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https://github.com/tobast/libunwind-eh_elf.git
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8afc33ce9f
By default, the start_ip_offset in libunwind's table_entry struct is relative to the unw_dyn_info_t's segbase. This presents a problem for us in conjunction with using LLVM's MCJIT because it likes to spread text sections and the corresponding eh_frame sections quite far apart. This represents my attempt to support this use case in the simplest manner that is backwards compatible, by adding a new format kind (UNW_INFO_FORMAT_REMOTE_TABLE2) that indicates that the `start_ip_offset` should be interpreted as relative to `start_ip` rather than segbase.
214 lines
8.7 KiB
C
214 lines
8.7 KiB
C
/* libunwind - a platform-independent unwind library
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Copyright (C) 2002-2004 Hewlett-Packard Co
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Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
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This file is part of libunwind.
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Permission is hereby granted, free of charge, to any person obtaining
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a copy of this software and associated documentation files (the
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"Software"), to deal in the Software without restriction, including
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without limitation the rights to use, copy, modify, merge, publish,
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distribute, sublicense, and/or sell copies of the Software, and to
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permit persons to whom the Software is furnished to do so, subject to
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the following conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/* This file defines the runtime-support routines for dynamically
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generated code. Even though it is implemented as part of libunwind,
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it is logically separate from the interface to perform the actual
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unwinding. In particular, this interface is always used in the
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context of the unwind target, whereas the rest of the unwind API is
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used in context of the process that is doing the unwind (which may be
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a debugger running on another machine, for example).
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Note that the data-structures declared here server a dual purpose:
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when a program registers a dynamically generated procedure, it uses
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these structures directly. On the other hand, with remote-unwinding,
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the data-structures are read from the remote process's memory and
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translated into internalized versions. To facilitate remote-access,
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the following rules should be followed in declaring these structures:
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(1) Declare a member as a pointer only if the the information the
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member points to needs to be internalized as well (e.g., a
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string representing a procedure name should be declared as
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"const char *", but the instruction pointer should be declared
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as unw_word_t).
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(2) Provide sufficient padding to ensure that no implicit padding
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will be needed on any of the supported target architectures. For
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the time being, padding data structures with the assumption that
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sizeof (unw_word_t) == 8 should be sufficient. (Note: it's not
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impossible to internalize structures with internal padding, but
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it does make the process a bit harder).
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(3) Don't declare members that contain bitfields or floating-point
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values.
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(4) Don't declare members with enumeration types. Declare them as
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int32_t instead. */
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typedef enum
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{
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UNW_DYN_STOP = 0, /* end-of-unwind-info marker */
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UNW_DYN_SAVE_REG, /* save register to another register */
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UNW_DYN_SPILL_FP_REL, /* frame-pointer-relative register spill */
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UNW_DYN_SPILL_SP_REL, /* stack-pointer-relative register spill */
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UNW_DYN_ADD, /* add constant value to a register */
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UNW_DYN_POP_FRAMES, /* drop one or more stack frames */
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UNW_DYN_LABEL_STATE, /* name the current state */
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UNW_DYN_COPY_STATE, /* set the region's entry-state */
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UNW_DYN_ALIAS /* get unwind info from an alias */
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}
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unw_dyn_operation_t;
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typedef enum
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{
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UNW_INFO_FORMAT_DYNAMIC, /* unw_dyn_proc_info_t */
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UNW_INFO_FORMAT_TABLE, /* unw_dyn_table_t */
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UNW_INFO_FORMAT_REMOTE_TABLE, /* unw_dyn_remote_table_t */
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UNW_INFO_FORMAT_ARM_EXIDX, /* ARM specific unwind info */
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UNW_INFO_FORMAT_IP_OFFSET, /* Like UNW_INFO_FORMAT_REMOTE_TABLE, but
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table entries are considered
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relative to di->start_ip, rather
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than di->segbase */
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}
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unw_dyn_info_format_t;
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typedef struct unw_dyn_op
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{
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int8_t tag; /* what operation? */
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int8_t qp; /* qualifying predicate register */
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int16_t reg; /* what register */
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int32_t when; /* when does it take effect? */
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unw_word_t val; /* auxiliary value */
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}
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unw_dyn_op_t;
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typedef struct unw_dyn_region_info
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{
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struct unw_dyn_region_info *next; /* linked list of regions */
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int32_t insn_count; /* region length (# of instructions) */
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uint32_t op_count; /* length of op-array */
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unw_dyn_op_t op[1]; /* variable-length op-array */
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}
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unw_dyn_region_info_t;
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typedef struct unw_dyn_proc_info
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{
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unw_word_t name_ptr; /* address of human-readable procedure name */
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unw_word_t handler; /* address of personality routine */
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uint32_t flags;
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int32_t pad0;
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unw_dyn_region_info_t *regions;
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}
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unw_dyn_proc_info_t;
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typedef struct unw_dyn_table_info
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{
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unw_word_t name_ptr; /* addr. of table name (e.g., library name) */
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unw_word_t segbase; /* segment base */
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unw_word_t table_len; /* must be a multiple of sizeof(unw_word_t)! */
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unw_word_t *table_data;
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}
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unw_dyn_table_info_t;
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typedef struct unw_dyn_remote_table_info
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{
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unw_word_t name_ptr; /* addr. of table name (e.g., library name) */
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unw_word_t segbase; /* segment base */
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unw_word_t table_len; /* must be a multiple of sizeof(unw_word_t)! */
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unw_word_t table_data;
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}
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unw_dyn_remote_table_info_t;
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typedef struct unw_dyn_info
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{
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/* doubly-linked list of dyn-info structures: */
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struct unw_dyn_info *next;
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struct unw_dyn_info *prev;
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unw_word_t start_ip; /* first IP covered by this entry */
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unw_word_t end_ip; /* first IP NOT covered by this entry */
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unw_word_t gp; /* global-pointer in effect for this entry */
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int32_t format; /* real type: unw_dyn_info_format_t */
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int32_t pad;
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union
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{
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unw_dyn_proc_info_t pi;
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unw_dyn_table_info_t ti;
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unw_dyn_remote_table_info_t rti;
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}
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u;
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}
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unw_dyn_info_t;
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typedef struct unw_dyn_info_list
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{
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uint32_t version;
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uint32_t generation;
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unw_dyn_info_t *first;
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}
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unw_dyn_info_list_t;
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/* Return the size (in bytes) of an unw_dyn_region_info_t structure that can
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hold OP_COUNT ops. */
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#define _U_dyn_region_info_size(op_count) \
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((char *) (((unw_dyn_region_info_t *) NULL)->op + (op_count)) \
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- (char *) NULL)
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/* Register the unwind info for a single procedure.
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This routine is NOT signal-safe. */
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extern void _U_dyn_register (unw_dyn_info_t *);
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/* Cancel the unwind info for a single procedure.
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This routine is NOT signal-safe. */
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extern void _U_dyn_cancel (unw_dyn_info_t *);
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/* Convenience routines. */
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#define _U_dyn_op(_tag, _qp, _when, _reg, _val) \
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((unw_dyn_op_t) { (_tag), (_qp), (_reg), (_when), (_val) })
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#define _U_dyn_op_save_reg(op, qp, when, reg, dst) \
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(*(op) = _U_dyn_op (UNW_DYN_SAVE_REG, (qp), (when), (reg), (dst)))
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#define _U_dyn_op_spill_fp_rel(op, qp, when, reg, offset) \
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(*(op) = _U_dyn_op (UNW_DYN_SPILL_FP_REL, (qp), (when), (reg), \
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(offset)))
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#define _U_dyn_op_spill_sp_rel(op, qp, when, reg, offset) \
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(*(op) = _U_dyn_op (UNW_DYN_SPILL_SP_REL, (qp), (when), (reg), \
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(offset)))
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#define _U_dyn_op_add(op, qp, when, reg, value) \
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(*(op) = _U_dyn_op (UNW_DYN_ADD, (qp), (when), (reg), (value)))
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#define _U_dyn_op_pop_frames(op, qp, when, num_frames) \
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(*(op) = _U_dyn_op (UNW_DYN_POP_FRAMES, (qp), (when), 0, (num_frames)))
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#define _U_dyn_op_label_state(op, label) \
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(*(op) = _U_dyn_op (UNW_DYN_LABEL_STATE, _U_QP_TRUE, -1, 0, (label)))
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#define _U_dyn_op_copy_state(op, label) \
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(*(op) = _U_dyn_op (UNW_DYN_COPY_STATE, _U_QP_TRUE, -1, 0, (label)))
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#define _U_dyn_op_alias(op, qp, when, addr) \
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(*(op) = _U_dyn_op (UNW_DYN_ALIAS, (qp), (when), 0, (addr)))
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#define _U_dyn_op_stop(op) \
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(*(op) = _U_dyn_op (UNW_DYN_STOP, _U_QP_TRUE, -1, 0, 0))
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/* The target-dependent qualifying predicate which is always TRUE. On
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IA-64, that's p0 (0), on non-predicated architectures, the value is
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ignored. */
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#define _U_QP_TRUE _U_TDEP_QP_TRUE
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