2 * unwind.c: Stack Unwinding Interface
5 * Zoltan Varga (vargaz@gmail.com)
7 * (C) 2008 Novell, Inc.
11 #include "mini-unwind.h"
13 #include <mono/utils/mono-counters.h>
14 #include <mono/utils/freebsd-dwarf.h>
15 #include <mono/utils/hazard-pointer.h>
16 #include <mono/metadata/threads-types.h>
17 #include <mono/metadata/mono-endian.h>
31 guint8 info [MONO_ZERO_LEN_ARRAY];
34 static CRITICAL_SECTION unwind_mutex;
36 static MonoUnwindInfo **cached_info;
37 static int cached_info_next, cached_info_size;
38 static GSList *cached_info_list;
40 static int unwind_info_size;
42 #define unwind_lock() EnterCriticalSection (&unwind_mutex)
43 #define unwind_unlock() LeaveCriticalSection (&unwind_mutex)
46 static int map_hw_reg_to_dwarf_reg [] = { 0, 2, 1, 3, 7, 6, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
47 #define NUM_REGS AMD64_NREG
48 #define DWARF_DATA_ALIGN (-8)
49 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (AMD64_RIP))
50 #elif defined(TARGET_ARM)
51 // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040a/IHI0040A_aadwarf.pdf
52 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
54 #define DWARF_DATA_ALIGN (-4)
55 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (ARMREG_LR))
56 #elif defined (TARGET_X86)
59 * LLVM seems to generate unwind info where esp is encoded as 5, and ebp as 4, ie see this line:
60 * def ESP : RegisterWithSubRegs<"esp", [SP]>, DwarfRegNum<[-2, 5, 4]>;
61 * in lib/Target/X86/X86RegisterInfo.td in the llvm sources.
63 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 5, 4, 6, 7, 8 };
65 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
68 #define NUM_REGS X86_NREG + 1
69 #define DWARF_DATA_ALIGN (-4)
70 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (X86_NREG))
71 #elif defined (TARGET_POWERPC)
72 // http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
73 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8,
74 9, 10, 11, 12, 13, 14, 15, 16,
75 17, 18, 19, 20, 21, 22, 23, 24,
76 25, 26, 27, 28, 29, 30, 31 };
78 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
79 #define DWARF_PC_REG 108
80 #elif defined (TARGET_S390X)
81 static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
83 #define DWARF_DATA_ALIGN (-8)
84 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (14))
85 #elif defined (TARGET_MIPS)
87 static int map_hw_reg_to_dwarf_reg [32] = {
88 0, 1, 2, 3, 4, 5, 6, 7,
89 8, 9, 10, 11, 12, 13, 14, 15,
90 16, 17, 18, 19, 20, 21, 22, 23,
91 24, 25, 26, 27, 28, 29, 30, 31
94 #define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
95 #define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (mips_ra))
97 static int map_hw_reg_to_dwarf_reg [16];
99 #define DWARF_DATA_ALIGN 0
100 #define DWARF_PC_REG -1
103 static gboolean dwarf_reg_to_hw_reg_inited;
105 static int map_dwarf_reg_to_hw_reg [NUM_REGS];
108 * mono_hw_reg_to_dwarf_reg:
110 * Map the hardware register number REG to the register number used by DWARF.
113 mono_hw_reg_to_dwarf_reg (int reg)
115 #ifdef TARGET_POWERPC
119 g_assert (reg < NUM_REGS);
123 g_assert_not_reached ();
126 return map_hw_reg_to_dwarf_reg [reg];
135 g_assert (NUM_REGS > 0);
136 for (i = 0; i < sizeof (map_hw_reg_to_dwarf_reg) / sizeof (int); ++i) {
137 map_dwarf_reg_to_hw_reg [mono_hw_reg_to_dwarf_reg (i)] = i;
140 #ifdef TARGET_POWERPC
141 map_dwarf_reg_to_hw_reg [DWARF_PC_REG] = ppc_lr;
144 mono_memory_barrier ();
145 dwarf_reg_to_hw_reg_inited = TRUE;
149 mono_dwarf_reg_to_hw_reg (int reg)
151 if (!dwarf_reg_to_hw_reg_inited)
154 return map_dwarf_reg_to_hw_reg [reg];
157 static G_GNUC_UNUSED void
158 encode_uleb128 (guint32 value, guint8 *buf, guint8 **endbuf)
163 guint8 b = value & 0x7f;
165 if (value != 0) /* more bytes to come */
173 static G_GNUC_UNUSED void
174 encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
177 gboolean negative = (value < 0);
185 /* the following is unnecessary if the
186 * implementation of >>= uses an arithmetic rather
187 * than logical shift for a signed left operand
191 value |= - (1 <<(size - 7));
192 /* sign bit of byte is second high order bit (0x40) */
193 if ((value == 0 && !(byte & 0x40)) ||
194 (value == -1 && (byte & 0x40)))
204 static inline guint32
205 decode_uleb128 (guint8 *buf, guint8 **endbuf)
215 res = res | (((int)(b & 0x7f)) << shift);
227 decode_sleb128 (guint8 *buf, guint8 **endbuf)
237 res = res | (((int)(b & 0x7f)) << shift);
240 if (shift < 32 && (b & 0x40))
241 res |= - (1 << shift);
252 * mono_unwind_ops_encode:
254 * Encode the unwind ops in UNWIND_OPS into the compact DWARF encoding.
255 * Return a pointer to malloc'ed memory.
258 mono_unwind_ops_encode (GSList *unwind_ops, guint32 *out_len)
263 guint8 *buf, *p, *res;
265 p = buf = g_malloc0 (4096);
269 for (; l; l = l->next) {
274 /* Convert the register from the hw encoding to the dwarf encoding */
275 reg = mono_hw_reg_to_dwarf_reg (op->reg);
277 /* Emit an advance_loc if neccesary */
278 while (op->when > loc) {
279 if (op->when - loc < 32) {
280 *p ++ = DW_CFA_advance_loc | (op->when - loc);
283 *p ++ = DW_CFA_advance_loc | (30);
291 encode_uleb128 (reg, p, &p);
292 encode_uleb128 (op->val, p, &p);
294 case DW_CFA_def_cfa_offset:
296 encode_uleb128 (op->val, p, &p);
298 case DW_CFA_def_cfa_register:
300 encode_uleb128 (reg, p, &p);
304 *p ++ = DW_CFA_offset_extended_sf;
305 encode_uleb128 (reg, p, &p);
306 encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
308 *p ++ = DW_CFA_offset | reg;
309 encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
313 g_assert_not_reached ();
318 g_assert (p - buf < 4096);
320 res = g_malloc (p - buf);
321 memcpy (res, buf, p - buf);
327 #define UNW_DEBUG(stmt) do { stmt; } while (0)
329 #define UNW_DEBUG(stmt) do { } while (0)
332 static G_GNUC_UNUSED void
333 print_dwarf_state (int cfa_reg, int cfa_offset, int ip, int nregs, Loc *locations)
337 printf ("\t%x: cfa=r%d+%d ", ip, cfa_reg, cfa_offset);
339 for (i = 0; i < nregs; ++i)
340 if (locations [i].loc_type == LOC_OFFSET)
341 printf ("r%d@%d(cfa) ", i, locations [i].offset);
346 * Given the state of the current frame as stored in REGS, execute the unwind
347 * operations in unwind_info until the location counter reaches POS. The result is
348 * stored back into REGS. OUT_CFA will receive the value of the CFA.
349 * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
350 * On return, the nth entry will point to the address of the stack slot where register
351 * N was saved, or NULL, if it was not saved by this frame.
352 * This function is signal safe.
355 mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
356 guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs, int nregs,
357 mgreg_t **save_locations, int save_locations_len,
360 Loc locations [NUM_REGS];
361 int i, pos, reg, cfa_reg, cfa_offset;
365 for (i = 0; i < NUM_REGS; ++i)
366 locations [i].loc_type = LOC_SAME;
372 while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
376 case DW_CFA_advance_loc:
377 UNW_DEBUG (print_dwarf_state (cfa_reg, cfa_offset, pos, nregs, locations));
384 locations [reg].loc_type = LOC_OFFSET;
385 locations [reg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
392 cfa_reg = decode_uleb128 (p, &p);
393 cfa_offset = decode_uleb128 (p, &p);
395 case DW_CFA_def_cfa_offset:
396 cfa_offset = decode_uleb128 (p, &p);
398 case DW_CFA_def_cfa_register:
399 cfa_reg = decode_uleb128 (p, &p);
401 case DW_CFA_offset_extended_sf:
402 reg = decode_uleb128 (p, &p);
403 locations [reg].loc_type = LOC_OFFSET;
404 locations [reg].offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
406 case DW_CFA_advance_loc4:
411 g_assert_not_reached ();
416 g_assert_not_reached ();
421 memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
423 cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
424 for (i = 0; i < NUM_REGS; ++i) {
425 if (locations [i].loc_type == LOC_OFFSET) {
426 int hreg = mono_dwarf_reg_to_hw_reg (i);
427 g_assert (hreg < nregs);
428 regs [hreg] = *(mgreg_t*)(cfa_val + locations [i].offset);
429 if (save_locations && hreg < save_locations_len)
430 save_locations [hreg] = (mgreg_t*)(cfa_val + locations [i].offset);
438 mono_unwind_init (void)
440 InitializeCriticalSection (&unwind_mutex);
442 mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
446 mono_unwind_cleanup (void)
450 DeleteCriticalSection (&unwind_mutex);
455 for (i = 0; i < cached_info_next; ++i) {
456 MonoUnwindInfo *cached = cached_info [i];
461 g_free (cached_info);
465 * mono_cache_unwind_info
467 * Save UNWIND_INFO in the unwind info cache and return an id which can be passed
468 * to mono_get_cached_unwind_info to get a cached copy of the info.
469 * A copy is made of the unwind info.
470 * This function is useful for two reasons:
471 * - many methods have the same unwind info
472 * - MonoJitInfo->used_regs is an int so it can't store the pointer to the unwind info
475 mono_cache_unwind_info (guint8 *unwind_info, guint32 unwind_info_len)
478 MonoUnwindInfo *info;
482 if (cached_info == NULL) {
483 cached_info_size = 16;
484 cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
487 for (i = 0; i < cached_info_next; ++i) {
488 MonoUnwindInfo *cached = cached_info [i];
490 if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
496 info = g_malloc (sizeof (MonoUnwindInfo) + unwind_info_len);
497 info->len = unwind_info_len;
498 memcpy (&info->info, unwind_info, unwind_info_len);
500 i = cached_info_next;
502 if (cached_info_next >= cached_info_size) {
503 MonoUnwindInfo **old_table, **new_table;
506 * Avoid freeing the old table so mono_get_cached_unwind_info ()
507 * doesn't need locks/hazard pointers.
510 old_table = cached_info;
511 new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
513 memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
515 mono_memory_barrier ();
517 cached_info = new_table;
519 cached_info_list = g_slist_prepend (cached_info_list, cached_info);
521 cached_info_size *= 2;
524 cached_info [cached_info_next ++] = info;
526 unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
533 * This function is signal safe.
536 mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
538 MonoUnwindInfo **table;
539 MonoUnwindInfo *info;
543 * This doesn't need any locks/hazard pointers,
544 * since new tables are copies of the old ones.
548 info = table [index];
550 *unwind_info_len = info->len;
557 * mono_unwind_get_dwarf_data_align:
559 * Return the data alignment used by the encoded unwind information.
562 mono_unwind_get_dwarf_data_align (void)
564 return DWARF_DATA_ALIGN;
568 * mono_unwind_get_dwarf_pc_reg:
570 * Return the dwarf register number of the register holding the ip of the
574 mono_unwind_get_dwarf_pc_reg (void)
580 decode_cie_op (guint8 *p, guint8 **endp)
585 case DW_CFA_advance_loc:
590 decode_uleb128 (p, &p);
597 decode_uleb128 (p, &p);
598 decode_uleb128 (p, &p);
600 case DW_CFA_def_cfa_offset:
601 decode_uleb128 (p, &p);
603 case DW_CFA_def_cfa_register:
604 decode_uleb128 (p, &p);
606 case DW_CFA_advance_loc4:
609 case DW_CFA_offset_extended_sf:
610 decode_uleb128 (p, &p);
611 decode_uleb128 (p, &p);
614 g_assert_not_reached ();
619 g_assert_not_reached ();
626 read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
630 switch (encoding & 0xf) {
631 case DW_EH_PE_sdata8:
635 case DW_EH_PE_sdata4:
640 g_assert_not_reached ();
650 * Decode the Language Specific Data Area generated by LLVM.
653 decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
655 gint32 ttype_offset, call_site_length;
656 gint32 ttype_encoding, call_site_encoding;
657 guint8 *ttype, *action_table, *call_site, *p;
661 * LLVM generates a c++ style LSDA, which can be decoded by looking at
662 * eh_personality.cc in gcc.
666 if (*p == DW_EH_PE_udata4) {
667 /* This is the modified LSDA generated by the LLVM mono branch */
668 guint32 mono_magic, version;
669 gint32 op, reg, offset;
672 mono_magic = decode_uleb128 (p, &p);
673 g_assert (mono_magic == 0x4d4fef4f);
674 version = decode_uleb128 (p, &p);
675 g_assert (version == 1);
677 /* 'this' location */
679 g_assert (op == DW_OP_bregx);
681 reg = decode_uleb128 (p, &p);
682 offset = decode_sleb128 (p, &p);
684 *this_reg = mono_dwarf_reg_to_hw_reg (reg);
685 *this_offset = offset;
688 g_assert (*p == DW_EH_PE_omit);
698 ttype_offset = decode_uleb128 (p, &p);
699 ttype = p + ttype_offset;
701 /* Read call-site table */
702 call_site_encoding = *p;
703 g_assert (call_site_encoding == DW_EH_PE_udata4);
705 call_site_length = decode_uleb128 (p, &p);
707 p += call_site_length;
710 /* Calculate the size of our table */
713 while (p < action_table) {
714 int block_start_offset, block_size, landing_pad, action_offset;
716 block_start_offset = read32 (p);
717 p += sizeof (gint32);
718 block_size = read32 (p);
719 p += sizeof (gint32);
720 landing_pad = read32 (p);
721 p += sizeof (gint32);
722 action_offset = decode_uleb128 (p, &p);
724 /* landing_pad == 0 means the region has no landing pad */
730 *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
731 *ex_info_len = ncall_sites;
735 *type_info = g_malloc0 (ncall_sites * sizeof (gpointer));
739 while (p < action_table) {
740 int block_start_offset, block_size, landing_pad, action_offset, type_offset;
741 guint8 *action, *tinfo;
743 block_start_offset = read32 (p);
744 p += sizeof (gint32);
745 block_size = read32 (p);
746 p += sizeof (gint32);
747 landing_pad = read32 (p);
748 p += sizeof (gint32);
749 action_offset = decode_uleb128 (p, &p);
754 action = action_table + action_offset - 1;
756 type_offset = decode_sleb128 (action, &action);
759 //printf ("BLOCK: %p-%p %p, %d\n", code + block_start_offset, code + block_start_offset + block_size, code + landing_pad, action_offset);
761 g_assert (ttype_offset);
763 if (ttype_encoding == DW_EH_PE_absptr) {
764 guint8 *ttype_entry = (ttype - (type_offset * sizeof (gpointer)));
765 tinfo = *(gpointer*)ttype_entry;
766 } else if (ttype_encoding == (DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
767 guint8 *ttype_entry = (ttype - (type_offset * 4));
768 gint32 offset = *(gint32*)ttype_entry;
769 guint8 *stub = ttype_entry + offset;
770 tinfo = *(gpointer*)stub;
771 } else if (ttype_encoding == (DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
772 guint8 *ttype_entry = (ttype - (type_offset * 4));
773 gint32 offset = *(gint32*)ttype_entry;
774 tinfo = ttype_entry + offset;
775 } else if (ttype_encoding == DW_EH_PE_udata4) {
776 /* Embedded directly */
777 guint8 *ttype_entry = (ttype - (type_offset * 4));
780 g_assert_not_reached ();
785 (*type_info) [i] = tinfo;
786 (*ex_info)[i].try_start = code + block_start_offset;
787 (*ex_info)[i].try_end = code + block_start_offset + block_size;
788 (*ex_info)[i].handler_start = code + landing_pad;
797 * mono_unwind_decode_fde:
799 * Decode a DWARF FDE entry, returning the unwind opcodes.
800 * If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
801 * only try_start, try_end and handler_start is set.
802 * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
806 mono_unwind_decode_fde (guint8 *fde, guint32 *out_len, guint32 *code_len, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
808 guint8 *p, *cie, *fde_current, *fde_aug = NULL, *code, *fde_cfi, *cie_cfi;
809 gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len, fde_data_len;
810 gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
811 gint32 i, cie_aug_len, buf_len;
814 gboolean has_fde_augmentation = FALSE;
817 * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
827 // FIXME: Endianess ?
828 fde_len = *(guint32*)p;
829 g_assert (fde_len != 0xffffffff && fde_len != 0);
831 cie_offset = *(guint32*)p;
832 cie = p - cie_offset;
838 cie_len = *(guint32*)p;
840 cie_id = *(guint32*)p;
841 g_assert (cie_id == 0);
844 g_assert (cie_version == 1);
846 cie_aug_str = (char*)p;
847 p += strlen (cie_aug_str) + 1;
848 code_align = decode_uleb128 (p, &p);
849 data_align = decode_sleb128 (p, &p);
850 return_reg = decode_uleb128 (p, &p);
851 if (strstr (cie_aug_str, "z")) {
855 cie_aug_len = decode_uleb128 (p, &p);
857 has_fde_augmentation = TRUE;
860 for (i = 0; cie_aug_str [i] != '\0'; ++i) {
861 switch (cie_aug_str [i]) {
867 read_encoded_val (p_encoding, p, &p);
870 g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
874 g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
878 g_assert_not_reached ();
888 /* Continue decoding FDE */
890 /* DW_EH_PE_sdata4|DW_EH_PE_pcrel encoding */
891 pc_begin = *(gint32*)p;
894 pc_range = *(guint32*)p;
896 if (has_fde_augmentation) {
897 aug_len = decode_uleb128 (p, &p);
904 fde_data_len = fde + 4 + fde_len - p;
907 *code_len = pc_range;
914 /* Decode FDE augmention */
919 /* sdata|pcrel encoding */
921 lsda_offset = read32 (fde_aug);
922 else if (aug_len == 8)
923 lsda_offset = *(gint64*)fde_aug;
925 g_assert_not_reached ();
926 if (lsda_offset != 0) {
927 lsda = fde_aug + lsda_offset;
929 decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
933 /* Make sure the FDE uses the same constants as we do */
934 g_assert (code_align == 1);
935 g_assert (data_align == DWARF_DATA_ALIGN);
936 g_assert (return_reg == DWARF_PC_REG);
938 buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
939 buf = g_malloc0 (buf_len);
943 while (p < cie + cie_len + 4) {
944 if (*p == DW_CFA_nop)
947 decode_cie_op (p, &p);
949 memcpy (buf + i, cie_cfi, p - cie_cfi);
953 while (p < fde + fde_len + 4) {
954 if (*p == DW_CFA_nop)
957 decode_cie_op (p, &p);
959 memcpy (buf + i, fde_cfi, p - fde_cfi);
961 g_assert (i <= buf_len);
965 return g_realloc (buf, i);
969 * mono_unwind_decode_mono_fde:
971 * Decode an FDE entry in the LLVM emitted mono EH frame.
972 * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
973 * only try_start, try_end and handler_start is set.
974 * info->type_info is set to a malloc-ed array containing the ttype table from the
978 mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
980 guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
981 int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
982 gint32 code_align, data_align, return_reg, pers_encoding;
984 memset (res, 0, sizeof (*res));
986 res->this_offset = -1;
988 /* fde points to data emitted by LLVM in DwarfException::EmitMonoEHFrame () */
993 aug_len = read32 (p);
1005 /* The LSDA is embedded directly into the FDE */
1008 decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
1013 code_align = decode_uleb128 (p, &p);
1014 data_align = decode_sleb128 (p, &p);
1015 return_reg = decode_uleb128 (p, &p);
1018 if (pers_encoding != DW_EH_PE_omit)
1019 read_encoded_val (pers_encoding, p, &p);
1023 /* Make sure the FDE uses the same constants as we do */
1024 g_assert (code_align == 1);
1025 g_assert (data_align == DWARF_DATA_ALIGN);
1026 g_assert (return_reg == DWARF_PC_REG);
1028 /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
1031 if (*p == DW_CFA_nop)
1034 decode_cie_op (p, &p);
1036 cie_cfi_len = p - cie_cfi;
1037 fde_cfi_len = (fde + fde_len - fde_cfi);
1039 buf = g_malloc0 (cie_cfi_len + fde_cfi_len);
1040 memcpy (buf, cie_cfi, cie_cfi_len);
1041 memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
1043 res->unw_info_len = cie_cfi_len + fde_cfi_len;
1044 res->unw_info = buf;
1048 * mono_unwind_get_cie_program:
1050 * Get the unwind bytecode for the DWARF CIE.
1053 mono_unwind_get_cie_program (void)
1055 #if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC)
1056 return mono_arch_get_cie_program ();