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Diffstat (limited to 'gcc/config/xtensa/unwind-dw2-xtensa.c')
| -rw-r--r-- | gcc/config/xtensa/unwind-dw2-xtensa.c | 544 |
1 files changed, 0 insertions, 544 deletions
diff --git a/gcc/config/xtensa/unwind-dw2-xtensa.c b/gcc/config/xtensa/unwind-dw2-xtensa.c deleted file mode 100644 index 54daf7637ce..00000000000 --- a/gcc/config/xtensa/unwind-dw2-xtensa.c +++ /dev/null @@ -1,544 +0,0 @@ -/* DWARF2 exception handling and frame unwinding for Xtensa. - Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, - 2007, 2008, 2009, 2011 - Free Software Foundation, Inc. - - This file is part of GCC. - - GCC 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. - - GCC 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 "tconfig.h" -#include "tsystem.h" -#include "coretypes.h" -#include "tm.h" -#include "dwarf2.h" -#include "unwind.h" -#ifdef __USING_SJLJ_EXCEPTIONS__ -# define NO_SIZE_OF_ENCODED_VALUE -#endif -#include "unwind-pe.h" -#include "unwind-dw2-fde.h" -#include "unwind-dw2-xtensa.h" - -#ifndef __USING_SJLJ_EXCEPTIONS__ - -/* The standard CIE and FDE structures work fine for Xtensa but the - variable-size register window save areas are not a good fit for the rest - of the standard DWARF unwinding mechanism. Nor is that mechanism - necessary, since the register save areas are always in fixed locations - in each stack frame. This file is a stripped down and customized version - of the standard DWARF unwinding code. It needs to be customized to have - builtin logic for finding the save areas and also to track the stack - pointer value (besides the CFA) while unwinding since the primary save - area is located below the stack pointer. It is stripped down to reduce - code size and ease the maintenance burden of tracking changes in the - standard version of the code. */ - -#ifndef DWARF_REG_TO_UNWIND_COLUMN -#define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO) -#endif - -#define XTENSA_RA_FIELD_MASK 0x3FFFFFFF - -/* This is the register and unwind state for a particular frame. This - provides the information necessary to unwind up past a frame and return - to its caller. */ -struct _Unwind_Context -{ - /* Track register window save areas of 4 registers each, instead of - keeping separate addresses for the individual registers. */ - _Unwind_Word *reg[4]; - - void *cfa; - void *sp; - void *ra; - - /* Cache the 2 high bits to replace the window size in return addresses. */ - _Unwind_Word ra_high_bits; - - void *lsda; - struct dwarf_eh_bases bases; - /* Signal frame context. */ -#define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1) - _Unwind_Word flags; - /* 0 for now, can be increased when further fields are added to - struct _Unwind_Context. */ - _Unwind_Word version; -}; - - -/* Read unaligned data from the instruction buffer. */ - -union unaligned -{ - void *p; -} __attribute__ ((packed)); - -static void uw_update_context (struct _Unwind_Context *, _Unwind_FrameState *); -static _Unwind_Reason_Code uw_frame_state_for (struct _Unwind_Context *, - _Unwind_FrameState *); - -static inline void * -read_pointer (const void *p) { const union unaligned *up = p; return up->p; } - -static inline _Unwind_Word -_Unwind_IsSignalFrame (struct _Unwind_Context *context) -{ - return (context->flags & SIGNAL_FRAME_BIT) ? 1 : 0; -} - -static inline void -_Unwind_SetSignalFrame (struct _Unwind_Context *context, int val) -{ - if (val) - context->flags |= SIGNAL_FRAME_BIT; - else - context->flags &= ~SIGNAL_FRAME_BIT; -} - -/* Get the value of register INDEX as saved in CONTEXT. */ - -inline _Unwind_Word -_Unwind_GetGR (struct _Unwind_Context *context, int index) -{ - _Unwind_Word *ptr; - - index = DWARF_REG_TO_UNWIND_COLUMN (index); - ptr = context->reg[index >> 2] + (index & 3); - - return *ptr; -} - -/* Get the value of the CFA as saved in CONTEXT. */ - -_Unwind_Word -_Unwind_GetCFA (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->cfa; -} - -/* Overwrite the saved value for register INDEX in CONTEXT with VAL. */ - -inline void -_Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) -{ - _Unwind_Word *ptr; - - index = DWARF_REG_TO_UNWIND_COLUMN (index); - ptr = context->reg[index >> 2] + (index & 3); - - *ptr = val; -} - -/* Retrieve the return address for CONTEXT. */ - -inline _Unwind_Ptr -_Unwind_GetIP (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->ra; -} - -/* Retrieve the return address and flag whether that IP is before - or after first not yet fully executed instruction. */ - -inline _Unwind_Ptr -_Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn) -{ - *ip_before_insn = _Unwind_IsSignalFrame (context); - return (_Unwind_Ptr) context->ra; -} - -/* Overwrite the return address for CONTEXT with VAL. */ - -inline void -_Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) -{ - context->ra = (void *) val; -} - -void * -_Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) -{ - return context->lsda; -} - -_Unwind_Ptr -_Unwind_GetRegionStart (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.func; -} - -void * -_Unwind_FindEnclosingFunction (void *pc) -{ - struct dwarf_eh_bases bases; - const struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases); - if (fde) - return bases.func; - else - return NULL; -} - -_Unwind_Ptr -_Unwind_GetDataRelBase (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.dbase; -} - -_Unwind_Ptr -_Unwind_GetTextRelBase (struct _Unwind_Context *context) -{ - return (_Unwind_Ptr) context->bases.tbase; -} - -#include "md-unwind-support.h" - -/* Extract any interesting information from the CIE for the translation - unit F belongs to. Return a pointer to the byte after the augmentation, - or NULL if we encountered an undecipherable augmentation. */ - -static const unsigned char * -extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context, - _Unwind_FrameState *fs) -{ - const unsigned char *aug = cie->augmentation; - const unsigned char *p = aug + strlen ((const char *)aug) + 1; - const unsigned char *ret = NULL; - _uleb128_t utmp; - _sleb128_t stmp; - - /* g++ v2 "eh" has pointer immediately following augmentation string, - so it must be handled first. */ - if (aug[0] == 'e' && aug[1] == 'h') - { - fs->eh_ptr = read_pointer (p); - p += sizeof (void *); - aug += 2; - } - - /* Immediately following the augmentation are the code and - data alignment and return address column. */ - p = read_uleb128 (p, &utmp); - p = read_sleb128 (p, &stmp); - if (cie->version == 1) - fs->retaddr_column = *p++; - else - { - p = read_uleb128 (p, &utmp); - fs->retaddr_column = (_Unwind_Word)utmp; - } - fs->lsda_encoding = DW_EH_PE_omit; - - /* If the augmentation starts with 'z', then a uleb128 immediately - follows containing the length of the augmentation field following - the size. */ - if (*aug == 'z') - { - p = read_uleb128 (p, &utmp); - ret = p + utmp; - - fs->saw_z = 1; - ++aug; - } - - /* Iterate over recognized augmentation subsequences. */ - while (*aug != '\0') - { - /* "L" indicates a byte showing how the LSDA pointer is encoded. */ - if (aug[0] == 'L') - { - fs->lsda_encoding = *p++; - aug += 1; - } - - /* "R" indicates a byte indicating how FDE addresses are encoded. */ - else if (aug[0] == 'R') - { - fs->fde_encoding = *p++; - aug += 1; - } - - /* "P" indicates a personality routine in the CIE augmentation. */ - else if (aug[0] == 'P') - { - _Unwind_Ptr personality; - - p = read_encoded_value (context, *p, p + 1, &personality); - fs->personality = (_Unwind_Personality_Fn) personality; - aug += 1; - } - - /* "S" indicates a signal frame. */ - else if (aug[0] == 'S') - { - fs->signal_frame = 1; - aug += 1; - } - - /* Otherwise we have an unknown augmentation string. - Bail unless we saw a 'z' prefix. */ - else - return ret; - } - - return ret ? ret : p; -} - -/* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for - its caller and decode it into FS. This function also sets the - lsda member of CONTEXT, as it is really information - about the caller's frame. */ - -static _Unwind_Reason_Code -uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - const struct dwarf_fde *fde; - const struct dwarf_cie *cie; - const unsigned char *aug; - int window_size; - _Unwind_Word *ra_ptr; - - memset (fs, 0, sizeof (*fs)); - context->lsda = 0; - - fde = _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context) - 1, - &context->bases); - if (fde == NULL) - { -#ifdef MD_FALLBACK_FRAME_STATE_FOR - _Unwind_Reason_Code reason; - /* Couldn't find frame unwind info for this function. Try a - target-specific fallback mechanism. This will necessarily - not provide a personality routine or LSDA. */ - reason = MD_FALLBACK_FRAME_STATE_FOR (context, fs); - if (reason != _URC_END_OF_STACK) - return reason; -#endif - /* The frame was not recognized and handled by the fallback function, - but it is not really the end of the stack. Fall through here and - unwind it anyway. */ - } - else - { - cie = get_cie (fde); - if (extract_cie_info (cie, context, fs) == NULL) - /* CIE contained unknown augmentation. */ - return _URC_FATAL_PHASE1_ERROR; - - /* Locate augmentation for the fde. */ - aug = (const unsigned char *) fde + sizeof (*fde); - aug += 2 * size_of_encoded_value (fs->fde_encoding); - if (fs->saw_z) - { - _uleb128_t i; - aug = read_uleb128 (aug, &i); - } - if (fs->lsda_encoding != DW_EH_PE_omit) - { - _Unwind_Ptr lsda; - - aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda); - context->lsda = (void *) lsda; - } - } - - /* Check for the end of the stack. This needs to be checked after - the MD_FALLBACK_FRAME_STATE_FOR check for signal frames because - the contents of context->reg[0] are undefined at a signal frame, - and register a0 may appear to be zero. (The return address in - context->ra comes from register a4 or a8). */ - ra_ptr = context->reg[0]; - if (ra_ptr && *ra_ptr == 0) - return _URC_END_OF_STACK; - - /* Find the window size from the high bits of the return address. */ - if (ra_ptr) - window_size = (*ra_ptr >> 30) * 4; - else - window_size = 8; - - fs->retaddr_column = window_size; - - return _URC_NO_REASON; -} - -static void -uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - struct _Unwind_Context orig_context = *context; - _Unwind_Word *sp, *cfa, *next_cfa; - int i; - - if (fs->signal_regs) - { - cfa = (_Unwind_Word *) fs->signal_regs[1]; - next_cfa = (_Unwind_Word *) cfa[-3]; - - for (i = 0; i < 4; i++) - context->reg[i] = fs->signal_regs + (i << 2); - } - else - { - int window_size = fs->retaddr_column >> 2; - - sp = (_Unwind_Word *) orig_context.sp; - cfa = (_Unwind_Word *) orig_context.cfa; - next_cfa = (_Unwind_Word *) cfa[-3]; - - /* Registers a0-a3 are in the save area below sp. */ - context->reg[0] = sp - 4; - - /* Find the extra save area below next_cfa. */ - for (i = 1; i < window_size; i++) - context->reg[i] = next_cfa - 4 * (1 + window_size - i); - - /* Remaining registers rotate from previous save areas. */ - for (i = window_size; i < 4; i++) - context->reg[i] = orig_context.reg[i - window_size]; - } - - context->sp = cfa; - context->cfa = next_cfa; - - _Unwind_SetSignalFrame (context, fs->signal_frame); -} - -/* CONTEXT describes the unwind state for a frame, and FS describes the FDE - of its caller. Update CONTEXT to refer to the caller as well. Note - that the lsda member is not updated here, but later in - uw_frame_state_for. */ - -static void -uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - uw_update_context_1 (context, fs); - - /* Compute the return address now, since the return address column - can change from frame to frame. */ - if (fs->signal_ra != 0) - context->ra = (void *) fs->signal_ra; - else - context->ra = (void *) ((_Unwind_GetGR (context, fs->retaddr_column) - & XTENSA_RA_FIELD_MASK) | context->ra_high_bits); -} - -static void -uw_advance_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) -{ - uw_update_context (context, fs); -} - -/* 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 \ - { \ - __builtin_unwind_init (); \ - uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \ - __builtin_return_address (0)); \ - } \ - while (0) - -static void __attribute__((noinline)) -uw_init_context_1 (struct _Unwind_Context *context, void *outer_cfa, - void *outer_ra) -{ - void *ra = __builtin_return_address (0); - void *cfa = __builtin_dwarf_cfa (); - _Unwind_FrameState fs; - - memset (context, 0, sizeof (struct _Unwind_Context)); - context->ra = ra; - - memset (&fs, 0, sizeof (fs)); - fs.retaddr_column = 8; - context->sp = cfa; - context->cfa = outer_cfa; - context->ra_high_bits = - ((_Unwind_Word) uw_init_context_1) & ~XTENSA_RA_FIELD_MASK; - uw_update_context_1 (context, &fs); - - context->ra = 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 long -uw_install_context_1 (struct _Unwind_Context *current, - struct _Unwind_Context *target) -{ - long i; - - /* The eh_return insn assumes a window size of 8, so don't bother copying - the save areas for registers a8-a15 since they won't be reloaded. */ - for (i = 0; i < 2; ++i) - { - void *c = current->reg[i]; - void *t = target->reg[i]; - - if (t && c && t != c) - memcpy (c, t, 4 * sizeof (_Unwind_Word)); - } - - return 0; -} - -static inline _Unwind_Ptr -uw_identify_context (struct _Unwind_Context *context) -{ - return _Unwind_GetCFA (context); -} - - -#include "unwind.inc" - -#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS) -alias (_Unwind_Backtrace); -alias (_Unwind_DeleteException); -alias (_Unwind_FindEnclosingFunction); -alias (_Unwind_ForcedUnwind); -alias (_Unwind_GetDataRelBase); -alias (_Unwind_GetTextRelBase); -alias (_Unwind_GetCFA); -alias (_Unwind_GetGR); -alias (_Unwind_GetIP); -alias (_Unwind_GetLanguageSpecificData); -alias (_Unwind_GetRegionStart); -alias (_Unwind_RaiseException); -alias (_Unwind_Resume); -alias (_Unwind_Resume_or_Rethrow); -alias (_Unwind_SetGR); -alias (_Unwind_SetIP); -#endif - -#endif /* !USING_SJLJ_EXCEPTIONS */ |