diff options
Diffstat (limited to 'libbacktrace/dwarf.c')
| -rw-r--r-- | libbacktrace/dwarf.c | 4056 |
1 files changed, 4056 insertions, 0 deletions
diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c new file mode 100644 index 0000000..e6b1f23 --- /dev/null +++ b/libbacktrace/dwarf.c @@ -0,0 +1,4056 @@ +/* dwarf.c -- Get file/line information from DWARF for backtraces. + Copyright (C) 2012-2021 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 "dwarf2.h" +#include "filenames.h" + +#include "backtrace.h" +#include "internal.h" + +#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; + /* The attribute value, for DW_FORM_implicit_const. */ + int64_t val; +}; + +/* 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 +{ + /* No attribute value. */ + ATTR_VAL_NONE, + /* An address. */ + ATTR_VAL_ADDRESS, + /* An index into the .debug_addr section, whose value is relative to + * the DW_AT_addr_base attribute of the compilation unit. */ + ATTR_VAL_ADDRESS_INDEX, + /* A unsigned integer. */ + ATTR_VAL_UINT, + /* A sigd integer. */ + ATTR_VAL_SINT, + /* A string. */ + ATTR_VAL_STRING, + /* An index into the .debug_str_offsets section. */ + ATTR_VAL_STRING_INDEX, + /* An offset to other data in the containing unit. */ + ATTR_VAL_REF_UNIT, + /* An offset to other data within the .debug_info section. */ + ATTR_VAL_REF_INFO, + /* An offset to other data within the alt .debug_info section. */ + ATTR_VAL_REF_ALT_INFO, + /* An offset to data in some other section. */ + ATTR_VAL_REF_SECTION, + /* A type signature. */ + ATTR_VAL_REF_TYPE, + /* An index into the .debug_rnglists section. */ + ATTR_VAL_RNGLISTS_INDEX, + /* 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; + /* Address size. */ + int addrsize; + /* 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; +}; + +/* A format description from a line header. */ + +struct line_header_format +{ + int lnct; /* LNCT code. */ + enum dwarf_form form; /* Form of entry data. */ +}; + +/* 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; + /* Offset of the start of the compilation unit from the start of the + .debug_info section. */ + size_t low_offset; + /* Offset of the end of the compilation unit from the start of the + .debug_info section. */ + size_t high_offset; + /* DWARF version. */ + int version; + /* Whether unit is DWARF64. */ + int is_dwarf64; + /* Address size. */ + int addrsize; + /* Offset into line number information. */ + off_t lineoff; + /* Offset of compilation unit in .debug_str_offsets. */ + uint64_t str_offsets_base; + /* Offset of compilation unit in .debug_addr. */ + uint64_t addr_base; + /* Offset of compilation unit in .debug_rnglists. */ + uint64_t rnglists_base; + /* 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; +}; + +/* A growable vector of compilation unit pointer. */ + +struct unit_vector +{ + struct backtrace_vector vec; + 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 data for .gnu_debugaltlink. */ + struct dwarf_data *altlink; + /* 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; + /* A sorted list of units. */ + struct unit **units; + /* Number of units in the list. */ + size_t units_count; + /* The unparsed DWARF debug data. */ + struct dwarf_sections dwarf_sections; + /* 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, int errnum) +{ + 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, errnum); +} + +/* 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", 0); + 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 zero-terminated string from BUF and advance past the string. */ + +static const char * +read_string (struct dwarf_buf *buf) +{ + const char *p = (const char *)buf->buf; + size_t len = strnlen (p, buf->left); + + /* - If len == left, we ran out of buffer before finding the zero terminator. + Generate an error by advancing len + 1. + - If len < left, advance by len + 1 to skip past the zero terminator. */ + size_t count = len + 1; + + if (!advance (buf, count)) + return NULL; + + return p; +} + +/* 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 24 bit value from BUF and advance 3 bytes. */ + +static uint32_t +read_uint24 (struct dwarf_buf *buf) +{ + const unsigned char *p = buf->buf; + + if (!advance (buf, 3)) + return 0; + if (buf->is_bigendian) + return (((uint32_t) p[0] << 16) | ((uint32_t) p[1] << 8) + | (uint32_t) p[2]); + else + return (((uint32_t) p[2] << 16) | ((uint32_t) p[1] << 8) + | (uint32_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", 0); + 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", 0); + 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", 0); + 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; +} + +/* Read initial_length from BUF and advance the appropriate number of bytes. */ + +static uint64_t +read_initial_length (struct dwarf_buf *buf, int *is_dwarf64) +{ + uint64_t len; + + len = read_uint32 (buf); + if (len == 0xffffffff) + { + len = read_uint64 (buf); + *is_dwarf64 = 1; + } + else + *is_dwarf64 = 0; + + return len; +} + +/* 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, uint64_t implicit_val, + struct dwarf_buf *buf, int is_dwarf64, int version, + int addrsize, const struct dwarf_sections *dwarf_sections, + struct dwarf_data *altlink, 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_data16: + val->encoding = ATTR_VAL_BLOCK; + return advance (buf, 16); + case DW_FORM_string: + val->encoding = ATTR_VAL_STRING; + val->u.string = read_string (buf); + return val->u.string == NULL ? 0 : 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_sections->size[DEBUG_STR]) + { + dwarf_buf_error (buf, "DW_FORM_strp out of range", 0); + return 0; + } + val->encoding = ATTR_VAL_STRING; + val->u.string = + (const char *) dwarf_sections->data[DEBUG_STR] + offset; + return 1; + } + case DW_FORM_line_strp: + { + uint64_t offset; + + offset = read_offset (buf, is_dwarf64); + if (offset >= dwarf_sections->size[DEBUG_LINE_STR]) + { + dwarf_buf_error (buf, "DW_FORM_line_strp out of range", 0); + return 0; + } + val->encoding = ATTR_VAL_STRING; + val->u.string = + (const char *) dwarf_sections->data[DEBUG_LINE_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 form; + + form = read_uleb128 (buf); + if (form == DW_FORM_implicit_const) + { + dwarf_buf_error (buf, + "DW_FORM_indirect to DW_FORM_implicit_const", + 0); + return 0; + } + return read_attribute ((enum dwarf_form) form, 0, buf, is_dwarf64, + version, addrsize, dwarf_sections, altlink, + 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_strx: case DW_FORM_strx1: case DW_FORM_strx2: + case DW_FORM_strx3: case DW_FORM_strx4: + { + uint64_t offset; + + switch (form) + { + case DW_FORM_strx: + offset = read_uleb128 (buf); + break; + case DW_FORM_strx1: + offset = read_byte (buf); + break; + case DW_FORM_strx2: + offset = read_uint16 (buf); + break; + case DW_FORM_strx3: + offset = read_uint24 (buf); + break; + case DW_FORM_strx4: + offset = read_uint32 (buf); + break; + default: + /* This case can't happen. */ + return 0; + } + val->encoding = ATTR_VAL_STRING_INDEX; + val->u.uint = offset; + return 1; + } + case DW_FORM_addrx: case DW_FORM_addrx1: case DW_FORM_addrx2: + case DW_FORM_addrx3: case DW_FORM_addrx4: + { + uint64_t offset; + + switch (form) + { + case DW_FORM_addrx: + offset = read_uleb128 (buf); + break; + case DW_FORM_addrx1: + offset = read_byte (buf); + break; + case DW_FORM_addrx2: + offset = read_uint16 (buf); + break; + case DW_FORM_addrx3: + offset = read_uint24 (buf); + break; + case DW_FORM_addrx4: + offset = read_uint32 (buf); + break; + default: + /* This case can't happen. */ + return 0; + } + val->encoding = ATTR_VAL_ADDRESS_INDEX; + val->u.uint = offset; + return 1; + } + case DW_FORM_ref_sup4: + val->encoding = ATTR_VAL_REF_SECTION; + val->u.uint = read_uint32 (buf); + return 1; + case DW_FORM_ref_sup8: + val->encoding = ATTR_VAL_REF_SECTION; + val->u.uint = read_uint64 (buf); + return 1; + case DW_FORM_implicit_const: + val->encoding = ATTR_VAL_UINT; + val->u.uint = implicit_val; + return 1; + case DW_FORM_loclistx: + /* We don't distinguish this from DW_FORM_sec_offset. It + * shouldn't matter since we don't care about loclists. */ + val->encoding = ATTR_VAL_REF_SECTION; + val->u.uint = read_uleb128 (buf); + return 1; + case DW_FORM_rnglistx: + val->encoding = ATTR_VAL_RNGLISTS_INDEX; + val->u.uint = read_uleb128 (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->u.uint = read_offset (buf, is_dwarf64); + if (altlink == NULL) + { + val->encoding = ATTR_VAL_NONE; + return 1; + } + val->encoding = ATTR_VAL_REF_ALT_INFO; + return 1; + case DW_FORM_strp_sup: case DW_FORM_GNU_strp_alt: + { + uint64_t offset; + + offset = read_offset (buf, is_dwarf64); + if (altlink == NULL) + { + val->encoding = ATTR_VAL_NONE; + return 1; + } + if (offset >= altlink->dwarf_sections.size[DEBUG_STR]) + { + dwarf_buf_error (buf, "DW_FORM_strp_sup out of range", 0); + return 0; + } + val->encoding = ATTR_VAL_STRING; + val->u.string = + (const char *) altlink->dwarf_sections.data[DEBUG_STR] + offset; + return 1; + } + default: + dwarf_buf_error (buf, "unrecognized DWARF form", -1); + return 0; + } +} + +/* If we can determine the value of a string attribute, set *STRING to + point to the string. Return 1 on success, 0 on error. If we don't + know the value, we consider that a success, and we don't change + *STRING. An error is only reported for some sort of out of range + offset. */ + +static int +resolve_string (const struct dwarf_sections *dwarf_sections, int is_dwarf64, + int is_bigendian, uint64_t str_offsets_base, + const struct attr_val *val, + backtrace_error_callback error_callback, void *data, + const char **string) +{ + switch (val->encoding) + { + case ATTR_VAL_STRING: + *string = val->u.string; + return 1; + + case ATTR_VAL_STRING_INDEX: + { + uint64_t offset; + struct dwarf_buf offset_buf; + + offset = val->u.uint * (is_dwarf64 ? 8 : 4) + str_offsets_base; + if (offset + (is_dwarf64 ? 8 : 4) + > dwarf_sections->size[DEBUG_STR_OFFSETS]) + { + error_callback (data, "DW_FORM_strx value out of range", 0); + return 0; + } + + offset_buf.name = ".debug_str_offsets"; + offset_buf.start = dwarf_sections->data[DEBUG_STR_OFFSETS]; + offset_buf.buf = dwarf_sections->data[DEBUG_STR_OFFSETS] + offset; + offset_buf.left = dwarf_sections->size[DEBUG_STR_OFFSETS] - offset; + offset_buf.is_bigendian = is_bigendian; + offset_buf.error_callback = error_callback; + offset_buf.data = data; + offset_buf.reported_underflow = 0; + + offset = read_offset (&offset_buf, is_dwarf64); + if (offset >= dwarf_sections->size[DEBUG_STR]) + { + dwarf_buf_error (&offset_buf, + "DW_FORM_strx offset out of range", + 0); + return 0; + } + *string = (const char *) dwarf_sections->data[DEBUG_STR] + offset; + return 1; + } + + default: + return 1; + } +} + +/* Set *ADDRESS to the real address for a ATTR_VAL_ADDRESS_INDEX. + Return 1 on success, 0 on error. */ + +static int +resolve_addr_index (const struct dwarf_sections *dwarf_sections, + uint64_t addr_base, int addrsize, int is_bigendian, + uint64_t addr_index, + backtrace_error_callback error_callback, void *data, + uint64_t *address) +{ + uint64_t offset; + struct dwarf_buf addr_buf; + + offset = addr_index * addrsize + addr_base; + if (offset + addrsize > dwarf_sections->size[DEBUG_ADDR]) + { + error_callback (data, "DW_FORM_addrx value out of range", 0); + return 0; + } + + addr_buf.name = ".debug_addr"; + addr_buf.start = dwarf_sections->data[DEBUG_ADDR]; + addr_buf.buf = dwarf_sections->data[DEBUG_ADDR] + offset; + addr_buf.left = dwarf_sections->size[DEBUG_ADDR] - offset; + addr_buf.is_bigendian = is_bigendian; + addr_buf.error_callback = error_callback; + addr_buf.data = data; + addr_buf.reported_underflow = 0; + + *address = read_address (&addr_buf, addrsize); + return 1; +} + +/* Compare a unit offset against a unit for bsearch. */ + +static int +units_search (const void *vkey, const void *ventry) +{ + const size_t *key = (const size_t *) vkey; + const struct unit *entry = *((const struct unit *const *) ventry); + size_t offset; + + offset = *key; + if (offset < entry->low_offset) + return -1; + else if (offset >= entry->high_offset) + return 1; + else + return 0; +} + +/* Find a unit in PU containing OFFSET. */ + +static struct unit * +find_unit (struct unit **pu, size_t units_count, size_t offset) +{ + struct unit **u; + u = bsearch (&offset, pu, units_count, sizeof (struct unit *), units_search); + return u == NULL ? NULL : *u; +} + +/* 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. We always + allocate an entra entry at the end of the vector, so that this + routine can safely look at the next entry. 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 + 1)->low) + return 1; + else + return 0; +} + +/* Add a new compilation unit address range to a vector. This is + called via add_ranges. Returns 1 on success, 0 on failure. */ + +static int +add_unit_addr (struct backtrace_state *state, void *rdata, + uint64_t lowpc, uint64_t highpc, + backtrace_error_callback error_callback, void *data, + void *pvec) +{ + struct unit *u = (struct unit *) rdata; + struct unit_addrs_vector *vec = (struct unit_addrs_vector *) pvec; + struct unit_addrs *p; + + /* Try to merge with the last entry. */ + if (vec->count > 0) + { + p = (struct unit_addrs *) vec->vec.base + (vec->count - 1); + if ((lowpc == p->high || lowpc == p->high + 1) + && u == p->u) + { + if (highpc > p->high) + p->high = highpc; + 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->low = lowpc; + p->high = highpc; + p->u = u; + + ++vec->count; + + return 1; +} + +/* 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. We always allocate + an entry entry at the end of the vector, so that this routine can + safely look at the next entry. 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 + 1)->low) + 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) + { + uint64_t form; + + form = read_uleb128 (&count_buf); + if ((enum dwarf_form) form == DW_FORM_implicit_const) + read_sleb128 (&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->abbrevs = ((struct abbrev *) + backtrace_alloc (state, + num_abbrevs * sizeof (struct abbrev), + error_callback, data)); + if (abbrevs->abbrevs == NULL) + return 0; + abbrevs->num_abbrevs = num_abbrevs; + 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) + { + uint64_t form; + + ++num_attrs; + form = read_uleb128 (&count_buf); + if ((enum dwarf_form) form == DW_FORM_implicit_const) + read_sleb128 (&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; + if ((enum dwarf_form) form == DW_FORM_implicit_const) + attrs[num_attrs].val = read_sleb128 (&abbrev_buf); + else + attrs[num_attrs].val = 0; + ++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; +} + +/* This struct is used to gather address range information while + reading attributes. We use this while building a mapping from + address ranges to compilation units and then again while mapping + from address ranges to function entries. Normally either + lowpc/highpc is set or ranges is set. */ + +struct pcrange { + uint64_t lowpc; /* The low PC value. */ + int have_lowpc; /* Whether a low PC value was found. */ + int lowpc_is_addr_index; /* Whether lowpc is in .debug_addr. */ + uint64_t highpc; /* The high PC value. */ + int have_highpc; /* Whether a high PC value was found. */ + int highpc_is_relative; /* Whether highpc is relative to lowpc. */ + int highpc_is_addr_index; /* Whether highpc is in .debug_addr. */ + uint64_t ranges; /* Offset in ranges section. */ + int have_ranges; /* Whether ranges is valid. */ + int ranges_is_index; /* Whether ranges is DW_FORM_rnglistx. */ +}; + +/* Update PCRANGE from an attribute value. */ + +static void +update_pcrange (const struct attr* attr, const struct attr_val* val, + struct pcrange *pcrange) +{ + switch (attr->name) + { + case DW_AT_low_pc: + if (val->encoding == ATTR_VAL_ADDRESS) + { + pcrange->lowpc = val->u.uint; + pcrange->have_lowpc = 1; + } + else if (val->encoding == ATTR_VAL_ADDRESS_INDEX) + { + pcrange->lowpc = val->u.uint; + pcrange->have_lowpc = 1; + pcrange->lowpc_is_addr_index = 1; + } + break; + + case DW_AT_high_pc: + if (val->encoding == ATTR_VAL_ADDRESS) + { + pcrange->highpc = val->u.uint; + pcrange->have_highpc = 1; + } + else if (val->encoding == ATTR_VAL_UINT) + { + pcrange->highpc = val->u.uint; + pcrange->have_highpc = 1; + pcrange->highpc_is_relative = 1; + } + else if (val->encoding == ATTR_VAL_ADDRESS_INDEX) + { + pcrange->highpc = val->u.uint; + pcrange->have_highpc = 1; + pcrange->highpc_is_addr_index = 1; + } + break; + + case DW_AT_ranges: + if (val->encoding == ATTR_VAL_UINT + || val->encoding == ATTR_VAL_REF_SECTION) + { + pcrange->ranges = val->u.uint; + pcrange->have_ranges = 1; + } + else if (val->encoding == ATTR_VAL_RNGLISTS_INDEX) + { + pcrange->ranges = val->u.uint; + pcrange->have_ranges = 1; + pcrange->ranges_is_index = 1; + } + break; + + default: + break; + } +} + +/* Call ADD_RANGE for a low/high PC pair. Returns 1 on success, 0 on + error. */ + +static int +add_low_high_range (struct backtrace_state *state, + const struct dwarf_sections *dwarf_sections, + uintptr_t base_address, int is_bigendian, + struct unit *u, const struct pcrange *pcrange, + int (*add_range) (struct backtrace_state *state, + void *rdata, uint64_t lowpc, + uint64_t highpc, + backtrace_error_callback error_callback, + void *data, void *vec), + void *rdata, + backtrace_error_callback error_callback, void *data, + void *vec) +{ + uint64_t lowpc; + uint64_t highpc; + + lowpc = pcrange->lowpc; + if (pcrange->lowpc_is_addr_index) + { + if (!resolve_addr_index (dwarf_sections, u->addr_base, u->addrsize, + is_bigendian, lowpc, error_callback, data, + &lowpc)) + return 0; + } + + highpc = pcrange->highpc; + if (pcrange->highpc_is_addr_index) + { + if (!resolve_addr_index (dwarf_sections, u->addr_base, u->addrsize, + is_bigendian, highpc, error_callback, data, + &highpc)) + return 0; + } + if (pcrange->highpc_is_relative) + highpc += lowpc; + + /* Add in the base address of the module when recording PC values, + so that we can look up the PC directly. */ + lowpc += base_address; + highpc += base_address; + + return add_range (state, rdata, lowpc, highpc, error_callback, data, vec); +} + +/* Call ADD_RANGE for each range read from .debug_ranges, as used in + DWARF versions 2 through 4. */ + +static int +add_ranges_from_ranges ( + struct backtrace_state *state, + const struct dwarf_sections *dwarf_sections, + uintptr_t base_address, int is_bigendian, + struct unit *u, uint64_t base, + const struct pcrange *pcrange, + int (*add_range) (struct backtrace_state *state, void *rdata, + uint64_t lowpc, uint64_t highpc, + backtrace_error_callback error_callback, void *data, + void *vec), + void *rdata, + backtrace_error_callback error_callback, void *data, + void *vec) +{ + struct dwarf_buf ranges_buf; + + if (pcrange->ranges >= dwarf_sections->size[DEBUG_RANGES]) + { + error_callback (data, "ranges offset out of range", 0); + return 0; + } + + ranges_buf.name = ".debug_ranges"; + ranges_buf.start = dwarf_sections->data[DEBUG_RANGES]; + ranges_buf.buf = dwarf_sections->data[DEBUG_RANGES] + pcrange->ranges; + ranges_buf.left = dwarf_sections->size[DEBUG_RANGES] - pcrange->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 + { + if (!add_range (state, rdata, + low + base + base_address, + high + base + base_address, + error_callback, data, vec)) + return 0; + } + } + + if (ranges_buf.reported_underflow) + return 0; + + return 1; +} + +/* Call ADD_RANGE for each range read from .debug_rnglists, as used in + DWARF version 5. */ + +static int +add_ranges_from_rnglists ( + struct backtrace_state *state, + const struct dwarf_sections *dwarf_sections, + uintptr_t base_address, int is_bigendian, + struct unit *u, uint64_t base, + const struct pcrange *pcrange, + int (*add_range) (struct backtrace_state *state, void *rdata, + uint64_t lowpc, uint64_t highpc, + backtrace_error_callback error_callback, void *data, + void *vec), + void *rdata, + backtrace_error_callback error_callback, void *data, + void *vec) +{ + uint64_t offset; + struct dwarf_buf rnglists_buf; + + if (!pcrange->ranges_is_index) + offset = pcrange->ranges; + else + offset = u->rnglists_base + pcrange->ranges * (u->is_dwarf64 ? 8 : 4); + if (offset >= dwarf_sections->size[DEBUG_RNGLISTS]) + { + error_callback (data, "rnglists offset out of range", 0); + return 0; + } + + rnglists_buf.name = ".debug_rnglists"; + rnglists_buf.start = dwarf_sections->data[DEBUG_RNGLISTS]; + rnglists_buf.buf = dwarf_sections->data[DEBUG_RNGLISTS] + offset; + rnglists_buf.left = dwarf_sections->size[DEBUG_RNGLISTS] - offset; + rnglists_buf.is_bigendian = is_bigendian; + rnglists_buf.error_callback = error_callback; + rnglists_buf.data = data; + rnglists_buf.reported_underflow = 0; + + if (pcrange->ranges_is_index) + { + offset = read_offset (&rnglists_buf, u->is_dwarf64); + offset += u->rnglists_base; + if (offset >= dwarf_sections->size[DEBUG_RNGLISTS]) + { + error_callback (data, "rnglists index offset out of range", 0); + return 0; + } + rnglists_buf.buf = dwarf_sections->data[DEBUG_RNGLISTS] + offset; + rnglists_buf.left = dwarf_sections->size[DEBUG_RNGLISTS] - offset; + } + + while (1) + { + unsigned char rle; + + rle = read_byte (&rnglists_buf); + if (rle == DW_RLE_end_of_list) + break; + switch (rle) + { + case DW_RLE_base_addressx: + { + uint64_t index; + + index = read_uleb128 (&rnglists_buf); + if (!resolve_addr_index (dwarf_sections, u->addr_base, + u->addrsize, is_bigendian, index, + error_callback, data, &base)) + return 0; + } + break; + + case DW_RLE_startx_endx: + { + uint64_t index; + uint64_t low; + uint64_t high; + + index = read_uleb128 (&rnglists_buf); + if (!resolve_addr_index (dwarf_sections, u->addr_base, + u->addrsize, is_bigendian, index, + error_callback, data, &low)) + return 0; + index = read_uleb128 (&rnglists_buf); + if (!resolve_addr_index (dwarf_sections, u->addr_base, + u->addrsize, is_bigendian, index, + error_callback, data, &high)) + return 0; + if (!add_range (state, rdata, low + base_address, + high + base_address, error_callback, data, + vec)) + return 0; + } + break; + + case DW_RLE_startx_length: + { + uint64_t index; + uint64_t low; + uint64_t length; + + index = read_uleb128 (&rnglists_buf); + if (!resolve_addr_index (dwarf_sections, u->addr_base, + u->addrsize, is_bigendian, index, + error_callback, data, &low)) + return 0; + length = read_uleb128 (&rnglists_buf); + low += base_address; + if (!add_range (state, rdata, low, low + length, + error_callback, data, vec)) + return 0; + } + break; + + case DW_RLE_offset_pair: + { + uint64_t low; + uint64_t high; + + low = read_uleb128 (&rnglists_buf); + high = read_uleb128 (&rnglists_buf); + if (!add_range (state, rdata, low + base + base_address, + high + base + base_address, + error_callback, data, vec)) + return 0; + } + break; + + case DW_RLE_base_address: + base = read_address (&rnglists_buf, u->addrsize); + break; + + case DW_RLE_start_end: + { + uint64_t low; + uint64_t high; + + low = read_address (&rnglists_buf, u->addrsize); + high = read_address (&rnglists_buf, u->addrsize); + if (!add_range (state, rdata, low + base_address, + high + base_address, error_callback, data, + vec)) + return 0; + } + break; + + case DW_RLE_start_length: + { + uint64_t low; + uint64_t length; + + low = read_address (&rnglists_buf, u->addrsize); + length = read_uleb128 (&rnglists_buf); + low += base_address; + if (!add_range (state, rdata, low, low + length, + error_callback, data, vec)) + return 0; + } + break; + + default: + dwarf_buf_error (&rnglists_buf, "unrecognized DW_RLE value", -1); + return 0; + } + } + + if (rnglists_buf.reported_underflow) + return 0; + + return 1; +} + +/* Call ADD_RANGE for each lowpc/highpc pair in PCRANGE. RDATA is + passed to ADD_RANGE, and is either a struct unit * or a struct + function *. VEC is the vector we are adding ranges to, and is + either a struct unit_addrs_vector * or a struct function_vector *. + Returns 1 on success, 0 on error. */ + +static int +add_ranges (struct backtrace_state *state, + const struct dwarf_sections *dwarf_sections, + uintptr_t base_address, int is_bigendian, + struct unit *u, uint64_t base, const struct pcrange *pcrange, + int (*add_range) (struct backtrace_state *state, void *rdata, + uint64_t lowpc, uint64_t highpc, + backtrace_error_callback error_callback, + void *data, void *vec), + void *rdata, + backtrace_error_callback error_callback, void *data, + void *vec) +{ + if (pcrange->have_lowpc && pcrange->have_highpc) + return add_low_high_range (state, dwarf_sections, base_address, + is_bigendian, u, pcrange, add_range, rdata, + error_callback, data, vec); + + if (!pcrange->have_ranges) + { + /* Did not find any address ranges to add. */ + return 1; + } + + if (u->version < 5) + return add_ranges_from_ranges (state, dwarf_sections, base_address, + is_bigendian, u, base, pcrange, add_range, + rdata, error_callback, data, vec); + else + return add_ranges_from_rnglists (state, dwarf_sections, base_address, + is_bigendian, u, base, pcrange, add_range, + rdata, error_callback, data, vec); +} + +/* 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 struct dwarf_sections *dwarf_sections, + int is_bigendian, struct dwarf_data *altlink, + backtrace_error_callback error_callback, void *data, + struct unit *u, struct unit_addrs_vector *addrs, + enum dwarf_tag *unit_tag) +{ + while (unit_buf->left > 0) + { + uint64_t code; + const struct abbrev *abbrev; + struct pcrange pcrange; + struct attr_val name_val; + int have_name_val; + struct attr_val comp_dir_val; + int have_comp_dir_val; + 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; + + if (unit_tag != NULL) + *unit_tag = abbrev->tag; + + memset (&pcrange, 0, sizeof pcrange); + memset (&name_val, 0, sizeof name_val); + have_name_val = 0; + memset (&comp_dir_val, 0, sizeof comp_dir_val); + have_comp_dir_val = 0; + for (i = 0; i < abbrev->num_attrs; ++i) + { + struct attr_val val; + + if (!read_attribute (abbrev->attrs[i].form, abbrev->attrs[i].val, + unit_buf, u->is_dwarf64, u->version, + u->addrsize, dwarf_sections, altlink, &val)) + return 0; + + switch (abbrev->attrs[i].name) + { + case DW_AT_low_pc: case DW_AT_high_pc: case DW_AT_ranges: + update_pcrange (&abbrev->attrs[i], &val, &pcrange); + 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) + { + name_val = val; + have_name_val = 1; + } + break; + + case DW_AT_comp_dir: + if (abbrev->tag == DW_TAG_compile_unit) + { + comp_dir_val = val; + have_comp_dir_val = 1; + } + break; + + case DW_AT_str_offsets_base: + if (abbrev->tag == DW_TAG_compile_unit + && val.encoding == ATTR_VAL_REF_SECTION) + u->str_offsets_base = val.u.uint; + break; + + case DW_AT_addr_base: + if (abbrev->tag == DW_TAG_compile_unit + && val.encoding == ATTR_VAL_REF_SECTION) + u->addr_base = val.u.uint; + break; + + case DW_AT_rnglists_base: + if (abbrev->tag == DW_TAG_compile_unit + && val.encoding == ATTR_VAL_REF_SECTION) + u->rnglists_base = val.u.uint; + break; + + default: + break; + } + } + + // Resolve strings after we're sure that we have seen + // DW_AT_str_offsets_base. + if (have_name_val) + { + if (!resolve_string (dwarf_sections, u->is_dwarf64, is_bigendian, + u->str_offsets_base, &name_val, + error_callback, data, &u->filename)) + return 0; + } + if (have_comp_dir_val) + { + if (!resolve_string (dwarf_sections, u->is_dwarf64, is_bigendian, + u->str_offsets_base, &comp_dir_val, + error_callback, data, &u->comp_dir)) + return 0; + } + + if (abbrev->tag == DW_TAG_compile_unit + || abbrev->tag == DW_TAG_subprogram) + { + if (!add_ranges (state, dwarf_sections, base_address, + is_bigendian, u, pcrange.lowpc, &pcrange, + add_unit_addr, (void *) u, error_callback, data, + (void *) 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 + && (pcrange.have_ranges + || (pcrange.have_lowpc && pcrange.have_highpc))) + return 1; + } + + if (abbrev->has_children) + { + if (!find_address_ranges (state, base_address, unit_buf, + dwarf_sections, is_bigendian, altlink, + error_callback, data, u, addrs, NULL)) + 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 struct dwarf_sections *dwarf_sections, + int is_bigendian, struct dwarf_data *altlink, + backtrace_error_callback error_callback, void *data, + struct unit_addrs_vector *addrs, + struct unit_vector *unit_vec) +{ + struct dwarf_buf info; + struct backtrace_vector units; + size_t units_count; + size_t i; + struct unit **pu; + size_t unit_offset = 0; + struct unit_addrs *pa; + + memset (&addrs->vec, 0, sizeof addrs->vec); + memset (&unit_vec->vec, 0, sizeof unit_vec->vec); + addrs->count = 0; + unit_vec->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_sections->data[DEBUG_INFO]; + info.buf = info.start; + info.left = dwarf_sections->size[DEBUG_INFO]; + info.is_bigendian = is_bigendian; + info.error_callback = error_callback; + info.data = data; + info.reported_underflow = 0; + + memset (&units, 0, sizeof units); + units_count = 0; + + while (info.left > 0) + { + const unsigned char *unit_data_start; + uint64_t len; + int is_dwarf64; + struct dwarf_buf unit_buf; + int version; + int unit_type; + uint64_t abbrev_offset; + int addrsize; + struct unit *u; + enum dwarf_tag unit_tag; + + if (info.reported_underflow) + goto fail; + + unit_data_start = info.buf; + + len = read_initial_length (&info, &is_dwarf64); + unit_buf = info; + unit_buf.left = len; + + if (!advance (&info, len)) + goto fail; + + version = read_uint16 (&unit_buf); + if (version < 2 || version > 5) + { + dwarf_buf_error (&unit_buf, "unrecognized DWARF version", -1); + goto fail; + } + + if (version < 5) + unit_type = 0; + else + { + unit_type = read_byte (&unit_buf); + if (unit_type == DW_UT_type || unit_type == DW_UT_split_type) + { + /* This unit doesn't have anything we need. */ + continue; + } + } + + pu = ((struct unit **) + backtrace_vector_grow (state, sizeof (struct unit *), + error_callback, data, &units)); + if (pu == NULL) + goto fail; + + u = ((struct unit *) + backtrace_alloc (state, sizeof *u, error_callback, data)); + if (u == NULL) + goto fail; + + *pu = u; + ++units_count; + + if (version < 5) + addrsize = 0; /* Set below. */ + else + addrsize = read_byte (&unit_buf); + + memset (&u->abbrevs, 0, sizeof u->abbrevs); + abbrev_offset = read_offset (&unit_buf, is_dwarf64); + if (!read_abbrevs (state, abbrev_offset, + dwarf_sections->data[DEBUG_ABBREV], + dwarf_sections->size[DEBUG_ABBREV], + is_bigendian, error_callback, data, &u->abbrevs)) + goto fail; + + if (version < 5) + addrsize = read_byte (&unit_buf); + + switch (unit_type) + { + case 0: + break; + case DW_UT_compile: case DW_UT_partial: + break; + case DW_UT_skeleton: case DW_UT_split_compile: + read_uint64 (&unit_buf); /* dwo_id */ + break; + default: + break; + } + + u->low_offset = unit_offset; + unit_offset += len + (is_dwarf64 ? 12 : 4); + u->high_offset = unit_offset; + 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; + + /* 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_sections, + is_bigendian, altlink, error_callback, data, + u, addrs, &unit_tag)) + goto fail; + + if (unit_buf.reported_underflow) + goto fail; + } + if (info.reported_underflow) + goto fail; + + /* Add a trailing addrs entry, but don't include it in addrs->count. */ + pa = ((struct unit_addrs *) + backtrace_vector_grow (state, sizeof (struct unit_addrs), + error_callback, data, &addrs->vec)); + if (pa == NULL) + goto fail; + pa->low = 0; + --pa->low; + pa->high = pa->low; + pa->u = NULL; + + unit_vec->vec = units; + unit_vec->count = units_count; + return 1; + + fail: + if (units_count > 0) + { + pu = (struct unit **) units.base; + for (i = 0; i < units_count; i++) + { + free_abbrevs (state, &pu[i]->abbrevs, error_callback, data); + backtrace_free (state, pu[i], sizeof **pu, error_callback, data); + } + backtrace_vector_free (state, &units, error_callback, data); + } + if (addrs->count > 0) + { + backtrace_vector_free (state, &addrs->vec, error_callback, data); + addrs->count = 0; + } + 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 = 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 directories and file names for a line header for version + 2, setting fields in HDR. Return 1 on success, 0 on failure. */ + +static int +read_v2_paths (struct backtrace_state *state, struct unit *u, + struct dwarf_buf *hdr_buf, struct line_header *hdr) +{ + const unsigned char *p; + const unsigned char *pend; + size_t i; + + /* 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; + } + + /* The index of the first entry in the list of directories is 1. Index 0 is + used for the current directory of the compilation. To simplify index + handling, we set entry 0 to the compilation unit directory. */ + ++hdr->dirs_count; + hdr->dirs = ((const char **) + backtrace_alloc (state, + hdr->dirs_count * sizeof (const char *), + hdr_buf->error_callback, + hdr_buf->data)); + if (hdr->dirs == NULL) + return 0; + + hdr->dirs[0] = u->comp_dir; + i = 1; + while (*hdr_buf->buf != '\0') + { + if (hdr_buf->reported_underflow) + return 0; + + hdr->dirs[i] = read_string (hdr_buf); + if (hdr->dirs[i] == NULL) + return 0; + ++i; + } + 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; + } + + /* The index of the first entry in the list of file names is 1. Index 0 is + used for the DW_AT_name of the compilation unit. To simplify index + handling, we set entry 0 to the compilation unit file name. */ + ++hdr->filenames_count; + hdr->filenames = ((const char **) + backtrace_alloc (state, + hdr->filenames_count * sizeof (char *), + hdr_buf->error_callback, + hdr_buf->data)); + if (hdr->filenames == NULL) + return 0; + hdr->filenames[0] = u->filename; + i = 1; + while (*hdr_buf->buf != '\0') + { + const char *filename; + uint64_t dir_index; + + if (hdr_buf->reported_underflow) + return 0; + + filename = read_string (hdr_buf); + if (filename == NULL) + return 0; + dir_index = read_uleb128 (hdr_buf); + if (IS_ABSOLUTE_PATH (filename) + || (dir_index < hdr->dirs_count && hdr->dirs[dir_index] == NULL)) + hdr->filenames[i] = filename; + else + { + const char *dir; + size_t dir_len; + size_t filename_len; + char *s; + + if (dir_index < hdr->dirs_count) + dir = hdr->dirs[dir_index]; + else + { + dwarf_buf_error (hdr_buf, + ("invalid directory index in " + "line number program header"), + 0); + return 0; + } + dir_len = strlen (dir); + filename_len = strlen (filename); + s = ((char *) backtrace_alloc (state, dir_len + filename_len + 2, + hdr_buf->error_callback, + hdr_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; + } + + return 1; +} + +/* Read a single version 5 LNCT entry for a directory or file name in a + line header. Sets *STRING to the resulting name, ignoring other + data. Return 1 on success, 0 on failure. */ + +static int +read_lnct (struct backtrace_state *state, struct dwarf_data *ddata, + struct unit *u, struct dwarf_buf *hdr_buf, + const struct line_header *hdr, size_t formats_count, + const struct line_header_format *formats, const char **string) +{ + size_t i; + const char *dir; + const char *path; + + dir = NULL; + path = NULL; + for (i = 0; i < formats_count; i++) + { + struct attr_val val; + + if (!read_attribute (formats[i].form, 0, hdr_buf, u->is_dwarf64, + u->version, hdr->addrsize, &ddata->dwarf_sections, + ddata->altlink, &val)) + return 0; + switch (formats[i].lnct) + { + case DW_LNCT_path: + if (!resolve_string (&ddata->dwarf_sections, u->is_dwarf64, + ddata->is_bigendian, u->str_offsets_base, + &val, hdr_buf->error_callback, hdr_buf->data, + &path)) + return 0; + break; + case DW_LNCT_directory_index: + if (val.encoding == ATTR_VAL_UINT) + { + if (val.u.uint >= hdr->dirs_count) + { + dwarf_buf_error (hdr_buf, + ("invalid directory index in " + "line number program header"), + 0); + return 0; + } + dir = hdr->dirs[val.u.uint]; + } + break; + default: + /* We don't care about timestamps or sizes or hashes. */ + break; + } + } + + if (path == NULL) + { + dwarf_buf_error (hdr_buf, + "missing file name in line number program header", + 0); + return 0; + } + + if (dir == NULL) + *string = path; + else + { + size_t dir_len; + size_t path_len; + char *s; + + dir_len = strlen (dir); + path_len = strlen (path); + s = (char *) backtrace_alloc (state, dir_len + path_len + 2, + hdr_buf->error_callback, hdr_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 path name use backslashes, then we should + use a backslash here. */ + s[dir_len] = '/'; + memcpy (s + dir_len + 1, path, path_len + 1); + *string = s; + } + + return 1; +} + +/* Read a set of DWARF 5 line header format entries, setting *PCOUNT + and *PPATHS. Return 1 on success, 0 on failure. */ + +static int +read_line_header_format_entries (struct backtrace_state *state, + struct dwarf_data *ddata, + struct unit *u, + struct dwarf_buf *hdr_buf, + struct line_header *hdr, + size_t *pcount, + const char ***ppaths) +{ + size_t formats_count; + struct line_header_format *formats; + size_t paths_count; + const char **paths; + size_t i; + int ret; + + formats_count = read_byte (hdr_buf); + if (formats_count == 0) + formats = NULL; + else + { + formats = ((struct line_header_format *) + backtrace_alloc (state, + (formats_count + * sizeof (struct line_header_format)), + hdr_buf->error_callback, + hdr_buf->data)); + if (formats == NULL) + return 0; + + for (i = 0; i < formats_count; i++) + { + formats[i].lnct = (int) read_uleb128(hdr_buf); + formats[i].form = (enum dwarf_form) read_uleb128 (hdr_buf); + } + } + + paths_count = read_uleb128 (hdr_buf); + if (paths_count == 0) + { + *pcount = 0; + *ppaths = NULL; + ret = 1; + goto exit; + } + + paths = ((const char **) + backtrace_alloc (state, paths_count * sizeof (const char *), + hdr_buf->error_callback, hdr_buf->data)); + if (paths == NULL) + { + ret = 0; + goto exit; + } + for (i = 0; i < paths_count; i++) + { + if (!read_lnct (state, ddata, u, hdr_buf, hdr, formats_count, + formats, &paths[i])) + { + backtrace_free (state, paths, + paths_count * sizeof (const char *), + hdr_buf->error_callback, hdr_buf->data); + ret = 0; + goto exit; + } + } + + *pcount = paths_count; + *ppaths = paths; + + ret = 1; + + exit: + if (formats != NULL) + backtrace_free (state, formats, + formats_count * sizeof (struct line_header_format), + hdr_buf->error_callback, hdr_buf->data); + + return ret; +} + +/* Read the line header. Return 1 on success, 0 on failure. */ + +static int +read_line_header (struct backtrace_state *state, struct dwarf_data *ddata, + struct unit *u, int is_dwarf64, struct dwarf_buf *line_buf, + struct line_header *hdr) +{ + uint64_t hdrlen; + struct dwarf_buf hdr_buf; + + hdr->version = read_uint16 (line_buf); + if (hdr->version < 2 || hdr->version > 5) + { + dwarf_buf_error (line_buf, "unsupported line number version", -1); + return 0; + } + + if (hdr->version < 5) + hdr->addrsize = u->addrsize; + else + { + hdr->addrsize = read_byte (line_buf); + /* We could support a non-zero segment_selector_size but I doubt + we'll ever see it. */ + if (read_byte (line_buf) != 0) + { + dwarf_buf_error (line_buf, + "non-zero segment_selector_size not supported", + -1); + 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; + + if (hdr->version < 5) + { + if (!read_v2_paths (state, u, &hdr_buf, hdr)) + return 0; + } + else + { + if (!read_line_header_format_entries (state, ddata, u, &hdr_buf, hdr, + &hdr->dirs_count, + &hdr->dirs)) + return 0; + if (!read_line_header_format_entries (state, ddata, u, &hdr_buf, hdr, + &hdr->filenames_count, + &hdr->filenames)) + return 0; + } + + 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, + 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 > 1) + reset_filename = hdr->filenames[1]; + 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, hdr->addrsize); + break; + case DW_LNE_define_file: + { + const char *f; + unsigned int dir_index; + + f = read_string (line_buf); + if (f == NULL) + return 0; + dir_index = 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 < hdr->dirs_count) + dir = hdr->dirs[dir_index]; + else + { + dwarf_buf_error (line_buf, + ("invalid directory index " + "in line number program"), + 0); + 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 >= hdr->filenames_count) + { + dwarf_buf_error (line_buf, + ("invalid file number in " + "line number program"), + 0); + return 0; + } + filename = hdr->filenames[fileno]; + } + 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_sections.size[DEBUG_LINE]) + { + error_callback (data, "unit line offset out of range", 0); + goto fail; + } + + line_buf.name = ".debug_line"; + line_buf.start = ddata->dwarf_sections.data[DEBUG_LINE]; + line_buf.buf = ddata->dwarf_sections.data[DEBUG_LINE] + u->lineoff; + line_buf.left = ddata->dwarf_sections.size[DEBUG_LINE] - u->lineoff; + line_buf.is_bigendian = ddata->is_bigendian; + line_buf.error_callback = error_callback; + line_buf.data = data; + line_buf.reported_underflow = 0; + + len = read_initial_length (&line_buf, &is_dwarf64); + line_buf.left = len; + + if (!read_line_header (state, ddata, u, is_dwarf64, &line_buf, hdr)) + goto fail; + + if (!read_line_program (state, ddata, 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: + backtrace_vector_free (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; +} + +static const char *read_referenced_name (struct dwarf_data *, struct unit *, + uint64_t, backtrace_error_callback, + void *); + +/* Read the name of a function from a DIE referenced by ATTR with VAL. */ + +static const char * +read_referenced_name_from_attr (struct dwarf_data *ddata, struct unit *u, + struct attr *attr, struct attr_val *val, + backtrace_error_callback error_callback, + void *data) +{ + switch (attr->name) + { + case DW_AT_abstract_origin: + case DW_AT_specification: + break; + default: + return NULL; + } + + if (attr->form == DW_FORM_ref_sig8) + return NULL; + + if (val->encoding == ATTR_VAL_REF_INFO) + { + struct unit *unit + = find_unit (ddata->units, ddata->units_count, + val->u.uint); + if (unit == NULL) + return NULL; + + uint64_t offset = val->u.uint - unit->low_offset; + return read_referenced_name (ddata, unit, offset, error_callback, data); + } + + if (val->encoding == ATTR_VAL_UINT + || val->encoding == ATTR_VAL_REF_UNIT) + return read_referenced_name (ddata, u, val->u.uint, error_callback, data); + + if (val->encoding == ATTR_VAL_REF_ALT_INFO) + { + struct unit *alt_unit + = find_unit (ddata->altlink->units, ddata->altlink->units_count, + val->u.uint); + if (alt_unit == NULL) + return NULL; + + uint64_t offset = val->u.uint - alt_unit->low_offset; + return read_referenced_name (ddata->altlink, alt_unit, offset, + error_callback, data); + } + + return NULL; +} + +/* 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_sections.data[DEBUG_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", + 0); + 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, abbrev->attrs[i].val, + &unit_buf, u->is_dwarf64, u->version, u->addrsize, + &ddata->dwarf_sections, ddata->altlink, &val)) + return NULL; + + switch (abbrev->attrs[i].name) + { + case DW_AT_name: + /* Third name preference: don't override. A name we found in some + other way, will normally be more useful -- e.g., this name is + normally not mangled. */ + if (ret != NULL) + break; + if (!resolve_string (&ddata->dwarf_sections, u->is_dwarf64, + ddata->is_bigendian, u->str_offsets_base, + &val, error_callback, data, &ret)) + return NULL; + break; + + case DW_AT_linkage_name: + case DW_AT_MIPS_linkage_name: + /* First name preference: override all. */ + { + const char *s; + + s = NULL; + if (!resolve_string (&ddata->dwarf_sections, u->is_dwarf64, + ddata->is_bigendian, u->str_offsets_base, + &val, error_callback, data, &s)) + return NULL; + if (s != NULL) + return s; + } + break; + + case DW_AT_specification: + /* Second name preference: override DW_AT_name, don't override + DW_AT_linkage_name. */ + { + const char *name; + + name = read_referenced_name_from_attr (ddata, u, &abbrev->attrs[i], + &val, error_callback, data); + if (name != NULL) + ret = name; + } + break; + + default: + break; + } + } + + return ret; +} + +/* Add a range to a unit that maps to a function. This is called via + add_ranges. Returns 1 on success, 0 on error. */ + +static int +add_function_range (struct backtrace_state *state, void *rdata, + uint64_t lowpc, uint64_t highpc, + backtrace_error_callback error_callback, void *data, + void *pvec) +{ + struct function *function = (struct function *) rdata; + struct function_vector *vec = (struct function_vector *) pvec; + struct function_addrs *p; + + 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; +} + +/* 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; + struct pcrange pcrange; + int have_linkage_name; + + 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); + } + + memset (&pcrange, 0, sizeof pcrange); + have_linkage_name = 0; + for (i = 0; i < abbrev->num_attrs; ++i) + { + struct attr_val val; + + if (!read_attribute (abbrev->attrs[i].form, abbrev->attrs[i].val, + unit_buf, u->is_dwarf64, u->version, + u->addrsize, &ddata->dwarf_sections, + ddata->altlink, &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) + { + if (val.encoding == ATTR_VAL_ADDRESS) + base = val.u.uint; + else if (val.encoding == ATTR_VAL_ADDRESS_INDEX) + { + if (!resolve_addr_index (&ddata->dwarf_sections, + u->addr_base, u->addrsize, + ddata->is_bigendian, val.u.uint, + error_callback, data, &base)) + return 0; + } + } + + if (is_function) + { + switch (abbrev->attrs[i].name) + { + case DW_AT_call_file: + if (val.encoding == ATTR_VAL_UINT) + { + if (val.u.uint >= lhdr->filenames_count) + { + dwarf_buf_error (unit_buf, + ("invalid file number in " + "DW_AT_call_file attribute"), + 0); + return 0; + } + function->caller_filename = lhdr->filenames[val.u.uint]; + } + break; + + case DW_AT_call_line: + if (val.encoding == ATTR_VAL_UINT) + function->caller_lineno = val.u.uint; + break; + + case DW_AT_abstract_origin: + case DW_AT_specification: + /* Second name preference: override DW_AT_name, don't override + DW_AT_linkage_name. */ + if (have_linkage_name) + break; + { + const char *name; + + name + = read_referenced_name_from_attr (ddata, u, + &abbrev->attrs[i], &val, + error_callback, data); + if (name != NULL) + function->name = name; + } + break; + + case DW_AT_name: + /* Third name preference: don't override. */ + if (function->name != NULL) + break; + if (!resolve_string (&ddata->dwarf_sections, u->is_dwarf64, + ddata->is_bigendian, + u->str_offsets_base, &val, + error_callback, data, &function->name)) + return 0; + break; + + case DW_AT_linkage_name: + case DW_AT_MIPS_linkage_name: + /* First name preference: override all. */ + { + const char *s; + + s = NULL; + if (!resolve_string (&ddata->dwarf_sections, u->is_dwarf64, + ddata->is_bigendian, + u->str_offsets_base, &val, + error_callback, data, &s)) + return 0; + if (s != NULL) + { + function->name = s; + have_linkage_name = 1; + } + } + break; + + case DW_AT_low_pc: case DW_AT_high_pc: case DW_AT_ranges: + update_pcrange (&abbrev->attrs[i], &val, &pcrange); + 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 (pcrange.have_ranges + || (pcrange.have_lowpc && pcrange.have_highpc)) + { + if (!add_ranges (state, &ddata->dwarf_sections, + ddata->base_address, ddata->is_bigendian, + u, base, &pcrange, add_function_range, + (void *) function, error_callback, data, + (void *) 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 *p; + struct function_addrs *faddrs; + + /* Allocate a trailing entry, but don't include it + in fvec.count. */ + p = ((struct function_addrs *) + backtrace_vector_grow (state, + sizeof (struct function_addrs), + error_callback, data, + &fvec.vec)); + if (p == NULL) + return 0; + p->low = 0; + --p->low; + p->high = p->low; + p->function = NULL; + + 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 *p; + 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_sections.data[DEBUG_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; + + /* Allocate a trailing entry, but don't include it in + pfvec->count. */ + p = ((struct function_addrs *) + backtrace_vector_grow (state, sizeof (struct function_addrs), + error_callback, data, &pfvec->vec)); + if (p == NULL) + return; + p->low = 0; + --p->low; + p->high = p->low; + p->function = NULL; + + 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 *p; + struct function_addrs *match; + struct function *inlined; + int ret; + + if (function->function_addrs_count == 0) + return 0; + + /* Our search isn't safe if pc == -1, as that is the sentinel + value. */ + if (pc + 1 == 0) + return 0; + + p = ((struct function_addrs *) + bsearch (&pc, function->function_addrs, + function->function_addrs_count, + sizeof (struct function_addrs), + function_addrs_search)); + if (p == NULL) + return 0; + + /* Here pc >= p->low && pc < (p + 1)->low. The function_addrs are + sorted by low, so if pc > p->low we are at the end of a range of + function_addrs with the same low value. If pc == p->low walk + forward to the end of the range with that low value. Then walk + backward and use the first range that includes pc. */ + while (pc == (p + 1)->low) + ++p; + match = NULL; + while (1) + { + if (pc < p->high) + { + match = p; + break; + } + if (p == function->function_addrs) + break; + if ((p - 1)->low < p->low) + break; + --p; + } + if (match == NULL) + return 0; + + /* We found an inlined call. */ + + inlined = match->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; + int found_entry; + struct unit *u; + int new_data; + struct line *lines; + struct line *ln; + struct function_addrs *p; + struct function_addrs *fmatch; + struct function *function; + const char *filename; + int lineno; + int ret; + + *found = 1; + + /* Find an address range that includes PC. Our search isn't safe if + PC == -1, as we use that as a sentinel value, so skip the search + in that case. */ + entry = (ddata->addrs_count == 0 || pc + 1 == 0 + ? NULL + : bsearch (&pc, ddata->addrs, ddata->addrs_count, + sizeof (struct unit_addrs), unit_addrs_search)); + + if (entry == NULL) + { + *found = 0; + return 0; + } + + /* Here pc >= entry->low && pc < (entry + 1)->low. The unit_addrs + are sorted by low, so if pc > p->low we are at the end of a range + of unit_addrs with the same low value. If pc == p->low walk + forward to the end of the range with that low value. Then walk + backward and use the first range that includes pc. */ + while (pc == (entry + 1)->low) + ++entry; + found_entry = 0; + while (1) + { + if (pc < entry->high) + { + found_entry = 1; + break; + } + if (entry == ddata->addrs) + break; + if ((entry - 1)->low < entry->low) + break; + --entry; + } + if (!found_entry) + { + *found = 0; + return 0; + } + + /* 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) + { + struct function_addrs *function_addrs; + 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 *filename; + + filename = entry->u->filename; + if (filename != NULL + && !IS_ABSOLUTE_PATH (filename) + && entry->u->comp_dir != NULL) + { + size_t filename_len; + const char *dir; + size_t dir_len; + char *s; + + filename_len = strlen (filename); + 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, filename, filename_len + 1); + filename = s; + } + entry->u->abs_filename = filename; + } + + 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); + + p = ((struct function_addrs *) + bsearch (&pc, entry->u->function_addrs, + entry->u->function_addrs_count, + sizeof (struct function_addrs), + function_addrs_search)); + if (p == NULL) + return callback (data, pc, ln->filename, ln->lineno, NULL); + + /* Here pc >= p->low && pc < (p + 1)->low. The function_addrs are + sorted by low, so if pc > p->low we are at the end of a range of + function_addrs with the same low value. If pc == p->low walk + forward to the end of the range with that low value. Then walk + backward and use the first range that includes pc. */ + while (pc == (p + 1)->low) + ++p; + fmatch = NULL; + while (1) + { + if (pc < p->high) + { + fmatch = p; + break; + } + if (p == entry->u->function_addrs) + break; + if ((p - 1)->low < p->low) + break; + --p; + } + if (fmatch == NULL) + return callback (data, pc, ln->filename, ln->lineno, NULL); + + function = fmatch->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 struct dwarf_sections *dwarf_sections, + int is_bigendian, + struct dwarf_data *altlink, + backtrace_error_callback error_callback, + void *data) +{ + struct unit_addrs_vector addrs_vec; + struct unit_addrs *addrs; + size_t addrs_count; + struct unit_vector units_vec; + struct unit **units; + size_t units_count; + struct dwarf_data *fdata; + + if (!build_address_map (state, base_address, dwarf_sections, is_bigendian, + altlink, error_callback, data, &addrs_vec, + &units_vec)) + return NULL; + + if (!backtrace_vector_release (state, &addrs_vec.vec, error_callback, data)) + return NULL; + if (!backtrace_vector_release (state, &units_vec.vec, error_callback, data)) + return NULL; + addrs = (struct unit_addrs *) addrs_vec.vec.base; + units = (struct unit **) units_vec.vec.base; + addrs_count = addrs_vec.count; + units_count = units_vec.count; + backtrace_qsort (addrs, addrs_count, sizeof (struct unit_addrs), + unit_addrs_compare); + /* No qsort for units required, already sorted. */ + + fdata = ((struct dwarf_data *) + backtrace_alloc (state, sizeof (struct dwarf_data), + error_callback, data)); + if (fdata == NULL) + return NULL; + + fdata->next = NULL; + fdata->altlink = altlink; + fdata->base_address = base_address; + fdata->addrs = addrs; + fdata->addrs_count = addrs_count; + fdata->units = units; + fdata->units_count = units_count; + fdata->dwarf_sections = *dwarf_sections; + 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 struct dwarf_sections *dwarf_sections, + int is_bigendian, + struct dwarf_data *fileline_altlink, + backtrace_error_callback error_callback, + void *data, fileline *fileline_fn, + struct dwarf_data **fileline_entry) +{ + struct dwarf_data *fdata; + + fdata = build_dwarf_data (state, base_address, dwarf_sections, is_bigendian, + fileline_altlink, error_callback, data); + if (fdata == NULL) + return 0; + + if (fileline_entry != NULL) + *fileline_entry = fdata; + + 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; +} |