sl@0: /* unwinder.c
sl@0:  *
sl@0:  * Copyright 2002-2005 ARM Limited. All rights reserved.
sl@0:  *
sl@0:  * Your rights to use this code are set out in the accompanying licence
sl@0:  * text file LICENCE.txt (ARM contract number LEC-ELA-00080 v1.0).
sl@0:  */
sl@0: 
sl@0: /* Portions copyright Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). */
sl@0: 
sl@0: /*
sl@0:  * RCS $Revision: 92986 $
sl@0:  * Checkin $Date: 2005-10-13 15:56:12 +0100 (Thu, 13 Oct 2005) $
sl@0:  * Revising $Author: achapman $
sl@0:  */
sl@0: 
sl@0: /* Language-independent unwinder implementation */
sl@0: 
sl@0: /* This source file is compiled automatically by ARM's make system into
sl@0:  * multiple object files. The source regions constituting object file
sl@0:  * xxx.o are delimited by ifdef xxx_c / endif directives.
sl@0:  *
sl@0:  * The source regions currently marked are:
sl@0:  * unwinder_c
sl@0:  * unwind_activity_c
sl@0:  */
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0: #include <stddef.h>
sl@0: #include <stdlib.h>
sl@0: #else
sl@0: #include <e32def.h>
sl@0: #endif
sl@0: /* Environment: */
sl@0: #include "unwind_env.h"
sl@0: /* Language-independent unwinder declarations: */
sl@0: #include "unwinder.h"
sl@0: 
sl@0: #ifdef __EPOC32__
sl@0: /* Symbian specific support */
sl@0: #include "symbian_support.h"
sl@0: #endif
sl@0: 
sl@0: /* Define UNWIND_ACTIVITY_DIAGNOSTICS for printed information from _Unwind_Activity */
sl@0: /* Define VRS_DIAGNOSTICS for printed diagnostics about VRS operations */
sl@0: 
sl@0: #if defined(VRS_DIAGNOSTICS) || defined(UNWIND_ACTIVITY_DIAGNOSTICS)
sl@0: #ifndef __EPOC32__
sl@0: extern int printf(const char *, ...);
sl@0: #endif
sl@0: #endif
sl@0: 
sl@0: #ifdef SUPPORT_NESTED_EXCEPTIONS
sl@0: extern _Unwind_Control_Block *AllocSavedUCB();
sl@0: extern void FreeSavedUCB(_Unwind_Control_Block *context);
sl@0: #endif
sl@0: 
sl@0: #ifdef unwinder_c
sl@0: 
sl@0: /* =========================                      ========================= */
sl@0: /* ========================= Virtual register set ========================= */
sl@0: /* =========================                      ========================= */
sl@0: 
sl@0: /* The approach taken by this implementation is to use the real machine
sl@0:  * registers to hold all but the values of core (integer)
sl@0:  * registers. Consequently the implementation must use only the core
sl@0:  * registers except when manipulating the virtual register set. Non-core
sl@0:  * registers are saved only on first use, so the single implementation can
sl@0:  * cope with execution on processors which lack certain registers.  The
sl@0:  * registers as they were at the start of the propagation must be preserved
sl@0:  * over phase 1 so that the machine state is correct at the start of phase
sl@0:  * 2. This requires a copy to be taken (which can be stack allocated). During
sl@0:  * a stack unwind (phase 1 or phase 2), the "current" virtual register set is
sl@0:  * implemented as core register values held in a data structure, and non-core
sl@0:  * register values held in the registers themselves. To ensure that all
sl@0:  * original register values are available at the beginning of phase 2, the
sl@0:  * core registers are saved in a second structure at the start of phase 1 and
sl@0:  * the non-core registers are demand-saved into another part of the data
sl@0:  * structure that holds the current core registers during the phase 1 stack
sl@0:  * unwind.
sl@0:  */
sl@0: /* Extent to which the access routines are implemented:
sl@0:  * _Unwind_VRS_Get and _Unwind_VRS_Set implement only access to the core registers.
sl@0:  * _Unwind_VRS_Pop implements only popping of core and vfp registers.
sl@0:  * There is no support here for the Intel WMMX registers, but space is nevertheless
sl@0:  * reserved in the virtual register set structure to indicate whether demand-saving
sl@0:  * of those registers is required (as they are unsupported, it never is). The space
sl@0:  * costs nothing as it is required for alignment.
sl@0:  * The level of supported functionality is compliant with the requirements of the
sl@0:  * Exceptions ABI.
sl@0:  */
sl@0: 
sl@0: typedef unsigned char bool;
sl@0: struct core_s  { uint32_t r[16]; };        /* core integer regs */
sl@0: struct vfp_s   { uint64_t d[32]; };        /* VFP registers saved in FSTMD format */
sl@0: 
sl@0: /* Phase 1 virtual register set includes demand-save areas */
sl@0: /* The phase 2 virtual register set must be a prefix of the phase 1 set */
sl@0: typedef struct phase1_virtual_register_set_s {
sl@0:   /* demand_save flag == 1 means save the registers in the demand-save area */
sl@0:   bool demand_save_vfp_low;
sl@0:   bool demand_save_vfp_high;
sl@0:   bool demand_save_wmmxd;
sl@0:   bool demand_save_wmmxc;
sl@0:   struct core_s core;      /* current core registers */
sl@0:   struct vfp_s  vfp;       /* demand-saved vfp registers */
sl@0: } phase1_virtual_register_set;
sl@0: 
sl@0: /* Phase 2 virtual register set has no demand-save areas */
sl@0: /* The phase 2 virtual register set must be a prefix of the phase 1 set */
sl@0: /* The assembly fragments for _Unwind_RaiseException and _Unwind_Resume create
sl@0:  * a phase2_virtual_register_set_s by hand so be careful.
sl@0:  */
sl@0: typedef struct phase2_virtual_register_set_s {
sl@0:   /* demand_save flag == 1 means save the registers in the demand-save area */
sl@0:   /* Always 0 in phase 2 */
sl@0:   bool demand_save_vfp_low;
sl@0:   bool demand_save_vfp_high;
sl@0:   bool demand_save_wmmxd;
sl@0:   bool demand_save_wmmxc;
sl@0:   struct core_s core;      /* current core registers */
sl@0: } phase2_virtual_register_set;
sl@0: 
sl@0: /* -- Helper macros for the embedded assembly */
sl@0: 
sl@0: #if defined(__TARGET_ARCH_5T)  || defined(__TARGET_ARCH_5TXM) || \
sl@0:     defined(__TARGET_ARCH_5TE) || defined(__TARGET_ARCH_6) || \
sl@0:     defined(__TARGET_ARCH_6T2) || defined(__TARGET_ARCH_7_A) /* || ... */
sl@0:   #define ARCH_5T_OR_LATER 1
sl@0: #else
sl@0:   #define ARCH_5T_OR_LATER 0
sl@0: #endif
sl@0: 
sl@0: #if defined(__APCS_INTERWORK) && !ARCH_5T_OR_LATER
sl@0:   #define OLD_STYLE_INTERWORKING 1
sl@0: #else
sl@0:   #define OLD_STYLE_INTERWORKING 0
sl@0: #endif
sl@0: 
sl@0: #if defined(__TARGET_ARCH_4T) || defined(__TARGET_ARCH_4TXM) || ARCH_5T_OR_LATER
sl@0:   #define HAVE_BX 1
sl@0: #else
sl@0:   #define HAVE_BX 0
sl@0: #endif
sl@0: 
sl@0: #if defined(__TARGET_ARCH_THUMBNAIL)
sl@0:   #define THUMBNAIL 1
sl@0: #else
sl@0:   #define THUMBNAIL 0
sl@0: #endif
sl@0: 
sl@0: #if HAVE_BX
sl@0:   #define RET_LR bx lr
sl@0: #else
sl@0:   #define RET_LR mov pc,lr
sl@0: #endif
sl@0: 
sl@0: /* ----- Routines: ----- */
sl@0: 
sl@0: /* ----- Helper routines, private ----- */
sl@0: 
sl@0: /* R_ARM_PREL31 is a place-relative 31-bit signed relocation.  The
sl@0:  * routine takes the address of a location that was relocated by
sl@0:  * R_ARM_PREL31, and returns an absolute address.
sl@0:  */
sl@0: static FORCEINLINE uint32_t __ARM_resolve_prel31(void *p)
sl@0: {
sl@0:   return (uint32_t)((((*(int32_t *)p) << 1) >> 1) + (int32_t)p);
sl@0: }
sl@0: 
sl@0: /* ----- Helper routines, private but external ----- */
sl@0: 
sl@0: /* Note '%0' refers to local label '0' */
sl@0: #if defined(__thumb)
sl@0: #define MAYBE_SWITCH_TO_ARM_STATE SWITCH_TO_ARM_STATE
sl@0: #define MAYBE_CODE16 code16
sl@0: #else
sl@0: #define MAYBE_SWITCH_TO_ARM_STATE /* nothing */
sl@0: #define MAYBE_CODE16              /* nothing */
sl@0: #endif
sl@0: __asm void __ARM_Unwind_VRS_VFPpreserve_low(void *vfpp)
sl@0: {
sl@0: vfp_d0 CN 0;
sl@0:   /* Preserve the low vfp registers in the passed memory */
sl@0: #if defined(__thumb)
sl@0:   macro;
sl@0:   SWITCH_TO_ARM_STATE;
sl@0: 1
sl@0:   align 4;
sl@0: 2
sl@0:   assert (%2 - %1) = 0;
sl@0:   bx pc;
sl@0:   nop;
sl@0:   code32;
sl@0:   mend;
sl@0: #endif
sl@0: 
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0:   stc   p11,vfp_d0,[r0],{0x20};  /* 0xec800b20  FSTMIAD r0,{d0-d15} */
sl@0:   RET_LR;
sl@0:   MAYBE_CODE16;
sl@0: }
sl@0: 
sl@0: __asm void __ARM_Unwind_VRS_VFPpreserve_high(void *vfpp)
sl@0: {
sl@0: vfp_d16 CN 0;                      /* =16 when used with stcl */
sl@0:   /* Preserve the high vfp registers in the passed memory */
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0:   stcl  p11,vfp_d16,[r0],{0x20};  /* 0xecc00b20  FSTMIAD r0,{d16-d31} */
sl@0:   RET_LR;
sl@0:   MAYBE_CODE16;
sl@0: }
sl@0: 
sl@0: __asm void __ARM_Unwind_VRS_VFPrestore_low(void *vfpp)
sl@0: {
sl@0:   /* Restore the low vfp registers from the passed memory */
sl@0: vfp_d0 CN 0;
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0:   ldc   p11,vfp_d0,[r0],{0x20};  /* 0xec900b20  FLDMIAD r0,{d0-d15} */
sl@0:   RET_LR;
sl@0:   MAYBE_CODE16;
sl@0: }
sl@0: 
sl@0: __asm void __ARM_Unwind_VRS_VFPrestore_high(void *vfpp)
sl@0: {
sl@0:   /* Restore the high vfp registers from the passed memory */
sl@0: vfp_d16 CN 0;                      /* =16 when used with ldcl */
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0:   ldcl   p11,vfp_d16,[r0],{0x20};  /* 0xecd00b20  FLDMIAD r0,{d16-d31} */
sl@0:   RET_LR;
sl@0:   MAYBE_CODE16;
sl@0: }
sl@0: 
sl@0: 
sl@0: __asm NORETURNDECL void __ARM_Unwind_VRS_corerestore(void *corep)
sl@0: {
sl@0:   /* We rely here on corep pointing to a location in the stack,
sl@0:    * as we briefly assign it to sp. This allows us to safely do
sl@0:    * ldmia's which restore sp (if we use a different base register,
sl@0:    * the updated sp may be used by the handler of any data abort
sl@0:    * that occurs during the ldmia, and the stack gets overwritten).
sl@0:    * By hypothesis this is preserve8 but the load of sp means the
sl@0:    * assembler can't infer that.
sl@0:    */
sl@0: #if THUMBNAIL
sl@0:   preserve8;
sl@0:   mov.w   r13, r0;
sl@0:   ldmia.w r13!,{r0-r12};
sl@0:   ldr.w   r14, [r13, #4]   /* lr */
sl@0:   ldr.w   r12, [r13, #4*2] /* pc */
sl@0:   ldr.w   r13, [r13, #0]   /* sp */
sl@0:   bx      r12
sl@0:   
sl@0: #else
sl@0:   preserve8;
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0: #if OLD_STYLE_INTERWORKING
sl@0:   mov   r13, r0;
sl@0:   ldmia r13!,{r0-r12};
sl@0:   ldr   r12,[r13, #4*2]; /* pc */
sl@0:   ldmia r13,{r13-r14};
sl@0:   bx    r12;
sl@0: #else
sl@0: 
sl@0:   #if __ARMCC_VERSION < 300000
sl@0:   mov   r13, r0;
sl@0:   ldmia r13,{r0-r15};
sl@0:   #else
sl@0:   mov r14, r0;
sl@0:   ldmia r14!, {r0-r12};
sl@0:   ldr r13, [r14], #4;
sl@0:   ldmia r14, {r14,r15};
sl@0:   #endif
sl@0: 
sl@0: #endif
sl@0:   MAYBE_CODE16;
sl@0: #endif
sl@0: }
sl@0: 
sl@0: 
sl@0: /* ----- Development support ----- */
sl@0: 
sl@0: #ifdef VRS_DIAGNOSTICS
sl@0: static void debug_print_vrs_vfp(uint32_t base, uint64_t *lp)
sl@0: {
sl@0:   int c = 0;
sl@0:   int i;
sl@0:   for (i = 0; i < 16; i++) {
sl@0:     printf("D%-2d  0x%16.16llx    ", i + base, *lp);
sl@0:     lp++;
sl@0:     if (c++ == 1) {
sl@0:       c = 0;
sl@0:       printf("\n");
sl@0:     }
sl@0:   }
sl@0: }
sl@0: 
sl@0: 
sl@0: static void debug_print_vrs(_Unwind_Context *context)
sl@0: {
sl@0:   phase1_virtual_register_set *vrsp = (phase1_virtual_register_set *)context;
sl@0:   int i;
sl@0:   int c;
sl@0:   printf("------------------------------------------------------------------------\n");
sl@0:   c = 0;
sl@0:   for (i = 0; i < 16; i++) {
sl@0:     printf("r%-2d  0x%8.8x    ", i, vrsp->core.r[i]);
sl@0:     if (c++ == 3) {
sl@0:       c = 0;
sl@0:       printf("\n");
sl@0:     }
sl@0:   }
sl@0: 
sl@0:   printf("-----\n");
sl@0:   if (vrsp->demand_save_vfp_low == 1)
sl@0:     printf("VFP low registers not saved\n");
sl@0:   else
sl@0:     debug_print_vrs_vfp(0, &vrsp->vfp.d[0]);
sl@0:   printf("-----\n");
sl@0:   if (vrsp->demand_save_vfp_high == 1)
sl@0:     printf("VFP high registers not saved\n");
sl@0:   else
sl@0:     debug_print_vrs_vfp(16, &vrsp->vfp.d[16]);
sl@0:   printf("------------------------------------------------------------------------\n");
sl@0: }
sl@0: #endif
sl@0: 
sl@0: 
sl@0: /* ----- Public routines ----- */
sl@0: 
sl@0: EXPORT_C _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context,
sl@0:                                             _Unwind_VRS_RegClass regclass,
sl@0:                                             uint32_t regno,
sl@0:                                             _Unwind_VRS_DataRepresentation representation,
sl@0:                                             void *valuep)
sl@0: {
sl@0:   phase1_virtual_register_set *vrsp = (phase1_virtual_register_set *)context;
sl@0:   switch (regclass) {
sl@0:   case _UVRSC_CORE:
sl@0:     {
sl@0:       if (representation != _UVRSD_UINT32 || regno > 15)
sl@0:         return _UVRSR_FAILED;
sl@0:        vrsp->core.r[regno] = *(uint32_t *)valuep;
sl@0:        return _UVRSR_OK;
sl@0:     }
sl@0:   case _UVRSC_VFP:
sl@0:   case _UVRSC_WMMXD:
sl@0:   case _UVRSC_WMMXC:
sl@0:     return _UVRSR_NOT_IMPLEMENTED;
sl@0:   default:
sl@0:     break;
sl@0:   }
sl@0:   return _UVRSR_FAILED;
sl@0: }
sl@0: 
sl@0: 
sl@0: EXPORT_C _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context,
sl@0:                                             _Unwind_VRS_RegClass regclass,
sl@0:                                             uint32_t regno,
sl@0:                                             _Unwind_VRS_DataRepresentation representation,
sl@0:                                             void *valuep)
sl@0: {
sl@0:   phase1_virtual_register_set *vrsp = (phase1_virtual_register_set *)context;
sl@0:   switch (regclass) {
sl@0:   case _UVRSC_CORE:
sl@0:     {
sl@0:       if (representation != _UVRSD_UINT32 || regno > 15)
sl@0:         return _UVRSR_FAILED;
sl@0:       *(uint32_t *)valuep = vrsp->core.r[regno];
sl@0:       return _UVRSR_OK;
sl@0:     }
sl@0:   case _UVRSC_VFP:
sl@0:   case _UVRSC_WMMXD:
sl@0:   case _UVRSC_WMMXC:
sl@0:     return _UVRSR_NOT_IMPLEMENTED;
sl@0:   default:
sl@0:     break;
sl@0:   }
sl@0:   return _UVRSR_FAILED;
sl@0: }
sl@0: 
sl@0: 
sl@0: #define R_SP 13
sl@0: 
sl@0: EXPORT_C _Unwind_VRS_Result _Unwind_VRS_Pop(_Unwind_Context *context,
sl@0:                                             _Unwind_VRS_RegClass regclass,
sl@0:                                             uint32_t descriminator,
sl@0:                                             _Unwind_VRS_DataRepresentation representation)
sl@0: {
sl@0:   phase1_virtual_register_set *vrsp = (phase1_virtual_register_set *)context;
sl@0:   switch (regclass) {
sl@0:   case _UVRSC_CORE:
sl@0:     {
sl@0:       /* If SP is included in the mask, the loaded value is used in preference to
sl@0:        * the writeback value, but only on completion of the loading.
sl@0:        */
sl@0:       uint32_t mask, *vsp, *rp, sp_loaded;
sl@0:       if (representation != _UVRSD_UINT32)
sl@0:         return _UVRSR_FAILED;
sl@0:       vsp = (uint32_t *)vrsp->core.r[R_SP];
sl@0:       rp = (uint32_t *)&vrsp->core;
sl@0:       mask = descriminator & 0xffff;
sl@0:       sp_loaded = mask & (1 << R_SP);
sl@0:       while (mask != 0) {
sl@0:         if (mask & 1) {
sl@0: #ifdef VRS_DIAGNOSTICS
sl@0:           printf("VRS Pop r%d\n", rp - &vrsp->core.r[0]);
sl@0: #endif
sl@0:           *rp = *vsp++;
sl@0:         }
sl@0:         rp++;
sl@0:         mask >>= 1;
sl@0:       }
sl@0:       if (!sp_loaded)
sl@0:         vrsp->core.r[R_SP] = (uint32_t)vsp;
sl@0:       return _UVRSR_OK;
sl@0:     }
sl@0:   case _UVRSC_VFP:
sl@0:     {
sl@0:       uint32_t start = descriminator >> 16;
sl@0:       uint32_t count = descriminator & 0xffff;
sl@0:       bool some_low = start < 16;
sl@0:       bool some_high = start + count > 16;
sl@0:       if ((representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE) ||
sl@0:           (representation == _UVRSD_VFPX && some_high) ||
sl@0:           (representation == _UVRSD_DOUBLE && start + count > 32))
sl@0:         return _UVRSR_FAILED;
sl@0:       if (some_low && vrsp->demand_save_vfp_low == 1) { /* Demand-save over phase 1 */
sl@0:         vrsp->demand_save_vfp_low = 0;
sl@0:         __ARM_Unwind_VRS_VFPpreserve_low(&vrsp->vfp.d[0]);
sl@0:       }
sl@0:       if (some_high && vrsp->demand_save_vfp_high == 1) { /* Demand-save over phase 1 */
sl@0:         vrsp->demand_save_vfp_high = 0;
sl@0:         __ARM_Unwind_VRS_VFPpreserve_high(&vrsp->vfp.d[16]);
sl@0:       }
sl@0:       /* Now recover from the stack into the real machine registers.
sl@0:        * Note for _UVRSD_VFPX we assume FSTMX standard format 1.
sl@0:        * Do this by saving the current VFP registers to a memory area,
sl@0:        * moving the in-memory values into that area, and
sl@0:        * restoring from the whole area.
sl@0:        * Must be careful as the 64-bit values saved by FSTMX might be
sl@0:        * only 32-bit aligned.
sl@0:        */
sl@0:       {
sl@0:         struct unaligned_vfp_reg_s { uint32_t w1; uint32_t w2; };
sl@0:         struct unaligned_vfp_reg_s *vsp;
sl@0:         struct vfp_s temp_vfp;
sl@0:         if (some_low)
sl@0:           __ARM_Unwind_VRS_VFPpreserve_low(&temp_vfp.d[0]);
sl@0:         if (some_high)
sl@0:           __ARM_Unwind_VRS_VFPpreserve_high(&temp_vfp.d[16]);
sl@0:         vsp = (struct unaligned_vfp_reg_s *)vrsp->core.r[R_SP];
sl@0:         while (count--) {
sl@0:           struct unaligned_vfp_reg_s *v =
sl@0:             (struct unaligned_vfp_reg_s *)&temp_vfp.d[start++];
sl@0:           *v = *vsp++;
sl@0: #ifdef VRS_DIAGNOSTICS
sl@0:           printf("VRS Pop D%d = 0x%llx\n", start - 1, temp_vfp.d[start - 1]);
sl@0: #endif
sl@0:         }
sl@0:         vrsp->core.r[R_SP] = (uint32_t)((uint32_t *)vsp +
sl@0:                                         (representation == _UVRSD_VFPX ?
sl@0:                                          1 : /* +1 to skip the format word */
sl@0:                                          0));
sl@0:         if (some_low)
sl@0:           __ARM_Unwind_VRS_VFPrestore_low(&temp_vfp.d[0]);
sl@0:         if (some_high)
sl@0:           __ARM_Unwind_VRS_VFPrestore_high(&temp_vfp.d[16]);
sl@0:       }
sl@0:       return _UVRSR_OK;
sl@0:     }
sl@0:   case _UVRSC_WMMXD:
sl@0:   case _UVRSC_WMMXC:
sl@0:     return _UVRSR_NOT_IMPLEMENTED;
sl@0:   default:
sl@0:     break;
sl@0:   }
sl@0:   return _UVRSR_FAILED;
sl@0: }
sl@0: 
sl@0: 
sl@0: 
sl@0: /* =========================              ========================= */
sl@0: /* ========================= The unwinder ========================= */
sl@0: /* =========================              ========================= */
sl@0: 
sl@0: 
sl@0: /* This implementation uses the UCB unwinder_cache as follows:
sl@0:  * reserved1 is documented in the EABI as requiring initialisation to 0.
sl@0:  *  It is used to manage nested simultaneous propagation. If the value is 0,
sl@0:  *  the UCB is participating in no propagations. If the value is 1, the UCB
sl@0:  *  is participating in one propagation. Otherwise the value is a pointer to
sl@0:  *  a structure holding saved UCB state from the next propagation out.
sl@0:  *  The structure used is simply a mallocated UCB.
sl@0:  * reserved2 is used to preserve the call-site address over calls to a
sl@0:  *  personality routine and cleanup.
sl@0:  * reserved3 is used to cache the PR address.
sl@0:  * reserved4 is used by the Symbian implementation to cache the ROM exeception 
sl@0:  *  search table
sl@0:  * reserved5 is used by the symbian implementation to cache the 
sl@0:  *  TExceptionDescriptor for the executable of the 'current' frame
sl@0:  */
sl@0: 
sl@0: #define NESTED_CONTEXT      unwinder_cache.reserved1
sl@0: #define SAVED_CALLSITE_ADDR unwinder_cache.reserved2
sl@0: #define PR_ADDR             unwinder_cache.reserved3
sl@0: 
sl@0: /* Index table entry: */
sl@0: 
sl@0: #ifndef __EPOC32__  // Symbian OS defines this in symbian_support.h
sl@0: typedef struct __EIT_entry {
sl@0:   uint32_t fnoffset; /* Place-relative */
sl@0:   uint32_t content;
sl@0: } __EIT_entry;
sl@0: #endif
sl@0: 
sl@0: /* Private defines etc: */
sl@0: 
sl@0: static const uint32_t EXIDX_CANTUNWIND = 1;
sl@0: static const uint32_t uint32_highbit = 0x80000000;
sl@0: 
sl@0: /* ARM C++ personality routines: */
sl@0: 
sl@0: typedef _Unwind_Reason_Code (*personality_routine)(_Unwind_State,
sl@0:                                                    _Unwind_Control_Block *,
sl@0:                                                    _Unwind_Context *);
sl@0: 
sl@0: WEAKDECL _Unwind_Reason_Code __aeabi_unwind_cpp_pr0(_Unwind_State state, _Unwind_Control_Block *,
sl@0:                                                     _Unwind_Context *context);
sl@0: IMPORT_C WEAKDECL _Unwind_Reason_Code __aeabi_unwind_cpp_pr1(_Unwind_State state, _Unwind_Control_Block *,
sl@0:                                                              _Unwind_Context *context);
sl@0: IMPORT_C WEAKDECL _Unwind_Reason_Code __aeabi_unwind_cpp_pr2(_Unwind_State state, _Unwind_Control_Block *,
sl@0:                                                              _Unwind_Context *context);
sl@0: 
sl@0: 
sl@0: /* Various image symbols: */
sl@0: 
sl@0: struct ExceptionTableInfo {
sl@0:   uint32_t EIT_base;
sl@0:   uint32_t EIT_limit;
sl@0: };
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0: /* We define __ARM_ETInfo to allow access to some linker-generated
sl@0:    names that are not legal C identifiers. __ARM_ETInfo is extern only
sl@0:    because of scope limitations of the embedded assembler */
sl@0: extern const struct ExceptionTableInfo __ARM_ETInfo;
sl@0: #define EIT_base \
sl@0:     ((const __EIT_entry *)(__ARM_ETInfo.EIT_base + (const char *)&__ARM_ETInfo))
sl@0: #define EIT_limit \
sl@0:     ((const __EIT_entry *)(__ARM_ETInfo.EIT_limit + (const char *)&__ARM_ETInfo))
sl@0: 
sl@0: #endif
sl@0: 
sl@0: 
sl@0: /* ----- Index table processing ----- */
sl@0: 
sl@0: /* find_and_expand_eit_entry is a support function used in both phases to set
sl@0:  * ucb.pr_cache and internal cache.
sl@0:  * Call with a pointer to the ucb and the return address to look up.
sl@0:  *
sl@0:  * The table is contained in the half-open interval
sl@0:  * [EIT_base, EIT_limit) and is an ordered array of __EIT_entrys.
sl@0:  * Perform a binary search via C library routine bsearch.
sl@0:  * The table contains only function start addresses (encoded as offsets), so
sl@0:  * we need to special-case the end table entry in the comparison function,
sl@0:  * which we do by assuming the function it describes extends to end of memory.
sl@0:  * This causes us problems indirectly in that we would like to fault as
sl@0:  * many attempts as possible to look up an invalid return address. There are
sl@0:  * several ways an invalid return address can be obtained from a broken
sl@0:  * program, such as someone corrupting the stack or broken unwind instructions
sl@0:  * recovered the wrong value. It is plausible that many bad return addresses
sl@0:  * will be either small integers or will point into the heap or stack, hence
sl@0:  * it's desirable to get the length of that final function roughly right.
sl@0:  * Here we make no attempt to do it. Code exclusively for use in toolchains
sl@0:  * which define a suitable limit symbol could make use of that symbol.
sl@0:  * Alternatively (QoI) a smart linker could augment the index table with a
sl@0:  * dummy EXIDX_CANTUNWIND entry pointing just past the last real function.
sl@0:  */
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0: static int EIT_comparator(const void *ck, const void *ce)
sl@0: {
sl@0:   uint32_t return_address = *(const uint32_t *)ck;
sl@0:   const __EIT_entry *eitp = (const __EIT_entry *)ce;
sl@0:   const __EIT_entry *next_eitp = eitp + 1;
sl@0:   uint32_t next_fn;
sl@0:   if (next_eitp != EIT_limit)
sl@0:     next_fn = __ARM_resolve_prel31((void *)&next_eitp->fnoffset);
sl@0:   else
sl@0:     next_fn = 0xffffffffU;
sl@0:   if (return_address < __ARM_resolve_prel31((void *)&eitp->fnoffset)) return -1;
sl@0:   if (return_address >= next_fn) return 1;
sl@0:   return 0;
sl@0: }
sl@0: #endif
sl@0: 
sl@0: 
sl@0: static _Unwind_Reason_Code find_and_expand_eit_entry_V2(_Unwind_Control_Block *ucbp,
sl@0:                                                      uint32_t return_address)
sl@0: {
sl@0:   /* Search the index table for an entry containing the specified return
sl@0:    * address. Subtract the 2 from the return address, as the index table
sl@0:    * contains function start addresses (a trailing noreturn BL would
sl@0:    * appear to return to the first address of the next function (perhaps
sl@0:    * +1 if Thumb); a leading BL would appear to return to function start
sl@0:    * + instruction size (perhaps +1 if Thumb)).
sl@0:    */
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0:   const __EIT_entry *base = EIT_base;
sl@0:   size_t nelems = EIT_limit - EIT_base;
sl@0:   __EIT_entry *eitp;
sl@0: 
sl@0:   return_address -= 2;
sl@0: 
sl@0:   eitp = (__EIT_entry *) bsearch(&return_address, base, nelems,
sl@0:                                  sizeof(__EIT_entry), EIT_comparator);
sl@0: #else
sl@0:   const __EIT_entry *base = EIT_base(ucbp);
sl@0:   size_t nelems = EIT_limit(ucbp) - base;
sl@0:   __EIT_entry *eitp;
sl@0: 
sl@0:   return_address -= 2;
sl@0: 
sl@0:   // This must succeed on SymbianOS or else an error will have occured already.
sl@0:   eitp = SearchEITV2(return_address, base, nelems);
sl@0: #endif
sl@0: 
sl@0:   if (eitp == NULL) {
sl@0:     /* The return address we have was not found in the EIT.
sl@0:      * This breaks the scan and we have to indicate failure.
sl@0:      */
sl@0:     ucbp->PR_ADDR = NULL;
sl@0:     DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_UNWINDER_LOOKUPFAILED);
sl@0:     return _URC_FAILURE;
sl@0:   }
sl@0: 
sl@0:   /* Cache the function offset */
sl@0: 
sl@0:   ucbp->pr_cache.fnstart = __ARM_resolve_prel31((void *)&eitp->fnoffset);
sl@0: 
sl@0:   /* Can this frame be unwound at all? */
sl@0: 
sl@0:   if (eitp->content == EXIDX_CANTUNWIND) {
sl@0:     ucbp->PR_ADDR = NULL;
sl@0:     DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_NOUNWIND);
sl@0:     return _URC_FAILURE;
sl@0:   }
sl@0: 
sl@0:   /* Obtain the address of the "real" __EHT_Header word */
sl@0: 
sl@0:   if (eitp->content & uint32_highbit) {
sl@0:     /* It is immediate data */
sl@0:     ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content;
sl@0:     ucbp->pr_cache.additional = 1;
sl@0:   } else {
sl@0:     /* The content field is a 31-bit place-relative offset to an _Unwind_EHT_Entry structure */
sl@0:     ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)__ARM_resolve_prel31((void *)&eitp->content);
sl@0:     ucbp->pr_cache.additional = 0;
sl@0:   }
sl@0: 
sl@0:   /* Discover the personality routine address */
sl@0: 
sl@0:   if (*(uint32_t *)(ucbp->pr_cache.ehtp) & uint32_highbit) {
sl@0:     /* It is immediate data - compute matching pr */
sl@0:     uint32_t idx = ((*(uint32_t *)(ucbp->pr_cache.ehtp)) >> 24) & 0xf;
sl@0:     if (idx == 0) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr0;
sl@0:     else if (idx == 1) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr1;
sl@0:     else if (idx == 2) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr2;
sl@0:     else { /* Failed */
sl@0:       ucbp->PR_ADDR = NULL;
sl@0:       DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_TABLECORRUPT);
sl@0:       return _URC_FAILURE;
sl@0:     }
sl@0:   } else {
sl@0:     /* It's a place-relative offset to pr */
sl@0:     ucbp->PR_ADDR = __ARM_resolve_prel31((void *)(ucbp->pr_cache.ehtp));
sl@0:   }
sl@0:   return _URC_OK;
sl@0: }
sl@0: 
sl@0: static _Unwind_Reason_Code find_and_expand_eit_entry_V1(_Unwind_Control_Block *ucbp,
sl@0:                                                      uint32_t return_address)
sl@0: {
sl@0:   /* Search the index table for an entry containing the specified return
sl@0:    * address. The EIT contains function offsets relative to the base of the
sl@0:    * execute region so adjust the return address accordingly.
sl@0:    */
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0:   uint32_t return_address_offset = ADDR_TO_ER_RO_OFFSET(return_address, ucbp);
sl@0:   const __EIT_entry *base = EIT_base;
sl@0:   size_t nelems = EIT_limit - EIT_base;
sl@0: 
sl@0:    const __EIT_entry *eitp =
sl@0:      (const __EIT_entry *) bsearch(&return_address_offset, base, nelems, 
sl@0:                                    sizeof(__EIT_entry), EIT_comparator);
sl@0:   if (eitp == NULL) {
sl@0:     /* The return address we have was not found in the EIT.
sl@0:      * This breaks the scan and we have to indicate failure.
sl@0:      */
sl@0:     ucbp->PR_ADDR = NULL;
sl@0:     DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_UNWINDER_LOOKUPFAILED);
sl@0:     return _URC_FAILURE;
sl@0:   }
sl@0: #else
sl@0:   /* Shouldn't we subtract 2 from here just like in the V2 lookup? 
sl@0:    */
sl@0:   uint32_t return_address_offset = ADDR_TO_ER_RO_OFFSET(return_address, ucbp);
sl@0:   const __EIT_entry *base = EIT_base(ucbp);
sl@0:   size_t nelems = EIT_limit(ucbp) - base;
sl@0: 
sl@0:   // This must succeed or else an error will have occured already.
sl@0:   const __EIT_entry *eitp = SearchEITV1(return_address_offset, base, nelems);
sl@0: 
sl@0: #endif
sl@0: 
sl@0: 
sl@0:   /* Cache the function offset */
sl@0: 
sl@0:   ucbp->pr_cache.fnstart = ER_RO_OFFSET_TO_ADDR(eitp->fnoffset, ucbp);
sl@0: 
sl@0:   /* Can this frame be unwound at all? */
sl@0: 
sl@0:   if (eitp->content == EXIDX_CANTUNWIND) {
sl@0:     ucbp->PR_ADDR = NULL;
sl@0:     DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_NOUNWIND);
sl@0:     return _URC_FAILURE;
sl@0:   }
sl@0: 
sl@0:   /* Obtain the address of the "real" __EHT_Header word */
sl@0:   if (eitp->content & uint32_highbit) {
sl@0:     /* It is immediate data */
sl@0:     ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content;
sl@0:     ucbp->pr_cache.additional = 1;
sl@0:   } else {
sl@0:     /* The content field is a segment relative offset to an _Unwind_EHT_Entry structure */
sl@0:     ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)ER_RO_OFFSET_TO_ADDR(eitp->content, ucbp);
sl@0:     ucbp->pr_cache.additional = 0;
sl@0:   }
sl@0: 
sl@0:   /* Discover the personality routine address */
sl@0: 
sl@0:   if (*(uint32_t *)(ucbp->pr_cache.ehtp) & uint32_highbit) {
sl@0:     /* It is immediate data - compute matching pr */
sl@0:     uint32_t idx = ((*(uint32_t *)(ucbp->pr_cache.ehtp)) >> 24) & 0xf;
sl@0: 
sl@0:     if (idx == 0) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr0;
sl@0:     else if (idx == 1) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr1;
sl@0:     else if (idx == 2) ucbp->PR_ADDR = (uint32_t)&__aeabi_unwind_cpp_pr2;
sl@0:     else { /* Failed */
sl@0:       ucbp->PR_ADDR = NULL;
sl@0:       DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_TABLECORRUPT);
sl@0:       return _URC_FAILURE;
sl@0:     }
sl@0:   } else {
sl@0:     /* Execute region offset to PR */
sl@0:     ucbp->PR_ADDR = ER_RO_OFFSET_TO_ADDR(*(uint32_t *)(ucbp->pr_cache.ehtp), ucbp);
sl@0: 
sl@0:   }
sl@0:   return _URC_OK;
sl@0: }
sl@0: 
sl@0: static _Unwind_Reason_Code find_and_expand_eit_entry(_Unwind_Control_Block *ucbp,
sl@0:                                                      uint32_t return_address)
sl@0: {
sl@0:   ValidateExceptionDescriptor(return_address, ucbp);
sl@0:   if (EHABI_V2(ucbp))
sl@0:     return find_and_expand_eit_entry_V2(ucbp, return_address);
sl@0:   else
sl@0:     return find_and_expand_eit_entry_V1(ucbp, return_address);
sl@0: }
sl@0: 
sl@0: 
sl@0: /* ----- Unwinding: ----- */
sl@0: 
sl@0: /* Fwd decl */
sl@0: static NORETURNDECL void unwind_next_frame(_Unwind_Control_Block *ucbp, phase2_virtual_register_set *vrsp);
sl@0: 
sl@0: /* Helper fn: If the demand_save flag in a phase1_virtual_register_set was
sl@0:  * zeroed, the registers were demand-saved. This function restores from
sl@0:  * the save area.
sl@0: */
sl@0: static FORCEINLINE void restore_non_core_regs(phase1_virtual_register_set *vrsp)
sl@0: {
sl@0:   if (vrsp->demand_save_vfp_low == 0)
sl@0:     __ARM_Unwind_VRS_VFPrestore_low(&vrsp->vfp.d[0]);
sl@0:   if (vrsp->demand_save_vfp_high == 0)
sl@0:     __ARM_Unwind_VRS_VFPrestore_high(&vrsp->vfp.d[16]);
sl@0: }
sl@0: 
sl@0: /* _Unwind_RaiseException is the external entry point to begin unwinding */
sl@0: __asm _Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Control_Block *ucbp)
sl@0: {
sl@0:   extern __ARM_Unwind_RaiseException;
sl@0: 
sl@0: #if THUMBNAIL
sl@0: 
sl@0:   /* Create a phase2_virtual_register_set on the stack */
sl@0:   /* Save the core registers, carefully writing the original sp value */
sl@0:   /* Note we account for the pc but do not actually write it's value here */
sl@0:   str.w    r14,[sp, #-8]!;
sl@0:   add.w    r14, r13, #8;
sl@0:   str.w    r14,[sp, #-4]!  /* pushed 3 words => 3 words */
sl@0:   stmfd.w  sp!,{r0-r12};   /* pushed 13 words => 16 words */
sl@0:   /* Write zeroes for the demand_save bytes so no saving occurs in phase 2 */
sl@0:   mov.w    r1,#0;
sl@0:   str.w    r1,[sp,#-4]!;   /* pushed 1 word => 17 words */
sl@0:   mov.w    r1,sp;
sl@0:   sub.w    sp,sp,#4;       /* preserve 8 byte alignment => 18 words */
sl@0: 
sl@0:   /* Now pass to C (with r0 still valid) to do the real work.
sl@0:    * r0 = ucbp, r1 = phase2_virtual_register_set.
sl@0:    * If we get control back, pop the stack and return preserving r0.
sl@0:    */
sl@0: 
sl@0:   /* on arch 5T and later the linker will fix 'bl' => 'blx' as
sl@0:      needed */
sl@0:   bl.w     __ARM_Unwind_RaiseException;
sl@0:   ldr.w    r14,[sp,#16*4];
sl@0:   add.w    sp,sp,#18*4;
sl@0:   bx lr;
sl@0: 
sl@0: #else
sl@0: 
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0: 
sl@0:   /* Create a phase2_virtual_register_set on the stack */
sl@0:   /* Save the core registers, carefully writing the original sp value */
sl@0:   #if __ARMCC_VERSION < 300000
sl@0:   stmfd sp!,{r13-r15};  /* pushed 3 words => 3 words */
sl@0:   #else
sl@0:   stmdb r13, {r14,r15};
sl@0:   str r13, [r13,#-3*4];
sl@0:   sub r13, r13, #3*4;
sl@0:   #endif
sl@0:   stmfd sp!,{r0-r12};   /* pushed 13 words => 16 words */
sl@0:   /* Write zeroes for the demand_save bytes so no saving occurs in phase 2 */
sl@0:   mov r1,#0;
sl@0:   str r1,[sp,#-4]!;     /* pushed 1 word => 17 words */
sl@0:   mov r1,sp;
sl@0:   sub sp,sp,#4;         /* preserve 8 byte alignment => 18 words */
sl@0: 
sl@0:   /* Now pass to C (with r0 still valid) to do the real work.
sl@0:    * r0 = ucbp, r1 = phase2_virtual_register_set.
sl@0:    * If we get control back, pop the stack and return preserving r0.
sl@0:    */
sl@0: 
sl@0: #if OLD_STYLE_INTERWORKING
sl@0:   ldr r2,Unwind_RaiseException_Offset;
sl@0:   add r2,r2,pc;
sl@0:   mov lr,pc;
sl@0: Offset_Base
sl@0:   bx    r2;
sl@0: #else
sl@0:   /* on arch 5T and later the linker will fix 'bl' => 'blx' as
sl@0:      needed */
sl@0:   bl  __ARM_Unwind_RaiseException;
sl@0: #endif
sl@0:   ldr r14,[sp,#16*4];
sl@0:   add sp,sp,#18*4;
sl@0:   RET_LR;
sl@0: #if OLD_STYLE_INTERWORKING
sl@0: Unwind_RaiseException_Offset dcd __ARM_Unwind_RaiseException - Offset_Base;
sl@0: #endif
sl@0:   MAYBE_CODE16;
sl@0: 
sl@0: #endif
sl@0: 
sl@0: #ifndef __EPOC32__
sl@0:   /* Alternate symbol names for difficult symbols.
sl@0:    * It is possible no functions included in the image require
sl@0:    * a handler table. Therefore make only a weak reference to
sl@0:    * the handler table base symbol, which may be absent.
sl@0:    */
sl@0:   align 4
sl@0:   extern |.ARM.exidx$$Base|;
sl@0:   extern |.ARM.exidx$$Limit|;
sl@0:   extern |.ARM.extab$$Base| WEAKASMDECL;
sl@0:   export __ARM_ETInfo;
sl@0:   /* these are offsets for /ropi */
sl@0: __ARM_ETInfo /* layout must match struct ExceptionTableInfo */
sl@0: eit_base   dcd |.ARM.exidx$$Base|  - __ARM_ETInfo; /* index table base */
sl@0: eit_limit  dcd |.ARM.exidx$$Limit| - __ARM_ETInfo; /* index table limit */
sl@0: #endif
sl@0: }
sl@0: 
sl@0: 
sl@0: /* __ARM_Unwind_RaiseException performs phase 1 unwinding */
sl@0: 
sl@0: _Unwind_Reason_Code __ARM_Unwind_RaiseException(_Unwind_Control_Block *ucbp,
sl@0:                                                 phase2_virtual_register_set *entry_VRSp)
sl@0: {
sl@0:   phase1_virtual_register_set phase1_VRS;
sl@0: 
sl@0:   /* Is this a nested simultaneous propagation?
sl@0:    * (see comments with _Unwind_Complete)
sl@0:    */
sl@0:   if (ucbp->NESTED_CONTEXT == 0) {
sl@0:     /* No - this is only propagation */
sl@0:     ucbp->NESTED_CONTEXT = 1;
sl@0:   } else {
sl@0: #ifdef SUPPORT_NESTED_EXCEPTIONS
sl@0:     /* Yes - cache the state elsewhere and restore it when the propagation ends */
sl@0:     /* This representation wastes space and uses malloc; do better?
sl@0:      * On the other hand will it ever be used in practice?
sl@0:      */
sl@0:     _Unwind_Control_Block *saved_ucbp = AllocSavedUCB();
sl@0:     if (ucbp == NULL) {
sl@0:       DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_UNWINDER, _UAACT_ENDING, _UAARG_ENDING_UNWINDER_BUFFERFAILED);
sl@0:       return _URC_FAILURE;
sl@0:     }
sl@0:     saved_ucbp->unwinder_cache = ucbp->unwinder_cache;
sl@0:     saved_ucbp->barrier_cache = ucbp->barrier_cache;
sl@0:     saved_ucbp->cleanup_cache = ucbp->cleanup_cache;
sl@0:     ucbp->NESTED_CONTEXT = (uint32_t)saved_ucbp;
sl@0: #else
sl@0:     abort();
sl@0: #endif
sl@0:   }
sl@0: 
sl@0:   /* entry_VRSp contains the core registers as they were when
sl@0:    * _Unwind_RaiseException was called.  Copy the call-site address to r15
sl@0:    * then copy all the registers to phase1_VRS for the phase 1 stack scan.
sl@0:    */
sl@0: 
sl@0:   entry_VRSp->core.r[15] = entry_VRSp->core.r[14];
sl@0:   phase1_VRS.core = entry_VRSp->core;
sl@0: 
sl@0:   /* For phase 1 only ensure non-core registers are saved before use.
sl@0:    * If WMMX registers are supported, initialise their flags here and
sl@0:    * take appropriate action elsewhere.
sl@0:    */
sl@0: 
sl@0:   phase1_VRS.demand_save_vfp_low = 1;
sl@0:   phase1_VRS.demand_save_vfp_high = 1;
sl@0: #ifdef __EPOC32__
sl@0:   /* Set up Symbian specific caches in the _Unwind_Control_Block's 
sl@0:      unwinder_cache. 
sl@0:   */
sl@0:   InitialiseSymbianSpecificUnwinderCache(phase1_VRS.core.r[15], ucbp);
sl@0: #endif
sl@0: 
sl@0: 
sl@0:   /* Now perform a virtual unwind until a propagation barrier is met, or
sl@0:    * until something goes wrong.  If something does go wrong, we ought (I
sl@0:    * suppose) to restore registers we may have destroyed.
sl@0:    */
sl@0: 
sl@0:   while (1) {
sl@0: 
sl@0:     _Unwind_Reason_Code pr_result;
sl@0: 
sl@0:     /* Search the index table for the required entry.  Cache the index table
sl@0:      * pointer, and obtain and cache the addresses of the "real" __EHT_Header
sl@0:      * word and the personality routine.
sl@0:      */
sl@0: 
sl@0:     if (find_and_expand_eit_entry(ucbp, phase1_VRS.core.r[15]) != _URC_OK) {
sl@0:       restore_non_core_regs(&phase1_VRS);
sl@0:       /* Debugger bottleneck fn called during lookup */
sl@0:       return _URC_FAILURE;
sl@0:     }
sl@0: 
sl@0:     /* Call the pr to decide what to do */
sl@0: 
sl@0:     pr_result = ((personality_routine)ucbp->PR_ADDR)(_US_VIRTUAL_UNWIND_FRAME,
sl@0:                                                      ucbp,
sl@0:                                                      (_Unwind_Context *)&phase1_VRS);
sl@0: 
sl@0:     if (pr_result == _URC_HANDLER_FOUND) break;
sl@0:     if (pr_result == _URC_CONTINUE_UNWIND) continue;
sl@0: 
sl@0:     /* If we get here some sort of failure has occurred in the
sl@0:      * pr and probably the pr returned _URC_FAILURE
sl@0:      */
sl@0:     restore_non_core_regs(&phase1_VRS);
sl@0:     return _URC_FAILURE;
sl@0:   }
sl@0: 
sl@0:   /* Propagation barrier located... restore entry register state of non-core regs */
sl@0: 
sl@0:   restore_non_core_regs(&phase1_VRS);
sl@0: 
sl@0:   /* Initiate real unwinding */
sl@0:   unwind_next_frame(ucbp, entry_VRSp);
sl@0:   /* Unreached, but keep compiler quiet: */
sl@0:   return _URC_FAILURE;
sl@0: }
sl@0: 
sl@0: 
sl@0: /* unwind_next_frame performs phase 2 unwinding */
sl@0: 
sl@0: static NORETURNDECL void unwind_next_frame(_Unwind_Control_Block *ucbp, phase2_virtual_register_set *vrsp)
sl@0: {
sl@0:   while (1) {
sl@0: 
sl@0:     _Unwind_Reason_Code pr_result;
sl@0: 
sl@0:     /* Search the index table for the required entry.  Cache the index table
sl@0:      * pointer, and obtain and cache the addresses of the "real" __EHT_Header
sl@0:      * word and the personality routine.
sl@0:      */
sl@0: 
sl@0:     if (find_and_expand_eit_entry(ucbp, vrsp->core.r[15]) != _URC_OK)
sl@0:       abort();
sl@0: 
sl@0:     /* Save the call-site address and call the pr to do whatever it
sl@0:      * wants to do on this new frame.
sl@0:      */
sl@0: 
sl@0:     ucbp->SAVED_CALLSITE_ADDR = vrsp->core.r[15];
sl@0:     pr_result = ((personality_routine)ucbp->PR_ADDR)(_US_UNWIND_FRAME_STARTING, ucbp,
sl@0:                                                      (_Unwind_Context *)vrsp);
sl@0: 
sl@0:     if (pr_result == _URC_INSTALL_CONTEXT) {
sl@0:       /* Upload the registers */
sl@0:       __ARM_Unwind_VRS_corerestore(&vrsp->core);
sl@0:     } else if (pr_result == _URC_CONTINUE_UNWIND)
sl@0:       continue;
sl@0:     else
sl@0:       abort();
sl@0:   }
sl@0: }
sl@0: 
sl@0: 
sl@0: /* _Unwind_Resume is the external entry point called after a cleanup
sl@0:  * to resume unwinding. It tail-calls a helper function,
sl@0:  * __ARM_Unwind_Resume, which never returns.
sl@0:  */
sl@0: __asm NORETURNDECL void _Unwind_Resume(_Unwind_Control_Block *ucbp)
sl@0: {
sl@0:   extern __ARM_Unwind_Resume;
sl@0: 
sl@0: #if THUMBNAIL
sl@0: 
sl@0:   /* Create a phase2_virtual_register_set on the stack */
sl@0:   /* Save the core registers, carefully writing the original sp value */
sl@0:   /* Note we account for the pc but do not actually write it's value here */
sl@0:   str.w    r14,[sp, #-8]!;
sl@0:   add.w    r14, r13, #8;
sl@0:   str.w    r14,[sp, #-4]!    /* pushed 3 words => 3 words */
sl@0:   stmfd.w  sp!,{r0-r12};     /* pushed 13 words => 16 words */
sl@0:   /* Write zeroes for the demand_save bytes so no saving occurs in phase 2 */
sl@0:   mov.w    r1,#0;
sl@0:   str.w    r1,[sp,#-4]!;     /* pushed 1 word => 17 words */
sl@0:   mov.w    r1,sp;
sl@0:   sub.w    sp,sp,#4;         /* preserve 8 byte alignment => 18 words */
sl@0: 
sl@0:   /* Now pass to C (with r0 still valid) to do the real work.
sl@0:    * r0 = ucbp, r1 = phase2_virtual_register_set.
sl@0:    * This call never returns.
sl@0:    */
sl@0: 
sl@0:   mov      pc,r2
sl@0: 
sl@0: #else
sl@0: 
sl@0:   MAYBE_SWITCH_TO_ARM_STATE;
sl@0: 
sl@0:   /* Create a phase2_virtual_register_set on the stack */
sl@0:   /* Save the core registers, carefully writing the original sp value */
sl@0: 
sl@0:   #if __ARMCC_VERSION < 300000
sl@0:   stmfd sp!,{r13-r15};  /* pushed 3 words => 3 words */
sl@0:   #else
sl@0:   stmdb r13, {r14,r15};
sl@0:   str r13, [r13,#-3*4];
sl@0:   sub r13, r13, #3*4;
sl@0:   #endif
sl@0: 
sl@0:   stmfd sp!,{r0-r12};   /* pushed 13 words => 16 words */
sl@0:   /* Write zeroes for the demand_save bytes so no saving occurs in phase 2 */
sl@0:   mov r1,#0;
sl@0:   str r1,[sp,#-4]!;     /* pushed 1 word => 17 words */
sl@0:   mov r1,sp;
sl@0:   sub sp,sp,#4;         /* preserve 8 byte alignment => 18 words */
sl@0: 
sl@0:   /* Now pass to C (with r0 still valid) to do the real work.
sl@0:    * r0 = ucbp, r1 = phase2_virtual_register_set.
sl@0:    * This call never returns.
sl@0:    */
sl@0: 
sl@0: #ifdef __APCS_INTERWORK
sl@0:   ldr r2,Unwind_Resume_Offset;
sl@0:   add r2,r2,pc;
sl@0:   bx    r2;
sl@0: Unwind_Resume_Offset dcd __ARM_Unwind_Resume - .;
sl@0: #else
sl@0:   b __ARM_Unwind_Resume;
sl@0: #endif
sl@0:   MAYBE_CODE16;
sl@0: 
sl@0: #endif
sl@0: }
sl@0: 
sl@0: 
sl@0: /* Helper function for _Unwind_Resume */
sl@0: 
sl@0: NORETURNDECL void __ARM_Unwind_Resume(_Unwind_Control_Block *ucbp,
sl@0:                                   phase2_virtual_register_set *entry_VRSp)
sl@0: {
sl@0:   _Unwind_Reason_Code pr_result;
sl@0: 
sl@0:   /* Recover saved state */
sl@0: 
sl@0:   entry_VRSp->core.r[15] = ucbp->SAVED_CALLSITE_ADDR;
sl@0: 
sl@0:   /* Call the cached PR and dispatch */
sl@0: 
sl@0:   pr_result = ((personality_routine)ucbp->PR_ADDR)(_US_UNWIND_FRAME_RESUME, ucbp,
sl@0:                                                    (_Unwind_Context *)entry_VRSp);
sl@0: 
sl@0:   if (pr_result == _URC_INSTALL_CONTEXT) {
sl@0:    /* Upload the registers */
sl@0:     __ARM_Unwind_VRS_corerestore(&entry_VRSp->core);
sl@0:   } else if (pr_result == _URC_CONTINUE_UNWIND)
sl@0:     unwind_next_frame(ucbp, entry_VRSp);
sl@0:   else
sl@0:     abort();
sl@0: }
sl@0: 
sl@0: 
sl@0: /* _Unwind_Complete is called at the end of a propagation.
sl@0:  * If we support multiple simultaneous propagations, restore the cached state
sl@0:  * of the previous propagation here.
sl@0:  */
sl@0: 
sl@0: void _Unwind_Complete(_Unwind_Control_Block *ucbp)
sl@0: {
sl@0:   _Unwind_Control_Block *context = (_Unwind_Control_Block *)ucbp->NESTED_CONTEXT;
sl@0:   if ((uint32_t)context == 0) abort();  /* should be impossible */
sl@0:   if ((uint32_t)context == 1) {
sl@0:     /* This was the only ongoing propagation of this object */
sl@0:     ucbp->NESTED_CONTEXT--;
sl@0:     return;
sl@0:   }
sl@0: #ifdef SUPPORT_NESTED_EXCEPTIONS
sl@0:   /* Otherwise we copy the state back from the cache structure pointed to
sl@0:    * by ucbp->NESTED_CONTEXT.
sl@0:    */
sl@0:   /* This first one updates ucbp->NESTED_CONTEXT */
sl@0:   ucbp->unwinder_cache = context->unwinder_cache;
sl@0:   ucbp->barrier_cache = context->barrier_cache;
sl@0:   ucbp->cleanup_cache = context->cleanup_cache;
sl@0:   FreeSavedUCB(context);
sl@0: #else
sl@0:   abort();
sl@0: #endif
sl@0: }
sl@0: 
sl@0: /* _Unwind_DeleteException can be used to invoke the exception_cleanup
sl@0:  * function after catching a foreign exception.
sl@0:  */
sl@0: 
sl@0: void _Unwind_DeleteException(_Unwind_Control_Block *ucbp)
sl@0: {
sl@0:   if (ucbp->exception_cleanup != NULL)
sl@0:     (ucbp->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT, ucbp);
sl@0: }
sl@0: 
sl@0: #endif /* unwinder_c */
sl@0: #ifdef unwind_activity_c
sl@0: 
sl@0: /* Runtime debug "bottleneck function": */
sl@0: /* (not in the current Exceptions EABI document) */
sl@0: 
sl@0: void _Unwind_Activity(_Unwind_Control_Block *ucbp, uint32_t reason, uint32_t arg)
sl@0: {
sl@0: #ifdef UNWIND_ACTIVITY_DIAGNOSTICS
sl@0:   uint32_t who = reason >> 24;
sl@0:   uint32_t activity = reason & 0xffffff;
sl@0:   printf("_Unwind_Activity: UCB=0x%8.8x Reason=(", (uint32_t)ucbp);
sl@0:   switch (who) {
sl@0:   case _UASUBSYS_UNWINDER:
sl@0:     printf("unw,");
sl@0:     if (activity >= 0x80)
sl@0:       printf("%x) Arg=0x%8.8x\n", activity, arg);
sl@0:     break;
sl@0:   case _UASUBSYS_CPP:
sl@0:     printf("C++,");
sl@0:     if (activity >= 0x80) {
sl@0:       if (activity == _UAACT_CPP_TYPEINFO)
sl@0:         printf("typeinfo) Typeinfo=0x%8.8x\n", arg);
sl@0:       else
sl@0:         printf("%x) Arg=0x%8.8x\n", activity, arg);
sl@0:     }
sl@0:     break;
sl@0:   default:
sl@0:     printf("???,");
sl@0:     if (activity >= 0x80)
sl@0:       printf("%x) Arg=0x%8.8x\n", activity, arg);
sl@0:     break;
sl@0:   }
sl@0:   if (activity < 0x80) {
sl@0:     switch (activity) {
sl@0:     case _UAACT_STARTING:
sl@0:       printf("starting) Typeinfo=0x%8.8x\n", arg);
sl@0:       break;
sl@0:     case _UAACT_ENDING:
sl@0:       printf("ending) Cause=%d\n", arg);
sl@0:       break;
sl@0:     case _UAACT_BARRIERFOUND:
sl@0:       printf("barrierfound) Pad=0x%8.8x\n", arg);
sl@0:       break;
sl@0:     case _UAACT_PADENTRY:
sl@0:       printf("padentry) Pad=0x%8.8x\n", arg);
sl@0:       break;
sl@0:     default:
sl@0:       printf("%x) Arg=0x%8.8x\n", activity, arg);
sl@0:       break;
sl@0:     }
sl@0:   }
sl@0: #endif
sl@0: }
sl@0: 
sl@0: #endif /* unwind_activity_c */