT_entry *) 0; + + left = 0; + right = nrec - 1; + + while (1) + { + n = (left + right) / 2; + this_fn = selfrel_offset31 (&table[n].fnoffset); + if (n != nrec - 1) + next_fn = selfrel_offset31 (&table[n + 1].fnoffset) - 1; + else + next_fn = (_uw)0 - 1; + + if (return_address < this_fn) + { + if (n == left) + return (__EIT_entry *) 0; + right = n - 1; + } + else if (return_address <= next_fn) + return &table[n]; + else + left = n + 1; + } +} + +/* Find the exception index table eintry for the given address. + Fill in the relevant fields of the UCB. + Returns _URC_FAILURE if an error occurred, _URC_OK on success. */ + +static _Unwind_Reason_Code +get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address) +{ + const __EIT_entry * eitp; + int nrec; + + /* The return address is the address of the instruction following the + call instruction (plus one in thumb mode). If this was the last + instruction in the function the address will lie in the following + function. Subtract 2 from the address so that it points within the call + instruction itself. */ + return_address -= 2; + + if (__gnu_Unwind_Find_exidx) + { + eitp = (const __EIT_entry *) __gnu_Unwind_Find_exidx (return_address, + &nrec); + if (!eitp) + { + UCB_PR_ADDR (ucbp) = 0; + return _URC_FAILURE; + } + } + else + { + eitp = &__exidx_start; + nrec = &__exidx_end - &__exidx_start; + } + + eitp = search_EIT_table (eitp, nrec, return_address); + + if (!eitp) + { + UCB_PR_ADDR (ucbp) = 0; + return _URC_FAILURE; + } + ucbp->pr_cache.fnstart = selfrel_offset31 (&eitp->fnoffset); + + /* Can this frame be unwound at all? */ + if (eitp->content == EXIDX_CANTUNWIND) + { + UCB_PR_ADDR (ucbp) = 0; + return _URC_END_OF_STACK; + } + + /* Obtain the address of the "real" __EHT_Header word. */ + + if (eitp->content & uint32_highbit) + { + /* It is immediate data. */ + ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content; + ucbp->pr_cache.additional = 1; + } + else + { + /* The low 31 bits of the content field are a self-relative + offset to an _Unwind_EHT_Entry structure. */ + ucbp->pr_cache.ehtp = + (_Unwind_EHT_Header *) selfrel_offset31 (&eitp->content); + ucbp->pr_cache.additional = 0; + } + + /* Discover the personality routine address. */ + if (*ucbp->pr_cache.ehtp & (1u << 31)) + { + /* One of the predefined standard routines. */ + _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf; + if (idx == 0) + UCB_PR_ADDR (ucbp) = (_uw) &__aeabi_unwind_cpp_pr0; + else if (idx == 1) + UCB_PR_ADDR (ucbp) = (_uw) &__aeabi_unwind_cpp_pr1; + else if (idx == 2) + UCB_PR_ADDR (ucbp) = (_uw) &__aeabi_unwind_cpp_pr2; + else + { /* Failed */ + UCB_PR_ADDR (ucbp) = 0; + return _URC_FAILURE; + } + } + else + { + /* Execute region offset to PR */ + UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp); + } + return _URC_OK; +} + + +/* Perform phase2 unwinding. VRS is the initial virtual register state. */ + +static void __attribute__((noreturn)) +unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs) +{ + _Unwind_Reason_Code pr_result; + + do + { + /* Find the entry for this routine. */ + if (get_eit_entry (ucbp, vrs->core.r[R_PC]) != _URC_OK) + abort (); + + UCB_SAVED_CALLSITE_ADDR (ucbp) = vrs->core.r[R_PC]; + + /* Call the pr to decide what to do. */ + pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) + (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs); + } + while (pr_result == _URC_CONTINUE_UNWIND); + + if (pr_result != _URC_INSTALL_CONTEXT) + abort(); + + restore_core_regs (&vrs->core); +} + +/* Perform phase2 forced unwinding. */ + +static _Unwind_Reason_Code +unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs, + int resuming) +{ + _Unwind_Stop_Fn stop_fn = (_Unwind_Stop_Fn) UCB_FORCED_STOP_FN (ucbp); + void *stop_arg = (void *)UCB_FORCED_STOP_ARG (ucbp); + _Unwind_Reason_Code pr_result = 0; + /* We use phase1_vrs here even though we do not demand save, for the + prev_sp field. */ + phase1_vrs saved_vrs, next_vrs; + + /* Save the core registers. */ + saved_vrs.core = entry_vrs->core; + /* We don't need to demand-save the non-core registers, because we + unwind in a single pass. */ + saved_vrs.demand_save_flags = 0; + + /* Unwind until we reach a propagation barrier. */ + do + { + _Unwind_State action; + _Unwind_Reason_Code entry_code; + _Unwind_Reason_Code stop_code; + + /* Find the entry for this routine. */ + entry_code = get_eit_entry (ucbp, saved_vrs.core.r[R_PC]); + + if (resuming) + { + action = _US_UNWIND_FRAME_RESUME | _US_FORCE_UNWIND; + resuming = 0; + } + else + action = _US_UNWIND_FRAME_STARTING | _US_FORCE_UNWIND; + + if (entry_code == _URC_OK) + { + UCB_SAVED_CALLSITE_ADDR (ucbp) = saved_vrs.core.r[R_PC]; + + next_vrs = saved_vrs; + + /* Call the pr to decide what to do. */ + pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) + (action, ucbp, (void *) &next_vrs); + + saved_vrs.prev_sp = next_vrs.core.r[R_SP]; + } + else + { + /* Treat any failure as the end of unwinding, to cope more + gracefully with missing EH information. Mixed EH and + non-EH within one object will usually result in failure, + because the .ARM.exidx tables do not indicate the end + of the code to which they apply; but mixed EH and non-EH + shared objects should return an unwind failure at the + entry of a non-EH shared object. */ + action |= _US_END_OF_STACK; + + saved_vrs.prev_sp = saved_vrs.core.r[R_SP]; + } + + stop_code = stop_fn (1, action, ucbp->exception_class, ucbp, + (void *)&saved_vrs, stop_arg); + if (stop_code != _URC_NO_REASON) + return _URC_FAILURE; + + if (entry_code != _URC_OK) + return entry_code; + + saved_vrs = next_vrs; + } + while (pr_result == _URC_CONTINUE_UNWIND); + + if (pr_result != _URC_INSTALL_CONTEXT) + { + /* Some sort of failure has occurred in the pr and probably the + pr returned _URC_FAILURE. */ + return _URC_FAILURE; + } + + restore_core_regs (&saved_vrs.core); +} + +/* This is a very limited implementation of _Unwind_GetCFA. It returns + the stack pointer as it is about to be unwound, and is only valid + while calling the stop function during forced unwinding. If the + current personality routine result is going to run a cleanup, this + will not be the CFA; but when the frame is really unwound, it will + be. */ + +_Unwind_Word +_Unwind_GetCFA (_Unwind_Context *context) +{ + return ((phase1_vrs *) context)->prev_sp; +} + +/* Perform phase1 unwinding. UCBP is the exception being thrown, and + entry_VRS is the register state on entry to _Unwind_RaiseException. */ + +_Unwind_Reason_Code +__gnu_Unwind_RaiseException (_Unwind_Control_Block *, phase2_vrs *); + +_Unwind_Reason_Code +__gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp, + phase2_vrs * entry_vrs) +{ + phase1_vrs saved_vrs; + _Unwind_Reason_Code pr_result; + + /* Set the pc to the call site. */ + entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR]; + + /* Save the core registers. */ + saved_vrs.core = entry_vrs->core; + /* Set demand-save flags. */ + saved_vrs.demand_save_flags = ~(_uw) 0; + + /* Unwind until we reach a propagation barrier. */ + do + { + /* Find the entry for this routine. */ + if (get_eit_entry (ucbp, saved_vrs.core.r[R_PC]) != _URC_OK) + return _URC_FAILURE; + + /* Call the pr to decide what to do. */ + pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) + (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs); + } + while (pr_result == _URC_CONTINUE_UNWIND); + + /* We've unwound as far as we want to go, so restore the original + register state. */ + restore_non_core_regs (&saved_vrs); + if (pr_result != _URC_HANDLER_FOUND) + { + /* Some sort of failure has occurred in the pr and probably the + pr returned _URC_FAILURE. */ + return _URC_FAILURE; + } + + unwind_phase2 (ucbp, entry_vrs); +} + +/* Resume unwinding after a cleanup has been run. UCBP is the exception + being thrown and ENTRY_VRS is the register state on entry to + _Unwind_Resume. */ +_Unwind_Reason_Code +__gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *, + _Unwind_Stop_Fn, void *, phase2_vrs *); + +_Unwind_Reason_Code +__gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *ucbp, + _Unwind_Stop_Fn stop_fn, void *stop_arg, + phase2_vrs *entry_vrs) +{ + UCB_FORCED_STOP_FN (ucbp) = (_uw) stop_fn; + UCB_FORCED_STOP_ARG (ucbp) = (_uw) stop_arg; + + /* Set the pc to the call site. */ + entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR]; + + return unwind_phase2_forced (ucbp, entry_vrs, 0); +} + +_Unwind_Reason_Code +__gnu_Unwind_Resume (_Unwind_Control_Block *, phase2_vrs *); + +_Unwind_Reason_Code +__gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs) +{ + _Unwind_Reason_Code pr_result; + + /* Recover the saved address. */ + entry_vrs->core.r[R_PC] = UCB_SAVED_CALLSITE_ADDR (ucbp); + + if (UCB_FORCED_STOP_FN (ucbp)) + { + unwind_phase2_forced (ucbp, entry_vrs, 1); + + /* We can't return failure at this point. */ + abort (); + } + + /* Call the cached PR. */ + pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) + (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs); + + switch (pr_result) + { + case _URC_INSTALL_CONTEXT: + /* Upload the registers to enter the landing pad. */ + restore_core_regs (&entry_vrs->core); + + case _URC_CONTINUE_UNWIND: + /* Continue unwinding the next frame. */ + unwind_phase2 (ucbp, entry_vrs); + + default: + abort (); + } +} + +_Unwind_Reason_Code +__gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block *, phase2_vrs *); + +_Unwind_Reason_Code +__gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block * ucbp, + phase2_vrs * entry_vrs) +{ + if (!UCB_FORCED_STOP_FN (ucbp)) + return __gnu_Unwind_RaiseException (ucbp, entry_vrs); + + /* Set the pc to the call site. */ + entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR]; + /* Continue unwinding the next frame. */ + return unwind_phase2_forced (ucbp, entry_vrs, 0); +} + +/* Clean up an exception object when unwinding is complete. */ +void +_Unwind_Complete (_Unwind_Control_Block * ucbp __attribute__((unused))) +{ +} + + +/* Get the _Unwind_Control_Block from an _Unwind_Context. */ + +static inline _Unwind_Control_Block * +unwind_UCB_from_context (_Unwind_Context * context) +{ + return (_Unwind_Control_Block *) _Unwind_GetGR (context, R_IP); +} + + +/* Free an exception. */ + +void +_Unwind_DeleteException (_Unwind_Exception * exc) +{ + if (exc->exception_cleanup) + (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc); +} + + +/* Perform stack backtrace through unwind data. */ +_Unwind_Reason_Code +__gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument, + phase2_vrs * entry_vrs); +_Unwind_Reason_Code +__gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument, + phase2_vrs * entry_vrs) +{ + phase1_vrs saved_vrs; + _Unwind_Reason_Code code; + + _Unwind_Control_Block ucb; + _Unwind_Control_Block *ucbp = &ucb; + + /* Set the pc to the call site. */ + entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR]; + + /* Save the core registers. */ + saved_vrs.core = entry_vrs->core; + /* Set demand-save flags. */ + saved_vrs.demand_save_flags = ~(_uw) 0; + + do + { + /* Find the entry for this routine. */ + if (get_eit_entry (ucbp, saved_vrs.core.r[R_PC]) != _URC_OK) + { + code = _URC_FAILURE; + break; + } + + /* The dwarf unwinder assumes the context structure holds things + like the function and LSDA pointers. The ARM implementation + caches these in the exception header (UCB). To avoid + rewriting everything we make the virtual IP register point at + the UCB. */ + _Unwind_SetGR((_Unwind_Context *)&saved_vrs, 12, (_Unwind_Ptr) ucbp); + + /* Call trace function. */ + if ((*trace) ((_Unwind_Context *) &saved_vrs, trace_argument) + != _URC_NO_REASON) + { + code = _URC_FAILURE; + break; + } + + /* Call the pr to decide what to do. */ + code = ((personality_routine) UCB_PR_ADDR (ucbp)) + (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, + ucbp, (void *) &saved_vrs); + } + while (code != _URC_END_OF_STACK + && code != _URC_FAILURE); + + restore_non_core_regs (&saved_vrs); + return code; +} + + +/* Common implementation for ARM ABI defined personality routines. + ID is the index of the personality routine, other arguments are as defined + by __aeabi_unwind_cpp_pr{0,1,2}. */ + +static _Unwind_Reason_Code +__gnu_unwind_pr_common (_Unwind_State state, + _Unwind_Control_Block *ucbp, + _Unwind_Context *context, + int id) +{ + __gnu_unwind_state uws; + _uw *data; + _uw offset; + _uw len; + _uw rtti_count; + int phase2_call_unexpected_after_unwind = 0; + int in_range = 0; + int forced_unwind = state & _US_FORCE_UNWIND; + + state &= _US_ACTION_MASK; + + data = (_uw *) ucbp->pr_cache.ehtp; + uws.data = *(data++); + uws.next = data; + if (id == 0) + { + uws.data <<= 8; + uws.words_left = 0; + uws.bytes_left = 3; + } + else + { + uws.words_left = (uws.data >> 16) & 0xff; + uws.data <<= 16; + uws.bytes_left = 2; + data += uws.words_left; + } + + /* Restore the saved pointer. */ + if (state == _US_UNWIND_FRAME_RESUME) + data = (_uw *) ucbp->cleanup_cache.bitpattern[0]; + + if ((ucbp->pr_cache.additional & 1) == 0) + { + /* Process descriptors. */ + while (*data) + { + _uw addr; + _uw fnstart; + + if (id == 2) + { + len = ((EHT32 *) data)->length; + offset = ((EHT32 *) data)->offset; + data += 2; + } + else + { + len = ((EHT16 *) data)->length; + offset = ((EHT16 *) data)->offset; + data++; + } + + fnstart = ucbp->pr_cache.fnstart + (offset & ~1); + addr = _Unwind_GetGR (context, R_PC); + in_range = (fnstart <= addr && addr < fnstart + (len & ~1)); + + switch (((offset & 1) << 1) | (len & 1)) + { + case 0: + /* Cleanup. */ + if (state != _US_VIRTUAL_UNWIND_FRAME + && in_range) + { + /* Cleanup in range, and we are running cleanups. */ + _uw lp; + + /* Landing pad address is 31-bit pc-relative offset. */ + lp = selfrel_offset31 (data); + data++; + /* Save the exception data pointer. */ + ucbp->cleanup_cache.bitpattern[0] = (_uw) data; + if (!__cxa_begin_cleanup (ucbp)) + return _URC_FAILURE; + /* Setup the VRS to enter the landing pad. */ + _Unwind_SetGR (context, R_PC, lp); + return _URC_INSTALL_CONTEXT; + } + /* Cleanup not in range, or we are in stage 1. */ + data++; + break; + + case 1: + /* Catch handler. */ + if (state == _US_VIRTUAL_UNWIND_FRAME) + { + if (in_range) + { + /* Check for a barrier. */ + _uw rtti; + bool is_reference = (data[0] & uint32_highbit) != 0; + void *matched; + enum __cxa_type_match_result match_type; + + /* Check for no-throw areas. */ + if (data[1] == (_uw) -2) + return _URC_FAILURE; + + /* The thrown object immediately follows the ECB. */ + matched = (void *)(ucbp + 1); + if (data[1] != (_uw) -1) + { + /* Match a catch specification. */ + rtti = _Unwind_decode_target2 ((_uw) &data[1]); + match_type = __cxa_type_match (ucbp, + (type_info *) rtti, + is_reference, + &matched); + } + else + match_type = ctm_succeeded; + + if (match_type) + { + ucbp->barrier_cache.sp = + _Unwind_GetGR (context, R_SP); + // ctm_succeeded_with_ptr_to_base really + // means _c_t_m indirected the pointer + // object. We have to reconstruct the + // additional pointer layer by using a temporary. + if (match_type == ctm_succeeded_with_ptr_to_base) + { + ucbp->barrier_cache.bitpattern[2] + = (_uw) matched; + ucbp->barrier_cache.bitpattern[0] + = (_uw) &ucbp->barrier_cache.bitpattern[2]; + } + else + ucbp->barrier_cache.bitpattern[0] = (_uw) matched; + ucbp->barrier_cache.bitpattern[1] = (_uw) data; + return _URC_HANDLER_FOUND; + } + } + /* Handler out of range, or not matched. */ + } + else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP) + && ucbp->barrier_cache.bitpattern[1] == (_uw) data) + { + /* Matched a previous propagation barrier. */ + _uw lp; + + /* Setup for entry to the handler. */ + lp = selfrel_offset31 (data); + _Unwind_SetGR (context, R_PC, lp); + _Unwind_SetGR (context, 0, (_uw) ucbp); + return _URC_INSTALL_CONTEXT; + } + /* Catch handler not matched. Advance to the next descriptor. */ + data += 2; + break; + + case 2: + rtti_count = data[0] & 0x7fffffff; + /* Exception specification. */ + if (state == _US_VIRTUAL_UNWIND_FRAME) + { + if (in_range && (!forced_unwind || !rtti_count)) + { + /* Match against the exception specification. */ + _uw i; + _uw rtti; + void *matched; + + for (i = 0; i < rtti_count; i++) + { + matched = (void *)(ucbp + 1); + rtti = _Unwind_decode_target2 ((_uw) &data[i + 1]); + if (__cxa_type_match (ucbp, (type_info *) rtti, 0, + &matched)) + break; + } + + if (i == rtti_count) + { + /* Exception does not match the spec. */ + ucbp->barrier_cache.sp = + _Unwind_GetGR (context, R_SP); + ucbp->barrier_cache.bitpattern[0] = (_uw) matched; + ucbp->barrier_cache.bitpattern[1] = (_uw) data; + return _URC_HANDLER_FOUND; + } + } + /* Handler out of range, or exception is permitted. */ + } + else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP) + && ucbp->barrier_cache.bitpattern[1] == (_uw) data) + { + /* Matched a previous propagation barrier. */ + _uw lp; + /* Record the RTTI list for __cxa_call_unexpected. */ + ucbp->barrier_cache.bitpattern[1] = rtti_count; + ucbp->barrier_cache.bitpattern[2] = 0; + ucbp->barrier_cache.bitpattern[3] = 4; + ucbp->barrier_cache.bitpattern[4] = (_uw) &data[1]; + + if (data[0] & uint32_highbit) + { + data += rtti_count + 1; + /* Setup for entry to the handler. */ + lp = selfrel_offset31 (data); + data++; + _Unwind_SetGR (context, R_PC, lp); + _Unwind_SetGR (context, 0, (_uw) ucbp); + return _URC_INSTALL_CONTEXT; + } + else + phase2_call_unexpected_after_unwind = 1; + } + if (data[0] & uint32_highbit) + data++; + data += rtti_count + 1; + break; + + default: + /* Should never happen. */ + return _URC_FAILURE; + } + /* Finished processing this descriptor. */ + } + } + + if (__gnu_unwind_execute (context, &uws) != _URC_OK) + return _URC_FAILURE; + + if (phase2_call_unexpected_after_unwind) + { + /* Enter __cxa_unexpected as if called from the call site. */ + _Unwind_SetGR (context, R_LR, _Unwind_GetGR (context, R_PC)); + _Unwind_SetGR (context, R_PC, (_uw) &__cxa_call_unexpected); + return _URC_INSTALL_CONTEXT; + } + + return _URC_CONTINUE_UNWIND; +} + + +/* ABI defined personality routine entry points. */ + +_Unwind_Reason_Code +__aeabi_unwind_cpp_pr0 (_Unwind_State state, + _Unwind_Control_Block *ucbp, + _Unwind_Context *context) +{ + return __gnu_unwind_pr_common (state, ucbp, context, 0); +} + +_Unwind_Reason_Code +__aeabi_unwind_cpp_pr1 (_Unwind_State state, + _Unwind_Control_Block *ucbp, + _Unwind_Context *context) +{ + return __gnu_unwind_pr_common (state, ucbp, context, 1); +} + +_Unwind_Reason_Code +__aeabi_unwind_cpp_pr2 (_Unwind_State state, + _Unwind_Control_Block *ucbp, + _Unwind_Context *context) +{ + return __gnu_unwind_pr_common (state, ucbp, context, 2); +} |