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-rw-r--r--3rdparty/libbacktrace/dwarf.c3126
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diff --git a/3rdparty/libbacktrace/dwarf.c b/3rdparty/libbacktrace/dwarf.c
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+++ b/3rdparty/libbacktrace/dwarf.c
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+/* dwarf.c -- Get file/line information from DWARF for backtraces.
+ Copyright (C) 2012-2018 Free Software Foundation, Inc.
+ Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+ (1) Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ (2) Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+
+ (3) The name of the author may not be used to
+ endorse or promote products derived from this software without
+ specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE. */
+
+#include "config.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "backtrace.h"
+#include "internal.h"
+
+/* DWARF constants. */
+
+enum dwarf_tag {
+ DW_TAG_entry_point = 0x3,
+ DW_TAG_compile_unit = 0x11,
+ DW_TAG_inlined_subroutine = 0x1d,
+ DW_TAG_subprogram = 0x2e,
+};
+
+enum dwarf_form {
+ DW_FORM_addr = 0x1,
+ DW_FORM_block2 = 0x3,
+ DW_FORM_block4 = 0x4,
+ DW_FORM_data2 = 0x5,
+ DW_FORM_data4 = 0x6,
+ DW_FORM_data8 = 0x07,
+ DW_FORM_string = 0x08,
+ DW_FORM_block = 0x09,
+ DW_FORM_block1 = 0x0a,
+ DW_FORM_data1 = 0x0b,
+ DW_FORM_flag = 0x0c,
+ DW_FORM_sdata = 0x0d,
+ DW_FORM_strp = 0x0e,
+ DW_FORM_udata = 0x0f,
+ DW_FORM_ref_addr = 0x10,
+ DW_FORM_ref1 = 0x11,
+ DW_FORM_ref2 = 0x12,
+ DW_FORM_ref4 = 0x13,
+ DW_FORM_ref8 = 0x14,
+ DW_FORM_ref_udata = 0x15,
+ DW_FORM_indirect = 0x16,
+ DW_FORM_sec_offset = 0x17,
+ DW_FORM_exprloc = 0x18,
+ DW_FORM_flag_present = 0x19,
+ DW_FORM_ref_sig8 = 0x20,
+ DW_FORM_GNU_addr_index = 0x1f01,
+ DW_FORM_GNU_str_index = 0x1f02,
+ DW_FORM_GNU_ref_alt = 0x1f20,
+ DW_FORM_GNU_strp_alt = 0x1f21,
+};
+
+enum dwarf_attribute {
+ DW_AT_name = 0x3,
+ DW_AT_stmt_list = 0x10,
+ DW_AT_low_pc = 0x11,
+ DW_AT_high_pc = 0x12,
+ DW_AT_comp_dir = 0x1b,
+ DW_AT_abstract_origin = 0x31,
+ DW_AT_specification = 0x47,
+ DW_AT_ranges = 0x55,
+ DW_AT_call_file = 0x58,
+ DW_AT_call_line = 0x59,
+ DW_AT_linkage_name = 0x6e,
+ DW_AT_MIPS_linkage_name = 0x2007,
+};
+
+enum dwarf_line_number_op {
+ DW_LNS_extended_op = 0x0,
+ DW_LNS_copy = 0x1,
+ DW_LNS_advance_pc = 0x2,
+ DW_LNS_advance_line = 0x3,
+ DW_LNS_set_file = 0x4,
+ DW_LNS_set_column = 0x5,
+ DW_LNS_negate_stmt = 0x6,
+ DW_LNS_set_basic_block = 0x7,
+ DW_LNS_const_add_pc = 0x8,
+ DW_LNS_fixed_advance_pc = 0x9,
+ DW_LNS_set_prologue_end = 0xa,
+ DW_LNS_set_epilogue_begin = 0xb,
+ DW_LNS_set_isa = 0xc,
+};
+
+enum dwarf_extedned_line_number_op {
+ DW_LNE_end_sequence = 0x1,
+ DW_LNE_set_address = 0x2,
+ DW_LNE_define_file = 0x3,
+ DW_LNE_set_discriminator = 0x4,
+};
+
+#if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
+# define IS_DIR_SEPARATOR(c) ((c) == '/' || (c) == '\\')
+#define HAS_DRIVE_SPEC(f) ((f)[0] && (f)[1] == ':')
+# define IS_ABSOLUTE_PATH(f) (IS_DIR_SEPARATOR(f[0]) || HAS_DRIVE_SPEC(f))
+#else
+# define IS_DIR_SEPARATOR(c) ((c) == '/')
+# define IS_ABSOLUTE_PATH(f) IS_DIR_SEPARATOR(f[0])
+#endif
+
+#if !defined(HAVE_DECL_STRNLEN) || !HAVE_DECL_STRNLEN
+
+/* If strnlen is not declared, provide our own version. */
+
+static size_t
+xstrnlen (const char *s, size_t maxlen)
+{
+ size_t i;
+
+ for (i = 0; i < maxlen; ++i)
+ if (s[i] == '\0')
+ break;
+ return i;
+}
+
+#define strnlen xstrnlen
+
+#endif
+
+/* A buffer to read DWARF info. */
+
+struct dwarf_buf
+{
+ /* Buffer name for error messages. */
+ const char *name;
+ /* Start of the buffer. */
+ const unsigned char *start;
+ /* Next byte to read. */
+ const unsigned char *buf;
+ /* The number of bytes remaining. */
+ size_t left;
+ /* Whether the data is big-endian. */
+ int is_bigendian;
+ /* Error callback routine. */
+ backtrace_error_callback error_callback;
+ /* Data for error_callback. */
+ void *data;
+ /* Non-zero if we've reported an underflow error. */
+ int reported_underflow;
+};
+
+/* A single attribute in a DWARF abbreviation. */
+
+struct attr
+{
+ /* The attribute name. */
+ enum dwarf_attribute name;
+ /* The attribute form. */
+ enum dwarf_form form;
+};
+
+/* A single DWARF abbreviation. */
+
+struct abbrev
+{
+ /* The abbrev code--the number used to refer to the abbrev. */
+ uint64_t code;
+ /* The entry tag. */
+ enum dwarf_tag tag;
+ /* Non-zero if this abbrev has child entries. */
+ int has_children;
+ /* The number of attributes. */
+ size_t num_attrs;
+ /* The attributes. */
+ struct attr *attrs;
+};
+
+/* The DWARF abbreviations for a compilation unit. This structure
+ only exists while reading the compilation unit. Most DWARF readers
+ seem to a hash table to map abbrev ID's to abbrev entries.
+ However, we primarily care about GCC, and GCC simply issues ID's in
+ numerical order starting at 1. So we simply keep a sorted vector,
+ and try to just look up the code. */
+
+struct abbrevs
+{
+ /* The number of abbrevs in the vector. */
+ size_t num_abbrevs;
+ /* The abbrevs, sorted by the code field. */
+ struct abbrev *abbrevs;
+};
+
+/* The different kinds of attribute values. */
+
+enum attr_val_encoding
+{
+ /* An address. */
+ ATTR_VAL_ADDRESS,
+ /* A unsigned integer. */
+ ATTR_VAL_UINT,
+ /* A sigd integer. */
+ ATTR_VAL_SINT,
+ /* A string. */
+ ATTR_VAL_STRING,
+ /* An offset to other data in the containing unit. */
+ ATTR_VAL_REF_UNIT,
+ /* An offset to other data within the .dwarf_info section. */
+ ATTR_VAL_REF_INFO,
+ /* An offset to data in some other section. */
+ ATTR_VAL_REF_SECTION,
+ /* A type signature. */
+ ATTR_VAL_REF_TYPE,
+ /* A block of data (not represented). */
+ ATTR_VAL_BLOCK,
+ /* An expression (not represented). */
+ ATTR_VAL_EXPR,
+};
+
+/* An attribute value. */
+
+struct attr_val
+{
+ /* How the value is stored in the field u. */
+ enum attr_val_encoding encoding;
+ union
+ {
+ /* ATTR_VAL_ADDRESS, ATTR_VAL_UINT, ATTR_VAL_REF*. */
+ uint64_t uint;
+ /* ATTR_VAL_SINT. */
+ int64_t sint;
+ /* ATTR_VAL_STRING. */
+ const char *string;
+ /* ATTR_VAL_BLOCK not stored. */
+ } u;
+};
+
+/* The line number program header. */
+
+struct line_header
+{
+ /* The version of the line number information. */
+ int version;
+ /* The minimum instruction length. */
+ unsigned int min_insn_len;
+ /* The maximum number of ops per instruction. */
+ unsigned int max_ops_per_insn;
+ /* The line base for special opcodes. */
+ int line_base;
+ /* The line range for special opcodes. */
+ unsigned int line_range;
+ /* The opcode base--the first special opcode. */
+ unsigned int opcode_base;
+ /* Opcode lengths, indexed by opcode - 1. */
+ const unsigned char *opcode_lengths;
+ /* The number of directory entries. */
+ size_t dirs_count;
+ /* The directory entries. */
+ const char **dirs;
+ /* The number of filenames. */
+ size_t filenames_count;
+ /* The filenames. */
+ const char **filenames;
+};
+
+/* Map a single PC value to a file/line. We will keep a vector of
+ these sorted by PC value. Each file/line will be correct from the
+ PC up to the PC of the next entry if there is one. We allocate one
+ extra entry at the end so that we can use bsearch. */
+
+struct line
+{
+ /* PC. */
+ uintptr_t pc;
+ /* File name. Many entries in the array are expected to point to
+ the same file name. */
+ const char *filename;
+ /* Line number. */
+ int lineno;
+ /* Index of the object in the original array read from the DWARF
+ section, before it has been sorted. The index makes it possible
+ to use Quicksort and maintain stability. */
+ int idx;
+};
+
+/* A growable vector of line number information. This is used while
+ reading the line numbers. */
+
+struct line_vector
+{
+ /* Memory. This is an array of struct line. */
+ struct backtrace_vector vec;
+ /* Number of valid mappings. */
+ size_t count;
+};
+
+/* A function described in the debug info. */
+
+struct function
+{
+ /* The name of the function. */
+ const char *name;
+ /* If this is an inlined function, the filename of the call
+ site. */
+ const char *caller_filename;
+ /* If this is an inlined function, the line number of the call
+ site. */
+ int caller_lineno;
+ /* Map PC ranges to inlined functions. */
+ struct function_addrs *function_addrs;
+ size_t function_addrs_count;
+};
+
+/* An address range for a function. This maps a PC value to a
+ specific function. */
+
+struct function_addrs
+{
+ /* Range is LOW <= PC < HIGH. */
+ uint64_t low;
+ uint64_t high;
+ /* Function for this address range. */
+ struct function *function;
+};
+
+/* A growable vector of function address ranges. */
+
+struct function_vector
+{
+ /* Memory. This is an array of struct function_addrs. */
+ struct backtrace_vector vec;
+ /* Number of address ranges present. */
+ size_t count;
+};
+
+/* A DWARF compilation unit. This only holds the information we need
+ to map a PC to a file and line. */
+
+struct unit
+{
+ /* The first entry for this compilation unit. */
+ const unsigned char *unit_data;
+ /* The length of the data for this compilation unit. */
+ size_t unit_data_len;
+ /* The offset of UNIT_DATA from the start of the information for
+ this compilation unit. */
+ size_t unit_data_offset;
+ /* DWARF version. */
+ int version;
+ /* Whether unit is DWARF64. */
+ int is_dwarf64;
+ /* Address size. */
+ int addrsize;
+ /* Offset into line number information. */
+ off_t lineoff;
+ /* Primary source file. */
+ const char *filename;
+ /* Compilation command working directory. */
+ const char *comp_dir;
+ /* Absolute file name, only set if needed. */
+ const char *abs_filename;
+ /* The abbreviations for this unit. */
+ struct abbrevs abbrevs;
+
+ /* The fields above this point are read in during initialization and
+ may be accessed freely. The fields below this point are read in
+ as needed, and therefore require care, as different threads may
+ try to initialize them simultaneously. */
+
+ /* PC to line number mapping. This is NULL if the values have not
+ been read. This is (struct line *) -1 if there was an error
+ reading the values. */
+ struct line *lines;
+ /* Number of entries in lines. */
+ size_t lines_count;
+ /* PC ranges to function. */
+ struct function_addrs *function_addrs;
+ size_t function_addrs_count;
+};
+
+/* An address range for a compilation unit. This maps a PC value to a
+ specific compilation unit. Note that we invert the representation
+ in DWARF: instead of listing the units and attaching a list of
+ ranges, we list the ranges and have each one point to the unit.
+ This lets us do a binary search to find the unit. */
+
+struct unit_addrs
+{
+ /* Range is LOW <= PC < HIGH. */
+ uint64_t low;
+ uint64_t high;
+ /* Compilation unit for this address range. */
+ struct unit *u;
+};
+
+/* A growable vector of compilation unit address ranges. */
+
+struct unit_addrs_vector
+{
+ /* Memory. This is an array of struct unit_addrs. */
+ struct backtrace_vector vec;
+ /* Number of address ranges present. */
+ size_t count;
+};
+
+/* The information we need to map a PC to a file and line. */
+
+struct dwarf_data
+{
+ /* The data for the next file we know about. */
+ struct dwarf_data *next;
+ /* The base address for this file. */
+ uintptr_t base_address;
+ /* A sorted list of address ranges. */
+ struct unit_addrs *addrs;
+ /* Number of address ranges in list. */
+ size_t addrs_count;
+ /* The unparsed .debug_info section. */
+ const unsigned char *dwarf_info;
+ size_t dwarf_info_size;
+ /* The unparsed .debug_line section. */
+ const unsigned char *dwarf_line;
+ size_t dwarf_line_size;
+ /* The unparsed .debug_ranges section. */
+ const unsigned char *dwarf_ranges;
+ size_t dwarf_ranges_size;
+ /* The unparsed .debug_str section. */
+ const unsigned char *dwarf_str;
+ size_t dwarf_str_size;
+ /* Whether the data is big-endian or not. */
+ int is_bigendian;
+ /* A vector used for function addresses. We keep this here so that
+ we can grow the vector as we read more functions. */
+ struct function_vector fvec;
+};
+
+/* Report an error for a DWARF buffer. */
+
+static void
+dwarf_buf_error (struct dwarf_buf *buf, const char *msg)
+{
+ char b[200];
+
+ snprintf (b, sizeof b, "%s in %s at %d",
+ msg, buf->name, (int) (buf->buf - buf->start));
+ buf->error_callback (buf->data, b, 0);
+}
+
+/* Require at least COUNT bytes in BUF. Return 1 if all is well, 0 on
+ error. */
+
+static int
+require (struct dwarf_buf *buf, size_t count)
+{
+ if (buf->left >= count)
+ return 1;
+
+ if (!buf->reported_underflow)
+ {
+ dwarf_buf_error (buf, "DWARF underflow");
+ buf->reported_underflow = 1;
+ }
+
+ return 0;
+}
+
+/* Advance COUNT bytes in BUF. Return 1 if all is well, 0 on
+ error. */
+
+static int
+advance (struct dwarf_buf *buf, size_t count)
+{
+ if (!require (buf, count))
+ return 0;
+ buf->buf += count;
+ buf->left -= count;
+ return 1;
+}
+
+/* Read one byte from BUF and advance 1 byte. */
+
+static unsigned char
+read_byte (struct dwarf_buf *buf)
+{
+ const unsigned char *p = buf->buf;
+
+ if (!advance (buf, 1))
+ return 0;
+ return p[0];
+}
+
+/* Read a signed char from BUF and advance 1 byte. */
+
+static signed char
+read_sbyte (struct dwarf_buf *buf)
+{
+ const unsigned char *p = buf->buf;
+
+ if (!advance (buf, 1))
+ return 0;
+ return (*p ^ 0x80) - 0x80;
+}
+
+/* Read a uint16 from BUF and advance 2 bytes. */
+
+static uint16_t
+read_uint16 (struct dwarf_buf *buf)
+{
+ const unsigned char *p = buf->buf;
+
+ if (!advance (buf, 2))
+ return 0;
+ if (buf->is_bigendian)
+ return ((uint16_t) p[0] << 8) | (uint16_t) p[1];
+ else
+ return ((uint16_t) p[1] << 8) | (uint16_t) p[0];
+}
+
+/* Read a uint32 from BUF and advance 4 bytes. */
+
+static uint32_t
+read_uint32 (struct dwarf_buf *buf)
+{
+ const unsigned char *p = buf->buf;
+
+ if (!advance (buf, 4))
+ return 0;
+ if (buf->is_bigendian)
+ return (((uint32_t) p[0] << 24) | ((uint32_t) p[1] << 16)
+ | ((uint32_t) p[2] << 8) | (uint32_t) p[3]);
+ else
+ return (((uint32_t) p[3] << 24) | ((uint32_t) p[2] << 16)
+ | ((uint32_t) p[1] << 8) | (uint32_t) p[0]);
+}
+
+/* Read a uint64 from BUF and advance 8 bytes. */
+
+static uint64_t
+read_uint64 (struct dwarf_buf *buf)
+{
+ const unsigned char *p = buf->buf;
+
+ if (!advance (buf, 8))
+ return 0;
+ if (buf->is_bigendian)
+ return (((uint64_t) p[0] << 56) | ((uint64_t) p[1] << 48)
+ | ((uint64_t) p[2] << 40) | ((uint64_t) p[3] << 32)
+ | ((uint64_t) p[4] << 24) | ((uint64_t) p[5] << 16)
+ | ((uint64_t) p[6] << 8) | (uint64_t) p[7]);
+ else
+ return (((uint64_t) p[7] << 56) | ((uint64_t) p[6] << 48)
+ | ((uint64_t) p[5] << 40) | ((uint64_t) p[4] << 32)
+ | ((uint64_t) p[3] << 24) | ((uint64_t) p[2] << 16)
+ | ((uint64_t) p[1] << 8) | (uint64_t) p[0]);
+}
+
+/* Read an offset from BUF and advance the appropriate number of
+ bytes. */
+
+static uint64_t
+read_offset (struct dwarf_buf *buf, int is_dwarf64)
+{
+ if (is_dwarf64)
+ return read_uint64 (buf);
+ else
+ return read_uint32 (buf);
+}
+
+/* Read an address from BUF and advance the appropriate number of
+ bytes. */
+
+static uint64_t
+read_address (struct dwarf_buf *buf, int addrsize)
+{
+ switch (addrsize)
+ {
+ case 1:
+ return read_byte (buf);
+ case 2:
+ return read_uint16 (buf);
+ case 4:
+ return read_uint32 (buf);
+ case 8:
+ return read_uint64 (buf);
+ default:
+ dwarf_buf_error (buf, "unrecognized address size");
+ return 0;
+ }
+}
+
+/* Return whether a value is the highest possible address, given the
+ address size. */
+
+static int
+is_highest_address (uint64_t address, int addrsize)
+{
+ switch (addrsize)
+ {
+ case 1:
+ return address == (unsigned char) -1;
+ case 2:
+ return address == (uint16_t) -1;
+ case 4:
+ return address == (uint32_t) -1;
+ case 8:
+ return address == (uint64_t) -1;
+ default:
+ return 0;
+ }
+}
+
+/* Read an unsigned LEB128 number. */
+
+static uint64_t
+read_uleb128 (struct dwarf_buf *buf)
+{
+ uint64_t ret;
+ unsigned int shift;
+ int overflow;
+ unsigned char b;
+
+ ret = 0;
+ shift = 0;
+ overflow = 0;
+ do
+ {
+ const unsigned char *p;
+
+ p = buf->buf;
+ if (!advance (buf, 1))
+ return 0;
+ b = *p;
+ if (shift < 64)
+ ret |= ((uint64_t) (b & 0x7f)) << shift;
+ else if (!overflow)
+ {
+ dwarf_buf_error (buf, "LEB128 overflows uint64_t");
+ overflow = 1;
+ }
+ shift += 7;
+ }
+ while ((b & 0x80) != 0);
+
+ return ret;
+}
+
+/* Read a signed LEB128 number. */
+
+static int64_t
+read_sleb128 (struct dwarf_buf *buf)
+{
+ uint64_t val;
+ unsigned int shift;
+ int overflow;
+ unsigned char b;
+
+ val = 0;
+ shift = 0;
+ overflow = 0;
+ do
+ {
+ const unsigned char *p;
+
+ p = buf->buf;
+ if (!advance (buf, 1))
+ return 0;
+ b = *p;
+ if (shift < 64)
+ val |= ((uint64_t) (b & 0x7f)) << shift;
+ else if (!overflow)
+ {
+ dwarf_buf_error (buf, "signed LEB128 overflows uint64_t");
+ overflow = 1;
+ }
+ shift += 7;
+ }
+ while ((b & 0x80) != 0);
+
+ if ((b & 0x40) != 0 && shift < 64)
+ val |= ((uint64_t) -1) << shift;
+
+ return (int64_t) val;
+}
+
+/* Return the length of an LEB128 number. */
+
+static size_t
+leb128_len (const unsigned char *p)
+{
+ size_t ret;
+
+ ret = 1;
+ while ((*p & 0x80) != 0)
+ {
+ ++p;
+ ++ret;
+ }
+ return ret;
+}
+
+/* Free an abbreviations structure. */
+
+static void
+free_abbrevs (struct backtrace_state *state, struct abbrevs *abbrevs,
+ backtrace_error_callback error_callback, void *data)
+{
+ size_t i;
+
+ for (i = 0; i < abbrevs->num_abbrevs; ++i)
+ backtrace_free (state, abbrevs->abbrevs[i].attrs,
+ abbrevs->abbrevs[i].num_attrs * sizeof (struct attr),
+ error_callback, data);
+ backtrace_free (state, abbrevs->abbrevs,
+ abbrevs->num_abbrevs * sizeof (struct abbrev),
+ error_callback, data);
+ abbrevs->num_abbrevs = 0;
+ abbrevs->abbrevs = NULL;
+}
+
+/* Read an attribute value. Returns 1 on success, 0 on failure. If
+ the value can be represented as a uint64_t, sets *VAL and sets
+ *IS_VALID to 1. We don't try to store the value of other attribute
+ forms, because we don't care about them. */
+
+static int
+read_attribute (enum dwarf_form form, struct dwarf_buf *buf,
+ int is_dwarf64, int version, int addrsize,
+ const unsigned char *dwarf_str, size_t dwarf_str_size,
+ struct attr_val *val)
+{
+ /* Avoid warnings about val.u.FIELD may be used uninitialized if
+ this function is inlined. The warnings aren't valid but can
+ occur because the different fields are set and used
+ conditionally. */
+ memset (val, 0, sizeof *val);
+
+ switch (form)
+ {
+ case DW_FORM_addr:
+ val->encoding = ATTR_VAL_ADDRESS;
+ val->u.uint = read_address (buf, addrsize);
+ return 1;
+ case DW_FORM_block2:
+ val->encoding = ATTR_VAL_BLOCK;
+ return advance (buf, read_uint16 (buf));
+ case DW_FORM_block4:
+ val->encoding = ATTR_VAL_BLOCK;
+ return advance (buf, read_uint32 (buf));
+ case DW_FORM_data2:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_uint16 (buf);
+ return 1;
+ case DW_FORM_data4:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_uint32 (buf);
+ return 1;
+ case DW_FORM_data8:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_uint64 (buf);
+ return 1;
+ case DW_FORM_string:
+ val->encoding = ATTR_VAL_STRING;
+ val->u.string = (const char *) buf->buf;
+ return advance (buf, strnlen ((const char *) buf->buf, buf->left) + 1);
+ case DW_FORM_block:
+ val->encoding = ATTR_VAL_BLOCK;
+ return advance (buf, read_uleb128 (buf));
+ case DW_FORM_block1:
+ val->encoding = ATTR_VAL_BLOCK;
+ return advance (buf, read_byte (buf));
+ case DW_FORM_data1:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_byte (buf);
+ return 1;
+ case DW_FORM_flag:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_byte (buf);
+ return 1;
+ case DW_FORM_sdata:
+ val->encoding = ATTR_VAL_SINT;
+ val->u.sint = read_sleb128 (buf);
+ return 1;
+ case DW_FORM_strp:
+ {
+ uint64_t offset;
+
+ offset = read_offset (buf, is_dwarf64);
+ if (offset >= dwarf_str_size)
+ {
+ dwarf_buf_error (buf, "DW_FORM_strp out of range");
+ return 0;
+ }
+ val->encoding = ATTR_VAL_STRING;
+ val->u.string = (const char *) dwarf_str + offset;
+ return 1;
+ }
+ case DW_FORM_udata:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = read_uleb128 (buf);
+ return 1;
+ case DW_FORM_ref_addr:
+ val->encoding = ATTR_VAL_REF_INFO;
+ if (version == 2)
+ val->u.uint = read_address (buf, addrsize);
+ else
+ val->u.uint = read_offset (buf, is_dwarf64);
+ return 1;
+ case DW_FORM_ref1:
+ val->encoding = ATTR_VAL_REF_UNIT;
+ val->u.uint = read_byte (buf);
+ return 1;
+ case DW_FORM_ref2:
+ val->encoding = ATTR_VAL_REF_UNIT;
+ val->u.uint = read_uint16 (buf);
+ return 1;
+ case DW_FORM_ref4:
+ val->encoding = ATTR_VAL_REF_UNIT;
+ val->u.uint = read_uint32 (buf);
+ return 1;
+ case DW_FORM_ref8:
+ val->encoding = ATTR_VAL_REF_UNIT;
+ val->u.uint = read_uint64 (buf);
+ return 1;
+ case DW_FORM_ref_udata:
+ val->encoding = ATTR_VAL_REF_UNIT;
+ val->u.uint = read_uleb128 (buf);
+ return 1;
+ case DW_FORM_indirect:
+ {
+ uint64_t form1;
+
+ form1 = read_uleb128 (buf);
+ return read_attribute ((enum dwarf_form) form1, buf, is_dwarf64,
+ version, addrsize, dwarf_str, dwarf_str_size,
+ val);
+ }
+ case DW_FORM_sec_offset:
+ val->encoding = ATTR_VAL_REF_SECTION;
+ val->u.uint = read_offset (buf, is_dwarf64);
+ return 1;
+ case DW_FORM_exprloc:
+ val->encoding = ATTR_VAL_EXPR;
+ return advance (buf, read_uleb128 (buf));
+ case DW_FORM_flag_present:
+ val->encoding = ATTR_VAL_UINT;
+ val->u.uint = 1;
+ return 1;
+ case DW_FORM_ref_sig8:
+ val->encoding = ATTR_VAL_REF_TYPE;
+ val->u.uint = read_uint64 (buf);
+ return 1;
+ case DW_FORM_GNU_addr_index:
+ val->encoding = ATTR_VAL_REF_SECTION;
+ val->u.uint = read_uleb128 (buf);
+ return 1;
+ case DW_FORM_GNU_str_index:
+ val->encoding = ATTR_VAL_REF_SECTION;
+ val->u.uint = read_uleb128 (buf);
+ return 1;
+ case DW_FORM_GNU_ref_alt:
+ val->encoding = ATTR_VAL_REF_SECTION;
+ val->u.uint = read_offset (buf, is_dwarf64);
+ return 1;
+ case DW_FORM_GNU_strp_alt:
+ val->encoding = ATTR_VAL_REF_SECTION;
+ val->u.uint = read_offset (buf, is_dwarf64);
+ return 1;
+ default:
+ dwarf_buf_error (buf, "unrecognized DWARF form");
+ return 0;
+ }
+}
+
+/* Compare function_addrs for qsort. When ranges are nested, make the
+ smallest one sort last. */
+
+static int
+function_addrs_compare (const void *v1, const void *v2)
+{
+ const struct function_addrs *a1 = (const struct function_addrs *) v1;
+ const struct function_addrs *a2 = (const struct function_addrs *) v2;
+
+ if (a1->low < a2->low)
+ return -1;
+ if (a1->low > a2->low)
+ return 1;
+ if (a1->high < a2->high)
+ return 1;
+ if (a1->high > a2->high)
+ return -1;
+ return strcmp (a1->function->name, a2->function->name);
+}
+
+/* Compare a PC against a function_addrs for bsearch. Note that if
+ there are multiple ranges containing PC, which one will be returned
+ is unpredictable. We compensate for that in dwarf_fileline. */
+
+static int
+function_addrs_search (const void *vkey, const void *ventry)
+{
+ const uintptr_t *key = (const uintptr_t *) vkey;
+ const struct function_addrs *entry = (const struct function_addrs *) ventry;
+ uintptr_t pc;
+
+ pc = *key;
+ if (pc < entry->low)
+ return -1;
+ else if (pc >= entry->high)
+ return 1;
+ else
+ return 0;
+}
+
+/* Add a new compilation unit address range to a vector. Returns 1 on
+ success, 0 on failure. */
+
+static int
+add_unit_addr (struct backtrace_state *state, uintptr_t base_address,
+ struct unit_addrs addrs,
+ backtrace_error_callback error_callback, void *data,
+ struct unit_addrs_vector *vec)
+{
+ struct unit_addrs *p;
+
+ /* Add in the base address of the module here, so that we can look
+ up the PC directly. */
+ addrs.low += base_address;
+ addrs.high += base_address;
+
+ /* Try to merge with the last entry. */
+ if (vec->count > 0)
+ {
+ p = (struct unit_addrs *) vec->vec.base + (vec->count - 1);
+ if ((addrs.low == p->high || addrs.low == p->high + 1)
+ && addrs.u == p->u)
+ {
+ if (addrs.high > p->high)
+ p->high = addrs.high;
+ return 1;
+ }
+ }
+
+ p = ((struct unit_addrs *)
+ backtrace_vector_grow (state, sizeof (struct unit_addrs),
+ error_callback, data, &vec->vec));
+ if (p == NULL)
+ return 0;
+
+ *p = addrs;
+ ++vec->count;
+ return 1;
+}
+
+/* Free a unit address vector. */
+
+static void
+free_unit_addrs_vector (struct backtrace_state *state,
+ struct unit_addrs_vector *vec,
+ backtrace_error_callback error_callback, void *data)
+{
+ struct unit_addrs *addrs;
+ size_t i;
+
+ addrs = (struct unit_addrs *) vec->vec.base;
+ for (i = 0; i < vec->count; ++i)
+ free_abbrevs (state, &addrs[i].u->abbrevs, error_callback, data);
+}
+
+/* Compare unit_addrs for qsort. When ranges are nested, make the
+ smallest one sort last. */
+
+static int
+unit_addrs_compare (const void *v1, const void *v2)
+{
+ const struct unit_addrs *a1 = (const struct unit_addrs *) v1;
+ const struct unit_addrs *a2 = (const struct unit_addrs *) v2;
+
+ if (a1->low < a2->low)
+ return -1;
+ if (a1->low > a2->low)
+ return 1;
+ if (a1->high < a2->high)
+ return 1;
+ if (a1->high > a2->high)
+ return -1;
+ if (a1->u->lineoff < a2->u->lineoff)
+ return -1;
+ if (a1->u->lineoff > a2->u->lineoff)
+ return 1;
+ return 0;
+}
+
+/* Compare a PC against a unit_addrs for bsearch. Note that if there
+ are multiple ranges containing PC, which one will be returned is
+ unpredictable. We compensate for that in dwarf_fileline. */
+
+static int
+unit_addrs_search (const void *vkey, const void *ventry)
+{
+ const uintptr_t *key = (const uintptr_t *) vkey;
+ const struct unit_addrs *entry = (const struct unit_addrs *) ventry;
+ uintptr_t pc;
+
+ pc = *key;
+ if (pc < entry->low)
+ return -1;
+ else if (pc >= entry->high)
+ return 1;
+ else
+ return 0;
+}
+
+/* Sort the line vector by PC. We want a stable sort here to maintain
+ the order of lines for the same PC values. Since the sequence is
+ being sorted in place, their addresses cannot be relied on to
+ maintain stability. That is the purpose of the index member. */
+
+static int
+line_compare (const void *v1, const void *v2)
+{
+ const struct line *ln1 = (const struct line *) v1;
+ const struct line *ln2 = (const struct line *) v2;
+
+ if (ln1->pc < ln2->pc)
+ return -1;
+ else if (ln1->pc > ln2->pc)
+ return 1;
+ else if (ln1->idx < ln2->idx)
+ return -1;
+ else if (ln1->idx > ln2->idx)
+ return 1;
+ else
+ return 0;
+}
+
+/* Find a PC in a line vector. We always allocate an extra entry at
+ the end of the lines vector, so that this routine can safely look
+ at the next entry. Note that when there are multiple mappings for
+ the same PC value, this will return the last one. */
+
+static int
+line_search (const void *vkey, const void *ventry)
+{
+ const uintptr_t *key = (const uintptr_t *) vkey;
+ const struct line *entry = (const struct line *) ventry;
+ uintptr_t pc;
+
+ pc = *key;
+ if (pc < entry->pc)
+ return -1;
+ else if (pc >= (entry + 1)->pc)
+ return 1;
+ else
+ return 0;
+}
+
+/* Sort the abbrevs by the abbrev code. This function is passed to
+ both qsort and bsearch. */
+
+static int
+abbrev_compare (const void *v1, const void *v2)
+{
+ const struct abbrev *a1 = (const struct abbrev *) v1;
+ const struct abbrev *a2 = (const struct abbrev *) v2;
+
+ if (a1->code < a2->code)
+ return -1;
+ else if (a1->code > a2->code)
+ return 1;
+ else
+ {
+ /* This really shouldn't happen. It means there are two
+ different abbrevs with the same code, and that means we don't
+ know which one lookup_abbrev should return. */
+ return 0;
+ }
+}
+
+/* Read the abbreviation table for a compilation unit. Returns 1 on
+ success, 0 on failure. */
+
+static int
+read_abbrevs (struct backtrace_state *state, uint64_t abbrev_offset,
+ const unsigned char *dwarf_abbrev, size_t dwarf_abbrev_size,
+ int is_bigendian, backtrace_error_callback error_callback,
+ void *data, struct abbrevs *abbrevs)
+{
+ struct dwarf_buf abbrev_buf;
+ struct dwarf_buf count_buf;
+ size_t num_abbrevs;
+
+ abbrevs->num_abbrevs = 0;
+ abbrevs->abbrevs = NULL;
+
+ if (abbrev_offset >= dwarf_abbrev_size)
+ {
+ error_callback (data, "abbrev offset out of range", 0);
+ return 0;
+ }
+
+ abbrev_buf.name = ".debug_abbrev";
+ abbrev_buf.start = dwarf_abbrev;
+ abbrev_buf.buf = dwarf_abbrev + abbrev_offset;
+ abbrev_buf.left = dwarf_abbrev_size - abbrev_offset;
+ abbrev_buf.is_bigendian = is_bigendian;
+ abbrev_buf.error_callback = error_callback;
+ abbrev_buf.data = data;
+ abbrev_buf.reported_underflow = 0;
+
+ /* Count the number of abbrevs in this list. */
+
+ count_buf = abbrev_buf;
+ num_abbrevs = 0;
+ while (read_uleb128 (&count_buf) != 0)
+ {
+ if (count_buf.reported_underflow)
+ return 0;
+ ++num_abbrevs;
+ // Skip tag.
+ read_uleb128 (&count_buf);
+ // Skip has_children.
+ read_byte (&count_buf);
+ // Skip attributes.
+ while (read_uleb128 (&count_buf) != 0)
+ read_uleb128 (&count_buf);
+ // Skip form of last attribute.
+ read_uleb128 (&count_buf);
+ }
+
+ if (count_buf.reported_underflow)
+ return 0;
+
+ if (num_abbrevs == 0)
+ return 1;
+
+ abbrevs->num_abbrevs = num_abbrevs;
+ abbrevs->abbrevs = ((struct abbrev *)
+ backtrace_alloc (state,
+ num_abbrevs * sizeof (struct abbrev),
+ error_callback, data));
+ if (abbrevs->abbrevs == NULL)
+ return 0;
+ memset (abbrevs->abbrevs, 0, num_abbrevs * sizeof (struct abbrev));
+
+ num_abbrevs = 0;
+ while (1)
+ {
+ uint64_t code;
+ struct abbrev a;
+ size_t num_attrs;
+ struct attr *attrs;
+
+ if (abbrev_buf.reported_underflow)
+ goto fail;
+
+ code = read_uleb128 (&abbrev_buf);
+ if (code == 0)
+ break;
+
+ a.code = code;
+ a.tag = (enum dwarf_tag) read_uleb128 (&abbrev_buf);
+ a.has_children = read_byte (&abbrev_buf);
+
+ count_buf = abbrev_buf;
+ num_attrs = 0;
+ while (read_uleb128 (&count_buf) != 0)
+ {
+ ++num_attrs;
+ read_uleb128 (&count_buf);
+ }
+
+ if (num_attrs == 0)
+ {
+ attrs = NULL;
+ read_uleb128 (&abbrev_buf);
+ read_uleb128 (&abbrev_buf);
+ }
+ else
+ {
+ attrs = ((struct attr *)
+ backtrace_alloc (state, num_attrs * sizeof *attrs,
+ error_callback, data));
+ if (attrs == NULL)
+ goto fail;
+ num_attrs = 0;
+ while (1)
+ {
+ uint64_t name;
+ uint64_t form;
+
+ name = read_uleb128 (&abbrev_buf);
+ form = read_uleb128 (&abbrev_buf);
+ if (name == 0)
+ break;
+ attrs[num_attrs].name = (enum dwarf_attribute) name;
+ attrs[num_attrs].form = (enum dwarf_form) form;
+ ++num_attrs;
+ }
+ }
+
+ a.num_attrs = num_attrs;
+ a.attrs = attrs;
+
+ abbrevs->abbrevs[num_abbrevs] = a;
+ ++num_abbrevs;
+ }
+
+ backtrace_qsort (abbrevs->abbrevs, abbrevs->num_abbrevs,
+ sizeof (struct abbrev), abbrev_compare);
+
+ return 1;
+
+ fail:
+ free_abbrevs (state, abbrevs, error_callback, data);
+ return 0;
+}
+
+/* Return the abbrev information for an abbrev code. */
+
+static const struct abbrev *
+lookup_abbrev (struct abbrevs *abbrevs, uint64_t code,
+ backtrace_error_callback error_callback, void *data)
+{
+ struct abbrev key;
+ void *p;
+
+ /* With GCC, where abbrevs are simply numbered in order, we should
+ be able to just look up the entry. */
+ if (code - 1 < abbrevs->num_abbrevs
+ && abbrevs->abbrevs[code - 1].code == code)
+ return &abbrevs->abbrevs[code - 1];
+
+ /* Otherwise we have to search. */
+ memset (&key, 0, sizeof key);
+ key.code = code;
+ p = bsearch (&key, abbrevs->abbrevs, abbrevs->num_abbrevs,
+ sizeof (struct abbrev), abbrev_compare);
+ if (p == NULL)
+ {
+ error_callback (data, "invalid abbreviation code", 0);
+ return NULL;
+ }
+ return (const struct abbrev *) p;
+}
+
+/* Add non-contiguous address ranges for a compilation unit. Returns
+ 1 on success, 0 on failure. */
+
+static int
+add_unit_ranges (struct backtrace_state *state, uintptr_t base_address,
+ struct unit *u, uint64_t ranges, uint64_t base,
+ int is_bigendian, const unsigned char *dwarf_ranges,
+ size_t dwarf_ranges_size,
+ backtrace_error_callback error_callback, void *data,
+ struct unit_addrs_vector *addrs)
+{
+ struct dwarf_buf ranges_buf;
+
+ if (ranges >= dwarf_ranges_size)
+ {
+ error_callback (data, "ranges offset out of range", 0);
+ return 0;
+ }
+
+ ranges_buf.name = ".debug_ranges";
+ ranges_buf.start = dwarf_ranges;
+ ranges_buf.buf = dwarf_ranges + ranges;
+ ranges_buf.left = dwarf_ranges_size - ranges;
+ ranges_buf.is_bigendian = is_bigendian;
+ ranges_buf.error_callback = error_callback;
+ ranges_buf.data = data;
+ ranges_buf.reported_underflow = 0;
+
+ while (1)
+ {
+ uint64_t low;
+ uint64_t high;
+
+ if (ranges_buf.reported_underflow)
+ return 0;
+
+ low = read_address (&ranges_buf, u->addrsize);
+ high = read_address (&ranges_buf, u->addrsize);
+
+ if (low == 0 && high == 0)
+ break;
+
+ if (is_highest_address (low, u->addrsize))
+ base = high;
+ else
+ {
+ struct unit_addrs a;
+
+ a.low = low + base;
+ a.high = high + base;
+ a.u = u;
+ if (!add_unit_addr (state, base_address, a, error_callback, data,
+ addrs))
+ return 0;
+ }
+ }
+
+ if (ranges_buf.reported_underflow)
+ return 0;
+
+ return 1;
+}
+
+/* Find the address range covered by a compilation unit, reading from
+ UNIT_BUF and adding values to U. Returns 1 if all data could be
+ read, 0 if there is some error. */
+
+static int
+find_address_ranges (struct backtrace_state *state, uintptr_t base_address,
+ struct dwarf_buf *unit_buf,
+ const unsigned char *dwarf_str, size_t dwarf_str_size,
+ const unsigned char *dwarf_ranges,
+ size_t dwarf_ranges_size,
+ int is_bigendian, backtrace_error_callback error_callback,
+ void *data, struct unit *u,
+ struct unit_addrs_vector *addrs)
+{
+ while (unit_buf->left > 0)
+ {
+ uint64_t code;
+ const struct abbrev *abbrev;
+ uint64_t lowpc;
+ int have_lowpc;
+ uint64_t highpc;
+ int have_highpc;
+ int highpc_is_relative;
+ uint64_t ranges;
+ int have_ranges;
+ size_t i;
+
+ code = read_uleb128 (unit_buf);
+ if (code == 0)
+ return 1;
+
+ abbrev = lookup_abbrev (&u->abbrevs, code, error_callback, data);
+ if (abbrev == NULL)
+ return 0;
+
+ lowpc = 0;
+ have_lowpc = 0;
+ highpc = 0;
+ have_highpc = 0;
+ highpc_is_relative = 0;
+ ranges = 0;
+ have_ranges = 0;
+ for (i = 0; i < abbrev->num_attrs; ++i)
+ {
+ struct attr_val val;
+
+ if (!read_attribute (abbrev->attrs[i].form, unit_buf,
+ u->is_dwarf64, u->version, u->addrsize,
+ dwarf_str, dwarf_str_size, &val))
+ return 0;
+
+ switch (abbrev->attrs[i].name)
+ {
+ case DW_AT_low_pc:
+ if (val.encoding == ATTR_VAL_ADDRESS)
+ {
+ lowpc = val.u.uint;
+ have_lowpc = 1;
+ }
+ break;
+
+ case DW_AT_high_pc:
+ if (val.encoding == ATTR_VAL_ADDRESS)
+ {
+ highpc = val.u.uint;
+ have_highpc = 1;
+ }
+ else if (val.encoding == ATTR_VAL_UINT)
+ {
+ highpc = val.u.uint;
+ have_highpc = 1;
+ highpc_is_relative = 1;
+ }
+ break;
+
+ case DW_AT_ranges:
+ if (val.encoding == ATTR_VAL_UINT
+ || val.encoding == ATTR_VAL_REF_SECTION)
+ {
+ ranges = val.u.uint;
+ have_ranges = 1;
+ }
+ break;
+
+ case DW_AT_stmt_list:
+ if (abbrev->tag == DW_TAG_compile_unit
+ && (val.encoding == ATTR_VAL_UINT
+ || val.encoding == ATTR_VAL_REF_SECTION))
+ u->lineoff = val.u.uint;
+ break;
+
+ case DW_AT_name:
+ if (abbrev->tag == DW_TAG_compile_unit
+ && val.encoding == ATTR_VAL_STRING)
+ u->filename = val.u.string;
+ break;
+
+ case DW_AT_comp_dir:
+ if (abbrev->tag == DW_TAG_compile_unit
+ && val.encoding == ATTR_VAL_STRING)
+ u->comp_dir = val.u.string;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ if (abbrev->tag == DW_TAG_compile_unit
+ || abbrev->tag == DW_TAG_subprogram)
+ {
+ if (have_ranges)
+ {
+ if (!add_unit_ranges (state, base_address, u, ranges, lowpc,
+ is_bigendian, dwarf_ranges,
+ dwarf_ranges_size, error_callback,
+ data, addrs))
+ return 0;
+ }
+ else if (have_lowpc && have_highpc)
+ {
+ struct unit_addrs a;
+
+ if (highpc_is_relative)
+ highpc += lowpc;
+ a.low = lowpc;
+ a.high = highpc;
+ a.u = u;
+
+ if (!add_unit_addr (state, base_address, a, error_callback, data,
+ addrs))
+ return 0;
+ }
+
+ /* If we found the PC range in the DW_TAG_compile_unit, we
+ can stop now. */
+ if (abbrev->tag == DW_TAG_compile_unit
+ && (have_ranges || (have_lowpc && have_highpc)))
+ return 1;
+ }
+
+ if (abbrev->has_children)
+ {
+ if (!find_address_ranges (state, base_address, unit_buf,
+ dwarf_str, dwarf_str_size,
+ dwarf_ranges, dwarf_ranges_size,
+ is_bigendian, error_callback, data,
+ u, addrs))
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/* Build a mapping from address ranges to the compilation units where
+ the line number information for that range can be found. Returns 1
+ on success, 0 on failure. */
+
+static int
+build_address_map (struct backtrace_state *state, uintptr_t base_address,
+ const unsigned char *dwarf_info, size_t dwarf_info_size,
+ const unsigned char *dwarf_abbrev, size_t dwarf_abbrev_size,
+ const unsigned char *dwarf_ranges, size_t dwarf_ranges_size,
+ const unsigned char *dwarf_str, size_t dwarf_str_size,
+ int is_bigendian, backtrace_error_callback error_callback,
+ void *data, struct unit_addrs_vector *addrs)
+{
+ struct dwarf_buf info;
+ struct abbrevs abbrevs;
+
+ memset (&addrs->vec, 0, sizeof addrs->vec);
+ addrs->count = 0;
+
+ /* Read through the .debug_info section. FIXME: Should we use the
+ .debug_aranges section? gdb and addr2line don't use it, but I'm
+ not sure why. */
+
+ info.name = ".debug_info";
+ info.start = dwarf_info;
+ info.buf = dwarf_info;
+ info.left = dwarf_info_size;
+ info.is_bigendian = is_bigendian;
+ info.error_callback = error_callback;
+ info.data = data;
+ info.reported_underflow = 0;
+
+ memset (&abbrevs, 0, sizeof abbrevs);
+ while (info.left > 0)
+ {
+ const unsigned char *unit_data_start;
+ uint64_t len;
+ int is_dwarf64;
+ struct dwarf_buf unit_buf;
+ int version;
+ uint64_t abbrev_offset;
+ int addrsize;
+ struct unit *u;
+
+ if (info.reported_underflow)
+ goto fail;
+
+ unit_data_start = info.buf;
+
+ is_dwarf64 = 0;
+ len = read_uint32 (&info);
+ if (len == 0xffffffff)
+ {
+ len = read_uint64 (&info);
+ is_dwarf64 = 1;
+ }
+
+ unit_buf = info;
+ unit_buf.left = len;
+
+ if (!advance (&info, len))
+ goto fail;
+
+ version = read_uint16 (&unit_buf);
+ if (version < 2 || version > 4)
+ {
+ dwarf_buf_error (&unit_buf, "unrecognized DWARF version");
+ goto fail;
+ }
+
+ abbrev_offset = read_offset (&unit_buf, is_dwarf64);
+ if (!read_abbrevs (state, abbrev_offset, dwarf_abbrev, dwarf_abbrev_size,
+ is_bigendian, error_callback, data, &abbrevs))
+ goto fail;
+
+ addrsize = read_byte (&unit_buf);
+
+ u = ((struct unit *)
+ backtrace_alloc (state, sizeof *u, error_callback, data));
+ if (u == NULL)
+ goto fail;
+ u->unit_data = unit_buf.buf;
+ u->unit_data_len = unit_buf.left;
+ u->unit_data_offset = unit_buf.buf - unit_data_start;
+ u->version = version;
+ u->is_dwarf64 = is_dwarf64;
+ u->addrsize = addrsize;
+ u->filename = NULL;
+ u->comp_dir = NULL;
+ u->abs_filename = NULL;
+ u->lineoff = 0;
+ u->abbrevs = abbrevs;
+ memset (&abbrevs, 0, sizeof abbrevs);
+
+ /* The actual line number mappings will be read as needed. */
+ u->lines = NULL;
+ u->lines_count = 0;
+ u->function_addrs = NULL;
+ u->function_addrs_count = 0;
+
+ if (!find_address_ranges (state, base_address, &unit_buf,
+ dwarf_str, dwarf_str_size,
+ dwarf_ranges, dwarf_ranges_size,
+ is_bigendian, error_callback, data,
+ u, addrs))
+ {
+ free_abbrevs (state, &u->abbrevs, error_callback, data);
+ backtrace_free (state, u, sizeof *u, error_callback, data);
+ goto fail;
+ }
+
+ if (unit_buf.reported_underflow)
+ {
+ free_abbrevs (state, &u->abbrevs, error_callback, data);
+ backtrace_free (state, u, sizeof *u, error_callback, data);
+ goto fail;
+ }
+ }
+ if (info.reported_underflow)
+ goto fail;
+
+ return 1;
+
+ fail:
+ free_abbrevs (state, &abbrevs, error_callback, data);
+ free_unit_addrs_vector (state, addrs, error_callback, data);
+ return 0;
+}
+
+/* Add a new mapping to the vector of line mappings that we are
+ building. Returns 1 on success, 0 on failure. */
+
+static int
+add_line (struct backtrace_state *state, struct dwarf_data *ddata,
+ uintptr_t pc, const char *filename, int lineno,
+ backtrace_error_callback error_callback, void *data,
+ struct line_vector *vec)
+{
+ struct line *ln;
+
+ /* If we are adding the same mapping, ignore it. This can happen
+ when using discriminators. */
+ if (vec->count > 0)
+ {
+ ln = (struct line *) vec->vec.base + (vec->count - 1);
+ if (pc == ln->pc && filename == ln->filename && lineno == ln->lineno)
+ return 1;
+ }
+
+ ln = ((struct line *)
+ backtrace_vector_grow (state, sizeof (struct line), error_callback,
+ data, &vec->vec));
+ if (ln == NULL)
+ return 0;
+
+ /* Add in the base address here, so that we can look up the PC
+ directly. */
+ ln->pc = pc + ddata->base_address;
+
+ ln->filename = filename;
+ ln->lineno = lineno;
+ ln->idx = (int)vec->count;
+
+ ++vec->count;
+
+ return 1;
+}
+
+/* Free the line header information. */
+
+static void
+free_line_header (struct backtrace_state *state, struct line_header *hdr,
+ backtrace_error_callback error_callback, void *data)
+{
+ if (hdr->dirs_count != 0)
+ backtrace_free (state, hdr->dirs, hdr->dirs_count * sizeof (const char *),
+ error_callback, data);
+ backtrace_free (state, hdr->filenames,
+ hdr->filenames_count * sizeof (char *),
+ error_callback, data);
+}
+
+/* Read the line header. Return 1 on success, 0 on failure. */
+
+static int
+read_line_header (struct backtrace_state *state, struct unit *u,
+ int is_dwarf64, struct dwarf_buf *line_buf,
+ struct line_header *hdr)
+{
+ uint64_t hdrlen;
+ struct dwarf_buf hdr_buf;
+ const unsigned char *p;
+ const unsigned char *pend;
+ size_t i;
+
+ hdr->version = read_uint16 (line_buf);
+ if (hdr->version < 2 || hdr->version > 4)
+ {
+ dwarf_buf_error (line_buf, "unsupported line number version");
+ return 0;
+ }
+
+ hdrlen = read_offset (line_buf, is_dwarf64);
+
+ hdr_buf = *line_buf;
+ hdr_buf.left = hdrlen;
+
+ if (!advance (line_buf, hdrlen))
+ return 0;
+
+ hdr->min_insn_len = read_byte (&hdr_buf);
+ if (hdr->version < 4)
+ hdr->max_ops_per_insn = 1;
+ else
+ hdr->max_ops_per_insn = read_byte (&hdr_buf);
+
+ /* We don't care about default_is_stmt. */
+ read_byte (&hdr_buf);
+
+ hdr->line_base = read_sbyte (&hdr_buf);
+ hdr->line_range = read_byte (&hdr_buf);
+
+ hdr->opcode_base = read_byte (&hdr_buf);
+ hdr->opcode_lengths = hdr_buf.buf;
+ if (!advance (&hdr_buf, hdr->opcode_base - 1))
+ return 0;
+
+ /* Count the number of directory entries. */
+ hdr->dirs_count = 0;
+ p = hdr_buf.buf;
+ pend = p + hdr_buf.left;
+ while (p < pend && *p != '\0')
+ {
+ p += strnlen((const char *) p, pend - p) + 1;
+ ++hdr->dirs_count;
+ }
+
+ hdr->dirs = NULL;
+ if (hdr->dirs_count != 0)
+ {
+ hdr->dirs = ((const char **)
+ backtrace_alloc (state,
+ hdr->dirs_count * sizeof (const char *),
+ line_buf->error_callback, line_buf->data));
+ if (hdr->dirs == NULL)
+ return 0;
+ }
+
+ i = 0;
+ while (*hdr_buf.buf != '\0')
+ {
+ if (hdr_buf.reported_underflow)
+ return 0;
+
+ hdr->dirs[i] = (const char *) hdr_buf.buf;
+ ++i;
+ if (!advance (&hdr_buf,
+ strnlen ((const char *) hdr_buf.buf, hdr_buf.left) + 1))
+ return 0;
+ }
+ if (!advance (&hdr_buf, 1))
+ return 0;
+
+ /* Count the number of file entries. */
+ hdr->filenames_count = 0;
+ p = hdr_buf.buf;
+ pend = p + hdr_buf.left;
+ while (p < pend && *p != '\0')
+ {
+ p += strnlen ((const char *) p, pend - p) + 1;
+ p += leb128_len (p);
+ p += leb128_len (p);
+ p += leb128_len (p);
+ ++hdr->filenames_count;
+ }
+
+ hdr->filenames = ((const char **)
+ backtrace_alloc (state,
+ hdr->filenames_count * sizeof (char *),
+ line_buf->error_callback,
+ line_buf->data));
+ if (hdr->filenames == NULL)
+ return 0;
+ i = 0;
+ while (*hdr_buf.buf != '\0')
+ {
+ const char *filename;
+ uint64_t dir_index;
+
+ if (hdr_buf.reported_underflow)
+ return 0;
+
+ filename = (const char *) hdr_buf.buf;
+ if (!advance (&hdr_buf,
+ strnlen ((const char *) hdr_buf.buf, hdr_buf.left) + 1))
+ return 0;
+ dir_index = read_uleb128 (&hdr_buf);
+ if (IS_ABSOLUTE_PATH (filename)
+ || (dir_index == 0 && u->comp_dir == NULL))
+ hdr->filenames[i] = filename;
+ else
+ {
+ const char *dir;
+ size_t dir_len;
+ size_t filename_len;
+ char *s;
+
+ if (dir_index == 0)
+ dir = u->comp_dir;
+ else if (dir_index - 1 < hdr->dirs_count)
+ dir = hdr->dirs[dir_index - 1];
+ else
+ {
+ dwarf_buf_error (line_buf,
+ ("invalid directory index in "
+ "line number program header"));
+ return 0;
+ }
+ dir_len = strlen (dir);
+ filename_len = strlen (filename);
+ s = ((char *)
+ backtrace_alloc (state, dir_len + filename_len + 2,
+ line_buf->error_callback, line_buf->data));
+ if (s == NULL)
+ return 0;
+ memcpy (s, dir, dir_len);
+ /* FIXME: If we are on a DOS-based file system, and the
+ directory or the file name use backslashes, then we
+ should use a backslash here. */
+ s[dir_len] = '/';
+ memcpy (s + dir_len + 1, filename, filename_len + 1);
+ hdr->filenames[i] = s;
+ }
+
+ /* Ignore the modification time and size. */
+ read_uleb128 (&hdr_buf);
+ read_uleb128 (&hdr_buf);
+
+ ++i;
+ }
+
+ if (hdr_buf.reported_underflow)
+ return 0;
+
+ return 1;
+}
+
+/* Read the line program, adding line mappings to VEC. Return 1 on
+ success, 0 on failure. */
+
+static int
+read_line_program (struct backtrace_state *state, struct dwarf_data *ddata,
+ struct unit *u, const struct line_header *hdr,
+ struct dwarf_buf *line_buf, struct line_vector *vec)
+{
+ uint64_t address;
+ unsigned int op_index;
+ const char *reset_filename;
+ const char *filename;
+ int lineno;
+
+ address = 0;
+ op_index = 0;
+ if (hdr->filenames_count > 0)
+ reset_filename = hdr->filenames[0];
+ else
+ reset_filename = "";
+ filename = reset_filename;
+ lineno = 1;
+ while (line_buf->left > 0)
+ {
+ unsigned int op;
+
+ op = read_byte (line_buf);
+ if (op >= hdr->opcode_base)
+ {
+ unsigned int advance;
+
+ /* Special opcode. */
+ op -= hdr->opcode_base;
+ advance = op / hdr->line_range;
+ address += (hdr->min_insn_len * (op_index + advance)
+ / hdr->max_ops_per_insn);
+ op_index = (op_index + advance) % hdr->max_ops_per_insn;
+ lineno += hdr->line_base + (int) (op % hdr->line_range);
+ add_line (state, ddata, address, filename, lineno,
+ line_buf->error_callback, line_buf->data, vec);
+ }
+ else if (op == DW_LNS_extended_op)
+ {
+ uint64_t len;
+
+ len = read_uleb128 (line_buf);
+ op = read_byte (line_buf);
+ switch (op)
+ {
+ case DW_LNE_end_sequence:
+ /* FIXME: Should we mark the high PC here? It seems
+ that we already have that information from the
+ compilation unit. */
+ address = 0;
+ op_index = 0;
+ filename = reset_filename;
+ lineno = 1;
+ break;
+ case DW_LNE_set_address:
+ address = read_address (line_buf, u->addrsize);
+ break;
+ case DW_LNE_define_file:
+ {
+ const char *f;
+ unsigned int dir_index;
+
+ f = (const char *) line_buf->buf;
+ if (!advance (line_buf, strnlen (f, line_buf->left) + 1))
+ return 0;
+ dir_index = (unsigned int)read_uleb128 (line_buf);
+ /* Ignore that time and length. */
+ read_uleb128 (line_buf);
+ read_uleb128 (line_buf);
+ if (IS_ABSOLUTE_PATH (f))
+ filename = f;
+ else
+ {
+ const char *dir;
+ size_t dir_len;
+ size_t f_len;
+ char *p;
+
+ if (dir_index == 0)
+ dir = u->comp_dir;
+ else if (dir_index - 1 < hdr->dirs_count)
+ dir = hdr->dirs[dir_index - 1];
+ else
+ {
+ dwarf_buf_error (line_buf,
+ ("invalid directory index "
+ "in line number program"));
+ return 0;
+ }
+ dir_len = strlen (dir);
+ f_len = strlen (f);
+ p = ((char *)
+ backtrace_alloc (state, dir_len + f_len + 2,
+ line_buf->error_callback,
+ line_buf->data));
+ if (p == NULL)
+ return 0;
+ memcpy (p, dir, dir_len);
+ /* FIXME: If we are on a DOS-based file system,
+ and the directory or the file name use
+ backslashes, then we should use a backslash
+ here. */
+ p[dir_len] = '/';
+ memcpy (p + dir_len + 1, f, f_len + 1);
+ filename = p;
+ }
+ }
+ break;
+ case DW_LNE_set_discriminator:
+ /* We don't care about discriminators. */
+ read_uleb128 (line_buf);
+ break;
+ default:
+ if (!advance (line_buf, len - 1))
+ return 0;
+ break;
+ }
+ }
+ else
+ {
+ switch (op)
+ {
+ case DW_LNS_copy:
+ add_line (state, ddata, address, filename, lineno,
+ line_buf->error_callback, line_buf->data, vec);
+ break;
+ case DW_LNS_advance_pc:
+ {
+ uint64_t advance;
+
+ advance = read_uleb128 (line_buf);
+ address += (hdr->min_insn_len * (op_index + advance)
+ / hdr->max_ops_per_insn);
+ op_index = (op_index + advance) % hdr->max_ops_per_insn;
+ }
+ break;
+ case DW_LNS_advance_line:
+ lineno += (int) read_sleb128 (line_buf);
+ break;
+ case DW_LNS_set_file:
+ {
+ uint64_t fileno;
+
+ fileno = read_uleb128 (line_buf);
+ if (fileno == 0)
+ filename = "";
+ else
+ {
+ if (fileno - 1 >= hdr->filenames_count)
+ {
+ dwarf_buf_error (line_buf,
+ ("invalid file number in "
+ "line number program"));
+ return 0;
+ }
+ filename = hdr->filenames[fileno - 1];
+ }
+ }
+ break;
+ case DW_LNS_set_column:
+ read_uleb128 (line_buf);
+ break;
+ case DW_LNS_negate_stmt:
+ break;
+ case DW_LNS_set_basic_block:
+ break;
+ case DW_LNS_const_add_pc:
+ {
+ unsigned int advance;
+
+ op = 255 - hdr->opcode_base;
+ advance = op / hdr->line_range;
+ address += (hdr->min_insn_len * (op_index + advance)
+ / hdr->max_ops_per_insn);
+ op_index = (op_index + advance) % hdr->max_ops_per_insn;
+ }
+ break;
+ case DW_LNS_fixed_advance_pc:
+ address += read_uint16 (line_buf);
+ op_index = 0;
+ break;
+ case DW_LNS_set_prologue_end:
+ break;
+ case DW_LNS_set_epilogue_begin:
+ break;
+ case DW_LNS_set_isa:
+ read_uleb128 (line_buf);
+ break;
+ default:
+ {
+ unsigned int i;
+
+ for (i = hdr->opcode_lengths[op - 1]; i > 0; --i)
+ read_uleb128 (line_buf);
+ }
+ break;
+ }
+ }
+ }
+
+ return 1;
+}
+
+/* Read the line number information for a compilation unit. Returns 1
+ on success, 0 on failure. */
+
+static int
+read_line_info (struct backtrace_state *state, struct dwarf_data *ddata,
+ backtrace_error_callback error_callback, void *data,
+ struct unit *u, struct line_header *hdr, struct line **lines,
+ size_t *lines_count)
+{
+ struct line_vector vec;
+ struct dwarf_buf line_buf;
+ uint64_t len;
+ int is_dwarf64;
+ struct line *ln;
+
+ memset (&vec.vec, 0, sizeof vec.vec);
+ vec.count = 0;
+
+ memset (hdr, 0, sizeof *hdr);
+
+ if (u->lineoff != (off_t) (size_t) u->lineoff
+ || (size_t) u->lineoff >= ddata->dwarf_line_size)
+ {
+ error_callback (data, "unit line offset out of range", 0);
+ goto fail;
+ }
+
+ line_buf.name = ".debug_line";
+ line_buf.start = ddata->dwarf_line;
+ line_buf.buf = ddata->dwarf_line + u->lineoff;
+ line_buf.left = ddata->dwarf_line_size - u->lineoff;
+ line_buf.is_bigendian = ddata->is_bigendian;
+ line_buf.error_callback = error_callback;
+ line_buf.data = data;
+ line_buf.reported_underflow = 0;
+
+ is_dwarf64 = 0;
+ len = read_uint32 (&line_buf);
+ if (len == 0xffffffff)
+ {
+ len = read_uint64 (&line_buf);
+ is_dwarf64 = 1;
+ }
+ line_buf.left = len;
+
+ if (!read_line_header (state, u, is_dwarf64, &line_buf, hdr))
+ goto fail;
+
+ if (!read_line_program (state, ddata, u, hdr, &line_buf, &vec))
+ goto fail;
+
+ if (line_buf.reported_underflow)
+ goto fail;
+
+ if (vec.count == 0)
+ {
+ /* This is not a failure in the sense of a generating an error,
+ but it is a failure in that sense that we have no useful
+ information. */
+ goto fail;
+ }
+
+ /* Allocate one extra entry at the end. */
+ ln = ((struct line *)
+ backtrace_vector_grow (state, sizeof (struct line), error_callback,
+ data, &vec.vec));
+ if (ln == NULL)
+ goto fail;
+ ln->pc = (uintptr_t) -1;
+ ln->filename = NULL;
+ ln->lineno = 0;
+ ln->idx = 0;
+
+ if (!backtrace_vector_release (state, &vec.vec, error_callback, data))
+ goto fail;
+
+ ln = (struct line *) vec.vec.base;
+ backtrace_qsort (ln, vec.count, sizeof (struct line), line_compare);
+
+ *lines = ln;
+ *lines_count = vec.count;
+
+ return 1;
+
+ fail:
+ vec.vec.alc += vec.vec.size;
+ vec.vec.size = 0;
+ backtrace_vector_release (state, &vec.vec, error_callback, data);
+ free_line_header (state, hdr, error_callback, data);
+ *lines = (struct line *) (uintptr_t) -1;
+ *lines_count = 0;
+ return 0;
+}
+
+/* Read the name of a function from a DIE referenced by a
+ DW_AT_abstract_origin or DW_AT_specification tag. OFFSET is within
+ the same compilation unit. */
+
+static const char *
+read_referenced_name (struct dwarf_data *ddata, struct unit *u,
+ uint64_t offset, backtrace_error_callback error_callback,
+ void *data)
+{
+ struct dwarf_buf unit_buf;
+ uint64_t code;
+ const struct abbrev *abbrev;
+ const char *ret;
+ size_t i;
+
+ /* OFFSET is from the start of the data for this compilation unit.
+ U->unit_data is the data, but it starts U->unit_data_offset bytes
+ from the beginning. */
+
+ if (offset < u->unit_data_offset
+ || offset - u->unit_data_offset >= u->unit_data_len)
+ {
+ error_callback (data,
+ "abstract origin or specification out of range",
+ 0);
+ return NULL;
+ }
+
+ offset -= u->unit_data_offset;
+
+ unit_buf.name = ".debug_info";
+ unit_buf.start = ddata->dwarf_info;
+ unit_buf.buf = u->unit_data + offset;
+ unit_buf.left = u->unit_data_len - offset;
+ unit_buf.is_bigendian = ddata->is_bigendian;
+ unit_buf.error_callback = error_callback;
+ unit_buf.data = data;
+ unit_buf.reported_underflow = 0;
+
+ code = read_uleb128 (&unit_buf);
+ if (code == 0)
+ {
+ dwarf_buf_error (&unit_buf, "invalid abstract origin or specification");
+ return NULL;
+ }
+
+ abbrev = lookup_abbrev (&u->abbrevs, code, error_callback, data);
+ if (abbrev == NULL)
+ return NULL;
+
+ ret = NULL;
+ for (i = 0; i < abbrev->num_attrs; ++i)
+ {
+ struct attr_val val;
+
+ if (!read_attribute (abbrev->attrs[i].form, &unit_buf,
+ u->is_dwarf64, u->version, u->addrsize,
+ ddata->dwarf_str, ddata->dwarf_str_size,
+ &val))
+ return NULL;
+
+ switch (abbrev->attrs[i].name)
+ {
+ case DW_AT_name:
+ /* We prefer the linkage name if get one. */
+ if (val.encoding == ATTR_VAL_STRING)
+ ret = val.u.string;
+ break;
+
+ case DW_AT_linkage_name:
+ case DW_AT_MIPS_linkage_name:
+ if (val.encoding == ATTR_VAL_STRING)
+ return val.u.string;
+ break;
+
+ case DW_AT_specification:
+ if (abbrev->attrs[i].form == DW_FORM_ref_addr
+ || abbrev->attrs[i].form == DW_FORM_ref_sig8)
+ {
+ /* This refers to a specification defined in some other
+ compilation unit. We can handle this case if we
+ must, but it's harder. */
+ break;
+ }
+ if (val.encoding == ATTR_VAL_UINT
+ || val.encoding == ATTR_VAL_REF_UNIT)
+ {
+ const char *name;
+
+ name = read_referenced_name (ddata, u, val.u.uint,
+ error_callback, data);
+ if (name != NULL)
+ ret = name;
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/* Add a single range to U that maps to function. Returns 1 on
+ success, 0 on error. */
+
+static int
+add_function_range (struct backtrace_state *state, struct dwarf_data *ddata,
+ struct function *function, uint64_t lowpc, uint64_t highpc,
+ backtrace_error_callback error_callback,
+ void *data, struct function_vector *vec)
+{
+ struct function_addrs *p;
+
+ /* Add in the base address here, so that we can look up the PC
+ directly. */
+ lowpc += ddata->base_address;
+ highpc += ddata->base_address;
+
+ if (vec->count > 0)
+ {
+ p = (struct function_addrs *) vec->vec.base + vec->count - 1;
+ if ((lowpc == p->high || lowpc == p->high + 1)
+ && function == p->function)
+ {
+ if (highpc > p->high)
+ p->high = highpc;
+ return 1;
+ }
+ }
+
+ p = ((struct function_addrs *)
+ backtrace_vector_grow (state, sizeof (struct function_addrs),
+ error_callback, data, &vec->vec));
+ if (p == NULL)
+ return 0;
+
+ p->low = lowpc;
+ p->high = highpc;
+ p->function = function;
+ ++vec->count;
+ return 1;
+}
+
+/* Add PC ranges to U that map to FUNCTION. Returns 1 on success, 0
+ on error. */
+
+static int
+add_function_ranges (struct backtrace_state *state, struct dwarf_data *ddata,
+ struct unit *u, struct function *function,
+ uint64_t ranges, uint64_t base,
+ backtrace_error_callback error_callback, void *data,
+ struct function_vector *vec)
+{
+ struct dwarf_buf ranges_buf;
+
+ if (ranges >= ddata->dwarf_ranges_size)
+ {
+ error_callback (data, "function ranges offset out of range", 0);
+ return 0;
+ }
+
+ ranges_buf.name = ".debug_ranges";
+ ranges_buf.start = ddata->dwarf_ranges;
+ ranges_buf.buf = ddata->dwarf_ranges + ranges;
+ ranges_buf.left = ddata->dwarf_ranges_size - ranges;
+ ranges_buf.is_bigendian = ddata->is_bigendian;
+ ranges_buf.error_callback = error_callback;
+ ranges_buf.data = data;
+ ranges_buf.reported_underflow = 0;
+
+ while (1)
+ {
+ uint64_t low;
+ uint64_t high;
+
+ if (ranges_buf.reported_underflow)
+ return 0;
+
+ low = read_address (&ranges_buf, u->addrsize);
+ high = read_address (&ranges_buf, u->addrsize);
+
+ if (low == 0 && high == 0)
+ break;
+
+ if (is_highest_address (low, u->addrsize))
+ base = high;
+ else
+ {
+ if (!add_function_range (state, ddata, function, low + base,
+ high + base, error_callback, data, vec))
+ return 0;
+ }
+ }
+
+ if (ranges_buf.reported_underflow)
+ return 0;
+
+ return 1;
+}
+
+/* Read one entry plus all its children. Add function addresses to
+ VEC. Returns 1 on success, 0 on error. */
+
+static int
+read_function_entry (struct backtrace_state *state, struct dwarf_data *ddata,
+ struct unit *u, uint64_t base, struct dwarf_buf *unit_buf,
+ const struct line_header *lhdr,
+ backtrace_error_callback error_callback, void *data,
+ struct function_vector *vec_function,
+ struct function_vector *vec_inlined)
+{
+ while (unit_buf->left > 0)
+ {
+ uint64_t code;
+ const struct abbrev *abbrev;
+ int is_function;
+ struct function *function;
+ struct function_vector *vec;
+ size_t i;
+ uint64_t lowpc;
+ int have_lowpc;
+ uint64_t highpc;
+ int have_highpc;
+ int highpc_is_relative;
+ uint64_t ranges;
+ int have_ranges;
+
+ code = read_uleb128 (unit_buf);
+ if (code == 0)
+ return 1;
+
+ abbrev = lookup_abbrev (&u->abbrevs, code, error_callback, data);
+ if (abbrev == NULL)
+ return 0;
+
+ is_function = (abbrev->tag == DW_TAG_subprogram
+ || abbrev->tag == DW_TAG_entry_point
+ || abbrev->tag == DW_TAG_inlined_subroutine);
+
+ if (abbrev->tag == DW_TAG_inlined_subroutine)
+ vec = vec_inlined;
+ else
+ vec = vec_function;
+
+ function = NULL;
+ if (is_function)
+ {
+ function = ((struct function *)
+ backtrace_alloc (state, sizeof *function,
+ error_callback, data));
+ if (function == NULL)
+ return 0;
+ memset (function, 0, sizeof *function);
+ }
+
+ lowpc = 0;
+ have_lowpc = 0;
+ highpc = 0;
+ have_highpc = 0;
+ highpc_is_relative = 0;
+ ranges = 0;
+ have_ranges = 0;
+ for (i = 0; i < abbrev->num_attrs; ++i)
+ {
+ struct attr_val val;
+
+ if (!read_attribute (abbrev->attrs[i].form, unit_buf,
+ u->is_dwarf64, u->version, u->addrsize,
+ ddata->dwarf_str, ddata->dwarf_str_size,
+ &val))
+ return 0;
+
+ /* The compile unit sets the base address for any address
+ ranges in the function entries. */
+ if (abbrev->tag == DW_TAG_compile_unit
+ && abbrev->attrs[i].name == DW_AT_low_pc
+ && val.encoding == ATTR_VAL_ADDRESS)
+ base = val.u.uint;
+
+ if (is_function)
+ {
+ switch (abbrev->attrs[i].name)
+ {
+ case DW_AT_call_file:
+ if (val.encoding == ATTR_VAL_UINT)
+ {
+ if (val.u.uint == 0)
+ function->caller_filename = "";
+ else
+ {
+ if (val.u.uint - 1 >= lhdr->filenames_count)
+ {
+ dwarf_buf_error (unit_buf,
+ ("invalid file number in "
+ "DW_AT_call_file attribute"));
+ return 0;
+ }
+ function->caller_filename =
+ lhdr->filenames[val.u.uint - 1];
+ }
+ }
+ break;
+
+ case DW_AT_call_line:
+ if (val.encoding == ATTR_VAL_UINT)
+ function->caller_lineno = (int)val.u.uint;
+ break;
+
+ case DW_AT_abstract_origin:
+ case DW_AT_specification:
+ if (abbrev->attrs[i].form == DW_FORM_ref_addr
+ || abbrev->attrs[i].form == DW_FORM_ref_sig8)
+ {
+ /* This refers to an abstract origin defined in
+ some other compilation unit. We can handle
+ this case if we must, but it's harder. */
+ break;
+ }
+ if (val.encoding == ATTR_VAL_UINT
+ || val.encoding == ATTR_VAL_REF_UNIT)
+ {
+ const char *name;
+
+ name = read_referenced_name (ddata, u, val.u.uint,
+ error_callback, data);
+ if (name != NULL)
+ function->name = name;
+ }
+ break;
+
+ case DW_AT_name:
+ if (val.encoding == ATTR_VAL_STRING)
+ {
+ /* Don't override a name we found in some other
+ way, as it will normally be more
+ useful--e.g., this name is normally not
+ mangled. */
+ if (function->name == NULL)
+ function->name = val.u.string;
+ }
+ break;
+
+ case DW_AT_linkage_name:
+ case DW_AT_MIPS_linkage_name:
+ if (val.encoding == ATTR_VAL_STRING)
+ function->name = val.u.string;
+ break;
+
+ case DW_AT_low_pc:
+ if (val.encoding == ATTR_VAL_ADDRESS)
+ {
+ lowpc = val.u.uint;
+ have_lowpc = 1;
+ }
+ break;
+
+ case DW_AT_high_pc:
+ if (val.encoding == ATTR_VAL_ADDRESS)
+ {
+ highpc = val.u.uint;
+ have_highpc = 1;
+ }
+ else if (val.encoding == ATTR_VAL_UINT)
+ {
+ highpc = val.u.uint;
+ have_highpc = 1;
+ highpc_is_relative = 1;
+ }
+ break;
+
+ case DW_AT_ranges:
+ if (val.encoding == ATTR_VAL_UINT
+ || val.encoding == ATTR_VAL_REF_SECTION)
+ {
+ ranges = val.u.uint;
+ have_ranges = 1;
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+ /* If we couldn't find a name for the function, we have no use
+ for it. */
+ if (is_function && function->name == NULL)
+ {
+ backtrace_free (state, function, sizeof *function,
+ error_callback, data);
+ is_function = 0;
+ }
+
+ if (is_function)
+ {
+ if (have_ranges)
+ {
+ if (!add_function_ranges (state, ddata, u, function, ranges,
+ base, error_callback, data, vec))
+ return 0;
+ }
+ else if (have_lowpc && have_highpc)
+ {
+ if (highpc_is_relative)
+ highpc += lowpc;
+ if (!add_function_range (state, ddata, function, lowpc, highpc,
+ error_callback, data, vec))
+ return 0;
+ }
+ else
+ {
+ backtrace_free (state, function, sizeof *function,
+ error_callback, data);
+ is_function = 0;
+ }
+ }
+
+ if (abbrev->has_children)
+ {
+ if (!is_function)
+ {
+ if (!read_function_entry (state, ddata, u, base, unit_buf, lhdr,
+ error_callback, data, vec_function,
+ vec_inlined))
+ return 0;
+ }
+ else
+ {
+ struct function_vector fvec;
+
+ /* Gather any information for inlined functions in
+ FVEC. */
+
+ memset (&fvec, 0, sizeof fvec);
+
+ if (!read_function_entry (state, ddata, u, base, unit_buf, lhdr,
+ error_callback, data, vec_function,
+ &fvec))
+ return 0;
+
+ if (fvec.count > 0)
+ {
+ struct function_addrs *faddrs;
+
+ if (!backtrace_vector_release (state, &fvec.vec,
+ error_callback, data))
+ return 0;
+
+ faddrs = (struct function_addrs *) fvec.vec.base;
+ backtrace_qsort (faddrs, fvec.count,
+ sizeof (struct function_addrs),
+ function_addrs_compare);
+
+ function->function_addrs = faddrs;
+ function->function_addrs_count = fvec.count;
+ }
+ }
+ }
+ }
+
+ return 1;
+}
+
+/* Read function name information for a compilation unit. We look
+ through the whole unit looking for function tags. */
+
+static void
+read_function_info (struct backtrace_state *state, struct dwarf_data *ddata,
+ const struct line_header *lhdr,
+ backtrace_error_callback error_callback, void *data,
+ struct unit *u, struct function_vector *fvec,
+ struct function_addrs **ret_addrs,
+ size_t *ret_addrs_count)
+{
+ struct function_vector lvec;
+ struct function_vector *pfvec;
+ struct dwarf_buf unit_buf;
+ struct function_addrs *addrs;
+ size_t addrs_count;
+
+ /* Use FVEC if it is not NULL. Otherwise use our own vector. */
+ if (fvec != NULL)
+ pfvec = fvec;
+ else
+ {
+ memset (&lvec, 0, sizeof lvec);
+ pfvec = &lvec;
+ }
+
+ unit_buf.name = ".debug_info";
+ unit_buf.start = ddata->dwarf_info;
+ unit_buf.buf = u->unit_data;
+ unit_buf.left = u->unit_data_len;
+ unit_buf.is_bigendian = ddata->is_bigendian;
+ unit_buf.error_callback = error_callback;
+ unit_buf.data = data;
+ unit_buf.reported_underflow = 0;
+
+ while (unit_buf.left > 0)
+ {
+ if (!read_function_entry (state, ddata, u, 0, &unit_buf, lhdr,
+ error_callback, data, pfvec, pfvec))
+ return;
+ }
+
+ if (pfvec->count == 0)
+ return;
+
+ addrs_count = pfvec->count;
+
+ if (fvec == NULL)
+ {
+ if (!backtrace_vector_release (state, &lvec.vec, error_callback, data))
+ return;
+ addrs = (struct function_addrs *) pfvec->vec.base;
+ }
+ else
+ {
+ /* Finish this list of addresses, but leave the remaining space in
+ the vector available for the next function unit. */
+ addrs = ((struct function_addrs *)
+ backtrace_vector_finish (state, &fvec->vec,
+ error_callback, data));
+ if (addrs == NULL)
+ return;
+ fvec->count = 0;
+ }
+
+ backtrace_qsort (addrs, addrs_count, sizeof (struct function_addrs),
+ function_addrs_compare);
+
+ *ret_addrs = addrs;
+ *ret_addrs_count = addrs_count;
+}
+
+/* See if PC is inlined in FUNCTION. If it is, print out the inlined
+ information, and update FILENAME and LINENO for the caller.
+ Returns whatever CALLBACK returns, or 0 to keep going. */
+
+static int
+report_inlined_functions (uintptr_t pc, struct function *function,
+ backtrace_full_callback callback, void *data,
+ const char **filename, int *lineno)
+{
+ struct function_addrs *function_addrs;
+ struct function *inlined;
+ int ret;
+
+ if (function->function_addrs_count == 0)
+ return 0;
+
+ function_addrs = ((struct function_addrs *)
+ bsearch (&pc, function->function_addrs,
+ function->function_addrs_count,
+ sizeof (struct function_addrs),
+ function_addrs_search));
+ if (function_addrs == NULL)
+ return 0;
+
+ while (((size_t) (function_addrs - function->function_addrs) + 1
+ < function->function_addrs_count)
+ && pc >= (function_addrs + 1)->low
+ && pc < (function_addrs + 1)->high)
+ ++function_addrs;
+
+ /* We found an inlined call. */
+
+ inlined = function_addrs->function;
+
+ /* Report any calls inlined into this one. */
+ ret = report_inlined_functions (pc, inlined, callback, data,
+ filename, lineno);
+ if (ret != 0)
+ return ret;
+
+ /* Report this inlined call. */
+ ret = callback (data, pc, *filename, *lineno, inlined->name);
+ if (ret != 0)
+ return ret;
+
+ /* Our caller will report the caller of the inlined function; tell
+ it the appropriate filename and line number. */
+ *filename = inlined->caller_filename;
+ *lineno = inlined->caller_lineno;
+
+ return 0;
+}
+
+/* Look for a PC in the DWARF mapping for one module. On success,
+ call CALLBACK and return whatever it returns. On error, call
+ ERROR_CALLBACK and return 0. Sets *FOUND to 1 if the PC is found,
+ 0 if not. */
+
+static int
+dwarf_lookup_pc (struct backtrace_state *state, struct dwarf_data *ddata,
+ uintptr_t pc, backtrace_full_callback callback,
+ backtrace_error_callback error_callback, void *data,
+ int *found)
+{
+ struct unit_addrs *entry;
+ struct unit *u;
+ int new_data;
+ struct line *lines;
+ struct line *ln;
+ struct function_addrs *function_addrs;
+ struct function *function;
+ const char *filename;
+ int lineno;
+ int ret;
+
+ *found = 1;
+
+ /* Find an address range that includes PC. */
+ entry = bsearch (&pc, ddata->addrs, ddata->addrs_count,
+ sizeof (struct unit_addrs), unit_addrs_search);
+
+ if (entry == NULL)
+ {
+ *found = 0;
+ return 0;
+ }
+
+ /* If there are multiple ranges that contain PC, use the last one,
+ in order to produce predictable results. If we assume that all
+ ranges are properly nested, then the last range will be the
+ smallest one. */
+ while ((size_t) (entry - ddata->addrs) + 1 < ddata->addrs_count
+ && pc >= (entry + 1)->low
+ && pc < (entry + 1)->high)
+ ++entry;
+
+ /* We need the lines, lines_count, function_addrs,
+ function_addrs_count fields of u. If they are not set, we need
+ to set them. When running in threaded mode, we need to allow for
+ the possibility that some other thread is setting them
+ simultaneously. */
+
+ u = entry->u;
+ lines = u->lines;
+
+ /* Skip units with no useful line number information by walking
+ backward. Useless line number information is marked by setting
+ lines == -1. */
+ while (entry > ddata->addrs
+ && pc >= (entry - 1)->low
+ && pc < (entry - 1)->high)
+ {
+ if (state->threaded)
+ lines = (struct line *) backtrace_atomic_load_pointer (&u->lines);
+
+ if (lines != (struct line *) (uintptr_t) -1)
+ break;
+
+ --entry;
+
+ u = entry->u;
+ lines = u->lines;
+ }
+
+ if (state->threaded)
+ lines = backtrace_atomic_load_pointer (&u->lines);
+
+ new_data = 0;
+ if (lines == NULL)
+ {
+ size_t function_addrs_count;
+ struct line_header lhdr;
+ size_t count;
+
+ /* We have never read the line information for this unit. Read
+ it now. */
+
+ function_addrs = NULL;
+ function_addrs_count = 0;
+ if (read_line_info (state, ddata, error_callback, data, entry->u, &lhdr,
+ &lines, &count))
+ {
+ struct function_vector *pfvec;
+
+ /* If not threaded, reuse DDATA->FVEC for better memory
+ consumption. */
+ if (state->threaded)
+ pfvec = NULL;
+ else
+ pfvec = &ddata->fvec;
+ read_function_info (state, ddata, &lhdr, error_callback, data,
+ entry->u, pfvec, &function_addrs,
+ &function_addrs_count);
+ free_line_header (state, &lhdr, error_callback, data);
+ new_data = 1;
+ }
+
+ /* Atomically store the information we just read into the unit.
+ If another thread is simultaneously writing, it presumably
+ read the same information, and we don't care which one we
+ wind up with; we just leak the other one. We do have to
+ write the lines field last, so that the acquire-loads above
+ ensure that the other fields are set. */
+
+ if (!state->threaded)
+ {
+ u->lines_count = count;
+ u->function_addrs = function_addrs;
+ u->function_addrs_count = function_addrs_count;
+ u->lines = lines;
+ }
+ else
+ {
+ backtrace_atomic_store_size_t (&u->lines_count, count);
+ backtrace_atomic_store_pointer (&u->function_addrs, function_addrs);
+ backtrace_atomic_store_size_t (&u->function_addrs_count,
+ function_addrs_count);
+ backtrace_atomic_store_pointer (&u->lines, lines);
+ }
+ }
+
+ /* Now all fields of U have been initialized. */
+
+ if (lines == (struct line *) (uintptr_t) -1)
+ {
+ /* If reading the line number information failed in some way,
+ try again to see if there is a better compilation unit for
+ this PC. */
+ if (new_data)
+ return dwarf_lookup_pc (state, ddata, pc, callback, error_callback,
+ data, found);
+ return callback (data, pc, NULL, 0, NULL);
+ }
+
+ /* Search for PC within this unit. */
+
+ ln = (struct line *) bsearch (&pc, lines, entry->u->lines_count,
+ sizeof (struct line), line_search);
+ if (ln == NULL)
+ {
+ /* The PC is between the low_pc and high_pc attributes of the
+ compilation unit, but no entry in the line table covers it.
+ This implies that the start of the compilation unit has no
+ line number information. */
+
+ if (entry->u->abs_filename == NULL)
+ {
+ const char *filename1;
+
+ filename1 = entry->u->filename;
+ if (filename1 != NULL
+ && !IS_ABSOLUTE_PATH (filename1)
+ && entry->u->comp_dir != NULL)
+ {
+ size_t filename_len;
+ const char *dir;
+ size_t dir_len;
+ char *s;
+
+ filename_len = strlen (filename1);
+ dir = entry->u->comp_dir;
+ dir_len = strlen (dir);
+ s = (char *) backtrace_alloc (state, dir_len + filename_len + 2,
+ error_callback, data);
+ if (s == NULL)
+ {
+ *found = 0;
+ return 0;
+ }
+ memcpy (s, dir, dir_len);
+ /* FIXME: Should use backslash if DOS file system. */
+ s[dir_len] = '/';
+ memcpy (s + dir_len + 1, filename1, filename_len + 1);
+ filename1 = s;
+ }
+ entry->u->abs_filename = filename1;
+ }
+
+ return callback (data, pc, entry->u->abs_filename, 0, NULL);
+ }
+
+ /* Search for function name within this unit. */
+
+ if (entry->u->function_addrs_count == 0)
+ return callback (data, pc, ln->filename, ln->lineno, NULL);
+
+ function_addrs = ((struct function_addrs *)
+ bsearch (&pc, entry->u->function_addrs,
+ entry->u->function_addrs_count,
+ sizeof (struct function_addrs),
+ function_addrs_search));
+ if (function_addrs == NULL)
+ return callback (data, pc, ln->filename, ln->lineno, NULL);
+
+ /* If there are multiple function ranges that contain PC, use the
+ last one, in order to produce predictable results. */
+
+ while (((size_t) (function_addrs - entry->u->function_addrs + 1)
+ < entry->u->function_addrs_count)
+ && pc >= (function_addrs + 1)->low
+ && pc < (function_addrs + 1)->high)
+ ++function_addrs;
+
+ function = function_addrs->function;
+
+ filename = ln->filename;
+ lineno = ln->lineno;
+
+ ret = report_inlined_functions (pc, function, callback, data,
+ &filename, &lineno);
+ if (ret != 0)
+ return ret;
+
+ return callback (data, pc, filename, lineno, function->name);
+}
+
+
+/* Return the file/line information for a PC using the DWARF mapping
+ we built earlier. */
+
+static int
+dwarf_fileline (struct backtrace_state *state, uintptr_t pc,
+ backtrace_full_callback callback,
+ backtrace_error_callback error_callback, void *data)
+{
+ struct dwarf_data *ddata;
+ int found;
+ int ret;
+
+ if (!state->threaded)
+ {
+ for (ddata = (struct dwarf_data *) state->fileline_data;
+ ddata != NULL;
+ ddata = ddata->next)
+ {
+ ret = dwarf_lookup_pc (state, ddata, pc, callback, error_callback,
+ data, &found);
+ if (ret != 0 || found)
+ return ret;
+ }
+ }
+ else
+ {
+ struct dwarf_data **pp;
+
+ pp = (struct dwarf_data **) (void *) &state->fileline_data;
+ while (1)
+ {
+ ddata = backtrace_atomic_load_pointer (pp);
+ if (ddata == NULL)
+ break;
+
+ ret = dwarf_lookup_pc (state, ddata, pc, callback, error_callback,
+ data, &found);
+ if (ret != 0 || found)
+ return ret;
+
+ pp = &ddata->next;
+ }
+ }
+
+ /* FIXME: See if any libraries have been dlopen'ed. */
+
+ return callback (data, pc, NULL, 0, NULL);
+}
+
+/* Initialize our data structures from the DWARF debug info for a
+ file. Return NULL on failure. */
+
+static struct dwarf_data *
+build_dwarf_data (struct backtrace_state *state,
+ uintptr_t base_address,
+ const unsigned char *dwarf_info,
+ size_t dwarf_info_size,
+ const unsigned char *dwarf_line,
+ size_t dwarf_line_size,
+ const unsigned char *dwarf_abbrev,
+ size_t dwarf_abbrev_size,
+ const unsigned char *dwarf_ranges,
+ size_t dwarf_ranges_size,
+ const unsigned char *dwarf_str,
+ size_t dwarf_str_size,
+ int is_bigendian,
+ backtrace_error_callback error_callback,
+ void *data)
+{
+ struct unit_addrs_vector addrs_vec;
+ struct unit_addrs *addrs;
+ size_t addrs_count;
+ struct dwarf_data *fdata;
+
+ if (!build_address_map (state, base_address, dwarf_info, dwarf_info_size,
+ dwarf_abbrev, dwarf_abbrev_size, dwarf_ranges,
+ dwarf_ranges_size, dwarf_str, dwarf_str_size,
+ is_bigendian, error_callback, data, &addrs_vec))
+ return NULL;
+
+ if (!backtrace_vector_release (state, &addrs_vec.vec, error_callback, data))
+ return NULL;
+ addrs = (struct unit_addrs *) addrs_vec.vec.base;
+ addrs_count = addrs_vec.count;
+ backtrace_qsort (addrs, addrs_count, sizeof (struct unit_addrs),
+ unit_addrs_compare);
+
+ fdata = ((struct dwarf_data *)
+ backtrace_alloc (state, sizeof (struct dwarf_data),
+ error_callback, data));
+ if (fdata == NULL)
+ return NULL;
+
+ fdata->next = NULL;
+ fdata->base_address = base_address;
+ fdata->addrs = addrs;
+ fdata->addrs_count = addrs_count;
+ fdata->dwarf_info = dwarf_info;
+ fdata->dwarf_info_size = dwarf_info_size;
+ fdata->dwarf_line = dwarf_line;
+ fdata->dwarf_line_size = dwarf_line_size;
+ fdata->dwarf_ranges = dwarf_ranges;
+ fdata->dwarf_ranges_size = dwarf_ranges_size;
+ fdata->dwarf_str = dwarf_str;
+ fdata->dwarf_str_size = dwarf_str_size;
+ fdata->is_bigendian = is_bigendian;
+ memset (&fdata->fvec, 0, sizeof fdata->fvec);
+
+ return fdata;
+}
+
+/* Build our data structures from the DWARF sections for a module.
+ Set FILELINE_FN and STATE->FILELINE_DATA. Return 1 on success, 0
+ on failure. */
+
+int
+backtrace_dwarf_add (struct backtrace_state *state,
+ uintptr_t base_address,
+ const unsigned char *dwarf_info,
+ size_t dwarf_info_size,
+ const unsigned char *dwarf_line,
+ size_t dwarf_line_size,
+ const unsigned char *dwarf_abbrev,
+ size_t dwarf_abbrev_size,
+ const unsigned char *dwarf_ranges,
+ size_t dwarf_ranges_size,
+ const unsigned char *dwarf_str,
+ size_t dwarf_str_size,
+ int is_bigendian,
+ backtrace_error_callback error_callback,
+ void *data, fileline *fileline_fn)
+{
+ struct dwarf_data *fdata;
+
+ fdata = build_dwarf_data (state, base_address, dwarf_info, dwarf_info_size,
+ dwarf_line, dwarf_line_size, dwarf_abbrev,
+ dwarf_abbrev_size, dwarf_ranges, dwarf_ranges_size,
+ dwarf_str, dwarf_str_size, is_bigendian,
+ error_callback, data);
+ if (fdata == NULL)
+ return 0;
+
+ if (!state->threaded)
+ {
+ struct dwarf_data **pp;
+
+ for (pp = (struct dwarf_data **) (void *) &state->fileline_data;
+ *pp != NULL;
+ pp = &(*pp)->next)
+ ;
+ *pp = fdata;
+ }
+ else
+ {
+ while (1)
+ {
+ struct dwarf_data **pp;
+
+ pp = (struct dwarf_data **) (void *) &state->fileline_data;
+
+ while (1)
+ {
+ struct dwarf_data *p;
+
+ p = backtrace_atomic_load_pointer (pp);
+
+ if (p == NULL)
+ break;
+
+ pp = &p->next;
+ }
+
+ if (__sync_bool_compare_and_swap (pp, NULL, fdata))
+ break;
+ }
+ }
+
+ *fileline_fn = dwarf_fileline;
+
+ return 1;
+}